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Biomedical subjects

P Rogers

Publications and source records attributed to P Rogers.

At least 37 records · Page 2Linked to original sources

Phylogenetic structure of unusual aquatic microbial formations in Nullarbor caves, Australia.

The nature of unusual aquatic microbial formations in flooded passages of cave systems in the Nullarbor region of Australia was investigated using electron microscopy and DNA analysis. The caves are located in a semiarid region but intersect the watertable at depths of approximately 100 m below the surface. Throughout submerged portions of the caves divers have noted the presence of unusual microbial formations. These 'microbial mantles' comprise sheets or tongues of mucoid material in which small crystals are embedded. Examination of the biomass revealed it to be primarily composed of densely packed, unbranched filaments, together with spherical-, rod- and spiral-shaped cells, and microcrystals of calcite in a mucoid matrix. Molecular phylogenetic analysis of the community structure revealed approximately 12% of clones showed high similarity to autotrophic nitrite-oxidizing bacteria (Nitrospira moscoviensis). The remainder of the clones exhibited a high proportion of phylogenetically novel sequence types. Chemical analysis of water samples revealed high levels of sulphate and nitrate together with significant nitrite. The community structure, the presence of nitrite in the water, and the apparent absence of aquatic macrofauna, suggest these microbial structures may represent biochemically novel, chemoautotrophic communities dependent on nitrite oxidation.

Australia↗

Dietary protein and soluble fiber reduce ambulatory blood pressure in treated hypertensives.

In population studies, higher blood pressure has been associated with lower intake of protein and, possibly, lower fiber consumption. In the present randomized controlled trial, we sought to determine whether dietary protein and fiber had additive effects on blood pressure reduction in hypertensives. Treated hypertensive patients changed for 4 weeks (familiarization) to a diet low in protein (12.5% energy) and fiber (15 g/d). Patients (n=41) were then randomized to 1 of 4 groups in an 8-week factorial study of parallel design in which they continued the low-protein, low-fiber diet alone or had supplements of soy protein to increase protein intake to 25% energy, of psyllium to provide an additional 12 g soluble fiber/d, or of both protein and fiber. The 24-hour ambulatory blood pressure was compared from the end of familiarization to the end of intervention. In the 36 subjects who provided complete data, protein and fiber had significant additive effects to lower 24-hour and awake systolic blood pressure. Relative to control subjects, the net reduction in 24-hour systolic blood pressure was 5.9 mm Hg with fiber and with protein. Findings were independent of age, gender, and change in weight, alcohol intake, or urinary sodium and potassium. Relative to reduced fiber and protein intake, dietary protein and soluble fiber supplements lower blood pressure additively in hypertensives. These findings have important implications for the prevention and management of hypertension, particularly in populations in which high blood pressure is prevalent in association with diets low in protein, fiber, or both.

Blood Pressure↗

Common iliac artery access during endovascular thoracic aortic repair facilitated by a transabdominal wall tunnel.

PURPOSE: To describe a technique for common iliac artery (CIA) access during endovascular aortic aneurysm repair when unfavorable angulation between the CIA and the delivery sheath precludes direct arterial access. TECHNIQUE: After retroperitoneal exposure of the CIA, a puncture site is chosen inferolateral to the surgical incision, and an 18-G trocar/cannula is advanced in alignment with the CIA through the anterior abdominal wall or skin of the upper thigh into the retroperitoneal space. Serial dilatation is performed over a guidewire placed through the cannula to create the subcutaneous tract. The trocar/cannula is replaced over the wire, and the CIA is punctured under direct vision. The guidewire is then advanced into the proximal aorta. A CIA arteriotomy is performed and the delivery system introduced over the guidewire through the tunnel into the iliac artery. CONCLUSIONS: Retroperitoneal exposure of the CIA with tunneled transabdominal wall delivery of the stent-graft avoids both external iliac artery injury and creation of a temporary access conduit in patients with iliac tortuosity and/or occlusive disease.

Abdominal Muscles↗

Improved laser-assisted vascular tissue fusion using light-activated surgical adhesive in a porcine model.

