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Biomedical subjects

M Kuroda

Publications and source records attributed to M Kuroda.

At least 271 records · Page 15Linked to original sources
PubMed1994

Transcriptional attenuation and differential mRNA stability in the regulation of the Escherichia coli melibiose operon.

The organization of the melibiose operon of Escherichia coli is promoter-melA-melB. The amount of the product (alpha-galactosidase) of the first gene (melA) is much larger than that of the product (melibiose permease) of the second gene (melB). Using the chloramphenicol acetyltransferase gene (cat) as reporter, we found that there was an element between melA and melB, which reduced the expression of the downstream gene, melB. This region contained a boxA-like sequence, which is known as a binding site for an attenuation factor, NusA. Northern hybridization analysis revealed that the ratio of melA mRNA and melAB mRNA was comparable with the ratio of the melA and melB products. We also found that the melA mRNA was about 3-fold more stable than the melAB mRNA. Experimental results obtained with a nusAts mutant suggested that the NusA protein is involved in the reduced expression of the melB gene. We conclude that the production ratio of alpha-galactosidase and melibiose permease is regulated at two levels: 1) transcription and 2) mRNA stability.

Base Sequence↗
PubMed1994

Characterization of mouse monoclonal antibody B1.4 reactive with human invasive bladder cancer and some other malignant tumors but not with normal urinary epithelium.

Immunohistochemical analysis by indirect immunoperoxidase staining demonstrated that monoclonal antibody (mAb) B1.4 derived from a mouse immunized with a bladder cancer cell line EJ-1 was reactive with a high proportion of high-grade and invasive bladder tumors, but not with the majority of low-grade and superficial bladder tumors, or normal urinary epithelium. Among 71 primary bladder tumors classified by pathological grading, positive stainings were observed in 1 of 34 tumors (3%) of grade 1, 8 of 20 tumors (40%) of grade 2 and 14 of 17 tumors (82%) of grade 3. When the tumors were classified by pathological staging, positive stainings were observed in only 8 of 54 (15%) superficial tumors of stages Ta and T1, but in 15 of 17 (88%) invasive tumors of stages T2 and T3. mAb B1.4 showed restricted positive stainings with normal tissues including renal glomerulus, vascular endothelium, squamous epithelium of esophagus, glandular epithelium of prostate, and epithelium of pancreatic acinar gland and minute duct, while positive stainings were observed in a range of tumor tissues other than bladder tumor. Mixed hemadsorption assays with a panel of cell cultures showed also that the antigen recognized by mAb B1.4 was expressed on a range of tumor cell lines. These findings suggest that the antigen recognized by mAb B1.4 may appear after malignant transformation, and be an indicator of malignant potential of bladder cancer.

Animals↗
PubMed1994

Giant cell tumor of the lung: an autopsy case report with immunohistochemical observations.

Tumors resembling giant cell tumor (GCT) of bone are well known to occur in other organs and many cases have been reported to date. While GCT occurring as primary lesions in the lung are extremely rare, the authors experienced such a tumor at an autopsy of a 77 year old woman and subsequently performed histological and immunohistochemical examinations. The clinical and morphologic characteristics of this case are documented, and the literature concerning this type of tumor is reviewed. The present tumor of the lung was histologically characterized by proliferation of benign-looking osteoclast-like giant cells in association with slightly atypical mononuclear cells. The tumor cells were immunohistochemically positive for histiocytic markers but negative for epithelial markers. This case appears to be the first reported benign giant cell tumor of the lung in which histiocytic differentiation of mononuclear cells was suggested by immunohistochemistry.

Aged↗
PubMed1994

Rapid dipstick test for diagnosis of urinary tract infection.

The rapid dipstick test of urine leukocyte esterase (LE) activity and nitrite has not been studied fully in pediatric clinical situations. We investigated the usefulness of the dipstick LE and nitrite test in the screening of urinary tract infection (UTI) in pediatric patients. Ninety-two fresh urine samples were obtained from children suspected of having UTI. Leukocyte esterase activity and nitrite were measured in the urine specimens read by a photometer. Leukocytes were also counted on a disposable slide. Urine samples were examined for bacteriuria by the standard culture method. The results of the urine dipstick test of LE showed a close relationship with leukocyte counts on a counting chamber. Leukocyte esterase (-) indicated leukocyte counts of less than 10/uL with a probability of 97% (58/60). Of the 22 urine samples with significant bacteriuria diagnosed by standard urine culture, the nitrite test did not detect bacteriuria in 10. While the sensitivities of the dipstick tests of nitrite (+) and LE +/- or more for the diagnosis of significant bacteriuria were 55% (12/22) and 86% (19/22), respectively, the sensitivity and negative predictive value of the combined test were 100%. These results suggest that use of the dipstick test of LE and nitrite can avoid a large part of the cost incurred by urine culture and is useful for screening UTI in children.

