Histology and Histochemistry of the Stomach Epithelium of Pachycondyla (= Neoponera) villosa (Formicidae: Ponerinae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Histology, histochemistry and stereology of the adipose fin of Prochilodus lineatus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structure of the posthepatic septum and its influence on visceral topology in the tegu lizard, Tupinambis merianae (Teiidae : Reptilia)

The posthepatic septum (PHS) divides the body cavity of Tupinambis merianae into two parts: the cranial one containing the lungs and liver and the caudal one containing the remaining viscera. The PHS is composed of layers of collagenous fibers and bundles of smooth muscle, neither of which show systematic orientation, as well as isolated blood vessels, lymphatic vessels, and nerves. Striated muscle of the abdominal wall does not invade the PHS. The contractions of the smooth muscles may stabilize the pleurohepatic cavity under conditions of elevated aerobic needs rather than supporting breathing on a breath-by-breath basis. Surgical removal of the PHS changes the anatomical arrangement of the viscera significantly, with stomach and intestine invading the former pleurohepatic cavity and reducing the space for the lungs, Thus, the PHS is essential to maintain the visceral topography in Tupitionibis. J. Morphol. 258:151-157, 2003. (C) 2003 Wiley-Liss. Inc.

Lactose load enhances the growth of the small intestine in rats

The present study was undertaken to elucidate the controversial issue regarding the small intestinal structural adaptation, in lactose fed rats. Three study groups were used. One experimental fed 60% lactose and two controls in which the lactose was substituted for similar amount of starch. One of them was fed ad libitum and another a limited amount of food to match the body weight of lactose group. The weight, length of the intestine and intestinal mucosal DNA and protein were determined at days 2, 5, 10 and 30 of the experiment. As compared to starch fed ad libitum controls, animals fed 60% lactose diet ate similar amount of food, grew at a slower rate and weighed 16,7% less at the end of the experiment. In contrast to retarded gain in body weight, small intestinal mucosa of these animals contained more DNA (22,5%) and protein (37,5%) than that of controls. These changes were paralleled by increase in length (17%) and weight of the intestine (24,2%). Therefore, the results of the present study confirmed the findings that the small intestine increases in size in response to lactose feeding and that this occurs in the abscense of hyperphagia. It was further demonstrated that this increase was due both to mucosal cell hyperplasia and hypertrophy.

Walker 256 tumour growth causes marked changes of glutamine metabolism in rat small intestine

The effect of Walker 256 tumour growth on the metabolism of glucose and glutamine in the small intestine of rats was examined. Walker 256 tumour has been extensively used as an experimental model to induce cancer cachexia in rats. Walker 256 tumour growth decreased body weight and small intestine weight and length. The activities of glucose-6-phosphate dehydrogenase and phosphate-dependent glutaminase were reduced in the proximal, median and distal portions of the intestine. Glutamine oxidation was reduced in the proximal portion only. The decrease in glutaminase activity was not due to a low synthesis of the protein as indicated by Western blotting analysis. Hexokinase and citrate synthase activities were not changed by the tumour. These findings led us to postulate that tumour growth impairs glutamine metabolism of small intestine but the mechanism involved remains to be elucidated. Copyright (C) 2001 John Wiley Sons, Ltd.

Histology and morphometry of the testes of adult domestic cats (Felis catus)

Testicles of 30 mongrel cats were analyzed histologically and morphometrically, divided into three groups: G1 (1-2 years old), G2 (over 2 and up to 4 years old) and G3 (over 4 and up to 6 years old). After orchiectomy and histopathology, the morphometric parameters studied were: thickness of the tunica albuginea (72 mu m) and seminiferous epithelium (77.19 mu m), perimeter (53.81; 90.57 mu m), (54.80; 101.07 mu m); area (174.23; 494.55 mu m(2)), (176.68; 629.70 mu m(2)); maximum diameter (14.94; 28.02 mu m), (14.76; 31.66 mu m); minimum diameter (13.25; 21.92 mu m), (13.30; 24.52 mu m); and shape factor (index for regularity of the format) (1.36; 1.36), (1.39; 1.35) of the nucleus and cytoplasm of spermatogonia and Leydig cells, respectively. The results can be used for comparative studies and contribute knowledge concerning the height of the seminiferous epithelium, thickness of the tunica albuginea and size of spermatogonia and Leydig cells.

