Biomedical subjects

H Horie

Publications and source records attributed to H Horie.

At least 109 records · Page 6Linked to original sources

PubMed1994

Diabetes-induced reduction of neuronal survival in hypotonic environments in culture.

Dorsal root ganglion (DRG) neurons from streptozotocin (STZ)-induced diabetic and normal C57BL mice were exposed to three different hypotonic environments (1/2, 1/4, and 1/8 osmolar solutions). After rapid applications of these hypotonic solutions to the neurons, the cell volume autoregulatory mechanism operated in 1/2 osmolar solution but was disrupted in superhypotonic solutions below 1/4 osmolar in both kinds of mice. None of the neurons could survive 12 h after treatment with superhypotonic solutions. On the other hand, a gradual reduction of osmolarity of the culture medium enabled neurons in the normal mice to survive in 1/2 and 1/4 osmolar solutions as well as in an isotonic solution. However, this reduction of osmolarity increased neuronal cell death in the diabetic mice. These results suggest that the ability of DRG neurons to survive in hypotonic environments in culture may be lost in diabetes.

Animals↗

PubMed1994

Regional differences in neurite regeneration of postnatal mouse retinal explants.

Retinal explants from mice at postnatal days 2-15 were three-dimensionally cultured in collagen gel. The regeneration of neurites from the explants was investigated at each stage after birth. The explants from the central region in the retina could not regenerate neurites after postnatal day 9, but those from peripheral regions expressed such ability until postnatal day 12. This regional difference in the disappearance stages of retinal regenerative capability coincides with that of retinal maturation.

Aging↗

PubMed1994

Transgenic mice carrying the human poliovirus receptor: new animal models for study of poliovirus neurovirulence.

Recombinant viruses between the virulent Mahoney and attenuated Sabin 1 strains of poliovirus type 1 were subjected to neurovirulence tests using a transgenic (Tg) mouse line, ICR-PVRTg1, that carried the human poliovirus receptor gene. The Tg mice were inoculated intracerebrally with these recombinant viruses and observed for clinical signs, histopathological lesions, and viral antigens as parameters of neurovirulence of the viruses. These parameters observed in the Tg mice were different for different inoculated viruses. Dose-dependent incidences of paralysis and of death were observed in the Tg mice inoculated with any viruses used. This indicates that values of 50% lethal dose are useful to score a wide range of neurovirulence of poliovirus. The neurovirulence of individual viruses estimated by the Tg mouse model had a strong correlation with those estimated by monkey model. Consequently, the mouse tests identified the neurovirulence determinants on the genome of poliovirus that had been identified by monkey tests. In addition, the mouse tests revealed new neurovirulence determinants, that is, different nucleotides between the two strains at positions 189 and 21 and/or 935 in the 5'-proximal 1,122 nucleotides. The Tg mice used in this study may be suitable for replacing monkeys for investigating poliovirus neurovirulence.

Animals↗

PubMed1993

Macrophage-enhanced neurite regeneration of adult dorsal root ganglia neurones in culture.

To study the effects of macrophages on nerve regeneration, purified low population dorsal root ganglia (DRG) neurones from adult mice were cultured in protein-free medium (PFM) or in conditioned media (CM) from peritoneal macrophages cultured in PFM. In PFM, only 20% of the neurones survived at 5 days in culture, but the macrophage CM more than doubled the proportion of neurone survival and neurite extension of controls. These factors did not act on superior cervical ganglia (SCG) neurones, and were considered as being proteins because of their trypsin-sensitive property. Additionally, they may be different from the previously known neurotrophic factors derived from macrophages, because the target cells and effective concentration of these factors were different from those of known ones. The factors investigated in this study may play an important role in nerve regeneration.

Animals↗

PubMed1993

Isolation and age-related characterization of mouse Schwann cells from dorsal root ganglion explants in type I collagen gels.

A technique for isolation of adult Schwann cells (ScC) from dorsal root ganglia (DRG) is described. Decapsulated DRG explants embedded into type I collagen gels were cultured for 3 days in serum-free medium during which ScC migrated from the explant. These explants were then grown in serum-supplemented medium to allow ScC proliferation. On day 10 the number of ScC isolated from DRG explants per mouse was about 2.5 x 10(5), and the purity was greater than 95%. This culture system provided sufficient numbers of highly purified adult ScC in a shorter culture period (2-3 times) than other methods. We used ScC from this method to determine the age-related changes in attachment, growth, and survival of ScC cultured in serum-free medium. The attachment capacity of adult ScC on type I collagen or polylysine was similar to that of newborn ScC. However, the collagen promoted growth and survival of adult ScC but not that of neonatal ScC, indicating age-related differences of ScC properties in vitro.

