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Biomedical subjects

H Nozaki

Publications and source records attributed to H Nozaki.

At least 19 recordsLinked to original sources

Development of the human pontine nuclei: a morphometric study.

The morphometric development of the pontine nuclei in the human fetus from 16 to 40 gestational weeks, in a 2-month-old infant and in a 63-year-old adult were examined employing a serial celloidin section method and computer assisted electronic planimeter. The results of our study can be summarized as follows: (1) the development of the human pontine nuclei accelerated in volume after 32 gestational weeks and continued after birth, (2) neuron numbers remained relatively constant after 27 gestational weeks. It was difficult to clearly distinguish neurons from glia before 27 gestational weeks. The total estimated neuronal numbers were not indicative of the gestational stages in infants 27 gestational weeks and older, (3) individual neurons appeared to continue to develop after 32 gestational weeks in accordance with size, distribution and circularity ratio, (4) many islet-shaped groups of large neurons appeared and were scattered throughout the pontine nuclei after 32 gestational weeks.

Cell Count

Alteration of second-messenger ligand binding following 2-hr hemispheric ischemia in the gerbil brain.

The alterations of second-messenger ligand binding and cerebral blood flow (CBF) were evaluated in the gerbil brain after 2-h unilateral common carotid artery occlusion. [3H]Forskolin (FK) and [3H]phorbol-12,13-dibutyrate (PDBu) were used as specific ligands for adenylate cyclase (AC) and protein kinase C (PKC) activity estimation, respectively. CBF was determined at the end of the experiment by the [14C]iodoantipyrine method. A quantitative autoradiographic method permitted simultaneous measurement of the three parameters in the same brain. The levels in the caudate-putamen, globus pallidus, and hippocampus were analyzed. The animals were divided into three groups: Group 1 with severe ischemia (CBF in the lateral nuclei of the thalamus (CBFt) less than 50 ml/100 g/min), Group 2 with mild ischemia (CBFt greater than or equal to 50 ml/100 g/min), and the Sham Group. The PDBu binding revealed a statistically significant increase in the caudate-putamen, lateral nuclei of the thalamus and hippocampus (CA1 and CA3 regions and dentate gyrus) on the ischemic side in Group 1 as compared to that in Group 2 and the Sham Group. In contrast, the FK binding did not show any significant changes in any of the regions. These data and our previous findings for 6-h ischemia suggest that (1) PKC translocation to the cell membrane may occur at the early ischemic phase in particular regions including the caudate-putamen, lateral nuclei of the thalamus and hippocampus, with the translocated PKC gradually diminishing during the subsequent ischemic period; and (2) the suppression of the AC system observed in 6-h ischemia may not appear in the early ischemic phase.

Adenylyl Cyclases

Anti-aids agents, 6. Salaspermic acid, an anti-HIV principle from Tripterygium wilfordii, and the structure-activity correlation with its related compounds.

Salaspermic acid [1], an inhibitor of HIV reverse transcriptase and HIV replication in H9 lymphocyte cells, was isolated from the roots of Tripterygium wilfordii for the first time. The structure of 1 derived from spectral data was established unequivocally by an X-ray analysis of crystals of the monohydrate. A structure-activity correlation of 1 with ten related compounds indicated that the acetal linkage in ring A and the carboxyl group in ring E of 1 may be required for the anti-HIV activity.

Antiviral Agents

[Experimental study on the effect of ursodeoxycholic acid in liver transplantation].

We investigated the effects of combination of cyclosporine A (CsA) and ursodeoxycholic acid (UDCA) in order to reduce hepatopathy caused by host-versus-graft-reaction (HVG reaction). DA/S1c rats were used as donors, and LEW/Sea rats were used as recipients in orthotopic liver transplantation. The liver transplanted rats were divided to four groups as follows; group A was control that was not given CsA nor UDCA, group B was given CsA alone, group C was given UDCA alone and group D was given combination of CsA and UDCA. These groups were compared and evaluated in case of same dose of CsA that was administered with or without UDCA. The survival periods of group D were significantly longer than those of group B. Blood biochemical levels in group D were significantly lower than those of group B. Histological study of the liver graft of group D showed that destruction of hepatic structure was mild in comparison to that of group B. It was demonstrated that the combination of low dose of CsA and UDCA could prevent hepatopathy due to HVG reaction. These results suggested that addition of UDCA to CsA would be able to reduce the dose of CsA in clinical liver transplantation.

Animals

[CT findings of six cases with intracranial tuberculosis in National Higashi-Saitama Hospital].

