Biomedical subjects
Publications and source records attributed to Y Kitahara.
We report a Garcin syndrome due to nasopharyngeal carcinoma invading the skull base. MR Imaging of this patient shows the position of the tumour and reveals how the tumor invaded the skull and the effect of treatment.
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The relation of plasma levels of atrial natriuretic peptide (ANP) to those of cyclic 3', 5'-guanosine monophosphate (cGMP) was studied in 43 patients with various heart diseases. Plasma levels of both ANP and cGMP were significantly (p less than 0.001) elevated in 34 patients with chronic heart diseases, and a significant positive correlation was observed between the two variables (r = 0.706, p less than 0.01). Clinical improvement of congestive heart failure resulted in a concomitant decrease in plasma ANP and cGMP levels in 6 patients. In 3 patients with paroxysmal atrial fibrillation, plasma levels of ANP and cGMP increased markedly during arrhythmia. These results indicate that increased circulating ANP may stimulate cGMP production in target cells, which in turn raises plasma levels of cGMP in humans.
Hematocrit (Hct) changes during mental stress were studied in 21 patients with mild hypertension. A 10 min arithmetic stress test increased blood pressure from 129 +/- 2/80 +/- 2 mmHg (mean +/- SEM) to 167 +/- 5/98 +/- 3 mmHg, and heart rate from 64 +/- 2 to 81 +/- 3 (p less than 0.001). Concomitantly, a significant (p less than 0.001) increase in Hct was observed (from 41.5 +/- 0.7% to 42.2 +/- 0.8%), and increments of Hct (-0.1% to 2.2%) were significantly (r = 0.61, p less than 0.01) correlated with those of systolic blood pressure. Plasma levels of norepinephrine (NE), epinephrine (E) and atrial natriuretic peptide (ANP) also showed a significant increase after mental stress. All these changes disappeared after a 60 min recovery period. The results suggest that mental stress increases Hct promptly, which may be due to concomitant increases in plasma NE, E and ANP levels. Hct elevation resulting from mental stress may be clinically relevant, at least, in hypertensive patients who are at risk of occlusive vascular diseases.
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Inhibition of avian myeloblastosis virus (AMV) reverse transcriptase by natural and synthetic quinones including antibiotics could be accounted for by an oxidation-reduction reaction. The quinones were shown to function as electron acceptors as revealed by the catalytic oxidation of NADH by Clostridium kluyveri diaphorase which was in excellent agreement with enzyme inhibition activity. The kinetics of inhibition of AMV reverse transcriptase by three synthetic quinones with different core structures, i.e., 6-methoxy-5,8-dihydroquinoline-5,8- dione, 5,8-dihydroisoquinoline-5,8-dione and 1,4-naphthoquinone, were studied. These quinones inhibited reverse transcriptase in the same manner as streptonigrin (STN) and were shown to act at a single class of reaction site(s) on the enzyme molecule. In contrast, the quinones with bulky substituents, i.e., 7-(2-nitrophenethylamino)-5,8-dihydroisoquinoline-5,8-dione and 7-methoxy-6-methyl-3-piperidino-5,8-dihydroisoquinoline-5,8-dione, were inactive as inhibitors of reverse transcriptase, whereas they retained competent catalytic activities in the oxidation of NADH by C. kluyveri diaphorase. Based on these observations, the existence of a specific site of interaction on the enzyme molecule, referred to as a quinone pocket, was proposed. The quinone pocket might play a crucial role in the early sequence of events leading to the inhibition of reverse transcriptase by quinones including STN and sakyomicin A (SKM). Access of SKM to a quinone pocket might be restricted due to its bulky structure in the vicinity of the quinone group. This is inferred from unsuccessful inhibition of reverse transcriptase by the quinones with bulky substituents, resulting in much poorer inhibition of reverse transcriptase in spite of more potent electron acceptor activity in the oxidation-reduction system as compared with those of STN.
The authors have experienced two cases of basal encephalocele without intra and extra cranial anomalies. We have reviewed previous reported cases and studied, from the view point of developmental pathology, reasons why these cases did not have associated anomalies. In this paper we will report our two cases of basal encephalocele and propose a new classification for it, based upon the developmental pathology of the basal part of the skull and associated anomalies. Case 1. A 32 year old male complained of continuous rhinorrhea for 8 months. Coronal CT scan demonstrated a defect of the right sphenoid and ethmoid bone, and a protrusion of isodensity mass, which was enhanced by administration of metrizamide in the subarachnoid space. During the operation, the protruded mass was removed, and the defects of bone and dura mater were repaired. Postoperative course was uneventful. Case 2. A 33 year old male was referred from the department of otology to the department of neurosurgery, because of rhinorrhea and the presence of brain tissue at the time of nasal operation 3 months before. Coronal CT scan revealed a defect of the left ethmoid bone and a protrusion of isodensity mass in it. RI cisternography clearly demonstrated the leakage of CSF through the left nasal cavity. During the operation, the protruded mass was removed and the bone and dura mater defects were repaired. Postoperative course was uneventful. The common findings of both cases are that they were diagnosed by accident in adulthood cases of rhinorrhea, and midsagittal basal bone structure was preserved without extra and intra cranial anomalies.(ABSTRACT TRUNCATED AT 250 WORDS)
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Sultamicillin (SBTPC) fine granules were given to 15 patients with respiratory tract infections at a dose of 375 mg 3 times a day. The results were excellent in 4 patients, good in 8, fair in 1 and poor in 2 with an efficacy rate of 80% which is comparable to that of SBTPC tablet (Unasyn tablet). One patient complained of difficulty in swallowing the drug probably due to its fine granular nature. No side effects nor abnormal laboratory test values due to this drug were observed in any of the patients enrolled in this study. From the above results, SBTPC fine granules seem to be useful in the treatment of pediatric and elderly patients who sometimes have difficulties in taking tablets.
