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Biomedical subjects

M Kuroda

Publications and source records attributed to M Kuroda.

At least 289 records · Page 16Linked to original sources
PubMed1993

Molecular characterization of the gene operon of heat shock proteins HSP60 and HSP10 in methicillin-resistant Staphylococcus aureus.

Methicillin-resistance of S.aureus (MRSA) was diminished or depressed at 44 degrees C. In order to investigate whether bacterial heat shock response is correlated with methicillin resistance, we examined the inducibility of the heat shock proteins (HSPs) in MRSA, and cloned and sequenced of their genes. A temperature shift from 37 degrees C to 46 degrees C enhanced the production of at least 8 kinds of cytoplasmic proteins as measured with two-dimensional PAGE. The induced protein profile was almost the same as methicillin sensitive S.aureus, and stress conditions due to ethanol, cadmium or low pH. Two of these proteins were HSP60 and HSP10. Their N-terminal amino acid sequences were 79%, and 83%, homologous with thermobacterium PS3, respectively. A positively hybridized 4.2 kbp DNA fragment encoding both proteins was isolated from the chromosomal DNA of MRSA. The resulting sequence revealed two reading frames and showed high homology to those of hsp60 (groEL) and hsp10 (groES) of bacteria (E.coli) and several other species. The genes of HSP60 and HSP10 in S.aureus comprised an operon as in E.coli. The relationship between those HSPs and PBP2' is currently under investigation.

Amino Acid Sequence↗
PubMed1993

Direct synaptic connections between thalamocortical axon terminals from the mediodorsal thalamic nucleus (MD) and corticothalamic neurons to MD in the prefrontal cortex.

A combined anterograde axonal degeneration with ibotenic acid and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) retrograde tracing study revealed that some degenerating thalamocortical axon terminals from the mediodorsal thalamic nucleus (MD) directly formed asymmetrical synaptic contacts predominantly with dendritic spines of apical dendrites of WGA-HRP-labeled corticothalamic projection neurons to MD in the prelimbic cortex of the rat. This result suggests that there is a monosynaptic feedback loop from and to MD via deeper layer neurons in the prelimbic cortex.

Animals↗
PubMed1993

A comparative study of the solution structures of tachyplesin I and a novel anti-HIV synthetic peptide, T22 ([Tyr5,12, Lys7]-polyphemusin II), determined by nuclear magnetic resonance.

The solution structure of tachyplesin I, which was isolated from membrane acid extracts of the hemocytes from the Japanese horseshoe crab (Tachypleus tridentatus), was determined by nuclear magnetic resonance (NMR) and distance geometry calculation. Tachyplesin I takes an antiparallel beta-sheet structure with a type-II beta-turn. Recently, among more than 20 synthetic peptides associated with tachyplesin and its isopeptide (polyphemusin), we found that a novel compound, which we designated as T22 ([Tyr5,12, Lys7]-polyphemusin II), strongly inhibited the human immunodeficiency virus (HIV)-1-induced cytopathic effect and viral antigen expression. The solution structure of T22 was investigated using NMR, and its secondary structure was confirmed to be similar to that of tachyplesin I. The anti-parallel beta-sheet structure and the several amino-acid side chains on the plane of the beta-sheet of T22 are thought to be associated with the expression of anti-HIV activity.

Amino Acid Sequence↗
PubMed1993

[CT evaluation of the pelvic cavity after total cystectomy].

CT scans were performed 40 times in 28 postcystectomy patients to identify the type and location of tumor recurrence. Sixteen patients showed tumor recurrence. Patients without recurrence showed a complete symmetric pelvis and a thin string that looked like an operation scar. Cutaneous ureterostomy showed small tube-like structures, and ileal conduit looked like herniation of the ileum. Cases with recurrent tumors were divided into 3 patterns, 1) pelvic abscess recurrence, 2) anterior abdominal wall thickening, 3) pelvic lateral wall thickening, and combinations of these types. The abscess-recurrence type often showed air within the mass or a fuzzy contour that could not be differentiated from true inflammatory abscess. Anterior abdominal wall thickening was usually accompanied with abscess-type recurrence and appeared as thickening of the operation scar. Lateral wall thickening was usually seen at the site of the obturator internus muscle or obturator node. Patients without recurrence had no complaints except for two who had ileus. All patients with recurrence except one had complaints of pain, abnormal secretion, or a palpable mass. Because all patients with recurrence already had a relatively large tumor at the time of CT, routine follow-up CT is recommended even if the patient has no complaints.

Carcinoma, Transitional Cell↗
PubMed1993

Effect of ethanol on the development and maturation of synapses in the rat hippocampus: a quantitative electron-microscopic study.

