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Biomedical subjects

Y Hashimoto

Publications and source records attributed to Y Hashimoto.

At least 1,189 records · Page 66Linked to original sources
PubMed1989

Autoregulation of renal blood flow in streptozocin-induced diabetic rats.

Autoregulation of renal blood flow (RBF) was studied in male Wistar rats. We studied 11 control rats, 11 rats with severe streptozocin (STZ)-induced hyperglycemia (diabetic group), and 10 moderately hyperglycemic rats made diabetic by injection of STZ but given 2-8 U s.c. insulin daily (insulin-treated group). RBF was measured by an electromagnetic flowmeter during stepwise reduction of renal perfusion pressure 4-8 wk after injection of STZ (older group). RBF autoregulation of the diabetic group was impaired compared with the control group. In the insulin-treated group, autoregulatory capability was less attenuated than in the diabetic group. The average autoregulatory index (ARI) of the diabetic group (0.61 +/- 0.05) was greater than that of the control (0.24 +/- 0.02, P less than .01) and the insulin-treated (0.33 +/- 0.07, P less than .05) groups. To study the relationship between autoregulation and the duration of diabetes, an autoregulatory study was also made in a group of 22 rats (11 diabetic and 11 control) that were tested 2-3 wk after injection of STZ (younger group). The ARI in the younger diabetic group was smaller than that in the older diabetic group (P less than .05). The results suggest that in uncontrolled diabetes RBF fluctuates with blood pressure change, and protection against hypertensive injury of glomerular capillaries may be diminished. Autoregulatory disability develops with time, and insulin treatment diminishes impairment of autoregulation. These findings may also explain the adverse consequences of hypertension on the progression of diabetic nephropathy in poorly controlled diabetes.

Animals↗
PubMed1989

Inhibitory effect of peptide YY on gastric acid output in rats.

The administration of peptide YY (PYY: 0.8, 1.6 and 3.2 nmol/kg/h, i.v.) to fasting rats inhibited not only baclofen (2 mg/kg, s.c.)-stimulated gastric acid output and gastric mucosal blood flow, but also pentagastrin (8 micrograms/kg/h, i.v.)-stimulated gastric acid output. PYY (3.2 nmol/kg/h) reduced baclofen-induced acid output more than pentagastrin-induced acid output, i.e., by 61.8 +/- 11.5% compared to 35.3 +/- 8.2%. PYY inhibited acetylcholine (ACh) release from cholinergic nerve endings of gastric body evoked by electrical transmural stimulation (ETS: 1 msec, 10 V, 3 Hz, 30 sec) by 47.2 +/- 3.5%. The mechanism of the inhibitory effect of PYY on gastric acid output seems to involve decreased gastric mucosal blood flow and reduced ACh release from cholinergic nerves.

Animals↗
PubMed1989

The mechanism of acute gastric ulcer after induced hemorrhagic shock.

Changes in gastric mucosal blood flow were investigated for their relationship to gastric mucosal prostaglandin E2 (PGE2) and noradrenaline (NA) in rats with hemorrhagic shock. The results were as follows: 1) Gastric mucosal blood flow and NA decreased after hemorrhage. Gastric mucosal PGE2 initially increased after exsanguination and then markedly decreased. 2) Administration of NA before hemorrhage resulted in an increase of PGE2. However, the PGE2 value for animals receiving NA after hemorrhage was not different from that of non-NA-treated group. 3) Pre-treatment with PGE2 suppressed the reduction in both gastric mucosal blood flow and NA and the development of ulcer. These results suggest that the increase in gastric mucosal PGE2 in the early stage of shock might represent a phenomenon of adaptation by the adrenergic activation, and the decrease in PGE2 in the late stage might result from impaired synthesis of PGE2 due to persistent hypoxia and might be one of the possible factors in ulcer formation.

Acute Disease↗
PubMed1989

Histological study on seminal plasma absorption and spermiophagy in the epididymal region of domestic fowl.

