Histopathological studies on experimental marine toxin poisoning--4. Pathogenesis of experimental maitotoxin poisoning

Repeated injections of 45 ng/kg of maitotoxin into the peritoneal cavities of male ICR mice resulted in marked atrophy of lymphoid tissues, a reduction of lymphocytes in the circulating blood, reduced immunoglobulin M in serum, and an increase of calcium content in the adrenal glands. A single injection of 200 ng/kg of maitotoxin induced a marked increase in total calcium content of the adrenal glands as well as in plasma cortisol concentration (about seven times control) within 1 hr. In contrast, mice pretreated with CoCl2, a calcium channel inhibitor, and/or adrenalectomized mice, showed no discernible changes in the lymphoid tissues after repeated injections of maitotoxin. It is thus suggested that maitotoxin first stimulates calcium influx in the adrenal glands, which then causes the release of cortisol into the blood. The excess amount of cortisol in serum produces acute involution of the thymus and other lymphoid tissues.     

Cervical lung hernia in a case of severe chronic asthma and bronchitis

A case of a bilateral pulmonary hernia of the lungs into the supraclavicular fossae is described. A man, aged 79, with severe chronic asthma and chronic bronchitis due to air pollution, complained of a cervical mass off and on for several years. The herniation was greater on the right side. It could be identified on physical examination by the presence of a soft painless supraclavicular bulge which was exaggerated by strain or cough. Radiologically this herniation could best be identified on lateral cervical roentgenogram. It is said that cervical lung hernia is a rare condition, but in our experience supraclavicular herniation of the lung is not unusual in cases of severe chronic obstructive lung disease.     

Lymphatic drainage of the gallbladder

Based upon detailed dissections of the lymphatic system in adult cadavers, the lymphatic drainage of the gallbladder was divided into three pathways: (1) The cholecystoretropancreatic pathway, which had two routes, one running spirally from the anterior surface of the common bile duct to the right rear, and the other running almost straight down from the posterior surface of the common bile duct. These routes converged at the principal retroportal node at the posterior surface of the head of the pancreas. (2) The cholecysto-celiac pathway; this was the route running to the left through the hepatoduodenal ligament to reach the celiac nodes. (3) The cholecysto-mesenteric pathway; this was the route running to the left in front of the portal vein to connect with the nodes at the superior mesenteric root. The cholecysto-retropancreatic pathway can be regarded as the main pathway, and the principal retroportal node appeared to be critical as the main terminal node in the visceral lymphatic system of the gallbladder. These three pathways converged with the abdomino-aortic lymph nodes near the left renal vein, and the nodes in the interaortico-caval space were considered to be of particular importance. Offprint requests to: M. Ito     

Presence of ghost cells and the Wnt signaling pathway in odontomas

BACKGROUND: Although it has been reported that ghost cells are present in odontomas, the generation mechanism of these cells is unclear. To evaluate the presence of ghost cells and involvement of the Wnt signaling pathway, we examined the expression of hard keratins, beta-catenin and Lef-1 in odontomas. METHODS: Sixty-nine cases of odontoma were examined immunohistochemically with the use of antibodies against human hair proteins, beta-catenin and Lef-1. RESULTS: Expression of hard keratins was found only in the cytoplasm of ghost cells in 46 (66.7%) of the 69 odontomas. Compound odontomas (78.8%) showed a higher incidence of ghost cells than complex odontomas (29.4%). Histopathologically, ghost cells were found within odontogenic epithelium adjacent to immature enamel and in the centre of Liesegang-ring-like calcified materials. Expression of beta-catenin and Lef-1 was observed in the cytoplasm and nucleus of odontogenic epithelial cells adjacent to the ghost cells in immature odontomas. CONCLUSION: These findings suggest that odontoma is a hard keratin-expressing tumor-like lesion, and that the Wnt signaling pathway may be involved in the formation of ghost cells in odontomas.     

Pancreatic tumor antigen in transplantable adenocarcinomas induced by N-bis(2-hydroxypropyl)nitrosamine in hamsters

An attempt was made to detect a pancreatic tumor antigen (PTA) in transplantable pancreatic adenocarcinomas induced by N-bis(2-hydroxypropyl)nitrosamine (DHPN) in hamsters. Antibody against antigenic protein was raised by immunizing rabbits with whole homogenate of the tumors transplanted into the back of hamsters. PTA was purified by affinity chromatography and shown to have the physicochemical properties of a glycoprotein with a molecular weight of 800,000, migrating in the beta regions upon agarose gel electrophoresis. Loss of immunological properties was observed after heating at 65 degrees C for 30 min. Enzyme immunoassay revealed that the levels of PTA in the serum and tissue showed a positive correlation with the induction of the presence of tumor, and size of the tumor. It is tentatively suggested that PTA values above 150 ng/ml serum are indicators of tumors, because in normal hamsters the PTA range is from 25 to 130 ng/ml serum. Immunohistochemically, PTA was demonstrated to be localized within the cytoplasm of epithelial tumor cells of well-differentiated tubular adenocarcinomas.     

Functional innervation patterns in the corpus spongiosum and glans in the dog

The neural control of smooth muscle cells in the corpus spongiosum, helicine artery and bulbus glandis of the dog was investigated in relation to the mechanism involved in erection, using isometric tension recording and micro-electrode methods. In the corpus spongiosum, field stimulation evoked twitch-like contractions followed by relaxations. These relaxations were enhanced and prolonged by neostigmine and partly suppressed by atropine. Guanethidine abolished the twitch-like contractions and increased muscle tone. The relaxations observed after pre-treatment with guanethidine were abolished by tetrodotoxin (TTX), thereby indicating that these muscles are innervated by adrenergic excitatory, cholinergic and non-adrenergic non-cholinergic inhibitory nerves. In the helicine artery and bulbus glandis, field stimulation evoked contractions and these contractions were abolished by guanethidine or TTX, indicating that these muscles are innervated by adrenergic excitatory nerve fibres. After pre-treatment with guanethidine and atropine, muscle relaxation appeared in response to field stimulation in the helicine artery but not in the bulbus glandis, indicating that the helicine artery in the corpus spongiosum is also innervated by non-adrenergic non-cholinergic inhibitory nerves in addition to the excitatory adrenergic nerves. In the smooth muscle cells of the corpus spongiosum, slow potential changes were correlated with spontaneous contractions and field stimulation evoked excitatory or inhibitory junction potentials. The neural mechanism involved in erection is discussed in relation to the topical difference in the autonomic innervation patterns in the corpus spongiosum, helicine artery and bulbus glandis.