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Biomedical subjects

M Hamada

Publications and source records attributed to M Hamada.

At least 253 records · Page 14Linked to original sources

Diagnostic sensitivity of motor nerve conduction studies in ulnar neuropathy at the elbow.

Seventy-six patients with ulnar neuropathy at the elbow were divided into 3 classes (Grades I, II, and III) according to their clinical features and the maximal motor nerve conduction velocity (MCV), and the amplitude ratios at the across-elbow segment were retrospectively analyzed. To determine the criteria for abnormality, a control study was conducted on 150 healthy volunteers ranging in age from 20 to 89 years (6 age groups). The normal value for MCV could be set for two age groups: those under 60 and those over 60 years old. The 95% confidence limit was 54m/s for the former and 50m/s for the latter. There was no statistically significant difference in the amplitude ratio among the age groups. The confidence limit was set uniformly at 0.82 (above elbow/below elbow). An abnormality in either MCV or the amplitude ratio was found in 66.7% of Grade I (recent and mild symptoms), 89.7% of Grade II (persistent symptoms), and 100% of Grade III cases (marked intrinsic muscle atrophy). Evaluation using the combination of MCV and the amplitude ratio, considering the age-related normal value, appeared to be useful in establishing a differential diagnosis of ulnar neuropathy at the elbow.

Adult↗

Warfarin-induced eosinophilic pleurisy.

A 51-year-old man was admitted to our hospital because of dry cough and low grade fever with right-sided pleural fluid and blood eosinophilia. Warfarin had been prescribed following coronary artery bypass grafting. After the discontinuation of warfarin the clinical and chest X-ray findings improved; readministration of the drug caused recurrent blood eosinophilia and pleural effusion in the other lung. Since no other specific etiologies for eosinophilia and pleural effusion were determined by extensive evaluation, warfarin seemed to be associated with his illness. This is the first report of warfarin-induced eosinophilic pleurisy.

Anticoagulants↗

Belactins A and B, new serine carboxypeptidase inhibitors produced by Actinomycete. I. Taxonomy, production, isolation and biological activities.

Belactins A and B, new inhibitors of serine carboxypeptidase were discovered in the fermentation broth of Saccharopolyspora sp. MK19-42F6. They were purified by ethyl acetate extraction, silica gel chromatography, Sephadex LH20 chromatography, Capcellpak C18 SG120 reversed phase HPLC and centrifugal partition chromatography (CPC) following their inhibitory activity against carboxypeptidase Y (CP-Y). The inhibition constants (Ki) of belactins A and B against CP-Y are 0.14 and 0.27 microM respectively. Belactins A and B have highly specific inhibitory activities for CP-Y among various peptidases, have no antimicrobial activities at 100 micrograms/ml and have low toxicities.

Benzamides↗

[An 80-year-old female with pneumopericardium due to gastric perforation].

An 80-year-old woman was admitted to our hospital because of chest oppression and general malaise. On admission, auscultation of the heart revealed friction rub, so-called water-wheel like murmur. Chest X-ray film and computed tomography showed cardiomegaly and free air in the pericardium. Electrocardiogram showed low voltage with ST elevation in II, III, aVF and V1-V4. These findings suggested that the patient had pneumopericardium with pericarditis. Wenchebach type A-V block and atrial bradycardia appeared. Thus, the ventricular pacing was performed. However, patient died of multiple organ failure. The postmortempericardiography showed the gastro-pericardial fistula with hiatus hernia.

Aged↗

[Influence of aging upon changes in symptoms and cardiac size associated with surgical repair of atrial septal defect in adults].

To elucidate the influence of aging upon the improvement of symptoms and cardiac size associated with surgical repair of atrial septal defect, clinical symptoms, cardiothoracic ratio and hemodynamic variables in older patients (group A; age at operation > or = 50 years old, n = 11) were compared with those in younger patients (group B; age at operation < 50 years old, n = 8). There were no differences in hemodynamic variables, i.e., peak systolic pulmonary pressure, pulmonary to systolic flow ratio (Qp/Qs), pulmonary to systolic vascular resistance ratio (Rp/Rs) and left to right shunt ratio between the two groups. Symptomatic benefits occurred in all patients, although 3 patients in group A who had atrial fibrillation preoperatively still displayed symptoms such as exertional dyspnea. The postoperative (after 3 months) cardiothoracic ratio improved in all patients except for 3 patients in group A who were operated at over 60 years of age. Although there was no significant difference in preoperative cardiothoracic ratio between the two groups, the postoperative cardiothoracic ratio in group B was significantly smaller than that in group A. These results indicate that operative closure of atrial septal defect is recommended for all patients aged 50 years old or older, but early improvement of symptoms and cardiomegaly in older patients is lower than that in younger patients.

