Testing for HIV and sexually transmissible infections within a mainly online sample of gay men who engage in group sex

INTRODUCTION

Group sex among gay men has been associated with other HIV risk behaviours. Gay men who engage in group sex may be at increased risk of infection with HIV and other sexually transmitted infections (STI).

METHODS

The Three or More Study (TOMS) of group sex among gay men utilised an anonymous, self-completed survey about participants' most recent occasion of group sex with other men and in-depth interviews with a small number of these survey participants. The 436 men who reported having engaged in group sex within the previous month were included in these analyses.

RESULTS

Among 436 men who engaged in group sex within the previous month, 32.5% reported unprotected anal intercourse (UAI) with non-regular, mostly HIV non-seroconcordant partners at this recent group sex encounter (GSE) and the majority reported other sex practices that are risk factors for STI other than HIV. Over one-third reported having been tested for HIV or other STI since their last GSE; those who had engaged in UAI at the GSE were more likely to have been tested (p = 0.008). Men who had a doctor with whom they were able to discuss their group sex activities had received a broader range of STI tests (p = 0.003).

CONCLUSION

Sex practices that risk the transmission of STI were common within this high-risk sample, whereas awareness of risk and the need for testing was high but not universal. Frank discussion with doctors of patients' group sex behaviour also enhanced decisions about adequate testing. Gay men in group sex networks are an appropriate priority for sexual health screening.

A refined diagnostic algorithm for Bethlem myopathy

OBJECTIVE

Mutations in COL6A1, COL6A2, and COL6A3, the genes that encode the extracellular matrix component collagen VI, lead to Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). Unlike UCMD, BM is difficult to diagnose because of its clinical overlap with other contractural phenotypes and the lack of sensitivity of standard muscle biopsy immunohistochemical diagnostic techniques.

METHODS

We appraised two potential techniques for the diagnosis of BM: dual immunofluorescence (IF) for collagen VI and basal lamina-located perlecan in muscle, and immunofluorescent labeling of collagen VI in skin biopsy-derived fibroblast cultures, which was conducted in 40 patients by blinded investigators and correlated with genetic findings.

RESULTS

Dual IF was indistinguishable from normal controls in most BM patients. However, abnormalities in the IF labeling pattern of collagen VI were detected in more than 78% of genetically confirmed BM patient fibroblast cell lines. In addition, in a group of patients with unknown diagnosis studied prospectively, the fibroblast IF technique was highly predictive of the presence of a COL6A mutation, providing a positive predictive value of 75%, a sensitivity and negative predictive value of 100%, and a specificity of 63%.

CONCLUSIONS

Immunofluorescent labeling of collagen VI in fibroblast cultures is a useful addition to current diagnostic services for Bethlem myopathy (BM). It can be used to guide molecular genetic testing, the gold standard diagnostic technique for BM, in a cost-effective and time-saving manner.

Export of dissolved organic carbon from peatlands under elevated carbon dioxide levels

Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river discharge--cannot offer satisfactory explanations. Here we show that the third proposed mechanism, namely shifting trends in the proportion of annual rainfall arriving in summer, is similarly unable to account for the trend. Instead we infer that a previously unrecognized mechanism--carbon dioxide mediated stimulation of primary productivity--is responsible. Under elevated carbon dioxide levels, the proportion of dissolved organic carbon derived from recently assimilated carbon dioxide was ten times higher than that of the control cases. Concentrations of dissolved organic carbon appear far more sensitive to environmental drivers that affect net primary productivity than those affecting decomposition alone.

Total knee arthroplasty for neglected permanent post-traumatic patellar dislocation--case report

Permanent post-traumatic patellar dislocation is a rare entity resulting from recurrent trauma. This uncommon condition is often confused clinically with congenital dislocation of the patella. Treatment options, although not well defined, include observation, various soft tissue and bony procedures for realigning the patella and patellectomy. To our knowledge, this is the first case reporting the use of conventional non-constrained total knee arthroplasty with patellar resurfacing and soft tissue realignment procedure for long-standing patellar dislocation in a single stage. An interesting feature of this case was the patient's ability to function reasonably well for nearly 40 years with a dislocated patella until the development of secondary osteoarthritis, and the surprisingly good recovery after total knee replacement.

Antiviral activity of characterized extracts from echinacea spp. (Heliantheae: Asteraceae) against herpes simplex virus (HSV-I)

Extracts of 8 taxa of the genus Echinacea were found to have antiviral activity against Herpes simplex (HSV) virus Type I in vitro when exposed to visible and UV-A light. n-Hexane extracts of roots containing alkenes and amides were more active in general than ethyl acetate extracts containing caffeic acids. The most potent inhibitors of HSV were E. pallida var. sanguinea crude (70 % ethanol) inflorescence extract (MIC = 0.026 mg/mL), cichoric acid (MIC = 0.045 mg/mL) and Echinacea purpurea n-hexane root extract (MIC = 0.12 mg/mL).

