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Mudau MM, Dillon B, Smal C, Feben C, Honey E, Carstens N, Krause A. Mutation analysis and clinical profile of South African patients with Neurofibromatosis type 1 (NF1) phenotype. Front Genet 2024; 15:1331278. [PMID: 38596211 PMCID: PMC11002079 DOI: 10.3389/fgene.2024.1331278] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 03/11/2024] [Indexed: 04/11/2024] Open
Abstract
Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic condition with complete age-dependent penetrance, variable expressivity and a global prevalence of ∼1/3,000. It is characteriszed by numerous café-au-lait macules, skin freckling in the inguinal or axillary regions, Lisch nodules of the iris, optic gliomas, neurofibromas, and tumour predisposition. The diagnostic testing strategy for NF1 includes testing for DNA single nucleotide variants (SNVs), copy number variants (CNVs) as well as RNA analysis for deep intronic and splice variants, which can cumulatively identify the causative variant in 95% of patients. In the present study, NF1 patients were screened using a next-generation sequencing (NGS) assay targeting NF1 exons and intron/exon boundaries for SNV and NF1 multiple ligation-dependent probe amplification (MLPA) analysis for CNV detection. Twenty-six unrelated Southern African patients clinically suspected of having NF1, based on the clinical diagnostic criteria developed by the National Institute of Health (NIH), were included in the current study. A detection rate of 58% (15/26) was obtained, with SNVs identified in 80% (12/15) using a targeted gene panel and NF1 gene deletion in 20% (3/15) identified using MLPA. Ten patients (38%) had no variants identified, although they met NF1 diagnostic criteria. One VUS was identified in this study in a patient that met NF1 diagnostic criteria, however there was no sufficient information to classify variant as pathogenic. The clinical features of Southern African patients with NF1 are similar to that of the known NF1 phenotype, with the exception of a lower frequency of plexiform neurofibromas and a higher frequency of developmental/intellectual disability compared to other cohorts. This is the first clinical and molecular characterisation of a Southern African ancestry NF1 cohort using both next-generation sequencing and MLPA analysis. A significant number of patients remained without a diagnosis following DNA-level testing. The current study offers a potential molecular testing strategy for our low resource environment that could benefit a significant proportion of patients who previously only received a clinical diagnosis without molecular confirmation.
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Affiliation(s)
- Maria Mabyalwa Mudau
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Bronwyn Dillon
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Clarice Smal
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Candice Feben
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Engela Honey
- Department of Biochemistry, Genetics and Microbiology, Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Nadia Carstens
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
| | - Amanda Krause
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Campbell L, Fredericks J, Mathivha K, Moshesh P, Coovadia A, Chirwa P, Dillon B, Ghoor A, Lawrence D, Nair L, Mabaso N, Mokwele D, Novellie M, Krause A, Carstens N. The implementation and utility of clinical exome sequencing in a South African infant cohort. Front Genet 2023; 14:1277948. [PMID: 38028619 PMCID: PMC10665497 DOI: 10.3389/fgene.2023.1277948] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Genetic disorders are significant contributors to infant hospitalization and mortality globally. The early diagnosis of these conditions in infants remains a considerable challenge. Clinical exome sequencing (CES) has shown to be a successful tool for the early diagnosis of genetic conditions, however, its utility in African infant populations has not been investigated. The impact of the under-representation of African genomic data, the cost of testing, and genomic workforce shortages, need to be investigated and evidence-based implementation strategies accounting for locally available genetics expertise and diagnostic infrastructure need to be developed. We evaluated the diagnostic utility of singleton CES in a cohort of 32 ill, South African infants from two State hospitals in Johannesburg, South Africa. We analysed the data using a series of filtering approaches, including a curated virtual gene panel consisting of genes implicated in neonatal-and early childhood-onset conditions and genes with known founder and common variants in African populations. We reported a diagnostic yield of 22% and identified seven pathogenic variants in the NPHS1, COL2A1, OCRL, SHOC2, TPRV4, MTM1 and STAC3 genes. This study demonstrates the utility value of CES in the South African State healthcare setting, providing a diagnosis to patients who would otherwise not receive one and allowing for directed management. We anticipate an increase in the diagnostic yield of our workflow with further refinement of the study inclusion criteria. This study highlights important considerations for the implementation of genomic medicine in under-resourced settings and in under-represented African populations where variant interpretation remains a challenge.
