The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-c30): validation of English version in Singapore

OBJECTIVE

This study aimed to validate the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30, English version 3.0) in Singaporean cancer patients.

METHODS

In a cross-sectional study, a heterogeneous sample of cancer patients (n = 57) self-administered a questionnaire containing the QLQ-C30, the Short Form 36 Health Survey (SF-36) and assessing health and sociodemographic status. Construct validity was assessed by testing a priori hypotheses that QLQ-C30 scales would be moderately or strongly correlated with SF-36 scales measuring similar dimensions of health-related quality of life (HRQoL) and that subjects reporting mild symptoms would have better HRQoL scores than those reporting severe symptoms. Internal consistency reliability was assessed using Cronbach's alpha.

RESULTS

Strength of Spearman's correlations between the QLQ-C30 and SF-36 scales assessing similar dimensions of HRQoL ranged from 0.35 to 0.67. Subjects with mild symptoms had better scores than those with severe symptoms for all six QLQ-C30 HRQoL scales (p < 0.05 for five scales, Mann-Whitney U tests). Cronbach's alpha ranged from 0.19 for the cognitive functioning scale to 0.91 for the global QoL scale.

CONCLUSION

This study provides preliminary evidence for the validity and reliability of the EORTC QLQ-C30 in English-speaking Singaporean cancer patients.

Validity and reliability of the Chinese (Singapore) version of the Parkinson’s Disease Questionnaire (PDQ-39)

OBJECTIVE

The purpose of the study was to validate the Chinese (Singapore) version of the Parkinson's Disease Questionnaire (PDQ-39CSV) and its briefer version (PDQ-8CSV).

METHODS

A convenience sample of Chinese-speaking Singaporeans with Parkinson's disease (PD) (n = 63) completed a questionnaire containing the PDQ-39CSV and the Chinese (Singapore) EQ-5D. A subgroup also participated in a retest and/or a focus group discussion. A priori hypotheses were tested by examining correlations between PDQ-39CSV, PDQ-8CSV and EQ-5D scores and using principal component factor analysis. Reliability was assessed using Cronbach's alpha and intra-class correlation coefficients (ICC).

RESULTS

Thirty-two PDQ-39CSV items correlated satisfactorily with their hypothesized dimensions (Spearman's p > or = 0.4). Factor analysis yielded a component on which all 8 PDQ-39CSV dimensions were substantially loaded (loading range: 0.53-0.89). As hypothesized, the PDQ-39CSV and PDQ-8CSV summary indices were highly correlated (Pearson's r:0.95, ICC:0.94); correlations between related PDQ and EQ-5D scores were generally strong (Spearman's p: 0.38-0.76, p < 0.001 for all). Cronbach's alpha values ranged from 0.64 to 0.90 and ICC values from 0.66 to 0.86.

CONCLUSION

This study provides preliminary evidence supporting validity and reliability of both the PDQ-39CSV and its briefer version.

Validity and reliability of the EQ-5D self-report questionnaire in Chinese-speaking patients with rheumatic diseases in Singapore

OBJECTIVE

We assessed the psychometric properties of a Singaporean Chinese version of the EQ-5D, a health-related quality of life (HRQoL) instrument.

MATERIALS AND METHODS

Consecutive outpatients with rheumatic diseases seen for routine follow-up consultations at the National University Hospital, Singapore were interviewed twice within 2 weeks using a standardised questionnaire containing the EQ-5D, the Short-Form 36 Health Survey (SF-36), the Learned Helplessness Subscale, a pain Visual Analogue Scale (VAS) and assessing demographic and psychosocial characteristics. To assess the validity of the EQ-5D, 13 hypotheses relating the EQ-5D self-classifier (5 dimensions) or visual analogue scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney U test, Kruskal-Wallis or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa.

RESULTS

Forty-eight subjects were studied (osteoarthritis: 16; rheumatoid arthritis: 22; systemic lupus erythematosus: 8; spondyloarthropathy: 2; female: 93.8%; mean age: 56.4 years). Seven of 13 a-priori hypotheses relating EQ-5D to external variables were fulfilled, supporting the validity of the EQ-5D. For example, subjects reporting moderate or extreme problems for EQ-5D dimensions generally had lower median SF-36 scores than those without such problems. Cohen's kappa for test-retest reliability of the self-classifier ranged from 0.41 to 1.00 (n = 42; median interval: 7 days, interquartile range: 7 to 11 days).

