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Magno MS, Olafsson J, Beining M, Moschowits E, Lagali N, Wolffsohn JS, Craig JP, Vehof J, Dartt DA, Utheim TP. Risk associated with treatments for meibomian gland dysfunction. Cont Lens Anterior Eye 2023; 46:101818. [PMID: 36754735 DOI: 10.1016/j.clae.2023.101818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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Vidal-Rohr M, Craig JP, Davies LN, Wolffsohn JS. The epidemiology of dry eye disease in the UK: The Aston dry eye study. Cont Lens Anterior Eye 2023; 46:101837. [PMID: 37003925 DOI: 10.1016/j.clae.2023.101837] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 03/01/2023] [Accepted: 03/11/2023] [Indexed: 04/03/2023]
Abstract
PURPOSE Cross-sectional studies on dry eye disease (DED) have relied on different diagnoses hindering conclusions about the disease epidemiology. This study offers an insight into DED epidemiology in the UK using prior and recent diagnostic recommendations. METHODS Study participants comprised 282 volunteers from Birmingham, UK (median 40 years, range 18-88 years, 56% females). DED was defined by the Tear Film Ocular Surface Dry Eye Workshop II (TFOS DEWS II) criteria, based on a positive symptom score with the Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI), and one of the following homeostasis markers: non-invasive tear break-up time of < 10 s (Oculus Keratograph 5M); the highest osmolarity value of ≥ 308 mOsm/L among eyes or an interocular osmolarity difference of > 8 mOsm/L (TearLab Osmolarity System); or > 5 corneal spots, >9 conjunctival spots or lower/upper lid-wiper-epitheliopathy staining of ≥ 2 mm length and ≥ 25% width (Oculus Keratograph 5 M). In addition, the Women's Health Study (WHS) criteria, based on symptoms or a prior dry eye diagnosis, was assessed. DED risk factors were gathered using a self-administered questionnaire. RESULTS DED prevalence by the TFOS DEWS II criteria was 32.1% (95% confidence interval 25.5-37.7% and 29.5% (95% confidence interval 24.4-35.1% by the WHS criteria. Female sex, systemic and/or ocular health conditions, short sleep duration and prolonged outdoor leisure time spent were significant DED risk factors (p ≤ 0.05). CONCLUSIONS Approximately one-third of the adult UK population have DED, aligning with the prevalence reported in multiple counties globally. Female sex, systemic/ocular health conditions, short sleep duration and prolonged outdoor leisure time are positive predictors of DED.
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Affiliation(s)
- M Vidal-Rohr
- Optometry and Vision Science, Aston University, Birmingham, UK
| | - J P Craig
- Department of Ophthalmology, The New Zealand National Eye Centre, University of Auckland, New Zealand
| | - L N Davies
- Optometry and Vision Science, Aston University, Birmingham, UK
| | - J S Wolffsohn
- Optometry and Vision Science, Aston University, Birmingham, UK.
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Samal A, Craig JP, Coradetti ST, Benz JP, Eddy JA, Price ND, Glass NL. Network reconstruction and systems analysis of plant cell wall deconstruction by Neurospora crassa. Biotechnol Biofuels 2017; 10:225. [PMID: 28947916 PMCID: PMC5609067 DOI: 10.1186/s13068-017-0901-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/05/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Plant biomass degradation by fungal-derived enzymes is rapidly expanding in economic importance as a clean and efficient source for biofuels. The ability to rationally engineer filamentous fungi would facilitate biotechnological applications for degradation of plant cell wall polysaccharides. However, incomplete knowledge of biomolecular networks responsible for plant cell wall deconstruction impedes experimental efforts in this direction. RESULTS To expand this knowledge base, a detailed network of reactions important for deconstruction of plant cell wall polysaccharides into simple sugars was constructed for the filamentous fungus Neurospora crassa. To reconstruct this network, information was integrated from five heterogeneous data types: functional genomics, transcriptomics, proteomics, genetics, and biochemical characterizations. The combined information was encapsulated into a feature matrix and the evidence weighted to assign annotation confidence scores for each gene within the network. Comparative analyses of RNA-seq and ChIP-seq data shed light on the regulation of the plant cell wall degradation network, leading to a novel hypothesis for degradation of the hemicellulose mannan. The transcription factor CLR-2 was subsequently experimentally shown to play a key role in the mannan degradation pathway of N. crassa. CONCLUSIONS Here we built a network that serves as a scaffold for integration of diverse experimental datasets. This approach led to the elucidation of regulatory design principles for plant cell wall deconstruction by filamentous fungi and a novel function for the transcription factor CLR-2. This expanding network will aid in efforts to rationally engineer industrially relevant hyper-production strains.
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Affiliation(s)
- Areejit Samal
- Institute for Systems Biology, Seattle, WA 98109 USA
- Energy Biosciences Institute, University of California Berkeley, Berkeley, CA 94704 USA
- The Institute of Mathematical Sciences, Homi Bhabha National Institute, Chennai, 600113 India
- The Abdus Salam International Centre for Theoretical Physics, 34151 Trieste, Italy
| | - James P. Craig
- Energy Biosciences Institute, University of California Berkeley, Berkeley, CA 94704 USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - Samuel T. Coradetti
- Energy Biosciences Institute, University of California Berkeley, Berkeley, CA 94704 USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
| | - J. Philipp Benz
- Energy Biosciences Institute, University of California Berkeley, Berkeley, CA 94704 USA
- Holzforschung München, TUM School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - James A. Eddy
- Institute for Systems Biology, Seattle, WA 98109 USA
| | | | - N. Louise Glass
- Energy Biosciences Institute, University of California Berkeley, Berkeley, CA 94704 USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
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Reilly MC, Qin L, Craig JP, Starr TL, Glass NL. Deletion of homologs of the SREBP pathway results in hyper-production of cellulases in Neurospora crassa and Trichoderma reesei. Biotechnol Biofuels 2015; 8:121. [PMID: 26288653 PMCID: PMC4539670 DOI: 10.1186/s13068-015-0297-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 07/24/2015] [Indexed: 05/05/2023]
Abstract
BACKGROUND The filamentous fungus Neurospora crassa efficiently utilizes plant biomass and is a model organism for genetic, molecular and cellular biology studies. Here, a set of 567 single-gene deletion strains was assessed for cellulolytic activity as compared to the wild-type parental strain. Mutant strains included were those carrying a deletion in: (1) genes encoding proteins homologous to those implicated in the Saccharomyces cerevisiae secretion apparatus; (2) genes that are homologous to those known to differ between the Trichoderma reesei hyper-secreting strain RUT-C30 and its ancestral wild-type strain; (3) genes encoding proteins identified in the secretome of N. crassa when cultured on plant biomass and (4) genes encoding proteins predicted to traverse the secretory pathway. RESULTS The 567 single-gene deletion collection was cultured on crystalline cellulose and a comparison of levels of secreted protein and cellulase activity relative to the wild-type strain resulted in the identification of seven hyper-production and 18 hypo-production strains. Some of these deleted genes encoded proteins that are likely to act in transcription, protein synthesis and intracellular trafficking, but many encoded fungal-specific proteins of undetermined function. Characterization of several mutants peripherally linked to protein processing or secretion showed that the hyper- or hypo-production phenotypes were primarily a response to cellulose. The altered secretome of these strains was not limited to the production of cellulolytic enzymes, yet was part of the cellulosic response driven by the cellulase transcription factor CLR-2. Mutants implicated the loss of the SREBP pathway, which has been found to regulate ergosterol biosynthesis genes in response to hypoxic conditions, resulted in a hyper-production phenotype. Deletion of two SREBP pathway components in T. reesei also conferred a hyper-production phenotype under cellulolytic conditions. CONCLUSIONS These studies demonstrate the utility of screening the publicly available N. crassa single-gene deletion strain collection for a particular phenotype. Mutants in a predicted E3 ligase and its target SREBP transcription factor played an unanticipated role in protein production under cellulolytic conditions. Furthermore, phenotypes similar to those observed in N. crassa were seen following the targeted deletion of orthologous SREBP pathway loci in T. reesei, a fungal species commonly used in industrial enzyme production.