Ultrastructural changes in malignant transformation of oral mucosa

Transmission electron microscopy (EM) has been used to identify the ultrastructural details of normal and cancerous human oral mucosa. However, inconsistent reports of structural descriptions have rendered transmission EM valueless in the diagnosis of oral squamous cell carcinoma (SCC) or as a prognostic indicator. To identify features of dysplasia for diagnostic purposes, normal mucosa, severe dysplasia, oral SCC and normal margin adjacent to oral SCC were used to compare the ultrastructural features of normal and premalignant oral mucosa and oral SCC. The preparatory stages of dehydration, embedding, cutting and positive staining for transmission EM were modified and tested to improve ultrastructural definition. Thin and discontinuous basal laminas were found in mucosa with severe dysplasia and normal margin adjacent to oral SCC. No basal lamina was identified in oral SCC. This study has shown that there are some ultrastructural changes during malignant transformation of oral mucosa. Together with other laboratory investigative techniques, transmission EM may be helpful in detecting malignant changes in oral mucosa.

Ectodysplasin-A1 is sufficient to rescue both hair growth and sweat glands in Tabby mice

Mutations in the human ectodysplasin-A (EDA) are responsible for the most common form of the ectodermal dysplasia and the defective orthologous gene in mice produces the tabby phenotype, suggesting its vital role in the development of hair, sweat glands and teeth. Among several EDA splice isoforms, the most common and the longest EDA splice isoforms, EDA-A1 and EDA-A2, differing by only two amino acids, activate NF-kappaB-promoted transcription by binding to distinct receptors, EDAR and XEDAR. The extent to which any particular isoform is sufficient for the formation of hair, sweat glands or teeth has remained unclear. Here we report that transgenic expression of the mouse EDA-A1 isoform in tabby (EDA-less) males rescued development of several skin appendages. The transgenic tabby mice showed almost complete restoration of hair growth, dermal ridges, sweat glands and molars. The number of hair follicles in the transgenic mice is the same as in wild-type; though the development of follicles and associated glands varies from indistinguishable from wild-type to smaller and/or only partially formed. These results suggest that the other EDA isoforms may not be absolutely required for skin appendage formation, but consistent with distinctive temporal and spatial expression of the EDA-A2 isoform, are likely required for appropriate timing and completeness of development. Our data provide the first direct physiological evidence that EDA-A1 is a key regulator of hair follicle and sweat gland initiation; its soluble ligand form could aid in deriving therapeutic reagents for conditions affecting hair and sweat gland formation.

HIV protease inhibitor substitution in patients with lipodystrophy: a randomized, controlled, open-label, multicentre study

BACKGROUND

Lipodystrophy, dyslipidaemia and insulin resistance often complicate protease inhibitor-containing antiretroviral therapy. The aims of this study were to determine if these are reversible with continued HIV suppression following protease inhibitor substitution.

METHODS

Eighty-one HIV protease inhibitor recipients (78 male; mean antiretroviral therapy, 55 months) with predominant peripheral lipoatrophy, HIV RNA < 400 copies/ml plasma for at least the preceding 6 months, and no prior abacavir, non-nucleoside analogue or adefovir therapy were randomized 3 : 2 to continue nucleoside analogues and substitute protease inhibitor(s) with abacavir, nevirapine, adefovir and hydroxyurea (n = 49) or to continue all therapy (n = 32) with an option to switch at week 24. The primary endpoints were total body fat and HIV RNA at week 24. Other assessments were regimen safety, regional body composition, metabolic parameters, quality of life, and CD4 T-lymphocyte counts to week 48.

RESULTS

There was a greater decline in total body fat in the switch group than in the continue group (-1.6 and -0.4 kg, respectively at week 24; P = 0.006). This comprised greater declines in limb and subcutaneous abdominal fat, and in intra-abdominal fat of patients with moderate or severe abdominal fat accumulation. Viral suppression was similar, despite 18 (37%) switch group patients ceasing at least one study drug by week 24 because of adverse events. Total cholesterol and triglycerides declined more in the switch group (both P < 0.002). High density lipoprotein cholesterol increased significantly in both groups at week 48 (P < 0.02). There was no change for any glycaemic parameter.

