Pregnancy-associated structural changes of the fallopian tube of rabbits with special reference to interstitial Cajal-like cells

The histological structure of the fallopian tube shows remarkable changes during pregnancy. Interstitial Cajal cell is known to play a key role in pacemaking motility in the gastrointestinal tract and the urinary tract. Its role in the motility of the fallopian tube is not fully explained. To describe the histological changes in the fallopian tube during early and late pregnancy, to shed light on the morphology of interstitial Cajal-like cells [ICLCs], and to localize their regional distribution in the fallopian tube in nonpregnant and pregnant rabbits. Thirty adult female rabbits were divided into three groups: group I [nonpregnant], group II [early pregnancy - day 4], and group III [late pregnancy - day 27]. The ampulla of the fallopian tube was excised and processed for histological, immunohistochemical, transmission, and scanning electron microscopy. In the nonpregnant group, it was found that the lining epithelium of the fallopian tube was composed of both ciliated and secretory cells. The ciliated cells were the major epithelial cell types; CD34-positive ICLCs were found maximally in the superficial zone of lamina propria, followed by musculosa, the deep portion of lamina propria, and least in serosa. The early pregnancy group showed a significant reduction in ciliated cells and an increase in secretory cells. In addition, there was a significant increase in the height of secretory cells and development of secretory organelles. There was a reduction in the number of CD34-positive ICLC in the superficial lamina propria compared with nonpregnant animals. The late pregnancy group showed an insignificant increase in ciliated cells and a decrease in secretory cells compared with group II. In addition, there was a decrease in the height of secretory cells and a reduction in their secretory organelles, but still more than that in group I. The structure of the fallopian tube showed histological changes during pregnancy. These changes represented a functional conditioning to the pregnancy state. ICLCs in the fallopian tube were prone to the same changes in their count and distribution

Histological, immunohistochemical, and morphometric study on the postnatal development of Peyer's patches in albino rat

Peyer's patches [PPs] are essential elements of the gut-associated lymphatic tissue that are involved in defense against pathogens that may be colonizing the gut and are also involved in oral food tolerance otherwise food allergy occurs. This research aimed to study the postnatal development of PPs in male albino rats. Fifty male albino rats were divided into five groups of 10 animals each. Group 1 [1 day old], group 2 [1 week old], group 3 [2 weeks old], group 4 [4 weeks old], and group 5 [8 weeks old]. The terminal part of the ileum was dissected out and processed for light and electron microscopic examinations. Paraffin sections were stained with hematoxylin and eosin, periodic acid-Schiff and immunohistochemical staining was carried out for detection of CD3 and CD20 [markers of T and B lymphocytes, respectively]. Quantitative morphometric study was conducted, and the results were statistically analyzed. Early during postnatal period, PPs appeared as small epithelial elevations overlying small aggregates of lymphocytes. The size of PPs and lymphocytic cell density increased gradually to reach maximum by adult age [group 5]. Most of the lymphocytes were of the T type early postnatally followed by increase in B lymphocytes during the following age groups. Germinal centers started to appear in group 4 and in the adult age group. The epithelium covering the surface of PPs showed reduced number of goblet cells, and M cells started to appear from the age of 2 weeks onward. Epithelium covering the PPs showed structural changes matching with functional specialization such as gradual reduction of goblet cells and appearance of M cells. In addition, an association was found between the times of onset of M cells and B-Iymphocytic follicles in PPs

Optimization of Extracellular Lipase Production by Penicillium chrysogenum Using Factorial Design

The effect of oxygen on lipase production by Penicillium chrysogenum was studied under two operating modes, controlled aeration rate tested and controlled agitation at dissolved oxygen concentration (DO) 1.00 vvm. Lipase production and cell dry weight were tested in a stirred batch fermenter 5 L. Improvement in oxygen transfer rate (OTR) either by aeration or agitation resulted in an increase in lipase production. Growth curves and lipase activities of P.chrysogenum were examined at agitation rates (200,400,600 rpm), aeration rates (2,4 vvm) at different fermentation periods (24,48,72,96,120 h). Response Surface Methodology (RSM) using Design Expert software was used to study the effect of aeration, agitation, and fermentation time on lipase activity and cell dry weight. These factors were analyzed using 21. 32 level factorial design. An optimal set of conditions that maximize lipase production: (2 vvm aeration; 600 rpm agitation after 72 h) was obtained. The maximum lipase activity obtained was 240 U/mL. Beside lipase activity, this paper also studies the optimal combination of the controllable factors (aeration; agitation and fermentation time) that will maximize the cell dry weight.