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Affiliation(s)
- Morgann C Reilly
- />Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- />The Energy Biosciences Institute, University of California, Berkeley, CA 94720 USA
| | - Lina Qin
- />Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- />The Energy Biosciences Institute, University of California, Berkeley, CA 94720 USA
| | - James P Craig
- />Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- />The Energy Biosciences Institute, University of California, Berkeley, CA 94720 USA
| | - Trevor L Starr
- />Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- />The Energy Biosciences Institute, University of California, Berkeley, CA 94720 USA
| | - N Louise Glass
- />Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA
- />The Energy Biosciences Institute, University of California, Berkeley, CA 94720 USA
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Lopez-Nicora HD, Craig JP, Gao X, Lambert KN, Niblack TL. Evaluation of Cultivar Resistance to Soybean Cyst Nematode with a Quantitative Polymerase Chain Reaction Assay. Plant Dis 2012; 96:1556-1563. [PMID: 30727319 DOI: 10.1094/pdis-12-11-1083-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Heterodera glycines, the soybean cyst nematode, is a major pathogen of soybean. Effective management of this pathogen is contingent on the use of resistant cultivars; thus, screening for resistant cultivars is essential. The purpose of this research was to develop a method to assess infection of soybean roots by H. glycines with real-time quantitative polymerase chain reaction (qPCR). This method will serve as a prelude to differentiation of resistance levels in soybean cultivars. A reproducible inoculation method was developed by means of a sand column to provide active second-stage juveniles (J2). Two-day-old soybean roots were infested with 0 or 1,000 J2/ml distilled water per seedling. Twenty-four hours after infestation, the roots were surface-sterilized and genomic DNA (gDNA) was extracted. For the qPCR assay, a primer pair for the single copy gene HgSNO, which codes for a protein involved in the production of vitamin B6, was selected for H. glycines gDNA amplification within soybean roots. Compatible 'Lee 74', incompatible 'Peking', and cultivars with different levels of resistance to H. glycines were infested with 0 or 1,000 J2/ml distilled water per seedling. Twenty-four hours postinfestation, infected seedlings were transplanted into pasteurized soil. Subsequently, they were harvested at 1, 7, 10, 14, and 21 days postinfestation for gDNA extraction. With the qPCR assay, the time needed to differentiate highly resistant cultivars from the rest was reduced. Quantification of H. glycines infection by traditional means (numbers of females produced in 30 days) is a time-consuming practice. This qPCR assay has the potential to replace the traditional Female Index-based screening and improve precision in determining infection levels.
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Affiliation(s)
| | - James P Craig
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley 94720
| | - Xuebiao Gao
- Pasteuria Bioscience, Inc. 12085 Research Drive, Suite 185 Alachua, FL 32615
| | - Kris N Lambert
- Department of Crop Science, University of Illinois, Urbana 61801
| | - Terry L Niblack
- Department of Plant Pathology, Ohio State University, Columbus 43210
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Robins-Browne RM, Young CR, Levine MM, Craig JP. Microtiter enzyme-linked immunosorbent assay for immunoglobulin g cholera antitoxin in humans: sensitivity and specificity. Infect Immun 2010; 27:497-500. [PMID: 16558121 PMCID: PMC550793 DOI: 10.1128/iai.27.2.497-500.1980] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Serum samples were obtained from 92 informed, community volunteers before and 10, 21, and 28 days after they ingested 10(3) to 10(6)Vibrio cholerae of Inaba or Ogawa serotype and classical or El Tor biotype as part of a cholera vaccine development program. Pre- and postchallenge sera were examined for neutralizing antibody to cholera toxin by the rabbit skin permeability factor and adrenal cell techniques. Immunoglobulin G-binding antibodies to cholera toxin were quantitated by enzyme-linked immunosorbent assay (ELISA) in serum diluted 1:200. The results obtained in these cholera volunteers were compared with a negative control population comprising 30 people who ingested enteropathogenic Escherichia coli or E. coli which produced heat-stable but not heat-labile enterotoxin. Although all three antitoxin assays correlated closely with each other in both groups of volunteers, ELISA was more sensitive than either neutralization assay in detecting both subclinical and overt cholera infections. Seroconversion was demonstrated by ELISA in 58 of 66 (88%) volunteers who excreted V. cholerae, including 50 of 54 (93%) with clinical cholera, compared with 47 of 66 (71%) and 52 of 66 (79%) by the rabbit skin permeability factor and adrenal cell techniques, respectively. Although ELISA does not measure the toxin-neutralizing activity of antibodies directly, it provides a practical alternative to the rabbit skin permeability factor and adrenal cell assays.
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Affiliation(s)
- R M Robins-Browne
- The Center for Vaccine Development, Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, Maryland 21201
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Craig JP, Bekal S, Niblack T, Domier L, Lambert KN. Evidence for horizontally transferred genes involved in the biosynthesis of vitamin B(1), B(5), and B(7) in Heterodera glycines. J Nematol 2009; 41:281-90. [PMID: 22736827 PMCID: PMC3381462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Indexed: 06/01/2023] Open
Abstract
Heterodera glycines is a nematode that is highly adapted to manipulate and parasitize plant hosts. The molecular players involved in these interactions have only recently begun to be identified. Here, the sequencing of the second stage juvenile transcriptome, followed by a bioinformatic screen for novel genes, identified seven new genes involved in biosynthesis and salvage of vitamins B₁, B₅, and B₇. With no confirmed reports in the literature, each of these biosynthesis pathways is believed to have been lost in multicellular animals. However, eukaryotic-like introns in the genomic sequences of the genes confirmed eukaryotic origin and nematode-specific splice leaders found on five of the cDNAs confirmed their nematode origin. Two of the genes were found to be flanked by known nematode sequences and quantitative polymerase chain reactions on individual nematodes showed similar and consistent amplification between the vitamin B biosynthesis genes and other known H. glycines genes. This further confirmed their presence in the nematode genome. Similarity to bacterial sequences at the amino acid level suggested a prokaryotic ancestry and phylogenetic analysis of the genes supported a likely horizontal gene transfer event, suggesting H. glycines re-appropriated the genes from the prokaryotic kingdom. This finding complements the previous discovery of a vitamin B₆ biosynthesis pathway within the nematode. However, unlike the complete vitamin B₆ pathway, many of these vitamin B pathways appear to be missing the initial enzymes required for full de novo biosynthesis, suggesting that initial substrates in the pathways are obtained exogenously. These partial vitamin B biosynthesis enzymes have recently been identified in other single-celled eukaryotic parasites and on rhizobia symbiosis plasmids, indicating that they may play an important role in host-parasite interactions and survival within the plant environment.
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Affiliation(s)
- James P Craig
- University of Illinois, Crop Sciences, Illinois, USA
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Craig JP, Bekal S, Hudson M, Domier L, Niblack T, Lambert KN. Analysis of a horizontally transferred pathway involved in vitamin B6 biosynthesis from the soybean cyst nematode Heterodera glycines. Mol Biol Evol 2008; 25:2085-98. [PMID: 18586696 DOI: 10.1093/molbev/msn141] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Heterodera glycines is an obligate plant parasite capable of biochemically and developmentally altering its host's cells in order to create a specialized feeding cell. Although the exact mechanism of feeding cell morphogenesis remains a mystery, the nematode's ability to manipulate the plant is thought to be due in part to horizontal gene transfers (HGTs). A bioinformatic screen of the nematode genome has revealed homologues of the genes SNZ and SNO, which comprise a metabolic pathway for the de novo biosynthesis of pyridoxal 5'-phosphate, the active form of vitamin B(6) (VB(6)). Analysis of the 2 genes, HgSNZ and HgSNO, show that they contain nematode-like introns, generate polyadenylated mRNAs, and map to the soybean cyst nematode genetic linkage map, indicating that they are part of the nematode genome. However, gene synteny, protein homology, and phylogenetic evidence suggest prokaryotic origin. This would represent the first case of the HGT of a complete pathway into a nematode or terrestrial animal. VB(6) acts as a cofactor in over 140 different enzymes, and recent studies point toward an important role as a potent quencher of reactive oxygen species. With H. glycines' penchant for acquiring parasitism genes through HGT along with the absence of this pathway in other land-based animals suggests a specific need for VB(6) which may involve the parasite-host interaction.
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Affiliation(s)
- James P Craig
- Department of Crop Sciences, University of Illinois, Urbana, USA
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Bekal S, Craig JP, Hudson ME, Niblack TL, Domier LL, Lambert KN. Genomic DNA sequence comparison between two inbred soybean cyst nematode biotypes facilitated by massively parallel 454 micro-bead sequencing. Mol Genet Genomics 2008; 279:535-43. [PMID: 18324416 DOI: 10.1007/s00438-008-0331-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2007] [Revised: 01/29/2008] [Accepted: 02/03/2008] [Indexed: 10/22/2022]
Abstract
Heterodera glycines, the soybean cyst nematode (SCN), is a damaging agricultural pest that could be effectively managed if critical phenotypes, such as virulence and host range could be understood. While SCN is amenable to genetic analysis, lack of DNA sequence data prevents the use of such methods to study this pathogen. Fortunately, new methods of DNA sequencing that produced large amounts of data and permit whole genome comparative analyses have become available. In this study, 400 million bases of genomic DNA sequence were collected from two inbred biotypes of SCN using 454 micro-bead DNA sequencing. Comparisons to a BAC, sequenced by Sanger sequencing, showed that the micro-bead sequences could identify low and high copy number regions within the BAC. Potential single nucleotide polymorphisms (SNPs) between the two SCN biotypes were identified by comparing the two sets of sequences. Selected resequencing revealed that up to 84% of the SNPs were correct. We conclude that the quality of the micro-bead sequence data was sufficient for de novo SNP identification and should be applicable to organisms with similar genome sizes and complexities. The SNPs identified will be an important starting point in associating phenotypes with specific regions of the SCN genome.