Absorption of seminal plasma and spermiophagy in the fowl epididymal region were studied ultrastructurally and histochemically. Epithelial cells of the rete testis had sparse coated vesicles and rarely showed spermiophagy. Many macrophages in the lumen of the rete testis actively phagocytosed spermatozoa. Nonciliated cells in the proximal efferent ductules had well-developed microvilli, coated vesicles, numerous tubular structures, and lysosomes in their apical cytoplasm. They rarely contained fragments of spermatozoa. Intense alkaline phosphatase activity was observed at the luminal borders of these cells. Ciliated cells had no features indicating active absorption of seminal plasma. Epithelial cells of the connecting ductules and epididymal duct had numerous microvilli, a few vesicles, and small lysosomes. They did not contain spermatozoa. Intense acid phosphatase activity was observed on the luminal and lateral surfaces of the epithelial cells of the connecting ductules and epididymal duct. After injection of horseradish peroxidase into the excurrent ducts, a large amount of reaction product was detected in the vesicles and tubular structures of the nonciliated cells of the proximal efferent ductules. These results suggest that the absorption of seminal plasma occurred mainly in the efferent ductules, and that spermiophagy by macrophages occurred in the rete testis in the fowl epididymal region.

Absorption↗
PubMed1989

Thrombolytic properties of human tissue-type plasminogen activator, single-chain urokinase-type plasminogen activator, and synergistic combinations in venous thrombosis models in dogs and rabbits.

Thrombolysis with single and combined four-hour intravenous (IV) infusions of recombinant tissue-type plasminogen activator (rt-PA), recombinant single-chain urokinase-type plasminogen activator of 54,000 molecular weight (mol wt) (rscu-PA), and rscu-PA-32 kD, an rscu-PA derivative of 32,000 mol wt was studied in a femoral vein thrombosis model in the dog and in a jugular vein thrombosis model in the rabbit. In both species, the dose-response curves were linear, and no systemic activation of the fibrinolytic system or fibrinogen breakdown was observed. The steady-state levels of rt-PA-, rscu-PA-, and rscu-PA-32 kD-related antigens in plasma were proportional to the infusion rates. In the dog model, 25% lysis was obtained with 0.11 mg/kg rt-PA, 0.8 mg/kg rscu-PA, and 0.37 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA were 2.6 times more active (P less than .005) than anticipated on the basis of their pharmacologic additive effects, whereas combinations of rt-PA and rscu-PA-32 kD were 2.7 times more active (P less than .05). In the rabbit model, 25% lysis was obtained with 0.24 mg/kg rt-PA, 0.75 mg/kg rscu-PA, and 1.25 mg/kg rscu-PA-32 kD. Combinations of rt-PA and rscu-PA have a fivefold synergistic interaction, but surprisingly no synergism was observed between rt-PA and rscu-PA-32 kD. This study shows that synergism between rt-PA and rscu-PA occurs both in rabbits and dogs in a relatively narrow concentration range that allows a fractional reduction of the total equipotent dose by a factor of 2.5-fold to fivefold. Combination therapy is not associated with systemic fibrinolytic activation. This range of synergistic interaction, although limited, may be useful in devising the best thrombolytic therapy for patients with thromboembolic disease.

Animals↗
PubMed1989

[Limb-saving surgery of malignant bone tumors using massive bone grafts].

The artificial materials in limb-saving surgery pose problems such as the age of patient, tolerance and stability. Thus, massive bone grafting should be reconsidered. In our clinic, out of 78 patients having malignant bone tumors, 29 received limb-saving surgery, and 10 of these cases received massive bone grafting using autografts and/or frozen allografts between 1968 and 1987. There were 7 cases with osteosarcoma, 1 case with mesenchymal chondrosarcoma, 1 case with leiomyosarcoma and 1 case with malignant fibrous histiocytoma. There were 5 males and 5 females ranging in age from 11 years to 44 years, and averaging 21 years. According to Enneking's staging system, these were all II-B cases. The median follow-up period was 71 mos, ranging from 13 to 239 mos. According to the modified Amago evaluation method, 80% of these cases had an excellent prognosis, one had a recurrence, but in all cases good bone union and stability were achieved without immunological reaction. Therefore we conclude that massive bone grafts in cases of malignant bone tumor surgery is a very beneficial method.

Adolescent↗
PubMed1989

[Adriamycin, cisplatin, and etoposide combination chemotherapy for small cell lung cancer].