CONCLUSIONS

In predominantly lipoatrophic patients, switching from HIV protease inhibitor therapy lead to improved lipids and less intra-abdominal fat, but also to less peripheral fat, and had minimal effect on insulin resistance. Virological control in these heavily pretreated patients was unaffected, despite frequent switch drug cessations.

Extent of linkage disequilibrium between the androgen receptor gene CAG and GGC repeats in human populations: implications for prostate cancer risk

While studies have implicated alleles at the CAG and GGC trinucleotide repeats of the androgen receptor gene with high-grade, aggressive prostate cancer disease, little is known about the normal range of variation for these two loci, which are separated by about 1.1 kb. More importantly, few data exist on the extent of linkage disequilibrium (LD) between the two loci in different human populations. Here we present data on CAG and GGC allelic variation and LD in six diverse populations. Alleles at the CAG and GGC repeat loci of the androgen receptor were typed in over 1000 chromosomes from Africa, Asia, and North America. Levels of linkage disequilibrium between the two loci were compared between populations. Haplotype variation and diversity were estimated for each population. Our results reveal that populations of African descent possess significantly shorter alleles for the two loci than non-African populations (P<0.0001). Allelic diversity for both markers was higher among African Americans than any other population, including indigenous Africans from Sierra Leone and Nigeria. Analysis of molecular variance revealed that approx. 20% of CAG and GGC repeat variance could be attributed to differences between the populations. All non-African populations possessed the same common haplotype while the three populations of African descent possessed three divergent common haplotypes. Significant LD was observed in our sample of healthy African Americans. The LD observed in the African American population may be due to several reasons; recent migration of African Americans from diverse rural communities following urbanization, recurrent gene flow from diverse West African populations, and admixture with European Americans. This study represents the largest genotyping effort to be performed on the two androgen receptor trinucleotide repeat loci in diverse human populations.

Human reserve pluripotent mesenchymal stem cells are present in the connective tissues of skeletal muscle and dermis derived from fetal, adult, and geriatric donors

This study details the profile of 13 cell surface cluster differentiation markers on human reserve stem cells derived from connective tissues. Stem cells were isolated from the connective tissues of dermis and skeletal muscle derived from fetal, mature, and geriatric humans. An insulin/dexamethasone phenotypic bioassay was used to determine the identity of the stem cells from each population. All populations contained lineage-committed myogenic, adipogenic, chondrogenic, and osteogenic progenitor stem cells as well as lineage-uncommitted pluripotent stem cells capable of forming muscle, adipocytes, cartilage, bone, fibroblasts, and endothelial cells. Flow cytometric analysis of adult stem cell populations revealed positive staining for CD34 and CD90 and negative staining for CD3, CD4, CD8, CD11c, CD33, CD36, CD38, CD45, CD117, Glycophorin-A, and HLA DR-II.

Clonogenic analysis reveals reserve stem cells in postnatal mammals: I. Pluripotent mesenchymal stem cells

Clonal populations of lineage-uncommitted pluripotent mesenchymal stem cells have been identified in prenatal avians and rodents. These cells reside in the connective tissue matrices of many organs and tissues. They demonstrate extended capabilities for self-renewal and the ability to differentiate into multiple separate tissues within the mesodermal germ line. This study was designed to determine whether such cells are present in the connective tissues of postnatal mammals. This report describes a cell clone derived by isolation from postnatal rat connective tissues, cryopreservation, extended propagation, and serial dilution clonogenic analysis. In the undifferentiated state, this clone demonstrates a high nuclear-to-cytoplasmic ratio and extended capacity for self-renewal. Subsequent morphological, histochemical, and immunochemical analysis after the induction of differentiation revealed phenotypic markers characteristic of multiple cell types of mesodermal origin, such as skeletal muscle, smooth muscle, fat cells, cartilage, and bone. These results indicate that this clone consists of pluripotent mesenchymal stem cells. This report demonstrates that clonal populations of reserve stem cells are present in mammals after birth. Potential roles for such cells in the maintenance, repair, and regeneration of mesodermal tissues are discussed.