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Affiliation(s)
- Sadia Bekal
- Crop Sciences, University of Illinois, 1102 S. Goodwin Ave., Urbana, IL 61801, USA
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Ku JYF, Danesh-Meyer HV, Craig JP, Gamble GD, McGhee CNJ. Comparison of intraocular pressure measured by Pascal dynamic contour tonometry and Goldmann applanation tonometry. Eye (Lond) 2005; 20:191-8. [PMID: 15803173 DOI: 10.1038/sj.eye.6701849] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
AIMS To compare the intraocular pressure (IOP) measurements obtained using the Pascal dynamic contour tonometer (PDCT) with the standard Goldmann applanation tonometer (GAT) and to correlate these with central corneal thickness (CCT) in patients with normal corneas. METHODS A prospective, masked, comparative case series of 116 eyes from patients attending a glaucoma clinic. IOP was measured with PDCT by one examiner and with GAT by a masked, independent examiner. A mean of six CCT readings was used for analysis. RESULTS IOP measured by the two instruments correlated significantly (r=0.77; P<0.0001). IOP measured by GAT correlated strongly with CCT (r=0.37, P=0.0001) whereas the relationship between IOP measured by PDCT and CCT approached significance (r=0.17, P=0.073). The differences between GAT and PDCT measured IOP also correlated strongly with CCT (r=0.37, P<0.0001). The 95% limits of agreement between GAT and PDCT were +/-4.2 mmHg. Dividing the eyes into three groups on the basis of CCT, demonstrated those in the thickest tertile showed a poorer agreement between instruments and the GAT measured significantly higher IOP in this group (P=0.003) while the PDCT showed no significant differences with different CCTs (P=0.37). CONCLUSION Demonstration of the relative independence of PDCT IOP measurements from CCT supports a potential clinical role for this instrument, particularly for subjects with CCT outside the normal range.
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Affiliation(s)
- J Y F Ku
- Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Müller A, Craig JP, Grupcheva CN, McGhee CNJ. The effects of corneal parameters on the assessment of endothelial cell density in the elderly eye. Br J Ophthalmol 2004; 88:325-30. [PMID: 14977761 PMCID: PMC1772027 DOI: 10.1136/bjo.2003.019315] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2003] [Indexed: 11/04/2022]
Abstract
BACKGROUND The possible impact of corneal thickness, curvature, and size on the measurement of endothelial cell density (ECD) has largely been ignored in the normal eye. The aim of this study was to investigate the possible impact of the main corneal parameters on the analysis of ECD values at the central, superior, and temporal parts of the corneal surface. METHODS All 75 participants (52 females, 23 males) were assessed as part of a pre-cataract surgery investigation. The mean age was 75.7 (SD 10.9) years. Confocal microscopy was used to measure ECD and the percentage of six sided cells at the central, superior, and temporal parts of the cornea. The Orbscan II topography system was used to measure corneal thickness, topography, and horizontal corneal diameter. RESULTS The mean central ECD measured was 2488 (SD 301) cells/mm(2), compared with 2525 (SD 505) cells/mm(2) in the temporal cornea and 2639 (SD 398) cells/mm(2) in the superior cornea. The regional differences in ECD were not significant (p>0.14). The central ECD was significantly correlated to the central (mean 0.593 (SD 0.039) mm, p = 0.021) as well as the temporal (0.628 (SD 0.039) mm, p<0.001) and the superior corneal thickness (SD 0.644 (SD 0.048) mm, p = 0.018). The mean corneal curvature at the centre (7.7 (SD 0.34) mm, p = 0.002) as well as 3 and 5 mm from the apex was significantly related to ECD (p = 0.008 and p = 0.009, respectively). CONCLUSIONS The study suggests that in an older population, lower ECD values would be expected in thinner and/or steeper corneas.
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Affiliation(s)
- A Müller
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand.
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Abstract
AIMS To identify the demographic and visual function of patients on the reserve waiting list for cataract surgery at a large public hospital within New Zealand and to determine the ultimate outcome of those on a priority-based, rationed, health-care waiting list. METHODS Patients from a defined geographical population, placed on a reserve waiting list for possible cataract surgery, during the period January 1997 to March 2000, were invited to attend for further clinical assessment and asked to complete a visual assessment questionnaire. RESULTS Of 193 patients in the pilot study group who had been on the reserve waiting list for a mean of 18.2 +/- 11.6 months (range 0.1-62.7 months), only 94 (49%) were deemed suitable for, and subsequently underwent, surgery in the public sector. Forty-nine (25%) had undergone surgery earlier, the majority of these (84%) in the private sector. A further 23 (12%) patients were deceased, four (2%) declined surgery and in six (3%) cataract surgery was no longer indicated. The remaining 11 (6%) patients could not be traced. Patients still awaiting surgery had a mean age of 77.2 years (range 48-95 years). Fifty-four were women. Vision had deteriorated by a mean of 0.05 LogMAR units, from Snellen equivalent 6/30 at listing to 6/36, over this time. CONCLUSIONS Current methods of prioritization for cataract surgery are imperfect, as are the resources for performing adequate levels of cataract surgery. Analysis of a residual waiting list for cataract surgery highlights that the majority (51%) do not ultimately progress to cataract surgery in the public sector for a variety of reasons. During a mean waiting time of 1.5 years vision further deteriorates in this predominantly older population.
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Affiliation(s)
- A F Riley
- Discipline of Ophthalmology, University of Auckland, New Zealand
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Abstract
PURPOSE To determine patient demographics and the ocular biometric parameters in patients presenting for cataract surgery within the public hospital system, in a defined New Zealand population. METHOD Prospective study of 502 eyes of 488 consecutive patients undergoing cataract surgery. A clinical assessment, including refraction, keratometry (K), A-scan ultrasound and Orbscan II computerized topography was performed on each eye. RESULTS The mean age of the group was 74.9 +/- 9.8 years (mean +/- SD) with a female predominance (62%). Ethnic origin included 72% European, 8% Maori, 10% Pacific Islander, 4% Asian, 3% Indian and 3% other ethnic origins. The mean Log MAR visual acuity of eyes prior to cataract surgery was 0.88 +/- 0.57 (approximately 6/48(-1)). Corneal topographic (keratometric) maps were classified into five groups: 34% round, 10% oval, 31% symmetrical bow tie, 12% asymmetrical bow tie and 13% irregular. The mean steepest K measurement was 44.1 +/- 1.7 D, the median keratometric astigmatism 0.89 D (range 0.0-6.5 D) and the steepest corneal meridian was horizontal in 50% and vertical in 43%. Seven per cent of corneas were spherical. Refraction revealed a mean sphere of 0.0 +/- 3.1 D and a mean cylinder of -1.2 (range 0.0-7.5 D). Refractive astigmatism was with-the-rule in 15%, against-the-rule in 50% and oblique in 15%, with 20% spherical. Axial length was a mean of 23.14 +/- 1.03 mm. CONCLUSION Patients presenting for cataract surgery in this study were predominantly elderly, female, of European Caucasian ethnicity and exhibited relatively poor corrected visual acuity in the affected eye. Interestingly, 41% of eyes demonstrated bow-tie topographic patterns, largely exhibiting with-the-rule astigmatism. However, assessment by keratometry or refraction highlighted against-the-rule more frequently; this may have implications for combined cataract and astigmatic surgery. The mean axial length was slightly shorter than expected for a group of predominantly European ethnic origin, although the mean refractive error was emmetropic.