The effects of chronic ethanol administration on the development and maturation of synapses in the strata radiatum and lacunosum-moleculare of CA1 in the hippocampus were quantitatively examined in rats exposed to ethanol for the entire period of fetal life as well as the whole period of postnatal life. Synapse densities in the strata radiatum and lacunosum-moleculare of the ethanol-treated group were significantly lower than those of the control group at 2, 14, 21, and 70 days of age. However, the rates of density reduction did not change between either of the strata that receive different groups of afferent fibers. The ratio of axospinous to axoshaftic synapses also did not change between control and ethanol-treated groups. These data suggest that chronic administration of ethanol reduces the density of synapses in this area and that this effect is not specific to neither the type of afferent fibers nor the type of synapses.

Animals↗
PubMed1993

Urinary alpha 1-microglobulin as an index of proximal tubular function in early infancy.

Urinary alpha 1-microglobulin (U-A1M) was measured in healthy term infants on days 1, 4, 7, 14, 28, 90 and 180 of life. U-A1M was high until day 14 and declined thereafter. It was significantly correlated with urinary beta 2-microglobulin (U-B2M) throughout the study, but not with serum A1M on days 1 or 7. Similar to U-B2M, U-A1M in the clinically stable term infants with intrauterine growth retardation (n = 4-7) was not elevated on days 1-7. In the sick infants who needed immediate resuscitation at birth (n = 4-8), U-A1M was well as U-B2M was high on days 1-7 and then decreased to normal levels, suggesting that U-A1M can be used as a sensitive marker of acute proximal tubular damage and its recovery. These observations indicate that U-A1M is a useful index of proximal tubular function in early infancy.

Alpha-Globulins↗
PubMed1993

Calcium pump expression in human bone and soft tissue tumours.

Ninety-one cases of human bone and soft tissue tumours were studied for calcium pump expression by strepto-avidin-biotin immunohistochemical staining with a monoclonal antibody against sarcoplasmic reticulum calcium-ATPase (mAb6F5). Two out of 5 cases of embryonal rhabdomyosarcoma, 1 out of 5 cases of biphasic synovial sarcoma, 4 of 4 cases of chordoma and all of 3 chondrosarcoma cases were positive for mAb6F5. Although this novel monoclonal antibody can be used as a marker of myogenic tumours, the present positive result for endoplasmic reticulum calcium-ATPase (calcium pump) in other tumours including chordoma, chondrosarcoma and synovial sarcoma indicates a wider immunoreactivity. The findings further suggest that intracellular calcium may play an important role in cell proliferation and/or differentiation.

Adult↗
PubMed1993

Bladder tumors: staging with gadolinium-enhanced oblique MR imaging.

To clarify the importance of imaging plane in evaluation of invasion by tumor into muscle, 50 patients with bladder tumors underwent examination with magnetic resonance (MR) imaging performed with an oblique plane and the early phase of contrast enhancement. After the ideal oblique plane was selected, an oblique T2-weighted image was obtained. Gadopentetate dimeglumine was then administered, and an oblique T1-weighted image was obtained. The staging based on oblique T2-weighted and oblique contrast material-enhanced T1-weighted MR images was then correlated with histopathologic staging. The respective accuracies of oblique contrast-enhanced T1-weighted and oblique T2-weighted images were 78% and 60% for overall staging (P < .05), 90% and 74% for differentiation between (a) stage T1 and lower-stage tumors and (b) stage T2 and higher-stage tumors (P < .05), and 92% and 88% for differentiation between (a) stage T2 and lower-stage tumors and (b) stage T3a and higher-stage tumors (P > .05). Oblique MR imaging performed in conjunction with the early phase of contrast enhancement showed significantly high staging accuracy, especially in differentiation between superficial tumors and tumors with superficial muscle invasion.

Adult↗
PubMed1993

Bladder wall morphology: in vitro MR imaging-histopathologic correlation.

To study the morphology of the normal and inflamed bladder wall, the findings of magnetic resonance imaging and histopathologic examination of 13 in vitro specimens were correlated. Normal bladder wall appeared as a band of intermediate signal intensity on T1-weighted images and as bands of low (inner) and intermediate (outer) signal intensity on T2-weighted images. Inflamed bladder walls demonstrated two additional inner bands of intermediate (inner) and high (innermost) signal intensity on T1-weighted images and high (inner) and low (innermost) signal intensity on T2-weighted images. The mean histopathologic percentages of muscle bundles in inner and outer bands that appeared on T2-weighted images were 92.5% +/- 4.9 and 78.3% +/- 8.2, respectively. The authors conclude that the total thickness of the two bands of differing intensity that appeared on the T2-weighted images of the normal bladder wall correlated well morphometrically with the muscle layers in the histopathologic specimens, and that the different signal intensities in the muscle layer represent a compact inner and looser outer arrangement of smooth muscle bundles.

