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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 19 recordsLinked to original sources
PubMed1992

[A case of insulinoma with frequent hypoglycemic attacks not showing evident hyperinsulinemia].

Confirmation of inappropriate hyperinsulinemia is an indispensable requisite for the diagnosis of insulinoma. We report here a case of insulinoma without evident hyperinsulinemia at an early stage. The patient, a 49-year-old woman, had been admitted to our hospital for the evaluation of frequent hypoglycemic attacks. At that time, plasma immunoreactive insulin (IRI) after an overnight fast ranged from 7 to 16 microU/ml. The ratio of IRI/fasting blood sugar (FBS) (Fajans index; normal range, below 0.3) was always between 0.13 and 0.28 even at hypoglycemic states. In addition, because computed tomography and arteriography of the abdomen failed to settle the diagnosis of insulinoma, the patient was discharged and followed up at our outpatient clinic for 2 years. She was admitted to our hospital at 51 years of age for the re-evaluation of hypoglycemic attacks. Laboratory examinations revealed high fasting plasma levels of IRI ranging from 20 to 29 microU/ml. Fajans index also increased to 0.47-0.89. Celiac arteriography was able to confirm the existence of insulinoma. We suggest that insulinoma should be considered in the presence of unexplained hypoglycemic attacks even when there is no evident hyperinsulinemia.

Blood Glucose↗
PubMed1992

[Radiation management of retinoblastoma].

Forty-five patients with retinoblastoma were treated at Keio University Hospital from 1970 to 1990. Thirty-two patients had unilateral lesions and 13 had bilateral lesions. Twenty-nine patients with unilateral and 12 with bilateral lesions underwent enucleation for advanced tumor. As a result, 3 patients with unilateral retinoblastoma and all patients with bilateral disease were treated with radiotherapy (40-50 Gy) combined with or without cryotherapy and/or photocoagulation. One patient with unilateral lesion treated with radiotherapy and chemotherapy had metastases at the first visit to our clinic and was excluded from this analysis. Among 16 eyes (15 patients) treated with radiotherapy, 6 eyes had recurrence and needed retreatment. Cataract occurred in 6 of 12 eyes and good vision was preserved in 5 of 10 eyes in which function could be evaluated.

Child, Preschool↗
PubMed1992

[Experimental studies on metastases from an irradiated tumor].

This study was carried out to determine the effect of irradiation of a tumor on the development of lung metastases. SANH, a spontaneous sarcoma, was isotransplanted in the right thighs of C3H mice which were either locally preirradiated (30 Gy: TBR) or non-irradiated. When the tumors had grown to 7 mm in diameter, they received 20-30 Gy of electron beams (RTx). The tumor-bearing legs were amputated at various tumor sizes, and the incidence of metastasis and number of lung nodules were compared in each treatment group. The incidences of metastases from 7 mm tumors in mice with regrowing tumors after RTx (30 Gy) and non-irradiated mice were 28% and 4%, respectively. When tumors grown in preirradiated legs were removed at 7 mm in diameter, the incidence of metastases (58%) was also enhanced by preirradiation of the tumor bed. Seven millimeter tumors that were growing in TBR legs and received RTx (20 Gy) developed a higher incidence (82%) and greater numbers of metastases than either the RTx or TBR groups. To determine the relationship between the interval of tumor bearing and development of metastases, tumors were removed at various intervals after tumor transplantation in 4 groups, namely, non-irradiated, TBR, RTx and TBR with 20 GyRTx. Lung metastases came later but increased steeply in mice given either TBR or RTx, compared with non-irradiated mice. Tumors growing in TBR and receiving RTx (20 Gy) developed many more metastases than any other group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Inhibitory effect of inaperisone hydrochloride (inaperisone), a new centrally acting muscle relaxant, on the micturition reflex.

We examined the effects of inaperisone hydrochloride (inaperisone), a new centrally acting muscle relaxant, on bladder function in anesthetized rats and isolated rat tissues. We also investigated its mechanism of action. When a balloon inserted into the bladder was expanded, rhythmic bladder contractions were observed; inaperisone (4 mg/kg i.v.) abolished these contractions, in both normal and decerebrated rats. The bladder tonus or bladder contraction induced by peripheral stimulation of the pelvic nerve was barely inhibited by inaperisone (4 mg/kg i.v.), but this dose of inaperisone abolished the efferent discharge from the pelvic nerve that accompanied the rhythmic bladder contractions. The doses of intracerebroventricularly (i.c.v.) and intrathecally injected inaperisone which abolished the rhythmic bladder contractions were 10 and 100 micrograms, respectively. The inhibitory effects of inaperisone (4 mg/kg i.v.) were not diminished by naloxone (1 mg/kg i.v.) or by bicuculline (0.5 mg/kg i.v.), but were diminished by phaclofen (30 mg/kg i.v. or 300 micrograms i.c.v.). The specific binding of [3H]baclofen to rat brain synaptosomal membranes was barely inhibited by inaperisone (up to 1 mM). From these results, it is speculated that, among other possible mechanisms, inaperisone inhibits the micturition reflex by acting indirectly on GABAB receptors in the brainstem.

Anesthesia↗
PubMed1992

[Percutaneous transluminal angioplasty for stenotic dialysis arterio-venous fistulas].

From December 1982 to January 1991, we performed fistulography on 40 patients who complained functional failure of arterio-venous dialysis fistula. And percutaneous transluminal angioplasty (PTA) was attempted on 15 patients (19 times) who revealed marked fistula stenosis. Initial successful rate was 78.9% and patency rate was 56.2% in the first 6 months. (75% in the first 6 months when angioplasty was initially successful). We describe the method of fistulography and PTA for stenotic dialysis fistulas, and evaluate the usefulness of PTA. And also we introduce our attempts for improving the initial successful rate and patency rate. In conclusion, when dialysis arterio-venous fistula is stenotic but not occlusive, PTA should be considered first before surgical treatment is done.

