Long term effects of maternal protein restriction on postnatal lung alveoli development of rat offspring.

Poor nutrition of women during pregnancy causes reduction in foetal growth and can adversely affect the development of the foetal lungs. The purpose of the present study was to assess the effects of maternal protein restriction on the postnatal lung development in neonatal period, and on lung structure in adult rat offspring. Female virgin Sprague-Dawley albino rats (more than 200 g) were used. One male rat was introduced into a cage with one female for matting. Once the pregnancy was confirmed, pregnant rats were divided into two main groups; each consists of 6 female as follow: 1 - normally nourished group; 2 - protein deficient group. After delivery, offspring were subdivided into three groups: 1 day after delivery, 2 weeks and 2 months postnatal. Rat body and lung weight were recorded and ratio of lung weight to body weight was assessed. Total plasma protein and serum albumin were assessed for all groups. Lung tissue stained with H&E for histological and morphometric analysis. Immunohistochemistry was performed to evaluate the number of cells positive for pulmonary surfactant protein A. Our results showed that protein restriction interfere with neonatal and postnatal lung development resulting in morphological and morphometric changes of normal lung development. We concluded that protein deficiency lead to developmental retardation of lung.

Acral lesions of vitiligo: why are they resistant to photochemotherapy?

BACKGROUND: Acral lesions of vitiligo are usually resistant to conventional lines of treatment as well as surgical interventions. OBJECTIVE: To clarify causes underlying resistance of acral lesions to pigmentation in vitiligo by studying some of the factors associated with mechanisms of repigmentation following photochemotherapy. METHODS: The study included twenty patients with active vitiligo. Skin biopsies were taken from lesional and perilesional skin of areas expected to respond (trunk and proximal limb) and skin of acral areas, before and after PUVA therapy. Sections were stained with H and E, Melan-A, MHCII, CD1a, SCF and c-kit protein. RESULTS: Before treatment acral areas showed significantly lower hair follicle density, melanocyte density, Langerhans cell (LC) density, epidermal MHCII expression, lesional SCF expression and perilesional c-kit expression. Following treatment with PUVA in both non-responsive acral and repigmenting non-acral lesions identical immunohistochemical changes in the form of significant decrease in LC density, epidermal MHC-II and SCF expression were observed. CONCLUSION: The surprisingly similar histochemical changes in response to PUVA in acral and non-acral lesions did not manifest with clinical repigmentation except in non-acral ones. Factors such as inherent lower melanocyte density, lower melanocyte stem cell reservoirs and/or lower baseline epidermal stem cell factor may be considered as possible play makers in this respect.

Extended effect of Bacillus thuringiensis H-14 on Culex pipiens adults surviving larval treatment.

Three Bacillus thuringiensis H-14 preparations (a laboratory prepared and two commercial formulations namely, Tecknar and Vectobac) were assayed against third instar Culex pipiens larvae in order to trace their toxic activity on larval treatment. The LC50 values were 0.002, 0.02 and 0.04 ppm. respectively. The laboratory strain was tested on the development of Culex pipiens. Larval mortality, pupation, adult emergence and sex ratio showed significant differences as compared to the non-treated group. Toxic action on the treated larvae with laboratory strain of B. thuringiensis H-14 revealed drastic effect on larval mid-gut epithelium and resulted in extended pathological activity in adults, which survived larval treatments. Nervous and reproductive systems were found to be the most damaged systems in female adults.

Potential for Culex pipiens to develop resistance against Bacillus sphaericus toxins.

Susceptibility of field Culex pipiens populations to Bacillus sphaericus and the possibility of resistance development in the selected laboratory colony were investigated. 180 populations collected from Giza and Qualyobia over one year show no marked variation at LC50 and LC90 values. Larvae of laboratory colony of Cx pipiens were subjected to selection pressure with a preparation of Bacillus sphaericus strain 2362 at LC80 values for 20 successive generations. The selected laboratory colony began developing resistance at F10 (RR = 1.69) when compared with its unselected counterpart. The magnitude of resistance increased gradually and reached 33 fold by F20. The unselected colony reared without any exposure to the B. sphaericus toxin, did not show any marked change in their susceptibility to this microbial agent.