Aged↗
PubMed1993

Study on impaired metabolism of guanidinoacetic acid in chronic renal failure rabbits with special reference to impaired conversion of arginine to guanidinoacetic acid.

Most chronic renal failure (CRF) patients show low serum concentrations of guanidinoacetic acid (GAA). In this study, the author investigated the impaired metabolism of GAA in CRF focusing on the transformation of arginine (Arg) to GAA by analyzing CRF rabbits using 14C-Arg. The CRF group which consisted of 6 CRF rabbits, was compared with 6 normal rabbits (normal group). Blood samples were obtained from each abdominal aorta after a bolus injection of 30 mu Ci of 14C-Arg into an ear vein of each rabbit. After the last sampling, the left kidney was obtained for measurement of renal glycine amidinotransferase (GAT) activity. In each blood sample, the concentrations of blood urea nitrogen (BUN), serum creatinine (Cr), GAA and Arg were measured. The radioactivity of serum 14C-GAA was measured with a liquid scintillation system. delta 14C-GAA was calculated as the difference between the 14C-GAA count and the 14C-background count. Serum concentrations of GAA and renal GAT activity were significantly lower in the CRF group as compared with the normal group. Significant negative correlations were found between the two groups for the following comparisons: serum concentrations of Cr and GAA, concentrations of BUN and renal GAT activity, and serum concentrations of Cr and renal GAT activity. There was a significant positive correlation in the two groups, between renal GAT activity and serum concentrations of GAA. The fact that the concentrations of neither GAA nor Arg changed significantly after the injection of 14C-Arg in either group suggested that the dosage of injected Arg is not sufficient to affect the transformation of Arg to GAA.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Synthetic study on selenocystine-containing peptides.

N-9-Fluorenylmethoxycarbonyl-Se-4-methoxybenzylselenocysteine++ + [Fmoc-Sec(MBzl)-OH] was synthesized from selenocystine and successfully applied to Fmoc-based solid-phase peptide synthesis. The stability and the deprotection conditions of the Se-MBzl group were examined. The diselenide bond of a peptide was directly and effectively established between Sec(MBzl) residues by treatment with iodine or the dimethyl sulfoxide-trifluoroacetic acid system. Reduction kinetics of diselenide and disulfide in model peptides by reduced glutathione were also studied comparatively.

Amino Acid Sequence↗
PubMed1993

Hyperthermotherapy for postoperative local recurrences of rectal cancer.

Between November 1984 and August 1992 we used hyperthermotherapy in six cases of local recurrence of rectal cancer. Hyperthermotherapy was performed on the average 8.7 times (range: 3-18) for each patient for 60 min each. All patients underwent combined radiotherapy and received a mean radiation dose of 42.5 Gy (range: 9-60 Gy). Five patients underwent heating within 1 h after irradiation and one patient simultaneously with the irradiation. Four patients underwent combined chemotherapy and two patients immunotherapy. Before the treatment all patients had painful lesions, but pain decreased posttherapeutically in five patients. Performance status improved in two patients. High carcinoembryonic antigen levels prior to the therapy in four patients decreased in all cases after treatment. Posttherapeutical computed tomograms revealed only minor response or no changes. After the treatment, four patients died of exacerbations of recurrent tumors and one patient of distant metastases. The patient who underwent simultaneous radiohyperthermotherapy is presently alive, in August 1992, 38 months after initiation of the treatment. The 50% survival time after initiation of the treatment was 25 months (range: 10-38 months). Hyperthermotherapy combined with radiotherapy, chemotherapy and/or immunotherapy was useful for the alleviation of pain in patients who developed local recurrence after surgery, and improved survival after recurrences can be expected.

Adult↗
PubMed1993

Hyperthermotherapy added to the multidisciplinary therapy for penile cancer.

We performed a long-term follow-up of 4 patients with penile cancer who underwent hyperthermotherapy from August 1985 until August 1992. Hyperthermia was applied using a frequency of 350 MHz with a waveguide applicator twice a week for 60 min each for an average of 9.5 times (varying from 6 to 13 times). The total heating time that the temperature of urethra could be kept above 42 degrees C, was 166 min on the average (ranging from 0 to 463 min). Two patients classified as stage I according to the Jackson classification and 1 patient classified as stage IV underwent combined radiotherapy and received an average radiation dose of 53 Gy (range, 40-70 Gy). Among these patients 2 underwent combined chemotherapy with bleomycin or peplomycin. Malignant cells disappeared posttherapeutically and in August 1992, after an average of 5 years and 9 months (varying from 4 years 6 months to 6 years 10 months), the patients were free of recurrences. The one patient on stage IV had extensive invasion of the abdominal wall, but still recovered completely. One patient on stage III underwent combined chemotherapy and hyperthermotherapy, but heating had obviously been insufficient. There was a residue of malignant cells after the treatment and we performed a penectomy. Regarding functional preservation of the penis a multidisciplinary therapy incorporating hyperthermotherapy can be expected to increase the curativity. This indicates that it could induce in an advanced case, where an operation would be difficult, complete remission.

