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Y Chiba

Publications and source records attributed to Y Chiba.

At least 217 records · Page 12Linked to original sources
PubMed1991

[A case of fibrous dysplasia (McCune Albright syndrome) associated with acromegaly].

We report a case of a 47-year-old woman with McCune-Albright syndrome associated with unusual growth-hormone and prolactin hypersecretion. Acromegaly was suspected on clinical examination, and she was referred to us. She had no history of precocious puberty or pathological fracture. She was 154cm tall, weighing 62kg with so-called acromegalic facies. There were two lumps, one of which was on her right lateral forehead. The other on the right lower extremity seemed to be due to a bone deformity. Some brown pigmented macules with irregular borders were present on her lips and oral mucosa. Endocrine examination revealed elevated basal levels of plasma GH (54ng/ml) and PRL (36.2ng/ml), which paradoxically increased after injection of TRH. Plasma levels of these hormones did not change after LHRH test, and plasma GH level increased after GHRH test. A skull X-ray film showed a double floor of the sella turcia and hyperostotic formation of the right sphenoid bone. MRI and CT showed a tumor shadow in the right sella turcica. Bone roentogenography of the right fibula and tibia showed a large centrally expanding lesion with a ground-glass or cystic appearance and a thin cortex. The left fibula showed a similar lesion. We recognized similar findings in other bones which also showed abnormal accumulation in a radionuclide bone scan with 99mTc. On the basis of physical, endocrinological and roentogenographical examination, we diagnosed her as displaying McCune-Albright syndrome. We operated on her by transsphenoidal surgery and confirmed a functioning chromophobe adenoma which was removed during surgery. She has been free of GH and PRL hypersecretion since then. The pathology of the sphenoidal sinus affected with fibrous bone was in accordance with the findings of fibrous dysplasia. McCune-Albright syndrome (MCAS) is known as a syndrome characterized by polyostotic fibrous dysplasia and cutaneous pigmentation and multiple endocrinopathy. Its etiology is unknown. This syndrome with acromegaly is rare, and although 26 cases have been described in literature, pathological examinations have been undertaken in only three cases. This case was very rare and valuable because, by operating on her by the transsphenoidal route in spite of the sphenoidal sinus being affected with fibrous bone, we were able to confirm a chromophobe adenoma secreting both GH and PRL. We recognized that acromegaly with MCAS was endocrinologically, morphologically and immunohistologically the same as acromegaly without MCAS. Therefore, we concluded that acromegaly with MCAS is much the same as acromegaly without MCAS.

Acromegaly↗
PubMed1991

Effect of acetylpolyamines on in vitro protein synthesis and on the growth of a polyamine-requiring mutant of Escherichia coli.

The functions of acetylpolyamines were examined with respect to stimulation of protein synthesis and cell growth. Unlike polyamines, acetylpolyamines could not lower the optimal Mg2+ concentration of protein synthesis, and the degree of stimulation of protein synthesis by acetylpolyamines was small. The addition of N1-acetylspermine did not stimulate cell growth of a polyamine-requiring mutant of Escherichia coli MA261, although acetylspermine was accumulated in the cells. Acetylspermine did not interfere with polyamine stimulation of protein synthesis and cell growth of E. coli MA261. The binding of acetylpolyamines to RNA was very weak, and the binding of polyamines to RNA was not disturbed significantly by the presence of acetylpolyamines. When the growth of E. coli MA261 was stimulated by addition of polyamines, significant amounts of acetylpolyamines were also formed in the cells. These results suggest that acetylation of polyamines, together with polyamine excretion, may regulate the intracellular level of the parent polyamines when excess amounts of polyamines accumulate intracellularly.

Acetylation↗
PubMed1991

Optimum position for an anti-siphon device in a cerebrospinal fluid shunt system.

