Environmental degradation of microbial polyhydroxyalkanoates and oil palm-based composites.

This paper investigates the degradation of polyhydroxyalkanoates and its biofiber composites in both soil and lake environment. Time-dependent changes in the weight loss of films were monitored. The rate of degradation of poly(3-hydroxybutyrate) [P(3HB)], poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-23 mol% 4HB)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-9 mol% 3HV-co-19 mol% 4HB)] were investigated. The rate of degradation in the lake is higher compared to that in the soil. The highest rate of degradation in lake environment (15.6% w/w week(-1)) was observed with P(3HB-co-3HV-co-4HB) terpolymer. Additionally, the rate of degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-38 mol% 3HV)] was compared to PHBV biofiber composites containing compatibilizers and empty fruit bunch (EFB). Here, composites with 30% EFB displayed the highest rate of degradation both in the lake (25.6% w/w week(-1)) and soil (15.6% w/w week(-1)) environment.

Solvent effects on OH stretching frequencies for 1-arylallyl alcohols.

A series of 1-arylallyl alcohols were prepared and its OH stretching frequencies measured in 20 different non-HBD solvents at room temperature. It is noticed that the observed stretching bands were highly sensitive to the nature of the solvents. Multiple parameter equations were applied to investigate the solvent effects on the O-H stretching frequency. The most significant solvent parameters were the nucleophilicity measuring parameter (B) and Gutmann donor number (DN), whilst the electrophilicity measuring parameter (E) is not significant.

[Gibbs-Sampler approach for meta-analysis of multiple clinical trials using generalized linear model with random-effects].

OBJECTIVE: To investigate the use of the Gibbs-Sampler method in evaluating the relationship between clinic events and health risks in a meta-analysis of multiple clinical trials. METHODS: By using a generalized linear model with random-effects, Gibbs-Sampler technique was used in a meta-analysis of multiple clinical trials of angiotensin converting enzyme (ACE) inhibitors in patients with myocardial infarction (MI). RESULTS: When heterogeneity across different trials can not be ignored, compared with the classic method, the odds ratio of relative reinfarction risk estimated by the Gibbs-Sampler method would have less variation. The gain in the reduction of variation in estimate of the overall odds ratio was 9.52%. CONCLUSION: Implementation of the Gibbs-Sampler technique in meta-analysis of multiple clinical trials has the potential of reducing the inaccuracy caused by heterogeneity across trials.

Efficacy of Cymelarsan in the treatment of natural chronic Trypanosoma evansi infection in camels in the Sudan.

The efficacy of Cymelarsan, administered by intramuscular (i/m) injection in the treatment of chronic cases of camel trypanosomosis due to Trypanosoma evansi, was tested under controlled laboratory conditions. It was confirmed that Cymelarsan is a safe drug for use in dromedary camels when administered i/m at dose rates of 0.25 or 0.50 mg/kg body weight. During the 90 days post-treatment no relapses occurred at either dose rate. Hence, the drug was found to be fully effective against the chronic form of the natural disease. A dose of 0.25 mg/kg body weight of Cymelarsan given i/m is recommended.

Trends in survival of Danish AIDS patients from 1981 to 1989.

Length of survival was analysed in relation to year of diagnosis, AIDS-indicative disease, age, risk behaviour, zidovudine therapy, and CD4 cell count and serum immunoglobulin (Ig) levels at the time of diagnosis in a group of 231 consecutive adult Danish AIDS patients reported before 1 January 1988. The cumulative survival rate was 53% (95% confidence interval 47-59%) at 1 year, 29% (22-36%) at 2 years and 18% (10-26%) at 3 years. Length of survival increased significantly (P less than 0.001) over time for patients who were initially diagnosed with Pneumocystis carinii pneumonia (PCP), 17% (3-31%) at 2 years prior to 1986, 32% (16-49%) in 1986 and 52% (34-69%) in 1987, whereas survival remained stable for patients with other AIDS-indicative diseases. Survival was similar for patients who were diagnosed with Kaposi's sarcoma alone and PCP alone. Independent predictors of a shortened survival were a CD4 cell count less than 200 x 10(6)/l, a serum IgA level greater than 4 g/l, and an initial diagnosis with opportunistic infections other than PCP. In addition, the multivariate analysis suggested an improved survival in recent years for patients diagnosed with PCP, independent of other factors examined. We conclude that length of survival in AIDS patients is highly variable. Determinants of progression include CD4 cell count, serum IgA level, and presenting disease. Survival has increased markedly for patients with PCP and median survival now exceeds 24 months.

