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Biomedical subjects

H Kurihara

Publications and source records attributed to H Kurihara.

At least 217 records · Page 12Linked to original sources
PubMed1996

Altered bile acid metabolism related to atherosclerosis in alloxan diabetic rats.

Normal and alloxan diabetic rats were kept on a 0.25% cholesterol diet for 12 months and the changes in serum cholesterol levels, and fecal excretion of sterols and bile acids were examined to elucidate the influence of changes in bile acid metabolism on manifestations of hypercholesterolemia and development of atheromatous lesions. Diabetic rats fed the cholesterol diet showed increases in bile acid synthesis and in the cholic acid group/chenodeoxycholic acid group (CA/CDCA) ratio, and developed significant hypercholesterolemia and atheromatous lesions. In contrast, normal rats showed increased bile acids synthesis but a decreased CA/CDCA ratio after feeding with the cholesterol diet, and developed neither hypercholesterolemia nor atheromatous lesions. Fecal sterol excretion and the cholesterol/sitosterol ratio decreased in diabetic rats. Positive correlations were found between the cumulative serum cholesterol level and the atheromatous lesion area, and between the fecal CA/CDCA ratio and the serum cholesterol level, in the latter of which the correlation was higher in rats on the cholesterol diet than in those on the standard diet. These findings suggest that alteration of bile acid metabolism with increases in cholic acid synthesis and CA/CDCA ratio in diabetic rats enhances cholesterol absorption to produce significant hypercholesterolemia, which in turn leads to development of atheromatous lesions.

Alloxan↗
PubMed1996

[Surgical treatment of traumatic rupture of the aortic valve].

Rupture of the aortic valve after a blunt chest trauma is rare. A 63-year-old man was injured in an automobile accident and was hospitalized elsewhere due to acute respiratory failure 4 days after the accident. On admission, he was intubated immediately. The patient did not respond to available medical treatments and was therefore transferred to our hospital. His condition was diagnosed as severe left heart failure, and an emergency operation was performed. The right coronary and non-coronary cusps were perforated and the commissure between the right coronary and non-coronary cusps was torn. The aortic valve was excised and a SJM 25 AEC prosthetic valve was inserted. The patient recovered well postoperatively.

Accidents, Traffic↗
PubMed1996

Clinical evaluation of a dental rinse containing aluminum lactate for treatment of dentinal hypersensitivity.

The effectiveness of a dental rinse containing aluminum lactate, which was used as a daily home treatment for dentinal hypersensitivity, was evaluated in a 6-week, double-blind study. Fifty-six subjects who complained of cold and/or tactile hypersensitivity were randomly divided into two groups: one given a dental rinse containing 2.18% aluminum lactate (test group) and the other a vehicle control dental rinse (control group). Subjects in both groups were instructed to rinse with the assigned dental rinse and to brush their teeth twice daily. The hypersensitivity levels of the affected teeth were assessed at baseline and at 4 and 6 weeks by application of tactile, cold air and cold water stimuli, and scored against baseline. All hypersensitivity scores in both groups were decreased significantly at weeks 4 and 6 compared to the baseline (p < 0.001). The hypersensitivity scores for tactile, cold air and cold water stimuli in the test group were significantly lower at weeks 4 and/or 6 compared to those in the control group (p < 0.05). Furthermore, on the analysis for the teeth with apparent pain (score 2 or 3) at the baseline, the reduction rates of hypersensitivity scores for cold air and cold water stimuli in the test group were significantly greater than those in the control group (p < 0.05). These findings suggest that daily home use of a dental rinse containing aluminum lactate is effective for treatment of dentinal hypersensitivity.

Adult↗
PubMed1995

Impaired synapse elimination during cerebellar development in PKC gamma mutant mice.