Age Factors↗

PubMed1993

Preoperative combined treatment with radiation, intraluminal hyperthermia, and 5-fluorouracil suppositories for patients with rectal cancer.

A clinical trial of a novel modality consisting of preoperative irradiation and intraluminal hyperthermia therapy, with or without 5-fluorouracil (5-FU) suppositories, was conducted on 30 patients with rectal cancer. To create hyperthermia in rectal cancer, an intraluminal electrode connected to a radiofrequency system was devised. Patients were treated preoperatively with a total irradiation dose of 30 Gy, being 3 Gy every 2 days, and 5 applications of hyperthermia given twice a week, with or without 5-FU suppositories, given as 100 mg a day to a total of 2,000 mg. Twenty patients received irradiation, intraluminal hyperthermia, and 5-FU suppositories, being the three-combination treatment, and the remaining 10 received irradiation and intraluminal hyperthermia, being the two-combination treatment. Shrinkage of the rectal cancer was observed macroscopically in 26 patients, resulting in a flattened cancerous crater or shallow ulcer. Microscopic examination revealed a marked decrease in the number of cancer cells. In fact, three resected specimens showed no evidence of cancer cells microscopically. These striking reductions in cancer size enabled us to successfully perform super-low anterior resections in four patients, with anastomoses being made just above the dentate line with a sufficiently safe margin. No serious complications were encountered in this series.

Aged↗

PubMed1993

Paratesticular neuroblastoma with N-myc activation.

The authors describe a case of disseminated neuroblastoma discovered as a paratesticular tumor in a 7-month-old boy. The ectopic adrenal tissues adjacent to the paratesticular tumor and multiple lesions in the adrenal gland and skin suggested the possibility of multifocal primary tumors. Although infantile neuroblastoma diagnosed at less than 1 year of age generally responds well to treatment irrespective of distant metastases, metastases developed, and the boy died of disease within 7 months. All multiple lesions had amplification and overexpression of the N-myc protooncogene, which might explain the aggressive phenotype of this rare case.

Blotting, Northern↗

PubMed1993

Zinc deficiency exaggerates diabetic osteoporosis.

Streptozotocin diabetic rats showed an increase of bone fragility (11.9 +/- 2.1 kg/cm2 vs. 16.8 +/- 2.0, P < 0.005) which was normalized by insulin treatment (18.3 +/- 4.2), indicating that osteoporosis was induced in diabetic rats. The rats were fed a zinc-deficient diet (0.16 mg/100 g) or a control diet (5.2 mg/100 g). This mild zinc-deficient diet did not lower the serum zinc level. The cortical bone of diabetic rats was shown to be markedly thinner by microscopic examination of ground cross-sections of the tibia. Zinc deficiency induced a reduction in the calcium content of diabetic bone when compared with the rats on a control diet. Urinary excretion of calcium and phosphorus was significantly increased in diabetic rats, and increased further when the rats were fed a zinc-deficient diet. Moreover. the bone calcium and phosphorus concentrations were significantly lower in these animals. These changes in the zinc-deficiency rats were not reversed by insulin treatment. Our findings suggest that osteoporosis in the diabetic rats was due to thinning of the bone cortex secondary to mineral loss and can be reversed by insulin treatment, and that these skeletal changes are greatly enhanced by mild zinc deficiency. In addition the effects of zinc deficiency cannot be completely reversed by insulin treatment.

Alkaline Phosphatase↗

PubMed1993

Age-related changes of DRG neuronal attachment to extracellular matrix proteins in vitro.

Attachment of dorsal root ganglion (DRG) neurones from 3-month-old (young adult) and 24-month-old (aged) mice to the following substrates was evaluated after 6 h in culture: (1) poly-L-lysine (PL), (2) PL + type I collagen (CL-I), (3) PL + type IV collagen (CL-IV), (4) PL + laminin (LM) and (5) PL + fibronectin (FN). In the young adult mice, each substrate coated onto PL, significantly increased the ratio of attachment, compared with PL alone. In the aged mice, CL-I and LM, but not CL-N or FN improved the attachment. There was no difference in cell survival or neurite extension after 48 h in culture between the two groups of mice. These results suggest that ageing causes selective changes of the neuronal cell-surface receptors respective to extracellular matrix proteins such as CL-IV and FN.

