Biomedical subjects
Publications and source records attributed to J M Parkin.
A study of HIV post-exposure prophylaxis in 28 recipients showed that indinavir-containing regimens were poorly tolerated. This finding has implications for compliance and efficacy of the currently recommended combinations.
The objective of the study was to investigate the safety and antiviral effect of three delavirdine dose regimens or placebo in combination with zidovudine in patients who were already taking zidovudine. Eighty-nine symptomatic HIV-1 seropositive individuals with CD4 cell counts between 50 and 350 cells/microl were included in this trial The influence of combination therapy on viral susceptibility to both zidovudine and delavirdine was investigated. Death or the occurrence, or re-occurrence of an AIDS-defining illness was considered as a clinical endpoint. The addition of delavirdine to the antiretroviral treatment regimen resulted in a significant, but transient, reduction in virus load, as determined by quantitative RNA measurements. CD4+ cell count did not change significantly. Susceptibility to zidovudine remained unchanged after 12 weeks of combination therapy, while 70% of the patients demonstrated a substantial decrease (> 10-fold) in sensitivity to delavirdine. Two patients suffered from an AIDS-defining disease during the study. No deaths occurred. Generally, the drug appeared to be safe. Skin rash was the most frequently observed adverse event (52%). In most patients the rash either resolved spontaneously or was treated successfully with a short course of antihistamines. The definite place of the compound in the management of HIV disease, in particular when given in combination with other antiretroviral agents, remains to be further explored.
To examine the effect of ambient temperature on metabolism during fatiguing submaximal exercise, eight men cycled to exhaustion at a workload requiring 70% peak pulmonary oxygen uptake on three separate occasions, at least 1 wk apart. These trials were conducted in ambient temperatures of 3 degrees C (CT), 20 degrees C (NT), and 40 degrees C (HT). Although no differences in muscle or rectal temperature were observed before exercise, both muscle and rectal temperature were higher (P < 0.05) at fatigue in HT compared with CT and NT. Exercise time was longer in CT compared with NT, which, in turn, was longer compared with HT (85 +/- 8 vs. 60 +/- 11 vs. 30 +/- 3 min, respectively; P < 0.05). Plasma epinephrine concentration was not different at rest or at the point of fatigue when the three trials were compared, but concentrations of this hormone were higher (P < 0.05) when HT was compared with NT, which in turn was higher (P < 0.05) compared with CT after 20 min of exercise. Muscle glycogen concentration was not different at rest when the three trials were compared but was higher at fatigue in HT compared with NT and CT, which were not different (299 +/- 33 vs. 153 +/- 27 and 116 +/- 28 mmol/kg dry wt, respectively; P < 0.01). Intramuscular lactate concentration was not different at rest when the three trials were compared but was higher (P < 0.05) at fatigue in HT compared with CT. No differences in the concentration of the total intramuscular adenine nucleotide pool (ATP + ADP + AMP), phosphocreatine, or creatine were observed before or after exercise when the trials were compared. Although intramuscular IMP concentrations were not statistically different before or after exercise when the three trials were compared, there was an exercise-induced increase (P < 0.01) in IMP. These results demonstrate that fatigue during prolonged exercise in hot conditions is not related to carbohydrate availability. Furthermore, the increased endurance in CT compared with NT is probably due to a reduced glycogenolytic rate.
OBJECTIVES: To analyse use of antiretroviral therapy within Europe between 1994 and 1997. DESIGN: From September 1994, the EuroSIDA study (cohorts I-III) has prospectively followed unselected HIV-infected patients from 50 clinical centres in 17 European countries (total, 7230). METHODS: Patients under follow-up at half-year intervals from September 1994 (n=2871) to September 1997 (n=3682) were classified according to number of drugs currently used (none, one, two, three, four or more). Use of antiretroviral therapy was stratified by CD4 cell count (< 200 versus > or = 200 x 10(6)/l) and by region of Europe (south, central, or north). Frequency data were compared by chi2 test and logistic regression modelling. RESULTS: The proportion of patients on antiretroviral monotherapy diminished over time (1994, 42%; 1997, 3%), as did the proportion of patients without therapy (from 37 to 9%). Over time, the proportion of patients on triple (from 2 to 55%) and quadruple (from 0 to 9%) therapy increased, whereas use of dual therapy peaked in 1996 and subsequently fell. In the three regions of Europe, changes in use of antiretroviral therapy differed substantially. However, as of September 1997, only minor differences persisted. The proportion of patients on dual, triple, and quadruple therapy were as follow: south, 33, 52 and 5%, respectively; central, 23, 55 and 14%, respectively; north, 16, 59 and 10%, respectively. In September 1997, odds for use of three or more drugs including at least one protease inhibitor did not differ significantly between regions. CONCLUSIONS: Use of antiretroviral therapy in Europe has changed dramatically towards combination treatment in the last few years. Regional differences in use of antiretroviral therapy have decreased, and by September 1997 only minor differences remained. Antiretroviral therapy with three or more drugs and use of protease inhibitors has become more common in all regions of Europe.