The effects on shunt flow from the position of an antisiphon device (ASD) and from changes in posture in hydrocephalic patients were examined. Fifty patients with hydrocephalus (including 36 with normal pressure hydrocephalus) were investigated, using quantitative radionuclide shuntography (99mtechnetium-pertechnetate) in the supine, sitting, and standing positions. The types of shunt valve used were as follows: Mishler dual chamber low pressure without ASD (16 cases), with ASD 40 cm below the level of the foramen of Monro (three cases), and with ASD 10 cm below the level of the foramen of Monro (12 cases); low pressure with integral ASD (14 cases); and medium pressure with integral ASD (five cases). In patients with a low pressure valve without ASD, shunt flow was least in the supine position (0.0011 ml/min) but increased significantly in the sitting position (0.4381 ml/min, P less than 0.001) because of the siphon effect. Conversely, in patients with a low pressure valve with integral ASD, shunt flow was maximal in the supine position (0.1056 ml/min) and decreased significantly in the sitting position (0.0017 ml/min, P less than 0.001), indicating overfunction of the ASD. Intracranial pressure (ICP) in the supine position increased significantly compared with patients with a low pressure valve without ASD (93.6 and 20.7 mm H2O, respectively, P less than 0.01). Intermediate values for shunt flow in the supine and sitting positions (0.0279 and 0.0896 ml/min, respectively) and for ICP (55.8 mm H2O) were obtained with patients with a low pressure valve with the ASD 10 cm below the level of the foramen of Monro (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Improvement of dissolution and bioavailability for mebendazole, an agent for human echinococcosis, by preparing solid dispersion with polyethylene glycol.

The solid dispersion of mebendazole was prepared with polyethylene glycol (PEG) to enhance the dissolution rate of mebendazole, an agent for the chemotherapy of human echinococcosis. The dissolution rate of the solid dispersion increased compared with the physical mixture, and also increased with the incorporation of an increasing amount of PEG-6000. An extensive improvement of the dissolution rate was observed when the ratio of the solid dispersion of mebendazole to PEG-6000 was more than 1: 2. Furthermore, greater bioavailability in rabbits was obtained after oral administration of the solid dispersion compared with the physical mixture.

Animals↗
PubMed1991

Subarachnoid dissemination of pineal germinoma 9 years after radiation therapy without local relapse--case report.

A 22-year-old female developed intracranial and spinal subarachnoid metastases 9 years after radiation therapy for a pineal germinoma. Computed tomographic scans showed no evidence of local recurrence. Cerebrospinal axis irradiation achieved total remission. Delayed subarachnoid dissemination may be caused by germinoma cells remaining dormant in the subarachnoid space, outside the radiation field.

Brain Neoplasms↗
PubMed1991

[Application of fuzzy theory for optokinetic pattern test].

The optokinetic pattern test for optokinetic nystagmus is performed to diagnose equilibrium disorders on clinical examination. We constructed computer assisted instruction (CAI) algorithm based on knowledge of expert for optokinetic pattern (OKP) diagnosis theoretically based Fuzzy reasoning derived from Fuzzy theory to ascertain the possible application of CAI to OKP and to develop a useful diagnostic tool. The algorithm was constructed by rules of fuzzy reasoning using analysed data of diagnostic modes of one expert, consisting of six variables, and of 30 normal and 22 abnormal patterns of optokinetic nystagmus which were diagnosed by the expert. The results derived from the fuzzy reasoning and those obtained by expert agreed with 96% in this test battery. In addition, a consistency of 87.3% was obtained after comparison with another 251 OKP patterns which diagnosed by the same expert and estimated by this algorithm. This algorithm incorporating fuzzy theory is concluded to be useful in obtaining results of the same as those of an expert for diagnosing the equilibrium disorders. Furthermore, CAI using Fuzzy theory is confirmed to have good potential as a diagnostic tools.

Algorithms↗
PubMed1991

[A phase II study of SM-5887 for advanced gastric cancer].

