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Biomedical subjects

M Kaji

Publications and source records attributed to M Kaji.

At least 73 records · Page 4Linked to original sources

The hydA gene encoding the H(2)-evolving hydrogenase of Clostridium perfringens: molecular characterization and expression of the gene.

A putative hydrogenase (hydA) gene of Clostridium perfringens encodes a protein with strong identity to Clostridium pasteurianum hydrogenase I. Disruption of the hydA gene abolished H(2) productivity, confirming its function. A putative butyrate kinase gene (buk) is adjacent to the hydA gene. When cultures were grown in medium with glucose, 1.8-kb hydA and 2.1-kb buk transcripts and a 3. 9-kb transcript hybridized with both hydA and buk-probe were detectable in all the exponential growth phases. In medium without glucose, these transcripts were decreased rapidly after the mid-exponential phase. These results suggest that the transcription of these two genes is probably regulated by a similar mechanism in response to glucose availability.

Bacterial Proteins↗

Retracted: Rapid diagnosis of cryptococcal meningitis by microscopic examination of centrifuged cerebrospinal fluid sediment.

The classic India ink test is positive in only half of cryptococcal meningitis cases, and reliable, rapid cryptococcal antigen (CRAG) testing requires technical expertise and facilities not always available. We therefore examined cerebrospinal fluid (CSF) sediment using May-Giemsa, periodic acid-Schiff, and Gram stains in 16 patients with cryptococcal meningitis. The India ink test was positive in seven patients (44%), while microscopic examination of sediment revealed cryptococci in 13 (81%); in six of these 13 the India ink test was negative. Both methods failed to detect the pathogen in the remaining three patients. CRAG testing in CSF was negative in two patients (one with acquired immunodeficiency syndrome, one with diabetes mellitus) whose India ink test also was negative while cryptococci were identified in their CSF sediment. No false positives occurred with CSF May-Giemsa staining in 27 cases of aseptic meningitis with negative cultures for Cryptococcus. In all, microscopic examination of centrifuged and stained CSF sediment proved more sensitive for rapid diagnosis of cryptococcal meningitis than the India ink method, and in two of our patients cryptococci were seen in centrifuged CSF sediment despite negative CRAG and India ink tests.

Adolescent↗

Preparation of High Yields of Algal Protoplasts Using Buccal Juice of Sea Hare and Commercial Cellulase.

; Buccal juice of the sea hare Aplysia juliana was found to degrade algal polysaccharides. The optimal enzyme composition for protoplast preparation from Undaria pinnatifida was protein at 48 µg/ml buccal juice from sea hare, 10 mg/ml cellulase Onozuka-RS, 0.4 M NaCl, 0.8 M sorbitol, 2 mg/ml dextran sulfate sodium salt, and 1 µl/ml 2-mercaptoethanol in 10 mM MES buffer (pH 6.0). Protoplasts of Eisenia bicyclis, Endarachne binghamiae (Phaeophyta), and Ulva pertusa (Chlorophyta) could also be prepared in a similar manner. Yields of these protoplasts were about 10(7) cells per gram of fresh weight alga.

Journal Article↗

Effect of immobilization upon renal synthesis of 1,25-dihydroxyvitamin D in disabled elderly stroke patients.

A 1,25-dihydroxyvitamin D [1,25-(OH)2D] deficiency and immobilization-related increased serum calcium concentration have been observed in hemiplegic stroke patients. To elucidate the influence of increased serum calcium concentration on bone metabolism, we measured serum biochemical indices and bone mineral density (BMD) in the second metacarpals of 170 elderly subjects with hemiplegic stroke and 72 age-matched healthy controls. Serum concentrations of 25-hydroxyvitamin D [25-(OH)D], 1,25-(OH)2D, ionized calcium, intact parathyroid hormone (PTH), intact bone Gla protein (BGP), and pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) were measured. An increased serum calcium concentration (mean 2.543 mEq/L) was observed in this population and correlated negatively with the Barthel index (mean 66), indicating immobilization-induced bone resorption with consequent increased serum calcium. Decreased serum concentrations of 1,25-(OH)2D (mean 25.0 pg/mL) and serum 25-OHD concentration (mean 11.6 ng/mL) were noted. Serum PTH was not increased (mean 34.8 pmol/L). Serum levels of BGP were decreased significantly, whereas serum ICTP concentrations were elevated (mean 15.2 ng/mL). A strong negative correlation was seen between the serum calcium concentration and 1,25-(OH)2D (p < 0.0001). BMD of the second metacarpal in patients was decreased significantly compared with control subjects and highly correlated with 25-(OH)D and 1,25-(OH)2D concentrations. Immobilization-related increased serum calcium levels may inhibit PTH secretion, and thus 1,25-(OH)2D production. In addition, 25-(OH)D insufficiency also may contribute to decreased concentration of 1,25-(OH)2D.