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Affiliation(s)
- A F Riley
- Discipline of Ophthalmology, University of Auckland, New Zealand
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Chakrabarti HS, Craig JP, Brahma A, Malik TY, McGhee CN. Comparison of corneal thickness measurements using ultrasound and Orbscan slit-scanning topography in normal and post-LASIK eyes. J Cataract Refract Surg 2001; 27:1823-8. [PMID: 11709257 DOI: 10.1016/s0886-3350(01)01089-6] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
PURPOSE To compare corneal thickness measurements made by ultrasonic and slit-scanning techniques in normal eyes and in eyes after laser in situ keratomileusis (LASIK). SETTING Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Dundee, Scotland. METHODS Central corneal thickness (CCT) was measured in 101 eyes of 59 normal subjects and in 30 eyes of 21 post-LASIK patients. Measurements were made with an Orbscan slit-scanning elevation topographer and immediately afterward with an ultrasound pachymeter. RESULTS The difference in mean CCT between ultrasound (538.0 microm +/- 36.7 [SD]) and Orbscan (566.6 +/- 40.7 microm) pachymetry was statistically significant (P <.001) in the normal eyes; the Orbscan measurement was approximately 28 microm higher than that of the ultrasound pachymeter. The difference in mean CCT between the ultrasound and the slit-scanning techniques was also statistically significant in the post-LASIK eyes (mean values 475.3 +/- 50.3 microm and 461.9 +/- 74.2 microm, respectively; P <.0001). Differences in CCT in individual subjects were much more variable in the post-LASIK eyes than in the normal eyes. The Bland and Altman method for assessing clinical agreement between 2 instruments showed that in 95% of cases, the CCT measurements with both instruments would be within 65 microm in normal eyes and 150 microm in post-LASIK eyes. CONCLUSION Central corneal thickness measurements were, on average, 28 microm higher with the Orbscan than with the ultrasound pachymeter in normal eyes and 13 microm lower in post-LASIK eyes. The degree of variability within each group indicated that these 2 techniques are not clinically comparable, precluding interchangeable use of their data in planning or assessing corneal surgery.
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Affiliation(s)
- H S Chakrabarti
- Department of Ophthalmology, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland, UK
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15
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Grupcheva CN, Malik TY, Craig JP, Sherwin T, McGhee CN. Microstructural assessment of rare corneal dystrophies using real-time in vivo confocal microscopy. Clin Exp Ophthalmol 2001; 29:281-5. [PMID: 11720152 DOI: 10.1046/j.1442-9071.2001.00434.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To analyse and describe three cases of rare corneal dystrophy and highlight their in vivo microstructural features. METHODS Subject 1 was diagnosed with a posterior stromal fleck corneal dystrophy Two of her three children were also affected. Subjects 2 and 3 exhibited an almost identical clinical appearance on biomicroscopic examination, such that both clinically were diagnosed as having pre-Descemet's dystrophies. All subjects underwent in vivo confocal microscopy and approximately 300 sequential digital images were obtained and analysed for each cornea. RESULTS In vivo confocal microscopy of subject 1 demonstrated an abnormal appearance of numerous large ovoid particles, measuring 50-70 microm in diameter in the mid and posterior stroma as well as smaller hyperreflective dot-like intracellular deposits, of less than 1 microm diameter. Despite the near-identical clinical appearance, subjects 2 and 3 could be clearly differentiated by in vivo confocal microscopy. Subject 2 exhibited small, irregular, optically dense particles, mainly in the anterior stroma, whereas subject 3 possessed classical involvement of the stroma immediately adjacent to Descemet's membrane, with numerous regular small, hyperreflective particles. CONCLUSIONS The ability of in vivo confocal microscopy to localize and accurately measure various elements in different corneal layers may help to resolve whether abnormalities are intra- or extracellular, and aid clearer differentiation of rare corneal disorders.
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Affiliation(s)
- C N Grupcheva
- Discipline of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
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16
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Abstract
To identify features of posterior polymorphous dystrophy (PPMD) by in vivo confocal microscopy, the corneas of a female patient with PPMD were exam ned using slit-lamp biomicroscopy and slit-scanning in vivo confocal microscopy. Characteristic endothelial vesicular and band lesions were seen clinically and easily identified using in vivo confocal microscopy. However endothelial pleomorphism, an increased density and reflectance of posterior stromal keratocytes, and prominence of corneal nerves were also delineated. In vivo confocal microscopy enhances clinicopathological diagnosis and follow up of corneal dystrophies with subtle clinical presentations, such as PPMD.
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Affiliation(s)
- C N Grupcheva
- Discipline of Ophthalmology, University of Auckland, New Zealand.
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Grupcheva CN, Malik TY, Craig JP, McGhee CN. In vivo confocal microscopy of corneal epithelial ingrowth through a laser in situ keratomileusis flap buttonhole. J Cataract Refract Surg 2001; 27:1318-22. [PMID: 11524207 DOI: 10.1016/s0886-3350(01)00753-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We report a case of epithelial ingrowth through a buttonhole 6 months after laser in situ keratomileusis. Elevation topography showed irregular astigmatism and an unreliable pachymetric map. In vivo confocal microscopy showed an epithelial basal cell mosaic with prominent borders and distinct nuclei. No corneal nerves were identified in any image. Cells in the anterior stroma possessed bright, reflective nuclei and appeared to form clusters. The interface between the stromal bed and the flap had formation of nests of fibrotic tissue and epithelial cells.
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Affiliation(s)
- C N Grupcheva
- Discipline of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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18
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Abstract
The purpose of this study was to demonstrate microstructural differences between clinically similar, but aetiologically different, cases of corneal oedema in four subjects. In vivo confocal microscopy highlighted oedema of the basal epithelium, prominent nerve-keratocyte interactions, and typical 'epithelialization' of the endothelium in a case of iridocorneal endothelial syndrome; however, a similar microstructural appearance was observed in a case of presumed herpetic disciform keratitis. The latter diagnosis was subsequently revised on this basis. Confocal examination of Fuchs' endothelial dystrophy demonstrated oedema of the basal epithelium, prominent wing cells, anterior stromal alterations, fibrosis of Descemet's membrane and a typical 'strawberry' appearance of the endothelium. In contrast, in vivo microstructural examination of bilateral keratoconus with hydrops confirmed oedema mainly involving the epithelium and anterior stroma. In vivo confocal microscopy allows the clinician to observe the living cornea at a microstructural level and to better diagnose and differentiate borderline or unusual cases of corneal oedema.
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Affiliation(s)
- C N Grupcheva
- Discipline of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
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Brahma A, McGhee CN, Craig JP, Brown AD, Weed KH, McGhee J, Brown R. Safety and predictability of laser in situ keratomileusis enhancement by flap reelevation in high myopia. J Cataract Refract Surg 2001; 27:593-603. [PMID: 11311630 DOI: 10.1016/s0886-3350(01)00765-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To evaluate the safety and predictability of laser in situ keratomileusis (LASIK) retreatment following primary procedures for high myopia and astigmatism. SETTING Corneal Diseases and Excimer Laser Research Unit, Department of Ophthalmology, University of Dundee, Dundee, United Kingdom. METHODS This prospective observational study of retreatment comprised a cohort of 109 eyes having primary LASIK for high myopia and astigmatism with a spherical equivalent (SE) of -9.70 diopters (D) +/- 4.06 (SD). Twenty-four eyes (22%) with an initial myopic SE of -9.83 +/- 3.50 D, a comparable subset of the entire group (P < .05), had retreatment for residual myopia (-3.02 +/- 2.17 D) to improve uncorrected visual acuity (UCVA) by reelevating the corneal flap and ablating the stromal bed. RESULTS The mean follow-up after retreatment was 12.8 +/- 5.1 months (range 1.5 to 24 months; 19 eyes >/=6 months, 13 eyes > or = 12 months). The mean myopic SE was reduced to +0.53 +/- 0.62 D at 1 week, +0.05 +/- 0.50 D at 1 month, +0.30 +/- 0.50 D at 6 months, and +0.18 +/- 0.42 D at the latest follow-up, 12.8 months. At the latest review, 62% of eyes were within +/-0.50 D of emmetropia and 100% were within +/-1.00 D. The mean refraction did not alter statistically between 1 week and subsequent times. The mean UCVA improved from 6/30 prior to retreatment to 6/9 at the latest follow-up. Uncorrected visual acuity of 6/6 or better, 6/9 or better, and 6/12 or better was achieved by 33.0%, 75.0%, and 95.8% of eyes, respectively. No significant complications that led to a loss of best corrected visual acuity were encountered, although retreatment procedures were more uncomfortable than primary procedures and self-limiting; epithelial ingrowth that did not threaten vision was common, and 2 patients complained of nighttime visual symptoms. CONCLUSIONS Retreatment of residual myopia by reelevating the flap was relatively safe and predictable, with a low risk of sight-threatening complications. However, longer term studies may be required to detect late complications.
