Hyaluronic acid inhibits fetal platelet function: implications in scarless healing

Platelets are important for the initiation of inflammation in adults, but the role of fetal platelets in fetal wound healing is unclear because fetal dermal wounds heal with a minimal inflammatory response and lack of excessive scarring. Because fetal tissue is abundant in glycosaminoglycans (GAGs), predominantly hyaluronic acid (HA), this study was designed to test the hypothesis that HA inhibits the reactivity of platelets and thus contributes to the minimal scarring characteristic of fetal tissue repair. Platelets were isolated from 10 fetal pigs at day 80 of gestation (term, 115 days) and exposed to 0.5 mg/mL of arachidonic acid, an agent shown in prior studies to evoke maximal aggregation and degranulation of fetal platelets. The ability of HA at 0.1 and 0.5 mg/mL to inhibit this response was determined. The presence of HA resulted in a dose-dependent reduction in platelet aggregation at 180 seconds (control, 99.7 +/- 0.3%; HA [0.1 mg/mL] 91.7 +/- 3.8%; and HA [0.5 mg/mL] 48.5 +/- 9.0%; P < .005 v control). The onset of aggregation was also significantly delayed by 0.5 mg/mL of HA (13.5 +/- 2.5 seconds) compared to control (2.9 +/- 0.7 seconds), P < .05. No significant diminution of platelet aggregation could be achieved by the addition of other GAGs at similar concentrations. HA also significantly impaired the release of platelet-derived growth factor (PDGF)-AB from fetal platelets. The authors conclude that HA, the predominant GAG in fetal dermal matrix, inhibits platelet aggregation and cytokine release. This inhibition of platelet aggregation and resultant inflammatory response may explain, in part, the minimal inflammation and scarless healing characteristic of fetal dermal repair.     

Chlamydial infection in inducible nitric oxide synthase knockout mice

Type 1 CD4+-T-cell-mediated immunity is crucial for the resolution of chlamydial infection of the murine female genital tract. Previous studies demonstrating a correlation between CD4+-T-cell-mediated inhibition of chlamydial growth and gamma interferon (IFN-gamma)-mediated induction of nitric oxide synthase suggested a potential role for the nitric oxide (NO) effector pathway in the clearance of Chlamydia from genital epithelial cells by the immune system. To clarify the role of this pathway, the growth levels of Chlamydia trachomatis organisms in normal (iNOS+/+) mice and in genetically engineered mice lacking the inducible nitric oxide synthase (iNOS) gene (iNOS-/- mice) were compared. There was no significant difference in the course of genital chlamydial infections in iNOS+/+ and iNOS-/- mice as determined by recovery of Chlamydia organisms shed from genital epithelial cells. Dissemination of Chlamydia to the spleen and lungs occurred to a greater extent in iNOS-/- than in iNOS+/+ mice, which correlated with a marginal increase in the susceptibility of macrophages from iNOS-/- mice to chlamydial infection in vitro. However, infections were rapidly cleared from all affected tissues, with no clinical signs of disease. The finding of minimal dissemination in iNOS-/- mice suggested that activation of the iNOS effector pathway was not the primary target of IFN-gamma during CD4+-T-cell-mediated control of chlamydial growth in macrophages because previous reports demonstrated extensive and often fatal dissemination of Chlamydia in mice lacking IFN-gamma. In summary, these results indicate that the iNOS effector pathway is not required for elimination of Chlamydia from epithelial cells lining the female genital tract of mice although it may contribute to the control of dissemination of C. trachomatis by infected macrophages.     

Facial and ear dimensions in term Nigerian neonates

A study of selected facial and ear dimensions in 200 term and appropriate-for-gestational age neonates delivered at the University College Hospital, Ibadan, Nigeria, was carried out with the aim of describing their normal range of variation and providing reference values for clinical use. The features studied included inner canthal distance, outer canthal distance, palpebral fissure length, nasolabial distance, oral intercommissural length, total ear length and ear length above the eyeline. The inner canthal distance ranged from 1.6 to 2.5 cm with a mean of 2.1 (SD 0.2) cm while the outer canthal distance ranged from 5.2 to 7.2 cm with a mean of 6.1 (SD 0.4) cm. The oral intercommissural length ranged from 2.5 to 4.0 cm with a mean of 3.1 (0.3) cm and the total ear length ranged from 2.4 to 4.0 cm with a mean of 3.2 (SD 0.3) cm. Three per cent of the neonates had the whole ear located completely below the eye line. No significant sex differences in the mean values of any of the dimensions studied were found. The findings of the study are consistent with those of other workers who have documented shorter ears in the Negro neonate compared to his Caucasian counterpart. It is suggested that local values derived from well-defined populations be used as reference in the evaluation of the child with dysmorphic features in order to avoid errors of classification due to racial variations in the range of normal.     

