MAR4 Streptomyces: A Unique Resource for Natural Product Discovery

Marine-derived Streptomyces have long been recognized as a source of novel, pharmaceutically relevant natural products. Among these bacteria, the MAR4 clade within the genus Streptomyces has been identified as metabolically rich, yielding over 93 different compounds to date. MAR4 strains are particularly noteworthy for the production of halogenated hybrid isoprenoid natural products, a relatively rare class of bacterial metabolites that possess a wide range of biological activities. MAR4 genomes are enriched in vanadium haloperoxidase and prenyltransferase genes, thus accounting for the production of these compounds. Functional characterization of the enzymes encoded in MAR4 genomes has advanced our understanding of halogenated, hybrid isoprenoid biosynthesis. Despite the exceptional biosynthetic capabilities of MAR4 bacteria, the large body of research they have stimulated has yet to be compiled. Here we review 35 years of natural product research on MAR4 strains and update the molecular diversity of this unique group of bacteria.

Structure and Candidate Biosynthetic Gene Cluster of a Manumycin-Type Metabolite from Salinispora pacifica

A new manumycin-type natural product named pacificamide (1) and its candidate biosynthetic gene cluster (pac) were discovered from the marine actinobacterium Salinispora pacifica CNT-855. The structure of the compound was determined using NMR, electronic circular dichroism, and bioinformatic predictions. The pac gene cluster is unique to S. pacifica and found in only two of the 119 Salinispora genomes analyzed across nine species. Comparative analyses of biosynthetic gene clusters encoding the production of related manumycin-type compounds revealed genetic differences in accordance with the unique pacificamide structure. Further queries of manumycin-type gene clusters from public databases revealed their limited distribution across the phylum Actinobacteria and orphan diversity that suggests additional products remain to be discovered in this compound class. Production of the known metabolite triacsin D is also reported for the first time from the genus Salinispora. This study adds two classes of compounds to the natural product collective isolated from the genus Salinispora, which has proven to be a useful model for natural product research.

Gut dysbiosis in cutaneous T-cell lymphoma is characterized by shifts in relative abundances of specific bacterial taxa and decreased diversity in more advanced disease

BACKGROUND

Cutaneous T-cell lymphoma (CTCL) patients often suffer from recurrent skin infections and profound immune dysregulation in advanced disease. The gut microbiome has been recognized to influence cancers and cutaneous conditions; however, it has not yet been studied in CTCL.

OBJECTIVES

To investigate the gut microbiome in patients with CTCL and in healthy controls.

METHODS

Case-control study conducted between January 2019 and November 2020 at Northwestern's busy multidisciplinary CTCL clinic (Chicago, Illinois, USA) utilizing 16S ribosomal RNA gene amplicon sequencing and bioinformatics analyses to characterize the microbiota present in fecal samples of CTCL patients (n=38) and age-matched healthy controls (n=13) from the same geographical region.

RESULTS

Gut microbial α-diversity trended lower in patients with CTCL and was significantly lower in patients with advanced CTCL relative to controls (p=0.015). No differences in β-diversity were identified. Specific taxa were significantly reduced in patient samples; significance was determined using adjusted p-values (q-values) that accounted for a false discovery rate threshold of 0.05. Significantly reduced taxa in patient samples included the phylum Actinobacteria (q=0.0002), classes Coriobacteriia (q=0.002) and Actinobacteria (q=0.03), order Coriobacteriales (q=0.003), and genus Anaerotruncus (q=0.01). The families of Eggerthellaceae (q=0.0007) and Lactobacillaceae (q=0.02) were significantly reduced in patients with high skin disease burden.

CONCLUSIONS

Gut dysbiosis can be seen in patients with CTCL compared to healthy controls and is pronounced in more advanced CTCL. The taxonomic shifts associated with CTCL are similar to those previously reported in atopic dermatitis and opposite those of psoriasis, suggesting microbial parallels to the immune profile and skin barrier differences between these conditions. These findings may suggest new microbial disease biomarkers and reveal a new angle for intervention.

Grincamycins P-T: Rearranged Angucyclines from the Marine Sediment-Derived Streptomyces sp. CNZ-748 Inhibit Cell Lines of the Rare Cancer Pseudomyxoma Peritonei

While marine natural products have been investigated for anticancer drug discovery, they are barely screened against rare cancers. Thus, in our effort to discover potential drug leads against the rare cancer pseudomyxoma peritonei (PMP), which currently lacks effective drug treatments, we screened extracts of marine actinomycete bacteria against the PMP cell line ABX023-1. This effort led to the isolation of nine rearranged angucyclines from Streptomyces sp. CNZ-748, including five new analogues, namely, grincamycins P-T (1-5). The chemical structures of these compounds were unambiguously established based on spectroscopic and chemical analyses. Particularly, grincamycin R (3) possesses an S-containing α-l-methylthio-aculose residue, which was discovered in nature for the first time. All of the isolated compounds were evaluated against four PMP cell lines and some exhibited low micromolar inhibitory activities. To identify a candidate biosynthetic gene cluster (BGC) encoding the grincamycins, we sequenced the genome of the producing strain, Streptomyces sp. CNZ-748, and compared the BGCs detected with those linked to the production of angucyclines with different aglycon structures.

A community resource for paired genomic and metabolomic data mining

Genomics and metabolomics are widely used to explore specialized metabolite diversity. The Paired Omics Data Platform is a community initiative to systematically document links between metabolome and (meta)genome data, aiding identification of natural product biosynthetic origins and metabolite structures.