Detection of T lymphocytes in intestine of broiler chicks treated with Lactobacillus spp. and challenged with Salmonella enterica serovar enteritidis

The expression of immune response in the form of leukocytic infiltrate by CD3+, CD4+, and CD8+ cells in the epithelium and in the intestinal lamina propria of chicks was studied in the present work by means of immunohistochemical reaction. The chicks were treated with Lactobacillus spp. or cecal microflora (CM) and experimentally challenged or not with Salmonella enterica serovar Enteritidis. The 320 birds utilized were divided into 4 groups containing 80 chicks each and submitted to treatments with Lactobacillus reuteri, Lactobacillus salivarius, Lactobacillus acidophilus, and CM. Each group was subdivided into 4 subgroups of 20 birds each and classified into a subgroup that did not receive treatment (negative control), subgroup treated, subgroup treated and challenged with Salmonella Enteritidis, and subgroup only challenged with Salmonella Enteritidis (positive control). The results obtained show that the treatment with L. reuteri, L. salivarius, L. acidophilus, or CM and challenged or not with Salmonella Enteritidis determine immune response in the form of leukocytic infiltrate by CD3+ and CD8+ lymphocytes followed by CD4+ in the epithelium and in the lamina propria of the duodenum, jejunum, and cecum of chicks up to 12 d of age. The quantity of CD3+ lymphocytes was significantly higher (P < 0.05) in the intestine of chicks treated with L. acidophilus or CM and challenged or not with Salmonella Enteritidis; however, the higher quantity of CD8+ lymphocytes was in the intestine of chicks treated with CM and challenged with Salmonella Enteritidis. The duodenum was the segment in which the immune response by T cells (CD3+, CD4+, and CD8+) was stimulated with the greatest intensity, followed by, respectively, the jejunum and cecum. The quantity of CD3+ lymphocytes present in the duodenum, jejunum, and cecum increases with the age of chicks, independent of the stimulus determined by treatments or challenge.

The effect of Ketoconazole on experimental paracoccidioidomycosis in the Syrian hamster: immunological and histopathological study

The effect of Ketoconazole (KTZ) on the hamster experimental intratesticular paracoccidioidomycosis was studied employing different treatment schedules. KTZ long course treatment beginning at an early stage of the infection was effective in preventing fungal proliferation, dissemination to lymph nodes, spleen and kidneys, and in maintaining low levels of humoral and cellular specific immune responses. KTZ short course treatment starting at an advanced stage of disease resulted in a more severe histopathological picture without significant changes in the immunological profile. The drug prolonged the life span of hamsters infected with Paracoccidioides brasiliensis, but did not prevent mortality. Toxic necrosis of the bone marrow occurred in normal animals receiving 120 mg/kg/day of KTZ but with lower doses no morphologic alterations were observed in heart, lungs, kidneys, adrenals, spleen, liver, intestine or bone marrow. © 1984 Dr W. Junk Publishers.

Morphometric study of the small intestinal mucosa in young, adult, and old rats submitted to protein deficiency and rehabilitation

Linear and stereological morphometric methods were applied to the jejunal and ileal mucosa of young, adult, and old male Wistar rats submitted to protein deficiency and rehabilitation. The animals were fed ad libitum a 2% casein diet during 42 days and then received a 20% casein diet for 30 days. Food intake, body weights, and plasma protein concentrations were recorded. In the young protein deficient rats values of mucosal height, surface area, and volume of the lamina propria were significantly lower than those of their age controls in both jejunum and ileum. In adults the differences were less marked and in the old rats all parameters were found to be unaltered by the protein deficient diet. The surface-to-volume ratio showed no significant differences between control and protein deficient in all three age groups, meaning that villus pattern did not change with protein deficiency. On rehabilitation, a striking difference between jejunum and ileum was observed in the young rats; all parameters returned to control levels in the jejunum, while they remained lower than those of their controls in the ileum.