Absorptiometry, Photon↗

Smooth muscle tumors of the esophagus: clinicopathological findings in six patients.

Preoperatively, it is difficult to discriminate leiomyoma and leiomyosarcoma of the esophagus, which are rare smooth muscle tumors. The objective of this study was to evaluate the clinicopathological findings of this unusual lesion. A search of the surgery archives of the Toyama Prefectural Central Hospital of Pathology revealed six cases of esophageal smooth muscle tumors. Clinicopathological findings were reviewed retrospectively. Only three patients (50%) presented with dysphagia, and the remaining three patients were asymptomatic. These patients underwent surgical excision. Histologically four of the six tumors were leiomyomas, and the other two tumors were leiomyosarcomas. Two tumors were in the upper to middle esophagus, and the remaining four were in the distal esophagus. On endoscopic examination, all tumors were noted to be polypoid. The two leiomyosarcomas measured over 5 cm and the four leiomyomas less than 4 cm. Neither ulceration nor necrosis proved to be of use in discriminating leiomyoma and leiomyosarcoma. The two patients with leiomyosarcoma died of liver metastasis 10 and 22 months after the treatment. Patients with leiomyosarcoma presented with distant metastasis and/or recurrence, with hematogeneous metastasis being the predominant type of recurrence.

Adult↗

Number of lymph node metastases influences survival in patients with thoracic esophageal carcinoma: therapeutic value of radiation treatment for recurrence.

We retrospectively investigated whether the number of involved lymph nodes and the radiation therapy for recurrence affect survival in patients with thoracic esophageal carcinoma. Eighty-nine patients underwent surgical resection and reconstruction for thoracic esophageal squamous cell carcinoma beyond the mucosal layer. Patients were classified into three groups: group 1 comprised 40 patients without lymph node involvement; group 2 comprised 34 patients with 1-3 positive nodes; and group 3 comprised 15 patients with > or = 4 involved lymph nodes. The 3-year and 5-year survival rates were 77.5% and 73.2% respectively in group 1, 64.8% and 55.8% respectively in group 2, and 28.1% and 0% respectively in group 3. The mean survival time (MST) mean +/- SD of the patients in group 3 (772.1 +/- 146.2 days) was significantly shorter than that of patients in group 1 (3728.5 +/- 320.7 days, p < 0.0001) and group 2 (2330.4 +/- 344.3 days, p = 0.0130). The MST of the patients in group 2 was also significantly shorter than that of patients in group 1 (p = 0.0366). Patients with recurrent lymph nodes that were localized were treated effectively with radiation therapy. We conclude that the number of lymph node metastases influences survival in thoracic esophageal cancer. Early detection as well as radiation therapy for recurrent lymph node metastases is effective in improving long-term survival.

Adult↗

A Clostridium perfringens hem gene cluster contains a cysG(B) homologue that is involved in cobalamin biosynthesis.

The hem gene cluster, which consists of hemA, cysG(B), hemC, hemD, hemB, and hemL genes, and encodes enzymes involved in the biosynthetic pathway from glutamyl-tRNA to uroporphyrinogen III, has been identified by the cloning and sequencing of two overlapping DNA fragments from Clostridium perfringens NCTC8237. The deduced amino acid sequence of the N-terminal region of C. perfringens HemD is homologous to those reported for the C-terminal region of Salmonella typhimurium CysG and Clostridium josui HemD. C. perfringens CysG(B) is a predicted 220-residue protein which shows homology to the N-terminal region of S. typhimurium CysG. Disruption of the cysG(B) gene in C. perfringens strain 13 by homologous recombination reduced cobalamin (vitamin B12) levels by a factor of 200. When grown in vitamin B12-deficient medium, the mutant strain showed a four-fold increase in its doubling time compared with that of the wild-type strain, and this effect was counteracted by supplementing the medium with vitamin B12. These results suggest that C. perfringens CysG(B) is involved in the chelation of cobalt to precorrin II as suggested for the CysG(B) domain of S. typhimurium CysG, enabling the synthesis of cobalamin.

