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Biomedical subjects

H Kawai

Publications and source records attributed to H Kawai.

At least 19 recordsLinked to original sources

Enhancement of aromatic amino acid-nucleic acid base stacking interaction by metal coordination to base: fluorescence study on a tryptophan-Pt(II)-guanine ternary complex.

In order to investigate the effect of the Pt(II) ion on the stacking interaction between tryptophan and a guanine base, the quenching of Trp fluorescence was monitored for some systems in the absence and presence of the metal ion, and the association constants were obtained by the analysis of Eadie-Hofstee plots. All spectral data suggested that the stacking interaction is enhanced by the Pt(II) coordination to the guanine N7 atom. The result indicates the importance of the metal ion as a bookmark in the specific recognition of a nucleic acid base by an aromatic amino acid residue.

Base Composition

Aspartate-based inhibitor of interleukin-1 beta-converting enzyme prevents antitumor agent-induced apoptosis in human myeloid leukemia U937 cells.

We found that a novel protease inhibitor, benzyloxycarbonyl-Asp-CH2OC(O)-2,6-dichlorobenzene (Z-Asp-CH2-DCB), which can preferentially inhibit interleukin-1 beta-converting enzyme (ICE), completely blocked the apoptotic cell death of human myeloid leukemia U937 cells caused by etoposide, camptothecin, 1-beta-D-arabinofuranosyl-cytosine and Adriamycin, as well as TNF-alpha, anti-Fas antibody and staurosporine. However, Z-Asp-CH2-DCB did not block non-apoptotic cell death of U937 cells caused by etoposide during prolonged incubation periods. These results indicate that ICE or ICE-like proteases inhibited by Z-Asp-CH2-DCB are involved in a common pathway of apoptotic cell death in U937 cells.

Antineoplastic Agents

Oligomannose-coated liposomes as an adjuvant for the induction of cell-mediated immunity.

The effect of the coating of ovalbumin-reconstituted liposomes with various oligosaccharides on their immunogenicity was investigated in mice. The coating of liposomes with oligomannose or yeast mannan drastically enhanced their ability to induce an ovalbumin-specific delayed-type footpad swelling response with a peak at 24 to 48 h post-challenge. Among various oligosaccharides tested, only those with mannose residue at the nonreducing termini manifested the activity when applied to liposomes. Since such oligosaccharides are ubiquitously found in the body, these results suggested the usefulness of oligomannose-coated liposomes as a safe adjuvant for the induction of cell-mediated immunity.

Adjuvants, Immunologic

Presence of human T-lymphotropic virus type II-related genes in DNA of peripheral leukocytes from patients with autoimmune thyroid diseases.

No etiologic role of human T-lymphotropic virus type II (HTLV-II) in any disease is yet known. The present study showed a high incidence of HTLV-II proviral DNA fragments in DNA of peripheral blood leukocytes from patients with autoimmune thyroid diseases. Using primers for the pol and tax regions of HTLV-II proviral DNA, amplified DNA fragments were demonstrated in 51.5% of the patients with Hashimoto's thyroiditis and in 11.8% of those with Graves' disease examined, but in only 1.9% of the disease controls and 1.0% of healthy individuals. These amplified DNA fragments hybridized with each of the inner probes. The nucleotide sequences of the DNA fragments of the pol and tax regions showed high homology with those of the prototype of HTLV-II. No antibodies for HTLV-II could, however, be detected in the patients examined. Because of the absence of its antibody, HTLV-II infection was not confirmed in these patients, but the presence of HTLV-II proviral DNA or its related DNA at high frequency suggests a relationship of HTLV-II with the development of autoimmune thyroid diseases.

Adult

Mitochondrial encephalomyopathy with autosomal dominant inheritance: a clinical and genetic entity of mitochondrial diseases.