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This report describes a case of secretory carcinoma of the breast in the adult. The patient, a 56-year-old female, had a tumor, 1 cm in size, in the upper outer quadrant of her left breast, and Patey's modified radical mastectomy was performed. No nodal metastases were found. Although secretory carcinoma of the breast has been called "juvenile carcinoma", 27 adult cases have been reported previously in the English and Japanese literature. It is reported to have a good prognosis but surgical therapy with an axillary node dissection is recommended, since axillary metastases have been found in approximately 30% of the recorded cases.
The clinical study was undertaken on 24 poor risk patients out of 69 cases with hemorrhagic cerebral arteriovenous malformations, AVMs, and the surgical problems of poor risk patients with the lesions were discussed. The 24 cases, 35%, out of 69 hemorrhagic AVMs cases showed disturbances of consciousness of 3 digits (100-300) according to the Japan Coma Scale at the time of admission. All cases of these poor risk patients were observed less than 24 hours after the onset of the symptoms. Fifteen of these 24 cases showed brainstem signs including anisocoria and/or decerebrate rigidity and/or respiratory arrest. Eighty-three per cent of 24 poor risk patients had serious neurological defects as a result of the first hemorrhage. Therefore, it was impossible to prevent serious state from occurring in poor risk patients. Of the 69 cases with hemorrhagic AVMs, 56 cases were operated upon. Although 90% out of 38 good risk patients whose level of consciousness was 0 to 30 according to the Japan Coma Scale showed good recovery, only 44% of 18 poor risk patients recovered well. It could not be said that the surgical treatment gave satisfactory results for the poor risk patients when compared with the surgical results of the good risk patients. In respect to the location of AVMs, all three poor risk patients with AVMs in the corpus callosum and the ventricles showed good recovery, whereas of the poor risk patients with AVMs in the cerebrum or the cerebellum, only 4 out of 9 cases (44%) and 1 out of 6 cases (17%) showed good recovery respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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We studied two familial cases of human T-lymphotropic virus type I (HTLV-I)-associated myelopathy from the Kii Peninsula, an area of endemic adult T-cell leukemia-lymphoma (ATLL) in Japan. Incidence of familial clustering of HTLV-I-associated myelopathy was about 20%. Type C retrovirus was isolated from cultured cerebrospinal fluid and peripheral blood lymphocytes in both cases. Modes of transmission seem to be similar to those described in ATLL, although there are no reports of both HTLV-I-associated myelopathy and ATLL occurring in the same family. We suggest three possibilities: (1) that the virus associated with HTLV-I-associated myelopathy is different from the virus causing ATLL, although they seem to be morphologically and immunologically similar; (2) that HTLV-I-associated myelopathy may be determined by the ATLL-causing virus plus a specific genetic background; and (3) some combination of factors 1 and 2.
Plasma levels of atrial natriuretic peptide (ANP) were measured in 32 untreated subjects with essential hypertension and in 31 patients undergoing long-term treatment with beta-blockers. Patients receiving beta-blockers had significantly higher mean plasma ANP levels (72.0 +/- 36.0 [SD] pg/ml) than did untreated hypertensive subjects (39.8 +/- 15.8 pg/ml; p less than 0.01) and healthy normotensive controls (33.9 +/- 16.6 pg/ml; n = 61, p less than 0.01), while the mean plasma ANP concentration in untreated hypertensive subjects was not statistically different from that in control subjects. Administration of atenolol, 50 mg/day, for 4 weeks to 10 untreated subjects resulted in a significant (p less than 0.001) rise in plasma ANP levels (from 38.8 +/- 9.5 to 68.7 +/- 20.6 pg/ml). In 31 patients undergoing long-term treatment with beta-blockers, multivariate regression analysis revealed that age, pretreatment mean blood pressure, and plasma concentration of cyclic 3',5'-guanosine monophosphate (cGMP) were significant predictors of plasma ANP levels. These results suggest that beta-adrenergic receptor blockade in patients with essential hypertension elevates plasma ANP levels with a concomitant rise in cGMP concentrations, and that increased ANP in plasma may play a role in the compensatory mechanism that operates in response to beta-adrenergic receptor blockade.