Adolescent↗
PubMed1994

Molecular cloning of two new heat shock genes related to the hsp70 genes in Staphylococcus aureus.

We have identified two new heat shock protein genes, orf37 and orf35, in Staphylococcus aureus, located upstream and downstream of grpE(hsp20), dnaK(hsp70), and dnaJ(hsp40) homologous genes in the order orf37-hsp20-hsp70-hsp40-orf35. The transcripts of both orf37 and orf35 were increased by thermal upshift of the culture from 37 to 46 degrees C. The heat shock promoters were located upstream of orf37 and upstream of hsp40. The deduced peptide of orf37 showed similarity with those of orfA in Clostridium acetobutylicum and orf39 in Bacillus subtilis. orf35 was unique in S. aureus and has not yet been described in other bacteria.

Amino Acid Sequence↗
PubMed1994

Lanosterol oligosaccharides from the plants of the subfamily Scilloideae and their antitumor-promoter activity.

Phytochemical studies of the bulbs of Scilla peruviana, Eucomis bicolor, Chionodoxa gigantea and C. luciliae gave respectively two new and two known, four new and two known, three known, and one new and five known lanosterol oligosaccharides. The structures of the new compounds were determined from spectroscopic data. A total of 19 lanosterols, including previously isolated compounds, were examined for inhibitory activity on 12-O-tetradecanoylphorbol 13-acetate (TPA)-stimulated 32P incorporation into phospholipids of HeLa cells as the primary screening test to find new antitumor-promoter compounds.

Anticarcinogenic Agents↗
PubMed1994

A new capacitive heating applicator for the simultaneous radiohyperthermotherapy of superficial and shallow-seated tumors.

External capacitive heating is the usual method of electromagnetic wave heating, in which the tumor is caught and heated between two opposite applicators. Using a phantom, the authors developed and evaluated the performance of a new capacitive heating applicator designed for simultaneous radiohyperthermotherapy (SRH) in which the electron beam irradiation is provided from above an external capacitive heating applicator for the treatment of superficial and shallow-seated tumors. The trial applicator was constructed to fulfill the following conditions: 1. use of an electrode plate which does not affect the electron beam depth dose, 2. a uniform thickness to maintain flatness of the electron beam, and 3. a cooling function to prevent damage to normal skin tissue and enhance the therapeutic gain factor. This applicator was comprised of a 0.1-mm-thick copper electrode and a 5-mm-thick cooling chamber. The depth of the 80% dose of the new applicator was 21 mm with a 9-MeV electron beam and 36mm with a 15-MeV electron beam, which was comparable to the effect of a conventional irradiation bolus. The temperature distribution produced by the trial applicator was symmetrical on both sides from the center of the applicator. The 50% specific absorption rate region was 6.4 cm wide at a depth of 1 cm from the phantom surface and 2.8 cm wide at a depth of 3 cm. There have been no previous reports on the development of an external capacitive heating applicator designed for the SRH of superficial and shallow-seated tumors; this is the first such report.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined Modality Therapy↗
PubMed1994

Hand-arm vibration exposure and the development of vibration syndrome.

To evaluate the circulatory disturbances, sensory disturbances and damage to muscles and joints by chain saw vibration exposure, the process of the deterioration of the symptoms with chain saw operating time was studied. Subjects were classified into eight groups according to TOT (Total Operating Time): Group 0, 46 controls; Group A, 39 operators (< 2,000 hours); Group B, 53 operators (2,000-4,000 hours); Group C, 45 operators (4,000-6,000 hours); Group D, 29 operators (6,000-8,000 hours); Group E, 31 operators (8,000-10,000 hours); Group F, 35 operators (10,000-15,000 hours); and Group G, 34 operators (> 15,000 hours). The subjective symptoms and clinical findings due to operating chain saws were divided into three main categories of peripheral circulatory disturbances, sensory disturbances and damage to muscles and joints. According to the criteria, the total score of each disturbance was calculated per individual in Group 0 and Groups A through G, respectively. The scores for the three (circulatory, sensory, muscles and joints) disturbances increased significantly with the increase of TOT. The scores for circulatory disturbances increased significantly in Group A and B, as compared with those in its previous Group, respectively. The scores for sensory disturbances increased significantly in Groups A, B, and F. The scores for damage to muscles and joints increased significantly in Group B.