PKC gamma is highly expressed in Purkinje cells (PCs) but not in other types of neurons in the cerebellum. The expression of PKC gamma changes markedly during cerebellar development, being very low at birth and reaching a peak around the third postnatal week. This temporal pattern of PKC gamma expression coincides with the developmental transition from multiple to single climbing fiber innervation onto each PC. In adult mutant mice deficient in PKC gamma, we found that 41% of PCs are still innervated by multiple climbing fibers, while other aspects of the cerebellum including the morphology and excitatory synaptic transmission of PCs appear normal. Thus, elimination of multiple climbing fiber innervation appears to be specifically impaired in the mutant cerebellum. We suggest that the developmental role of PKC gamma may be to act as a downstream element in the signal cascade necessary for the elimination of surplus climbing fiber synapses.

Age Factors↗
PubMed1995

Expression of the hepatocyte growth factor gene during chick limb development.

It has been shown that mirror-image duplications of the zeugopodia and digits are formed when MRC-5 fibroblasts producing hepatocyte growth factor (HGF) are applied to the anterior region of the chick limb bud (Yonei et al. [1993] Dev. Biol. 160:246-253). To evaluate the role of HGF in limb development, we observed the expression pattern of the HGF gene using in situ hybridization. The HGF gene was expressed in the mesoderm of the limb bud and in the central core region of mandibular arch and maxillary processes at stages 17 to 24. When both wing and leg buds begin to extend distally, the HGF gene is expressed in the mesenchymal cells, but not in the ectodermal cells and somites. Concomitant with establishment of the apical ectodermal ridge, distal mesenchymal cells of the limb bud express the HGF gene intensely with a gradient higher in the distal region. The HGF expression is later confined to the ventral and subapical mesenchyme of the limb bud, although no signal is detectable in the apical and non-ridge ectoderm. However, signal for the c-met proto-oncogene encoding the HGF receptor is not detectable in the limb bud at stages 17 to 24. These results suggest that HGF produced in the limb mesoderm may be involved in initial induction and maintenance of the apical ectoderm during limb development.

Animals↗
PubMed1995

Calcified astrocytoma of the amygdalo-hippocampal region in children.

Three pediatric cases of temporal lobe seizure due to calcified glioma of amygdalo-hippocampal region are described. Computed tomography and magnetic resonance imaging showed dense calcification with no postcontrast enhancement in the amygdalo-hippocampal region. Positron emission tomography showed low oxygen metabolism, low glucose metabolism, hypermetabolism of amino acids, and low regional cerebral blood flow in the tumors. Single photon emission computed tomography showed a high accumulation of 201Tl chloride and 123I-isopropyl iodoamphetamine in one tumor, but otherwise low radioisotope uptake. These studies indicated low-grade malignancies. The patients were treated by partial tumor removal and radiotherapy. Histological examination of the tumor specimens showed astrocytoma with interstitial calcification. One patient died due to tumor recurrence, while the others are doing well with minimal seizure. We recommended temporal lobectomy in similar cases to achieve complete remission.

Adolescent↗
PubMed1995

Synthesis of 15 alpha-hydroxyestrogen 15-N-acetylglucosaminides.

The synthesis of 15-N-acetylglucosaminides of 15 alpha-hydroxyesterone, 15 alpha-hydroxyestradiol, and 15 alpha-hydroxyestriol (estetrol) is described. The latter two were prepared by condensation of 2-acetamido-1 alpha-chloro-1,2-dideoxy-3,4,6-trio-O-acetyl-D-glucopyranose with appropriately protected 15 alpha-hydroxyestrogens by the Koenigs-Knorr reaction employing cadmium carbonate as a catalyst. Subsequent removal of protecting groups with methanolic potassium hydroxide provided the desired conjugates. 15 alpha-Hydroxyestrone 15-N-acetylglucosaminide was synthesized from the corresponding 15 alpha-hydroxyestradiol derivative by Jones oxidation followed by brief alkaline hydrolysis. These conjugates underwent enzymatic hydrolysis with beta-N-acetylglucosaminidase from Jack beans to produce 15 alpha-hydroxyestrogens.

Acetylglucosaminidase↗
PubMed1995

A microbiological and immunological study of endodontic-periodontic lesions.

