Effects of 60 Hz electric and magnetic fields on maturation of the rat neopallium

This study was undertaken to determine the effects of extremely low frequency (ELF; 60 Hz) electromagnetic (EM) fields on somatic growth and cortical development, as well as biochemical and morphological maturation, of the rat neopallium. On the fifth day of pregnancy, female rats were put in pairs into plastic cages that were housed in a specially constructed apparatus for irradiation under three separate sets of combination and intensity: 1) 1 kV/m and 10 gauss; 2) 100 kV/m and 1 gauss; and 3) 100 kV/m and 10 gauss. The dams were exposed for 23 h daily, from days 5 through 19 postconception after which they were returned to cages outside the exposure apparatus until they littered. The neonates were culled to eight pups per litter. At 0 (birth), 5, 12, and 19 days postnatally, they were killed for biochemical and morphological studies. Another group of pregnant rats was sham-exposed in an identical apparatus, which was not energized, and the pups were used as controls. The irradiated rats exhibited no physical abnormalities, nor did they show brain deformities such as swelling or herniation following exposure to ELF-EM fields. There was no difference in somatic growth between control and exposed rats, but a small reduction in cortical weight was observed in rats exposed at 1 kV/m and 10 gauss, and 100 kV/m and 1 gauss, respectively. Biochemical measurements of DNA. RNA, protein, and cerebroside concentrations indicated that among the three separate exposures, only the neopallium of rats exposed at 1 kV/m and 10 gauss showed a small reduction in DNA level, as well as small reductions in RNA and protein levels. No changes were noticed in cerebroside levels in any exposed animals, and there were no differences in protein/DNA and cerebroside/DNA ratios between control and exposed rats. Morphological observations did not reveal any detectable alterations in the irradiated rats. These results indicate that exposure to ELF-EM fields caused minimal or no changes in somatic growth and cerebral development of the rat. © 1993 Wiley-Liss, Inc.     

Mucous glycoproteins of teleostean fish: a comparative histochemical study

Synopsis To examine the hypothesis that the histochemical characteristics of teleostean mucus reflect functional characteristics, mucous cells were studied in four related and behaviourally similar species of fish (Family Belontidae). Histochemical characteristics were determined with Alcian Blue at both pH 2.6 and pH 1.0 followed by the periodic acid-Schiff technique. It was found that the four species differed in glycoprotein type as well as in number of mucus-containing cells. The differences are ciscussed in regard to functional characteristics and environmental influence.     

Prolactin-induced stimulation of H(3)-proline incorporation into the basement lamella of tadpole skin: light and electron microscope study

Radioautographic studies revealed that prolactin markedly stimulates the incorporation of H(3)-proline into the basement lamella of the tail fin of frog tadpole. Radioactivity in fibroblasts reached a peak at 3 hours. Thereafter, the number of silver grains in fibroblasts was reduced with concomitant increase in the basement lamella. Fibroblasts of the prolactin animals also showed extensively developed rough endoplasmic reticulum and Golgi elements. Epidermis of control animals was labelled as in the prolactin animals, although the basement lamella was sparsely labelled. Fibroblasts, not the epidermis, seem to secrete collagen into the basement lamella.     

Effects of 60 Hz electric and magnetic fields on the development of the rat cerebellum

The effects of extremely low frequency (ELF) electromagnetic (EM) fields on the maturation of the rat cerebellum were studied. Newborn rats were exposed to 60 Hz electric and magnetic fields under three different combinations in a specially constructed apparatus. The pups were irradiated for 7–8 h daily, with a 30-min interruption for nursing. Pups were kept with their mothers for the remainder of the time. After approximately 1, 2, or 3 weeks of exposure, the pups were killed. Control pups were sham exposed. The somatic growth of the irradiated rats did not show any significant difference from shamexposed controls. At 1 kV/m and 10 gauss exposure, there was a small but statistically significant decrease in cerebellar mass. In rats exposed at 1 kV/m and 10 gauss, DNA and RNA levels were significantly higher than those in shara-exposed controls at 6 and 13 days of age, but at 20 days, these two biochemical constituents were similar in both groups of rats. The ELF-EM treatment had no effect on protein and cerebroside concentrations. In terms of age effects. DNA and RNA exhibited increases from 6 to 13 days of age, and declined from 13 to 20 days. Protein and cerebroside levels exhibited increases during the 6–20 day periods. In rats exposed at 100 kV/m and 1 gauss, the DNA levels were initially less than those of sham-exposed controls at 8 days of age, reached approximately the same levels at 14 days, and then were higher than those of controls at 22 days. There was. therefore, a significant ELF-EM effect as well as a significant interaction between age and ELF-EM exposure. In terms of age effects, DNA levels for both control and exposed animals increased from 8 to 14 days. From 14 to 22 days, DNA levels of exposed rats continued to increase while those of the controls decreased. This age effect was significant. RNA levels in both groups of animals showed increases from 8 to 14 days of age, but the increase was less for the irradiated animals than for the controls. From days 14 to 22. RNA levels for both groups showed a reduction, but the decrease was greater in the irradiated than in control rats. ELF-EM treatment significantly reduced protein levels at 8 days of age. but at 14 to 22 days, protein levels of exposed rats were higher than those of controls. The cerebroside levels were not affected by exposure treatments but increased with the age of the animals. Exposure to 100 kV/m and 10 gauss did not exert any effect on the concentrations of DNA, RNA, protein, and cerebroside at all three time points examined. Both DNA and RNA exhibited increases with age from 6 to 13 days, and leveled off from 13 to 20 days. Protein and cerebroside levels also showed corresponding increases with the age of the animals. Morphological observations revealed no detectable changes in the irradiated animals in any experimental group. Thus, only biochemical studies indicate that exposure at certain ELF-EM field combinations induces alterations in cerebellar maturation. These changes were clearly detectable in the early postnatal period but gradually diminished with time. ©1993 Wiley-Liss, Inc.     