Continuing Medical Education: A Needs Analysis of Anaesthetists

The continuing medical education (CME) needs of anaesthetists within Australia, New Zealand, Hong Kong, Malaysia and Singapore have been largely unknown. The aim of this study was to undertake a comprehensive survey of the attitude to CME, learning preferences, attitudes and abilities relating to self-paced material, literature and information searching, preferred content and preferred approach to CME of anaesthetists within these countries. A survey tool was developed and refined for ease of use by pilot-testing. The survey was mailed to 3,156 anaesthetists throughout Australia, New Zealand, Hong Kong, Malaysia and Singapore. Three options for data return were offered; postal reply, facsimile and a data entry web-page.

There were 1800 responses, which represented a response rate of 57%. The demographics of the respondents were similar to the overall demographics of Fellows of the Australian and New Zealand College of Anaesthetists. A large majority of respondents (92%) stated that their involvement in CME improved patient care. However, almost half the respondents reported that they have difficulty either in participating in current CME activities (31 %) or implementing new knowledge into their workplace (14%).

Anaesthetists within this region appear to be motivated by the need to make better decisions based on independent standards of practice. While Australia is a world leader in flexible education, it is still emerging as a discipline. Flexible education may be used to facilitate anaesthetists’ participation in CME activities and in implementation of new knowledge in their workplace.

National profile of foot orthotic provision in the United Kingdom, part 2: podiatrist, orthotist and physiotherapy practices

Background

A national survey recently provided the first description of foot orthotic provision in the United Kingdom. This article aims to profile and compare the foot orthoses practice of podiatrists, orthotists and physiotherapists within the current provision.

Method

Quantitative data were collected from podiatrists, orthotists and physiotherapists via an online questionnaire. The topics, questions and answers were developed through a series of pilot phases. The professions were targeted through electronic and printed materials advertising the survey. Data were captured over a 10 month period in 2016. Differences between professions were investigated using Chi squared and Fischer’s exact tests, and regression analysis was used to predict the likelihood of each aspect of practice in each of the three professions.

Results

Responses from 357 podiatrists, 93 orthotists and 49 physiotherapists were included in the analysis. The results reveal statistically significant differences in employment and clinical arrangements, the clinical populations treated, and the nature and volume of foot orthoses caseload.

Conclusion

Podiatrists, orthotists and physiotherapists provide foot orthoses to important clinical populations in both a prevention and treatment capacity. Their working context, scope of practice and mix of clinical caseload differs significantly, although there are areas of overlap. Addressing variations in practice could align this collective workforce to national allied health policy.

Electronic supplementary material

The online version of this article (10.1186/s13047-018-0250-9) contains supplementary material, which is available to authorized users.

A population-based study of visual impairment in the Lower Tugela health district in KZN, SA

A cross-sectional, population-based, epidemiological study of blindness and visual impairment was conducted to evaluate the prevalence of vision loss and various sight-threatening conditions in the Lower Tugela health district of the KwaZulu-Natal province, South Africa. This study was conducted on a randomly selected sample of 3444 individuals from the district. This number represented 84% of those who were visited and 80.1% of the total sample selected. The participants ranged in age from 5 to 93 years (mean of 29.2 years and a median of 20.0 years). The proportion of men to women differed between participants aged <30 years and those aged >30 years. In both age groups, women represented the majority of participants (66.5%), but the number of women to men in the older age group was approximately twice that found in the group aged less than 30 years. The difference in age between the men and women in the study was not statistically significant (p >0.5). The study revealed that 6.4% of the population studied were visually impaired. The distribution of uncorrected visual acuity was better for women than for men for both OD and OS (p = 0.000 for OD and OS). The main causes of visual impairment were refractive error (44.5%), cataract (31.2%), glaucoma (6.0%), hypertensive retinopathy (4.1%) and diabetic retinopathy (4.1%). Unilateral blindness (OD) was present in 0.78% (95% Confidence interval (CI): 0.42%-1.14%) of participants and unilateral blindness (OS) was present in 1.1% (95% CI: 0.70%-1.50%). Thirty-one participants (0.9%) were bilaterally blind with the main causes being cataracts (54.8%) and refractive error (12.9%). Glaucoma and hypertensive retinopathy were responsible for 6.4% of ..bilateral blindness. Diabetic retinopathy, other retinal conditions (coloboma) and corneal scarring were each responsible for 3.2% of bilateral blindness. Albinism, coloboma and age-related macular degeneration accounted for 9.7% of bilateral blindness. The data provides much needed information to support the planning of eye care programs in KwaZulu-Natal.  (S Afr Optom 2013 72(3) 110-118)

Multidose pharmacokinetics of orally administered florfenicol in the channel catfish (Ictalurus punctatus)

Plasma disposition of florfenicol in channel catfish was investigated after an oral multidose (10 mg/kg for 10 days) administration in freshwater at water temperatures ranging from 24.7 to 25.9 °C. Florfenicol concentrations in plasma were analyzed by means of liquid chromatography with MS/MS detection. After the administration of florfenicol, the mean terminal half-life (t(1/2)), maximum concentration at steady-state (Css (max)), time of Css (max) (T(max)), minimal concentration at steady-state (Css (min)), and Vc /F were 9.0 h, 9.72 μg/mL, 8 h, 2.53 μg/mL, and 0.653 L/kg, respectively. These results suggest that florfenicol administered orally at 10 mg/kg body weight for 10 days could be expected to control catfish bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of <2.5 μg/mL.