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Affiliation(s)
- L. Campbell
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - J. Fredericks
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - K. Mathivha
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Moshesh
- Department of Paediatrics and Child Health, School of Clinical Medicine, Nelson Mandela Children’s Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Coovadia
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - P. Chirwa
- Nelson Mandela Children’s Hospital, Johannesburg, South Africa
| | - B. Dillon
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Ghoor
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Lawrence
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - L. Nair
- Department of Paediatrics and Child Health, School of Clinical Medicine, Rahima Moosa Mother and Child Hospital, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Mabaso
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - D. Mokwele
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - M. Novellie
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - A. Krause
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - N. Carstens
- Division of Human Genetics, National Health Laboratory Service andSchool of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Genomics Platform, South African Medical Research Council, Cape Town, South Africa
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3
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Dillon B, Feben C, Segal D, du Plessis J, Reynders D, Wainwright R, Poole J, Krause A. Endocrine profiling in patients with Fanconi anemia, homozygous for a FANCG founder mutation. Mol Genet Genomic Med 2020; 8:e1351. [PMID: 32529760 PMCID: PMC7434606 DOI: 10.1002/mgg3.1351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Fanconi anemia (FA) is phenotypically diverse, hereditary condition associated with bone marrow failure, multiple physical abnormalities, and an increased susceptibility to the development of malignancies. Less recognized manifestations of FA include endocrine abnormalities. International discourse has highlighted that these abnormalities are widespread among children and adults with FA. To date there has been no systematic study that has evaluated the endocrine abnormalities in a cohort of patients with FA, homozygous for a founder mutation (c.637_643del (p.Tyr213Lysfs*6)) in FANCG. The objectives of the study were to evaluate endocrine gland function in patients with FA of a single FA genotype, and to determine the frequency and nature of endocrine abnormalities in this group. METHODS Cross-sectional, descriptive study of 24 South African patients of African ancestry with FA (homozygous for a FANCG founder mutation). Outcomes measured included growth, pubertal status, growth hormone axis screening, thyroid gland function, glucose and insulin metabolism and bone age (BA). RESULTS Endocrine dysfunction was present in 70.8% (17 of 24), including abnormal insulin-like growth factor 1 (IGF-1)/insulin-like growth factor-binding protein 3 (IGFBP-3) in 25.0% (6 of 24), insulin resistance in 41.7% (10 of 24), abnormal thyroid function in 16.7% (4 of 24) and short stature in 45.8% (11 of 24). No abnormalities of glucose metabolism were identified. Abnormal pubertal status was seen in three males (12.5%). Abnormal BAs were present in 34.8% (8 of 23). CONCLUSION Endocrine abnormalities occur at a high frequency in patients with FA, homozygous for a FANCG founder mutation, similar to other FA cohorts. Our data are specific to FA patients with a single genotype, and therefore provide the first genotype-phenotype information on endocrine abnormalities in South African patients, homozygous for a FANCG founder mutation. Recommendations regarding endocrine screening in this patient subgroup are made, including, but not limited to, baseline testing of thyroid function, fasted insulin and glucose, and IGF-1 and IGFBP-3.
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Affiliation(s)
- Bronwyn Dillon
- Division of Human GeneticsNational Health Laboratory Service and School of PathologyFaculty of Health SciencesThe University of the WitwatersrandJohannesburgGautengSouth Africa
| | - Candice Feben
- Division of Human GeneticsNational Health Laboratory Service and School of PathologyFaculty of Health SciencesThe University of the WitwatersrandJohannesburgGautengSouth Africa
| | - David Segal
- The University of the Witwatersrand and The Wits University Donald Gordon Medical CentreJohannesburgGautengSouth Africa
| | - Johannes du Plessis
- Paediatric Oncology UnitUniversitas Hospital and The University of the Free StateBloemfonteinFree StateSouth Africa
| | - David Reynders
- Paediatric Haematology and Oncology UnitSteve Biko Academic Hospital and The University of PretoriaPretoriaGautengSouth Africa
| | - Rosalind Wainwright
- Department of Paediatric Haematology and OncologyChris Hani Baragwanath Academic Hospital and The University of the WitwatersrandJohannesburgGautengSouth Africa
| | - Janet Poole
- Department of Paediatric Haematology and OncologyCharlotte Maxeke Johannesburg Academic Hospital and The University of the WitwatersrandJohannesburgGautengSouth Africa
| | - Amanda Krause
- Division of Human GeneticsNational Health Laboratory Service and School of PathologyFaculty of Health SciencesThe University of the WitwatersrandJohannesburgGautengSouth Africa