Adult↗
PubMed1992

Neurogenic responses of urethra isolated from the dog.

Electrical transmural stimulation evoked contraction and relaxation in isolated urethral circular muscle of the dog. The responses were abolished by tetrodotoxin, indicating their neurogenic origin. The contractile force in the middle urethra was greater than that in the proximal and distal urethra. The contractions were not affected by atropine and propranolol, but were completely inhibited by phenoxybenzamine, prazosin and guanethidine. In preparations contracted with prostaglandin F2 alpha, electrical stimulation induced frequency-dependent relaxation in all urethral portions. Atropine, phenoxybenzamine, prazosin and guanethidine had no effect on the relaxation, while propranolol slightly attenuated the relaxation induced at the highest frequency used (5 Hz). The non-adrenergic, non-cholinergic relaxation was also not affected by ketanserin, methysergide, diphenhydramine, alpha,beta-methylene ATP or capsaicin. Exogenously applied phenylephrine and clonidine both produced contractions but the maximal response to clonidine was much smaller than that to phenylephrine. Acetylcholine produced no or feeble contractions. In the preparations contracted with prostaglandin F2 alpha, isoproterenol and vasoactive intestinal polypeptide (VIP) produced relaxation. These results suggest that the circular muscle of dog urethra is reciprocally innervated by sympathetic adrenergic and non-adrenergic, non-cholinergic nerves, and that the neurogenic responses are markedly affected by muscle tension and the portion of the urethra examined.

Animals↗
PubMed1992

Macrophage differentiation-specific expression of NF-IL6, a transcription factor for interleukin-6.

NF-IL6 was originally identified as a DNA binding protein regulating interleukin-1 (IL-1)-stimulated IL-6 expression. Direct cloning of NF-IL6 showed its homology with C/EBP, a hepatocyte- and adipocyte-specific transcription factor. This study showed that the expression of NF-IL6 messenger RNA (mRNA) increased markedly during the differentiation to a (mRNA) increased markedly during the differentiation to a macrophage lineage in mouse myeloid leukemia cells M1, human histiocytic leukemia cells U937, promyelocytic leukemia cells HL-60, and human peripheral monocytes. Particularly in HL-60 cells that undergo granulocyte or macrophage differentiation depending on inducers, NF-IL6 mRNA was specifically upregulated during macrophage differentiation but not granulocyte differentiation. It was also shown that the functional NF-IL6 protein increased during the differentiation of U937 cells. Furthermore, recombinant NF-IL6 was found to bind to the regulatory regions of the IL-1, tumor necrosis factor, granulocyte colony-stimulating factor, and lysozyme genes, which are expressed in mature macrophages. These results suggest that NF-IL6 may possibly be involved as an important transcription factor in the process of activation and/or differentiation of macrophages.

Animals↗
PubMed1992

Possible model for generation of P9 far-field potentials.

The distribution of P9 far-field somatosensory evoked potentials, after stimulation of the median nerve with a knee reference, was examined to determine the mechanism of the generation of P9 potentials. In addition to positive potentials (P9s), we found a negative potential (N9) recorded from the chest ipsilateral to the stimulation. The simulation of the distribution of these P9/N9 potentials by an electrical circuit diagram suggested the validity of this model for generation of the P9s.

Electric Stimulation↗
PubMed1992

Cumulative white matter changes in the gerbil brain under chronic cerebral hypoperfusion.

An animal model of chronic brain hypoperfusion has been developed by applying coiled clips to the bilateral carotid artery of Mongolian gerbils. The brain tissue damage was neuropathologically studied after 1, 4, 8, and 12 weeks of hypoperfusion. The hippocampus, basal ganglia, and cerebral cortex of the chronically hypoperfused gerbil showed lesions with various severity which are probably due to ischemic episodes. In the cerebral white matter, however, two types of lesions were observed; one similar to those in the gray matter, and the other observed only in the white matter after more than an 8-week duration of brain hypoperfusion. The lesion specific to the white matter showed rarefaction and gliosis without locally associated ischemic changes. This type of the white matter lesion was never found in the gerbil brain before 8 weeks and, significantly, increased in number and size by 12 weeks post operation. The accumulation of the white matter lesions is characteristic in the gerbil with chronic hypoperfusion. The observed white matter-specific lesion resembles the histological changes in aged brain with cerebrovascular diseases.

Animals↗
PubMed1992

Transcatheter hepatic arterial chemoembolization using epirubicin-lipiodol: experimental and pharmacological evaluation.

The experimental and pharmacological characteristics of various formulations of an anticancer agent (epirubicin, EPI) and lipiodol were evaluated in vitro and in vivo. Three forms of EPI-lipiodol, i.e., an oil-in-water type of emulsion (O/W type), a water-in-oil type of emulsion (W/O type), and a suspension (S type), were prepared and investigated for their stability. An O/W-type emulsion using a stock solution of Iopamidol as the solvent for EPI was the most stable form in the stationary state in vitro. In 16 patients with malignant liver tumors (14 hepatocellular carcinomas and 2 liver metastases), the three forms of EPI-lipiodol were injected into the proper hepatic artery. The plasma EPI level was monitored periodically and analyzed pharmacokinetically. No significant difference in the pharmacokinetics of EPI was detected among the O/W, W/O, and S types.

Aged↗