CONCLUSIONS

The Singaporean Chinese EQ-5D self-classifier appears to be a valid measure of HRQoL in Singaporeans with rheumatic diseases; however, the reliability of the EQ-VAS requires further investigation. These data provide a basis for further studies of the Singaporean Chinese EQ-5D.

Validity and reliability of the EQ-5D self-report questionnaire in English-speaking Asian patients with rheumatic diseases in Singapore

Validity and reliability of a Singaporean English EQ-5D self-report questionnaire (EQ-5D) were evaluated among consecutive outpatients with rheumatic diseases attending a tertiary referral hospital in Singapore (a multi-ethnic, urban Asian country). Subjects were interviewed twice within a 2-week period using a standardized questionnaire containing the EQ-5D, Short Form 36 Health Survey (SF-36) and assessing demographic and psychosocial characteristics. To assess validity of the EQ-5D, 13 hypotheses relating responses to EQ-5D dimension/Visual Analogue Scale (EQ-VAS) to SF-36 scores or other variables were examined using the Mann-Whitney test, Kruskal-Wallis test, or Spearman's correlation coefficient. Test-retest reliability was assessed using Cohen's kappa. Sixty-six subjects were studied (osteoarthritis: 9, rheumatoid arthritis: 26, systemic lupus erythematosus: 23, spondyloarthropathy: 8; female: 72.7%; mean age: 44.3 years). Ten of 13 a-priori hypotheses relating EQ-5D responses to external variables were fulfilled, supporting the validity of the EQ-SD. Cohen's kappa for test-retest reliability (n = 52) ranged from 0.29 to 0.61. The Singaporean English EQ-5D appears to be valid in measuring quality of life in Singaporeans with rheumatic diseases; however, its reliability requires further investigation. These data provide a basis for further studies assessing the validity of the EQ-5D in Singapore.

Acquisition of dominance status affects maze learning in mice

Learning is likely to be costly and thus subject to trade-off with other components of life history. An obvious prediction, therefore, is that investment in learning, and thus learning performance, will vary with individual life history strategy and the reproductive value of the learning outcome. We tested this idea in the context of social dominance in male laboratory mice, using a simple radial maze paradigm to compare the ability of high- and low-ranking male mice to track changing food location. We tested animals in randomly selected pairs before and after establishing aggressive rank relationships to distinguish intrinsic differences in learning ability from those attributable to acquiring high or low rank. There was no difference in learning between later dominants and subordinates prior to establishing rank relationships. After pairing, however, dominants showed a significantly greater percentage of correct responses, with the difference being greatest earlier in a sequence of trials. The percentage of correct responses also increased with the amount of aggression initiated during pairing. The results thus appeared to reflect a state-dependent change in learning associated with the aggressive social relationships formed during pairing.

[Study of direct determining animal and plant oil in sewage by ultraviolet spectrophotometry method]

In this paper, the trace oil in sewage have been emulsified with S-T emulsifier and determined by ultraviolet spectrophotometry. Under normal temperature, the oil even dispersed in sewage with S-T emulsifier. It is stable and direct determined without separation. The oil is from sewage. The linear range is 0-92 micrograms.mL-1, and rate of recovery is 89%-129%. The method is quick and simple.