A review of imaging in the acquired immune deficiency syndrome (AIDS) is presented. The imaging features can be conveniently categorized according to whether the presenting complications are infective (bacterial, protozoal, or fungal), bronchiectasis, neoplastic (Kaposi's sarcoma, AIDS-related lymphoma, or lymphoproliferative disease), or a miscellaneous group (non-specific interstitial pneumonitis, persistent generalized lymphadenopathy, or bronchogenic carcinoma).
The objective of this study was to assess the role of anti-retroviral therapy (ART) on the susceptibility of peripheral blood lymphocytes (PBL) from HIV-1-infected individuals to activation-induced apoptosis and in comparison with changes in CD4 lymphocyte counts. Eleven symptomatic HIV+ patients were studied. Ex vivo apoptosis was measured in phytohaemagglutinin (PHA)-stimulated PBL and CD4 subsets by flow cytometry, at baseline and after 1 month (4-6 weeks) and 2/3 months of ART. Six patients had extended studies of the effects of therapy to a maximum of 21 months. Lymphocyte apoptosis was significantly elevated in HIV+ patients at baseline (median 22% compared with 7.5% in HIV- risk-matched controls; P < 0.05). This decreased to control levels on ART (7.4% at 4-6 weeks, P < 0.01, and 6.2% at 8-12 weeks, P < 0.05, compared with baseline). Similar changes occurred in the CD4+ subpopulation. The decrease in apoptosis was maintained for several months, but the effect was rapidly lost if ART was discontinued. CD4 counts showed a reciprocal relationship to changes in apoptosis. The association of changes in apoptosis with those in CD4 counts suggests a link between programmed cell death and lymphocyte depletion. Apoptosis reduced in some individuals without any reduction in viral load, suggesting apoptosis may be influenced by factors in addition to the overall extent of HIV replication.
Peripheral blood mononuclear cells were prepared from human immunodeficiency virus-positive (HIV+) individuals (n = 46) to investigate the expression of both chains of the interleukin-2 receptor. Both qualitative and quantitative changes in expression were observed. Total lymphocyte expression of the IL-2 alpha chain (CD25) was decreased compared with HIV-negative (HIV-) controls. This was due to the decrease in the CD4+ population, which favored expression of this receptor, rather than a decrease in expression, per se. CD8+ lymphocytes expressed the beta chain (CD122) in the absence of the alpha chain. However, a significant increase in the number of peripheral blood CD8+ lymphocytes expressing mainly the beta subunit was observed in HIV+ patients (P = 0.02). This was observed to a similar extent in asymptomatic and symptomatic patients and characterized a subpopulation of T lymphocytes expressing high levels of CD8. Lymphocytes from patients with advanced HIV disease failed to up-regulate both alpha and beta chains in response to mitogenic concentrations of phytohaemagglutanin. However, those cells that were able to up-regulate both of the IL-2 receptors were capable of effective signal transduction through the receptor, increasing the proliferative response to stimulation.
We have investigated the effect of the anticancer compound, camptothecin on Jurkat T-cells, a lymphoblastoid leukemic cell-line. Exposure to low concentrations led to rapid cessation of DNA (more than 95%) and RNA (more than 75%) synthesis. Perturbations to the cell cycle were observed following exposure which caused a significant accumulation of cells within G1 (P = 0.03) with a concomitant decrease in G2/M (P = 0.025). Concentrations below 0.1 microM could inhibit DNA synthesis but not induce apoptosis. Induction of apoptosis was dose dependent and could be detected as early as 3 h post exposure. The apoptotic population appeared to be derived from G1 and S-phase cells but not G2/M, coinciding with the cell cycle compartments in which DNA and RNA polymerases function. However, direct inhibition of DNA polymerase alone was not shown to be associated the induction of apoptosis or with a decrease in susceptibility to camptothecin-induced cell death. The effects of camptothecin on Jurkat T-cells and the potential mechanisms involved are discussed in the context of observations made in other transformed cell lines.
