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Biomedical subjects

A M Johnson

Publications and source records attributed to A M Johnson.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effect of a new international reference preparation for proteins in human serum (certified reference material 470) on results of the College of American Pathologists Surveys for plasma proteins.

OBJECTIVE: To examine the impact of a new international reference preparation for serum proteins on the among-manufacturer variance in the College of American Pathologists Surveys. DATA SOURCE: The results of the Surveys for the years 1993-1998, supplied by the College of American Pathologists. DATA EXTRACTION AND SYNTHESIS: Mean values for manufacturers' assays were compared for each protein in the quality control samples. Results were separated by the reported reference material from which values for calibrators had been transferred. Standard statistical parameters (means, standard deviations, and coefficients of variation) were calculated from the reported means. CONCLUSIONS: Among-manufacturer coefficients of variation have dropped significantly for most serum proteins since the introduction of the new reference material. Possible reasons for continued differences are discussed.

Albumins↗
PubMed1999

A comparison of exposure groups in the EuroSIDA study: starting highly active antiretroviral therapy (HAART), response to HAART, and survival.

BACKGROUND: Concerns have been raised that intravenous drug users may be less likely to start highly active antiretroviral therapy (HAART) and that adherence to therapy may be poor among this group of patients. Given the decreased mortality and incidence of AIDS-defining illnesses among patients with HIV who start HAART, this may lead to a poorer prognosis among intravenous drug users. PURPOSE: To compare homosexual men, intravenous drug users, and heterosexuals in EuroSIDA, a prospective European cohort of 7331 patients with HIV in terms of starting a HAART treatment regimen, immunologic and virologic response to therapy, and survival. METHODS: 6645 patients were included in this analysis. Logistic regression and Cox proportional hazards models were used to investigate the factors associated with use of HAART regimens and survival following recruitment to the EuroSIDA study. RESULTS: In a multivariate logistic regression model, intravenous drug users were significantly less likely to be receiving HAART at recruitment to EuroSIDA (odds ratio [OR], 0.48; 95% confidence interval [CI], 0.37-0.62; p<.0001) when compared with homosexual men. Similarly, during follow-up, intravenous drug users were at a 27% reduced risk of starting HAART, after adjustment for other factors related to starting HAART (relative hazard [RH], 0.73; 95% CI, 0.64-0.82; p<.0001). There were no differences between heterosexual and homosexual patients, and similar results were found within regions of Europe (South, Central and Northern). Among those patients who started HAART, there were no significant differences between exposure groups in CD4 lymphocyte count response to HAART or virologic response to HAART. After adjustment for factors related to survival, intravenous drug users were at a small, but nonsignificant increased risk of death compared with homosexuals (RH 1.16; 95% CI, 0.99-1.38; p = .074). CONCLUSIONS: Intravenous drug users were significantly less likely to start HAART, but among those who did, response to therapy was similar to that of other exposure groups. There were no differences in risk of death. If intravenous drug users continue to use HAART less commonly than other exposure groups, it may result in a poorer prognosis, a different spectrum of AIDS-defining illnesses, and differential long-term clinical needs.

Adult↗
PubMed1999

The practical significance of potential biases in estimates of the AIDS incubation period distribution in the UK register of HIV seroconverters.

