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Biomedical subjects

H Kawaguchi

Publications and source records attributed to H Kawaguchi.

At least 289 records · Page 16Linked to original sources

Treatment with a combination of low-density lipoprotein aphaeresis and pravastatin of a patient with drug-resistant nephrotic syndrome due to focal segmental glomerulosclerosis.

Results of recent animal studies have lent support to the hypothesis that hyperlipidaemia may contribute to renal injury. This report documents the case of a 15-year-old boy with drug-resistant nephrotic syndrome due to focal segmental glomerulosclerosis (FGS) who showed an improvement in renal function and proteinuria as a result of treatment with low-density lipoprotein aphaeresis (LDL-A) combined with pravastatin. Although further work is required to determine the efficacy of lipid-lowering therapy in progressive glomerular disease in humans, the combination of LDL-A and pravastatin is likely be included in the choice of treatment modalities available for patients with drug-resistant nephrotic syndrome due to FGS.

Adolescent↗

Dating the primigenial C4-CYP21 duplication in primates.

C4 and CYP21 are two adjacent, but functionally unrelated genes residing in the middle of the mammalian major histocompatibility complex (Mhc). The C4 gene codes for the fourth component of the complement cascade, whereas the CYP21 gene specifies an enzyme (cytochrome P450c21) of the glucocorticoid and mineralocorticoid pathways. The genes occur frequently in multiple copies on a single chromosome arranged in the order C4 ... CYP21 ... C4 ... CYP21. The unit of duplication (a module) is the C4-CYP21 gene pair. We sequenced the flanking regions of the C4-CYP21 modules and the intermodular regions of the chimpanzee, gorilla, and orangutan, as well as the intermodular region of an Old World monkey, the pigtail macaque. By aligning the sequences, we could identify the duplication breakpoints in these species. The breakpoint turned out to be at exactly the same position as that found previously in humans. The sequences flanking paralogous genes in the same species were found to be more similar to one another than sequences flanking orthologous genes in different species. We interpret these results as indicating that the original (primigenial) duplication occurred before the separation of apes from Old World monkeys more than 23 million years ago. The nature of the sequence at the breakpoint suggests that the duplication occurred by nonhomologous recombination. Since then, the C4-CYP21 haplotypes have been expanding and contracting by homologous crossing over which has homogenized the sequences in each species.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

3-Isopropylmalate dehydrogenase from chemolithoautotroph Thiobacillus ferrooxidans: DNA sequence, enzyme purification, and characterization.

3-Isopropylmalate dehydrogenase encoded by the Thiobacillus ferrooxidans leuB gene was purified to homogeneity from Escherichia coli cells harboring a recombinant plasmid containing the leuB gene. The native enzyme molecule is a dimer of molecular weight 38,000. The Km value for 3-isopropylmalate was estimated to be 26 microM and that for NAD+ 0.8 mM. The presence of K+ or NH4+ is essential for the enzyme reaction. The enzyme is activated about 4-fold by the addition of 1.0 mM Mg2+ or Co2+. The optimum pH and temperature for the activity are 9.0 and 60 degrees C, respectively. The properties of the enzyme are similar to those of the Salmonella typhimurium and Thermus thermophilus enzymes, except for substrate specificity. T. ferrooxidans 3-isopropylmalate dehydrogenase is able to utilize D- and L-malate as substrates in addition to 3-isopropylmalate. Sequencing of subcloned DNA revealed that the leuB gene consists of a 1,074 bp open reading frame and encodes 358 amino acid residues corresponding to the subunit (38,462 Da). The amino acid sequence of 3-isopropylmalate dehydrogenase from T. ferrooxidans and those of some heterotrophic microorganisms have high homology.

3-Isopropylmalate Dehydrogenase↗

Moyamoya disease associated with bilateral renal artery stenosis.

Recent research has suggested that an association exists between moyamoya disease and fibromuscular dysplasia which involves systemic vessels, including renal arteries. We report a 3 year old girl with moyamoya disease associated with bilateral renal artery stenosis. This case may support the common etiology of these two clinical conditions. To our knowledge this is the youngest case of moyamoya disease associated with bilateral renal artery stenosis.

Aortography↗

Characteristic glomerular lesions in the ExHC rat: a unique model for lipid-induced glomerular injury.

ExHC rats were bred from the Sprague-Dawley strain and are highly susceptible to dietary hypercholesterolemic stimuli. Although chemical and histological examination of the aorta from ExHC rats fed a diet containing 3% cholesterol, 0.6% sodium cholate and 15% olive oil (high-cholesterol diet, HCD) has been reported, renal injury in this model has not been investigated to date. Therefore, we examined the renal pathological changes and proteinuria in this model. ExHC rats fed an HCD developed proteinuria and characteristic glomerular lesions within 4-8 weeks after initiation of the diet. The most striking glomerular change observed in this model was the marked accumulation of numerous lipid-filled foam cells, with a surface marker that identified them as macrophages, within the mesangial regions which could have been involved in focal and segmental glomerular sclerosis. Our study demonstrates that ExHC rats fed a cholesterol-supplemented diet develop glomerular injury that may be mediated by infiltrating macrophages. These results imply that ExHC rats may be well-suited for the use in investigations of the role of macrophages in the pathogenesis of lipid-induced glomerular injury.

