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Biomedical subjects

H Tamai

Publications and source records attributed to H Tamai.

At least 253 records · Page 14Linked to original sources

Malignant lymphoma of the thyroid and Epstein-Barr virus.

We have investigated the specific immune response to Epstein-Barr virus (EBV) of peripheral blood mononuclear cells (PBMC) from patients with malignant lymphoma of the thyroid. Coculture of PBMC and EBV resulted in EBV cell transformation and regression which was assayed by an EBV-induced B cell focus-regression assay technique. The EBV had been isolated from mouthwash samples. The specific immune response to EBV by outgrowth inhibition in PBMC from untreated EBV-seropositive patients with malignant lymphoma was significantly decreased when compared to PBMC from EBV-seropositive healthy subjects (p less than 0.05). This observation is at least consistent with the possibility that B-cell proliferation after continuous or recurrent EBV infection could be a causative factor or may potentiate malignant lymphoma of the thyroid.

Aged↗

Impaired glucagon secretion to insulin-induced hypoglycemia in anorexia nervosa.

In order to clarify the role played by pancreatic alpha-cell dysfunction in the impaired glucose recovery from hypoglycemia in patients with anorexia nervosa, the response of pancreatic alpha-cells to insulin-induced hypoglycemia was investigated in 16 patients with anorexia nervosa before and after treatment. The results were compared with those obtained after loading with arginine. Before treatment, despite comparable falls in plasma glucose levels, glucagon secretion was significantly reduced in the anorectic patients compared with control subjects. In addition, glucose recovery from hypoglycemia in the patients was attenuated. However, after treatment, both glucagon secretory activity and plasma glucose recovery following insulin-induced hypoglycemia were restored to normal. Plasma glucagon responses to arginine infusion were not significantly different in the untreated anorectic patients and control subjects. However, the plasma insulin response in the patients was significantly lower than in the control group. These results suggest that the impaired recovery of plasma glucose levels from insulin-induced hypoglycemia in patients with anorexia nervosa is primarily attributable to impaired pancreatic alpha-secretory capability. In addition, this abnormality in pancreatic alpha-cell function is reversible with treatment leading to improved nutrition and weight gain.

Adolescent↗

[M. kansasii lung infection occurring in a compromised host with idiopathic pulmonary fibrosis].

A 61-year-old man was admitted to our hospital because of persisting cough, sputum and shortness of breath for four months. Brushing specimens and BALF bronchoscopically obtained revealed acid-fast bacilli and TBLB showed pathological findings consistent with interstitial pneumonia. Based on these results, clinical symptoms, chest roentgenograms on admission and identification of M. kansasii, a diagnosis of M. kansasii lung infection occurred in idiopathic pulmonary fibrosis was made. The patient's symptoms consistent with M. kansasii lung infection and his sputum became negative 6 weeks after antituberculosis chemotherapy with INH, SM and RFP. Because of an increasing dyspnea due to pulmonary fibrosis, however, the patient received oxygen therapy. This case suggested an increasing tendency of compromised hosts associated with M. kansasii lung infection.

Humans↗

[A brief respite from hospital: home mechanical ventilation for children in Japan].

Children who require prolonged respiratory support often have to spend their whole lives in the hospital. It is important, however, for these children to have time with their families in their own homes. Home mechanical ventilation can make it possible. In Japan, the concept of home mechanical ventilation has just begun to open up. We reported five cases of home mechanical ventilation for children by using a portable respirator (Bennett, Companion 2800). Two cases of these were patients with hypoxic ischemic encephalopathy. The others were cases with neuro-muscular diseases (Werdnig-Hoffmann disease, mitochondrial myopathy, myotubular myopathy). Before taking the patients out, parents received a training in nursing procedures and in skillful use of the ventilator and equipment. The patients went out on excursions 17 times, and were released for home stay a total of 25 times. Initially, 12 excursions were undertaken with doctors or nurses in attendance; later, however, all of the home stays and 5 of the excursions were carried out successfully by the family only. They went to places such as their own home, a park, a zoo, an aquarium and a museum. The average time was 4.6 hours (3-8 hours) for excursions, and 1.8 days (1-7 days) for home stays. Questioning of family revealed that home mechanical ventilation accelerated the social and emotional development of these children whose condition necessitated respiratory support, especially patients with neuro-muscular diseases. It also revealed that family could accept the patient as a member with more familiarity and with more ease.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗

Thyroidal prelymphoma.