Ultrastructural studies on the ventricular surface of the frog cerebellum

Summary Ultrastructural studies of the ventricular surface of the frog cerebellum showed regional differences. In the midline region of the adult cerebellum was found a band of profusely ciliated squamous ependymal cells. In the rest of the cerebellum the ependymal cells were columnar and each had a single cilium. In the cerebellum of the premetamorphic tadpole, the squamous ependymal cells of the midline region also were monociliated. During metamorphosis they gradually became multiciliated. Additionally, supraependymal cells and synaptic elements were present on the ventricular surface of the cerebellum of adult frogs as well as in late metamorphic tadpoles. In contrast, supraependymal cells were rarely observed in premetamorphic tadpoles, and it was concluded that the supraependymal system develops during metamorphosis. It is postulated that the band of cilia may be associated with the circulation of cerebrospinal fluid, and supraependymal synaptic elements function in neuroendocrine regulation.     

Parents’ and Professionals’ Perceptions on Causes and Treatment Options for Autism Spectrum Disorders (ASD) in a Multicultural Context on the Kenyan Coast

Objective

To explore parents’ and professionals’ perceived causes and treatment of Autism Spectrum Disorders (ASD) on the Kenyan Coast.

Methods

In-depth interviews and focus group discussions using guiding questions were utilized in data collection. One hundred and three participants, who included parents of children with ASD, special needs teachers, clinicians, and social workers from diverse cultural background, participated in this study. The interviews and focus groups were recorded, transcribed verbatim and then translated to English. Themes were generated using content analysis.

Results

Preternatural causes were mentioned and included evil spirits, witchcraft, and curses. Biomedical causes comprised infections, drug abuse, birth complications, malnutrition, and genetic related problems. Treatment varied from traditional and spiritual healing to modern treatment in health facilities, and included consultations with traditional healers, offering prayers to God, and visits to hospitals.

Conclusions

The results suggest that regardless of cultural backgrounds, people on the Kenyan Coast have similar views on perceived causes and treatment of ASD. These findings provide valuable conceptual understanding for professionals when planning and implementing community based rehabilitation interventions targeting children with ASD within a local context.     

Socio-Cultural Determinants of Health-Seeking Behaviour on the Kenyan Coast: A Qualitative Study

Background

Severe childhood illnesses present a major public health challenge for Africa, which is aggravated by a suboptimal response to the child''s health problems with reference to the health-seeking behaviour of the parents or guardians. We examined the health-seeking behaviour of parents at the Kenyan coast because understanding impediments to optimal health-seeking behaviour could greatly contribute to reducing the impact of severe illness on children''s growth and development.

Methods and Results

Health-seeking behaviour, and the factors influencing this behaviour, were examined in two traditional communities. We held in-depth interviews with 53 mothers, fathers and caregivers from two rural clinics at the Kenyan Coast. Biomedical medicine (from health facilities and purchased over the counter) was found to be the most popular first point of treatment. However, traditional healing still plays a salient role in the health care within these two communities. Traditional healers were consulted for various reasons: a) attribution of causation of ill-health to supernatural sources, b) chronic illness (inability of modern medicine to cure the problem) and c) as prevention against possible ill-health. In developing an explanatory model of decision-making, we observed that this was a complex process involving consultation at various levels, with elders, but also between both parents, depending on the perceived nature and chronicity of the illness. However, it was reported that fathers were the ultimate decision makers in relation to decisions concerning where the child would be taken for treatment.