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AIM: To correlate the appearances of high resolution computed tomography (HRCT) with the bronchoalveolar lavage (BAL) findings in HIV positive patients in whom there is a strong clinical suspicion of Pneumocystis carinii pneumonia (PCP) but a normal chest radiograph. PATIENTS AND METHODS: The 13 patients available for analysis fulfilled the following criteria: HIV positive, CD4 count less than 200 cells per mm3, non-productive cough or non-purulent sputum daily, documented fever above 37.5 degrees C for more than a week, dyspnoea or decreased exercise tolerance and normal chest X-ray. HRCT of the lungs was performed within 24 h of the chest radiograph, using 1 mm slice at 2 cm intervals, reconstructed using a high resolution algorithm. Bronchoalveolar lavage samples were taken for cytological examination, microscopy, culture and sensitivity. The HCRT findings were correlated with the results of BAL and clinical outcome. RESULTS: Of the 13 patients studied, four had patchy ground-glass opacities and one also had interstitial thickening. All four proved to have PCP on BAL. None of the nine patients who were negative for PCP on BAL had ground-glass opacity or abnormalities attributable to PCP. CONCLUSION: In this study HRCT showed abnormalities consistent with PCP in all four patients who had PCP on BAL before there were chest radiograph abnormalities. The use of HRCT may help avoid unnecessary delay, allow early medical intervention and, if our results are confirmed by larger series, may reduce the need for bronchoscopy.
OBJECTIVES: To investigate, in lymphocytes from HIV-1-infected individuals, the phenotypic expression of various adhesion co- or counter-receptors [lymphocyte function-associated antigen (LFA)-3, LFA-1 and intercellular adhesion molecule (ICAM)-1] involved in providing the co-stimulatory signal through the phospholipase C-gamma pathway in relation to inositol polyphosphate metabolism. DESIGN AND METHODS: Cell adhesion molecule profiles of peripheral blood lymphocytes (PBL) from 39 HIV-1-infected individuals at various stages of infection and 20 healthy laboratory controls were studied using flow cytometry. These were studied in 14 patients with late-stage disease in conjunction with their inositol polyphosphate metabolic profiles measured by high performance liquid chromatography. Levels of HIV-1 present in cell lysates were concurrently measured by a p24 antigen capture assay. In addition, the effects of a specific anti-ICAM-1 antisense oligonucleotide on the intracellular phosphatase activities of lymphocytes from a separate group of eight HIV-1-infected individuals were examined. RESULTS: The expression of LFA-1, a beta 2 integrin, was upregulated among patient PBL in parallel with disease progression, whereas that of LFA-3 (CD58) was found to be significantly reduced among the CD4+ lymphocyte subset in all stages of infection. The 5-phosphatase activity, which we previously observed to be defective in HIV disease, was found to correlate linearly with the expression of both LFA-1 and its ligand, ICAM-1. Treatment of patient lymphocytes with an antisense oligonucleotide, which reduced the cell surface expression of ICAM-1 by blocking the translation of its mRNA, resulted in further reduction of intracellular phosphatase activities. CONCLUSIONS: Our results suggest a pivotal role for adhesion co- and counter-receptors in influencing lymphocyte signalling and hence cellular response to recall antigens in HIV-1-infected individuals.
The prevalence of dyslipidaemia in children with insulin dependent diabetes mellitus (IDDM) and its relation to glycaemic control was studied in a group of 51 diabetic children and a control population of 132 schoolchildren. The prevalence of dyslipidaemia in the fasting state was increased in the diabetic group (39%) compared with control subjects (17%). Serum cholesterol concentration alone was raised in 25% of diabetic subjects while serum cholesterol and triglycerides were raised in 14%, compared with 16% and 0.7% respectively in control subjects. Serum total cholesterol (5.1 v 4.5 mmol/l), low density lipoprotein cholesterol (3.2 v 2.6 mmol/l), non-esterified fatty acids (0.91 v 0.50 mmol/l), and triglycerides (0.94 v 0.76 mmol/l) were higher in diabetic children. Serum total cholesterol, triglycerides, and apolipoprotein (apo)B concentrations increased with worsening control, while serum high density lipoprotein cholesterol and apoA-I concentrations were unaltered. There were also positive correlations between glycated haemoglobin and total cholesterol, triglycerides, and apoB in diabetic children. Thus, abnormalities in circulating lipids are common in young subjects with IDDM but largely disappear if blood glucose concentrations are reasonably controlled.