Base Sequence↗

Carpal tunnel syndrome involving unaffected limbs of stroke patients.

BACKGROUND AND PURPOSE: Stroke-induced hemiparesis involving the arm and hand results in regular, repeated overuse of the opposite hand and wrist. Because repetitive hand and wrist movement is a common cause of carpal tunnel syndrome (CTS), we examined the nonparetic upper limb in stroke patients for evidence of CTS. METHODS: We measured bilaterally sensory nerve conduction velocity (SNCV), motor nerve conduction velocity (MNCV), sensory nerve action potentials (SNAP) at the wrist, palm-to-wrist distal sensory latency (DSL), palm-to-wrist SNAP, compound motor action potentials (CMAP), and distal motor latency (DML) in stroke patients and control subjects. Controls were right-handed, >/=65 years old, lucid, independent in their activities of daily living, and had no disease known to cause CTS. Stroke patients were divided into a functioning hand group (n=61) and a disused hand group (n=71). All patients had hemiplegia. RESULTS: Tinel's sign was observed on the nonparetic side in 57.7% of patients with a disused hand and in 31.1% of those with a functioning hand. All electrophysiological indices were significantly more abnormal on the nonparetic side than on the hemiparetic side or in controls. Patients with a disused hand showed greater abnormality on the nonparetic side in SNCV, SNAP, palm-to-wrist DSL, DML, and CMAP than patients with a functioning hand. CONCLUSIONS: Overuse of the nonparetic hand and wrist of the nonparetic side may result in CTS in stroke patients, especially when the paretic hand is not functional. Wrist splinting or other prophylactic treatments beginning soon after stroke might help to prevent CTS.

Aged↗

[Coxsackie virus].

Explore the source record for details and available documents.

Antigens, Viral↗

Long-term benefits for the quality of life after video-assisted thoracoscopic lobectomy in patients with lung cancer.

Quality of life (QOL) after video-assisted thoracic surgical (VATS) lobectomy remains to be defined. Forty-four consecutive patients with clinical stage I lung cancer underwent lobectomy by the VATS approach (n = 22 patients) or thoracotomy approach (n = 22 patients). Acute pain was quantitated by postoperative narcotic requirements and the need for epidural anesthesia. Long-term QOL was assessed by questioning patients about the presence of chronic chest pain, ongoing limitations in arm or shoulder function, time until return to preoperative activity, and satisfaction with the operation. Patients who underwent VATS lobectomy had significant decreases in both acute and chronic chest pain and time until return to preoperative activity. Patients also had more confidence regarding wound size and their overall impression of the operation. In this series, VATS lobectomy was associated with long-term benefits for the QOL in patients with lung cancer. However, the exact role of this approach should be defined by carefully-designed controlled trials studying long-term survival.

Adult↗

The Ah receptor is not involved in 2,3,7,8-tetrachlorodibenzo- p-dioxin-mediated apoptosis in human leukemic T cell lines.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a common environmental pollutant causing public concern. Its toxic effects include disruption of the immune, endocrine, and reproductive systems, impairment of fetal development, carcinogenicity, and lethality in rodents. Here, we report that TCDD induces apoptosis in two cultured human leukemic lymphoblastic T cell lines. This cell death was found not to be dependent on an aryl hydrocarbon receptor and to be inhibited by the inhibitor of tyrosine kinases and caspases. Apoptosis-linked c-Jun N-terminal kinase is rapidly activated in these cells by the treatment with TCDD. A dominant-negative mutant of c-Jun N-terminal kinase prevented cell death in the treatment with TCDD. Furthermore, TCDD decreases the Bcl-2 protein level in these cell lines. These findings will help in the understanding of the molecular mechanism underlying TCDD-mediated immunotoxicity.

Apoptosis↗