Molecular characterization of a cryptic plasmid from Campylobacter jejuni

Campylobacter jejuni is a leading bacterial cause of human enterocolitis. Molecular genetic characterization of this pathogen has been hampered by the lack of genetic tools that are functional in this organism. Cloning vectors commonly used in other organisms usually do not replicate within C. jejuni. To develop a system for functional analysis of C. jejuni genes, a small plasmid (pCJ01) identified in a poultry isolate of C. jejuni was sequenced and characterized in this study. By using inverse PCR, the full sequence of pCJ01 was amplified and subsequently determined. Results indicate that pCJ01 is a circular molecule of 3212 bp, with a G + C content of 33.5%. A typical plasmid replication origin with iteron sequences is identified upstream of the DNA sequences encoding replication initiation proteins. Four open reading frames (ORFs) are present in pCJ01. ORF1 and ORF2 share high homology with the putative RepA and RepB proteins, respectively, of known C. coli plasmids. ORF3 and ORF4, of unknown function, do not exhibit homology with any sequences deposited in the GenBank database. Hydropathy analysis predicts that ORF3 and ORF4 contain multiple stretches of hydrophobic amino acids, suggesting that they may encode transmembrane proteins. Since pCJ01 is a small plasmid and can be readily prepared from C. jejuni, it may be modified for use in molecular characterization of C. jejuni virulence genes.

Oxidized LDL induces the expression of ALBP/aP2 mRNA and protein in human THP-1 macrophages

The adipocyte lipid-binding protein (ALBP/aP2) belongs to a multigene family of fatty acid and retinoid transport proteins. This protein is abundantly expressed in the cytoplasm and nuclear region of adipocytes and is postulated to serve as a lipid shuttle, solubilizing hydrophobic fatty acids and delivering them to the appropriate metabolic system for utilization. This report demonstrates that human cholesterol-loaded THP-1 macrophages express ALBP/aP2 and that its expression can be stimulated by oxidized low density lipoprotein (oxLDL). The increase in mRNA expression was paralleled by a similar increase in ALBP/aP2 protein. The increase in ALBP/aP2 mRNA and protein in oxLDL-stimulated THP-1 macrophages is concentration and time dependent and is inhibited by treatment of the cells with an antioxidant inhibitor of nuclear factor-kappaB (NF-kappaB), pyrrolidine dithiocarbamate (PDTC), and with protein kinase C (PKC) inhibitors bisindolylmaleimide I and Ro-31-8220. These results suggest that activation of both NF-kappaB and PKC signaling pathways is necessary for oxLDL-induced ALBP/aP2 gene expression in THP-1 macrophages and that the upregulation of the fatty acid carrier may be a necessary event in foam cell formation.

Specificity of damage recognition and catalysis of DNA repair

A common feature of DNA repair enzymes is their ability to recognize the damage independently of sequence in which they are found. The presence of a flipped out base inserted into the protein in several DNA-enzyme complexes suggests a contribution to enzyme specificity. Molecular simulations of damaged DNA indicate that the damage produces changes in DNA structure and changes the dynamics of DNA bending. The reduced bending force constant can be used by the enzyme to induce DNA bending and facilitate base flipping. We show that a thymine dimer (TD) containing DNA requires less energy to bend, lowering the barrier for base flipping. On the other hand, bending in DNA with U-G mismatch is affected only by a small amount and flipping is not enhanced significantly. T4 endonuclease V (endoV), which recognizes TD, utilizes the reduced barrier for flipping as a specific recognition element. In uracil DNA glycosylase (UDG), which recognizes U-G mismatches, base flipping is not enhanced and recognition is encoded in a highly specific binding pocket for the flipped base. Simulations of UDG and endoV in complex with damaged DNA provide insight into the essential elements of the catalytic mechanism. Calculations of pKas of active site residues in endoV and endoV-DNA complex show that the pKa, of the N-terminus is reduced from 8.01 to 6.52 while that of Glu-23 increases from 1.52 to 7.82. Thus, the key catalytic residues are in their neutral form. The simulations also show that Glu-23 is also H-bonded to O4' of the 5'-TD enhancing the nucleophilic attack on Cl and that Arg-26 enhances the hydrolysis by electrostatic stabilization but does not participate in proton transfer. In the enzyme-substrate complex of UDG, the role of electrostatic stabilization is played by His-268, whose pKa increases to 7.1 from 4.9 in the free enzyme. The pKa of Asp-145, the other important catalytic residue, remains around 4.2 in the free enzyme and in the complex. Thus, it can not act as a proton acceptor. In the complex the 3'-phosphate of uracil is stabilized next to Asp-145 by two bridging water molecules. Such a configuration activates one water molecule to act as a proton acceptor to produce a stabilizing hydronium ion and the other as a proton donor to produce the nucleophilic hydroxide. It appears that DNA glycosylases share commonalties in recognition of damage but differ in their catalytic mechanisms.