Aging↗

PubMed1993

Analysis of the Gs alpha gene in growth hormone-secreting pituitary adenomas by the polymerase chain reaction-direct sequencing method using paraffin-embedded tissues.

We investigated the prevalence of Gs alpha gene mutations in growth hormone (GH) secreting pituitary adenomas from Japanese patients with acromegaly. Forty-five GH-secreting adenomas were examined for the presence of point mutations in codons 201 or 227 of the Gs alpha gene using the polymerase chain reaction-direct sequencing method and deoxyribonucleic acid extracted from paraffin-embedded tumor specimens. Mutation of codon 227 of the Gs alpha gene was not observed in any of the tumors, but a mis-sense mutation of codon 201 was identified in two tumors (4.4%). One lesion was a densely granulated GH cell adenoma in a patient with adenomatous goiter and breast cancer. The other was a mixed GH cell-prolactin cell adenoma in a patient with multiple endocrine neoplasia type 1 associated with parathyroid hyperplasia and a pancreatic islet cell tumor. The Gs alpha gene detected in parathyroid tissue and pancreatic tumor tissue was of the wild type in this second patient, and the mutation was specific to the pituitary tumor. These results suggest that point mutations of codons 201 or 227 of the Gs alpha gene may not be important mediators of oncogenesis for GH-secreting pituitary adenomas in Japan.

Adenoma↗

PubMed1993

Response of aged neurons to super-hypotonic environment.

Cultured sensory neurons from aged mice (24 months old) lost capability of cell volume auto-regulatory mechanism after the rapid treatment with a hypotonic solution of 1/4 the normal osmolarity or lower. However, they could survive and extend neurites in super-hypotonic media such as 1/4 osmolar and even 1/8 osmolar culture media when the osmolarity was reduced gradually to such a low level.

Aging↗

PubMed1993

Poliovirus-sensitive transgenic mice as a new animal model.

Transgenic mice susceptible to poliovirus infection were produced by introducing a human gene encoding cellular receptors for poliovirus into the mouse genome. Expression of receptor mRNAs in tissues of the transgenic mice was analysed using Northern blot hybridization. The results indicate that the human gene is expressed in many tissues of the transgenic mice just as in human tissues, and that the amount of the receptor mRNAs varies from tissue to tissue. The transgenic mice inoculated with poliovirus by any of the routes tested in this study show clinical symptoms similar to those in humans and monkeys, although the sensitivity of the mice depended on the inoculation route. In any route, the virulent Mahoney strain of type 1 poliovirus is much more virulent than the attenuated Sabin 1 strain in the transgenic mice. These observations suggest that the transgenic mice become an excellent new animal model for studying molecular mechanisms of pathogenesis of poliovirus and for assessing oral poliovirus vaccines.

Administration, Oral↗

PubMed1993

[MRI and autopsy findings in the brain of a child born with extreme prematurity].

We present the brain autopsy and MRI findings in a four-year-old boy who was born at 23 weeks of gestational age and 700 gram of birthweight and experienced an episode of cardiac arrest at 10 months of age. Neuropathological study showed the findings compatible with cardiac arrest syndrome, the gliosis or neuronal loss of extensive cerebral lesions including the cerebral white matter and cortex, basal ganglia, cerebellum and hippocampus, and large ulegyric formation in the bilateral parietal and occipital lobes, as well as the periventricular leukomalacia, which characterize hypoxic-ischemic insult in the brain of preterm infant. MRI performed eight months before his death demonstrated prominent atrophy and periventricular and parenchymal hyperintensity of the bilateral occipital lobes consistent with the above pathological findings.

Atrophy↗

PubMed1992

Prediction of viability of ischemically damaged canine pancreatic grafts by tissue flow rate with machine perfusion.

We studied the viability of canine pancreatic grafts using a short-time perfusion technique with an organ perfusion machine, "ORPH3000C". The following parameters were examined during perfusion of warm ischemically damaged grafts: Amylase, lipase, and insulin levels in the perfusate after 1-hr perfusion showed no significant correlation with warm ischemic time (WIT), and these indices could not be used to assess graft viability. Tissue flow rate (TFR) at the end of perfusion was significantly decreased with prolonged WIT. TFR correlated with the percent decrease in tissue SOD activity, thus TFR was a reliable predictor of reperfusion injury. Histological studies showed no findings attributable to warm ischemic injury before 1-hr perfusion. After 1-hr perfusion, the grafts were allotransplanted and the relation between TFR and endocrine function of the transplanted grafts was examined. TFR correlated with K value calculated from IV-GTT performed on day 5 postoperatively, suggesting that TFR is a predictable index of isolated pancreatic graft viability. Using TFR levels, this method allowed us to select only grafts with good function prior to transplantation. This technique appears to be of use for pancreatic transplantation from cadaver donors after cardiac arrest.