Isolation and characterization of canine hematopoietic progenitor cells

The purpose of this study was to purify and characterize canine hematopoietic progenitor cells for surface antigen phenotype and reconstitution ability. Canine hematopoietic progenitor cells were isolated by density gradient sedimentation, lineage depletion with monoclonal antibodies, and fluorescence-activated cell sorting (FACS) for selection of cells with low-forward and right-angle scatter that were rhodamine 123 (Rh-123)(dull). Isolated cells were characterized for expression of CD34, c-kit, and Flt-3. A canine/murine xenograft model and a mixed-chimerism assay were used to examine the in vivo proliferative potential of isolated cells. The lineage-positive (Lin(+)) cells represented 80 +/- 11% (n = 22) of the input mononuclear cells. Lineage depletion resulted in a fourfold increase in colony-forming unit granulocyte/monocyte (CFU-GM), a 2.5-fold increase in burst-forming unit-erythroid (BFU-E), and a twofold increase in the number of Rh-123(dull) cells over nonlineage-depleted bone marrow mononuclear cells (BMMCs). Lineage depletion led to a 2.7-fold enrichment of CD34 cells, a 10.4-fold enrichment of c-kit cells, and a 10.8-fold enrichment of CD34/c-kit(+1) cells over total BMMCs. Nineteen percent of lineage-negative (Lin(-)) cells were positive for Flt-3. Injection of canine cells into irradiated (400 rads) NOD/SCID mice resulted in the detection of canine CD45(+) cells with BMMCs, Lin(-) cells, or Rh-123(dull) cells. Transplantation of purified Lin(-) cells in dog leukocyte antigen-matched littermates resulted in low-level engraftment for at least 10 weeks. The development of methods for purification and characterization of canine hematopoietic progenitor cells should enhance the utilization of the canine model for a variety of experimental and therapeutic purposes.

Gender differences, physiological arousal and the role of winning in fruit machine gamblers

AIMS

To examine gender differences in changes in physiological arousal as indexed by heart rate during fruit machine gambling while controlling for the confounding effect of movement and as a function of winning and losing, and to examine relationships between sensation-seeking, self-reported arousal during gambling, heart rate during gambling and loss of control of gambling behaviour. SAMPLE, DESIGN AND MEASUREMENTS: Heart rate and subjective arousal were recorded in a sample of 22 male and 20 female fruit machine players before, during and after the gambling process. At baseline measures were taken of sensation seeking, self-reported arousal during gambling and loss of control of gambling. A simulation of the behaviour used to operate fruit machines was used during baseline measurement.

FINDINGS

Significant increases in heart-rate over movement controlled baselines were observed within participants during gambling. However, for the losing group these differences were slight compared to the increases found when participants won during play. Furthermore, winning/losing was the only variable among a range of variables which was a significant predictor of heart-rate increase during play over a baseline control. Additionally HR levels of males and females behaved the same way in relation to the manipulations. Significant correlations between HR during play and the measures of both subjective arousal and sensation seeking were also present.

CONCLUSIONS

Winning during gambling is essential in order to maintain increased HR levels over baseline after play. Subjective arousal and sensation seeking may be predictors of levels of arousal experienced during play.

Prospective controlled study of carotid endarterectomy with hemashield patch: is it thrombogenic?

The use of patch angioplasty after carotid endarterectomy (CEA) has been shown to have superior results to CEA with primary closure. Polytetrafluoroethylene (PTFE) patches have been shown to have comparable results to autogenous vein patching; however, PTFE has the disadvantage of prolonged hemostasis time. Therefore, many surgeons are using collagen-impregnated Dacron patches (Hemashield[HP]). We believe this is the first prospective controlled study of the use of HP in carotid endarterectomy. This study included 144 consecutive patients who had 151 CEAs with HP. Postoperative duplex ultrasounds were done at 1 month and every 6 months thereafter. The mean follow-up was 12 months (range: 1-30 months). Indications for CEA included symptomatic (64%) and asymptomatic (36%) stenoses. The overall incidence of ipsilateral stroke was 5% (4% perioperative), with a combined TIA and stroke rate of 12%. Incidence of > or =50% recurrent stenosis was 21% (7% symptomatic TIA/stroke) and > or =80% recurrent stenosis was 9%. Kaplan-Meier analysis showed that at 1 year and 2.5 years freedom from > or =50% recurrent stenosis was 78% and 57%, respectively, freedom from > or =80% recurrent stenosis was 92% and 77%, respectively, and a stroke-free survival rate of 94% and 72%, respectively. Women had a 22% and men a 14% recurrent stenosis rate (p=0.04). There was no correlation between other specific risk factors and recurrent stenosis except for hypertension (33% vs 12%, p=0.003). The authors concluded that CEA with HP had a higher incidence of recurrent stenosis (21%), and a higher perioperative stroke rate (4%) after a mean follow-up of 12 months than previously reported using PTFE or saphenous vein patching (2% and 9% recurrent stenosis rates, respectively, and 1% and 0% perioperative stroke rates, respectively after a mean follow-up of 30 months). This raises the question as to whether this patch is thrombogenic in this location. Therefore, a randomized controlled trial comparing this patch with other patches (PTFE or vein) is warranted.