A phase II clinical trial of SM-5887, a new totally synthesized anthracycline derivative, was carried out in 13 patients with inoperable or recurrent gastric cancer. No patient had been given anthracycline previously. SM-5887 was administered by I.V. bolus with a dose of 100 mg/m2 every three weeks. Twelve of 13 cases were eligible and evaluable for the response. Of the 12 evaluated cases, 6 showed no change (NC), including one minor response (MR). The remaining 6 cases showed progressive disease (PD). Adverse effects were relatively mild in most cases and included anemia, leukocytopenia, thrombocytopenia, nausea/vomiting, phlebitis, hair loss and fever. Among them, leukocytopenia was observed most frequently.

Adenocarcinoma↗
PubMed1991

Effects of the new antiallergic drug epinastine and ketotifen on repeated antigen challenge-induced airway hyperresponsiveness in rats.

Airway hyperresponsiveness (AHR) is a critical component in bronchial asthma, probably associated with airway inflammation. The effects of epinastine (WAL-801 CL, CAS 80012-43-7), a new antiallergic drug, and ketotifen on AHR were investigated with a new AHR model in rats. Male Wistar rats which were actively sensitized with DNP-Ascaris (DNP-Asc) antigen, were challenged by inhaling DNP-Asc 3 times every 48 h. The airway responsiveness to inhaled ACh was determined 24 h after the last antigen challenge by modified Konzett-Rössler method under anesthesia with urethane. Antiallergic drugs were given orally 1 h before each antigen challenge in case of single treatment, and 3 times a day for 5 days in case of chronic treatment. The airway responsiveness to inhaled ACh was significantly increased after the repeated antigen challenge. Single treatments with epinastine and ketotifen did not inhibit AHR induced by repeated antigen challenge. On the other hand, chronic epinastine and ketotifen treatments, significantly inhibited the enhancement of AHR. From the above results, it is suggested that chronic treatments with epinastine and ketotifen are effective even for therapy of AHR.

Acetylcholine↗
PubMed1991

[Orthostatic purpura: report of two cases].

Two patients with orthostatic purpura were reported. Case 1: A 47-year-old man was admitted to our institution because of multiple purpuric eruptions over the legs after the long periods of sitting or standing. Bleeding time was 4.0 min. Platelet aggregation induced by ADP was disaggregated and no aggregation was observed when induced by collagen and epinephrine. He was diagnosed as having release abnormality of the platelets caused by glutathione administered for treatment of liver damage for several years. Purpura, however, appeared even though platelet function became normal after discontinuing glutathione. Purpura proved to be induced by the long periods of sitting or standing. Case 2: A 37-year-old woman was admitted to our hospital because of purpuric eruptions over the legs for three years. Bleeding time was 2.0 min. Platelet aggregation induced by ADP, epinephrine, collagen and ristocetin was normal. Purpura was caused by long periods of standing without movement. Wearing elastic pantyhose showed reduced appearance of the purpura. Biopsy specimens from both patients revealed no abnormal findings. Both patients had no abnormal results in coagulation studies. Purpura seemed to be caused by the increased capillary pressure after the prolonged periods of standing. No case report concerning orthostatic purpura or mechanical purpura has been published.

Adult↗
PubMed1991

[Continuous measurement of coronary sinus oxygen saturation in patients with effort angina and vasospastic angina].