OBJECTIVES: To assess the practical significance of the following sources of bias for estimates of the AIDS incubation period in a large seroconverter cohort: estimation of the time of seroconversion; presentation with an HIV-related illness; preferential inclusion of survivors; loss to follow-up and analysis cut-off date; the inclusion of Kaposi's sarcoma as an AIDS event; death without an AIDS diagnosis; and representativeness of the HIV population. METHODS: Standard non-parametric survival methods were used to estimate the AIDS incubation period distribution. The practical importance of each type of bias was assessed using various sensitivity analyses. RESULTS: The potential sources of bias of most practical importance in this study were the right-censoring strategy and that due to lack of documentation of a negative HIV antibody test. Five different right-censoring strategies gave estimates of the median time to AIDS ranging from 8.1 to 10.8 years for the 1202 individuals enrolled in the UK Register of HIV Seroconverters. HIV-infected persons with a history of a previous antibody negative test which could not be verified appeared to progress to AIDS more rapidly than persons with such verification (Relative risk = 1.8, 95% confidence intervals = 1.3-2.3). CONCLUSIONS: As a number of possible causes of bias can impact on results, care must be taken to document them and control for them wherever possible. In our study, this was particularly relevant in relation to the documentation of a previous HIV antibody negative test and the choice of analysis cut-off dates. As methods may differ between cohorts, comparison of the published results from one cohort with those of another may be misleading.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Genetic investigation of novel hantaviruses causing fatal HPS in Brazil.

Although hantavirus pulmonary syndrome (HPS) was discovered in North America in 1993, more recent investigations have shown that the disease is a much larger problem in South America, where a greater number of cases and HPS-associated viruses have now been detected. Here we describe the genetic investigation of three fatal HPS cases from Brazil, including a 1995 case in Castelo dos Sonhos (CAS) in the state of Mato Grosso and two 1996 cases in the counties of Araraquara (ARA) and Franca (FRA), in the state of São Paulo. Reverse transcription-polymerase chain reaction (RT-PCR) products representing fragments of the hantavirus N, G1, and G2 coding regions were amplified from patient acute-phase serum samples, and the nucleotide (nt) sequences (394, 259, and 139 nt, respectively) revealed high deduced amino acid sequence identity between ARA and FRA viruses (99.2%, 96.5%, and 100%, respectively). However, amino acid differences of up to 14.0% were observed when ARA and FRA virus sequences were compared with those of the geographically more distant CAS virus. Analysis of a 643-nt N coding region and a 1734-nt predominantly G2-encoding region of ARA and CAS virus genomes confirmed that these Brazilian viruses were distinct and monophyletic with previously characterized Argentinean hantaviruses, and suggested that Laguna Negra (LN) virus from Paraguay was ancestral to both the Brazilian and Argentinean viruses. The phylogenetic tree based on the N coding fragment also placed LN in a separate clade with Rio Mamore virus from Bolivia. At the amino acid level, ARA and CAS viruses appeared more closely related to the Argentinean viruses than they were to each other. Similarly, analysis of the diagnostic 139-nt G2 fragment showed that the Juquitiba virus detected in a 1993 fatal HPS case close to São Paulo city, Brazil was closer to Argentinean viruses than to ARA or CAS viruses. These data indicate that at least three different hantavirus genetic lineages are associated with Brazilian HPS cases.

Antibodies, Viral↗
PubMed1999

Port-access coronary artery bypass grafting: technique and comparative results.

BACKGROUND: Interest in minimally invasive coronary artery bypass grafting (CABG) continues to grow, and the techniques evolve. Our study examines the technical strategies of port-access (PA) CABG and compares results between PA CABG and conventional CABG. METHODS: Two hundred and twenty-nine consecutive patients underwent PA CABG from December 1996 through July 1998. Postoperative complications were compared with a matched cohort of conventional access patients. Operative technique and times were reviewed in the PA group. RESULTS: The average Society of Thoracic Surgeons (STS) risk assessment was 1.3 in both groups. Observed mortality was 0.9%. Complications of stroke, perioperative myocardial infarction, and atrial fibrillation were not significantly different between the two groups. Reoperation for bleeding was more likely in the PA group, while infections were more likely in the sternotomy group (p < 0.05). Transfusion requirements and postoperative length of stay were lower in the PA group (p < 0.05). CONCLUSIONS: Early results were similar between these two low-risk cohort groups. These findings support continued careful use of port-access revascularization in low-risk patients. Close follow-up of outcomes is essential to define the appropriateness of port-access techniques in patients requiring surgical revascularization.