Animals↗

PubMed1992

Treatment for B-cell-type lymphoma in a girl associated with Bloom's syndrome.

A 12-year-old girl suffering from Bloom's syndrome developed B-cell-type lymphoma in the epipharynx. She was identified as having Bloom's syndrome at the age of 3. While the tumor was eradicated completely by induction chemotherapy, the bone marrow suppression was severe and persistent. For this reason, we modified subsequent chemotherapy to a milder form. Thus the remaining therapy could be safely completed. This is the first case clearly diagnosed as having epipharyngeal B-cell-type lymphoma in the Bloom's Syndrome Registry.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1992

Cytogenetic characteristics of a malignant rhabdoid tumor arising from the paravertebral region. A case report.

The pathological and cytogenetic features of an extrarenal malignant rhabdoid tumor (MRT) arising from the paravertebral region in an infant were investigated. The patient died 4 months after diagnosis, due to aggressive tumor progression. The tumor was composed of medium-sized round cells with cytoplasm containing eosinophilic inclusions, which ultrastructurally were composed of densely packed whorled intermediate filaments. Flow-cytometric analysis of the tumor cells revealed a diploid pattern. Amplification of the N-myc oncogene was not identified. Immunohistologically, the inclusion bodies showed a positive reaction with antiserum against vimentin. The tumor cells were not reactive with antiserum against epithelial membrane antigen, anti-keratin (polyclonal) or cytokeratin (monoclonal, CK1), but did react with 5H10, an antiserum established from human sarcomatous Wilms' tumor. This case is discussed with reference to the literature on extrarenal MRT, placing stress on the histogenesis of this tumor.

Female↗

PubMed1992

Neonatal Legionnaires' disease. Histopathological findings in an autopsied neonate.

A neonatal case of legionnaires' disease (LD) is reported. A male neonate was admitted to our hospital with high fever and dyspnea, which had started 5 days after birth, and died due to severe pneumonia at 10 days old. An autopsy revealed small areas of granular consolidation scattered diffusely in the bilateral lungs. Microscopic examination of the lungs showed mainly lobularly distributed pneumonia. Extensive exudation of macrophages and neutrophils was observed in the terminal respiratory tract and alveolar spaces. Warthin-Starry and Gimenez staining and electron microscopy detected many coccobacilli in the cytoplasm of exudated macrophages and neutrophils. Immunofluorescence staining using antiserum against Legionella pneumophila, serogroup 1, showed a positive reaction. Bacteriological examinations of aspirate from the respiratory tract and autopsied lung tissue confirmed the presence of Legionella pneumophila, serogroup 1. Extrapulmonary LD was not detected. LD usually affects aged or immunocompromised hosts, but there was no evidence of immune deficiency in this case. Pediatric cases of LD have rarely been reported, and a survey of the literature revealed few neonatal cases. The present case may alert neonatologists and other medical personnel to the possibility of neonatal LD infection.

Autopsy↗

PubMed1991

Inhibition of nociceptive neurons in the shell region of nucleus ventralis posterolateralis following conditioning stimulation of the periaqueductal grey of the cat. Evidence for an ascending inhibitory pathway.

Recordings were made from neurons in the ventroposterior lateral nucleus (VPL) of urethane chloralose-anaesthetised cats, following both noxious mechanical stimulation of the integument, and electrical stimulation of the inferior cardiac nerve. The effects of stimulating the periaqueductal grey (PAG), or the nucleus raphe dorsalis (NRD) on the responses obtained from these units were also investigated. Units responding to noxious mechanical stimulation of the integument, with inferior cardiac nerve input, were found only around the periphery of the posterior half of VPL. Responses elicited from these units by electrical stimulation of the inferior cardiac nerve were inhibited following electrical stimulation of either the ventral PAG or the NRD. Inhibition following PAG or NRD stimulation could still be demonstrated after bilateral section of the dorsolateral funiculi at the junction between C3 and C4, although the degree of inhibition decreased. Responses elicited from these units by electrical stimulation of the anterolateral funiculus were also inhibited following PAG or NRD stimulation. These data suggest that PAG or NRD stimulation-produced inhibition of these units may be partially mediated by an ascending pathway, in addition to the well-known descending spinal pathways in the dorsolateral funiculi of the spinal cord.

Analgesia↗