Integration of cytogenetic landmarks into the draft sequence of the human genome

We have placed 7,600 cytogenetically defined landmarks on the draft sequence of the human genome to help with the characterization of genes altered by gross chromosomal aberrations that cause human disease. The landmarks are large-insert clones mapped to chromosome bands by fluorescence in situ hybridization. Each clone contains a sequence tag that is positioned on the genomic sequence. This genome-wide set of sequence-anchored clones allows structural and functional analyses of the genome. This resource represents the first comprehensive integration of cytogenetic, radiation hybrid, linkage and sequence maps of the human genome; provides an independent validation of the sequence map and framework for contig order and orientation; surveys the genome for large-scale duplications, which are likely to require special attention during sequence assembly; and allows a stringent assessment of sequence differences between the dark and light bands of chromosomes. It also provides insight into large-scale chromatin structure and the evolution of chromosomes and gene families and will accelerate our understanding of the molecular bases of human disease and cancer.

Factors affecting metamotivational reversals during motor task performance

Reversal theory proposes that the individual's psychological state constantly switches between metamotivational state pairs (such as Apter's 1982 telic-paratelic pair). Three factors are thought to affect reversals: frustration, contingent event, and satiation. Only a few studies have directly investigated these factors in sports contexts, and evidence is needed to assess support for these factors. In a laboratory setting, 24 participants performed a telic and a paratelic version of a dart-throwing task for 10 min. Participants were free to change from one task version to another as they wished, and reasons for any task changes were solicited. Task changes, indicative of reversals, were observed in 11 participants, and these were reported as due to satiation or frustration but not to contingent events. These findings may inform the structure of sessions on skill development but require confirmation in actual sports contexts.

Femoral morphology and cross-sectional geometry of adult myostatin-deficient mice

GDF-8, also known as myostatin, is a member of the transforming growth factor-beta (TGF-beta) superfamily of secreted growth and differentiation factors that is expressed in vertebrate skeletal muscle. Myostatin functions as a negative regulator of skeletal muscle growth and myostatin null mice show a doubling of muscle mass compared with normal mice. We examined femoral morphology of adult myostatin-deficient mice to assess the effects of muscle fiber hypertrophy and hyperplasia on bone shape and cross-sectional geometry. Femora of age- and weight-matched adult mice homozygous for the disrupted myostatin sequence were compared with those of wild-type controls (n = 8 per group). Results show that, as was the case in previous studies, myostatin null mice have hindlimb muscle masses that are approximately double those of controls. Myostatin-deficient mice exhibit third trochanters that are significantly larger than those of controls, whereas the femoral midshafts of the control and experimental mice do not differ significantly from one another in cortical area, bending moment of inertia, and polar moment of inertia. Our findings indicate that the increased muscle mass of myostatin-deficient mice primarily affects sites of muscle insertion, but does not induce additional cortical bone deposition in the diaphysis relative to controls. We therefore conclude that the expanded third trochanters of myostatin-deficient subjects result from tendon and Sharpey fiber expansion associated with muscle growth rather than cortical bone deposition in response to increased levels of mechanical stress.

Effects of a medicine review and education programme for older people in general practice

AIMS

To determine whether a medicine review and education programme influences the compliance and knowledge of older people in general practice.

METHODS

Older people taking at least three medicines were randomly allocated to a control or intervention group. Both groups received three visits from a clinical pharmacist: Visit 1: Assessment and patients' medicines rationalized in intervention group. Visit 2: Intervention group given medicines education. Visit 3: Knowledge and compliance in both groups assessed by structured questionnaire

RESULTS

Compliance in the intervention group was 91.3%, compared with 79.5% in the control group (P < 0.0001). The number of intervention group patients correctly understanding the purpose of their medicines increased from 58% to 88% on the second visit, compared with 67% to 70% in the control group (P < 0.0005).

CONCLUSIONS

A general practice based medication review and education programme improved medicine compliance and knowledge of older people in the short term.

A randomised, open-label comparison of three highly active antiretroviral therapy regimens including two nucleoside analogues and indinavir for previously untreated HIV-1 infection: the OzCombo1 study

BACKGROUND

Highly active antiretroviral therapy (HAART) including two nucleoside analogues and a potent protease inhibitor is standard of care initial therapy for HIV-infected adults. The best-tolerated and most potent initial HAART regimen is unknown and was investigated in this study.