Aged↗
PubMed1999

Phylogenetic relationships of the genus Frenkelia: a review of its history and new knowledge gained from comparison of large subunit ribosomal ribonucleic acid gene sequences.

The different genera currently classified into the family Sarcocystidae include parasites which are of significant medical, veterinary and economic importance. The genus Sarcocystis is the largest within the family Sarcocystidae and consists of species which infect a broad range of animals including mammals, birds and reptiles. Frenkelia, another genus within this family, consists of parasites that use rodents as intermediate hosts and birds of prey as definitive hosts. Both genera follow an almost identical pattern of life cycle, and their life cycle stages are morphologically very similar. However, the relationship between the two genera remains unresolved because previous analyses of phenotypic characters and of small subunit ribosomal ribonucleic acid gene sequences have questioned the validity of the genus Frenkelia or the monophyly of the genus Sarcocystis if Frenkelia was recognised as a valid genus. We therefore subjected the large subunit ribosomal ribonucleic acid gene sequences of representative taxa in these genera to phylogenetic analyses to ascertain a definitive relationship between the two genera. The full length large subunit ribosomal ribonucleic acid gene sequences obtained were aligned using Clustal W and Dedicated Comparative Sequence Editor secondary structure alignments. The Dedicated Comparative Sequence Editor alignment was then split into two data sets, one including helical regions, and one including non-helical regions, in order to determine the more informative sites. Subsequently, all four alignment data sets were subjected to different tree-building algorithms. All of the analyses produced trees supporting the paraphyly of the genus Sarcocystis if Frenkelia was recognised as a valid genus and, thus, call for a revision of the current definition of these genera. However, an alternative, more parsimonious and more appropriate solution to the Sarcocystis/Frenkelia controversy is to synonymise the genus Frenkelia with the genus Sarcocystis.

Animals↗
PubMed1999

Physical characterisation of the plastid DNA in Neospora caninum.

The physical characteristics of the plastid DNA in Neospora caninum were investigated using pulsed-field gel electrophoresis and TEM. In a comparison of contour-clamped homogenous electric field and field inversion gel electrophoresis, the latter proved the more successful technique for studying the plastid molecules. In most cases, restriction or modifying enzymes were required to enable the plastid DNA molecules to enter the gel from the well area. The unit length of the plastid of N. caninum is approximately 35 kb; however, there is evidence for the formation of oligomeric molecules, which may migrate as linear molecules in approximate multiples of the unit length. Four different plastid genes encoding the ssrRNA, lsrRNA, rpoC and tufA genes were identified by hybridisation studies of contour-clamped homogenous electric field and field inversion gel electrophoresis gels. Transmission EM was performed on isolated plastid DNA, and circular structures similar in size and appearance to those described in other apicomplexans were observed, with an approximate length of 19 microm. The data presented here conclusively show that the Nc-Liverpool canine strain of N. caninum possesses a plastid DNA, with physical characteristics similar to the plastids found in other apicomplexans.

Animals↗
PubMed1999

Differential recognition of Toxoplasma gondii recombinant nucleoside triphosphate hydrolase isoforms by naturally infected human sera.