We treated a 32-year-old man with "thyroidal prelymphoma", morphologically resembling Hashimoto's thyroiditis and associated with monoclonal gammopathy (IgG, lambda). Immunohistochemistry revealed intracytoplasmatic monoclonal immunoglobulin (IgG, lambda) containing lymphoid cells in the interstitium of the thyroid tissue. After total thyroidectomy had been performed, the monoclonal immunoglobulin disappeared. Three years have passed since the surgery and this writing, there has been no recurrence. The existence of thyroidal prelymphoma suggests that chronic antigenic stimulation might produce lymphocytes which are more susceptible to neoplastic change (Hashimoto's thyroiditis----thyroidal prelymphoma----malignant lymphoma of the thyroid).

Adult↗

Theoretical analysis of a site-specific chemiluminescence reaction and its application to quantitation of lipid hydroperoxides.

A system was designed for chemiluminescent measurement of lipid hydroperoxides by their site-specific reaction in sodium dodecylsulfate micelles. Ferrous ion-induced decomposition of lipid hydroperoxides in the sodium dodecylsulfate micelles resulted in strong chemiluminescence of the Cypridina luciferin analog, 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (CLA). After addition of ferrous sulfate to the micelles containing lipid hydroperoxide and luciferin, the chemiluminescence intensity reached a maximum rapidly and then decreased. The sequence of this reaction was elucidated by theoretical analysis, which demonstrated that the maximum chemiluminescence intensity is proportional to the initial concentration of hydroperoxide. Good linear relationships were observed between the maximum counts of chemiluminescence and the amounts of hydroperoxides of linoleic acid, phosphatidylcholine, choresterol (5 alpha), cumene and tert-butyl and hydrogen peroxide. This chemiluminescence method was simple and sensitive enough to detect picomole levels of linoleic acid and phosphatidylcholine hydroperoxides.

Binding Sites↗

The moment of intraventricular hemorrhage.

A continuous monitoring of the germinal layer by linear scanning ultrasound has been proposed for the purpose of ascertaining the moment of intraventricular hemorrhage (IVH). Using a VHS videotape, we performed the 48 hours monitoring in 7 immature infants weighing less than 1,000 g who required respiratory support. Four cases of these developed IVH. In one case, which was 755 g in birth weight and 24 weeks in gestational age, the moment of IVH was successfully demonstrated on the ultrasonic monitor. At that moment, there were no significant changes in heart rate and systemic blood pressure. No direct manipulation or treatment, such as an endotracheal suctioning or a heel puncture which might induce a blood pressure fluctuation, was being given at the moment of IVH. About 15 minutes after the episode, abnormal seizure-like movement periodically developed.

Blood Pressure↗

Human atrial natriuretic polypeptide in plasma of patients with anorexia nervosa.

To examine the effects of chronic dehydration and starvation on plasma levels of human atrial natriuretic polypeptide (hANP) in human subjects, the basal level and saline-induced rise of plasma hANP in 7 patients with anorexia nervosa were compared with those in age-matched healthy subjects. The unstimulated level of plasma hANP was markedly high in the patients with anorexia nervosa (patients vs. control; 55.4 +/- 9.0 pg/ml vs. 11.4 +/- 6.1 pg/ml, P less than 0.01). However, no significant increase of plasma hANP in the anorectic patients was observed in response to saline-infusion, while a 3-fold increase over the basal level of plasma hANP was noted in the saline-infused normal young subjects. These results show that hANP may be secreted to an inadequate extent, hence the release would be resistant to volume-loading. The pathophysiological meaning of such a high plasma concentrations of hANP in anorexia nervosa is the subject of ongoing studies.

Adolescent↗

Angiotensin-converting enzyme and anorexia nervosa.

Angiotensin-converting enzyme (ACE) activity was measured in 10 patients with anorexia nervosa, 6 with hyperthyroid Graves' disease, and 7 with primary hypothyroidism. Patients with anorexia nervosa had a low serum ACE activity (9.8 +/- 2.2 IU/l), as compared to findings in normal subjects (13.4 +/- 3.5 IU/l) (P less than 0.05). Patients with hyperthyroid Graves' disease had high serum ACE activity (23.7 +/- 5.8 IU/l), as compared to levels in normal subjects (P less than 0.01), and patients with primary hypothyroidism tended to have low serum ACE activity (10.1 +/- 1.8 IU/l), compared to the normal subjects (P less than 0.1). Following weight gain (before; 71.3 +/- 10.2% of ideal body weight, after; 88.7 +/- 5.6% of ideal body weight), serum ACE activity in patients with anorexia nervosa reverted to within the normal range (13.8 +/- 3.5 IU/l), and serum T3 concentration was restored to the normal range (before; 0.7 +/- 0.2 ng/ml, after; 1.1 +/- 0.3 ng/ml). In these patients, ACE activity correlated with the per cent of ideal body weight (P less than 0.05). These data suggest that, in underweight subjects with anorexia nervosa, decreased serum ACE activities may relate to emaciation.