Adult↗
PubMed1993

Diagnosis of urinary tract infection by urine microscopy using a disposable counting chamber.

Routine urinalysis is performed as a screening test for urinary tract infection (UTI), but is not very reliable. We assessed the usefulness of microscopic examination of unspun urine using a disposable slide with counting chambers for the diagnosis of UTI caused by a variety of species of bacilli. One hundred and seventy-two urine samples were obtained from 113 subjects (60 male and 53 female), including 84 inpatients, aged 20-96 years. The urine samples were examined for bacteriuria and pyuria using a counting chamber, and the reliability of this method in predicting significant bacteriuria defined by routine urine culture and Gram stain of urine smears was analyzed. Significant bacteriuria was diagnosed in 68 urine samples, including 34 from indwelling catheters, from 52 patients mostly having underlying diseases. Only 12 of the positive urine samples contained E. coli, with a variety of other bacilli including cocci found in the rest. The counting chamber method detected bacteriuria in 64 of these 68 positive samples (sensitivity = 94%). Specificity was 88%. While the sensitivity and specificity of pyuria (WBC > 10 microliters-1) were 79 and 71%, respectively, both sensitivity and negative predictive value were as high as 97% when bacteriuria or pyuria was present. We demonstrated that urine microscopy on a disposable counting chamber is a simple, sensitive and time- and cost-saving method for the diagnosis of UTI caused by a variety of bacterial species including cocci.

Adult↗
PubMed1993

[Neoadjuvant therapy for prostatic cancer].

Neoadjuvant therapy for prostatic cancer might be important to increase cure rates of the disease and preservability of the organs. There were 43 cases in a period of 1975-1990 in which total prostatectomy were performed after neoadjuvant therapy. According to the clinical stage, there were 14 cases in B, 23 in C, 4 in D1 and 2 in D2. The median duration of neoadjuvant therapy was 4 months. Clinical response of the prostate in 37 evaluable cases was as follows; 6 cases were PR (16%), 12 cases were MR (32%) and 19 cases were NC (52%). Histopathological effect was as follows; 5 cases were grade 0a (12%), 12 cases were grade 0b (28%), 16 cases were grade 1 (37%), 8 cases were grade 2 (19%) and 2 cases were grade 3 (5%). In 2 cases with histopathological effect of grade 3, lymph node metastases were thought to have obviously disappeared. Histopathological effect seemed related to clinical response. In cases given neoadjuvant therapy for less than 2 months, no adequate clinicopathological effect was obtained. Cases that could achieve downstaging were 8; 1 in grade 0a, 2 in grade 1, 3 in grade 2 and 2 in grade 3. These results suggest that neoadjuvant therapy plays an important role in advanced prostatic cancer.

Aged↗
PubMed1993

[Successful interferon therapy of renal cell carcinoma with tumor thrombus extending into the inferior vena cava--a case report].

It is a fact that there are few effective drugs available except for interferon for that treatment of renal cell carcinoma, and the efficacy rate of interferon is less than 10% even if multiple drug regimens are included. We have experienced a case of renal cell carcinoma in whom interferon therapy was successful in reducing the primary lesion and tumor thrombus extending into the inferior vena cava. A 57-year-old man was admitted to our department with a complaint of macroscopic hematuria. Computed tomography and magnetic resonance imaging revealed a right renal tumor and the tumor thrombus. Because of the past history of his myocardial infarction, a radical operation was considered risky. So we started interferon therapy. Four months after the start of interferon therapy, the primary lesion and the tumor thrombus markedly reduced in their size, and the clinical response was evaluated as partial response by response criteria for urological cancer treatment. Therefore, radical nephrectomy and tumor thrombectomy were performed with extracorporeal circulation. Histopathologically, necrosis and lymphocyte infiltration into the cancer cell focus were seen, and these immunologic reactions were considered at the affection of interferon. In some case, interferon therapy is a useful and safe in the treatment of the primary lesion of renal cell carcinoma, and further investigation must be studied.

Carcinoma, Renal Cell↗