Toxoplasma gondii possesses a highly active nucleoside triphosphate hydrolase, which has been shown to be an immunodominant antigen in mice and humans. Two isoforms (I and II) which exhibit different activities with respect to hydrolysis of ATP exist. Past studies suggest that all strains of T. gondii contain the less active nucleoside triphosphate hydrolase II, whilst only virulent strains contain the nucleoside triphosphate hydrolase I isoform. In order to further investigate the correlation between nucleoside triphosphate hydrolase isoform and biological significance, we cloned and expressed as glutathione S-transferase fusion proteins the full-length nucleoside triphosphate hydrolase I and II isoforms and two truncations of the nucleoside triphosphate hydrolase I isoform in Escherichia coli. We then used ELISAs with the full-length recombinant nucleoside triphosphate hydrolases as antigens to examine 188 naturally infected T. gondii-positive sera and 83 T. gondii-negative sera for antibody reactivity. All positive sera reacted to T. gondii whole tachyzoite lysate antigen, 31 sera reacted to both nucleoside triphosphate hydrolase isoforms, three sera reacted specifically to nucleoside triphosphate hydrolase I and two sera reacted to only nucleoside triphosphate hydrolase II. Immunoblot analysis of the five sera reacting to either nucleoside triphosphate hydrolase I or II revealed both quantitative and qualitative differences in reactivity to the two isoforms. Comparative immunoblot analysis using the truncations of the nucleoside triphosphate hydrolase I isoform, and one of these positive sera identified a presumptive differential epitope between the nucleoside triphosphate hydrolase I and II isoforms within an 81 amino acid region (amino acids 445-526) at the C-terminus of the nucleoside triphosphate hydrolase I isoform. This differential reactivity was further localised to the 12-residue region of greatest variability between the two isoforms (residues 488-499) using synthetic peptides. This is the first report where naturally infected human sera have been used to identify a differential epitope. Because this region is essential for substrate binding, an antibody response to this region may play some role in inhibition of this highly active enzyme.

Acid Anhydride Hydrolases↗
PubMed1999

Phylogenetic analysis based on full-length large subunit ribosomal RNA gene sequence comparison reveals that Neospora caninum is more closely related to Hammondia heydorni than to Toxoplasma gondii.

Since its first description in the late 1980s, Neospora caninum has been recognised as a prominent tissue cyst-forming parasite due to its ability to induce congenital disease and abortion in animals, especially cattle. It is found worldwide and is a cause of significant economic losses for the livestock industry. However, its place within the family Sarcocystidae, like that of several other taxa, remains unresolved. Neospora caninum shares several morphological and life cycle characters with Hammondia heydorni, although it is most commonly thought of as being a close relative of Toxoplasma gondii. This study presents information regarding the phylogenetic relationship of N. caninum to species currently classified into the genus Hammondia, as well as to two strains (RH and ME49) of T. gondii based on the full-length large subunit ribosomal RNA gene. Phylogenetic analyses using two alignment strategies and three different tree-building methods showed that the two species in the genus Hammondia are paraphyletic. Neospora caninum was shown to form a monophyletic clade with H. heydorni instead of T. gondii, which in turn was shown to be most closely related to H. hammondi. The finding that N. caninum and H. heydorni are closely related phylogenetically may aid the elucidation of currently unknown aspects of their biology and epidemiology, and suggests that H. heydorni should be considered in the differential diagnosis of N. caninum from other apicomplexan parasites.

Animals↗
PubMed1999

Cytokines, nitric oxide, heat shock proteins and virulence in Toxoplasma.

Elucidating the factors that play important roles in the expression of virulence by parasites is crucial to understanding disease pathogenesis and to developing control strategies rationally. Here, Kate Miller, Nick Smith and Alan Johnson, using Toxoplasma gondii as a model, argue that the interactions between the immune system and 70 kDa heat shock proteins of apicomplexan parasites profoundly influence parasite virulence.

Animals↗
PubMed1999

Evaluation of colonic diverticular disease in autosomal dominant polycystic kidney disease without end-stage renal disease.

