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.

[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.