The microflora and humoral immune response in tissue from the periodontal pockets and root canals of five teeth with endodontic-periodontic lesions were examined. We found more microbes in the periodontal pockets than in the root canals. The flora in the periodontal pockets was dominated by rods and motile organisms, whereas that in the root canals was largely rods and cocci. We detected no spirochetes in the root canals. The cultivable microflora in the periodontal pockets comprised a high number of different species of bacteria, whereas those in the root canals included only a small number of species. There was no correlation between microbial isolates and antibody titer in the apical tissues or periodontal pockets. We conclude from these studies that the microflora of infected root canals is simple and limited, and that the local humoral immune response does not seem to affect the pathogenesis of disease directly.

Antibodies, Bacterial↗
PubMed1995

Clinical, microbiological and host defense parameters associated with a case of localized prepubertal periodontitis.

A 4-year-old Japanese boy was referred to Osaka University Dental Hospital because of severe mobility and pain of the right lower primary canine. The canine had severe bone loss and a pocket depth exceeding 5-6 mm. The left lower canine showed slight mobility and moderate alveolar bone loss. The other primary teeth showed no pathogenic findings. The subgingival microflora from the right lower canine was dominated by gram-negative rods, especially capnocytophaga and fusobacterium, while actinomyces sp. were the most common gram-positive bacteria. While neutrophil functions of the patient were within the normal ranges of healthy subjects, some lymphocyte functions such as IL-2 production and IgG and IgM syntheses were lower in the patient. 7 months after the extraction of the right lower primary canine, the patient complained of pain around the right lower primary lateral incisor. In 3-4 weeks, the alveolar bone was lost rapidly and mobility of the lower anterior teeth increased significantly. The primary lateral incisor was extracted and the other primary teeth were treated by sealing and systemic and local administration of antibiotics. After treatment, the lower anterior teeth became less mobile and the gram-positive cocci predominated.

Actinomyces↗
PubMed1995

Response of human gingival fibroblasts to prostaglandins.

The effects of various prostaglandins (PGs) on the functions of human gingival fibroblasts (Gin-1 cells; ATCC CRL 1292) were examined by phase-contrast microscopy, cell-counting and radioautographic experiments. Tested PGs were PGA1, PGA2, PGB1, PGB2, PGD2, PGE1, PGE2, PGF1 alpha, PGF2 alpha, PGI2, 6-keto-PGF1 alpha, 9 alpha-11 alpha-methanoepoxy-PGF2 alpha, and thromboxane (TX) B2. PGA1 and PGD2 at 30 microM caused morphological deformation of Gin-1 cells. All the PGs tested at 30 microM suppressed the proliferation of Gin-1 cells in the logarithmic growth phase. Furthermore, all the PGs tested at 10 microM suppressed DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in confluent Gin-1 cells, while exerting no effect on GAG synthesis. The concentrations of PGs used are beyond those found in healthy gingiva. However, in periodontitis the local concentrations of some PGs within the gingiva are expected to be extremely elevated beyond the physiological level. These results suggest that PGs may play an important role as a negative regulator in metabolism and some pathologic gingival conditions by suppressing the functions of gingival fibroblasts.

Cell Division↗
PubMed1995

Increased Tyr phosphorylation of ZO-1 during modification of tight junctions between glomerular foot processes.

The slit diaphragms between the glomerular epithelial foot processes represent a variant of the tight junction that are rapidly replaced by typical tight junctions after perfusion with protamine sulfate (PS). To investigate the mechanism of signaling involved, tyrosine phosphorylation of glomerular proteins was analyzed in newborn, PS-treated, and control rats using antiphosphotyrosine immunoglobulin G. In glomeruli of normal adults, phosphotyrosine (Ptyr) staining was confined largely to mesangial cells by immunofluorescence, whereas in newborn and PS-treated rats, the Ptyr signal was dramatically increased in the glomerular epithelium. By immunogold labeling, it was found that newly phosphorylated proteins were concentrated along the newly formed tight junctions (cell-cell junctions) and the basal membrane of the foot processes (cell-matrix junctions). By immunoblotting, several prominent bands were detected with anti-Ptyr in glomerular lysates of controls; in PS-treated rats, additional bands were detected at 225, 180, and 100 kDa. The 225-kDa protein was identified as ZO-1 by immunoprecipitation with anti-ZO-1 followed by immunoblotting with anti-Ptyr. These findings indicate that ZO-1 is one of the targets for tyrosine phosphorylation after PS treatment. They indicate that phosphorylation of tight junction and other proteins occurs during the formation of tight junctions in glomeruli under circumstances where there are rapid changes in epithelial cell shape.