A previous study had shown an increased prevalence (83%) of diverticula among patients with autosomal dominant polycystic kidney disease (ADPKD) with end-stage renal disease (ESRD) compared with other ESRD patients without ADPKD (32%). Others have also suggested an increased risk for diverticular complications in renal transplant recipients with ADPKD. To determine whether there was an increased occurrence of diverticula among non-ESRD patients with ADPKD, we studied 55 patients with ADPKD who were not receiving renal replacement therapy compared with 12 unaffected family members (non-ADPKD) and 59 random patients who had undergone barium enemas (control [C]). No study patient had a history of diverticular disease. All patients underwent a double-contrast barium enema after administration of glucagon. The occurrence, number, location, and size of diverticula were noted. There was no significant difference among the three groups in regard to sex (men: ADPKD, 42% versus non-ADPKD, 42% versus C, 37%) or age (ADPKD, 49.3 +/- 0.7 versus non-ADPKD, 51.2 +/- 2.1 versus C, 49 +/- 1 years). There was no significant difference in the percentage of patients with diverticula (ADPKD, 47% versus non-ADPKD, 58% versus C, 59%), the percentage with only right-colon diverticula (ADPKD, 5% versus non-ADPKD, 17% versus C, 5%), the mean number of diverticula in patients with diverticulosis (ADPKD, 13.8 versus non-ADPKD, 7.9 versus C, 9.9 diverticula), or the size of the largest diverticula (ADPKD, 9.5 versus non-ADPKD, 10.4 versus C, 10.5 mm). There was no significant difference in these variables between the patients with ADPKD with a creatinine clearance greater than 70 mL/min/1.73 m(2) (n = 25) or less than 70 mL/min/1.73 m(2). This study does not show the greater prevalence of diverticular disease in non-ESRD patients with ADPKD compared with the general population. Thus, patients with ADPKD need not be considered at greater risk for diverticular disease than the general population.

Diverticulum, Colon↗
PubMed1999

Frequency of ovarian cysts in patients with autosomal dominant polycystic kidney disease.

Extrarenal cysts occur in patients with autosomal dominant polycystic kidney disease (ADPKD) most frequently in the liver. Ovarian cysts have been reported in women with ADPKD, but their frequency has not been determined. Therefore, we analyzed the historical data in our database of 337 women with ADPKD and 199 of their unaffected female family members (NADPKD). In addition, we prospectively studied 25 nonpregnant, premenopausal women with ADPKD and 25 nonpregnant, premenopausal, age-matched control women recruited from the general population to assess the occurrence of ovarian cysts. No women in either the control or ADPKD groups were receiving exogenous estrogen or progesterone. All women underwent sonographic examination using a 5- or 7.5-MHz vaginal probe. A normal ovarian follicle was defined as a fluid-filled structure less than 2 cm in average diameter, and an ovarian cyst as one of 2 cm or greater. From the historical data, 28% of the women with ADPKD gave a history of ovarian cysts compared with 18% of the NADPKD women (P < 0.05). In the prospective study, the mean age of the women with ADPKD was not different from that of the control women (40.9 +/- 1.2 v 39.3 +/- 1.2 years; P = not significant [NS]). There was no difference in frequency of normal follicles found in women with ADPKD or controls (80% v 96%; P = NS), nor was there a difference in the frequency of ovarian cysts found in women with ADPKD or controls (12% v 12%; P = NS). There was no difference in the calculated ovarian volumes between the women with ADPKD and controls (9.9 +/- 2. 5 v 7.2 +/- 1.2 cm3). Among the women with ADPKD, there was no correlation between mean ovarian volume and mean renal volume, nor was there a significant relationship between the occurrence of hepatic cystic disease and ovarian cysts. Therefore, a prospective imaging study suggests that ovarian cysts have no increased frequency in women with ADPKD compared with women in the general population.

Adult↗
PubMed1999

Renal asymmetry in children with autosomal dominant polycystic kidney disease.