[Expression and significance of neuropeptide and neurotensin in the extract of platelet of chronic renal failure patients during hemodialysis]

The aim of this study was to investigate the change of neuropeptide Y(NPY) content and neurotensin (NT) content of the platelet from chronic renal failure (CRF) patients during hemodialysis (HD) and explore its mechanism of action. Platelet was separated from the patients' plasma and the NPY and and NT contents of the platelet and plasma were dynamically observed pre-HD and post-HD. 30 healthy people were chosen as the controls. The results showed the NPY and NT contents of the platelet extract were (58.18 +/- 21.29) ng/10(9) and (25.38 +/- 13.43) ng/10(9) respectively. The NPY content of the platelet extract of the CRF patients was obviously decreased and the NT content of the plasma was obviously increased however, the NT contents of the platelet extract and the plasma were both higher than those in the control group. The NPY content of the platelet extract and NT content of the plasma at the post-HD obviously increased as compared with pre-HD, but the NT content of the platelet extract and the NPY content of the plasma obviously decreased. There was an obvious correlation between NPY and NT. The authors conclude that during the period of CRF, the immunoreactions which mainly involve bio-active substances such as NPY, NT and 5-hydroxytryptamine released by the platelet to interfer the vasoconstrictive effect are the main pathologic factors to induce renal hypertensin and renal vasospasm.

Specificity and catalysis of uracil DNA glycosylase. A molecular dynamics study of reactant and product complexes with DNA

The structure of uracil DNA glycosylase (UDG) in complex with a nonamer duplex DNA containing a uracil has been determined only in the product state. The reactant state was constructed by reattaching uracil to the deoxyribose, and both complexes were studied by molecular dynamics simulations. Significant changes in the positions of secondary structural elements in the enzyme are induced by the hydrolysis of the glycosidic bond. The simulations show that the specificity of the uracil pocket in the enzyme is largely retained in both complexes with the exception of Asn-204, which has been identified as a residue that contributes to discrimination between uracil and cytosine. The hydrogen bond between the amide group of Asn-204 and O(4) of uracil is disrupted by fluctuations of the side chain in the reactant state and is replaced by a hydrogen bond to water molecules trapped in the interior of the protein behind the uracil binding pocket. The role of two residues implicated by mutation experiments to be important in catalysis, His-268 and Asp-145, is clarified by the simulations. In the reactant state, His-268 is found 3.45 +/- 0.34 A from the uracil, allowing a water molecule to form a bridge to O(2). The environment in the enzyme raises the pK(a) value of His-268 to 7.1, establishing a protonated residue for assisting in the hydrolysis of the glycosidic bond. In agreement with the crystallographic structure, the DNA backbone retracts after the hydrolysis to allow His-268 to approach the O(2) of uracil with a concomitant release of the bridging water molecule and a reduction in the pK(a) to 5.5, which releases the proton to the product. The side chain of Asp-145 is fully solvated in the reactant state and H-bonded through a water molecule to the 3'-phosphate of uridine. Both the proximity of Asp-145 to the negatively charged phosphate and its pK(a) of 4.4 indicate that it cannot act as a general base catalyst. We propose a mechanism in which the bridging water between Asp-145 and the 3'-phosphate accepts a proton from another water to stabilize the bridge through a hydronium ion as well as to produce the hydroxide anion required for the hydrolytic step. The mechanism is consistent with known experimental data.

Twice weekly tuberculosis preventive therapy in HIV infection in Zambia

BACKGROUND

A randomized double-blind placebo-controlled trial was conducted to estimate the efficacy of preventive therapy for tuberculosis (TB) in HIV-infected adults in Lusaka, Zambia. The main outcome measures were the incidence of TB, mortality and adverse drug reactions.

METHODS

During a 2 year period, 1053 HIV-positive individuals without evidence of clinical TB were randomly assigned to receive 6 months of isoniazid twice a week (H), or 3 months of rifampicin twice a week (R) plus pyrazinamide (Z), or a placebo. Therapy was taken twice a week and was self administered. Subjects presenting with symptoms during the follow-up period were investigated for TB.