Animals↗
PubMed1995

Classification of arteriovenous malformations for radiosurgery. Neuroimaging, histopathology and radiobiologic effects.

Arteriovenous malformations (AVMs) were classified based on morphologic and hemodynamic factors. They were categorized as Moya type, shunt type or mixed type on the basis of hemodynamic factors, and as homogeneous or heterogeneous types on the basis of morphology. Histopathologic and radiobiologic characteristics were evaluated with respect to these AVM types. Classification depending on the type as well as the size of an AVM is important for modern treatment modalities, especially radiosurgery.

Cerebral Angiography↗
PubMed1995

Targeting gene expression to the vascular wall in transgenic mice using the murine preproendothelin-1 promoter.

To develop a system for overexpressing genes in the vascular wall, we created transgenic mice using the reporter gene luciferase and the murine preproendothelin-1 promoter. In vitro analysis suggested that the murine 5'-flanking region contained endothelial-specific elements in a 5.9-kb fragment. Five transgenic mice colonies established from independent founders all exhibited the highest level of luciferase activity in the aorta with up to 8,540 light units per microgram of protein. Immunohistochemistry with anti-luciferase antisera revealed high levels of expression in the endothelial cells of both large and small arteries and lower levels of expression in veins and capillaries. Significant expression was also seen in arterial smooth muscle cells and in select epithelial surfaces which is consistent with the known distribution of endothelin-1 in mammals. The further demonstrate the targeting capability of this system, we overexpressed the lipid-peroxidating enzyme, human 15-lipoxygenase, in the vessel wall of transgenic mice. As with luciferase, expression of active enzyme and immunohistochemical localization in vascular cells were documented in transgenic animals. Hence, this new system can be used to direct expression of molecules to the vascular wall for the purpose of examining the biological significance of either overexpression or inhibition of select proteins.

Animals↗
PubMed1995

Aortic arch malformations and ventricular septal defect in mice deficient in endothelin-1.

Endothelin-1 (ET-1) is a 21-amino acid peptide with various biological activities including vasoconstriction and cell proliferation. To clarify the physiological and pathophysiological role of ET-1, we disrupted the mouse Edn1 locus encoding ET-1 by gene targeting and demonstrated that ET-1 is essential to the normal development of pharyngeal arch-derived tissues and organs. In this study, we focused on the phenotypic manifestations of Edn1-/- homozygous mice in the cardiovascular system. Edn1-/- homozygotes display cardiovascular malformations including interrupted aortic arch (2.3%), tubular hypoplasia of the aortic arch (4.6%), aberrant right subclavian artery (12.9%), and ventricular septal defect with abnormalities of the outflow tract (48.4%). The frequency and extent of these abnormalities are increased by treatment with neutralizing monoclonal antibodies or a selective ETA receptor antagonist BQ123. At an earlier embryonic stage, formation of pharyngeal arch arteries and endocardial cushion is disturbed in Edn1-/- homozygotes. In situ hybridization confirmed ET-1 expression in the endothelium of the arch arteries and cardiac outflow tract and the endocardial cushion as well as in the epithelium of the pharyngeal arches. Thus, ET-1 is involved in the normal development of the heart and great vessels, and circulating ET-1 and/or other ET isoforms may cause a functional redundancy, at least partly, through the ETA receptor.

Animals↗
PubMed1995

Studies on the phenotypic and functional characterization of peripheral blood lymphocytes from patients with early-onset periodontitis.