Although for decades autosomal dominant polycystic kidney disease (ADPKD) was considered a disease of adults, our recent longitudinal studies on children from ADPKD families have shown that the disease is evident by ultrasound imaging in approximately 75% of children who are carriers of the ADPKD1 gene, the most common form of ADPKD. Here we report that, in contrast to adults, the disease appears to be unilateral initially in approximately 17% of children. Asymmetric enlargement of the kidneys is also frequently observed. This renal asymmetry can be extreme and lead to diagnostic confusion. We present 2 unusual cases of asymmetric renal involvement that we have observed during the last 10 years. The first is a 14-year-old boy who was scheduled for a nephrectomy to relieve pain and whose family requested a second opinion. The second is a 10-year-old girl who was diagnosed with ADPKD in utero by prenatal ultrasound. After birth, 1 kidney progressively developed cysts and enlarged, whereas the other had only a few tiny cysts and remained normal in size. A review of the literature shows that presentations like these often lead to a nephrectomy or surgical biopsy. A carefully obtained family history and examination of both parents with ultrasound can help to avoid unnecessary invasive procedures. If pain is a prominent symptom, it can be treated by cyst aspiration if there are only a few cysts or a single dominant cyst. The molecular mechanism for extremely asymmetric renal disease remains to be elucidated.

Adolescent↗
PubMed1999

Long-term follow-up of upper extremity implanted venous access devices in oncology patients.

PURPOSE: To evaluate function and assess incidence of complications relating to upper extremity implanted venous access devices placed in oncology patients primarily for chemotherapy. MATERIALS AND METHODS: The authors retrospectively evaluated the clinical course of 205 upper extremity implanted venous access devices placed with fluoroscopic and sonographic guidance in 204 patients during a 2-year period. All patients had a diagnosis of malignancy for which chemotherapy was planned. Follow-up data were collected by patient examination, direct evaluation of device function, as well as chart review and review of relevant imaging procedures. A modified technique for device placement is described. RESULTS: The devices were placed successfully on the initial attempt in all cases. Clinical follow-up was obtained for 195 devices (95.1%) for a total device service period of 33,619 days (mean service interval = 169 days). Seventy-eight devices (40%) had service intervals greater than 180 days. Thirty-seven devices (19% of total devices) led to 39 complications (0.116 event/100 days). No immediate procedural complications were incurred. Eight complications occurred after 180 days of port service. Nineteen devices (9.7% of total devices followed) required removal as a result of complication. Common complications included port malfunction requiring urokinase to clear (n = 10; 0.030 event/100 days), ipsilateral upper extremity deep venous thrombosis (n = 9; 0.027), and local infection (n = 7, 0.021). A comparison of these results relative to other published series of similar devices placed for mixed indications is presented. CONCLUSIONS: Implanted venous access devices are an effective means of long-term venous access in oncology patients. Complication rates in this large series compared favorably to other published radiologic and surgical series. Analysis of complications in a subgroup of extended use implanted venous access devices (greater than 180 days follow-up) showed no statistically significant (P < .05) difference from the larger group of devices.

Adult↗
PubMed1999

Reversal of left ventricular hypertrophy with angiotensin converting enzyme inhibition in hypertensive patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Hypertension occurs commonly and early in the natural history of autosomal dominant polycystic kidney disease (ADPKD), affecting both renal and patient outcome. Activation of the renin angiotensin aldosterone system due to cyst expansion and local renal ischaemia plays an important role in the development of ADPKD related hypertension and left ventricular hypertrophy (LVH), a known important risk factor for cardiovascular morbidity and mortality. The aim of this study was to investigate the effects of an angiotensin converting enzyme (ACE) inhibitor, enalapril, on renal function, blood pressure and LVH in hypertensive ADPKD patients. METHODS: Fourteen hypertensive ADPKD patients (11 men, 3 women; mean age: 40 years) were included in the study. All patients had LVH and creatinine clearance (Cer) greater than 50 ml/min/1.73 m2. The patients were followed for 7 years on enalapril therapy. The effects of enalapril on renal function, blood pressure and LVH were investigated. RESULTS: Baseline measurements of mean arterial pressure (MAP), Ccr and left ventricular mass index (LVMI) were 110 +/- 2 mmHg, 84 +/- 6 ml/min/1.73 m2 and 146 +/- 4 g/m2, respectively. After one year of enalapril therapy there was a significant decrease in MAP (94 +/- 3 mmHg, P < 0.005) which remained stable until the end of the study at 7 years (94 +/- 1 mmHg, P < 0.005 vs baseline). There was also a significant decrease in LVMI (131 +/- 6 g/m2, P < 0.05) after year 1 which continued to decrease until the end of the study reaching 98 +/- 6 g/m2 (P < 0.01 vs year 1 and baseline). Although Ccr remained stable after year 1, a significant decrease was observed after 7 years of follow-up (59 +/- 6 ml/min, P < 0.001 vs year 1 and baseline). CONCLUSIONS: ACE inhibition in hypertensive ADPKD patients provided long-term reversal of LVH in association with a mean 3.6 ml/min/year decline of Ccr. These preliminary results have potential important implications for cardiovascular and renal protection in ADPKD.