Coronary sinus oxygen saturation (CSO2-Sat) was measured continuously using a fiberoptic catheter system during interventional catheterization, i.e., pacing stress test and ergonovine provocation test to determine whether such measurement can detect myocardial ischemia. Subjects consisted of 24 patients who underwent routine cardiac catheterization; 14 patients with effort angina, 3 with old myocardial infarction and 3 with valvular heart disease were assigned to pacing stress test, and 4 with vasospastic angina were assigned to ergonovine provocation test. The results were as follows: 1. Among 14 patients with effort angina, ischemic electrocardiographic changes occurred in 10 patients during pacing stress test. Of these 10 patients, CSO2-Sat decreased in 8 with ischemic electrocardiographic changes. All patients with decrease in CSO2-Sat had significant left coronary artery stenosis. CSO2-Sat continued to decrease throughout intervention and never came back to the baseline. Decrease in CSO2-Sat was more than 5% in most of the cases. 2. In all patients with vasospastic angina, coronary vasospasm was induced by the ergonovine provocation test. CSO2-Sat declined (> 5%) gradually, preceding anginal pain and ischemic ST segment changes. The present study suggests that continuous monitoring of coronary sinus oxygen saturation may be useful in detecting myocardial ischemia at its early stage, except for patients with right coronary artery disease.

Adolescent↗
PubMed1991

[Biological specificity of the neonate and infant heart, with reference to selenium and glutathione peroxidase--the study to clarify the cause of vulnerability of neonate and infant heart].

Selenium (Se) is known to be an integral part in glutathione peroxidase (GSHPx). There are some reports serum Se levels are lower in infants than in adults and GSHPx activity is parallel to Se levels. There may be reasons why myocardial reperfusion injury occurs more easily in infants than in adults by reperfusion of ischemic myocardium. Serum and myocardial Se levels and GSHPx activity in experimental rats were measured to clarify the vulnerability of infant heart. Wistar rats were divided into three groups. First, infant rats 8-12 days after birth (infant rats), second, adult rats fed Se-deficient diet for two months (Se-deficient rats), and third, adult rats fed normal diet for two months (control rats). Serum Se levels, serum GSHPx activity and myocardial GSHPx activity in both infant and Se-deficient rats were significantly lower than that in control rats (p less than 0.01). However myocardial Se levels in infant rats were significantly higher than that in both Se-deficient and control rats (p less than 0.01). The lipid peroxide levels in heart mitochondria of Se-deficient rats were significantly higher than that in control rats (p less than 0.01). These results suggest that in infant heart Se does not manifest an effective function for a integral part of GSHPx despite its high level, its reason is not clear, and this phenomenon generates more oxygen-derived free radicals after reoxygeneration of the ischemic myocardium.

Animals↗
PubMed1991

[Traumatic carotid-cavernous fistula presenting subarachnoid hemorrhage 5 years after head injury; case report].

A case of traumatic carotid-cavernous fistula (CCF) which presented subarachnoid hemorrhage long after the injury is reported. A 24-year-old male was admitted to the National Yokohama Hospital with complaints of severe headache and nausea. CT scan and cerebral angiography showed subarachnoid hemorrhage due to ruptured CCF. His right visual acuity has disappeared after a traffic accident 5 years before, and he had hit his forehead again 3 years previously. He experienced severe headache twice for 2 weeks after his admission. He was transferred to Kanagawa Rehabilitation Center to be treated with intravascular surgery. Plain CT showed high density areas in the basal cisterns. CT after contrast infusion disclosed a small enlarged high density area in the right cavernous sinus, and showed an enhanced mass lesion in contact with the right ventrolateral side of the midpons. The right internal carotid angiogram showed high flow CCF, fed only by the internal carotid artery. It drained mainly into the basilar plexus, partially into the basal vein of Rosenthal and the inferior petrosal sinus. The CCF was found at the C4 portion of the right internal carotid artery. CT and the angiogram revealed a part of the CCF developing into a varix in the ventral side of the prepontine cistern. It ruptured and the patient developed subarachnoid hemorrhage 5 years after the head injury. The CCF was intravascularly embolized by a detachable balloon. Early treatment for CCF is necessary to prevent the occurrence of subarachnoid hemorrhage if a part of the CCF develops into a varix.

Adult↗
PubMed1991

[Early operation of ventricular septal rupture complicating acute myocardial infarction].