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Affiliation(s)
- A Brahma
- Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Dundee, United Kingdom
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20
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Craig JP. An optometrist's personal perspective of aspects of refractive surgery. Cont Lens Anterior Eye 2001; 24:34-40. [PMID: 16303451 DOI: 10.1016/s1367-0484(01)80007-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2000] [Revised: 11/02/2000] [Indexed: 11/24/2022]
Abstract
The latter part of the last century has seen significant evolution in the area of refractive surgery, such that is has become a viable alternative to contact lenses, or spectacles, for an increasing number of patients. The developments of the principal techniques, in this ever-expanding field, are reviewed, and the increasing rôle of the optometrist in the pre-, intra- and post-operative management of the refractive surgery patient is described, based upon the author's personal experience within a non-profit, refractive surgery setting. In addition to highlighting pertinent features of the objective evaluation of patients, the importance of subjective assessment, pre- and postoperatively, is discussed, in terms of maximising post-surgery patient satisfaction. The scope for future research in this dynamic area is also considered.
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Affiliation(s)
- J P Craig
- Discipline of Ophthalmology, University of Auckland, New Zealand.
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21
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Abstract
PURPOSE To determine whether the more rapid cooling of the tear film in dry eyes is related to other tear film parameters, a battery of tear physiology tests was performed on dry eye patients and control subjects. METHODS Tear evaporation rate was measured with a modified Servomed (vapour pressure) evaporimeter and ocular temperature with an NEC San-ei 6T62 Thermo Tracer in 9 patients diagnosed as having dry eye and in 13 healthy control subjects. Variability in temperature across the ocular surface was described by the temperature variation factor (TVF). Lipid layer structure and tear film stability were assessed with the Keeler Tearscope and tear osmolality was measured by freezing point depression nanolitre osmometry. RESULTS The data were explored by principal component analysis. The subjects with and without dry eye could be separated into two distinct groups entirely on the basis of their tear physiology. Dry eye patients exhibited higher tear evaporation rates, osmolalities and TVF, lower tear film stabilities and poorer-quality lipid layers than the control subjects. A significant linear relationship was found to exist between tear evaporation rate and TVF for all subjects (R2 = 0.242, p = 0.024). CONCLUSIONS Rapid cooling of the tear film in dry eyes appears to be related to the reduced stability of the tears and the increased rate of evaporation. The higher latent heat of vaporisation, associated with the increased evaporation in dry eyes, may account for the increased rate of cooling of the tear film in this condition.
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, UK
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McGhee CN, Craig JP, Sachdev N, Weed KH, Brown AD. Functional, psychological, and satisfaction outcomes of laser in situ keratomileusis for high myopia. J Cataract Refract Surg 2000; 26:497-509. [PMID: 10771222 DOI: 10.1016/s0886-3350(00)00312-6] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To identify factors that motivate patients to seek laser in situ keratomileusis (LASIK) treatment for myopia and establish subjective levels of functional improvement and satisfaction across a range of indices after LASIK surgery. SETTING The Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland. METHODS In this questionnaire-based, cross-sectional study, an anonymous 34-item questionnaire was forwarded to 50 consecutive patients in a prospective study who had had LASIK for high myopia by a single surgeon at a single center. The questionnaire used visual analog scales, anchored at each end by an adjectival descriptor. The mean preoperative myopia was -10.7 diopters +/- 4.4 (SD). Seventy-six percent of eyes (83% of patients) achieved post-LASIK uncorrected visual acuity (UCVA) of 6/12 or better; 1 eye lost 2 lines of corrected Snellen visual acuity. RESULTS A 98% reply rate was achieved. The most common motivating factor for pursuing LASIK was to improve UCVA (88%); only 21% rated improved cosmesis as an important motive. Most patients (81% to 100%) reported functional improvement across the spectrum of visual tasks assessed, although 8.8% reported difficulty with nighttime driving. Ninety-six percent felt their UCVA was as good as anticipated, 97.9% were satisfied with the speed of visual improvement, 93.8% achieved the goals for which they had surgery, 97.9% reported an improved quality of life, and 97.9% were satisfied with the overall outcome of LASIK. CONCLUSIONS Using an anonymous, wide-ranging questionnaire, high levels of functional improvement and satisfaction with the speed of visual recovery and outcome were reported by patients after LASIK for high myopia. Nighttime driving symptoms of variable severity were, however, noted by 8.8% of patients, despite high levels of satisfaction with other aspects of visual function.
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Affiliation(s)
- C N McGhee
- Corneal Diseases and Excimer Laser Research Unit, University of Dundee Department of Ophthalmology, Ninewells Hospital and Medical School, Dundee, Scotland, UK
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23
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Abstract
PURPOSE To evaluate the efficacy of excimer laser in situ keratomileusis (LASIK) in the treatment of refractive errors after penetrating keratoplasty. METHODS Eight eyes underwent LASIK after a mean 71 months (SD 60) following the initial penetrating keratoplasty. A full ophthalmic assessment was performed before LASIK and at 1 week, 1, 3, 6, and 12 months after surgery. Mean follow-up was 8.6 months (SD 3.2). RESULTS No eyes lost any Snellen lines of best spectacle-corrected visual acuity at the latest follow-up. Mean reduction in spherical equivalent refraction was 91% from -6.79 D (SD 4.17) to -0.64 D (SD 1.92) and mean reduction of cylinder was 72% from -6.79 D (SD 3.28) to -1.93 D (SD 1.17) at 6 months. Mean surgically induced astigmatism was 5.50 D (SD 2.42) and the index of surgically induced astigmatism divided by the initial cylinder expressed as a percentage was 81%. Mean outcome indices were: correction index 0.87, index of success 0.31, and angle of error 0.95 degrees. Three eyes (43%) achieved a spherical equivalent refraction of +/-0.50 D and 4 eyes (57%) achieved a spherical equivalent refraction of +/-1.00 D of emmetropia. CONCLUSIONS The efficacy of LASIK after penetrating keratoplasty was good compared to incisional or surface based excimer laser methods and has the advantage of reducing the myopic spherical equivalent refraction in addition to astigmatism, thus improving the uncorrected visual acuities.
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Affiliation(s)
- P Y Koay
- Corneal Diseases and Excimer Laser Research Unit, University of Dundee, Scotland, United Kingdom.
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25
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, Scotland
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26
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Affiliation(s)
- E I Pearce
- Department of Vision Sciences, Glasgow Caledonian University, Scotland, United Kingdom
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27
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Affiliation(s)
- A Tomlinson
- Department of Vision Sciences, Glasgow Caledonian University, Scotland, United Kingdom
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28
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Abstract
Studies in humans and experimental animals indicate that infection with schistosomes results in impaired immune response to a variety of antigens. Since artificial immunization against a number of infections is frequently attempted in populations in which schistosomiasis is endemic, we have attempted to determine whether this impairment could be demonstrated in response to a commonly used immunogen. We have compared the serum antitoxin response to diphtheria toxoid (DTd) in normal, uninfected mice with that in mice bearing schistosome infections of different duration. Animals were infected with 100 Schistosoma mansoni cercariae 16, 12, 8, 4 and 2 weeks prior to, on the same day as, and 4 weeks after the first of three 1 microgram doses of DTd given at 3 week intervals. The antitoxin level of each mouse was taken as the mean of two sera obtained 1 and 2 weeks after the 3rd dose of DTd. The mean antitoxin level in uninfected-immunized control mice was 0.0457 Antitoxin Units (AU) ml-1. 71% of mice in this group developed antitoxin levels > or = 0.01 AU ml-1. Only 28% of the infected-immunized mice achieved antitoxin levels > or = 0.01 AU ml-1. In infected-immunized mice with infections of all durations, both the percentage of mice with > or = 0.01 AU ml-1 (0 to 50%) and mean antitoxin levels (0.003 to 0.016 AU ml-1) were lower than in uninfected-immunized mice. Antitoxin levels in animals infected 16, 12, 8 and 2 weeks prior to, simultaneously with, and 4 weeks after the first dose of DTd were significantly lower (P = < 0.05) than those of controls. Mice infected 4 weeks prior to the first dose of DTd had antitoxin levels 64% below controls but this difference was not significant. If similar immunosuppression occurs in human schistosomiasis, these findings may have implications for childhood immunization programs in areas where schistosomiasis is endemic.