Adult↗
PubMed1999

Developing surveillance for HIV transmission and risk behaviours among high-risk groups in a central London health district.

BACKGROUND: Our aim was to describe surveillance data on HIV transmission and risk behaviours in Camden and Islington, an inner London health district (population 360 000). This information is required to assess the effectiveness of HIV-AIDS prevention. METHODS: We focused on two groups in the local population most severely affected by the HIV epidemic: homosexual and bisexual men, and injecting drug users. Data were drawn from routine and survey data, national and local sources, and a special local survey. RESULTS: There were estimated to be 9250 homosexual men, with an estimated prevalence of 7.7 per cent (confidence interval (CI) 5.9-11.0) diagnosed with HIV infection resident within the health district, and 9900 injecting drug users, with an estimated prevalence of 0.8 per cent (CI 0.6-1.1), diagnosed with HIV infection. New HIV infections diagnosed amongst homosexual men having a named test in HIV testing services averaged 281 and was unchanged between 1992 and 1996. However, unlinked anonymous seroprevalence surveys showed a decline in HIV prevalence for both homosexual men attending a genito-urinary medicine clinic and for injecting drug users attending services. Local surveys indicated that, in the preceeding year, one in three homosexual men had had unprotected anal intercourse with a man, and 13 per cent of intravenous drug users had shared equipment. There appeared to be no change in these levels over the years studied. CONCLUSION: Population-based information on HIV is available at local level in England. It can be used for surveillance of HIV transmission and behaviour in high-risk groups, especially homosexual and bisexual men and intravenous drug users. Resources for HIV prevention are provided to all NHS districts, and surveillance is a cost-effective measure of the outcome of HIV prevention.

Adolescent↗
PubMed1999

Risk of cancer in patients with HIV disease. London African HIV/AIDS Study Group.

The aim of this study was to compare cancer incidence in a cohort of HIV-infected patients with the incidence rates in the population of South East England. Data collected for a retrospective cohort study of 2048 HIV-infected patients were analysed to examine the incidence of cancer. Cases of cancer occurring in South East England from 1985-1995 were obtained from the Thames Cancer Registry. Standardized incidence ratios were calculated by comparison of the observed number of cases for each cancer type in HIV-infected non-Africans with the numbers expected, calculated from the age and sex specific registration rates for the South East England population using person-years of observation. The crude incidence rates of cancer were calculated for HIV-infected Africans. The incidence of non-AIDS defining cancers such as Hodgkin's disease (standardized incidence ratio 22; 95% CI: 3-80) and anal cancer (standardized incidence ratio 125; 95% CI: 3-697) were significantly increased for non-African males with HIV disease. Anal cancer was also significantly increased for non-African females (standardized incidence ratio 1667; 95% CI: 43-9287). Kaposi's sarcoma (KS) was the commonest cancer among HIV-infected Africans and males had an incidence which was nearly 3 times that of females. There is evidence to suggest that the risks for other non-AIDS defining cancers were significantly increased in persons with HIV disease which may have implications for HIV/AIDS surveillance.

Adult↗