Juvenile and rapidly progressive periodontitis are grouped under the heading of patients with early-onset periodontitis (EOP). Many studies have investigated host risk factors in the etiology of EOP patients but these remain inconclusive. This study was undertaken to assess the possibility that an abnormality in the systemic lymphocyte subpopulation or function is involved in the etiology of EOP patients. Fourteen (14) patients with juvenile periodontitis (JP), 18 with rapidly progressive periodontitis (RPP), 22 with adult periodontitis (AP), and 33 with a healthy periodontium (HP) participated in this study. Lymphocyte subsets were determined by using panels of monoclonal antibodies (mAbs) and fluorescent flow cytometry. T cell blastogenesis was evaluated by [3H]-thymidine uptake. Pokeweed mitogen induced immunoglobulin G (IgG) and IgM synthesis were detected by sandwich enzyme-linked immunosorbent assay. There were wide distributions of values in all examinations among subjects. No significant difference could be found between the periodontitis patients and HP groups with the exception of a high CD4/CD8 ratio in all patient groups (P < 0.0001) and the depressed percentages of CD3 positive cells noted in the AP patient group (P < 0.0001). These results suggest that the majority of EOP patients do not show significantly different lymphocyte profiles from AP patients and HP subjects, and that lymphocyte cell dysfunctions are not always seen, even in EOP patients.

Adolescent↗
PubMed1995

Clinical and laboratory studies on a patient with early onset periodontitis and her family members. A case report.

Extensive clinical, microbiological, hematological, and immunological studies were performed on a patient with early onset periodontitis (EOP) and two other members of the family. The proband, a 27-year-old female, had early onset periodontitis and a high level of serum rheumatoid factors (RF) with no diagnosable medical disease. Her mother had lost all her teeth at the age of 50 because of advanced periodontitis, while her elder sister was unaffected by periodontitis. Neither the proband's periodontally-affected mother nor her unaffected sister exhibited a detectable level of RF. In this study, we examined: 1) serum immunoglobulin G (IgG) antibody titers against putative periodontal pathogenic bacteria; 2) peripheral neutrophil functions; 3) phenotypic analyses of peripheral lymphocyte subpopulations; and 4) peripheral lymphocyte functions (T cell proliferative activity, ability of cytokine [interleukin (IL)-2, tumor necrosis factor-alpha, interferon-gamma, IL-6 and IL-8] and IgG and IgM productivity). High antibody titers to Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Campylobacter rectus were detected in the sera of the proband, as were high serum antibody titers to P. gingivalis in the mother and to C. rectus in the unaffected sister compared to the non-periodontitis affected subjects. The proband also showed enhanced neutrophil chemotaxis; a high percentage of pan-B cells; and high productivity of IL-6, IgG, and IgM compared to individuals who were not periodontally affected. The mother showed slightly low helper/induced T cells (Th/i) suppressor/cytotoxic T cells (Ts/c) ratios due to the elevated count of Ts/c, and high IFN-gamma productivity compared to control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

alpha-Difluoromethylornithine increases the anti-tumor effect of cis-diamminedichloroplatinum in G-XII rat glioma.

The in vivo effects of the single or combined administration of alpha-difluoromethylornithine (DFMO), an inhibitor of polyamine synthesis, and cis-diamminedichloroplatinum (cisplatin) on the growth of G-XII glioma cells inoculated subcutaneously in rats were tested. Treatment with DFMO or cisplatin significantly decreased the bromodeoxyuridine (BrdU) labeling index of tumor tissues. Combined treatment with DFMO and cisplatin achieved a further significant decrease in the BrdU labeling index. All treatments significantly reduced the tissue levels of N1-acetylspermidine and putrescine, and the ornithine decarboxylase (ODC) activity, but little affected the tissue levels of spermidine and spermine, and the activity of spermidine/spermine N1-acetyltransferase. The reduction of ODC activity by cisplatin treatment may be associated with the anti-tumor effect.

Acetyltransferases↗