Identification of Porphyromonas levii isolated from clinical cases of bovine interdigital necrobacillosis by 16S rRNA sequencing

Laboratories use pigmentation, antibiotic susceptibility, and biochemical tests to identify anaerobic organisms that play a role in bovine interdigital necrobacillosis (bovine foot rot). In this study, 16S rRNA gene sequencing was used to identify strains to the species level that were originally classified as Prevotella or Porphyromonas spp by conventional phenotype assessment methods. Of 264 qualified strains from ceftiofur clinical trials, 241 isolates were definitively identified by 16S rRNA sequencing as Porphyromonas levii. Similarly, of 275 qualified strains from tulathromycin clinical trials, 156 isolates were definitively identified by 16S rRNA sequencing as P. levii. The predominance of P. levii in this study supports the role of this organism as an associative agent of bovine foot rot and may have implications for routine laboratory diagnosis.

5-Azacytidine-treated human mesenchymal stem/progenitor cells derived from umbilical cord, cord blood and bone marrow do not generate cardiomyocytes in vitro at high frequencies

BACKGROUND AND OBJECTIVES

Mesenchymal stem/progenitor cells (MSCs) are multipotent progenitors that differentiate into such lineages as bone, fat, cartilage and stromal cells that support haemopoiesis. Bone marrow MSCs can also contribute to cardiac repair, although the mechanism for this is unclear. Here, we examine the potential of MSCs from different sources to generate cardiomyocytes in vitro, as a means for predicting their therapeutic potential after myocardial infarction.

MATERIALS AND METHODS

Mesenchymal stem/progenitor cells were isolated from the perivascular tissue and Wharton's jelly of the umbilical cord and from cord blood. Their immunophenotype and differentiation potential to generate osteoblasts, chondrocytes, adipocytes and cardiomyoxcytes in vitro was compared with those of bone marrow MSCs.

RESULTS

Mesenchymal stem/progenitor cells isolated from umbilical cord and cord blood were phenotypically similar to bone marrow MSCs, the exception being in the expression of CD106, which was absent on umbilical cord MSCs, and CD146 that was highly expressed in cord blood MSCs. They have variable abilities to give rise to osteoblasts, chondrocytes and adipocytes, with bone marrow MSCs being the most robust. While a small proportion (approximately 0.07%) of bone marrow MSCs could generate cardiomyocyte-like cells in vitro, those from umbilical cord and cord blood did not express cardiac markers either spontaneously or after treatment with 5-azacytidine.

CONCLUSION

Although MSCs may be useful for such clinical applications as bone or cartilage repair, the results presented here indicate that such cells do not generate cardiomyocytes frequently enough for cardiac repair. Their efficacy in heart repair is likely to be due to paracrine mechanisms.

Use of autologous bone marrow cells following high-dose chemotherapy (HDCT) for patients (pts) with recurrent lymphoma in whom stem cell harvesting from the peripheral blood was inadequate

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Background: HDCT with autologous stem cell rescue (ASCR) is an established treatment for recurrent Hodgkin and non- Hodgkin lymphoma (HL, NHL) but some of these pts fail to mobilise adequate numbers of CD34+ cells from the peripheral blood (PB). Harvest of bone marrow (BM) stem cells and use of these alone or in combination with PB derived cells is an option but there are concerns about feasibility and outcome. Methods: 29 pts who had HDCT after failed PB stem cell harvest between July 1999 and December 2005 were studied in terms of CD34+ cell yield (PB and BM), transfusion dependence, engraftment and survival. Results: There were 17 males and 12 females (median age 49yrs, range 19–66) with recurrent HL (n=16) or NHL (n=13). All had received at least 2 lines of chemotherapy (10 pts =3) and 7 had received radiotherapy (5 mediastinal, one neck and one abdominal field). Mobilisation of CD34+ cells from PB was attempted using chemotherapy followed by filgrastim. 22 pts proceeded to leukapheresis on the basis of predictive CD34+ counts (median collects 2; range 0–4) with a median total collect of 0.98×106 CD34+cells/kg (range 0.03–1.84). Subsequently, all pts had a BM harvest producing a median collect of 1.63x106 CD34+cells/kg (range 0.45–4.75). 29 pts then received BEAM/CBV followed by re-infusion of PB+BM cells except in 7 pts where only BM cells were available. In 26/29 pts surviving to day 100; total CD34+ cells infused, 2.37×106/kg (range 1.73- 5.0), time to neutrophils >0.5×109/L, 12 days (range 9–23), platelet units transfused, 6 (range 0–24), red cells units transfused 6 (range 0–18) (all medians). 2 pts continued to have red cell transfusions beyond day 100. 3/29 pts died due to severe neutropenia/septicaemia at days 23–25 (treatment related mortality 10.3%); the CD34+ dose received by these pts was 1.97×106/kg in 2 and 1.84×106/kg in 1. Beyond day 100, 9 pts have died from HL/NHL and 2 are lost to follow-up. Conclusions: In patients with HL/NHL who fail to mobilise adequate numbers of CD34+ cells from PB, a BM harvest can produce a combined BM/PB collect capable of producing haemopoeitic reconstitution following HDCT without excessive toxicity.

No significant financial relationships to disclose.

Behaviour and emotional problems in toddlers with pervasive developmental disorders and developmental delay: associations with parental mental health and family functioning

BACKGROUND

Behavioural and emotional problems occur at a high rate in children and adolescents with intellectual disability, often from a young age. Some studies have indicated that children and adolescents with autism present with even higher rates. Less is known about the presentation, development and family impact of these difficulties in young children with autism. This study aimed to explore these issues in toddlers with pervasive developmental disorders (PDDs), those with delay without a PDD, and their families.