Adolescent↗

Glucagon secretion in anorexia nervosa.

Patients with anorexia nervosa frequently manifest impaired glucose tolerance. However, alterations in pancreatic glucagon secretion have also been associated with alterations in diabetes mellitus. For this reason, pancreatic alpha- and beta-cell responses to glucose load were measured in 25 anorexic patients both before and after treatment. The baseline glucose challenge failed to suppress plasma glucagon levels in the patients. However, in the control subjects and patients after treatment, glucagon levels were suppressed after glucose ingestion. Plasma glucose levels during the baseline challenge were significantly higher than those of the control subjects; however, after treatment glucose responses were nearly normal. Finally, insulin responses at baseline and after treatment were lower in the patients than in control subjects. These results suggest that the impaired glucose tolerance manifested by anorexic patients may be attributable to significant alterations in both pancreatic alpha- and beta-cell secretions and in pancreatic alpha-cell and glucose interrelationships.

Analysis of Variance↗

Hypothalamic-pituitary-thyroidal axis alterations in bulimic patients.

The hypothalamic-pituitary-thyroidal axis was studied in 17 normal-weight patients with bulimia. Basal levels of serum thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3), and thyrotropin (TSH) were determined in all patients; responses of TSH and T3 to thyrotropin-releasing hormone (TRH) were investigated in nine patients. Mean basal serum T4, T3, and TSH concentrations were significantly lower in the patients than in the normal control subjects but serum rT3 levels were essentially the same. In nine patients TSH responses to TRH were normal in five, delayed in three, and low in one. The maximum increase in serum TSH and TSH net secretory response were not significantly different from those of control subjects. With respect to the T3 response to TRH, various indices in patients appeared significantly lower than in the control subjects. These results suggest that normal-weight patients with bulimia have abnormalities in the hypothalamic-pituitary-thyroidal axis.

Adult↗

The dexamethasone suppression test for Japanese with eating disorders.

A one-mg oral overnight dexamethasone suppression test (DST) was conducted on 22 inpatients with eating disorders. To confirm that the dexamethasone tablets had been ingested, we measured the plasma concentrations of dexamethasone the next morning (at 0900 hr after DST). The diagnosis of anorexia nervosa and bulimia was made according to the criteria for DSM-III, respectively. Of the 22 patients with eating disorders, 16 satisfied the criteria for anorexia nervosa and 6 for bulimia. The DST was carried out within 2 weeks of hospitalization on each patient. The subjects were given 1 mg of dexamethasone in the evening (at 2300 hr) and blood samples were collected the following day (at 0900, 1600 and 2100 hr, respectively). The plasma cortisol and dexamethasone levels were concurrently determined by RIA. The criterion for non-suppression was a failure to suppress the plasma cortisol levels below 5.0 micrograms/dl in any one of the three samples. All but one patient with bulimia had ingested the dexamethasone. Thirteen (62%) of 21 patients with eating disorders were nonsuppressors. We found a significant positive correlation between the plasma cortisol levels at 1600 hr or 2100 hr and a decrease in ideal body weight (n = 16, r = 0.613, p less than 0.05; r = 0.75, p less than 0.01, respectively) and a significant inverse relationship between the plasma dexamethasone levels at 0900 hr and the plasma cortisol levels at 1600 hr was recognized (n = 21, r = 0.631, p less than 0.01). These results suggest that the blood dexamethasone levels as well as body weight might contribute to the abnormalities of DST seen in patients with eating disorders.

Anorexia Nervosa↗

Prolactin responses to hypoglycemia and thyrotropin-releasing hormone in anorexia nervosa.

Although prolactin (PRL) responses to thyrotropin-releasing hormone (TRH) have been described by many investigators, PRL secretion after insulin stimulation has rarely been documented in patients with anorexia nervosa (AN). We investigated PRL responses to TRH (500 micrograms) and insulin (0.1 U/kg) in 19 women with AN and 10 normal women. Levels of PRL stimulation at 60 min and later following insulin administration were significantly lower in AN than in normal women. PRL increased by at least 10 micrograms/ml after insulin in 42% of women with AN and in 70% of normal women. The maximum PRL increase (max delta PRL) did not differ after the two stimulations in the normal women. However, in AN, the max delta PRL after insulin stimulation (17.2 +/- 4.0 micrograms/l, mean +/- SEM) was significantly lower than that after TRH (49.1 +/- 6.4 micrograms/l). These findings suggest that anorectic women may have a disturbance in hypothalamic functions. Insulin-induced hypoglycemia is useful to determine the integrity of the hypothalamic-pituitary axis for PRL secretion, in combination with TRH stimulation.

Adolescent↗