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Shaikh R, Alomari A, Dillon B. Cryoablation: an effective tool in treatment of refractory pain in fibro adipose vascular anomaly. J Vasc Interv Radiol 2015. [DOI: 10.1016/j.jvir.2014.12.552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Shaikh R, Alomari A, Chaudry G, Dillon B, Orbach D, Padua H. Outcome of endovascular treatment for aneurysmal bone cysts. J Vasc Interv Radiol 2013. [DOI: 10.1016/j.jvir.2013.01.480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Shaikh R, Chaudry G, Dillon B, Padua H, Alomari A. Abstract No. 266: Embolization of the dominant draining veins: an effective approach for arteriovenous malformations. J Vasc Interv Radiol 2012. [DOI: 10.1016/j.jvir.2011.12.319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Khawaldeh A, Morales S, Dillon B, Alavidze Z, Ginn AN, Thomas L, Chapman SJ, Dublanchet A, Smithyman A, Iredell JR. Bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection. J Med Microbiol 2011; 60:1697-1700. [PMID: 21737541 DOI: 10.1099/jmm.0.029744-0] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We describe the success of adjunctive bacteriophage therapy for refractory Pseudomonas aeruginosa urinary tract infection in the context of bilateral ureteric stents and bladder ulceration, after repeated failure of antibiotics alone. No bacteriophage-resistant bacteria arose, and the kinetics of bacteriophage and bacteria in urine suggest self-sustaining and self-limiting infection.
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Affiliation(s)
- A Khawaldeh
- Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
| | - S Morales
- Special Phage Services Pty, Brookvale, Sydney, NSW, Australia
| | - B Dillon
- Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
| | - Z Alavidze
- Eliava Institute of Bacteriophage, Microbiology and Virology, Georgian Academy of Sciences, Tbilisi, Democratic Republic of Georgia
| | - A N Ginn
- Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
| | - L Thomas
- Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
| | - S J Chapman
- Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
| | - A Dublanchet
- GEEPhage, CHI Villeneuve St Georges, Villeneuve St Georges, France
| | - A Smithyman
- Special Phage Services Pty, Brookvale, Sydney, NSW, Australia
| | - J R Iredell
- Sydney Institute for Emerging Infection and Biotechnology, University of Sydney at Westmead Hospital, NSW 2145, Australia.,Centre for Infectious Diseases and Microbiology, Sydney West Area Health Service, NSW 2145, Australia
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Abstract
SUMMARY The suitability of alternative sites for non-invasive blood pressure (NIBP) measurement was investigated in 100 awake healthy volunteers. The calf and the ankle were chosen for comparison with the arm, and the results analysed subjected to Bland-Altman analysis. Discomfort was graded using a Visual Analogue Scale. There was a poor agreement between the different sites with respect to systolic blood pressure: the agreement was closer for diastolic and mean measurements. The mean blood pressure calf measurement was on average 4 mmHg (95% limits of agreement -12 to 20), higher than the arm. The ankle was 8 mmHg higher (-8 to 24) than the arm. ANOVA demonstrated a statistically significant difference in the discomfort scores between the sites (p < 0.001). The calf demonstrated the highest discomfort score and the ankle the lowest. We suggest that the ankle should be considered in preference to the calf as an alternative site for NIBP measurement if use of an arm is undesirable or impossible.
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Affiliation(s)
- C Moore
- Department of Medical statistics, South Manchester University Hospitals NHS Trust, Wythrnshawe, Manchester, UK
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Mercy J, Dillon B, Morris J, Emmerson AJ, Mughal MZ. Relationship of tibial speed of sound and lower limb length to nutrient intake in preterm infants. Arch Dis Child Fetal Neonatal Ed 2007; 92:F381-5. [PMID: 17369280 PMCID: PMC2675363 DOI: 10.1136/adc.2006.105742] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Metabolic bone disease of prematurity is characterised by impaired postnatal mineralisation of the rapidly growing infant skeleton. OBJECTIVE To longitudinally evaluate postnatal changes in tibial speed of sound (tSOS; which reflects cortical thickness and bone mineral density) and lower limb length (LLL; a measure of tibial growth) in very low birthweight preterm infants receiving contemporary neonatal care. METHODS tSOS and LLL were measured using a quantitative ultrasound device and an electronic neonatal knemometer, respectively, in the same limb, weekly, for a median period of four weeks (3-16 weeks) in 84 preterm infants (median gestation 26.8 weeks (range 23-35.2 weeks) and median birth weight 869.5 g (range 418-1481 g)). RESULTS Initial tSOS and LLL were correlated with gestation (r = 0.42, p<0.001; r = 0.76, p<0.001, respectively) and birth weight (r = 0.23, p = 0.038; r = 0.93, p<0.001, respectively). Postnatally, tSOS decreased (r = -0.15, p = 0.011) whereas LLL increased (r = 0.96, p<0.001) with age. The rate of postnatal change in LLL, but not in tSOS, was positively influenced by intake of calcium (p = 0.03), phosphorus (p = 0.01) and vitamin D (p = 0.03). CONCLUSIONS The postnatal decline in tSOS, which is probably due to cortical thinning secondary to endocortical bone loss, and increase in LLL provide new insight into the development of long bones in preterm infants.