RESULTS

The 1053 subjects in the study were followed up for a total of 1631 person-years (median = 1.8 years). Twenty-nine subjects were taken off treatment as a result of adverse drug reactions. A total of 96 cases of TB/probable TB (59 TB and 37 probable TB) were diagnosed during the study period and 185 deaths were reported. One hundred and fifteen subjects (11%) did not return to the study clinic at any time after enrolment. The incidence of TB was lower in those subjects on preventive therapy (H and RZ groups combined) compared with those on placebo (rate ratio = 0.60, 95% CI: 0.36-1.01, P = 0.057), as was the incidence of TB/probable TB (rate ratio = 0.60, 95% CI: 0.40-0.89, P = 0.013). The effect of preventive therapy was greater in those with a tuberculin skin test (TST) of 5 mm or greater, in those with a lymphocyte count of 2x10(9)/l or higher, and in those with haemoglobin of 10 g/dl or higher. There was no difference in mortality rates between the preventive therapy and placebo groups. The effect of preventive therapy declined after the first year of the study so that by 18 months the rates of TB in the treated groups were similar to that in the placebo group.

CONCLUSION

This study has demonstrated that preventive therapy with either twice weekly isoniazid for 6 months or a combination of rifampicin and pyrazinamide for 3 months reduced the incidence of TB in HIV-infected persons in Zambia. No effect was observed on mortality. The effect was greatest in persons who had a positive TST or a lymphocyte count of 2x10(9)/l or greater, indicating that preventive therapy may be more effective in people with less advanced immunosuppression. The limited duration of the protective effect reported in this study raises the question of the need for lifelong preventive therapy or re-prophylaxis.

Respiratory syncytial virus infection in children with acute respiratory infections in Zambia

Epidemiological research on respiratory syncytial virus (RSV) infections in children was carried out at the Virology Laboratory, University Teaching Hospital (UTH), in Lusaka, Zambia, from January-December 1996. Specimens including 736 nasal washings and 2424 throat swabs were collected from children with acute respiratory infections (ARI) and tested for RSV by enzyme immunoassay and by virus isolation. RSV was isolated in 62 (4.1%) of 1496 throat swabs collected from March to September and was detected in 99 (16.3%) of 609 nasal washings from March to November. The average RSV isolation rate was 2.6% and the average RSV detection rate was 13.5%. The highest RSV isolation (8.1%) and detection (30.5%) rates were in June 1996. RSV antibody in the 278 serum specimens collected from Zambian children, who were hospitalized in the paediatric ward, UTH, was detected using a standard neutralization test. The antibody positive rate was 60-80% in children > 4 years. It is evident that RSV is one of the main causal agents of ARI in children in Zambia.

[Hyaluronic acid and laminin in patients with ischemic necrosis of femoral head]

To study the course and clinical significance of hyaluronic acid (HA) and laminin(LN), the main components of extracellular matrix in ischemic necrosis of femoral head(INFH), the quantities of HA and LN were measured by radioimmunoassay in 45 patients suffering from INFH with different pathogenesis, and in 30 normal subjects(NS). The results showed that the level of HA in patients with INFH was markedly higher than that of NS group(t = 3.29, P < 0.01). The patients with hormone type INFH had the highest level of HA(t = 3.62, P < 0.01). The level of LN in patient with INFH was significantly higher than that of NS group(t = 2.84, P < 0.01). The increased levels of HA and LN were positively correlated with the development of the disease. These suggest that quantity analysis of HA and LN may be used as a good indicator in early diagnosis and prognosis of INFH.

Spread of Neisseria meningitidis group A clone III-I meningitis epidemic into Zambia

The epidemic of Neisseria meningitidis group A clone III-I strain began with the 1987 outbreak in Mecca, Saudi Arabia. Intense epidemics in African countries occurred the following year. Clone III-I was first isolated from Africa in 1988 in Chad, followed by epidemics in Ethiopia (1989), Kenya and Tanzania (1989), and The Central African Republic (1992). We report an epidemic of Neisseria meningitidis group A clone III-I afflicting Zambia during a 2-year period (April 1992-May 1994). This extension of the 'meningitis belt' southwards into Central Africa is cause for concern. Active surveillance for this disease should be carried out by all African countries, even those outside the well described sub-Saharan 'meningitis belt'.