We report a Japanese family with chronic progressive external ophthalmoplegia (CPEO) with autosomal dominant inheritance, and review 54 reported CPEO patients in seven families (including the present family) with autosomal dominant inheritance and mtDNA deletions in the skeletal muscle. Mean age at onset in the CPEO was 26 years, which is older than that in published solitary cases. In addition to blepharoptosis and external opthalmoplegia, proximal muscle atrophy and weakness were found in 62%, hearing loss in 25%, and ataxia in 17% of the patients. Retinal degeneration was not found, and cardiac involvement was very rare. mtDNA deletions in the muscle were multiple and large scale, and all such deletions were located in the non-D-loop region. Autosomal dominant CPEO has unique clinical features which differ from those of solitary CPEO, and is associated with multiple large-scale mtDNA deletions. Thus, autosomal dominant CPEO can be considered a clinical and genetic entity of mitochondrial diseases.

Base Sequence

Lysosomal enzyme activities in skeletal muscle of patients with neuromuscular diseases.

Activities of nine lysosomal enzymes and pH-dependent isozyme patterns of alpha-mannosidase were examined in the skeletal muscle of patients with neuromuscular diseases, and the ratios of these enzyme activities in leukocytes to those in myocytes (L/M ratio) were determined. The activities of enzymes with a high L/M ratio were markedly increased in the muscles of patients with Duchenne muscular dystrophy (DMD), myotonic dystrophy (MyD), or polymyositis (PM). In contrast, those which showed a low L/M ratio were increased in the muscles of amyotrophic lateral sclerosis (ALS) and disuse muscle atrophy (DUA). The isozyme pattern of alpha-mannosidase in DMD muscle resembled that in leukocytes, while those in ALS and DUA muscle resembled that in normal muscle. These results may suggest that the increased activity of lysosomal enzymes in the muscles of patients with DMD, MyD, or PM is due primarily to infiltrating leukocytes, while that in patients with ALS or DUA is due to intramyofiber lysosomes.

Aged

Graves' disease in HTLV-I carriers.

Three carriers of human T-lymphotropic virus type I (HTLV-I) with Graves' disease are reported. All three cases were complicated with uveitis, and one also showed chronic arthropathy. Anti-HLTV-I antibody was found in the serum by the particle agglutination method and western blotting, and HTLV-I proviral DNA was detected in peripheral lymphocytes by the polymerase chain reaction and Southern blotting. HTLV-I is a causal agent of adult T-cell leukemia and HTLV-I associated myelopathy/tropical spastic paraparesis, and is believed to be related to the pathogenesis of diseases such as chronic arthropathy, uveitis, chronic bronchoalveolitis, and Sjögren's syndrome. On the other hand, retrovirus infection is considered to cause autoimmune diseases. Thus, the pathogenesis of Graves' disease in the present patients might be associated with HTLV-I infection.

Aged

Anterior wedge-shaped bone graft for old scaphoid fractures or non-unions. An analysis of relevant carpal alignment.

For appraisal of anterior wedge-shaped grafts for the humpback deformity of the scaphoid, a retrospective study of 27 cases with old scaphoid fractures or non-unions was carried out. 11 cases were treated with Herbert screw fixation and anterior wedge-shaped graft and the other cases with other methods. For the assessment of carpal alignment, radio-lunate and scapho-lunate angles were measured with peri-operative radiographs. For the clinical assessment, the scoring system of Cooney was applied. In 25 cases, primary bone union was obtained with one attempt and in two cases, with the second operation. Union was achieved in a mean of 3.4 months. The post-operative wrist score ranged from 65 to 100 with an average 81.2 points. There was a statistically significant relationship between the wrist score and the post-operative scapho-lunate angulation of the affected wrist. The humpback deformity of scaphoid non-union should be treated precisely with carpal realignment surgery or anterior wedge-shaped bone graft.

Adolescent

Adhalin gene mutations in patients with autosomal recessive childhood onset muscular dystrophy with adhalin deficiency.

Homozygous adhalin gene mutations were found in three patients from two consanguineous families with autosomal recessive childhood onset muscular dystrophy. Muscle biopsies from patients in each family showed complete absence of adhalin. Sequencing of adhalin cDNA prepared from skeletal muscle by reverse transcription PCR demonstrated a cytosine to thymidine substitution at nt 229 in the patient in family 1 and an adenine to guanine substitution at nt 410 and a 15-base insertion between nt 408 and 409 in the two patients in family 2. Sequencing of genomic DNA prepared from peripheral blood leukocytes by PCR confirmed these mutations. The parents in each family were found to be heterozygous for the respective mutations. These adhalin gene mutations are presumed to be responsible for the absence of adhalin in the skeletal muscle. Adhalin deficiency likely causes disruption of the muscle cell membrane, resulting in dystrophic changes in the skeletal muscle similar to dystrophin deficiency in Duchenne muscular dystrophy.