METHODS

One hundred and nine HIV-infected adults with no prior antiretroviral therapy, and CD4 lymphocyte counts < 500 x 10(6) cells/l or plasma HIV RNA > 30,000 copies/ml were randomized to zidovudine-lamivudine-indinavir (ZDV-3TC-IDV), stavudine-lamivudine-indinavir (d4T-3TC-IDV) or stavudine-didanosine-indinavir (d4T-ddI-IDV) for 52 weeks. The primary endpoints were plasma HIV RNA and drug-related adverse events. Other assessments were overall safety, adherence and adverse events, CD4 lymphocyte counts, cutaneous delayed type hypersensitivity (DTH) responses and quality of life (Euroqol).

RESULTS

Only 58% patients had HIV RNA < 50 copies/ml plasma at 12 months, with no significant difference between the three regimes (P = 0.34). Drug-related adverse events sufficiently severe to warrant drug discontinuation were less common (P = 0.06) in patients receiving d4T-3TC-IDV (18%) than in those receiving ZDV-3TC-IDV (34%) or d4T-ddI-IDV (41%). The percentages of patients who remained on their assigned therapy with plasma HIV RNA < 50 copies/ml at 52 weeks were 60% with d4T-3TC-IDV, 53% with ZDV-3TC-IDV and 35% with d4T-ddI-IDV. Virological failure at 52 weeks was more likely in those whose adherence was estimated to be < 100% in the first 4 weeks of therapy (P = 0.02), but not in those who developed grade 3 or 4 drug-related adverse events. At 52 weeks, the mean CD4 lymphocyte count increase was 200 x 10(6) cells/l with only 7% of patients having counts lower than at baseline; DTH responses improved but remained clinically impaired in most patients. Quality of life improved significantly in all groups.

CONCLUSIONS

Initial HAART regimens including IDV failed to suppress plasma HIV RNA to < 50 copies/ml in > 40% patients after only 12 months of therapy although there was significant overall improvement immunologically and in quality of life. The type of dual nucleoside combination used was less important in predicting virological failure than was imperfect adherence early in therapy. Consideration should be given to modifying a HAART regimen relatively early in non-adherent patients.

A cluster of pediatric metallic mercury exposure cases treated with meso-2,3-dimercaptosuccinic acid (DMSA)

Nine children and their mother were exposed to vapors of metallic mercury. The source of the exposure appears to have been a 6-oz vial of mercury taken from a neighbor's home. The neighbor reportedly operated a business preparing mercury-filled amulets for practitioners of the Afro-Caribbean religion Santeria. At diagnosis, urinary mercury levels in the children ranged from 61 to 1,213 microg/g creatinine, with a geometric mean of 214.3 microg/m creatinine. All of the children were asymptomatic. To prevent development of neurotoxicity, we treated the children with oral meso-2,3-dimercaptosuccinic acid (DMSA). During chelation, the geometric mean urine level rose initially by 268% to 573.2 microg mercury/g creatinine (p<0.0005). At the 6-week follow-up examination after treatment, the geometric mean urine mercury level had fallen to 102.1 microg/g creatinine, which was 17.8% of the geometric mean level observed during treatment (p<0.0005) and 47.6% of the original baseline level (p<0.001). Thus, oral chelation with DMSA produced a significant mercury diuresis in these children. We observed no adverse side effects of treatment. DMSA appears to be an effective and safe chelating agent for treatment of pediatric overexposure to metallic mercury.

Psychometric evaluation of a questionnaire modified to assess attitudes toward male social workers

The Attitudes Toward Male Nurses Scale was modified and then administered to a stratified-by-sex sample of 149 members of a state chapter of the National Association of Social Workers. Analysis suggests suitable internal consistency for the modified 15-item measure and provides empirical support for the scale's convergent-discriminant validity.

Suppression of microtubule dynamic instability and treadmilling by deuterium oxide

Deuterium oxide (D(2)O) is known to promote the assembly of tubulin into microtubules in vitro, to increase the volume of mitotic spindles and the number and length of spindle microtubules, and to inhibit mitosis. Reasoning that its actions on cellular microtubules could be due to modulation of microtubule dynamics, we examined the effects of replacing H(2)O with D(2)O on microtubule dynamic instability, treadmilling, and steady-state GTPase activity. We found that replacing 50% or more of the H(2)O with D(2)O promoted microtubule polymerization and stabilized microtubules against dilution-induced disassembly. Using steady-state axoneme-seeded microtubules composed of pure tubulin and video microscopy, we found that 84% D(2)O decreased the catastrophe frequency by 89%, the shortening rate by 80%, the growing rate by 50%, and the dynamicity by 93%. Sixty percent D(2)O decreased the treadmilling rate of microtubules composed of tubulin and microtubule-associated proteins by 42%, and 89% D(2)O decreased the steady-state GTP hydrolysis rate by 90%. The mechanism responsible for the ability of D(2)O to stabilize microtubule dynamics may involve enhancement of hydrophobic interactions in the microtubule lattice and/or the substitution of deuterium bonds for hydrogen bonds.