Epidemiology of rotavirus diarrhoea in Africa: a review to assess the need for rotavirus immunization

Rapid progress towards the development of rotavirus vaccines has prompted a reassessment of the disease burden of rotavirus diarrhoea in developing countries and the possible impact of these vaccines in reducing diarrhoeal morbidity and mortality among infants and young children. We examined the epidemiology and disease burden of rotavirus diarrhoea among hospitalized and clinic patients in African countries through a review of 43 published studies of the etiology of diarrhoea. The studies were carried out from 1975 through 1992, and only those in which a sample of more than 100 patients with diarrhoea were specifically screened for rotavirus by using an established diagnostic test were included. Rotavirus was detected in a median of 24% of children hospitalized for diarrhoea and in 23% who were treated as outpatients; 38% of the hospitalized patients with rotavirus were < 6 months and 81% were < 1 year of age. Rotavirus was detected year-round in nearly every country and generally exhibited distinct seasonal peaks during the dry months. In 5 countries where rotavirus strains had been G-typed, 74% of strains were of one of the four common serotypes (G1 to G4), G1 was the predominant serotype, and 26% were non-typeable. This cumulative experience from 15 African countries suggests that rotavirus is the most important cause of severe diarrhoea in African children and that most strains in circulation today belong to common G types that are included in reassortant vaccines. Wherever large numbers of cases of rotavirus diarrhoea occur early in infancy, immunization at birth may protect the children before their first symptomatic infection.

[HPLC determination of diltiazem in human serum and its pharmacokinetic parameters]

A simple and sensitive reversed-phase liquid chromatographic method has been developed and validated for the analysis of diltiazem in human serum and the study of pharmacokinetics of the drug in human body. Diltiazem and diazepam (internal standard) in serum were extracted with hexane-chloroform-isopropanol (60:40:5, V/V), and then measured by HPLC using a Spherisorb C18 column as stationary phase and a methanol-water triethylamine as mobile phase. Diltiazem was quantified by ultraviolet absorbance at 239 nm. The method proved to be linear in the clinical range of 15-300 microg/L with a regression coefficient of 0.9997. The lower limit of detection of diltiazem in serum was 3 microg/L. Intra-day and inter-day coefficients of variation of assay for diltiazem in serum were 3.5%-6.8% (n=7) and 6.2%-8.4% (n=5), respectively. The recoveries of diltiazem were 91%-104% for serum. The method has been used to determine diltiazem in serum samples from eight volunteers and provided data on the pharmacokinetics of the drug. The results inferred that diltiazem is absorbed rapidly and had a relatively short half-life time in healthy individuals. The data obtained was fitted with PKBP-N1 program on computer to study the pharmacokinetics. The results showed that the peak level in serum averaged 118.5 microg/L +/- 14.3 microg/L at 3.1 h +/- 0.4 h, and the areas under the drug concentration curves (AUC) was 793.1 microg x h/L +/- 83.1 microg x h/L.

[Determination of amoxicillin in human plasma by high performance liquid chromatography and its pharmacokinetics]

A rapid and sensitive assay for amoxicillin in human plasma has been developed using reversed phase high performance liquid chromatography. Plasma samples were prepared for analysis by addition of internal standard (tinidazole) followed by protein precipitation with HClO4. A YWG C18H37 column as stationary phase and a 0.033 mol.L-1 phosphate buffer (pH 7.2)--methanol mixture (85:15) as mobile phase were used with the UV detector set at 229 nm. The calibration curve was linear in the range from 0.2 microgram.ml-1 to 20.0 micrograms.ml-1 with gamma > 0.999. The analytical recovery of amoxicillin from plasma was > 86.7%. The relative standard deviations for within-day and between-day were < 5.48% and < 8.29%, respectively. Following oral administration of 500 mg in human volunteers, the peak levels of amoxicillin in plasma averaged 6.88 +/- 2.25 micrograms.ml-1 at 84.4 +/- 21.1 min. The mean half life time for amoxicillin was 62.8 +/- 14.6 min.