METHODS

Participants were 123 children aged 20-51 months, referred to a developmental assessment clinic. Parents completed a checklist on child behavioural and emotional problems, and individual questionnaires on family functioning, their own mental health, and stress in relation to parenting their child. The child's language and cognitive skills, adaptive functioning and behaviour were assessed by standardized measures. Measures were repeated 1 year postdiagnosis. Behavioural and emotional problems in young children with a PDD were compared with those in children with developmental delay without a PDD, and their impact on parental outcomes explored over time.

RESULTS

Initial and follow-up measures of child behaviour and emotional problems, parent mental health problems, parent stress and family functioning were significantly correlated, providing some evidence of stability over time. Child emotional and behavioural problems contributed significantly more to mother stress, parent mental health problems, and perceived family dysfunction than child diagnosis (PDD/non-PDD), delay or gender. Compared with mothers, all fathers reported significantly less stress in relation to parenting their child.

CONCLUSION

Results highlighted the importance of addressing emotional and behavioural problems in very young children with autism and/or developmental delay. The need for early support and intervention for mothers, fathers and families in this context was also evidenced. As research has shown that behavioural and emotional problems persist into adolescence and young adulthood, understanding of these issues in very young children and their parents has important implications for intervention and long-term outcomes.

The identification of three novel MICA alleles by sequence-based typing

During a study of MICA frequency in a healthy population and a cohort of patients suffering with inflammatory bowel disease, three DNA samples produced unusual reactivity patterns using polymerase chain reaction sequence-specific primers (PCR-SSP). These samples were subsequently characterized by sequence-based typing (SBT). Here, we report the sequence of these three novel MICA alleles.

Identification of a novel MICA allele: MICA*051

We have identified a novel MICA allele, MICA*051, detected by the polymerase chain reaction using sequence-specific primers and characterized by sequence-based typing. MICA*051 appears to be the result of a recombination between MICA*00801 and MICA*00701 at intron 2.

A novel major histocompatibility complex class I-related chain allele

We report the identification of a novel major histocompatibility complex class I-related chain (MICB) allele, provisionally designated as MICB-0114 pending the WHO Nomenclature Classification for the MICB locus. This new allele is identical to MICB-0103101v except for a single mutation of G to A in exon 4 that translates into an amino acid substitution from glutamic acid to lysine.

A Thermal Analogy for Modelling Drug Elution from Cardiovascular Stents

Restriction of blood flow by the narrowing or occlusion of arteries is one of the most common presentations of cardiovascular disease. One treatment involves the introduction of a metal scaffold, or stent, designed to prevent recoil and to provide structural stability to the vessel. On the occasions that this treatment is ineffective, failure is usually associated with re-invasion of tissue. This can be prevented by local delivery of drugs which inhibit tissue growth. The drug might be delivered locally in a polymer coating on the stent. This paper develops and explores the use of a thermal analogue of the drug delivery process and the associated three-dimensional convection-diffusion equation to model the spatial and temporal distribution of drug concentration within the vessel wall. This allows the routine use of commercial finite element analysis software to investigate the dynamics of drug distribution, assist in the understanding of the treatment process and develop improved delivery systems. Two applications illustrate how the model might be used to investigate the effects of controllable or measurable parameters on the progression of the process. It is demonstrated that the geometric characteristics of the stent can have significant impact on the homogeneity of the dosing in the vessel wall.

Haematological profiles in pure bred cattle naturally infected with Theileria annulata in Saudi Arabia

The Abbott Cell Dyn 3500 haematology analyzer was employed to study haematological parameters in 41 adult and young Friesian cattle naturally infected with Theileria annulata in the Qassim region of Saudi Arabia. Comparison was made with clinically healthy adult and young Friesian cattle. Changes in blood parameters in T. annulata-infected cattle indicated severe macrocytic hypochromic anaemia, panleukopenia, lymphocytopenia, eosinopenia, neutropenia and thrombocytopenia but no reticulocytosis.

Intracellular localization of phospholipase D1 in mammalian cells

Phospholipase D (PLD) hydrolyzes phosphatidylcholine to generate phosphatidic acid. In mammalian cells this reaction has been implicated in the recruitment of coatomer to Golgi membranes and release of nascent secretory vesicles from the trans-Golgi network. These observations suggest that PLD is associated with the Golgi complex; however, to date, because of its low abundance, the intracellular localization of PLD has been characterized only indirectly through overexpression of chimeric proteins. We have used highly sensitive antibodies to PLD1 together with immunofluorescence and immunogold electron microscopy as well as cell fractionation to identify the intracellular localization of endogenous PLD1 in several cell types. Although PLD1 had a diffuse staining pattern, it was enriched significantly in the Golgi apparatus and was also present in cell nuclei. On fragmentation of the Golgi apparatus by treatment with nocodazole, PLD1 closely associated with membrane fragments, whereas after inhibition of PA synthesis, PLD1 dissociated from the membranes. Overexpression of an hemagglutinin-tagged form of PLD1 resulted in displacement of the endogenous enzyme from its perinuclear localization to large vesicular structures. Surprisingly, when the Golgi apparatus collapsed in response to brefeldin A, the nuclear localization of PLD1 was enhanced significantly. Our data show that the intracellular localization of PLD1 is consistent with a role in vesicle trafficking from the Golgi apparatus and suggest that it also functions in the cell nucleus.

Infiltrative keratitis associated with extended wear of hydrogel lenses and Abiotrophia defectiva

PURPOSE

Infiltrative keratitis is a common complication associated with extended wear of hydrogel lenses. Causative bacteria are often isolated from the lens at the time of an event. We report a case where three repeated occurrences of infiltrative keratitis were associated with contamination of the contact lenses by Abiotrophia defectiva.