Development of a prostate cDNA microarray and statistical gene expression analysis package

A cDNA microarray comprising 5184 different cDNAs spotted onto nylon membrane filters was developed for prostate gene expression studies. The clones used for arraying were identified by cluster analysis of > 35 000 prostate cDNA library-derived expressed sequence tags (ESTs) present in the dbEST database maintained by the National Center for Biotechnology Information. Total RNA from two cell lines, prostate line 8.4 and melanoma line UACC903, was used to make radiolabeled probe for filter hybridizations. The absolute intensity of each individual cDNA spot was determined by phosphorimager scanning and evaluated by a bioinformatics package developed specifically for analysis of cDNA microarray experimentation. Results indicated 89% of the genes showed intensity levels above background in prostate cells compared with only 28% in melanoma cells. Replicate probe preparations yielded results with correlation values ranging from r = 0.90 to 0.93 and coefficient of variation ranging from 16 to 28%. Findings indicate that among others, the keratin 5 and vimentin genes were differentially expressed between these two divergent cell lines. Follow-up northern blot analysis verified these two expression changes, thereby demonstrating the reliability of this system. We report the development of a cDNA microarray system that is sensitive and reliable, demonstrates a low degree of variability, and is capable of determining verifiable gene expression differences between two distinct human cell lines. This system will prove useful for differential gene expression analysis in prostate-derived cells and tissue.

Low HDL cholesterol, aggression and altered central serotonergic activity

Many studies support a significant relation between low cholesterol levels and poor impulse, aggression and mood control. Evidence exists also for a causal link between low brain serotonin (5-HT) activity and these behaviors. Mechanisms linking cholesterol and hostile or self-destructive behavior are unknown, but it has been suggested that low cholesterol influences 5-HT function. This study was designed to explore the relationship between plasma cholesterol, measures of impulsivity and aggression, and indices of 5-HT function in personality disordered cocaine addicts. Thirty-eight hospitalized male patients (age 36.8+/-7.1) were assessed with the DSM-III-R, the Buss-Durkee Hostility Inventory (BDHI), the Barratt Impulsiveness Scale (BIS) and the Brown-Goodwin Assessment for Life History of Aggression. Fasting basal cholesterol (total, LDL and HDL) was determined 2 weeks after cocaine discontinuation. On the same day 5-HT function was assessed by neuroendocrine (cortisol and prolactin) and psychological (NIMH and 'high' self-rating scales) responses following meta-chlorophenylpiperazine (m-CPP) challenges. Reduced neuroendocrine responses, 'high' feelings and increased 'activation-euphoria' following m-CPP have been interpreted as indicating 5-HT alterations in a variety of psychiatric conditions. Significantly lower levels of HDL cholesterol were found in patients who had a history of aggression (P=0.005). Lower levels of HDL cholesterol were also found to be significantly associated with more intense 'high' and 'activation-euphoria' responses as well as with blunted cortisol responses to m-CPP (P=0.033, P=0.025 and P=0.018, respectively). This study gives further support to existing evidence indicating that in some individuals, the probability of exhibiting impulsive and violent behaviors may be increased when cholesterol is low. It also suggests that low cholesterol and alterations in 5-HT activity may be causally related.

Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling

Diffuse large B-cell lymphoma (DLBCL), the most common subtype of non-Hodgkin's lymphoma, is clinically heterogeneous: 40% of patients respond well to current therapy and have prolonged survival, whereas the remainder succumb to the disease. We proposed that this variability in natural history reflects unrecognized molecular heterogeneity in the tumours. Using DNA microarrays, we have conducted a systematic characterization of gene expression in B-cell malignancies. Here we show that there is diversity in gene expression among the tumours of DLBCL patients, apparently reflecting the variation in tumour proliferation rate, host response and differentiation state of the tumour. We identified two molecularly distinct forms of DLBCL which had gene expression patterns indicative of different stages of B-cell differentiation. One type expressed genes characteristic of germinal centre B cells ('germinal centre B-like DLBCL'); the second type expressed genes normally induced during in vitro activation of peripheral blood B cells ('activated B-like DLBCL'). Patients with germinal centre B-like DLBCL had a significantly better overall survival than those with activated B-like DLBCL. The molecular classification of tumours on the basis of gene expression can thus identify previously undetected and clinically significant subtypes of cancer.

What kinds of people should we create?