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Affiliation(s)
- M A Haseeb
- Department of Microbiology and Immunology (Box # 44), State University of New York, Brooklyn 11203, USA
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29
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Abstract
PURPOSE Previous work on rabbits has demonstrated a four-fold increase in tear evaporation when the tear lipid layer is removed. However, in vitro work has suggested that the lipid layer does not play a role in retarding evaporation of the aqueous layer. The importance of the lipid layer in human tear film stability and evaporation was determined in the current study by measurement of these parameters in the same individuals. METHODS The left eyes of 161 normal and dry eye subjects (72 males, 89 females), with an age range of 13 to 85 years, were examined. Tear evaporation was derived from the vapor pressure gradient measured with a modified Servomed evaporimeter. Lipid layer structure and noninvasive break-up time (NIBUT) were assessed clinically, by specular reflection, with the Keeler Tearscope. Lipid layer structure was categorized into marmoreal (open and closed meshwork), flow, amorphous, and colored fringe (normal and abnormal) patterns. These observed patterns reflect lipid layer thickness. Ambient temperature and relative humidity remained fairly constant throughout the experiment. RESULTS Tear evaporation rate was found to vary significantly with different lipid layer patterns. Eyes with no visible lipid layer, or exhibiting an abnormal colored fringe pattern (with clumping of lipid amidst areas of little or no lipid cover), demonstrated a significantly higher rate of evaporation of the tear film (p < 0.001). There were no significant differences amongst the remainder of the patterns. The NIBUT was also found to vary significantly with lipid layer pattern (p < 0.001), with the absent or abnormal colored fringe lipid patterns exhibiting the poorest stability. CONCLUSIONS Where the human lipid layer is absent, or is not confluent, and the tear film is unstable, tear evaporation is increased four-fold. However, where there is a stable, intact lipid layer, regardless of lipid thickness, tear evaporation is retarded.
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, Scotland, UK
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30
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Craig JP, Blades K, Patel S. Tear lipid layer structure and stability following expression of the meibomian glands. Ophthalmic Physiol Opt 1995; 15:569-74. [PMID: 8594528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In a masked investigation, tear lipid layer structure and non-invasive break-up time (NIBUT) of both eyes of 40 normal subjects were assessed with the Keeler Tearscope after unilateral manual expression of meibomian fluid from the lower lid. The HIRCAL grid (modified keratometer mire) provided the additional measure of tear thinning time (TTT). Twenty untreated normal subjects formed the control group. No difference in lipid layer structure or stability was observed between the right and left eyes of the controls. The NIBUT of the treated eyes was significantly higher than that of the untreated contralateral eyes which was, in turn, greater than that of the control eyes. Lipid layer thickness in the treated eyes was significantly higher than that in the untreated contralateral eyes and the controls but did not differ between the latter two groups. The TTT of the treated eyes was not significantly different from that of the untreated contralateral eyes but both were significantly higher than that of the controls. Unilateral meibomian gland expression results in increased lipid layer thickness and tear stability. A possible reason for the slight increase in tear stability in the untreated contralateral eyes is a complimentary reflex lacrimation induced by mechanical stimulation of the treated eye. Differences between the results of the Tearscope and HIRCAL grid are attributed to differences in the techniques of tear stability measurement.
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, UK
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31
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Abstract
Certain aspects of tear physiology change with age (reflex secretion and stability), whereas others remain unchanged (tear volume, evaporation rate, basal tear production). To establish the variation in tear osmolality with age, 0.2 to 0.4 microliter samples were collected from 50 normal males and 50 normal females (age range 17 to 75 years). Nanoliter aliquots of the samples were analyzed by freezing point depression nanoliter osmometry. Mean tear osmolality for the whole group was 303.6 +/- 13.0 mOsm/kg and was not significantly affected by age (r2 = 0.014, p = 0.378). For males the mean was 307.1 +/- 14.4 and for females 300.1 +/- 10.4 mOsm/kg, a significant gender difference (p = 0.006). Males under age 41 had tear osmolality which was not significantly different from that of males over 41 years of age (307.7 +/- 15.6 and 305.7 +/- 11.5 mOsm/kg, respectively, p = 0.671) but the mean tear osmolality for females under age 41 years (297.6 +/- 11.2 mOsm/kg) was significantly different from that of older females (304.8 +/- 6.7 mOsm/kg, p = 0.017). There was no significant correlation between age and osmolality for males (r2 = 0.003, p = 0.699), but there was a significant correlation for females (r2 = 0.159, p = 0.004). Males under age 41 years have a significantly higher mean tear osmolality than females under 41 years of age (p = 0.003). The age and gender differences found for tear osmolality can be accounted for by the low values in young females, which may be related to the increased tear flow observed in young females. A reduction in this high flow rate to a more "normal" level in older females may account for the rise in tear osmolality to a level which is not significantly different from that of older males. Generally in normal eyes, the osmolality of tears remains within normal limits and is not affected by age.
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, Scotland, UK
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32
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Abstract
Tear osmolality measurement, as a basic index of lacrimal physiology, is technically difficult. We investigated a simple, digital nanoliter technique of critical angle refractive index measurement. After initial comparison of the techniques with aqueous NaCl (0.5 to 1.4%), 3 successive tear samples were obtained from each of 40 normal, noncontact lens wearing subjects, aged 17 to 63 years, for analysis by nanoliter osmometry and digital refractometry. In addition, tear lactoferrin concentration was estimated with the Lactoplate immunoassay. For the range of NaCl concentrations tested, osmolality and refractive index measurements were highly correlated with concentration, and with each other. For 0.9% NaClaq the mean value of osmolality was 292.0 mOsm/kg and refractive index was 1.33419. For human tears average values were found to be: for osmolality, 303.7 +/- 22.9 mOsm/kg; for refractive index, 1.33698 +/- 0.00110; and for lactoferrin level, 1.64 +/- 0.47 mg/ml. No statistically significant correlation was obtained between either refractive index or lactoferrin level and osmolality, but refractive index and lactoferrin level were significantly correlated (r = 0.64, p < 0.001). The high correlation of refractometry and osmolality for aqueous NaCl indicates comparability of the techniques for this solution, but this does not apply to human tears. Unlike tear osmolality, tear refractive index is dependent to a greater extent upon composition, as is suggested by its correlation with lactoferrin level. Therefore, refractometry is not acceptable as a direct alternative to osmometry in the assessment of lacrimal function.
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Affiliation(s)
- J P Craig
- Department of Vision Sciences, Glasgow Caledonian University, Scotland, UK
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Abstract
A photographic questionnaire has been used to investigate whether or not clinicians have realistic expectations of their ability to distinguish optic discs associated with glaucomatous visual field loss from discs of healthy eyes. The questionnaire consisting of 30 non-stereoscopic fundus photographs from 15 patients was administered to 40 ophthalmologists of varying experience and 10 optometrists. Each group displayed large discrepancies between their expected and achieved scores suggesting that clinicians may overestimate their ability to recognize the glaucomatous optic disc. This could lead to diagnostic errors especially in cases where tonometric and visual field parameters are considered equivocal. An over-reliance on the cup/disc ratio appeared to be the most likely cause of error.
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Affiliation(s)
- D M Montgomery
- Tennent Institute of Ophthalmology, University of Glasgow, Western Infirmary, UK
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34
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Abstract
In today's information explosion environment, the health sciences librarian is increasingly placed in the role of interpreting, translating, and evaluating information for clientele. With this emerging role and the burgeoning of fee for service programs, the question of information malpractice liability becomes an increasingly important issue. This paper explores the basis for legal actions against librarians and offers some precautionary measures to help protect against such legal action.
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Affiliation(s)
- M Puckett
- Medical Center Library, Louisiana State University School of Medicine, Shreveport
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35
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Rollins SD, Craig JP. Gold-associated lymphadenopathy in a patient with rheumatoid arthritis. Histologic and scanning electron microscopic features. Arch Pathol Lab Med 1991; 115:175-7. [PMID: 1899556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The histologic features of adenopathy associated with intramuscular injections of gold sodium thiomalate in a woman with rheumatoid arthritis are presented. We believe that the light microscopic features of the above process are sufficiently distinctive that a diagnosis of gold-associated lymphadenopathy could be rendered. A review of the literature revealed no descriptions of the light microscopic appearance of gold in lymph nodes. In this case, the diagnosis of gold-associated lymphadenopathy was confirmed by scanning electron microscopic studies.
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Affiliation(s)
- S D Rollins
- Department of Pathology, St. Louis University School of Medicine, Mo
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36
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Craig JP. Academy requirements questioned. Bull Med Libr Assoc 1990; 78:72-3. [PMID: 2295020 PMCID: PMC225341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Craig JP. Secretory carcinoma of the breast in an adult. Correlation of aspiration cytology and histology on the biopsy specimen. Acta Cytol 1985; 29:589-92. [PMID: 3861051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Needle aspiration was performed on the excisional biopsy specimen of a breast mass in a 63-year-old woman. The cytologic features in the aspirate included solid and papillary proliferations of tumor cells with abundant intracytoplasmic vacuolization and secretion. Histologic study of the lesion showed a secretory carcinoma. Although this is a rare breast neoplasm, especially in adults, the cellular features are characteristic and may permit a specific diagnosis on needle aspirates.