We have experienced 6 cases of intracranial tuberculosis since 1985. 2 cases were diagnosed as intracranial tuberculoma without tuberculous meningitis, and 4 cases were diagnosed as tuberculous meningitis. Brain CT showed intracranial tuberculomas in three of them, and showed cerebral infarcts in two cases, and showed hydrocephalus in two cases. Brain CT on intracranial tuberculosis showed various findings. In two cases with tuberculous meningitis, brain CT showed many tuberculomas with ringed or nodular enhancement appeared after adequate chemotherapy had been started. About 1 year later, a few tuberculomas were found with homogeneous enhancement and were enlarged while the chemotherapy was continued. But later they were reduced in size. The above facts may suggest that intracranial tuberculoma could appear and be enlarged on cranial CT in spite of adequate anti-tuberculous chemotherapy during a course of tuberculous meningitis. They also suggest that the continuation of adequate chemotherapy might be necessary to the treatment of intracranial tuberculomas.

Aged

[Paradoxical expansion of intracranial tuberculomas during chemotherapy].

A 45-year-old female patient was admitted to a hospital because of tuberculous meningitis in July, 1986. She was treated with chemotherapy (oral isoniazid, rifampicin, ethambutol and an intramuscular injection of streptomycin). Her consciousness was worsened at first, but later she improved aside from some disabilities (incontinence, gait disturbance, disorientation and dementia). She was transferred to National Higashisaitama Hospital in November, 1986. Since then we have continued the chemotherapy, and she has improved gradually. Initially her cranial computerized tomography (CT) revealed no intracranial tuberculoma and showed mild enhancement of basal cistern. About 4 months later, her CT showed many tuberculomas with ringed or nodular enhancement. About 13 months later almost all tuberculomas disappeared. But a few were found with homogeneous enhancement and were enlarged in spite of adequate chemotherapy. These tuberculomas were enlarged while the chemotherapy was continued, but later they were reduced in size. About 3 and a half years later, these tuberculomas disappeared without any calcifications. The above facts may suggest that intracranial tuberculoma could appear and be enlarged on cranial CT in spite of adequate chemotherapy during a course of tuberculous meningitis. They also suggest that continuation of adequate chemotherapy might improve tuberculomas.

Antitubercular Agents

[The appearance of "central core of respiratory muscle" in patients with respiratory failure].

We report the histological and histochemical features of core fibers present in respiratory muscles obtained from autopsy since 1980. Fifty autopsy cases of adults without neuromuscular disease were examined. "Central core" structure was present in 38 cases and absent in 12 cases. The duration of D.O.E. was greater than 1 month in 81.8% of core positive cases. In core negative cases, the duration of D.O.E. was less than 3 months. "Central core" structure were present in 80.0% of chronic respiratory failure cases and 41.7% of non-chronic cases. It is suggested that central core in respiratory muscles develops less than 3 months after the onset of D.O.E.

Adult

[A case of endometrioid carcinoma arising from endometriosis of the rectum].

A very rare case with rectal endometriosis heterotopic transformed into carcinoma is reported. A 44-year-old female patient underwent colostomy due to ileus. Postoperative examinations revealed submucosal tumors all around the rectum. Low anterior resection and the closure of the colostomy were performed. Thickening in the muscular layer and serosa were observed in the resected specimen, but the mucosal surface was maintained. Histopathological observation revealed glands of the endometrium and connective fibers with glandular adenocarcinoma in the periphery. Transformation of the benign endometrial tissues into carcinoma and squamous metaplasia were observed. A diagnosis of endometrial carcinoma in the rectum was made.

Adenocarcinoma

Investigation of the existence and biological role of L-arginine/nitric oxide pathway in human platelets by spin-trapping/EPR studies.

