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Biomedical subjects

K Oohara

Publications and source records attributed to K Oohara.

At least 37 records · Page 2Linked to original sources
PubMed1990

Comparative effects of antidepressants, amitriptyline, and maprotiline on intraventricular conduction, effective refractory period, and incidence of ventricular arrhythmias induced by programmed stimulation in dog hearts after myocardial infarction.

The effects of amitriptyline and maprotiline, standard tricyclic and tetracyclic antidepressants, on intraventricular conduction, the effective refractory period (ERP), and the incidence of ventricular arrhythmias induced by programmed stimulation were studied and compared in dog hearts after myocardial infarction. Amitriptyline at doses of 1-3 mg/kg significantly slowed ventricular conduction of the infarcted zones in a frequency-dependent and dose-dependent manner. Amitriptyline at doses of 2 and 3 mg/kg slowed conduction slightly in normal zones. The ERP was prolonged by amitriptyline at a dose of 2 mg/kg. Amitriptyline increased the incidence of ventricular arrhythmias induced by programmed stimulation. Maprotiline at doses of 1-3 mg/kg slowed conduction in infarcted zones to a lesser extent as compared with amitriptyline, although severely depressed conduction in the infarcted zone was obviously slowed by maprotiline. Maprotiline did not increase the incidence of ventricular arrhythmias significantly. From the present results, maprotiline appears to have less cardiac toxicity than amitriptyline, although maprotiline produces a slight decrease in conduction of infarcted zones.

Action Potentials↗
PubMed1989

Giant congenital nevus and malignant melanoma.

Frequency of malignant transformation arising in giant congenital nevi is considered to be 4%-5%. More than a half of the patients in which malignant melanoma developed in giant congenital nevi were under the age of 10. It may be hypothesized that dermabrasion of giant congenital nevus may provoke malignant transformation. Some of the cell groups in giant congenital nevus are potentially malignant. Some groups of nevus cells were larger in size than those of other portions of nevus. Electron microscopic observation revealed that nuclei of these larger nevus cells were significantly indented, and melanization of melanosomes was irregular. Coexistence of alpha-like actin with beta- and gamma-actins in giant congenital nevus cells and disappearance of alpha-like actin in malignant melanoma cells were noted.

Actins↗
PubMed1987

Transitional cell carcinoma of the urinary tract associated with vulvar Paget's disease: a report of two cases.

Two cases of the urothelial cancers associated with extramammary Paget's disease are reported. In one patient, vulvar Paget's disease was discovered 6 years after complete resection of a ureteral tumor. In another patient, vulvar and vaginal Paget's disease developed during a period of repeated transurethral surgery leading up to the final total cystectomy for recurrent bladder carcinoma. Since genital Paget's disease is frequently accompanied by internal malignancies, a skin biopsy is mandatory when an eczematous lesion has been persistent in the genital region of patients with genitourinary cancers.

Carcinoma, Transitional Cell↗
PubMed1986

Pretibial epidermolysis bullosa. Successful therapy with a skin graft.

A patient with pretibial epidermolysis bullosa was successfully treated with a skin graft. Ultrastructural examination revealed a decreased number of and rudimentary anchoring fibrils (AFs) in the pretibial area in contrast to normal AFs in the grafted skin obtained from a nonpredilection site. Our results indicate the importance of AFs in the pathogenesis of pretibial epidermolysis bullosa.

Adolescent↗
PubMed1986

Epidermolysis bullosa acquisita: clinical response to plasma exchange therapy and circulating anti-basement membrane zone antibody titer.