Arm↗
PubMed1994

[Effect of sevoflurane on blood flow velocity in the vertebral artery].

Blood flow velocity in the vertebral artery was measured using transcranial Doppler sonography during sevoflurane anesthesia in 12 patients in the knee-chest position. The correlation between mean arterial blood pressure (MBP) and mean blood flow velocity in the vertebral artery (Vmean) was significant in each patient. Normalized data expressed as a percentage of the individual arithmetic means permitted a composite analysis of data from all patients. Linear regression of normalized MBP (%MBP) on normalized Vmean (%Vmean) showed %Vmean = 24.8 +/- 0.75 %MBP (r = 0.78, P < 0.01). The results of the present study suggest that fluctuations in systemic blood pressure may lead to fluctuations in cerebral blood flow. Therefore, the use of sevoflurane anesthesia must be accompanied by careful management of blood pressure during surgery.

Adult↗
PubMed1994

Conformation of tetragastrin in DMSO. Monte Carlo simulation taking account of solvent effects.

A conformation analysis of tetrapeptide in DMSO was carried out by the Monte Carlo simulation including the solvent effects in the energy function. The lowest energy conformations in the zwitterionic and cationic states are a similar compact form, in which the two aromatic rings are close to each other. The distance distributions between the specified atoms in the molecule show that most conformations in the local energy minima are similar to this folded conformation, although there is another type of conformation of interest, which has an extended form with the two separate aromatic rings. Such results are consistent with the NMR and CD experiments, and suggest that the compact form of tetragastrin is essential as a biological active conformation. The folded structure is stabilized by the solute-solvent interaction. In particular, the nonbonding interactions between the solute and solvent molecules cause a folding effect on the molecular conformation in total. This study is a first case taking account of the solvent effect into the conformation analysis of tetragastrin.

Amino Acid Sequence↗
PubMed1994

[Two cases of asymptomatic primary biliary cirrhosis (PBC) accompanied with CREST syndrome].

Two cases of asymptomatic primary biliary cirrhosis (PBC) combining CREST syndrome. We have had encountered two primary biliary cirrhosis (PBC) patients overlapped with CREST syndrome. Case 1 was a 51-year-old female, who was suffering from Raynaud's phenomenon, esophageal dysmotility and sclerodactyly. Case 2 was a 67-year-old female, who was suffering from Raynaud's phenomenon, esophageal dysmotility, sclerodactyly and telangiectasia. They were free from itching and icterus. The histology of their biopsied liver specimen should stage I-II of Scheuer's classification. Their immunological findings showed anti-centromere antibody, (ACA) at a high titer (1 : 1280 dilution) and anti-mitochondrial antibody (AMA) at a low titer (1 : 40 dilution) positive in both. HLA DR types included DR2 and DRW8 in case 1, and did DR1 and DRW6 in case 2. Both patients are having good prognosis.

Aged↗
PubMed1994

[Neoadjuvant and adjuvant chemotherapy of bladder cancer].

Conventional treatments such as surgery and radiotherapy for deeply invasive, clinically non-metastatic bladder cancer are associated with cure in less than 30% of cases. This has led to the search for new approaches to therapy. Based on the excellent results with combination chemotherapy such as M-VAC in patients with advanced disease, neoadjuvant or adjuvant chemotherapy has been advocated to improve survival. Twenty patients with primary invasive bladder cancer who underwent radical cystectomy received postoperative adjuvant chemotherapy using a CAP (cyclophosphamide, doxorubicin and cisplatin) or modified M-VAC (methotrexate, vinblastine, pirarubicin and cisplatin) regimen. Sixteen of the patients were treated with CAP and four with the modified M-VAC. Of the 20 patients, 17 had transitional cell carcinoma with or without non-transitional cell elements. All of the patients had tumors with a histological grade of G2 (six cases) or G3 (14 cases). As for lymph node metastasis, there were 10 N0 cases, three N1 cases, six N2 cases, and one N3 case. The five-year survival rate of these 20 patients was 65.9%, while that of 49 patients not administered any adjuvant chemotherapy was 29.9%. Regarding toxicity, both adjuvant chemotherapy regimens in this study were generally well tolerated. The most common toxic effects were gastrointestinal symptoms, alopecia and myelosuppression. Twenty other patients with invasive transitional cell carcinoma of the bladder received two or three cycles of neoadjuvant chemotherapy using the modified M-VAC or MEC (methotrexate, epirubicin and cisplatin) regimen prior to radical cystectomy or partial cystectomy. Of 19 evaluable patients who received neoadjuvant chemotherapy, a complete response was observed in two (10%), a partial response in 11 (55%), and no change in six (30%). The overall response rate was 65%. The five-year survival rate of 20 patients who received neoadjuvant chemotherapy was 74.2%. Regarding toxicity, one patient died of a bowel complication after surgery, and the complication was suggested to be drug-induced.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

[Cause of hypotension during spinal anesthesia--the relation between the level of anesthesia and the hypotension].