Twenty-three patients with small cell lung cancer (11 with limited disease and 12 with extensive disease) who had not received previous chemotherapy were treated with a combination of adriamycin (30 mg/m2, i.v., on day 1), cisplatin (80 mg/m2, i.v., on day 1) and etoposide (70 mg/m2, i.v., on day 1-5). This chemotherapy regimen was repeated at 3- or 4-week intervals for 3 to 5 treatment cycles. Among 22 evaluable patients, 5 showed complete response and 17 had a partial response (response rate 100%). The median response duration of 12 extensive disease patients was 21 months. There were 5 survivors for more than 2 years. Toxicity included moderate to severe hematologic toxicity, alopecia, nausea and vomiting. This combination chemotherapy appears to be optimal for the treatment of small cell lung cancer.

Aged↗
PubMed1989

[Peripheral neuropathy caused by cisplatin in patients with lung cancer].

The correlation between peripheral neuropathy and cisplatin (CDDP) was elucidated in 27 patients with primary and metastatic lung cancer, who were treated with Adriamycin 30 mg/m2 day 1, CDDP 80 mg/m2 day 1, and VP-16 70 mg/m2 day 1-5 every 4 weeks. The incidence of peripheral neuropathy was 33% (9 of 27 patients) and it increased to 60% in the patients who received over 320 mg/m2 of CDDP, demonstrating a positive correlation between the incidence of this toxicity and the total dose of CDDP. However, no significant relation was observed between the grade of neuropathy and CDDP. The neuropathy was manifested in the sensory system of the distal extremities and was developed into proximal portions. The peripheral neuropathy with grade 3 was irreversible, resulting in the dose-limiting factor of this regimen.

Adult↗
PubMed1989

Effect of black-pigmented Bacteroides gingivalis on cytotoxic activity of linolenic acid against mouse macrophages.

The effects of sonicates of black-pigmented Bacteroides gingivalis (Bg-sonicates) on the cytotoxicity of linolenic acid (LA) against mouse macrophages were examined. Treatment of macrophages with LA alone or in combination with Bg-sonicates resulted in the release of lactate dehydrogenase (LDH) from the cells. This observation suggests the cytotoxicity of LA. Also, an increase in thiobarbituric acid-reactive materials was observed in experimental systems of the addition of Bg-sonicates to LA. The cytoplasm of macrophages treated with LA was not stained with May-Grünwald-Giemsa solution, while neither the nucleus nor the cytoplasm was stained when the cells were treated with LA and Bg-sonicates. The above cytotoxicity was nearly abolished when LA and Bg-sonicates were preincubated before the addition to macrophages. B. gingivalis is considered to increase the extent of the cytotoxic effects of LA to the cell nucleus by promoting peroxidation of LA.

Animals↗
PubMed1989

[A case of ischemic oculopathy followed by border zone infarction].

We reported a 72-year-old male with ischemic oculopathy due to ophthalmic artery stenosis followed by ipsilateral border zone infarction due to internal carotid artery stenosis. The patient had history of hypertension and diabetes mellitus. He had severe headache and visual disturbance of the right eye. He was diagnosed right neovascular glaucoma and left diabetic retinopathy (simple type), and received diuretics, beta-blockade and other anti-hypertensive drugs. One month later, he noticed left mild hemiparesis in a morning, and he experienced progression of left hemiparesis over a week. He was admitted to our hospital on the 11th day. He showed left complete hemiplegia, left sensory disturbance, anosognosia and left unilateral spatial neglect. His right eye was diagnosed neovascular glaucoma but left eye was normal. The 5th days CT showed low density area in the right terminal zone and bilateral periventricular lucency. At the same area, the 46th days MRI showed high intensity area in the T2-weighted image and low intensity area in the T1-weighted image. Cerebral angiography performed on the 33rd day, disclosed severe kinking at the cervical segment and 50% stenosis at the intracavernous segment in the right internal carotid artery, and 90% stenosis and post-stenotic dilatation of the right ophthalmic artery. Left internal carotid artery had each 60% stenosis at the cervical segment and the intracavernous segment. Left ophthalmic artery had severe stenosis from its beginning to distal part. This infarction was considered berder zone infarction by it's localization (terminal zone) and internal carotid artery stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Long-term effects of phenobarbital on rat liver microsomal drug-metabolizing enzymes and heme-metabolizing enzyme.

