Mariko Oishi

Primary Intrasellar Microgerminoma Detected by Magnetic Resonance Imaging: Case Report

A case of primary intrasellar germinoma in a 24-year-old woman is presented. Her initial symptoms were diabetes insipidus and headaches. The neurological examination found no abnormalities, but the endocrinological examination disclosed a deficiency in growth hormone secretion. Her skull x-ray revealed a normal sella turcica, and a computed tomographic scan revealed no abnormal mass in the pituitary fossa, but a slightly enlarged stalk. Magnetic resonance imaging revealed a small tumor in the posterior lobe. Transsphenoidal exploration revealed a germinoma in the posterior pituitary lobe. Six cases of primary intrasellar germinoma, including our case, were reviewed. Our case is considered to be the smallest intrasellar germinoma yet reported.

Fear of hypoglycemia and its determinants in insulin‐treated patients with type 2 diabetes mellitus

The aim of the present study was to investigate the prevalence of fear of hypoglycemia, in association with severe hypoglycemia and social factors, in insulin‐treated patients with type 2 diabetes mellitus. A questionnaire survey on hypoglycemia and patient–physician communication was carried out in 355 patients with insulin‐treated type 2 diabetes mellitus patients at 16 hospitals and clinics. A fear of hypoglycemia was reported by 27.7% of patients. A stepwise logistic regression analysis found that severe hypoglycemia during the past 1 year was a significant determinant of fear of hypoglycemia (odds ratio 2.16, 95% confidence interval 1.06–4.41; P = 0.034), and age (odds ratio 1.02, 95% confidence interval 1.00–1.05, P = 0.038) and living alone (odds ratio 1.93, 95% confidence interval 1.00–3.73, P < 0.05) were significantly higher in patients with fear of hypoglycemia than in those without it.

Release of histamine and adrenaline in vivo following intravenous administration of neurotensin

Plasma histamine levels of rats anesthetized with pentobarbital sodium were significantly increased by intravenous administration of neurotensin (NT, 1 nmole/kg) with the maximum effect at 3 min, and a return to the initial levels in 20 min. Treatment of animals with compound 48/80 or disodium cromoglycate completely inhibited the elevation of histamine level by NT, however, treatment with reserpine or diphenhydramine and adrenalectomy did not affect the elevation. Plasma adrenaline levels increased transiently 1 min after NT injection, and adrenalectomy and treatment with compound 48/80 or diphenhydramine markedly reduced the elevation of adrenaline levels after NT injection. Plasma levels of noradrenaline were unchanged upon NT injection. These results provide direct evidence of the release of endogenous histamine and adrenaline following NT administration, and suggest the contribution of these amines to the NT-induced triphasic blood pressure responses (the first depressor, second pressor and third depressor responses) reported previously.

Glucagon Underutilized Among Type 1 Diabetes Mellitus Patients in Japan

AIM Glucagon is recommended to treat severe hypoglycemia in nonhospital environments, when a patient with type 1 diabetes mellitus (T1DM) is unconscious and unable to eat or drink. However, the actual possession rate of glucagon in Japan has not been investigated. SUBJECTS AND METHODS We recruited 208 T1DM patients older than 15 years of age. The patients were treated at 16 hospitals and clinics in different regions of Japan. Answers were obtained using a self-administered questionnaire about the possession, the experience of usage, and the preference to possess glucagon after reading what is glucagon and when it is used. A stepwise logistic regression analysis was performed to assess the influence of various factors on the possession of glucagon. RESULTS The possession rate of glucagon was 15.9%, and the rate of those who had experience of using glucagon to treat severe hypoglycemia was 6.0%. The rate of preference to possess glucagon at home after reading the description of glucagon was 39.0%. The possession of glucagon was significantly associated with results of the Glucagon Knowledge Test (odds ratio=24.1; 95% confidence interval, 3.2-183.3; P=0.002) and the history of severe hypoglycemia within 1 year (odds ratio=4.8; 95% confidence interval, 2.0-12.0; P=0.001). CONCLUSIONS Glucagon as a measure to treat severe hypoglycemia was underutilized among T1DM patients in Japan.

Attenuation of triphasic blood pressure responses induced by shortening of amino acid sequences of neurotensin

Abstract Effects of neurotensin (NT) fragments on systemic blood pressure were investigated in anesthetized rats. NT (1–10 nmole/kg i.v.) produced triphasic blood pressure responses: the first depressor, second pressor and third depressor responses. Fragments of NT, NT2–13 and NT4–13, exhibited similar activities as NT in the first depressor phase, however, their potencies in the second pressor and third depressor phases were less than those of NT. Shorter fragments from NT5–13 to NT9–13 had reduced potencies in all three phases, especially in the second and third phases, depending on the length of amino acid sequences. A large dose of NT9–13 (100 nmole/kg) produced only the first depressor response, and NT10–13 failed to show any responses in blood pressure. Thus, the attenuation of the blood pressure responses induced by shortening of amino acid sequences of NT was prominent in the second and third phases. The present results support the hypothesis in our previous paper, that different mechanisms are involved in the three phases of blood pressure.

Influence of histamine and prostaglandin on desensitization to neurotensin in rat blood pressure

Triphasic depressor-pressor-depressor blood pressure responses to neurotensin (NT: 1.67 micrograms/kg i.v.) in anesthetized rats were not elicited when the second dose of NT was administered 20 min after the first injection. Pretreatment of animals with histamine markedly reduced the depressor response to NT, and vice versa. The triphasic blood pressure pattern remained unaffected with acetylcholine and serotonin treatment, and hypotensive effects of acetylcholine and serotonin were not modified by NT. Attenuation of depressor response induced by the second injection of NT was antagonized by pretreatment with prostaglandin synthesis inhibitors such as indomethacin, mefenamic acid and acetylsalicylic acid. These results suggest that histamine and prostaglandins play a role in the development of desensitization to NT in rat blood pressure.