The aim of the present study was to apply spin trapping/EPR spectroscopy to investigate the existence and biological role of the L-arginine/nitric oxide pathway in human platelet aggregation. Three different spin traps were used: two nitroso, 3,5-dibromo-4-nitrosobenzenesulfonate (DBNBS) and 2-methyl-2-nitrosopropane (MNP), and a nitrone, 5,5-dimethyl-1-pyrroline N-oxide (DMPO). The effect of spin-trap concentration on the collagen-induced human platelet aggregation was compared to the anti-aggregatory effect caused by L-arginine. The results show that the nitroso spin traps (DBNBS and MNP) are more effective than L-arginine in preventing platelet aggregation. DMPO has virtually no effect on the collagen-induced aggregation except at a high concentration (300 mM). Furthermore, activation of platelets with a low concentration of collagen (17 micrograms/ml) and in the presence of DBNBS or MNP yields several EPR-detectable spin adducts. Some of the observed spin adducts do not correspond to those originating from the interaction of a free radical, nitric oxide (NO.) gas, with the spin traps [Arroyo, C.M. & Kohno, M. (1991) Free Radical Res. Commun. 14, 145-155]. Only one adduct of DBNBS, with a relative intensity of 0.1, observed in the washed-platelet experiment and in the presence of superoxide dismutase, is similar to the EPR spectrum obtained following a reaction of pure NO. gas with DBNBS. This suggests that the EPR spectrum of the DBNBS adduct consisting of a triplet may originate from the production of NO. by these cells. Additional DBNBS and MNP spin adducts were generated during platelet activation in the presence of Ca2+ and of a cytosol-depleted L-arginine preparation from washed platelets to which L-arginine was subsequently added. The formation of these DBNBS and MNP spin adducts were inhibited by N omega-methyl-L-arginine (MeArg, 100 microM), suggesting that these originated from a product of NO synthase. Furthermore, the formation of DBNBS and MNP spin adducts in platelet suspensions was enhanced by the presence of superoxide dismutase; however, their formation was prevented by the endothelial-derived relaxing factor (EDRF) inhibitors methylene blue and hemoglobin. The results from the MeArg and EDRF inhibitor experiments support the existence of the L-arginine/NO pathway in platelets. In addition, the prevention of spin-adduct formation by EDRF inhibitors, suggests that the mechanisms of EDRF formation and the L-arginine/NO pathway in endothelial cells and platelets are similar.(ABSTRACT TRUNCATED AT 400 WORDS)

Arginine

[A case of cat scratch disease complicated by reversible encephalopathy].

We described a eight-year-old girl with encephalopathy due to cat scratch disease. Cat scratch disease is a common cause of benign, self-limited, regional adenopathy seen among young people. Encephalopathy is uncommon but is a serious complication of cat scratch disease. Cat scratch disease with associated encephalopathy was described by Stevens in 1952. Since then there have been reports of only 39 cases in the English literature. As far as we know, this case is the first case in Japan. In cases of a rapidly progressive encephalopathy, the diagnosis of cat scratch disease should be considered.

Acute Disease

[Clinical significance of gastrointestinal decontamination under protected environment].

Many infections are caused by the patient's own oro-intestinal microbial flora under a protected environment. Thirty-eight patients with acute leukemia and two patients with blast crisis of chronic myelocytic leukemia were treated under a protected environment with or without prophylactic antibiotics. Antibiotics used for decontamination were vancomycin (V), polymyxin B (P) and nystatin (N). The number of patients in the VPN, PN and the no antibiotic group were 13, 13 and 14, respectively. While the intestinal microbial flora was almost completely eliminated in VPN group, the number of bacteria decreased slightly in PN group. The mean number of pharyngeal and anorectal bacterial species decreased most markedly in the VPN group, but there were no significant differences among the three groups. The number of febrile days was significantly lower in the VPN and PN group than the no antibiotics group with neutrophil counts of less than 100 microliters. The average number of episodes of infection per patient was lowest in VPN group and highest in the no antibiotic group. These data indicate that VPN administration is effective for eliminating intestinal bacterial flora and resultantly protecting endogenous infections.

Adolescent

[A case of delayed myeloneuropathy due to malathion intoxication].

We report a patient with serious organophosphorus-induced delayed neurotoxicity due to malathion. The patient was a 49-year-old male with a history of habitual alcohol drinking, who ingested approximately 100 ml of 50% malathion [S-1,2-bis(ethoxycarbonyl)-ethyl-0,0-dimethyl phosphorodithioate solution], with a large amount of alcohol in a suicide attempt. Following recovery from an acute cholinergic phase 36 hours after ingestion, respiratory muscle weakness, consciousness disturbance and diffuse weakness of the limb muscles occurred, necessitating mechanical ventilation. On the 7th hospital day, glove and stocking type sensory disturbance was observed and weakness of the limbs had progressed to distal dominant flaccid quadriparalysis with moderate muscle atrophy. Two months after onset, neurogenic bladder and spinal automatism became obvious. After 7 months, spasticity of the lower limbs developed, while the weakness of the upper limbs improved. Sural nerve biopsy showed axonal degeneration, loss of large myelinated fibers and increases in Schwann cell clusters. These findings were similar to those seen in patient with triorthocresyl phosphate (TOCP) intoxication. The symptoms of this patient seemed to correspond to Senanayake's "intermediate syndrome". The final clinical features and sural nerve biopsy findings were in close agreement with those in patients with serious organophosphorus compounds induced delayed neurotoxicity due to TOCP intoxication. However, this patient exhibited more severe neuropathy than seen in previously reported cases of organophosphorus compounds induced delayed neurotoxicity caused by less toxic organophosphorus compounds, such as Dipterex. This suggests that alcohol might have been an etiological factor in damage of nervous tissue in this rare case. This is the first case of organophosphorus compounds induced delayed neurotoxicity due to malathion to be reported in Japan.