Characterization of a monoclonal antibody recognizing mast cells

Immunohistochemical screening for monoclonal antibodies prepared by immunization of mice with a rat osteoblastic cell population led to identification of one antibody that reacted against a small population of cells present in the soft connective tissue compartment of 21 days fetal rat calvaria. The morphology of the cells and the immunohistochemical staining characteristics (a distinct intracellular granular pattern) suggested that the antibody might be reacting specifically against mast cells. We used combined histochemistry and immunohistochemistry to further characterize this antibody, designated RCJ102. Cryosections containing calvaria bone, soft connective tissues and skin were prepared from the top of the head of 21 days fetal rats, and from adult rats cryosections of lung, muscle, adipose tissue and small intestine were prepared. Some sections were labelled by indirect immunofluorescence with RCJ102; corresponding sections were labelled histochemically with toluidine blue. There was a direct correspondence between mast cells identified histochemically and cells labelling with RCJ102 in all tissues except intestine, in which the mast cell detectable by histochemistry were not labelled by RCJ102. These results suggest that the RCJ102 antibody will be a valuable new reagent for further elucidation of the heterogeneity described between connective tissue and intestinal mucosal mast cells.

Performance and physiological parameters of broiler chickens subjected to fasting on the neonatal period

Broiler chicks aged 12 h after hatching were allotted according to a block design in a 7 x 2 factorial schedule of 14 treatments and four replications of 50 chicks each one. The main experimental factors were fasting for 0, 6, 12, 18, 24, 30, and 36 h after chick placement and sex. Independent of sex, fasting had a negative linear effect on weight and productivity of broilers at market age (42 d) without affecting feed conversion or mortality index. Groups subjected to 18 and 36 h of fasting after placement, corresponding to 30 and 48 h posthatching fasting, had lower biometrical values for small intestine (length, weight, and size; villus height; and crypt depth) than chicks fed immediately after placement. According to the Pearson test, BW of birds at 21 and 42 d were significantly correlated to BW at 7 d (r = 0.77) and 21 d (r = 0.45), respectively. Males performed better than females but had higher mortality rates. Fasting did not influence serum concentrations of corticosterone or sexual steroid hormones. Nevertheless, early signs of sexual dimorphism arose from the high estradiol (E2) concentration on female serum. Heterophil:lymphocyte ratio was not different among treatments, indicating that early fasting did not seem to be a stress factor 21 or 42 d after fasting. The results suggested a maximum fasting of 24 h after hatching in order to preserve broiler productivity at market age.

Comparative study of the histology, histochemistry and ultramorphology of the proventriculus in the cephalotini tribe (Hymenoptera: Formicidae)

The use of optical microscopy and scanning electron microscopy propitiated the comparative examination of the nature of the histology, histochemistry and ultramorphology of the proventriculus bulb of Cephalotes atratus, C. clypeatus and C. pusillus. This portion of the digestive tract possesses highly sclerotized cuticular projections which act in the selection of victuals. A layer of amorphous material with mucous characteristics is present over the cuticle projections. That layer seems to optimize the efficiency of the proventriculus in the selection of food for social function in the colony (trophallaxis). More details of the characteristics of this structure are described in this study.