Soluble and insoluble fiber contents of some Cameroonian foodstuffs

As a result of the lack of reliable data on the fiber content of African foodstuffs, a study to determine the dietary fiber contents (soluble, insoluble and total) on a dry weight basis of a selected variety of major Cameroonian foods was conducted. The influence of processing and preparation methods on the fiber content was also assessed. Vegetables were found to be the richest source of total dietary fiber (57%), followed by legumes and seeds (30%) and fruits (16.5%). Okro (Hibiscus esculenta), plantain (Musa paradisiaca) and beans (Phaseolus spp) showed varietal differences in their soluble and insoluble fiber content, while methods of processing and preparation significantly influenced the fiber content of cassava (Manihot esculenta), corn (Zea mays) and beans.     

The effects of ivermectin on onchocercal skin disease and severe itching: results of a multicentre trial

OBJECTIVE: To determine the effects of ivermectin in annual, 3-monthly and 6-monthly doses on onchocercal skin p6isease (OSD) and severe itching. METHOD: A multicentre, double-blind placebo controlled trial was conducted among 4072 residents of rural communities in Ghana, Nigeria and Uganda. Baseline clinical examination categorized reactive skin lesions as acute papular onchodermatitis, chronic papular onchodermatitis and lichenified onchodermatitis. Presence and severity of itching was determined by open-ended and probing questions. Clinical examination and interview took place at baseline and each of 5 subsequent 3-monthly follow-up visits. RESULTS: While prevalence and severity of reactive lesions decreased for all 4 arms, those receiving ivermectin maintained a greater decrease in prevalence and severity over time. The difference between ivermectin and placebo groups was significant for prevalence at 9 months and for severity at 3 months. Differences between placebo and ivermectin groups were much more pronounced for itching. From 6 months onward, the prevalence of severe itching was reduced by 40-50% among those receiving ivermectin compared to the trend in the placebo group. CONCLUSION: This is an important effect on disease burden as severe itching is for the affected people the most troubling complication of onchocerciasis. The difference among regimens was not significant, and the recommended regimen of annual treatment for the control of ocular onchocerciasis appears also the most appropriate for onchocerciasis control in areas where the skin manifestations predominate. The final determination of the effect on skin lesions requires a longer period of study.     

The modulating action of serotonin on single calcium channels in the neurons of the snail Helix pomatia

The influence of a neurotransmitter serotonin (5-hydroxytriptamine, 5-HT) on single Ca2+ channel activity was studied on unidentified neurons of the snail Helix pomatia. Our findings showed that 5-HT influences the channel molecule in indirect manner, as it appeared effective at its application by adding to the bath solution, that had no contact with the tested membrane fragment. This finding excludes the possibility of direct binding of 5-HT to the channel molecule and shows that the effect is really mediated through a cytoplasmic messenger, cAMP-dependent cascade of phosphorylation. Also our investigations shows, that only one type of Ca2+ channel with the unitary conductance of 5 pS was identified in this kind of neurons.     

Energy intakes, anthropometry and body composition of Nigerian adolescent girls: a case study of an institutionalized secondary school in Ibadan

Twenty-two apparently healthy Nigerian adolescent girls aged 11-17 years residing in a hostel, were studied over five consecutive days in order to assess their energy intake (EI), energy cost of specific activities and body composition (BC). The mean characteristics of the group were: height 1.58 (SD 0.1, range 1.42-1.68) m, body weight 49.1 (SD 7.9, range 34.0-61.0) kg and BMI 19.5 (SD 2.0, range 16.0-23.0) kg/m2. The food intake of each subject was assessed by direct weighing and its energy value was determined by means of a ballistic bomb calorimeter. BMR values were calculated according to Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) (1985) equations. Percentage body fat (BF%) values were derived from three skinfold thickness measurements, using population-specific equations. The adolescents' mean daily EI was found to be 6510 (SD 855) kJ/d (138.3 (SD 27.8) kJ/kg body weight per d) which is lower than the FAO/WHO/UNU (1985) calculated energy requirement of 8800 kJ/d for adolescent girls aged 12-14 years. The contributions of specific nutrients and individual meals to the total EI were: carbohydrate, protein and fat, 59.2, 12.5 and 28.3% of energy respectively and breakfast, lunch and supper, 21.5, 41.0 and 37.4% respectively. However, the mean BMR was 5627 kJ/d, which is comparable with that given by FAO/WHO/UNU (1985) for adolescent girls aged 13-14 years. The mean BF% was found to be 21.7. The comparatively low EI of the participants in the present study may be indicative of energy deficiency in their meals. This assumption is also reflected in their BC values. Nevertheless, further studies of this kind on adolescents in Nigeria are needed to confirm these observations.     

The standard biphasic-contrast gastric series

Biphasic gastric studies combining the advantages of both single- (positive) and double-contrast techniques performed under hypotony can now be accomplished as a routine procedure. In a series of 5,000 studies, the standardized method averaged only 15 minutes per patient.     

Dermatofibrosarcoma protruberans: analysis of eight cases in an African population

Eight cases of dermatofibrosarcoma protruberans seen in the University College Hospital, Ibadan, Nigeria between 1960 and 1972 are reviewed. The condition is rare in this population and affects young adults of both sexes. All were treated by wide excision and skin grafting with no recurrence at follow-up. The apparently low incidence being reported may be due in part to the inconsistent histological pattern of the lesion. Clinicians are urged to be more aware of this condition when a cutaneous, nodular or multiobulated tumor is encountered.