Serum total cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, apolipoprotein (apo) A-I and apoB concentrations were estimated and low-density lipoprotein (LDL) cholesterol levels were calculated in 132 children aged 11.4-17.3 years. The effect of feeding was investigated by estimating postprandial values and also by studying the effects of a test meal. The distribution of all data was consistent with Gaussian apart from triglycerides which was log normal. Overall fasting values were [mean (standard deviation; SD)] cholesterol 4.5 (0.8) mmol/L, HDL cholesterol 1.5 (0.4) mmol/L, LDL cholesterol 2.6 (0.8) mmol/L, apoA-I 1.5 (0.3) g/L, apoB 1.0 (0.4) g/L and triglycerides 0.76 (0.38-1.51) mmol/L, the values for triglycerides being mean (95% confidence intervals). Girls had higher triglycerides than boys [0.82 (0.43-1.54) versus 0.70 (0.36-1.33)] and different effects of age on lipids were found, HDL cholesterol being negatively correlated with age in boys (r = -0.37; P < 0.001), but not in girls, and apoA-I being negatively correlated with age in boys (r = -0.31; P = 0.006), but positively correlated with age in girls (r = 0.32; P = 0.008). Triglycerides rose and HDL cholesterol fell following feeding and inconsistent effects were seen on apoA-I and apoB.
AIMS: To differentiate between reinfection and relapsing infection with Staphylococcus epidermidis in a middle-aged woman with defective opsonisation and procidin function in serum. METHODS: Microbiological typing was done by biotyping, phage typing, and polyacrylamide gel electrophoresis of radiolabelled bacterial proteins (radioPAGE method). Polymorphonuclear cell function was assessed in vitro by phagocytosis and killing of Candida albicans; measurement of neutrophil random locomotion and chemotaxis; reduction of nitroblue tetrazolium after stimulation by opsonised Candida and a radiometric saccharomyces opsonisation assay. The effect of plasma infusions on opsonic activity was assessed by chemiluminescence using control polymorphonuclear leucocytes with a laboratory strain of S epidermidis opsonised with either patient or control serum. RESULTS: Recurrent reinfection with different strains of Staphylococcus epidermidis rather than relapsing infection was confirmed as having occurred by typing bacterial strains. The RadioPAGE method detected all the S epidermidis strains involved in this patient's illness. The patient's serum was shown to be defective in both opsonin and procidin function. The defects were correctable in vitro by the addition of normal serum. Clinical recovery occurred after repeated infusions of normal fresh frozen plasma and prolonged antibacterial treatment; antibacterial treatment alone was insufficient. CONCLUSIONS: The radioPAGE method is useful in distinguishing recurrent reinfection with S epidermidis from relapsing infection with this organism. Elucidation of the nature of, and underlying predisposition to, infection in the patient studied allowed a rational treatment plan of plasma infusion combined with antibacterial treatment to be devised which ultimately proved successful.
OBJECTIVE: To determine the incidence of insulin dependent diabetes in the Northern region of England in children less than 16 years old in the period 1977 to 1986 and to relate the incidence data to an index of deprivation. DESIGN: Retrospective analysis of hospital case records identified from the regional health authority's computer; validation of the primary source with hospital clinic registers and community paediatric registers. SETTING: Northern region, excluding South Cumbria District Health Authority (659,300 children under 16 in 1981). PATIENTS: All children diagnosed with insulin dependent diabetes before the age of 16 and resident in the region at time of diagnosis. MAIN OUTCOME MEASURES: Incidence rates for the 10 year period and analysis of incidence rates within categories of deprivation. RESULTS: 919 incident cases were identified. The validation procedure covered 54% of all cases identified and gave 95% completeness of ascertainment. The average annual incidence over the 10 year period was 14.8/100,000 for girls and 13.4/100,000 for boys. The annual incidence for the most and least deprived areas of the region was 18.7/100,000 (95% confidence interval 16.2 to 21.5) for boys and 7/100,000 (5.6 to 8.8) for girls. There was a highly significant trend (p less than 0.001) of decreasing incidence with decreasing level of deprivation. CONCLUSIONS: In the north of England the incidence of childhood diabetes is related to material deprivation.
A 7-year-old boy with a systematized verrucous epidermal naevus, multiple pigmented naevocytic naevi and precocious puberty is described. The possible basis for this previously unreported association of abnormalities is discussed.
Polymorphonuclear cell function tests were performed in 340 patients with recurrent unexplained infections. Serum-dependent defects in phagocytosis and intracellular killing of Candida albicans (Candida opsonin and procidin defects) were specifically associated with susceptibility to recurrent pyogenic infections, Candida opsonin defects occurring in 12.7% and Candida procidin defects in 20.8% of patients compared with 3.7% of healthy controls. Saccharomyces cerevisiae opsonin deficiencies were also found frequently in patients with recurrent infections, being present in 18.2% compared with 7.4% controls, although not specifically in those with pyogenic infection.
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