Newly developed light-activated surgical adhesives have been investigated as a substitute to traditional protein solders for vascular tissue fusion without the need for sutures. Porcine carotid arteries (n = 6) and femoral arteries (n = 6) were exposed, and an incision was made in the arterial walls using a 16G needle. The surgical adhesive, composed of a poly(L-lactic-co-glycolic acid) scaffold doped with the traditional protein solder mix of porcine serum albumin and indocyanine green dye, was used to close the incisions in conjunction with an 805 nm diode laser. Blood flow was restored to the vessels immediately after the procedure and the incision sites were checked for patency. The new adhesives were flexible enough to be wrapped around the vessels while their solid nature avoided the problems associated with "runaway" of the less viscous liquid protein solders widely used by researchers. The strength and hemostatic abilities of the new surgical adhesives were evaluated in the context of arterial pressure, persistence of hemostasis and presence of any inflammatory reaction after 3 days. After this evaluation period, the surgical procedure was repeated on the carotid arteries (n = 6) and femoral arteries (n = 6) of three additional animals that had been heparinized prior to surgery to closer approximate the conditions seen in a typical vascular surgical setting. The patency rate of both the unheparinized and heparinized vessels was 100% at 3 days post-operative with evidence of intraluminal thrombosis seen in only one of the repaired vessels. The adhesive technique also compared favorably with a previous study conducted using conventional suture techniques. Repairs formed with the adhesive technique were achieved more rapidly than suturing, and acute leakage was observed less frequently. Finally, the adhesive technique produced better histology than the suture technique, suggesting that it has great promise as an alternative to suturing. These initial results indicate that laser-assisted vascular repair using the new adhesives is safe, easy to perform, and contrary to conventional suturing, provides an immediate leak-free closure. In addition, the flexible and moldable nature of the new adhesives allows them to be tailored to a wide range of tissue geometries, thus greatly improving the clinical applicability of laser-assisted tissue repair.

Animals↗

BMPR2 haploinsufficiency as the inherited molecular mechanism for primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is a potentially lethal disorder, because the elevation of the pulmonary arterial pressure may result in right-heart failure. Histologically, the disorder is characterized by proliferation of pulmonary-artery smooth muscle and endothelial cells, by intimal hyperplasia, and by in situ thrombus formation. Heterozygous mutations within the bone morphogenetic protein type II receptor (BMPR-II) gene (BMPR2), of the transforming growth factor beta (TGF-beta) cell-signaling superfamily, have been identified in familial and sporadic cases of PPH. We report the molecular spectrum of BMPR2 mutations in 47 additional families with PPH and in three patients with sporadic PPH. Among the cohort of patients, we have identified 22 novel mutations, including 4 partial deletions, distributed throughout the BMPR2 gene. The majority (58%) of mutations are predicted to lead to a premature termination codon. We have also investigated the functional impact and genotype-phenotype relationships, to elucidate the mechanisms contributing to pathogenesis of this important vascular disease. In vitro expression analysis demonstrated loss of BMPR-II function for a number of the identified mutations. These data support the suggestion that haploinsufficiency represents the common molecular mechanism in PPH. Marked variability of the age at onset of disease was observed both within and between families. Taken together, these studies illustrate the considerable heterogeneity of BMPR2 mutations that cause PPH, and they strongly suggest that additional factors, genetic and/or environmental, may be required for the development of the clinical phenotype.

Adolescent↗

Intranasal immunization with HIV reverse transcriptase: effect of dose in the induction of helper T cell type 1 and 2 immunity.

HIV reverse transcriptase (RT) is immunologically recognized by the host after natural infection with HIV. To study the immune response to this nonenvelope protein and the effect of the antigen dose and the immunization route on the differential induction of cellular or humoral responses, CB6F1 mice were immunized intranasally with various doses of recombinant RT (0.025-25 microg/dose) in the presence of the mucosal adjuvant cholera toxin (CT). An antigen-specific, dose-dependent, in vitro proliferative response was observed in splenic cells from all mouse groups immunized with RT and CT. Proliferative responses in salivary gland-associated lymph node (SGALN) cells from the same mice were detected only with higher antigen dose immunizations (2.5, 25 microg/dose). IFN-gamma, a Th1-type cytokine, was detected in RT-stimulated culture supernatants from splenic and SGALN cells from all groups of mice immunized with RT and CT in a dose-dependent fashion. IL-4, a Th2-type cytokine, was detected in RT-stimulated culture supernatants from splenic and SGALN cells from mice immunized with higher doses of RT and CT. RT-specific IgG2a, a Th1-type-related antibody, was detected consistently in sera from all animals immunized with RT and CT and was predominant in mice immunized with lower antigen doses (0.025, 0.25 microg/dose). RT-specific IgG1, a Th2-type-related antibody, was detected consistently in mice immunized with higher antigen doses and was predominant in these groups. These studies demonstrate the immunogenicity of recombinant RT and the effect of the antigen dose in the induction of Th1-type and Th2-type immune responses after mucosal immunization.