Long-term effects of phenobarbital on changes of rat hepatic enzymes involved in drug and heme metabolism were examined by employing two different treatment schedules which produce tolerance (tolerant group) and/or dependence (dependent group) against the drug. In both treatment groups, phenobarbital produced a marked and persistent induction of cytochrome P-450 and aminopyrine N-demethylase; the response was greater in the tolerant group than that in the dependent group at the early time periods. Thereafter, the magnitude of the induction of drug-metabolizing enzymes gradually decreased and finally was maintained at two-fold of the corresponding control levels. Likewise, the induction of cytochrome P-450b+e content, one of the major phenobarbital inducible species, was maintained at 40% of the total cytochrome P-450 content. Phenobarbital treatment resulted in increase of delta-aminolevulinate synthetase (ALAS) activity and a decrease in heme oxygenase (HO) activity. Changes of these enzymes involved in heme metabolism coincided with changes of the drug-metabolizing enzymes. Finally, the changes of enzyme content and activity after terminating phenobarbital treatment were determined and enzyme biological half-lives were calculated employing protein synthesis inhibitors. No significant differences in the changes of cytochrome P-450 and cytochrome P-450b+e content between the groups were observed after terminating phenobarbital treatment. However, changes of ALAS and HO activities after terminating the drug were significantly different between the groups; changes in the dependent group corresponded to the decrease in serum phenobarbital levels. On the other hand, biological half-lives of microsomal drug-metabolizing enzymes were longer in the tolerant group than in the dependent group.

5-Aminolevulinate Synthetase↗
PubMed1989

[A case of ischemic disturbance of inner ear].

We reported a 51-year-old male with ischemic disturbance of right inner ear resembling Meniere's disease. The patient had a sudden-onset episode of vertigo, right severe hearing disturbance, nausea, vomiting and gait disturbance. Two days after, he had hypersomnia, vertical gaze palsy, double vision, left Horner's sign, and sensory disturbance of pain and temperature of right half body involving face. Brain MRI disclosed high intensity area in T2-weighted image and proton density in bilateral paramedian thalamo-mesencephalic region and right cerebellum (area of the anterior inferior cerebellar artery). Cerebral angiography showed 90% or more stenosis of the right vertebral artery, 50% stenosis of the left vertebral artery before the posterior inferior cerebellar artery (PICA), and 60% stenosis of distal portion of the basilar artery. Furthermore, stem portion of the posterior cerebral artery, and the right anterior cerebellar artery and the left vertebral artery after the PICA were absent or occluded. Right deafness was evaluated to be Jerger type II, namely disturbance of inner ear. Caloric tests showed no response, and right auditory brainstem response showed no waves. Main cause of this vertigo and right deafness was considered to be disturbance of inner ear due to ischemia of right labyrinthine artery, though this patient was not a typical case of the anterior cerebellar artery syndrome. Ischemic disturbances of inner ear have been reported only in patients with the anterior cerebellar artery syndrome, therefore this patient who had only acute ischemic disturbance of inner ear and did not have disturbance of caudo-lateral portion of the pons was considered to be very rare.

Cerebral Angiography↗
PubMed1989

[Anesthesia for a patient with HELLP syndrome].

A case of 30 year-old female with HELLP syndrome, who had undergone emergency caesarean section under general anesthesia, was reported. HELLP syndrome is characterized by hemolysis, liver dysfunction and thrombocytopenia, besides symptoms of severe toxemia of pregnancy. After an awake orotracheal intubation, anesthesia was maintained with nitrous oxide, oxygen and muscle relaxant. Blood pressure was controlled with intravenous administration of nitroglycerin. Though the eclampsia was recognized several times during and after the operation, the patient and her baby had no complication nor sequela on their discharge. The key in the anesthetic management of caesarean section in a patient with HELLP syndrome is to control hypertension and eclampsia, to consider the presence of liver and kidney dysfunctions, and to improve anemia and bleeding tendency.