A retrospective study was conducted on the cause of hypotension during spinal anesthesia and also on the relation between the level of anesthesia and the hypotension. Two hundred twenty three patients who had received spinal anesthesia for gynecological surgery were divided into two groups. Group I consisted of 87 patients with a significant decrease in blood pressure, while group II consisted of 136 patients with no significant decrease in blood pressure. First, the age, dosage of spinal anesthesia, amount of preoperative transfusion, and level of spinal anesthesia were reviewed and compared between the group I and II. Next, all the patients were classified by the level of spinal anesthesia, and the degree of decrease in blood pressure and the frequency of a significant decrease in blood pressure were examined by each level of spinal anesthesia. Only the level of spinal anesthesia was found to differ significantly between the group I and II. The degree of hypotension was greater at higher levels of spinal anesthesia. More than 50% of the patients with T5 or higher levels of anesthesia had a significant decrease in blood pressure. We conclude that the cause of the significant decrease in blood pressure during high spinal anesthesia is in most part due to the blockade of the cardiac sympathetic nerve.

Adult↗
PubMed1994

[Evidence for the existence of L-dopa-immunoreactive neurons in the human mesencephalic region].

The existence of L-3,4-dihydroxyphenylalanine (L-DOPA) immunoreactivity is demonstrated for the first time in some neurons in the human mesencephalic region, using an immunohistochemical method with a newly raised, highly specific anti-L-DOPA antiserum. In this study, we have found many L-DOPA-positive/dopamine (DA)-positive neurons. On the other hand, we observed a few L-DOPA-positive/DA-negative cell bodies in the dopaminergic regions in the midbrain. The present results suggest the possibility of the existence of more than one neuronal group in the human mesencephalic ventral tegmental area region. L-DOPA in one group is an intermediate metabolite for decarboxylation to DA and in another group may exist as an end-product. L-DOPA in the latter group could be a neuromodulator and/or neurotransmitter. Thus, we suggest that L-DOPA plays an important role besides being an intermediate of DA in the human mesencephalon.

Antibody Specificity↗
PubMed1994

[A case of intermittent Wolff-Parkinson-White syndrome caused by high spinal anesthesia].

We experienced a case of intermittent Wolff-Parkinson-White (WPW) syndrome following spinal anesthesia. This patient had neither any past history of cardiac symptoms nor any abnormal finding in the preoperative electrocardiogram. Soon after spinal anesthesia, the level of anesthesia spread to C6. Both abbreviated PR intervals and delta waves characteristic of WPW syndrome appeared on the electrocardiogram monitor. These abnormal wave-forms continued throughout the operation, but disappeared after three days. This case was diagnosed as intermittent WPW syndrome based upon these observations. High spinal anesthesia effectively blocks the cardiac sympathetic nerve and suppresses the normal atrioventricular conduction. Further, conduction by the accessory pathway is facilitated by the relative excitement of parasympathetic nerve. In the present case, the conduction by the accessory pathway, which had originally been very poor, was transiently promoted by the above-mentioned mechanism, and abnormal wave-forms characteristic of WPW syndrome appeared temporarily in the electrocardiogram.

Adult↗
PubMed1993

Identification of L-dopa immunoreactivity in some neurons in the human mesencephalic region: a novel dopa neuron group?

The presence of L-3,4-dihydroxyphenylalanine (L-DOPA) immunoreactivity is reported for the first time in some neurons in the human mesencephalic region, using an immunohistochemical method with a newly raised, highly specific anti-L-DOPA antiserum. We have found many L-DOPA-positive/dopamine (DA)-positive and a few L-DOPA-positive/DA-negative cell bodies in dopaminergic regions in the midbrain. The present results suggest the existence of more than one neuronal group of L-DOPA in the human mesencephalon. L-DOPA in one group is an intermediate metabolite for decarboxylation to DA and in another group may exist as an end-product. L-DOPA in the latter neurons could be a neuromodulator and/or neurotransmitter. Thus, we suggest that L-DOPA plays an important role besides being an intermediate of DA in the human mesencephalon.

Dopamine↗