AIDS Vaccines↗

Randomized trial of the effects of cholesterol-lowering dietary treatment on psychological function.

PURPOSE: Epidemiological studies have suggested that cholesterol lowering could affect psychological functioning. This study was designed to test whether cholesterol-lowering diets adversely affect mood and cognitive function.5.2 mM [198 mg/dL]) to either a low-fat diet, a Mediterranean diet, or a waiting-list control. Cholesterol levels, psychological well-being (depression, anxiety, hostility), and cognitive function were assessed at baseline, 6 weeks, and 12 weeks. RESULTS: Total serum cholesterol levels fell significantly more in the intervention groups (8.2% reduction) than in the control group (P <0.001). All three groups showed a modest improvement in psychological well-being during the 12-week treatment period, but there were no differences among the groups. There were no between-group differences on three measures of cognitive function, but for a fourth measure, which involved the task with the greatest processing load, the two intervention groups did significantly worse (P <0.001) than the control group. The change in performance was correlated with the change in total serum cholesterol level (r = 0. 21, P = 0.01). CONCLUSIONS: Two dietary interventions that successfully lowered serum cholesterol levels had no adverse effect on mood. There was some evidence for a relative impairment in cognitive function in the treated groups in one of four cognitive tests, but additional studies will be required to determine the relevance of this finding.

Adult↗

Behavioral treatment of PTSD in a perpetrator of manslaughter: a single case study.

Studies of posttraumatic stress disorder (PTSD) have predominantly focused on victims of trauma. Some studies have examined the after-effects of a person's own violent actions in combat or police situations. However, there is a sparsity of literature examining the development of PTSD in convicted perpetrators of violent crime, and there is no literature concerning the treatment of PTSD in such perpetrators. This single-case study presents the outcome of behavioral treatment in one case in which the patient had PTSD consequential to being a perpetrator of manslaughter. The theoretical implications of this case are briefly discussed.

Female↗

BCL-2 family protein expression and platinum drug resistance in ovarian carcinoma.

The expression of the BCL-2 family proteins, BCL-2, BAX, BCL(XL) and BAK have been determined in a panel of 12 human ovarian carcinoma cell lines encompassing a wide range in sensitivity to cisplatin. Whereas BAX, BCL(XL) and BAK levels did not correlate with sensitivity, there was a statistically significant inverse correlation (r = -0.81; P = 0.002) between growth inhibition by cisplatin and BCL-2 levels. In sublines possessing acquired resistance to various platinum-based drugs or across a panel of human ovarian carcinoma xenografts, there was no consistent pattern of BCL-2 expression. Two relatively sensitive lines (A2780 and CH1) have been stably transfected with bcl-2 and bcl(XL) respectively and two relatively resistant lines (A2780cisR and SKOV-3) stably transfected with bax. Overexpression of BCL-2 in A2780 cells led to resistance to cisplatin compared to the vector control when assayed at 48 h post-drug incubation but a significant increase in sensitivity at 96 h. Relative rates of apoptosis at 48- and 96-h post-cisplatin exposure mirrored the growth inhibition. There was no significant difference in sensitivity of the pair of lines by clonogenic assay. No significant changes in chemosensitivity to a variety of DNA-damaging or tubulin-interactive agents were observed in the remaining transfected lines. Taken together, these results suggest that, in human ovarian carcinoma cells, high BCL-2 levels (either naturally occurring or through gene transfection) confers a trend towards sensitivity not resistance to platinum drugs.

Antineoplastic Agents↗

Changing screening strategies for genital chlamydia in family planning clinics: a good public health strategy?