Opportunistic infections and malignancies in 231 Danish AIDS patients.

We analysed cumulative disease frequencies in the first 231 adult Danish AIDS patients with life tables. There was a certain hierarchical pattern in the occurrence of complicating diseases. Herpes zoster, Kaposi's sarcoma and Pneumocystis carinii pneumonia were early manifestations, whereas diseases caused by cytomegalovirus and atypical mycobacteria tended to occur later in the course of AIDS. Compared with all other AIDS patients, homosexual men were more likely to develop Kaposi's sarcoma, cytomegalovirus chorioretinitis and mucocutaneous herpes simplex virus infection. The proportion of patients who developed particular diseases changed with calendar time. Most striking was a three to fourfold decrease in diseases caused by cytomegalovirus. In conclusion, the study showed that disease frequencies in patients with AIDS may vary with the patients risk behaviour and duration of AIDS, and that the frequencies of particular diseases may change with calendar time.

[Plasmapheresis in the treatment of peripheral HIV neuropathy]. / Plasmaferesebehandling af perifer HIV-neuropati.

Peripheral neuropathy following HIV infection is frequently seen among HIV-positive-, ARC- and AIDS patients who often complain of debilitating paresthesias. Indirect immunofluorescence technique showed antibodies directed either to myelin and/or axons and to endothelial cells of the blood vessels within the nerve tissue. Sural nerve biopsies from five patients showed demyelination, axonal degeneration and perivascular cellular infiltration. Two of the patients had nuclear inclusions and high anti-CMV titer. Plasma exchange was undertaken on five HIV infected patients which resulted in complete disappearance of symptoms in three, incomplete remission in one and no effect in one patient. The finding of autoantibodies against different nerve tissue components, cellular infiltration, positive effect of the plasma exchange and relapse suggests that autoimmunity may play a pathogenetic role in some of the HIV infected patients with peripheral neuropathy.

Anti-corticosteroid antibodies in AIDS patients.

Patients suffering from AIDS tend to have symptoms that resemble those encountered in adrenocortical insufficiency. Serum sodium concentrations and blood pressure values were monitored and found to be subnormal, despite the fact that renin activity and aldosterone levels were either normal or elevated. We report the presence of autoantibodies directed against hydrocortisone among such AIDS patients. Indirect immunofluorescence technique using patients' sera and adrenal glands from AIDS patients as antigen showed antibodies to adrenocortical cells in sera from 9 of the 12 AIDS patients and in none from patients with autoimmune diseases and viral diseases or healthy blood donors. No similar reaction was seen in normal human or monkey adrenal glands. An ELISA technique was developed using hydrocortisone as antigen and using this technique 45% of the AIDS patients were found to have antibodies to hydrocortisone. It is possible that anti-corticosteroid antibodies (ACSA) may play a role in the pathophysiology of the Addison's like syndrome seen in terminal phases of AIDS.

Yield of diagnostic tests for opportunistic infections in AIDS: a survey of 33 patients.

To examine the therapeutic consequences of diagnostic tests for AIDS-related infections, case records from 33 deceased AIDS patients were reviewed; 23 were autopsied. Determination of serum antibody titres was not important. In particular, there was no relation between titres and isolation of cytomegalovirus (CMV); isolation attempts or possibly antigen determination would be better. Samples for CMV isolation were obtained from 31 patients; only 7 were negative. Blood, faeces, and particularly sputum cultures gave a low yield; the number of such examinations could be reduced considerably. However, 4/7 disseminated infections with atypical mycobacteria were only revealed at autopsy, despite numerous cultures in vivo. Liver biopsies were not helpful. Diagnostic procedures for Pneumocystis carinii pneumonia by lung biopsy caused pneumothorax in 3/15 patients; bronchoalveolar lavage or treatment/prophylaxis without diagnosis could be considered. In 8 autopsies, microscopy was suggestive of cerebral toxoplasmosis, but only 1 patient had presented important clinical symptoms. We suggest a schedule with regular microbiologic and parasitic examinations and few antibody tests, but with more antigen tests.