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Yamamoto K, Takeda Y, Miwatani T, Craig JP. Evidence that a non-O1 Vibrio cholerae produces enterotoxin that is similar but not identical to cholera enterotoxin. Infect Immun 1983; 41:896-901. [PMID: 6411622 PMCID: PMC264585 DOI: 10.1128/iai.41.3.896-901.1983] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Cholera-like enterotoxin produced by a non-O1 strain of Vibrio cholerae, S7 (S7 enterotoxin), isolated from human diarrheal stool, was purified, and its physicochemical, biological, and immunological properties were compared with those of cholera enterotoxin from V. cholerae O1 569B (CT) and an enterotoxin produced by another non-O1 V. cholerae (E8498 enterotoxin) reported previously (Yamamoto et al., Infect. Immun. 39:1128-1135, 1983). The purified S7 enterotoxin had physicochemical properties different from those of CT and E8498 enterotoxin. S7 enterotoxin had greater relative mobility in conventional polyacrylamide gel disc electrophoresis and a lower isoelectric point, and its B subunit was smaller than those of CT and E8498 enterotoxin. The results of sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis suggested that the size of the aggregate of the B subunits of S7 enterotoxin is larger than that of CT and E8498 enterotoxin. The biological and immunological properties of S7 enterotoxin were indistinguishable from those of CT and E8498 enterotoxin. These results indicate that non-O1 vibrios may produce more than one kind of cholera-like enterotoxin: one which is identical to CT (E8498 enterotoxin type) and another which is not identical to CT (S7 enterotoxin type).
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Pierce NF, Cray WC, Sacci JB, Craig JP, Germanier R, Fürer E. Oral immunization against experimental cholera: the role of antigen form and antigen combinations in evoking protection. Ann N Y Acad Sci 1983; 409:724-33. [PMID: 6603186 DOI: 10.1111/j.1749-6632.1983.tb26911.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Pierce NF, Cray WC, Sacci JB, Craig JP, Germanier R, Fürer E. Procholeragenoid: a safe and effective antigen for oral immunization against experimental cholera. Infect Immun 1983; 40:1112-8. [PMID: 6602094 PMCID: PMC348165 DOI: 10.1128/iai.40.3.1112-1118.1983] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The immunogenicity and safety of procholeragenoid, a minimally toxic, heat-induced aggregate of cholera toxin (CT), were studied in enterically immunized rats and dogs. Although 99% less toxic than CT, procholeragenoid was only slightly less efficient in causing jejunal anti-CT responses in rats; in contrast, choleragenoid, the nontoxic B subunit pentamer of CT, was much less effective. The immunogenicity of procholeragenoid was due almost entirely to its large-molecular-weight components (MW = 10(6) to 10(7)) and was markedly reduced by preincubation with GM1 ganglioside or treatment with Formalin to eliminate residual toxicity. These findings suggest that molecular aggregation, binding to GM1 receptors on cell membranes, and stimulation of cellular adenylate cyclase each contributed to the effectiveness of procholeragenoid as a mucosal immunogen. In dogs, oral immunization with five 500-micrograms doses of procholeragenoid evoked vigorous anti-CT responses in jejunal mucosa without causing significant diarrhea. When subsequently challenged with virulent Vibrio cholerae, immunized dogs showed 83% protection against the development of severe or lethal diarrhea compared with non-immunized controls. These results confirm a protective role for mucosal antitoxin in experimental cholera and show that procholeragenoid is both safe and effective as an oral immunogen. Procholeragenoid, combined with other antigens of V. cholerae, may constitute a simple, safe, and effective oral vaccine for cholera.
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Yamamoto K, Takeda Y, Miwatani T, Craig JP. Purification and some properties of a non-o1 Vibrio cholerae enterotoxin that is identical to cholera enterotoxin. Infect Immun 1983; 39:1128-35. [PMID: 6188694 PMCID: PMC348073 DOI: 10.1128/iai.39.3.1128-1135.1983] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Cholera-like enterotoxin was isolated and purified from the culture supernatant of a non-O1 strain of Vibrio cholerae, E8498, isolated from the environment. Enterotoxin was purified by aluminum hydroxide absorption and elution and successive gel filtrations on Sephadex G-100, Bio-Gel A-5m, and Sephadex G-75. Purified enterotoxin gave a single stained band on polyacrylamide gel disc electrophoresis, and the mobility was the same as that of cholera enterotoxin. The specific biological activity of the purified enterotoxin was almost the same as that of cholera enterotoxin in the Chinese hamster ovary cell assay, fluid accumulation in mouse ligated intestine, increase in vascular permeability in rabbit skin, and passive immune hemolysis. Sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis showed that the purified enterotoxin consisted of subunits A and B, identical to those of cholera enterotoxin, and Ouchterlony double gel diffusion tests indicated that the two toxins were immunologically identical. Enterotoxins prepared from several non-O1 strains isolated from human patients were also immunologically identical to cholera enterotoxin.
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Abstract
We report on a patient with von Hippel-Lindau disease. Exploration revealed 15 solid tumors and 18 cysts filled with clear fluid throughout both kidneys. All solid tumors consisted of clear cells consistent with renal cell carcinoma. All cysts were lined with similar clear cells. The solid tumors contained areas of clear cells surrounding small cystic spaces and the large cysts appeared to be an exaggeration of this phenomenon. There is a place for radical ablative surgery in patients with multiple renal cell carcinomas in von Hippel-Landau disease. Unroofing and gross examination of apparently simple cysts may not be adequate to rule out the presence of carcinoma in these patients.
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Clements ML, Levine MM, Young CR, Black RE, Lim YL, Robins-Browne RM, Craig JP. Magnitude, kinetics, and duration of vibriocidal antibody responses in North Americans after ingestion of Vibrio cholerae. J Infect Dis 1982; 145:465-73. [PMID: 7069227 DOI: 10.1093/infdis/145.4.465] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Sera from 147 volunteers were examined for vibriocidal antibody by the tube-dilution method before and after they ingested 10(3)-10(6) Vibrio cholerae organisms. Titers increased significantly after challenge in 97% of 110 persons who excreted V. cholerae. In 12% of the bacteriologically confirmed infections, the titer increased significantly only to the homologous (Inaba or Ogawa) serotype. Levels of vibriocidal antibody decreased substantially between one and six months after challenge, but they usually remained elevated over base-line values. Levels of antitoxin to V. cholerae were measured by IgG enzyme-linked immunosorbent assay (ELISA), rabbit skin permeability tests, and adrenal cell techniques in 73 pairs of prechallenge and postchallenge sera. Results of the vibriocidal assay agreed most closely with those of the ELISA, the most sensitive antitoxin assay, in serologically detecting clinical and subclinical infections. Recent infection could be accurately serodiagnosed by levels of vibriocidal antibody and antitoxin (by IgG ELISA) in a convalescent-phase serum.
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Levine MM, Black RE, Clements ML, Cisneros L, Saah A, Nalin DR, Gill DM, Craig JP, Young CR, Ristaino P. The pathogenicity of nonenterotoxigenic Vibrio cholerae serogroup O1 biotype El Tor isolated from sewage water in Brazil. J Infect Dis 1982; 145:296-9. [PMID: 7061878 DOI: 10.1093/infdis/145.3.296] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Nonenterotoxigenic strains no. 1196-78 and no. 1074-78 of Vibrio cholerae serogroup O1 (biotype El Tor, serotype Ogawa) were isolated from sewage water in Brazil and fed to 20 volunteers. Neither strain caused diarrhea. None of the seven volunteers who ingested Ogawa strain no. 1074-78 (10(6) organisms) excreted the organism whereas eight of the 13 volunteers who ingested Ogawa strain no. 1196-78 (10(6) or 10(8) organisms) did excrete the organism in their stools. None of 114 stool-culture isolates yielded cholera enterotoxin, and none of the 20 volunteers had significant increases in serum titers of antitoxin as measured by enzyme-linked immunosorbent assay although six of the volunteers had slightly elevated vibriocidal antibody levels. Six volunteers used as controls and four volunteers who had stool cultures positive for strain no. 1196-78 of V. cholerae were challenged with pathogenic El Tor Ogawa strain no. E7946 (10(6) organisms) to determine if previous ingestion of the Brazilian strain would induce protective immunity. All 10 of the volunteers developed diarrhea, and the severity of the illness was similar in both groups.
