Traditional preparation and uses of cassava in Nigeria

Various methods of cassava preparation are practised by different ethnic groups in Nigeria. These methods involve peeling cassava roots, soaking roots in streams, grating cassava, and pressing grated cassava. Other methods include heating sieved, grated cassava, boiling peeled cassava roots, and pounding boiled or dried cassava roots. The traditional, cassava-based products aregari, fufu, akpu, cassava flour, edible starch, and tapioca. Detoxification of fresh cassava roots is partly achieved through cell rupture during cutting and grating, soaking in running or standing water in earthen pots for 3–5 days, heating, drying, and boiling.     

Partial preference of insects for the male flowers of an annual herb

Summary The flowers of the annual herb Impatiens capensis have distinct male and female phases. The male phase lasts four times as long as the female phase, and male flowers contain about 50% more nectar than female flowers. This suggests that the bulk of allocation to the flower is designed to ensure the dispersal of pollen rather than the fertilization of ovules. Honeybees, wasps and bumble bees all land on male flowers more often than would be expected by chance, and, having landed, wasps and bumble bees are more likely to enter a male flower than a female flower. The frequency of male flowers in the diet therefore exceeds their frequency in the population. This preference, although strong and consistent, is only partial, since some female flowers are included in the diet. We propose two hypotheses to account for the observed partial preference, the first based on competition between bees for flowers, and the second asserting that the bees detect nectar levels directly without using floral gender as a cue. The results of an experiment in which the most obvious gender cue, the androecium, was removed are consistent with the second hypothesis.     

Separate Branches of the uvr Gene-Dependent Excision Repair Process in Ultraviolet-Irradiated Escherichia coli K-12 Cells; Their Dependence upon Growth Medium and the polA, recA, recB, and exrA Genes

The extent of repair of single-strand breaks (incision breaks) induced in the deoxyribonucleic acid (DNA) of Escherichia coli K-12 cells by the uvr gene-dependent excision repair process after ultraviolet (UV) radiation was determined in the wild-type, polA1, recA56, recB21, and exrA strains. The wild-type strain repaired all incision breaks after incident doses of UV radiation (254 nm) of approximately 60 J m(-2) or less when incubated in growth medium, or approximately 15 J m(-2) or less when incubated in buffer. The polA1 strain repaired the incision breaks completely after incident doses of approximately 12 J m(-2) or less when incubated in growth medium, or after approximately 4 J m(-2) when incubated in buffer. The recA13, recB21, and exrA strains showed essentially complete repair after incident doses of 10 to 15 J m(-2) whether the cells were incubated in buffer or growth medium. These results suggest that the uvr gene-dependent excision repair process may be divided into two branches, one which is dependent on the presence of growth medium and also the rec(+)exr(+) genotype, and a second which can occur in buffer (growth medium-independent) and is largely dependent on DNA polymerase I. The presence of chloramphenicol in the growth medium resulted in an inhibition of the growth medium-dependent repair occurring in wild-type and polA1 cells and had little or no effect on the extent of repair observed in recA56, recB21, or exrA cells. The similarities between the growth medium-dependent and -independent branches of excision repair and two known processes for the repair of X-ray-induced single-strand breaks are discussed.     

The Clinical Spectrum of Renal Insufficiency During Acute Glomerulonephritis in the Adult

Twenty-seven adults with acute poststreptococcal glomerulonephritis were divided into two groups according to the severity of reduction in renal function: (1) 14 patients with mild depression of renal function, and (2) 13 patients with more severe renal insufficiency. In the first group the outcome was favourable, with complete clinical recovery in 11 patients. Only two patients in the second group have recovered. Five have died of renal failure and in six the chronic stage has developed. The most notable histopathological lesion observed in this group of patients was severe proliferative glomerulonephritis with a large number of epithelial crescents. According to the mode of development and time of onset of renal failure, these 13 patients could be divided into three sub-groups: (1) early renal failure without oliguria (three patients), (2) early renal failure with severe oliguria or anuria (three patients) and (3) delayed renal failure (seven patients).Although there are exceptions, the development of renal insufficiency in an adult patient suffering from acute glomerulonephritis is usually associated with a guarded prognosis.     

Incidence and duration of lactation and lactational performance among mothers of low-birth-weight and term infants.

The lactation experience of 55 mothers of 62 infants of low birth weight (2500 g or less) was prospectively compared with that of 55 mothers of 55 control infants (38 weeks'' gestation or more, birth weight more than 2500 g) born at the same institution. The incidence rates of lactation at delivery were 73% for the control group and 58% for the low-birth-weight group; 11% of the infants of low birth weight fed breast milk were never put to the breast. The mean age at first suckling was 277.3 hours in the low-birth-weight group, compared with 3.3 hours in the control group (p less than 0.0005). At first suckling 81% of the low-birth-weight infants and 25% of the control infants sucked poorly or refused the breast (p less than 0.001). At discharge 65% of the breast-milk-fed control infants were exclusively breast-fed, compared with 3% of the low-birth-weight infants fed breast milk (p less than 0.001). The incidence rates of lactation over time were similar in the control and low-birth-weight groups (51% v. 44% at 1 month, 29% v. 13% at 3 months, 13% v. 4% at 6 months and 4% v. 2% at 12 months). The mean duration of lactation was 3.2 months for the control group and 2.5 months for the low-birth-weight group. In the long term 37% of the low-birth-weight infants fed breast milk failed to breast-feed, compared with 2% of the control infants, and only 31% were exclusively breast-fed, compared with 85% of the control infants (p less than 0.001). However, the degree of satisfaction with the lactation experience was similar in the two groups. We conclude that mothers of low-birth-weight infants have good potential for lactation.     

Microsomal dexamethasone binding sites identified by affinity labelling

Binding studies with [3H]dexamethasone identified a class of binding sites on male rat liver microsomes. The binding sites were glucocorticoid-dependent and specific for glucocorticoids and progestins. Scatchard binding parameters, competition studies with triamcinolone acetonide, a synthetic glucocorticoid which competes well for the glucocorticoid receptor, and immunoblotting with an antiglucocorticoid receptor antibody indicated that these sites are distinct from the cytosolic glucocorticoid receptor. Affinity labelling experiments with [3H]dexamethasone 21-mesylate revealed two specifically labelled peptides, one at approx. 66 kDa and a doublet at 45 kDa. The 66 kDa peptide had been previously identified in serum and may be present as a result of serum contamination of the microsomal preparation. The 45 kDa doublet, on the other hand, had been shown to be absent from rat serum. The characteristics of the 45 kDa peptide(s) were identical to those of the dexamethasone binding site identified in the binding studies. [3H]Dexamethasone binding characteristics and affinity labelling of microsomal subfractions, separated by isopycnic centrifugation, showed that the binding sites are located in the endoplasmic reticulum. The identification and role of the 45 kDa peptide doublet remain to be determined.