OBJECTIVE: To estimate the prevalence and factors associated with genital chlamydia in 1996 and to evaluate the introduction of restricted screening criteria based on diagnostic testing and prevention of iatrogenic pelvic inflammatory disease in 1997. PATIENTS: Women attending Liverpool family planning clinics. METHOD: Clinical and demographic data were recorded at routine clinic consultations. Data were analyzed using logistic regression. RESULTS: In 1996, a 5.7% (123/2165) chlamydial prevalence was detected. A significantly lower prevalence was observed in the over-25-year-old age group compared to those aged 16-19 years old (p < 0.0001), and in those with an interval of over 11 months since the last new sexual partner compared to those with a new partner in the past 1-3 months (p < 0.05). A significantly higher prevalence was detected in those only presenting with signs of infection alone compared to those presenting with either symptoms or both signs and symptoms of infection (p < 0.05). Those requesting a termination of pregnancy were at higher risk of genital chlamydia than those attending for contraceptive advice (odds ratio 1.97; 95% confidence interval 1.14-3.39). Using the restricted screening criteria, prevalences of 5.4% (78/1438) and 3.7% (60/1641) were found for 1996 and 1997, respectively. Prevalences were significantly higher in 1996 than 1997 when adjusted for the other factors (p < 0.05). CONCLUSION: The study raised awareness of genital chlamydia among women attending family planning clinics and showed that primary care could make a significant contribution to the prevention of chlamydial infection. It is only by initiating intervention strategies in such settings that genital chlamydia will be controlled effectively in the UK.

Adolescent↗

Sporadic primary pulmonary hypertension is associated with germline mutations of the gene encoding BMPR-II, a receptor member of the TGF-beta family.

BACKGROUND: Primary pulmonary hypertension (PPH), resulting from occlusion of small pulmonary arteries, is a devastating condition. Mutations of the bone morphogenetic protein receptor type II gene (BMPR2), a component of the transforming growth factor beta (TGF-beta) family which plays a key role in cell growth, have recently been identified as causing familial PPH. We have searched for BMPR2 gene mutations in sporadic PPH patients to determine whether the same genetic defect underlies the more common form of the disorder. METHODS: We investigated 50 unrelated patients, with a clinical diagnosis of PPH and no identifiable family history of pulmonary hypertension, by direct sequencing of the entire coding region and intron/exon boundaries of the BMPR2 gene. DNA from available parent pairs (n=5) was used to assess the occurrence of spontaneous (de novo) mutations contributing to sporadic PPH. RESULTS: We found a total of 11 different heterozygous germline mutations of the BMPR2 gene in 13 of the 50 PPH patients studied, including missense (n=3), nonsense (n=3), and frameshift (n=5) mutations each predicted to alter the cell signalling response to specific ligands. Parental analysis showed three occurrences of paternal transmission and two of de novo mutation of the BMPR2 gene in sporadic PPH. CONCLUSION: The sporadic form of PPH is associated with germline mutations of the gene encoding the receptor protein BMPR-II in at least 26% of cases. A molecular classification of PPH, based upon the presence or absence of BMPR2 mutations, has important implications for patient management and screening of relatives.

Adolescent↗

Short-course empiric antibiotic therapy for patients with pulmonary infiltrates in the intensive care unit. A proposed solution for indiscriminate antibiotic prescription.

Inappropriate antibiotic use for pulmonary infiltrates is common in the intensive care unit (ICU). We sought to devise an approach that would minimize unnecessary antibiotic use, recognizing that a gold standard for the diagnosis of nosocomial pneumonia does not exist. In a randomized trial, clinical pulmonary infection score (CPIS) (Pugin, J., R. Auckenthaler, N. Mili, J. P. Janssens, R. D. Lew, and P. M. Suter. Diagnosis of ventilator-associated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic "blind" bronchoalveolar lavage fluid. Am. Rev. Respir. Dis. 1991;143: 1121-1129) was used as operational criteria for decision-making regarding antibiotic therapy. Patients with CPIS </= 6 (implying low likelihood of pneumonia) were randomized to receive either standard therapy (choice and duration of antibiotics at the discretion of physicians) or ciprofloxacin monotherapy with reevaluation at 3 d; ciprofloxacin was discontinued if CPIS remained </= 6 at 3 d. Antibiotics were continued beyond 3 d in 90% (38 of 42) of the patients in the standard as therapy compared with 28% (11 of 39) in the experimental therapy group (p = 0.0001). In patients in whom CPIS remained </= 6 at the 3 d evaluation point, antibiotics were still continued in 96% (24 of 25) in the standard therapy group but in 0% (0 of 25) of the patients in the experimental therapy group (p = 0.0001). Mortality and length of ICU stay did not differ despite a shorter duration (p = 0.0001) and lower cost (p = 0.003) of antimicrobial therapy in the experimental as compared with the standard therapy arm. Antimicrobial resistance, or superinfections, or both, developed in 15% (5 of 37) of the patients in the experimental versus 35% (14 of 37) of the patients in the standard therapy group (p = 0.017). Thus, overtreatment with antibiotics is widely prevalent, but unnecessary in most patients with pulmonary infiltrates in the ICU. The operational criteria used, regardless of the precise definition of pneumonia, accurately identified patients with pulmonary infiltrates for whom monotherapy with a short course of antibiotics was appropriate. Such an approach led to significantly lower antimicrobial therapy costs, antimicrobial resistance, and superinfections without adversely affecting the length of stay or mortality.