Four patients underwent successful early operation for post-infarction ventricular septal rupture. The periods from the onset of the rupture to operation were 19.5 hours, 13 hours, 7 hours and 8 days. In early operation, it has generally been thought that the fragility of the myocardium makes the operative technique difficult. With our experience of four cases, it was not difficult to distinguish the infarcted area from the viable one. To perform the successful early operation, it is important to suture at the viable muscle after complete excision of the infarcted muscle, and a patch for ventricular septum and when necessary, for a left ventricular free wall should be used to maintain the left ventricular volume.

Aged↗
PubMed1991

[Significance of selenium deficiency on myocardial protection of the mature and immature rat hearts].

A trace element selenium (Se) is an integral component of glutathione peroxidase (GSHPx) which is one of the important free radical scavenger. We previously reported that serum Se level and serum and myocardial GSHPx activities were significantly lower in infant rats than adult ones. Exactly the same conditions were made by feeding Se-deficient diet for 8 weeks in Wistar rats. Vulnerability to ischemic injury was tested using these Se-deficient rats. Wistar rats fed a commercial laboratory ration were used as a control. Isolated hearts were perfused aerobically with Krebs-Henseleit solution in the Langendorff mode for 15 minutes followed by coronary perfusion with St. Thomas Hospital cardioplegic solution. The hearts were subjected to 60 minutes global ischemia at 4 degrees C. The hearts were reperfused for 30 minutes in working mode, and aortic pressure, LV pressure, LV max dp/dt, coronary flow and aortic flow were measured. In Se-deficient rats aortic pressure (58.5 +/- 1.9 versus 77.3 +/- 8.5 mmHg, p less than 0.01), LV max dp/dt (2023 +/- 153 versus 2722 +/- 513 mmHg/sec, p less than 0.05), aortic flow (8.7 +/- 2.7 versus 17.0 +/- 2.5 ml/g wet wt., p less than 0.01), cardiac output (17.0 +/- 4.6 versus 24.6 +/- 2.0 ml/g wet wt., p less than 0.05) and stroke volume (67.5 +/- 11.6 versus 95.6 +/- 9.8 microliters/g wet wt., p less than 0.01) were significantly inferior to control rats. Then the hearts were iced instantly by fluid nitrogen and myocardial thiobarbituric acid reactive substance (TBARS) level was measured.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Differing susceptibilities to cold preservation of rat atria and ventricles.

The susceptibilities of atria and ventricles to cold preservation were studied in rat hearts. Rat hearts were stored in Collins' solution at 4 degrees C for 0, 12, or 24 hours, and the atrial and ventricular function was measured in a working heart model and in isolated atrial and papillary muscle preparations. In working heart preparations, cardiac output decreased to 0 ml/min and other parameters of ventricular function (systolic and end-diastolic pressure and dP/dt of the left ventricle) markedly deteriorated after 12 hours of preservation. After 24 hours, no contraction of the left ventricle was observed despite the presence of atrial contraction. In isolated atrial muscle preparations, the rate of spontaneous beating of the right atrium was not affected by cold preservation. The twitch contractions of right and left atria were attenuated but elicited after 24 hours. In electrically driven papillary muscles, twitch contractions were also markedly attenuated by 12 hours of preservation and were abolished after 24 hours. The positive inotropic effect of isoproterenol was also markedly attenuated in the atrial preparations by cold preservation. However, the positive chronotropic response to isoproterenol and the negative chronotropic and inotropic responses to carbachol were little affected by cold preservation. Intramural cholinergic and adrenergic nerve stimulation produced first negative and then positive effects on the beating rate and twitch contraction in the isolated right atria. Cold preservation selectively attenuated and finally abolished the adrenergic responses. In the ventricles, the adenosine triphosphate and creatine phosphate content significantly decreased and the lactate content increased with an increase in the preservation period. On the other hand, changes of such metabolites in the atria were either not observed or were much smaller. These results suggest that atrial function is maintained better than ventricular function in the cold-preserved heart.

Animals↗