Adult

Inhibitory effect of clopidogrel, vapiprost and argatroban on the middle cerebral artery thrombosis in the rat.

This study investigated the roles of thromboxane A2 (TXA2), ADP and thrombin in middle cerebral artery (MCA) thrombosis in the rat. The rat MCA was occluded by a thrombus induced by the photochemical reaction of rose bengal by green light that causes endothelial damage followed by platelet adhesion, aggregation and formation of a platelet and fibrin-rich thrombus at the site of the photochemical reaction. Vapiprost, a specific TXA2-receptor antagonist; clopidogrel, which has the thienopyridine structure of ticlopidine and is a more potent inhibitor of ADP-induced platelet aggregation than ticlopidine; argatroban, a specific thrombin inhibitor; or heparin was administered intravenously before rose bengal injection. The MCA local blood flow was monitored by a laser Doppler flowmeter. The MCA was occluded by thrombus about 5 min after the initiation of the photochemical reaction. Vapiprost, clopidogrel and argatroban all significantly prolonged the time taken for the thrombotic occlusion of the MCA, but in this respect, heparin was ineffective. Our observations suggest that vapiprost and clopidogrel are useful antithrombotic agents against platelet and fibrin-rich thrombi. The effect of argatroban is attributable to inhibition of thrombin-induced platelet activation and fibrin generation. The thrombosis model described in this study is useful for understanding the mechanism(s) of thrombogenesis in the rat MCA and may be applied to other mammalian species.

Animals

Pneumatosis cystoides intestinalis after chemotherapy for hematological malignancies: report of 4 cases.

Pneumatosis cystoides intestinalis (PCI) is known to be a relatively rare condition which is characterized by gas cysts in the gastrointestinal mucosa. We treated four cases of PCI accompanied by hematological malignancies during chemotherapy treatment. All cases suffered from abdominal discomfort. Abdominal X-ray films revealed gas cysts in the intestine. PCI was observed during leukocytopenic states, and three cases had septicemia. Etoposide was administered to three cases, and prednisolone to all cases. It is considered that PCI sometimes occurs in patients with hematological malignancies during a period of leukocytopenia, and may be caused by intestinal mucosal damage due to myelosuppressive agents and immunosuppression from prednisolone.

Adult

Synthesis and antitumor activities of glycine-exchanged analogs of spicamycin.

A series of SPM VIII analogs were synthesized to investigate the effect of the amino acid moiety on the antitumor activity. The L-threonine analog and the glycylglycine analog of SPM VIII showed much higher cytotoxicity to P388 murine leukemia cells (IC50 5.8 nM and 0.11 nM, respectively) than SPM VIII (IC50 25nM). However, replacement of the glycine moiety with other amino acids greatly reduced the antitumor activity against COL-1 human colon cancer xenograft model. This study indicated that the glycine moiety of SPM VIII is crucial for the antitumor effect.

Amino Acids

[Clinical analysis of 14 patients with anti-myeloperoxidase antibody positive rapid progressive glomerulonephritic syndrome].

We investigated the clinical features and outcome of 14 patients with anti-myeloperoxidase antibody (MPO-ANCA) positive rapidly progressive glomerulonephritic syndrome. Underlying diseases included microscopic polyarteritis in 6 patients, idiopathic crescentic glomerulonephritis with lung hemorrhage in 2 patients, idiopathic glomerulonephritis in 3 patients, rapidly progressive glomerulonephritic syndrome without renal biopsy in 1 patient, crescentic glomerulonephritis associated with Sjögren syndrome and progressive systemic sclerosis in 1 patient and crescentic glomerulonephritis associated with sarcoidosis in 1 patient. Five patients were male (mean age, 59.2 years) and 9 were female (mean age, 54.0 years). On admission, most patients had anemia, leukocytophilia, and marked elevation of C-reactive protein (CRP). Average hemoglobin, white blood cell count and CRP levels on admission were 8.1 mg/dl, 11,500/mm3 and 14.7 mg/dl, respectively. Average serum creatinine was 4.0 mg/dl. All patients were treated with steroids either with or without cyclophosphamide. As the patients recovered clinically, the MPO-ANCA titers declined. Although most patients responded well to immunosuppressive therapy, some died of serious complications (such as acute respiratory distress syndrome, fungal infection, and pneumocystis pneumonia). The prognosis of patients with severe renal failure was especially poor. We conclude that early diagnosis, treatment and intensive care during immunosuppressive therapy are very important in the management of MPO-ANCA-positive rapidly progressive glomerulonephritis.