Adult↗
PubMed1989

[Palilalia associated with progressive supranuclear palsy].

Two cases of progressive supranuclear palsy (PSP) with palilalia were presented. Case 1: A 64-year-old woman was in good health until age 62 when she noted clumsiness in walking. Subsequently, forgetfulness, abrupt falls and difficulty in swallowing developed. At the age of 63, she tended to repeat same words in conversation. On admission, neurological examination revealed mental deterioration (Hasegawa's scale 19), unsteady emotional state, supranuclear vertical gaze palsy, pseudobulbar palsy, nuchal dystonia, pyramidal tract signs and extrapyramidal signs. Although spontaneous speech production was reduced, she could answer to questions with compulsive repetition of a phrase or word. She always repeated twice or three times without stuttering, logoclonus or "palilalie aphone". Case 2: A 68-year-old, right-handed woman noted double vision since about one year ago. Subsequently, she developed slowness of voluntary movement, forgetfulness and difficulty in walking. Neurological examination showed similar signs as Case 1. She was not palilaic on examination, however we found the description of her palilalia on nurse's working records. Palilalia was not present so constantly as Case 1, but continued for about a year. We suppose that palilalia is not a rare phenomenon in PSP. Although the pathogenesis of palilalia is unknown at present, we speculate the combination of extrapyramidal sign, pseudobulbar palsy and dementia may most contribute the pathogenesis of palilalia on PSP.

Aged↗
PubMed1989

[A case of medullary infarction presented lateral medullary syndrome and respiratory arrest after ataxic respiration].

We reported a 71-year-old male with lateral medullary syndrome presented acute respiratory arrest after ataxic respiration. The patient had experienced transient diplopia repeatedly for about 2 weeks and then the developed persistent diplopia and vertigo. On the third day he was admitted to our hospital because of neurological deterioration and aspiration pneumonia. He showed left Horner's sign and double vision. And he had sensory disturbances of pain and temperature in the left face and the right side of the body, left limb ataxia and truncal ataxia. He showed dysarthria, severe dysphagia and left mild central facial paresis, but no hemiparesis. This case was clinically considered to be a typical case of left lateral medullary syndrome. When he was admitted to our hospital, he showed hypoxia with hypercapnea in spite of no history of chronic obstructive pulmonary disease. This condition was considered to be a central alveolar hypoventilation. He had two episodes of sudden-onset respiratory arrest following ataxic respiration on the 4th and 5th days, but no cardiac arrest. He was supported his respiration by mechanical ventilation until he was able to breathe spontaneously on the 29th day. The 22nd day MRI disclosed high intensity area in the left lateral and dorso-medial medulla in T2-weighted image, and this lesion was 1.5 cm in length. Therefore this case was diagnosed medullary infarction. This case developed ipsilateral facial pain in chronic stage. Pain existed around the eye and in the cheek, and pain was like toothache and unbearable like thalamic pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

[Familial antithrombin III abnormality accompanied with progressing ischemic stroke].

We report a case of familial antithrombin III (AT-III) abnormality accompanied with progressing ischemic stroke. The patient was a 31-year-old female who developed consciousness disturbance and left hemiparesis on December 1 in 1987. She had a history of two transient ischemic attacks and three episodes of thrombophlebitis of the extremities. Cerebral CT scan showed a low density area on the right temporal lobe that had extended to the right parietal and on the left frontal lobe as clinical symptoms worsened. Cerebral angiogram revealed branch occlusions of the right middle cerebral artery and showed no cerebral venous and sinus obstruction. When her symptoms had been progressing to show semi-comatose state, left hemiplegia and transient Cheyne-Stokes respiration, we found her decreased biological activity and normal immunological level of AT-III. The diagnosis of familial AT-III abnormality had been made by familial investigation. As the treatment of AT-III concentrates transfusion was started from the third day, her symptoms gradually recovered and the low density area stopped extending. Further examinations revealed that she was a homozygote of AT-III abnormality presenting no affinity for heparin and that her parents were heterozygotes. It was suggested that the homozygous AT-III abnormality was the main cause of her progressing ischemic stroke.

Adult↗