Aged↗

Targeted deletion of the IgA constant region in mice leads to IgA deficiency with alterations in expression of other Ig isotypes.

A murine model of IgA deficiency has been established by targeted deletion of the IgA switch and constant regions in embryonic stem cells. B cells from IgA-deficient mice were incapable of producing IgA in vitro in response to TGF-beta. IgA-deficient mice expressed higher levels of IgM and IgG in serum and gastrointestinal secretions and decreased levels of IgE in serum and pulmonary secretions. Expression of IgG subclasses was complex, with the most consistent finding being an increase in IgG2b and a decrease in IgG3 in serum and secretions. No detectable IgA Abs were observed following mucosal immunization against influenza; however, compared with those in wild-type mice, increased levels of IgM Abs were seen in both serum and secretions. Development of lymphoid tissues as well as T and B lymphocyte function appeared normal otherwise. Peyer's patches in IgA-deficient mice were well developed with prominent germinal centers despite the absence of IgA in these germinal centers or intestinal lamina propria. Lymphocytes from IgA-deficient mice responded to T and B cell mitogens comparable to those of wild-type mice, while T cells from IgA-deficient mice produced comparable levels of IFN-gamma and IL-4 mRNA and protein. In conclusion, mice with targeted deletion of the IgA switch and constant regions are completely deficient in IgA and exhibit altered expression of other Ig isotypes, notably IgM, IgG2b, IgG3, and IgE, but otherwise have normal lymphocyte development, proliferative responses, and cytokine production.

Animals↗

Non-participation bias in unlinked anonymous HIV-prevalence surveys in England and Wales.

The objective was to assess the potential bias in unlinked anonymous HIV-seroprevalence surveys from objections to specimens being included. Objection rates in seroprevalence surveys were examined. Statistically large clusters of objections were considered to be the result of health care worker behaviour, and were disregarded. Underlying objection rates were estimated from remaining data and compared to seroprevalence. Overall objection rates approached or exceeded seroprevalence in many participating centres. However, underlying objection rates declined with time while prevalences were generally unchanging. Also, underlying rates correlated poorly with observed seroprevalences. Findings were therefore consistent with processes producing the clusters of objections and underlying objection rates independently of serostatus of individuals. Although national seroprevalence estimates produced by the surveys are reasonably free from objection bias, regional seroprevalence estimates outside London remain vulnerable to bias as a result of some centres returning data whose quality cannot be guaranteed.

Bias↗

Option-4 algorithm for Florida pocket depth probe: reduction in the variance of site-specific probeable crevice depth measurements.

Clinical periodontal measurement is plagued by many sources of error which result in aberrant values (outliers). This study sets out to compare probeable crevice depth measurements (PCD) selected by the option-4 algorithm against those recorded with a conventional double-pass method and to quantify any reduction in site-specific PCD variances. A single clinician recorded full-mouth PCD at 1 visit in 32 subjects (mean age 45.5 years) with moderately advanced chronic adult periodontitis. PCD was recorded over 2 passes at 6 sites per tooth with the Florida Pocket Depth Probes, a 3rd generation probe. The option-4 algorithm compared the 1st pass site-specific PCD value (PCD1) to the 2nd pass site-specific PCD value (PCD2) and, if the difference between these values was >1.00 mm, allowed the recording of a maximum of 2 further measurements (3rd and 4th pass measurements PCD3 and PCD4): 4 site-specific measure-meets were considered to be the maximum subject and tissue tolerance. The algorithm selected the 1st 2 measurements whose difference was < or = 1.00 mm (SPCD1 and SPCD2). If no 2 measurements had a difference < or = 1.00 mm, the examiner was required to select the 2 measurements closest to the rules of the algorithm. 4600 sites were available for analysis. 3992 sites (86.8%) required 2 recordings, 564 sites (12.3%) required 3 recordings and 44 sites (1%) required 4 recordings. Correlation coefficients for PCD1 and PCD2 and SPCD1 and SPCD2 were 0.83 and 0.96, respectively (p=0.00). Site-specific variances were calculated for PCD1 and PCD2 and SPCD1 and SPCD2. The mean of the PCD1/PCD2 site-specific variances (A) was 0.41 mm2 (range 0.00 mm2 to 33.62 mm2), whilst the mean of the SPCD1/SPCD2 variances (B) was 0.1 mm2 (range 0.00 mm2 to 2.0 mm2): the respective medians were 0.08 mm2 and 0.02 mm2. The study demonstrated high intra-examiner PCD agreement. The option-4 algorithm produced a reduction of 75.6% in the mean site-specific variance of PCD1/PCD2 (Y) (Y=[(A-B)/A]X 100) and a 75% reduction in the median site-specific variance of PCD1/PCD2.