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Affiliation(s)
- J Mercy
- Department of Paediatric Medicine, St Mary's Hospital for Women & Children, Hathersage Road, Manchester M13 0JH, England.
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10
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Howcroft DWJ, Fehily MJ, Peck C, Fox A, Dillon B, Johnson DS. The role of preoperative templating in total knee arthroplasty: comparison of three prostheses. Knee 2006; 13:427-9. [PMID: 17029816 DOI: 10.1016/j.knee.2006.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 05/08/2006] [Accepted: 05/11/2006] [Indexed: 02/02/2023]
Abstract
Templating of preoperative radiographs is routinely recommended prior to knee arthroplasty. We performed this study to assess the reproducibility and accuracy of the templates for three commonly used knee implants (PFC, Kinemax, Scorpio). Six lower limb surgeons templated 10 patients for each of the three designs. The inter- and intra-observer reliability and accuracy was calculated. There was marked variation in the reliability of the templating with the tibial insert scoring better than the femoral and the Kinemax being the most reproducible of the three. In general, the intra-observer scores (kappa=0.57-0.81) were better than the inter-observer ones (kappa=0.21-0.60). The Scorpio was the most accurately templated of the three implants, with the percentage correlating with what was actually implanted ranging from 55% to 62% for the femur and 72% to 75% for the tibia, with no templated sizes more than one size different from the actual implant. The other implants ranged from 38% to 42% for the femur and 53% to 58% for the tibia with both having up to 3% more than 1 size difference from the actual implant. We believe that the use of templating in total knee arthroplasty should be interpreted with caution and we urge the development of more accurate prosthesis sizing techniques.
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Affiliation(s)
- D W J Howcroft
- Stockport NHS Foundation Trust, Stepping Hill Hospital, Poplar Grove, Stockport, SK2 7JE, UK
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Bunnell RE, Nassozi J, Marum E, Mubangizi J, Malamba S, Dillon B, Kalule J, Bahizi J, Musoke N, Mermin JH. Living with discordance: knowledge, challenges, and prevention strategies of HIV-discordant couples in Uganda. AIDS Care 2006; 17:999-1012. [PMID: 16176896 DOI: 10.1080/09540120500100718] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [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: 10/25/2022]
Abstract
Prevalence of HIV-discordance among couples in sub-Saharan Africa is high. Negative partners are at high risk of HIV infection but few HIV/AIDS service providers have developed effective counseling messages for HIV-discordant couples. To identify clients' explanations for discordance, challenges, and prevention strategies, 24 in-depth interviews and 4 focus group discussions were conducted with 32 female and 35 male members of HIV-discordant couples who sought HIV voluntary counseling and testing (VCT) in Uganda. In addition, counselor explanations for discordance were gathered from 62 counselor trainers during 3 interactive workshops. Misconceptions about discordance were widespread among clients and counselors. Common explanations included: the concept of a hidden infection not detectable by HIV tests, belief in immunity, the thought that gentle sex protected HIV-negative partners, and belief in protection by God. Such explanations for discordance reinforced denial of HIV risk for the negative partner within discordant couples and potentially increased transmission risk. Couples identified negotiation of sexual relations as their most formidable challenge. Prevention strategies included condom use, abstinence and separation of beds, contractual agreements for outside sexual partners, and relationship cessation. Discordant couples represent a critical risk group and improved counseling protocols that clearly explain discordance, emphasize high risk of transmission, and support risk reduction are urgently needed.
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Affiliation(s)
- R E Bunnell
- CDC-Uganda, Uganda Virus Research Institute, Entebbe, Uganda.