Telomerase activity in the vaginal margins of radical hysterectomy in patients with carcinoma of the cervix: Correlation with histology and human papillomavirus

This study was undertaken to evaluate the telomerase activity both in the tumor and in the vaginal margins of radical hysterectomy in patients with squamous cell carcinoma (SCC) of the cervix. Thirty-three patients with SCC of the cervix (study group) and 13 patients with uterine myoma (control group) were prospectively studied. Tissue samples were taken from the tumor or cervix, anterior vaginal margin (AVM), and posterior vaginal margin (PVM). The specimens were analyzed by histopathology, by a telomerase PCR-TRAP-ELISA kit, and by polymerase chain reaction using human papillomavirus (HPV) DNA. The telomerase activity was significantly higher in the tumor than in the benign cervix (P < 0.001). There was no difference in telomerase activity in the AVM and PVM in patients with cervical carcinoma compared to the control group. Telomerase activity was associated with the presence of histologic malignancy in the PVM of patients submitted to radical hysterectomy (P = 0.03). This association was not observed with the presence of HPV in AVM or PVM in the study group. Telomerase activity is a marker of histologic malignancy in patients with SCC of the cervix. There was no association between the telomerase activity and the presence of HPV in vaginal margins of patients submitted to radical hysterectomy. © 2006, Copyright the Authors.

Surface area of the tip of the enterocytes in small intestine mucosa of broilers submitted to early feed restriction and supplemented with glutamine

A total of 640 one-day-old male Cobb chicks were used to evaluate the effects of early feed restriction and glutamine on villi density and tip surface of enterocytes in the small intestine of broilers. A two-factor factorial experimental design with glutamine and feed restriction as main factors was used. Treatments consisted of quantitative feed restriction at 30% of ad libitum intake from 7 to 14 days of age, and glutamine addition at 1% in the diet from 1 to 28 days of age. Sections of the small intestine (duodenum, jejunum, ileum) were collected at 14 and 21 days of age for analyses by scanning and transmission electron microscopy. Villi density decreased with age and increased in cranial-caudal direction. Glutamine increased villi density in the small intestine. Microvilli density and height decreased with age. Glutamine increased microvilli width. The jejunum was the segment with the largest surface area of the tip of the enterocytes, followed by the duodenum and the ileum. Feed restriction decreased the surface area of the tip of the enterocytes in the small intestine at 14 and at 21 days of age. Glutamine supplemented in the feed increased the surface area of the tip of the enterocytes of the jejunum and ileum at 21 days of age. © Asian Network for Scientific Information, 2007.

Microscopic, morphometric and ultrastructural analysis of anastomotic healing in the intestine of normal and diabetic rats

The purpose of this study was to investigate if experimental alloxanic diabetes could cause qualitative changes in intestinal anastomoses of the terminal ileum and distal colon in rats, as compared to controls. 192 male Wistar rats, weighing ± 300g were split into four experimental groups of 48 animals each, after 3 months of follow-up: a control group with ileum anastomoses (G1), a control group with colon anastomoses (G2), a diabetic group with ileum anastomoses (G3) and a diabetic group with colon anastomoses (G4). Animals were evaluated and sacrificed on days 4, 14, 21 and 30 after surgery, and fragments of the small and large intestine where the anastomoses were performed were removed. Samples from 6 animals from each sacrifice moment were submitted to ultrastructural analysis of the collagen fibers using a scanning electron microscope and samples from another 6 animals were submitted to histopathology and optical microscopy studies using picrosirius red-staining. Histopathological analysis of picrosirius red-stained anastomosis slides using an optical microscope at 40x magnification showed that the distribution of collagen fibers was disarranged and also revealed a delay in scar tissue retraction. The morphometric study revealed differences in the collagen filled area for the ileum anastomoses 14 days post surgery whereas, in the case of colon anastomoses, differences were observed at days 4 and 30 post surgery, with higher values in the diabetic animals. Ultrastructure analysis of the ileum and colon anastomoses using a scanning electron microscope revealed fewer wide collagen fibers, the presence of narrower fibers and a disarranged distribution of the collagen fibers. We conclude that diabetes caused qualitative changes in scar tissue as well as in the structural arrangement of collagen fibers, what could explain the reduced wound strength in the anastomosis of diabetic animals. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart.