The effect of antibacterial agents on plasma vitamin C levels.

Previous report on the estimation of plasma ascorbic acid levels in patients with chronic osteomyelitis indicated that the plasma ascorbic acid level is reduced in patients on antibiotics. The plasma study of the effects of anti-bacterial agents on plasma ascorbic acid in vitro, was carried out to substantiate the hypothesis than these agents lower plasma ascorbic acid levels. Increasing amounts of each of seven anti-bacterial agents: ampicillin, chloramphenicol, cefotaxime, gentamycin, benzyl and procaine penicillin combination (seclopen), co-trimoxazole, and streptomycin significantly (P < 0.01, r = -0.9587) reduced plasma vitamin C levels in vitro. There was moderate but insignificant reduction in plasma vitamin C levels with clindamycin (r = -0.799). The reduction of the plasma vitamin C levels observed in the presence of the eighth anti-bacterial agent, clindamycin, lacked significance (r = -0.799). The cause of this reduction of plasma vitamin C levels by anti-bacterial agents in vitro is not yet understood. A supplement of vitamin C may be required in patients on anti-bacterial agents.

Effects of an aqueous extract of cotton seed (Gossypium barbadense Linn.) on adult male rats.

Twenty adult male rats per group in 4 treatment groups were injected intraperitoneally at 08.00 hours with 0.1 ml of an aqueous cotton seed extract (Gossypium barbadense Linn.) (Malvaceae) in concentrations of (a) 105.25, (b) 21.21, (c) 4.65, (d) 2.325 mg ml-1 (kg body weight)-1, respectively. A fifth group (control) was given 0.1 ml of pyrogen free distilled water per rat. Five rats per treatment group were sacrificed at 2, 8, 24 and 168 hours respectively after treatment. Plasma follicle stimulating hormone (FSH) and luteinizing hormone (LH) showed no change. Plasma testosterone was lower (p less than 0.05) than that of control at 2 and 8 hours, with recovery by 168 hours post treatment. Plasma creatinine was raised by 2 hours, with recovery by 8 hours. Plasma urea rose gradually but persistently to a maximum of 168 hours. Plasma aspartate (AST) and alanine (ALT) transaminases were significantly higher (p less than 0.001) than that of controls throughout the study. Testicular histology showed early germ cell disorganization followed by progressive fibrosis (sperm cytoskeleton) by 24 hours. There was evidence of recovery by 168 hours. It is concluded that aqueous extract of cotton seed meal contains substances that can rapidly cause damage to testicular, liver, kidney and muscular tissues.

Steroidal contraceptives and changes in individual plasma phospholipids: possible role in thrombosis.

The changes in the levels of individual phospholipids were studies in women during prolonged use of three types of steroidal contraceptive preparation: high-dose combined pills (Noriday 1 + 50 Fe); low-dose combined pills (Nominest Fe) and progestin-only injectables (Depo-Provera). Women on high-dose combined pills had significantly higher (p less than 0.05) mean lysophosphatidylcholine (LPC), sphingomyelin (SPH), phosphatidylserine (PS) and phosphatidylethanolamine (PE) levels, respectively, than the women on low-dose combined pills, progestin-only injectables and the controls, respectively. Women on low-dose combined pills had significantly lower (p less than 0.01) mean LPC and PS levels, respectively, than the controls, while women on progestin-only injectables had significantly lower (p less than 0.01) mean PS and PE levels, respectively, than the controls. Based on the reported high activities of PS and PE in hemostasis, the PE/total plasma phospholipids, PS/total plasma phospholipids and the sum of PE and PS/total plasma phospholipids ratios were calculated to assess the possible overall effect of the changes in plasma phospholipids in steroidal contraceptive users. The results obtained using these indices agree with some earlier reports of an estrogen dose-dependent risk/incidence of thrombosis in steroidal contraceptive users. It is concluded that the observed dose-dependent estrogen-induced alterations in phospholipids, and, most especially, the PE and PS fractions may bear a relationship with thrombotic conditions.