Animals↗

Genetic control of delayed-type hypersensitivity to chromium chloride.

Genetic control of delayed-type hypersensitivity (DTH) to chromium chloride antigen was studied in various strains of mice. Mice with I-Ab,d,f,k,r were high magnitude responders, whereas those with I-Aq,s were low magnitude responders. Studies with recombinant strains indicate that chromium chloride DTH may be influenced by the I-A region of H-2. DTH to chromium chloride is an antigen-specific response. We further revealed that response to chromium chloride does not cross-react with response to cobalt or nickel chloride. Also, transfer experiments using lymph node cells suggest that these responses are mediated by CD4+8-, Ia-T cells.

Animals↗

Phosphatidylinositol metabolism in hypertrophic rat heart.

The accumulation of inositol 1,4,5-trisphosphate (IP3) after hormonal stimulation has a physiological role, possibly by alteration of Ca2+ levels in cardiac myocyte. However, this accumulation has not been studied under pathophysiological conditions. In this report, we examine phosphatidylinositol metabolism during cellular response to norepinephrine in pressure-overloaded hypertrophic rat heart. After stimulation with norepinephrine, the accumulations of IP3 and diacylglyceride significantly increased in isolated myocytes from stroke-prone spontaneously hypertensive rat (SHRSP) heart, indicating phosphatidylinositol-specific phospholipase C activity increased in SHRSP heart cells. Protein kinase C activity was also enhanced in SHRSP, with a marked increase in particulate activity. We determined the intracellular calcium concentration and found it to be higher in SHRSP than in Wistar-Kyoto (WKY) rats at 30-40 weeks of age. Ca2+ influx was also elevated in SHRSP stimulated by norepinephrine. In SHRSP heart, cytosolic Ca2+ concentration may rise quickly in response to some stimuli, such as alpha 1-adrenergic stimulation, which is shown to be one of the pathways that increases cytosolic Ca2+ levels in hypertrophied rat heart. These data suggest that a part of the phosphatidylinositol-turnover pathway, such as the phosphatidylinositol 4,5-bisphosphate-IP3-Ca2+ pathway or the diacylglyceride-protein kinase C pathway, may play an important role in the development of hypertrophy in SHRSP heart.

Animals↗

Preparation of peptide-carrying microspheres with bioactivity on platelets.

A tetrapeptide RGDS (Arg-Gly-Asp-Ser), which is one of the active sites of cell adhesive proteins, was synthesized according to the solution method and covalently coupled onto monodisperse microspheres. The biospecific activity of the RGDS-carrying microspheres was investigated by measuring the stimulatory effect of the microspheres on platelets. Large and tightly packed platelet aggregation accompanied with drastic ATP release was induced by the RGDS-carrying microspheres. It was confirmed that the specific platelet aggregation was attributed to the activity of the immobilized RGDS by comparison with those induced by other microspheres.

Acrylamides↗

Mechanism of cytoplasmic calcium changes in platelets in contact with polystyrene and poly(acrylamide-co-methacrylic acid) surfaces.

Changes in cytoplasmic free calcium levels ([Ca2+]i) in platelets in contact with polystyrene (PSt) and poly(acrylamide-co-methacrylic acid) (PAAmMAc) particles were evaluated and results were compared with those from two representative biological calcium agonists; thrombin and calcium ionophore A23187. PSt particles stimulated a steep increase in cytoplasmic calcium levels in platelets as much as thrombin and A23187. Serratia protease-treated platelets showed a steep increase in [Ca2+]i by PSt particles, suggesting that PSt surfaces can initiate platelet activation independent of a glycoprotein Ib (GPIb)-mediated pathway. By contrast, dibucaine-treated platelets showed little increase in [Ca2+]i by PSt particles, indicating that microfilament assembly, including binding of GPIb with actin binding protein, should be required for platelet activation in contact with PSt surfaces. PAAmMAc particles induced little increase in cytoplasmic calcium levels in platelets. However, PAAmMAc particle-treated platelets demonstrated little response to thrombin in terms of an increase in [Ca2+]i and ATP release, suggesting the possibility that PAAmMAc surfaces may regulate [Ca2+]i by influencing platelet metabolism. Furthermore, sodium azide-treated platelets showed an increase in [Ca2+]i in platelets when contacting PAAmMAc particles, supporting the suggestion that PAAmMAc surfaces could regulate platelet functions. Fluorescence polarization measurements using 1,6-diphenyl-1,3,5-hexatriene-loaded platelets revealed that PAAmMAc particles increased membrane fluidity in platelets, which may be due to physicochemical interaction with PAAmMAc surfaces.