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12
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Dillon B, Thomas L, Mohmand G, Zelynski A, Iredell J. Multiplex PCR for screening of integrons in bacterial lysates. J Microbiol Methods 2005; 62:221-32. [PMID: 16009279 DOI: 10.1016/j.mimet.2005.02.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2004] [Revised: 01/21/2005] [Accepted: 02/15/2005] [Indexed: 11/26/2022]
Abstract
Bacterial integrons are a useful PCR amplification target in epidemiological surveys of bacterial antibiotic resistance, and a variety of primers have been published. We describe multiplex PCR methodology to test for classes 1, 2 and 3 integron-associated integrases in boiled lysates of Gram-negative bacteria. We report on performance in Acinetobacter spp. (n=50), Enterobacteriaceae (n=76), Pseudomonas aeruginosa (n=15), Bacteroidesspp. (n=69), and in undifferentiated mixed cultures derived from perineal swabs (n=50) and endotracheal aspirates (n=8). This method achieved 100% sensitivity and specificity in simple lysates made from a range of bacteria, without requiring DNA extraction, and is recommended as an efficient screening tool for surveys of integron cassettes.
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Affiliation(s)
- B Dillon
- Centre for Infectious Diseases and Microbiology, University of Sydney, Australia
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13
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Affiliation(s)
- B Dillon
- Centre for Infectious Diseases and Microbiology, University of Sydney, Westmead Hospital, NSW 2145, Australia
| | - J Iredell
- Centre for Infectious Diseases and Microbiology, University of Sydney, Westmead Hospital, NSW 2145, Australia
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14
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Dillon B, Valenzuela J, Don R, Blanckenberg D, Wigney DI, Malik R, Morris AJ, Robson JM, Iredell J. Limited diversity among human isolates of Bartonella henselae. J Clin Microbiol 2002; 40:4691-9. [PMID: 12454174 PMCID: PMC154592 DOI: 10.1128/jcm.40.12.4691-4699.2002] [Citation(s) in RCA: 37] [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: 11/20/2022] Open
Abstract
A study of 59 isolates of Bartonella henselae reveals relatively limited diversity among those of human origin (n = 28). Either of two distinct alleles of both gltA and 16S ribosomal DNA (rDNA) was found in all isolates, with a high level of congruity between 16S and gltA inheritance among proven human pathogens. Human isolates from all over Eastern Australia were most commonly 16S rDNA (Bergmans) type I, with the same gltA allele as the type strain (Houston-1). Comparable feline isolates were more commonly 16S type II, with less congruity of inheritance between 16S and gltA alleles. Previously described arbitrarily primed PCR and EagI-HhaI infrequent restriction site PCR fingerprinting techniques separated Bartonella species effectively but lacked discriminating power within B. henselae. Examination of the 16-23S intergenic spacer region revealed for several strains several point mutations as well as a repeat sequence of unknown significance which is readily detected by HaeIII restriction fragment length polymorphism analysis. The bacteriophage-associated papA gene was present in all isolates. Enterobacterial repetitive intergenic consensus PCR proved to be a useful and robust typing tool and clearly separated human isolates (including imported strains) from the majority of feline isolates. Our data are consistent with published evidence and with previous suggestions of intragenomic rearrangements in the type strain and suggest that human isolates come from a limited subset of B. henselae strains. They strengthen arguments for careful exploration of genotype-phenotype relationships and for the development of a multilocus enzyme electrophoresis and multilocus sequence typing-based approach to the phylogeny of B. henselae.
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Affiliation(s)
- B. Dillon
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - J. Valenzuela
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - R. Don
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - D. Blanckenberg
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - D. I. Wigney
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - R. Malik
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - A. J. Morris
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - J. M. Robson
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
| | - J. Iredell
- Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, New South Wales 2145, Faculty of Veterinary Science, University of Sydney, New South Wales 2006, Sullivan and Nicolaides Pathology, Taringa, Queensland 4068, Australia, Department of Microbiology, Green Lane Hospital, Auckland 1003, New Zealand
- Corresponding author. Mailing address: Centre for Infectious Diseases and Microbiology, Westmead Hospital, University of Sydney, NSW 2145, Australia. Phone: 61 2 9845 6255. Fax: 61 2 9891 5317. E-mail:
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Dillon B, Cagney M, Manolios N, Iredell JR. Failure to detect Bartonella henselae infection in synovial fluid from sufferers of chronic arthritis. Rheumatol Int 2001; 19:219-22. [PMID: 11063291 DOI: 10.1007/pl00006854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 10/24/2022]
Abstract
Bartonella henselae causes granulomatous and indolent infection in the immune competent human, and angioproliferation in the context of persistent infection and impaired immunity. This bacterium is found in up to 40% of household cats, from which humans acquire it by either a cat scratch or a bite (hence the name, cat-scratch disease). Approximately 5% of Australian and US blood donors have serological evidence of past infection, but most associated illnesses are mild or subclinical. A number of lines of evidence prompted us to consider a relationship between rheumatoid arthritis (RA) and Bartonella infection. These include epidemiological associations with household pet exposure; apparent responsiveness of some RA cases to tetracycline therapy; the granulomatous and angioproliferative nature of Bartonella lesions; the insidiousness and high seroprevalence of this infection in the community; and even reported Bartonella infection mimicking juvenile RA. In a small group of patients with chronic arthritides, we found no direct evidence of humoral antibodies to, nor of persistent infection with, Bartonella henselae in synovial fluid. While larger and more invasive studies are likely to provide more confident exclusions of this hypothesis, this suggests that persistent Bartonella infection is unlikely to play a major role in RA.
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Affiliation(s)
- B Dillon
- University of Sydney, Westmead Hospital, Australia
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Hecht FM, Grant RM, Petropoulos CJ, Dillon B, Chesney MA, Tian H, Hellmann NS, Bandrapalli NI, Digilio L, Branson B, Kahn JO. Sexual transmission of an HIV-1 variant resistant to multiple reverse-transcriptase and protease inhibitors. N Engl J Med 1998; 339:307-11. [PMID: 9682043 DOI: 10.1056/nejm199807303390504] [Citation(s) in RCA: 347] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- F M Hecht
- AIDS Program, San Francisco General Hospital and University of California, 94110, USA
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Abstract
Food producers and consumers must continue to take precautions against foodborne diseases, and early diagnosis and appropriate treatment of these illnesses are essential. Food products and water can become contaminated with microorganisms and toxins that make people ill, and the very young, the elderly, and immunocompromised individuals are especially susceptible. Education of healthcare providers, food handlers, and the public is critical in reducing the incidence and spread of foodborne illness. Changes in eating habits and lifestyle and increased availability of both domestic and imported foods have made food hazards a more complex public health issue. Although most foodborne illnesses can be avoided by safe food handling procedures (see box on page 134), risk reduction is very important at every step from source to table. A concerted effort is needed to ensure continuing safety of the food supply in the United States while also assuring access to a wide variety of healthful foods. Time will tell whether consumers will accept irradiation of meats. If accepted, irradiation could rank in importance with pasteurization of milk and chlorination of water as a public health measure.
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Affiliation(s)
- R A Shewmake
- Department of Family Medicine, University of South Dakota School of Medicine, Sioux Falls 57105-1570, USA.
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Abstract
Rapid, on-site HIV testing with same-day results may improve services and increase the number of clients who learn their serostatus in developing countries. To validate test performance under field conditions and assess the change in the proportion of clients who learn their serostatus, we conducted a field trial using the Capillus HIV-1/HIV-2 assay (Cambridge Diagnostics) at the AIDS Information Centre counselling and testing sites in Uganda. Compared to the standard 2-EIA testing algorithm, the sensitivity of Capillus was 99.6% (95% CI; 98.5%, 99.9%), the specificity was 98.8% (95% CI; 98.1%, 99.3%), the positive predictive value was 96.5% (95% CI; 94.5%, 97.8%), and the negative predictive value was 99.9% (95% CI; 99.5%, 100%). It took less than 5 min to perform a single test, and results were returned to clients in less than an hour, during which time clients were counselled. This resulted in a 27% increase in the proportion of clients who learned their serostatus and received counselling. We conclude that simple, rapid HIV tests can be performed accurately on-site within the time frame of a clinic visit, increasing the number of clients who learn their serostatus and receive post-test counselling.