Biopsy

[A case of transverse myelopathy caused by acupuncture].

A 54-year-old man received insertion of an acupuncture needle into the region extending from the posterior neck to the back on two occasions for the treatment of shoulder stiffness. Two weeks after the second acupuncture, he developed fever, dysarthria and mictionary disturbance, finally reaching the condition of tetraplegia. He was immediately admitted to an emergency room in our hospital, and was diagnosed as sepsis with DIC, ARDS, heart failure, renal failure, liver failure, and myelitis. After one month, he recovered with transverse myelopathy as a residual deficit. Neurological findings showed transverse myelopathy below the level of Th2 at that time. Cervical CT revealed an irregular low density at the periphery of the cervical vertebra from the C2 to C4 level. Cervical MRI revealed an irregular swelling of his spinal cord from the C2 to C7 level. We explained the mechanism of transverse myelopathy in this case as follows. After the acupuncture, he suffered a focal infection of the region of needle insertion, and then the infection expanded to the cervical vertebra, thus causing osteomyelitis, sepsis, and finally cervical myelitis. Direct injury of the spinal cord and nerve roots as a complication of acupuncture was previously reported, but indirect injury of the spinal cord due to myelitis had not been reported except our present case. Careful attentions should be paid to the complications of acupuncture.

Acupuncture Therapy

[Study of hormone replacement therapy following total thyroidectomy in thyroid cancer--with special reference to the analysis of thyroid hormone peripheral effects, using indirect calorimetry].

Peripheral effects of thyroid hormones were examined using an indirect calorimetry in 18 patients with thyroid cancer before and after total thyroidectomy. Peripheral effects of exogenous thyroid hormones in TSH-suppression therapy after thyroidectomy were also studied. The subjects were maintained without hormone replacement for 3 weeks after total thyroidectomy. The ratio of resting energy expenditure to basal energy expenditure (REE/BEE) was determined before operation, before hormone replacement, and 1 and 5 weeks after the beginning of replacement, and the values were compared with changes in the blood thyroid hormone levels. Positive correlations were observed between the changes in endogenous thyroid hormone levels before and after total thyroidectomy and those in REE/BEE (free T3 vs. REE/BEE; r = 0.756, p less than 0.01), suggesting that evaluation of REE/BEE is clinically useful as an index of peripheral effects of thyroid hormones. Five weeks after the beginning of hormone replacement, T4 and free T4 were slightly range, and no enhancement of energy metabolism was noted. From these findings, the post-operative TSH suppression therapy carried out at our department is considered to be justifiable also from the viewpoint of energy metabolism.

Adult

[Crossed cerebellar diaschisis demonstrated by SPECT in hemiplegic children].

Crossed cerebellar diaschisis (CCD) in twenty five children with hemiplegia were studied using single photon emission computed tomography (SPECT) with N-isopropyl-p-I-123-iodoamphetamine. Seven of twenty-five patients had cerebral palsy, and the others were impaired by acquired brain injury between ten months and fourteen years of age. CCD was demonstrated in five patients (20%), who were impaired by acquired brain injury after seven years of age. CCD could never be detected in patients with cerebral palsy. Ipsilateral cerebellar diaschisis was also demonstrated in two patients with cerebral palsy and three with early acquired brain injury before three years of age. It is suggested that diaschisis presents itself as a different form in a contralateral and ipsilateral cerebellum before three years of age from a form which presents after seven years of age.

Adolescent

[A case of acute polyradiculoneuritis associated with autonomic involvement of the pupils].

Acute polyradiculoneuritis relapses rarely, and autonomic nerve involvement is less frequent than motor cranial nerve involvement. An 11-year-old boy exhibited acute relapsing polyradiculoneuritis associated with two types of autonomic dysfunction of pupils 6 months after the onset of the disease. Parasympathetic dysfunction of pupils with ocular palsies preceded neuropathy of limbs at the onset. Thereafter, sympathetic dysfunction of pupils without ocular palsies was revealed by pupillography at the 2nd attack of limb palsies.

Autonomic Nervous System Diseases

[Low-dose danazol therapy in idiopathic thrombocytopenic purpura].

Danazol was administered orally at a dosage of 50 mg/day to 17 patients (11 females and 6 males) with idiopathic thrombocytopenic purpura refractory to steroids and/or splenectomy. The patients had not been treated with conventional dosages of danazol. The drug was suspended in four patients because of adverse effects of danazol. In 13 patients (8 females and 5 males, mean age 44 y. o.) who received the danazol therapy for more than 6 months, there were no patients with an excellent response, and one patient had a good response to the therapy. The rest of the patients did not respond to danazol.

Administration, Oral