Histochemical studies of myocardial injury caused by hydrogen peroxide after reperfusion using the cerium method

Free radicals have been implicated in myocardial reperfusion injury. Hydrogen peroxide (H₂O₂) is a precursor of highly reactive oxygen intermediates. In this study, we investigated myocardial injury caused by endogenous H₂O₂ during the early reperfusion period following brief ischemia with electron microscopy and the cerium method. This method involves formation of an electrondense precipitate when H₂O₂ reacts with cerium chloride (CeCl₃). We used isolated, functioning hearts prepared according to the working heart model, which were reperfused with a solution containing 0.5mM CeCl₃ for 5 min after 10 min of ischemia. Some hearts were treated with 3-amino-1,2,4-triazole (ATZ) to inhibit catalase; others were treated with ATZ and superoxide dismutase (SOD), which dismutates the superoxide anion to hydrogen peroxide. In the control group (no drugs given) and the ATZ-treated group, the CeCl₃–H₂O₂-dependent reaction products during the reperfusion period appeared in 12% and 28%, respectively, of the microvascular spaces. Treatment with SOD did not produce a decrease in electron-dense precipitates or a decrease in myocardial injury during ischemia-reperfusion. Moreover, in the ATZ group, moderately injured myocytes were seen (swelling of mitocondria, intermyofibrillar edema). Our results indicate that in myocytes, catalase plays an important role in the defense against H₂O₂ and that the increase in H₂O₂ is a cause of reperfusion injury. However, SOD does not protect against H₂O₂ in the absence of catalase.This study was presented in part at the 27th Annual Meeting of the Clinical Electron Microscopy Society of Japan, Kurashiki, September 29, 1995     

Meniere's disease in Uppsala and Osaka. A comparative study

A total of 100 patients with Meniere's disease, 50 at the University Hospital of Uppsala and 50 at the Osaka City University Hospital, were submitted to a test battery using the same methods, and the results obtained at the two hospitals were compared. Briefly the findings were as follows. There was no significant difference in age at examination or in the duration of illness. No significant difference was detected with regard to a) the average hearing loss or the types of audiogram, b) the incidence of spontaneous or positional nystagmus, or c) caloric and optokinetic test results. A linear correlation was found between caloric responses and pure tone audiograms in both the Uppsala and Osaka patients.     

Recovery process of tracheal mucosa of guinea pigs exposed to isopropyl alcohol

The toxicity of isopropyl alcohol (IPA) on the tracheal mucosa was studied experimentally with special reference to the recovery process of the organ. The results showed that 400 ppm IPA has an acute effect on the mucociliary system in the tracheal mucosa, and that recovery from such degeneration can occur in 2 weeks. When functional and morphological damage was induced by a higher level (5500 ppm) of IPA, recovery did not occur in 2 weeks. The conclusion is that the present allowable level of IPA is reasonable from the viewpoint of the effects of short-term exposure to IPA on the tracheal mucosa. In addition, a higher level of IPA exposure has longer-term effects on the tracheal mucosa, and workers exposed to such a higher level of IPA vapor should be given careful otolaryngological follow-up observations.     

A novel tumor-associated protein: clinical significance of serum levels in various clinical conditions with special reference to gynecological malignant diseases.

A novel tumor-associated protein (TAP), that was originally detected immunologically through the use of a monospecific antiserum against a placental antigen, was quantified by means of the rocket technique of Laurell. Four hundred and fifty-seven serum samples were obtained from healthy female subjects (55), and patients with leiomyomas (162), benign ovarian tumors (78), pelvic endometriosis (45), cervical cancer (73), endometrial cancer (18) and ovarian cancer (26), respectively. Statistical analysis showed that TAP exhibited the closest relationship in ovarian cancer patients in whom the appearance of TAP and its high level were most prominent. The present preliminary study suggests the clinical usefulness of this protein as a clinical adjunct for the management of ovarian cancer.     

A case of mesenteric lymphadenitis with long-acting symptom, showing marked response to corticosteroid.

A 17-year-old girl who had right lower abdominal pain with multiple swelling of lymph nodes in the ileocecal region and she was admitted to a neighboring hospital. Since there was no improvement of condition with antibiotic resistance, we were consulted. Lymph node biopsy under laparoscopy demonstrated nonspecific findings. She then developed erythema nodosum, suggesting the presence of autoimmune etiology. Treatment with systemic corticosteroid resulted in symptomatic improvement. Mesenteric lymphadenitis like this case is rare.     

5-Hydroxytryptamine innervation of vessels in the rat cerebral cortex. Immunohistochemical findings and hydrogen clearance study of rCBF

The role of the central 5-hydroxytryptamine (5-HT) neuron system in cerebral microcirculation of the rat was examined by immunohistochemical and hydrogen clearance methods. Immunohistochemical studies demonstrated 5-HT-immunoreactive nerve fibers along intraparenchymal blood vessels (arterioles, capillaries, and venules). Ultrastructural observation revealed that 5-HT-immunoreactive terminal boutons (0.3 to 1.0 micron in diameter) made contact with the basement membrane of the capillaries. After an intracerebral injection of 5,7-dihydroxytryptamine (5,7-DHT), a neurotoxin to the 5-HT neuron system, no 5-HT-immunoreactive nerve fibers were found around the injection site with immunohistochemical techniques. With the hydrogen clearance method, the 5,7-DHT-injected cortex showed no significant change in regional cerebral blood flow (rCBF) in the presence of normocapnia, but a significant increase in rCBF with hypercapnia, compared with the untreated cortex. These facts strongly suggest that the central 5-HT neuron system has an important role in carbon dioxide reactivity of the cerebral blood vessels.