Adult↗

Left ventricular chamber function during inhaled nitric oxide in patients with dilated cardiomyopathy.

Inhaled nitric oxide is a potent and selective pulmonary vasodilator. However, when used in patients with congestive cardiac failure, the decrease in pulmonary vascular resistance is associated with an increase in pulmonary capillary wedge pressure (PCWP). This study examined load-independent indexes of left ventricular chamber function during inhaled nitric oxide in 10 patients with dilated cardiomyopathy (mean ejection fraction, 30.2+/-7.8%, mean +/- SD). Etiology of cardiomyopathy was idiopathic in six and ischemic in four. Pulmonary hemodynamics in seven patients revealed normal resting pulmonary vascular resistance. Chamber function was defined by recording pressure-volume loops at steady state and during inferior vena caval occlusion during inhalation of 20 ppm nitric oxide for 10 min. We found no effect of inhaled nitric oxide on steady-state left ventricular pressures, volumes, contractility (end-systolic elastance or preload recruitable stroke work), contraction duration, or active (tau, dP/dt(min)) or passive (end-diastolic pressure-volume relation) diastolic function. Right heart filling pressures did not change. We therefore conclude that 20 ppm inhaled nitric oxide does not affect left ventricular chamber function in patients with controlled heart failure. Previously described elevations in PCWP during inhaled nitric oxide are most likely due to altered left ventricular loading conditions related to secondary pulmonary hypertension in severe heart failure.

Administration, Inhalation↗

Trends in undiagnosed HIV-1 infection among attenders at genitourinary medicine clinics, England, Wales, and Northern Ireland: 1990-6.

OBJECTIVE: To describe trends in seroprevalence of undiagnosed HIV-1 infection among attenders at 15 genitourinary medicine clinics in England, Wales, and Northern Ireland between 1990 and 1996. METHOD: Prospective, cross sectional sentinel serosurvey. Unlinked anonymous testing of remnant serum drawn for routine syphilis screening. RESULTS: In 1996, the seroprevalence of undiagnosed HIV-1 infection was 5% in homosexual men, 0.48% in heterosexual men, and 0.33% in heterosexual women. Between 1990 and 1996, there was a significant linear decrease in the seroprevalence of undiagnosed HIV-1 infection among homosexual and bisexual men within and outside London (p < 0.0001; p = 0.0141), equivalent to yearly decreases of 7.65% and 10.73% respectively. However, seroprevalence among homosexual and bisexual men under 25 years of age did not decline either inside or outside London. Seroprevalence among heterosexual men declined outside London (p < 0.005), equivalent to an average annual decrease of 14.54%. There was a significant increase among male heterosexuals inside London (p < 0.05) equivalent to a 8.09% increase per annum. Seroprevalence over time was unchanging among female heterosexuals both inside and outside London. Seroprevalence was significantly higher among those who injected drugs than those who did not report injecting in the following groups: homosexual and bisexual males within London (p < 0.005), male heterosexuals both within and outside London (p < 0.05; p < 0.05) and female heterosexuals within London (p < 0.05). CONCLUSIONS: The study highlights a significant burden of undiagnosed HIV-1 infection more than 15 years since the HIV epidemic began. Methods of offering HIV testing need to be reassessed to extend the practice of routinely testing for HIV in GUM clinics. HIV transmission among young homosexual and bisexual men continues. The contrasting trends between homosexual and bisexual men, injecting drug users, and heterosexuals attending GUM clinics indicate these groups should be considered separately. The substantial HIV seroprevalence in each group indicates that they should be priorities for targeted HIV prevention.

Adult↗