Adult↗

Tetrodecamycin and dihydrotetrodecamycin, new antimicrobial antibiotics against Pasteurella piscicida produced by Streptomyces nashvillensis MJ885-mF8. I. Taxonomy, fermentation, isolation, characterization and biological activities.

The novel antimicrobial antibiotic against Pasteurella piscicida, tetrodecamycin (1) and weakly active dihydrotetrodecamycin (2) were isolated from the fermentation broth of Streptomyces nashvillensis MJ885-mF8. They were purified by adsorption on Diaion HP-20, silica gel column chromatography and crystallization. The MICs of 1 were 6.25 approximately 12.5 micrograms/liter and 1.56 approximately 6.25 micrograms/ml against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and 12 strains of P. piscicida, respectively.

Animals↗

Derivatives of tetrodecamycin.

The derivatives of tetrodecamycin (1), being introduced acyl, carbamoyl and alkyl groups at 14-hydroxyl group and modified at exo-methylene group, were synthesized and evaluated on their antibacterial activities. Although 14-O-substituted tetrodecamycins (3 approximately 19) showed weak activity against Pasteurella piscicida, they were more active against Gram-positive bacteria than 1. Among them, 15 showed approximately 10-fold higher activity than 1. The derivatives (20 approximately 23) modified at 4 or 5 positions had moderate antibacterial activity. The absolute structure of 4(R),5-dibromotetrodecamycin (23) was determined by X-ray crystallographic analysis.

Anti-Bacterial Agents↗

Azicemicins A and B, a new antimicrobial agent produced by Amycolatopsis. I. Taxonomy, fermentation, isolation, characterization and biological activities.

A new structural class of the antibiotic, azicemicins A (1) and B (2) were isolated from the culture broth of the strain MJ126-NF4, which was closely related to Amycolatopsis sulphurea. They were purified by adsorption on Diaion HP-20, silica gel column chromatography and preparative TLC. The molecular formulas of 1 and 2 were determined to be C23H25O9N and C22H23O9N by HRFAB-MS, respectively. Azicemicins A and B have moderate growth inhibiting activity against Gram-positive bacteria and mycobacteria.

Actinobacteria↗

Thiazinotrienomycins, new ansamycin group antibiotics.

New triene-ansamycins designated thiazinotrienomycins A, B, C, D and E were isolated from culture broth of Streptomyces sp. MJ672-m3 for their activities against cervical cancer cell lines. The structures and some biological and biochemical properties of the antibiotics were determined.

Animals↗

Isolation from Streptomyces of a novel naphthoquinone compound, naphthablin, that inhibits Abl oncogene functions.

In the course of our screening for inhibitors of abl oncogene function, a culture filtrate of Streptomyces aculeolatus, induced normal flat morphology in v-abl-expressing NIH3T3 cells. The active substance was isolated through ethyl acetate extraction, silica gel column chromatography, and reverse-phase HPLC. Mass and NMR spectroscopy including HMBC revealed that it had a novel naphthoquinone structure with a monoterpene, and we named it "naphthablin". Naphthablin inhibited Abl-induced morphological transformation in v-ablts-NIH3T3 cells at around 30 micrograms/ml, and specifically inhibited RNA synthesis.

Cells, Cultured↗

A clinical study of lectin-reactive alpha-fetoprotein as an early indicator of hepatocellular carcinoma in the follow-up of cirrhotic patients.

Levels of two types of lectin-reactive alpha-fetoprotein (AFP), designated AFP-L3 and AFP-P4+P5, were analyzed with Lens culinaris agglutinin A and AFP-P4+P5 with erythroagglutinating phytohemagglutinin, respectively, in an attempt to determine the utility and significance of these macromolecules as early indicators of hepatocellular carcinoma during the periodic follow-up of cirrhotic patients. The subjects were 51 of 190 consecutive cirrhotic patients in whom hepatocellular carcinoma developed during a 6-year follow-up period and 21 cirrhotic patients without hepatocellular carcinoma. Serum AFP levels were of limited value to diagnose and predict hepatocellular carcinoma. The relative levels of AFP-L3 and AFP-P4+P5 in patients with hepatocellular carcinoma at the time of tumor detection were significantly higher than those in patients with cirrhosis. The sensitivity was 61%, and the specificity was 90%. Fourteen patients (48%) of 29 patients with small hepatocellular carcinomas less than 2 cm in diameter showed elevated percentage of lectin-reactive AFP. Retrospective examination of 21 patients who were positive for lectin-reactive AFP at diagnosis of hepatocellular carcinoma showed that 41% of them had already expressed lectin-reactive AFP 12 months before the direct detection of hepatocellular carcinoma by diagnostic imaging. These results lead us to conclude that the level of lectin-reactive AFP is a suitable predictive marker for the early recognition of hepatocellular carcinoma in the follow-up of patients with cirrhosis, and that measurements of the level of lectin-reactive AFP should be added to the screening methods that are now in use.

Biomarkers, Tumor↗