Geographical distribution of HIV-1 group O viruses in Africa

OBJECTIVE

To determine to what extent HIV-1 group O strains are present in different African countries.

MATERIALS AND METHODS

A total of 14,682 samples of sera from a range of patients from 12 different African countries were tested. All the sera were tested with an enzyme-linked immunosorbent assay (ELISA) using a combination of V3 peptides from ANT-70 and MVP-5180. Samples reactive in ELISA were retested in a line immunoassay (LIA-O). Samples reactive in ELISA were also retested with an in-house Western blot to determine the presence of antibodies to gp120 of HIV-1 ANT-70. Polymerase chain reaction was performed on HIV-1 group O and group O indeterminate sera.

RESULTS

Of all the sera samples tested, only 19 sera had antibodies to group O V3 peptides exclusively and 46 were indeterminate for group O infection in LIA-O. The highest prevalence of HIV-1 group O infection among HIV-positive sera was observed in Cameroon (2.1%) and neighbouring countries, 1.1% in Nigeria and 0.9% in Gabon. The lowest rates were seen in west Africa: 0.07% in Senegal, 0.14% in Togo, 0.16% in Chad and 0.3% in Niger. Group O sera were observed in almost all the population categories tested. The ANT-70 V3 peptide in LIA-O was reactive with all of the sera considered to be HIV-1 group O antibody positive by LIA, versus 78.9% for the MVP-5180 peptide. Thirteen out of 19 group O samples of sera were tested in PCR. Eight samples were identified as group O by specific group O pol and/or V3 primers; in the remaining five samples no HIV RNA could be detected. Of the indeterminate sera samples, two were identified as group O.

CONCLUSION

In eight of the 12 countries tested, antibodies to group O viruses were identified. Numbers of HIV-1 group O viruses are low. Their presence is not restricted to Cameroon and neighbouring countries but can also be found in west and south-east Africa.

Neopterin, beta 2-microglobulin, and acute phase proteins in HIV-1-seropositive and -seronegative Zambian patients with tuberculosis

Neopterin is a biochemical marker for the activation of the cell-mediated immune system. We measured neopterin, beta 2-microglobulin, and acute phase proteins in 31 HIV-seropositive and -seronegative Zambian patients with tuberculosis, using stored sera that had been obtained at the beginning and at end of antituberculosis treatment. In both HIV-seropositive and -seronegative patients neopterin and acute phase proteins were elevated when tuberculosis was initially diagnosed and fell during treatment. In contrast, the mean beta 2-microglobulin level increased during antituberculous therapy in the HIV-seropositive group. Serum neopterin levels at diagnosis were correlated with other parameters of disease activity (fever, anemia, and weight loss). In both groups, patients with persistently elevated neopterin levels at the end of treatment were more likely to suffer relapse of tuberculosis or other adverse health events in the subsequent follow-up period. Neopterin can be used to monitor the response to antituberculous therapy in both HIV-seropositive and -seronegative patients and may have a prognostic value for the patients' wellbeing in the follow-up period.

The prevalence and aetiology of persistent diarrhoea in adults in urban Zambia

As the AIDS pandemic has spread, diarrhoea in adults has become a major burden on health care institutions in central Africa and on the families of sufferers. In order to assess the magnitude of the problem, we carried out a survey of households in a high population density township of Lusaka to determine the prevalence of persistent diarrhoea in adults. We also carried out a study of the causes of persistent diarrhoea in patients attending the University Teaching Hospital, Lusaka. The community survey assessed 460 households, representing a sample of 1440 adults. 94 adults were reported as having had diarrhoea in the 2 weeks prior to the survey, implying an attack rate of 1.74 per adult per year. Of these 94 cases, six had diarrhoea of between 2 and 4 weeks duration, and ten had diarrhoea of over 4 weeks duration. In the hospital study, 75 (97%) out of 77 patients with diarrhoea of over 1 months' duration were HIV seropositive; potentially pathogenic parasites were found in 61/75 (81%) of seropositives. This information indicates that persistent diarrhoea in adults, mostly related to HIV infection, is likely to be an important and growing reservoir of enteric pathogens and represents a significant burden on hospitals and relatives. This emerging problem in sub-Saharan Africa may foreshadow developments in other continents.