Conclusions

Health systems need to see traditional healing as a complementary system in order to ensure adequate access to health care. Importantly, fathers also need to be addressed in intervention and education programs.     

In vitro activity of tigecycline and comparators against carbapenem-susceptible and resistant Acinetobacter baumannii clinical isolates in Italy

Background

Effective neutralization of active agents is essential to obtain valid efficacy results, especially when non-volatile active agents like chlorhexidine digluconate (CHG) are tested. The aim of this study was to determine an effective and non-toxic neutralizing mixture for a propan-1-ol solution containing 2% CHG.

Methods

Experiments were carried out according to ASTM E 1054-02. The neutralization capacity was tested separately with five challenge microorganisms in suspension, and with a rayon swab carrier. Either 0.5 mL of the antiseptic solution (suspension test) or a saturated swab with the antiseptic solution (carrier test) was added to tryptic soy broth containing neutralizing agents. After the samples were mixed, aliquots were spread immediately and after 3 h of storage at 2 – 8°C onto tryptic soy agar containing a neutralizing mixture.

Results

The neutralizer was, however, not consistently effective in the suspension test. Immediate spread yielded a valid neutralization with Staphylococcus aureus, Staphylococcus epidermidis and Corynebacterium jeikeium but not with Micrococcus luteus (p < 0.001) and Candida albicans (p < 0.001). A 3-h storage period of the neutralized active agents in suspension resulted in significant carry-over activity of CHG in addition against Staphylococcus epidermidis (p < 0.001) and Corynebacterium jeikeium (p = 0.044). In the carrier test, the neutralizing mixture was found to be effective and non toxic to all challenge microorganisms when spread immediately. However, after 3 h storage of the neutralized active agents significant carry-over activity of CHG against Micrococcus luteus (p = 0.004; Tukey HSD) was observed.

Conclusion

Without effective neutralization in the sampling fluid, non-volatile active ingredients will continue to reduce the number of surviving microorganisms after antiseptic treatment even if the sampling fluid is kept cold straight after testing. This can result in false-positive antiseptic efficacy data. Attention should be paid during the neutralization validation process to the amount of antiseptic solution, the storage time and to the choice of appropriate and sensitive microorganisms.     

Prevalence of Human Papillomavirus Genotypes among African Women with Normal Cervical Cytology and Neoplasia: A Systematic Review and Meta-Analysis

Background

Several meta-analyses confirmed the five most prevalent human papillomavirus (HPV) strains in women with and without cervical neoplastic diseases are HPV16, 18, 31, 52, and 58. HPV16/18 are the predominant oncogenic genotypes, causing approximately 70% of global cervical cancer cases. The vast majority of the women studied in previous analyses were from Europe, North America, Asia, and most recently Latin America and the Caribbean. Despite the high burden of cervical cancer morbidity and mortality in Africa, a robust meta-analysis of HPV genotype prevalence and distribution in African women is lacking.

Methods and Findings

We systematically searched 14 major databases from inception to August 2013 without language restriction, following the Meta-Analysis of Observational Studies in Epidemiology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-one studies from 23 African countries were identified after screening 1162 citations and data abstracted and study quality appraised from 195 articles. HPV type-specific prevalence and distribution was estimated from 17,273 cases of women with normal cervical cytology; 1019 women with atypical squamous cells of undetermined significance (ASCUS); 1444 women with low-grade squamous intraepithelial lesion (LSIL); 1571 women with high-grade squamous intraepithelial lesion (HSIL); and 4,067 cases of invasive cervical carcinoma (ICC). Overall prevalence of HPV16/18 were 4.4% and 2.8% of women with normal cytology, 12.0% and 4.4% with ASCUS, 14.5% and 10.0% with LSIL, 31.2% and 13.9% with HSIL, and 49.7% and 18.0% with ICC, respectively. Study limitations include the lack of adequate data from Middle and Northern African regions, and variations in the HPV type-specific sensitivity of different genotyping protocols.

Conclusions

To our knowledge, this study is the most comprehensive assessment of the overall prevalence and distribution of HPV genotypes in African women with and without different cervical neoplasias. We have established that HPV16/18 account for 67.7% of ICC cases among African women. Based on our findings, we highly recommend the administration of existing prophylactic vaccines to younger women not infected with HPV16/18 and an increase in HPV screening efforts for high-risk genotypes to prevent cervical cancer. Review registration: International Prospective Register of Systematic Reviews CRD42013006558.