The advent of genetic engineering will give people the power to design the members of the succeeding generation, and thus will render practical the issue how such a power ought to be exercised. Here I address that issue in a general way. I point out that the aim of making future people better adapted to the modern social environment is implicitly circular, since the natures of the peoples themselves will determine the nature of the social environment. I claim that the human property the enhancement of which would do most to enrich experience is intelligence; accordingly increased intelligence should be a primary aim of genetic designers. The tendency to feel pain should be attenuated, as positive motivation is substituted for negative (to some extent). People should be designed so as to be motivated more by reason than by any non-rational drives (though rational motivation may still involve pleasure and pain). The sex drive, having outlived its usefulness, will probably be replaced by some other source of pleasure. As a side effect of these changes in people, the arts and social sciences will be transformed beyond recognition.

Coccygeal muscle injury in English Pointers (limber tail)

A condition colloquially referred to as "limber tail" and "cold tail" is familiar to people working with hunting dogs, primarily Pointers and Labrador Retrievers. The typical case consists of an adult dog that suddenly develops a flaccid tail. The tail either hangs down from the tail base or is held out horizontally for several inches from the tail base and then hangs straight down or at some degree below horizontal. Initially, the hair on the dorsal aspect of the proximal tail may be raised and dogs may resent palpation of the area 3-4 inches (8-10 cm) from the tail base. Most dogs recover spontaneously within a few days to weeks. Anecdotal reports suggest that anti-inflammatory drugs administered within 24 hours after onset hasten recovery. Less than one half of affected dogs experience a recurrence. Affected Pointers almost always have a history of prolonged cage transport, a hard workout the previous day, or exposure to cold or wet weather Most owners and trainers familiar with the condition do not seek veterinary assistance. In cases where people are not familiar with this disease, other conditions such as a fracture, spinal cord disease, impacted anal glands, or prostatic disease have been incorrectly diagnosed. We examined 4 affected Pointers and found evidence of coccygeal muscle damage, which included mild elevation of creatine kinase early after onset of clinical signs, needle electromyographic examination showing abnormal spontaneous discharges restricted to the coccygeal muscles several days after onset, and histopathologic evidence of muscle fiber damage. Specific muscle groups, namely the laterally positioned intertransversarius ventralis caudalis muscles, were affected most severely. Abnormal findings on thermography and scintigraphy further supported the diagnosis.

Serotonergic function in cocaine addicts: prolactin responses to sequential D,L-fenfluramine challenges

BACKGROUND

Preclinical studies have shown that cocaine produces alterations in serotonergic function but our knowledge of the serotonergic alterations due to cocaine abuse in humans is still fragmentary. We therefore assessed the central serotonergic responsivity of cocaine addicts and control subjects by neuroendocrine challenges with the serotonin releaser and reuptake inhibitor D,L-fenfluramine (FEN).

METHODS

Plasma prolactin levels following a 60 mg oral dose of FEN and placebo were studied in 25 hospitalized male cocaine addicts and 13 healthy male subjects. Control subjects underwent one set of FEN/placebo challenges and cocaine addicts two sets of challenges, during the first and third weeks following cocaine discontinuation. Patients were divided into two subgroups as a function of presence (FH+) and absence (FH-) of a paternal history of substance abuse. The following comparisons were made: 1) Control subjects versus entire patient group and versus patient subgroups; 2) entire patient group and patient subgroups responses to first versus second challenges; 3) FH+ versus FH- patients' early responses and FH+ versus FH- patients' late responses.

RESULTS

The prolactin responses to FEN increased significantly in the entire patient group as time following cocaine discontinuation increased. The FH+ patients had significantly blunted early responses by comparison with FH- patients and control subjects. There was a more pronounced rebound of the responses of FH+ patients by comparison with those of FH- patients. As a result, comparisons of the late responses of FH+ and FH- patients and of FH+ patients and control subjects became nonsignificant.

CONCLUSIONS

Cocaine use appears to have an effect on the serotonergic mechanisms mediating prolactin release in humans. In the present study, this effect was more pronounced in a subgroup of patients with a paternal history of alcoholism or drug abuse. The greater blunting of the prolactin response observed within days of cocaine discontinuation followed by a greater rebound of this response 2 weeks later could indicate an increased vulnerability to the disruptive effects of cocaine in these patients.

The transcriptional program in the response of human fibroblasts to serum

The temporal program of gene expression during a model physiological response of human cells, the response of fibroblasts to serum, was explored with a complementary DNA microarray representing about 8600 different human genes. Genes could be clustered into groups on the basis of their temporal patterns of expression in this program. Many features of the transcriptional program appeared to be related to the physiology of wound repair, suggesting that fibroblasts play a larger and richer role in this complex multicellular response than had previously been appreciated.