Microbiological and biochemical characterization of cassava retting, a traditional lactic Acid fermentation for foo-foo (cassava flour) production.

The overall kinetics of retting, a spontaneous fermentation of cassava roots performed in central Africa, was investigated in terms of microbial-population evolution and biochemical and physicochemical parameters. During the traditional process, endogenous cyanogens were almost totally degraded, plant cell walls were lysed by the simultaneous action of pectin methylesterase and pectate lyase, and organic acids (C(inf2) to C(inf4)) were produced. Most microorganisms identified were found to be facultative anaerobes which used the sugars (sucrose, glucose, and fructose) present in the roots as carbon sources. After 24 h of retting, the fermentation reached an equilibrium that was reproducible in all the spontaneous fermentations studied. Lactic acid bacteria were largely predominant (over 99% of the total flora after 48 h) and governed the fermentation. The epiphytic flora was first replaced by Lactococcus lactis, then by Leuconostoc mesenteroides, and finally, at the end of the process, by Lactobacillus plantarum. These organisms produced ethanol and high concentrations of lactate, which strongly acidified the retting juice. In addition, the rapid decrease in partial oxygen pressure rendered the process anaerobic. Strict anaerobes, such as Clostridium spp., developed and produced the volatile fatty acids (mainly butyrate) responsible, together with lactate, for the typical flavor of retted cassava. Yeasts (mostly Candida spp.) did not seem to play a significant role in the process, but their increasing numbers in the last stage of the process might influence the flavor and the preservation of the end products.

Hearing preservation after acoustic neurinoma operation.

Between 1981 and 1984, 44 patients underwent acoustic neurinoma removal by a posterior cranial fossa approach with an attempt to preserve hearing. Seven tumors were small (less than 20 mm), 28 were medium (20 to 40 mm), and 9 were large (greater than 40 mm). Preoperatively, 4 patients had normal hearing, 15 had serviceable hearing, 10 had poor hearing, and 15 had no hearing. Postoperative hearing was preserved in 11 cases. Of the 19 patients with normal or serviceable hearing, 8 (42%) had serviceable hearing preserved postoperatively. Hearing preservation was achieved in 43% of the patients with small tumors, 25% of those with medium tumors, and 11% of those with large tumors. This study confirms the value of the suboccipital approach, which can be used in an attempt to preserve hearing whenever the patient has serviceable hearing preoperatively and whenever the tumor size makes it feasible.

[Preservation of hearing in surgery of acoustic neuroma]. / La préservation de l'audition dans la chirurgie du neurinome de l'acoustique.

Between 1981 and 1984, 44 patients underwent acoustic neuroma removal by a posterior cranial fossa approach in an attempt to preserve hearing. 7 tumors were small (less than 20 mm), 28 were medium (20 to 40 mm) and 9 large (greater than 40 mm). Of these 44 patients, 4 had normal hearing preoperatively, 15 had serviceable hearing, 10 poor hearing and 15 no hearing. Postoperative hearing was preserved in 11 cases. Of the 19 patients with normal or serviceable hearing, 8 (42%) had serviceable hearing preserved postoperatively. Hearing preservation was achieved in 43% of the cases of small tumors, 25% of those medium tumors and 11% with large tumors. This study confirms the value of the suboccipital approach, which can be used in an attempt to preserve hearing whenever the patient has serviceable hearing preoperatively and whenever the tumor size makes in feasible.

Natural history of human immunodeficiency virus infection in Zaire.

The natural history of human immunodeficiency virus (HIV) infection in Zaïre was determined by identifying in October, 1984, 125 seropositive hospital personnel without signs or symptoms and 145 age and sex matched seronegative controls from the same population. Between July, 1985, and February, 1986, 67 seropositives, including 38 men and 29 women, and 113 seronegatives were interviewed and examined by an observer who did not know their serological status. The acquired immunodeficiency syndrome (AIDS) had developed in 1 seropositive and no seronegatives (rate difference, 1.3/100 person-years [py]; 95% confidence interval 0-3.3/100 py); AIDS-related complex or generalised lymphadenopathy had developed in 8 seropositives (12%) and 1 seronegative (1%) (rate ratio, 13.2; 95% confidence interval 1.3-134.6); and minimal lymphadenopathy had developed in 19 seropositives (28%) and 8 seronegatives (7%) (rate ratio, 3.9; 95% confidence interval 1.8-8.4). These data provide the first estimates for rates of progression to AIDS or AIDS-related conditions among healthy HIV seropositive heterosexual adults. Rates observed in this study are similar to those reported in US or European homosexual or bisexual men.

The use of traditional and modern methods of fertility control in Kinshasa, Zaire.

Abstract The practice of post-partum abstinence has been a long-standing tradition in many societies of tropical Africa, yet recent research suggests an erosion of the taboo on post-partum sexual relations as a means of fertility control. The current study among women in the lower income groups in Kinshasa, Zaire, provides evidence of this. There is strong motivation toward child-spacing, as shown by 80 per cent of the women who reported to be currently practising some means of fertility control: 73 per cent with traditional methods, only 7 per cent with modern contraceptives. There appears to be some carry-over of traditional practice, in that abstinence is related to the age and nursing status of the last born child. However, the most widely practised method is withdrawal. This suggests a desire on the part of this population for alternatives to abstinence, an issue with important implications for future family planning programs in Zaire.