METHODS

A 34-year-old man participating in a clinical trial of extended wear hydrogel contact lenses experienced three episodes of infiltrative keratitis. The clinical presentation was observed using a biomicroscope. At the time of each event, the contact lenses were removed aseptically and ocular swabs were taken for bacterial identification and enumeration. The condition was monitored until full resolution.

RESULTS

The condition was characterized by irritation, marked bulbar and limbal injection, and multiple focal subepithelial infiltrates. Many of the infiltrates also showed overlying staining with fluorescein. In each of the three events of infiltrative keratitis, A. defectiva was cultured from the contact lens and ocular swabs.

CONCLUSION

This is the first reported occurrence of infiltrative keratitis associated with A. defectiva contamination of contact lenses.

Trichomonad invasion of the mucous layer requires adhesins, mucinases, and motility

BACKGROUND/OBJECTIVE

Trichomonas vaginalis, the causal agent of trichomonosis, is a flagellated parasitic protozoan that colonises the epithelial cells of the human urogenital tract. The ability of T vaginalis to colonise this site is in part a function of its ability to circumvent a series of non-specific host defences including the mucous layer covering epithelial cells at the site of infection. Mucin, the framework molecule of mucus, forms a lattice structure that serves as a formidable physical barrier to microbial invasion. The mechanism by which trichomonads traverse the mucous covering is unknown. Proteolytic degradation of mucin, however, may provide for a mechanism to penetrate this layer. The goal, therefore, was to determine how trichomonads cross through a mucous layer.

METHODS

Secreted trichomonad proteinases were analysed for mucinase activity by mucin substrate-sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The importance of trichomonad mucinases for traversing the mucous layer was examined on an artificial mucin layer in invasion chambers. Adherence to mucin and tissue culture cells was measured using a microtitre plate assay.

RESULTS

Trichomonad isolate 24402 secreted five proteinases when incubated in PBS. All five proteinases were shown to possess mucinase activity. These mucinases were able to degrade bovine submaxillary mucin and to a lesser extent porcine stomach mucin. These enzymes were active over a pH range of 4.5-7.0 and were inhibited with cysteine proteinase inhibitors. Furthermore, T vaginalis was shown to bind to mucin possibly via a lectin-like adhesin. Adherence to mucin was increased threefold when parasites were grown in iron deficient medium. Adherence to soluble mucin prevented attachment to HeLa cells. Proteinase activity, adherence, and motility were required for trichomonads to traverse a mucin layer in vitro.

CONCLUSIONS

These results show that trichomonads can traverse the mucous barrier first by binding mucin followed by its proteolytic degradation. The data further underscore the importance of trichomonad proteinases in the pathogenesis of trichomonosis. Finally, this study suggests that interference with trichomonad mucin receptors and proteinases may be a strategy to prevent colonisation by this parasite.

2-Substituted-4-methoxybenzimidazole-based PDE4 inhibitors

A new family of PDE4 inhibitors based on a benzimidazole framework is described. Several of these compounds are orally bioavailable and show efficacy in in vivo models of inflammatory disease.

Human factors in technology replacement: a case study in interface design for a public transport monitoring system

This paper describes ergonomic issues raised during a project to provide a replacement real-time bus route control system to a large public transport company. Task and system analyses highlighted several deficiencies in the original system architecture, the human-machine interfaces and the general approach to system management. The eventual live prototype replaced the existing original system for a trial evaluation period of several weeks. During this period a number of studies was conducted with the system users in order to measure any improvements the new system, with its ergonomic features, produced over the old. Importantly, the results confirmed that (a) general responsiveness and service quality were improved, and (b) users were more comfortable with the new design. We conclude with a number of caveats which we believe will be useful to any group addressing technology impact in a large organisation.

Generation of Alzheimer beta-amyloid protein in the trans-Golgi network in the apparent absence of vesicle formation

beta-amyloid protein (A beta) formation was reconstituted in permeabilized neuroblastoma cells expressing human Alzheimer beta-amyloid precursor protein (beta APP) harboring the Swedish double mutation associated with familial early-onset Alzheimer disease. Permeabilized cells were prepared following metabolic labeling and incubation at 20 degrees C, a temperature that allows beta APP to accumulate in the trans-Golgi network (TGN) without concomitant A beta formation. Subsequent incubation at 37 degrees C led to the generation of A beta. A beta production in the TGN persisted even under conditions in which formation of nascent post-TGN vesicles was inhibited by addition of guanosine 5'-O-(3-thiotriphosphate), a nonhydrolyzable GTP analogue, or by omission of cytosol. These and other results indicate that vesicle budding and trafficking may not be required for proteolytic metabolism of beta APP to A beta, a process that includes "gamma-secretase" cleavage within the beta APP transmembrane domain.

Increased apolipoprotein E epsilon 4 in epilepsy with senile plaques

Inheritance of the apolipoprotein E (ApoE) epsilon 4 allele is a risk factor for Alzheimer's disease (AD) and is associated with increased deposition of beta-amyloid (A beta) in AD, Down's syndrome, and normal aging. A beta deposition in the form of senile plaques (SPs) has recently been described in patients with temporal lobe epilepsy (TLE). We studied the relationship between ApoE epsilon 4 genotype and the deposition of A beta in temporal lobe tissue from patients who underwent temporal lobectomy for intractable epilepsy. TLE patients with SPs had a 70% ApoE epsilon 4 carrier frequency compared with a 27% carrier frequency among age-matched TLE controls without SPs. Our data suggest that the association between ApoE epsilon 4 and intracerebral A beta accumulation is not unique to the elderly or to those with dementia, and may be a feature of conditions in which there is both an ApoE epsilon 4 allele and over-production of A beta precursor protein, and, presumably, A beta.