Adolescent

[A case of primary pulmonary hemangiopericytoma recurred locally 10 years after the first surgery].

Hemangiopericytoma is a rare tumor of vascular origin. This tumor has a malignant potential and often recurs or metastasize. A case of primary pulmonary hemangiopericytoma which recurred locally 10 years after the first surgery is presented. The histological appearance of the tumor had some findings of malignant potential in both of the primary and recurrent lesions. We discussed on malignant potential of this tumor in the number of mitotic figures, cellular atipia, and DNA ploidy pattern.

Female

[The influence of electrical time interval indices and aging on the left atrial systolic time intervals].

The influence of aging and heart rate on left ventricular systolic time intervals is well known, but the effects on left atrial systolic time intervals, a new index of left atrial function, remain unknown. The influence of aging and heart rate on left atrial systolic time intervals was investigated in 43 normal subjects (13-72 years of age) by Doppler echocardiography. Atrial pre-ejection period, atrial ejection time, and corrected atrial pre-ejection period were obtained by transmitral Doppler echocardiography. Simple regression analysis showed atrial pre-ejection period significantly correlated with P wave duration (PP; r = 0.78), and PR interval (PR; r = 0.60), but not with RR interval (RR). However, multiple regression analysis showed atrial pre-ejection period significantly correlated only with PP. Simple regression analysis found atrial ejection time significantly correlated with PP (r = 0.38), and PR (r = 0.39), but not with RR. However, multiple regression analysis found atrial ejection time did not correlate with any factor significantly. Aging was significantly correlated with corrected atrial pre-ejection period (r = -0.37), but not with corrected atrial ejection time and atrial pre-ejection period. Atrial ejection time significantly correlated with corrected atrial pre-ejection period (r = -0.37), but not with atrial pre-ejection period. Corrected atrial pre-ejection period is a clinically useful index of left atrial systolic function.

Adolescent

[Complete deficiency of adhalin (50 kDa DAG) in skeletal muscle of malignant limb-girdle muscular dystrophy].

Malignant limb-girdle muscular dystrophy was first described by Miyoshi and co-workers in 1966, and has clinical features similar to Duchenne muscular dystrophy but is inherited through an autosomal recessive trait. This paper describes a patient with malignant limb-girdle muscular dystrophy with complete deficiency of adhalin (50 kDa dystrophin-associated glycoprotein (DAG)) in skeletal muscle. The patient was an 11-year-old Japanese girl whose parents were cousin. She learned to walk at one year and 3 months of age. Her gait became unsteady at 3 years of age, and motor dysfunction in the lower extremities progressed thereafter. At 8 years of age, she had difficulty in standing up from a sitting position, but could walk without assistance. At 11 years, she could walk with support, but could not stand up without assistance. Her intelligence was normal. Muscle atrophy was not apparent due to obesity, but her calves appeared hypertrophic. She had generalized muscle weakness, predominantly in the pelvic girdle muscle. Muscle tone was slightly hypotonic, and deep tendon reflexes of the legs were absent or hypoactive. Her sensory system appeared normal. Serum creatine kinase level was elevated to 30 times above the upper limit of the normal range in the patient and normal in her parents. EMG showed a mild myopathic pattern. CT scan of muscle revealed marked low density in the upper legs and mild in the lower legs. Muscle histology showed muscle fiber necrosis with a small number of regenerating fibers. Opaque fibers were occasionally observed, but not as many as in Duchenne type. Fiber splitting was seen frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

Child