Thyroid hormone controls remodeling of the tadpole intestine during the climax of amphibian metamorphosis. In 8 days, the Xenopus laevis tadpole intestine shortens in length by 75%. Simultaneously, the longitudinal muscle fibers contract by about the same extent. The radial muscle fibers also shorten as the diameter narrows. Many radial fibers undergo programmed cell death. We conclude that mus...

Mouse submaxillary epithelium undergoes branching morphogenesis with increase in the curvature of its surface in vivo. Recombination experiments in vitro of the epithelium and mesenchyme between 13- and 14-day rudiments showed (1) that the 14-day mesenchyme more actively induced the epithelium to branch than the 13-day mesenchyme, (2) that the 14-day mesenchyme could produce clefts on smaller e...

Trichoepithelioma is a trichogenic tumor which arises from the inferior segment of hair follicle epithelium as hamartoma. Giant solitary trichoepithelioma is a distinct variant of trichoepithelioma. It has been defined as a solitary trichoepithelioma with a diameter greater than 2 cm [1]. It arises in elderly individuals and occurs mostly on the face, thigh and peri-anal region [2,3]. These fea...

background: busulfan (bus) is a chemotherapy drug that is widely used for cancer treatment. however, administration of busulfan may cause temporary or permanent sterility in male patients. therefore, reduction of this side is necessary. objective: evaluation of the protective effects of l-carnitine and testis homogenized tissue (tht) on sperm parameters and the testis structure after busulfan t...

PURPOSE To investigate the effects of human chorionic gonadotropin (hCG) on the testicular tissue of young male rats. METHODS Male Wistar rats were assigned to groups (10 rats/group).Control Group received subcutaneous saline solution; Group 1 received hCG 50 UI/Kg/dose; and Group 2 received hCG 100 UI/Kg/dose, daily for 15 days. Half was submitted to bilateral orchiectomy on the 16th day and...

Inhalation of nonisotonic solutions can elicit pulmonary obstruction in asthmatic airways. We evaluated the hypothesis that the respiratory epithelium is involved in responses of the airways to nonisotonic solutions using the guinea pig isolated, perfused trachea preparation to restrict applied agents to the mucosal (intraluminal) or serosal (extraluminal) surface of the airway. In methacholine...

objective: the environmental exposure to magnetic fields (mfs) may interact with biological systems. mfs are generated from various sources such as power lines, electric appliances at homes and offices, electrified transportation systems including urban railway systems and diagnostic devices such as magnetic resonance imaging (mri). there are some scientific evidences that imply the exposure to...

The number and distribution of mitotic epithelial cells in the ocular surface during homeostasis and in response to abrasion of the mammalian cornea were determined. Normal rats and those receiving a 3 mm diameter centrally located epithelial defect, received an intraperitoneal injection of colchicine 6 h prior to sacrifice. Mitosis in the basal epithelium during homeostasis was comparable in m...

esophagus having different tissues has a special role in the gastrointestinal tract. among different species, layers of the esophagus, have a substantial difference. also, diameter of esophagus varies in different parts of it.the information of histological structure of rabbit and guinea pig esophagus is still incomplete. therefore, the present study was conducted. therefore, for review and com...