The profile of soluble amyloid beta protein in cultured cell media. Detection and quantification of amyloid beta protein and variants by immunoprecipitation-mass spectrometry

To study the metabolism of amyloid beta protein (Abeta) in Alzheimer's disease, we have developed a new approach for analyzing the profile of soluble Abeta and its variants. In the present method, Abeta and its variants are immuno-isolated with Abeta-specific monoclonal antibodies. The identities of the Abeta variants are determined by measuring their molecular masses using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The levels of Abeta variants are determined by their relative peak intensities in mass spectrometric measurements by comparison with internal standards of known identities and concentrations. We used this method to examine the Abeta species in conditioned media of mouse neuroblastoma cells transfected with cDNAs encoding wild type or mutant human amyloid precursor protein. In addition to human Abeta-(1-40) and Abeta-(1-42), more than 40 different human Abeta variants were identified. Endogenous murine Abeta and its variants were also identified by this approach. The present approach is a new and sensitive method to characterize the profile of soluble Abeta in conditioned media and biological fluids. Furthermore, it allows direct measurement of each individual peptide in a peptide mixture and provides comprehensive information on the identity and concentration of Abeta and Abeta variants.

The Big-Five factor structure as an integrative framework: an analysis of Clarke's AVA model

Using a large (N = 3,629) sample of participants selected to be representative of U.S. working adults in the year 2,000, we provide links between the constructs in 2 personality models that have been derived from quite different rationales. We demonstrate the use of a novel procedure for providing orthogonal Big-Five factor scores and use those scores to analyze the scales of the Activity Vector Analysis (AVA). We discuss the implications of our many findings both for the science of personality assessment and for future research using the AVA model.

Metabolism of Alzheimer beta-amyloid precursor protein: regulation by protein kinase A in intact cells and in a cell-free system

Various compounds that affect signal transduction regulate the relative utilization of alternative processing pathways for the beta-amyloid precursor protein (beta APP) in intact cells, increasing the production of nonamyloidogenic soluble beta APP (s beta APP) and decreasing that of amyloidogenic beta-amyloid peptide. In a recent study directed toward elucidating the mechanisms underlying phorbol ester-stimulated s beta APP secretion from cells, it was demonstrated that protein kinase C increases the formation from the trans-Golgi network (TGN) of beta APP-containing secretory vesicles. Here we present evidence that forskolin increases s beta APP production from intact PC12 cells, and protein kinase A stimulates formation from the TGN of beta APP-containing vesicles. Although protein kinase A and protein kinase C converge at the level of formation from the TGN of beta APP-containing vesicles, additional evidence indicates that the regulatory mechanisms involved are distinct.

Case report: severe hyperkalemia in a geriatric patient receiving standard doses of trimethoprim-sulfamethoxazole

A case is reported of a 96-year-old woman with congestive heart failure, hypertension, and chronic obstructive pulmonary disease who presented with altered mental status and severe hyperkalemia, a serum potassium 9.3 meq/L, and electrocardiograph changes. The patient was discharged 1 week prior, with a normal serum potassium, receiving trimethoprim-sulfamethoxazole for urinary tract infection and pneumonia. Serum potassium measurements returned to normal after discontinuation of the drug. Other causes of hyperkalemia were ruled out. Mild hyperkalemia due to trimethoprim-sulfamethoxazole was first reported in 1983 in a 69-year-old woman in whom leukemia with leukopenia developed. In literature to date, mild hyperkalemia in younger geriatric patients has been described. Trimethoprim is thought to act by inhibiting amiloride sensitive sodium channels in the distal nephron and impairing renal potassium secretion in a dose dependent manner. The authors report the case, review the literature, and discuss age-related reduction in renal function as a possible etiology.

Fibronectin in the tear film

PURPOSE

Fibronectin plays an important role in corneal healing and has been detected previously in the tear film. To investigate the levels of fibronectin in normal human tears, the authors measured and compared fibronectin concentration in open-eye, closed-eye, and reflex tear fluid. The origin of fibronectin in the tear film was investigated by comparing fibronectin concentration in sequentially collected reflex tear samples with the concentrations of total protein and albumin in the same samples.

METHODS

Open-eye and closed-eye tears were collected from 11 noncontact lens wearers. From 7 subjects, 20 uninterrupted reflex tear samples (10 microliters each) subsequently were collected, using the sneeze reflex method of stimulation, followed by an additional 10 nonstimulated tear samples (3 microliters each) immediately after cessation of stimulus. Enzyme-linked immunosorbent assays were used to determine fibronectin and albumin concentrations, and bicinchoninic acid protein assays were used to determine total protein concentration in each sample.

RESULTS

Fibronectin concentration in open-eye tears (19 +/- 24 eta g/ml, range 3 to 78 eta g/ml) was significantly different (P = 0.004) from that in closed-eyes tears (4127 +/- 3222 eta g/ml, range 1177 to 11384 eta g/ml). In the first 50 microliters of reflex tears, fibronectin concentrations were low (10 +/- 23 eta g/ml), but they increased significantly (P = 0.028) after 100 microliters of reflex tears had been collected (220 +/- 126 eta g/ml). There was a further marked transient increase (767 +/- 946 eta g/ml) after cessation of stimulus. Total protein concentration in the same samples decreased significantly during reflex tear collection compared to open-eye tears, and it increased gradually after cessation of stimulus. Albumin concentration in the same samples, analyzed for two subjects only, showed a pattern similar to that for fibronectin. Dilation of conjunctival blood vessels was noted in all subjects after reflex tear collection. Administration of a topical vasoconstrictor in two subjects eliminated the increase in fibronectin concentration during reflex tearing but did not affect total protein concentration. Under reducing conditions, the molecular mass of fibronectin in open-eye and reflex tears was 240 kDa, identical to commercially available purified plasma fibronectin, whereas fibronectin in closed-eye tears was degraded into small molecular mass fragments.

CONCLUSIONS

These findings suggest that fibronectin in tear fluid is derived from plasma and that the increase in concentration in closed-eye and reflex tear fluid is caused by leakage from dilated conjunctival blood vessels.

High levels of amyloid-beta protein from S182 (Glu246) familial Alzheimer's cells

Most early-onset familial Alzheimer disease is associated with missense mutations in S182, a membrane protein on chromosome 14. We investigated amyloid-beta protein (A beta) precursor (A beta PP) metabolism in skin fibroblasts from S182 (Glu246)-affected individuals and unaffected family members. Steady-state A beta PP levels were similar among all lines as was the degree of increase in soluble A beta PP released upon stimulation of cells with either phorbol ester or serum. Among all lines studied, A beta levels were consistently detectable only in the medium of a single line of S182 (Glu246) cells, consistent with the conclusion that some S182 mutant lines may accumulate A beta in their conditioned media. Studies of cells from additional individuals and under other conditions will be required to establish this association of elevated A beta levels with S182 mutations.

CCLRU standards for success of daily and extended wear contact lenses

Success in contact lens wear is often judged on the basis of patient "survival" rather than the achievement of satisfactory performance based on specific criteria. In 1971, Sarver and Harris defined a series of standards for successful polymethyl methacrylate (PMMA) lens wear which incorporated criteria for wearing time, comfort, vision, ocular tissue changes, and patient appearance. In this paper we propose a revision of these criteria based on current understanding of the ocular response to contact lens wear. These revised CCLRU (Cornea and Contact Lens Research Unit) standards for success are intended as realistic performance objectives, and can be applied in clinical trials to evaluate and compare the clinical performance of present and future rigid and soft contact lenses, worn for daily and extended wear.

Sodium dodecyl sulphate-polyacrylamide gel electrophoresis of human parotid salivary proteins

The proteins in human parotid saliva have been separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis into 20 or more well resolved species. The Coomassie Brilliant Blue (CBB) R-250 and silver staining procedures have been modified to overcome the problems encountered with staining of proline-rich proteins. By means of the CBB R-250 procedure which stains proline-rich proteins pink-violet, immunoblotting, concanavalin A binding, periodate-Schiff staining and zinc binding, all of the major proteins have been characterised. Substantial individual-to-individual differences were observed in the protein patterns formed. Comparison of parotid, submandibular, and whole saliva from a single individual indicated that fewer proline-rich proteins are expressed in submandibular saliva than in parotid, but whole saliva contains much lower levels than either duct secretion. The results will form a useful base for future research into the functions of salivary proteins.

Salivary secretion of albumin in type 1 (insulin-dependent) diabetes

The concentration of albumin in saliva is low in healthy humans. To determine whether alterations in capillary permeability in diabetes affects the salivary glands, the concentration of albumin in parotid saliva was measured in 26 Type 1 (insulin-dependent) diabetic patients, and compared to 32 non-diabetic control subjects. The diabetic patients were subdivided into 3 groups on the basis of the urinary excretion of albumin in timed overnight collections of urine: (1) normal albumin excretion (less than 30 micrograms/min) n = 13; (2) microalbuminuria (30-300 micrograms/min) n = 7, and (3) macroalbuminuria (greater than 300 micrograms/min) n = 6. Saliva was collected for one minute following stimulation with 1 ml 10% citric acid, and the concentration of albumin was measured by a sensitive ELISA method. No significant difference in salivary albumin concentration was found between the control group and any of the diabetic groups. Thus, although urinary albumin excretion was increased, suggesting altered capillary permeability, simultaneous leakage of albumin into saliva was not observed. Measurement of salivary albumin concentration does not, therefore, provide a marker of occult microvascular disease in diabetes.

An enzyme-linked immunoassay for human salivary albumin

An ELISA method has been developed for the determination of albumin in human parotid saliva. The range of sensitivity is 2-80 micrograms/l and it is suitable for use with volumes of 5 microliters or less of freshly collected parotid fluid, without prior sample preparation. Calibration data were fitted by microcomputer to an exponential function. The albumin concentration of parotid saliva was 1.9 +/- 1.53 mg/l, but levels fell on sample storage. Isoelectric focusing, followed by immunoblotting with antiserum to human serum albumin, showed identical double bands of pI 4.9-5.0 in albumin from both serum and saliva, thereby confirming that the antigens from the two sources are identical.

Microbial infection and the septic response in critical surgical illness. Sepsis, not infection, determines outcome

The differential roles of infection as a microbial phenomenon and sepsis as a host response were studied in 210 critically ill surgical patients. Infections occurred in 41.4% of all cases and in 82% of nonsurviving patients. Both infection and the expression of a septic response, measured as a sepsis score, were associated with significantly increased intensive care unit morbidity and mortality. Nonsurviving patients with infection had significantly higher sepsis scores than did survivors. Nonsurvivors with sepsis, on the other hand, did not differ from survivors with respect to any variable reflecting infection but did have higher mean sepsis scores. Maximum sepsis scores and sepsis scores on the day of death were similar in patients dying without infection and those dying with uncontrolled infection. The magnitude of the host septic response, independent of the presence, bacteriologic characteristics, or control of infection, is an important determinant of outcome in critical surgical illness.

Quantitative analysis of polyols in human plasma and cerebrospinal fluid

We used gas chromatography in conjunction with flame ionization detection to quantitate nine polyols and aldo and keto sugars (as silyl derivatives) in human plasma and cerebrospinal fluid (CSF). Rhamnose, not found in CSF or plasma, was used as an internal standard with a lower limit of quantitation of 0.4 mg/l. CSF polyol and sugar concentrations (mean +/- S.D.) in fourteen healthy subjects (age range 27.1-85.9 years) were: anhydroglucitol, 19.9 +/- 5.3 mg/l; arabitol, 4.8 +/- 0.9 mg/l; erythritol, 2.4 +/- 0.5 mg/l; myoinositol, 28.6 +/- 8.3 mg/l; ribitol, 1.6 +/- 0.1 mg/l; fructose, 25.5 +/- 11.1 mg/l; glucose, 587 +/- 70 mg/l; glucitol, 7.7 +/- 1.5 mg/l; and mannose, 10.6 +/- 2.4 mg/l. The respective plasma concentrations were 30.6 +/- 11.5, less than 0.4, 0.4 +/- 0.2, 6.3 +/- 2.6, less than 0.4, 23.4 +/- 21.4, 897 +/- 214, less than 0.4 and 13.7 +/- 6.3 mg/l. Polyol CSF-to-plasma concentration ratios greater than 2 were observed for myoinositol, erythritol, arabitol, glucitol and ribitol, indicative of active accumulation or synthesis of these polyols within the central nervous system.

Coping strategies and diastolic blood pressure

An organizational field study involving 95 civil service employees examined the ways these individuals coped with the stressful events of their daily living. Lazarus' cognitive-phenomenological analysis of psychological stress provided the theoretical framework. Subjects indicated on Lazarus' Ways of Coping Checklist those coping thoughts and actions used in the specific encounter described as stressful. As hypothesized, individuals experiencing higher diastolic blood pressure were more likely to cope using strategies characterized by wishful thinking, avoidance, and minimization of threat than were individuals exhibiting lower blood pressure. Implications from both an individual and organizational perspective are discussed.

The effect of RG 12525 on leukotriene D4-mediated pulmonary responses in guinea pigs

RG 12525 (5-(2-[4-quinolin-2-yl)methoxyl] phenoxymethyl)benzyl tetrazole) is under investigation as a specific inhibitor of leukotriene D4 (LTD4). The present studies examine the effect of orally administered RG 12525 on LTD4 mediated pulmonary responses in three separate guinea pig models. The compound inhibited antigen-induced mortality in the systemic anaphylaxis model with an ED50 (95% confidence interval) = 2.2 (0.8-6.4) mg/kg. In this model, the activity half-life of RG 12525 was shown to be 6.5 hours and the compound offered significant protection within 15 minutes of administration. RG 12525 also protected against LTD4-induced bronchoconstriction in a model measuring changes in pulmonary function with an ED50 = 0.6 (0.4-1.0) mg/kg. The same level of activity was observed in a similar model which monitored changes in pulmonary function in response to exogenous antigen in actively-sensitized guinea pigs. Together, these data indicate that RG 12525 is a potent, orally active LTD4 antagonist which possesses the requisite profile for potential clinical development.

Neuropsychiatric assessment of a spinal cord injury patient with sudden recovery

Reported here is the case of a 23-year-old man who, presenting as a spinal cord injury patient with paraplegic and bilateral sensory impairments in the legs, made a rather dramatic recovery after receiving a trivial jolt while moving about in his wheelchair. In addition to clinical findings, both hypnotic and somatosensory evoked potential test results were used to help determine whether there was or was not actual spinal cord injury and whether there was or was not a psychologic overlay involving either malingering or a conversion disorder. In this case, evidence pointed to malingering in the presence of a minor spinal cord injury documented by somatosensory evoked potential patterns.

Co-oxidation of arachidonic acid and methimazole by prostaglandin endoperoxide synthetase

The thiocarbamide methimazole stimulated O2 utilisation when added to reaction mixtures containing ram seminal vesicle microsomes (prostaglandin endoperoxide synthetase preparation) and arachidonic acid. This stimulation increased with increasing methimazole concentrations, as did the production of prostaglandin E. 2-[14C]Methimazole was co-oxidized to 1-methyl-2-[14C]imidazole.

The effect of halothane general anaesthesia on platelet function

Major craniofacial surgery has the potential for very large blood loss, frequently greater than one blood volume. In order that an assessment could be made of any deficiencies of platelet function or coagulation, tests were performed at intervals during the operation. None of the coagulation parameters showed variation below normal limits during the operation, but in vitro platelet aggregation showed significant decreases to several agonists.

Eating disorders and cocaine abuse: a survey of 259 cocaine abusers

A structured clinical interview designed to diagnose eating disorders was administered to 259 consecutive callers to the National Cocaine Hotline who met DSM-III criteria for cocaine abuse. Thirty-two percent of those surveyed met DSM-III criteria for either anorexia nervosa, bulimia, or both disorders. The prevalence rates for each of these disorders in this sample appeared elevated even when narrow diagnostic criteria were applied. The data suggest that drug abusers should be screened carefully for the presence of an eating disorder and that abnormalities of eating behaviors seen among these individuals should not be attributed simply to drug use.