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Affiliation(s)
- W J Kassler
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA
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Yan W, Shen F, Dillon B, Ratnam M. The hydrophobic domains in the carboxyl-terminal signal for GPI modification and in the amino-terminal leader peptide have similar structural requirements. J Mol Biol 1998; 275:25-33. [PMID: 9451436 DOI: 10.1006/jmbi.1997.1447] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Proteins having a glycosyl-phosphatidylinositol (GPI) membrane anchor are synthesized with a carboxyl-terminal signal that is cleaved in the endoplasmic reticulum prior to GPI modification. The signal is characterized by a moderately hydrophobic domain downstream from the cleavage/modification site. The essential features of this domain were characterized using a truncated version of folate receptor (FR) type beta (FR-beta delta 5) in which its five carboxyl-terminal amino acid residues were deleted without affecting the efficiency of GPI modification. The amino acids at various positions in the hydrophobic domain were systematically altered and the extent of GPI modification of the recombinant proteins was determined by measuring [3H]folic acid binding at the cell surface, by Western blot analysis and from the sensitivity of the proteins to phosphatidylinositol-specific phospholipase C (PI-PLC). The results indicate that a threshold level of hydrophobicity exists at a single position below which the efficiency of GPI modification decreases with increasing hydrophilicity. Further, the hydrophobic domain is characterized by a hydrophobicity profile and not merely a minimum overall hydrophobicity. Thus, a leucine-rich core hydrophobic segment of six to eight amino acid residues is more sensitive to relatively small hydrophilic substitutions compared to its flanking regions and such mutations could be compensated by a hydrophobic substitution elsewhere within this core segment. Such a hydrophobicity profile is characteristic of the amino-terminal leader peptide. When the entire hydrophobic domain of the leader peptide of FR-beta (12 amino acid residues) was substituted with the hydrophobic domain of the GPI signal (13 amino acids), it was possible to obtain expression of FR-beta on the cell surface. In this construct, point mutations in the core hydrophobic segment and in the flanking regions within the substituting peptide produced a similar pattern of effects on the cell surface receptor expression compared to the corresponding mutations in the GPI signal of FR-beta. The results suggest that common principles may govern interactions of the hydrophobic domains of the GPI signal and the leader peptide with the endoplasmic reticulum.
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Affiliation(s)
- W Yan
- Department of Biochemistry and Molecular Biology, Medical College of Ohio, Toledo 43699-0008, USA
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Raucher B, Marchione S, McKinley F, Crimmins D, Dillon B, Martin S, Killip T. Tuberculosis (TB) control at a New York City tertiary care medical center. Am J Infect Control 1993. [DOI: 10.1016/0196-6553(93)90360-g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nine S, Bayes K, Christian S, Dillon B. Organizing quality assurance in a maternal-child health division. J Obstet Gynecol Neonatal Nurs 1992; 21:28-32. [PMID: 1564585 DOI: 10.1111/j.1552-6909.1992.tb01718.x] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The 10-step monitoring and evaluation process is described and applied to a maternal-child health division of a 300-bed tertiary care hospital. Examples of specific important aspects of care and indicators are given. The organized plan developed for this division is examined using the Joint Commission on Accreditation of Healthcare Organization's guidelines.
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Affiliation(s)
- S Nine
- Cabell Huntington Hospital, WV 25701
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Crimmins D, Raucher B, Marchione S, McKinley F, Dillon B. Dilemmas in the diagnosis of clostridium difficile at a tertiary care medical center. Am J Infect Control 1991. [DOI: 10.1016/0196-6553(91)90073-l] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Raucher B, McKinley FW, Crimmins D, Dillon B, Marchione S. JCAHO inspections for tertiary care facilities. Infect Control Hosp Epidemiol 1990; 11:226. [PMID: 2351806 DOI: 10.1086/646157] [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: 12/31/2022]
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Abstract
Using the technique of in vitro receptor autoradiography to slide-mounted tissue sections, we studied the suitability of [3H]-YM-09151-2 as a ligand for labeling D-2 receptors in adult F344 rat brains. Specific [3H]-YM-09151-2 binding accounted for 70-80% of the total bound ligand and reached equilibrium after a 60-90 minute incubation. Scatchard analysis revealed a Kd of 626 pM. The apparent Bmax was 23.2 fmol/tissue section. Autoradiographs demonstrated high grain densities in the striatum and olfactory tubercle. Diffuse specific binding was also observed in the cortex.
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Affiliation(s)
- A S Unis
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle 98195
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Affiliation(s)
- T E Keane
- Department of Surgery, General Hospital, Portlaoise, Ireland
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Moorehead RJ, Donaldson J, McKelvey STD, Drumm J, Harding LK, Clarke EA, Alexander-Williams J, Donovan IA, Lorigan G, Butler F, Broe PJ, O’Hara MJ, McCormick PA, Molloy A, McGrath D, O’Donoghue DP, Farrell T, O’Donoghue D, Daly L, Masterson JB, Breen EG, Coughlan J, Connolly CE, Stevens FM, McCarthy CF, Tobin MV, Fiskan RA, Dissory RT, Gilmore IT, McCormick D, Cullen A, McCormick PA, Towers RP, Keane RM, Coleman JE, Clery AP, Keane T, Dillon B, Afdhal NH, McCormick CJ, Stevens FM, Connolly CE, McCarthy CF, Hitchcock H, Waldron DJ, Fitzgerald RJ, Quigley EMM, Hall L, Turnberg LA, Brennan FN, Buchanan KD, Afdhal NH, Duffy MJ, Thornton A, O’Sullivan F, O’Donoghue DP, Mullen P, O’Connor B, Lombard M, Coakley JB, Crowe J, Lennon JR, Keeling P, Hennessy TPJ, Gleeson D, Quereshi Y, Murphy GM, Dowling RH, O’Connor HJ, Dixon MF, Wyatt JI, Axon ATR, Gillen P, Keeling P, Byrne PJ, West AB, Hennessy TPJ, Walsh TN, O’Higgins N, Quigley EMM, Turnberg LA, O’Hara MJ, McCormick PA, McGowan K, Miller JC, Masterson J, O’Donoghue DP, Courtney MG, McPartlin JM, Scott JM, Weir DG, Wilson BG, Howe JP, Parks TG, McCormick PA, Ramsay N, Afdhal N, Tubridy P, Shattock AG, Hillery I, O’Donoghue DP, Collins JSA, Knill-Jones RP, Crean GP, Love AHG, Quigley EMM, Hole DJ, Gillis CR, Watkinson G, Moore H, Moylan HE, Fottrell PF, Stevens FM, Brady HR, Godson C, Ryan MP, Bourke S, FitzGerald MX, McCormick PA, O’Farrelly C, Graeme-Cook F, Finch A, Feighery C, Weir DG, O’Donoghue DP, FitzGerald MX, Maxwell WJ, Walsh JP, Hogan FP, Kennedy NP, Keeling PWN, Sheil O, Barniville H, Fitzgerald O. Irish Society of Gastroenterology Proceedings of the Summer Meeting of the Irish Society of Gastroenterology, held in Universitly College, Cork on Friday 6th and Saturday 7th June, 1986. Ir J Med Sci 1987. [DOI: 10.1007/bf02953236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
We have reviewed our experience with reconstruction of eyebrow alopecia secondary to thermal injury in the pediatric patient. Reconstruction was performed with free composite strip grafts or vascularized island pedicle flaps. The complication rates for eyebrows reconstructed with vascularized island pedicles with respect to loss of a significant portion of the flaps (30.8 percent) and malalignment of the grafts (23.1 percent) were significantly greater (p less than 0.001) than the significant tissue loss (10.6 percent) or graft malalignment (7.9 percent) observed for free composite grafts. Hair density was more predictably restored with the free composite graft technique (p = 0.0004). The patients reconstructed with composite grafts had 89.4 percent acceptable results in contrast to 38.5 percent acceptable results obtained with the island pedicle technique. Based on these findings, we reserve the use of the vascularized island pedicle technique for male patients with unilateral alopecia and heavy hair density in the remaining eyebrow and in cases where free composite grafts have failed. The remaining patients are initially treated with free composite grafts with acceptable results in the overwhelming majority of cases.
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Abstract
This study evaluated the effect of 5 days of starvation followed by 5 days of refeeding on immunoreactive plasma and serum fibronectin and associated opsonic activity as studied by peritoneal macrophage monolayer bioassay in 12 healthy women volunteers. The temporal alteration of fibronectin was compared with the serum albumin, total iron-binding capacity, and retinol-binding protein levels. Fibronectin concentration and opsonic activity were also determined in two cachectic patients who were 61 and 78% of their ideal body weight. Prior to starvation, plasma fibronectin was 292 +/- 20 micrograms/ml and serum fibronectin was 182 +/- 16 in all subjects. After 5 days of starvation, immunoreactive fibronectin decreased (p less than 0.05) by 20-25%. This decrease was not great enough to impair opsonic activity as tested by the in vitro macrophage assay. Starvation caused no decrease in serum albumin or total iron-binding capacity, although retinol-binding protein decreased by 35%. During refeeding, subjects were randomized to a diet with (n = 6) and without (n = 6) carbohydrate. After 5 days of refeeding, fibronectin levels were normalized on the carbohydrate-containing diet, but were still low (82% of normal) on the carbohydrate-free diet. Retinol-binding protein did not fully normalize after 5 days of refeeding. In the two cachectic patients, fibronectin levels prior to total parenteral nutrition were 25 and 75% of normal. Thus, starvation can lower fibronectin levels and this protein is rapidly restored with adequate nutrition.
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Dillon B. Who do we fight? Australas Nurses J 1975; 4:5. [PMID: 1043746] [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: 12/25/2022]
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