Acrylic Resins↗

Epstein-Barr virus-infected T lymphocytes in Epstein-Barr virus-associated hemophagocytic syndrome.

The clonal composition of EBV-infected cells was examined in three cases of EBV-associated hemophagocytic syndrome by analysis of the heterogeneity of terminal repetitive sequences in the EBV genome, indicating monoclonal expansion of EBV-infected cells in all cases. Involvement of T lymphoid cells was determined by in situ hybridization using 35S-labeled RNA probes specific for the small EBV-encoded nuclear RNAs, EBER1 and EBER2, in combination with immunostaining for the TCR-beta chain, CD45RO, CD20, CD30 and CD68 antigens in these three cases. The majority of lymphoid cells showing EBER transcripts were stained by antibodies against CD45RO and T cell receptor-beta. In contrast, EBER-specific signals were not detectable on B cells or hemophagocytic cells. These data support the concept that EBV-associated T cell proliferation is a primary feature of EBV-AHS.

Adolescent↗

[Projects in surgery for lung transplantation].

Lung transplantation was simulated in 9 essential items in the surgical side. The possibility to utilize cardiac death donor instead of cerebral death donor was discussed. The transplant window was shown in a patient with primary pulmonary hypertension. The informed consent must be authorized at the specific meeting. For the pre- and postoperative care, it is essential for surgeon to treat on the team which is consisted of members from the specific regions. With donation, a method of the standardization for graft preservation was shown by statistical analysis of many factors. The level of surgical techniques in Japan have been evaluated to be on the current level. In postoperative care, reimplantation response, infection, and rejection are important factors which have been clinically overcome in preceding institutions. However, a practical method of established diagnosis for acute rejection remain unresolved. In addition, CMV infection will be an unavoidable problem in Japan. The research of immune tolerance has been successfully underwent in experiments to overcome chronic rejection.

Humans↗

[Successful surgery for pulmonary aspergillosis progressing to subacute process].

A 59-year-old woman with diabetes and rheumatoid arthritis was given prednisolone following the diagnosis of rheumatoid lung disease. She developed fever and bloody sputum, and chest X-ray showed a massive shadow in the right lower lung field. Chest CT revealed a giant massive shadow with unclear margin in the right posterior lower lobe. With enhancement, a round low density area appeared in the shadow. Aspergillus hyphae were detected from a bronchial brushing specimen. Pulmonary aspergillosis was diagnosed administration of anti-fungal agents was commenced but the improvement was not satisfactory. Surgical resection, which may be curative, was subsequently performed. The resected lung contained an aspergillus ball formation within an enlarged bronchus, that is, a bronchial aspergilloma, surrounded by widespread inflammatory cell infiltration. Most pulmonary aspergillomas are of the "colonization type", but in our case progression to subacute process occurred according to the extent of our patient's immunological reaction. For the treatment of localized pulmonary aspergillosis, our results suggest that surgery is recommended.

Arthritis, Rheumatoid↗

[The dose-response study of sparfloxacin against skin and soft tissue structure infections in the field of surgery].

Sparfloxacin (SPFX), a new oral quinolone antimicrobial, was evaluated for the clinical efficacy against skin/soft tissue structural and osteomyelitic infections. SPFX was administered to a total of 101 patients with various infections such as infected atheroma, periproctal abscess, subcutaneous abscess, wound infections, felon, cellulitis, furuncle, pilonidal sinus, sappurative mastitis, lymphangitis, hemorrhoidal fistula, osteomyelitis. The clinical efficacy in the evaluable 101 cases was assessed by the physician in charge as excellent in 19 cases, good in 64, fair in 11 and poor in 7, the efficacy rate being 82.2%. In contrast, the clinical efficacy in 101 evaluable cases by the criteria of the committee as excellent in 36 cases, good in 45, fair in 8, and poor in 12, the efficacy rate being 80.2%. Clinical efficacy rating was not significantly difference between 200 mg/day group and 300 mg/day group. The bacteriological eradication rate was 86.5% in 53 cases with monomicrobial infection and 90.3% in 33 cases with polymicrobial infections. Of 18 cases whose infections were previously intractable with other drugs and treated thereafter with SPFX, 15 were judged in the efficacy as excellent or good. The side effects observed in 2 cases during the treatment were epigastralgia and nausea which were tolerable and did not require withdrawal of SPFX. No abnormal laboratory value was found in the several required tests. The MIC values measured for 108 strains (90.0%) of 120 clinical isolated of 35 species were lower than 0.78 microgram/ml.

Administration, Oral↗