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Craig JP, Yamamoto K, Takeda Y, Miwatani T. Production of cholera-like enterotoxin by a Vibrio cholerae non-O1 strain isolated from the environment. Infect Immun 1981; 34:90-7. [PMID: 7298194 PMCID: PMC350825 DOI: 10.1128/iai.34.1.90-97.1981] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Vibrio cholerae non-O1 strain E8498, isolated in 1978 from fresh water in Louisiana, produced a vascular permeability factor when cultured in shallow resting cultures of Casamino Acids-yeast extract-glucose medium for 24 h at 30 degrees C. Undiluted resting culture filtrates contained heat-labile permeability factor activity which was only partially neutralized by cholera antitoxin and GM1 ganglioside. Supernatants concentrated with PM-10 membranes caused hemorrhage and necrosis in rabbits within 1 h after intracutaneous injection, whereas appropriate dilutions of both filtrates and concentrates demonstrated delayed permeability factor activity, without hemorrhage or necrosis, which was indistinguishable in appearance from that caused by purified cholera enterotoxin produced by V. cholerae O1 Inaba strain 569B. Crude E8498 filtrates contained the biological equivalent of about 5 ng/ml of purified enterotoxin. Permeability factor activity in the fraction obtained by 20 to 50% saturation of filtrate concentrate with ammonium sulfate could be completely neutralized by reference standard cholera antitoxin prepared against purified 569 B enterotoxin. Hemorrhagic activity was unaffected by cholera antitoxin. A 5,000-fold concentrate of the culture supernatant yielded a line of identity with purified cholera enterotoxin in an agar gel double-diffusion test against cholera antitoxin purified by affinity column chromatography with BrCN-activated Sepharose 4B-linked purified cholera enterotoxin as the adsorbent. These findings indicate that V. cholerae non-O1 E8498 produces a permeability factor which is immunologically and biologically indistinguishable from that produced by a strain of V. cholerae O1 classical biotype.
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Abstract
Purified heat-stable enterotoxin (ST) prepared from supernatants of Escherichia coli strain 53402 A-1, isolated from a patient with diarrhea, caused an increase in the permeability of the small blood vessels of the skin of adult rabbits after intracutaneous injection. Increased permeability was manifested by localized accumulation of intravenously injected blue dye at the injection sites. Permeability factor (PF) activity reached a peak 1 h after injection, and recovery of normal permeability was nearly complete in 3 h. Residual PF activity had disappeared by 24 h. Dose-response curves demonstrated a straight-line relationship between the logarithm of the dose and mean blueing diameter over a range of 3 to 12 mm. The PF assay was less sensitive that the suckling mouse assay, and adult rabbits varied in their sensitivity to the PF effect. Five to 100 mouse units of ST were required to consistently evoke strong and unequivocal blue lesions of 7 mm or more in diameter. PF activity was reduced 50 to 70% by heating at 70 degrees C for 30 min, 60 to 80% by boiling for 30 min, and 95 to 98% by autoclaving for 15 min, but it was unaffected by treatment with cholera antitoxin. These findings are consistent with the notion that PF activity is a property of the ST molecule itself. This PF assay cannot be used for the detection of ST in crude culture supernatant fluid because of low sensitivity and the presence of nonspecific PF effects of culture media and other E. coli products.
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Snyder JD, Allegra DT, Levine MM, Craig JP, Feeley JC, DeWitt WE, Blake PA. Serologic studies of naturally acquired infection with Vibrio cholerae serogroup O1 in the United States. J Infect Dis 1981; 143:182-7. [PMID: 7194358 DOI: 10.1093/infdis/143.2.182] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The discovery of 11 persons infected with Vibrio cholerae serogroup O1 (biotype El Tor, serotype Inaba) in southwestern Louisiana in 1978 provided an opportunity to evaluate the serologic response to this agent in North Americans with naturally acquired infection. One antibacterial assay (vibriocidal assay) and two antitoxin assays (enzyme linked immunosorbent assays [ELISA] and rabbit skin permeability factor assay) were used. Antitoxin levels were elevated longer than vibriocidal antibody levels, and asymptomatic infected persons had levels of antitoxin and vibriocidal antibody levels, and asymptomatic infected persons had levels of antitoxin and vibriocidal antibody as high as those of persons with clinical cholera. With use of serologic criteria derived from these studies, one additional person infected with V. cholerae O1 was discovered, and a relatively low (4%-7%) prevalence rate of elevated levels of vibriocidal antibody and antitoxin was found in a serum survey of a community with several known cases. Comparison of the results from the ELISA and the rabbit skin permeability factor assay demonstrated similar rates of elevated levels of antitoxin, but the ELISA required less time and less serum per sample analyzed.
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Blake PA, Allegra DT, Snyder JD, Barrett TJ, McFarland L, Caraway CT, Feeley JC, Craig JP, Lee JV, Puhr ND, Feldman RA. Cholera--a possible endemic focus in the United States. N Engl J Med 1980; 302:305-9. [PMID: 7350497 DOI: 10.1056/nejm198002073020601] [Citation(s) in RCA: 216] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In September and October 1978, after a case of cholera had been discovered in southwestern Louisiana, 10 more Vibrio cholerae O-Group 1 infections were detected in four additional clusters. All 11 infected persons had recently eaten cooked crabs from five widely separated sites in the coastal marsh, and a matched-triplet case-control study showed a significant relation between cholera and eating such crabs (P = 0.007). V. cholerae O1 was isolated from estuarine water, from fresh shrimp, from a leftover cooked crab from a patient's refrigerator, and from sewage in six towns, including three without identified cases. All isolates in Louisiana and an isolate from a single unexplained case in Texas in 1973 were biotype El Tor and serotype inaba; they were hemolytic and of a phage type unique to the United States--suggesting that the organism persisted undetected along the Gulf Coast for at least five years.
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Young CR, Levine MM, Craig JP, Robins-Browne R. Microtiter enzyme-linked immunosorbent assay for immunoglobulin G cholera antitoxin in humans: method and correlation with rabbit skin vascular permeability factor technique. Infect Immun 1980; 27:492-6. [PMID: 7189746 PMCID: PMC550792 DOI: 10.1128/iai.27.2.492-496.1980] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A microtiter enzyme-linked immunosorbent assay (ELISA) to measure immunoglobulin G cholera antitoxin in human serum has been developed. The ELISA employs commercially available reagents, including cholera enterotoxin and goat anti-human immunoglobulin G. It is specific, sensitive, and reproducible and requires as little as 5 microliter of serum. ELISA, moreover, permits quantitative determination of cholera antitoxin at a single serum dilution of 1:200. A total of 162 pre- and post-challenge sera from 49 volunteers who ingested Vibrio cholerae classical biotype, and 165 sera from 43 volunteers who ingested V. cholerae El Tor biotype, were tested for cholera antitoxin by ELISA and by the rabbit skin vascular permeability factor assay. The correlation between the two assays was statistically significant (P less than 0.001). ELISA for immunoglobulin G cholera antitoxin thus provides a valuable in vitro correlate of in vivo toxin-neutralizing capacity. Microtiter ELISA permits duplicate evaluation of at least 14 sera per 96-well plate including blanks and controls, is readily adapted to use in field studies, and therefore is particularly well suited to seroepidemiological surveys.
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Abstract
Selected rabbit antisera to cholera toxin antigens and convalescent cholera patient sera were analyzed using the permeability factor neutralization test and two sensitive in vitro serological assays specific for cholera toxin, cholera toxin A subunit, and cholera toxin B subunit. The results indicated that antisera to cholera toxin contained toxin-neutralizing activity as well as antibodies specific for both the A subunit and B subunit. It was clearly established that antisera to B subunit, devoid of significant anti-A subunit activity, neutralized the vascular permeability activity of cholera toxin. Antisera to A subunit contained neutralizing antibodies and antibodies to both A and B subunits. Absorption with B subunit removed both the toxin-neutralizing and anti-B subunit activities, while the anti-A activity was unaffected. Neutralizing antibody titers of rabbits immunized with B subunit were also observed to be significantly higher than neutralizing antibody titers of sera from A subunit-immunized rabbits, despite the overall similarity in anti-B subunit titers as determined by passive hemagglutination and radioimmunoassay of sera from the two groups of rabbits. Anti-alpha chain sera neither neutralized cholera toxin nor possessed significant antitoxin or anti-B subunit titers as determined by passive hemagglutination and radioimmunoassay. The anti-alpha chain sera contained high levels of antibody specific for A subunit, which is consistent with the hypothesis that the alpha chain is part of the A subunit structure. In contrast, the gamma chain was not shown to be antigenic. Sera from convalescent cholera patients possessed toxin-neutralizing antibody as well as passive hemagglutination and radioimmunoassay antibody against both A and B subunits.
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