Epidermolysis bullosa acquisita has been recognized as a rare autoimmune mechanobullous disorder since the detection of immunoglobulin and complement deposits along the basement membrane zone. A circulating anti-basement membrane zone antibody has also been detected in some cases. We are reporting a case of epidermolysis bullosa acquisita in which clinical symptoms were well correlated with the circulating anti-basement membrane zone antibody titers. Although the patient initially responded very well to corticosteroid therapy, remission could not be maintained without increasing the dosage. Other therapies, including azathioprine, dapsone, vitamin E, and gold sodium thiomalate, produced no beneficial effects. Although a high dose of oral corticosteroid and cyclophosphamide decreased the antibody titer and blister formation, this therapy had to be terminated because of side effects. Plasma exchange therapy in combination with corticosteroid and low-dose cyclophosphamide resulted in a marked decrease of the anti-basement membrane zone antibody titer and clinical improvement. Thus plasma exchange therapy may be a useful adjunct to conventional treatments for patients with epidermolysis bullosa acquisita.

Autoantibodies↗
PubMed1986

Evaluation of the mutagenicity of 1,N6-ethenoadenine- and 3,N4-ethenocytosine-nucleosides in Salmonella typhimurium.

To provide supporting evidence for the hypothetical involvement of etheno-derivative formation in DNA in chloroacetaldehyde-mediated mutagenesis, etheno nucleosides were examined for their direct-acting mutagenicity in Salmonella typhimurium strain TA100. The results, however, have shown that 1,N6-ethenoadenosine, 1,N6-ethenodeoxyadenosine, 3,N4-ethenocytidine and 3,N4-ethenodeoxycytidine lack mutagenicity in this test system. A lesson learned in this study is that 3,N4-ethenocytosine nucleosides prepared synthetically or obtained from commercial sources can give false positive mutagenicity due to mutagenic contaminants.

Adenine↗
PubMed1985

[Clinical experience with aspoxicillin in the pediatric field].

Aspoxicillin (TA-058, ASPC) was given intravenously to 20 children with the following acute bacterial infections; 11 cases of bronchopneumonia, 5 cases of urinary tract infection, 2 cases of acute bronchitis, 1 case of staphylococcal scalded skin syndrome and 1 case of subcutaneous abscess. Clinical effectiveness was obtained in 14 cases out of 20 cases (70%) and bacteriological eradication in 8 cases out of 10 cases (80%). With ASPC the following side effects developed; transient diarrhea in 1 case, eruption in 1 case and slight elevation of GOT in 1 case. From the above clinical results, it is apparent that ASPC is an useful antibiotic for treating pediatric patients with various kinds of bacterial infections.

Amoxicillin↗
PubMed1985

[Clinical experience with aztreonam in the pediatric field].

Aztreonam (AZT) was given intravenously to 20 children with the following acute bacterial infections: 13 cases of bronchopneumonia, 5 cases of urinary tract infection, 1 case of cervical lymphadenitis with acute tonsillitis and 1 case of acute enteritis. Clinical effectiveness was obtained in 17 cases of 20 cases and bacteriological effectiveness in 10 strains out of 11 strains. No side effect was observed except for 2 cases with eruption, 1 case with slight elevation of GPT, 1 case with slight elevation of GOT and 1 case with slight elevation of GOT and GPT. From the above clinical results, it is apparent that AZT is a useful antibiotic for treating pediatric patients with various kinds of bacterial infections.

Acute Disease↗
PubMed1984

Acquired, bilateral nevus of Ota-like macules.

Blue-brown macules of the face occurring on both sides of the forehead, temple, eyelids, malar area, alae of the nose, and root of the nose are often observed in middle-aged Japanese women. These lesions histologically are a form of dermal melanocytosis as shown by electron microscopic examination. They differ clinically from nevus of Ota. The differential diagnosis includes nevus of Ota, Riehl's melanosis (female facial melanosis), and melasma. The differences between them are discussed.

Adult↗
PubMed1983

N4-aminocytidine, a nucleoside analog that has an exceptionally high mutagenic activity.

The reaction of cytidine with hydrazine to give N4-aminocytidine was greatly promoted by addition of a less-than-stoichiometric amount of bisulfite, and the product was isolated in a good yield. N4-Aminocytidine was strongly mutagenic to bacteria (Salmonella typhimurium TA100 and TA1535, and E. coli WP2 uvrA) and to phage (phi X174 am3). The activity did not require the presence of mammalian microsomal fraction in the system. The mutagenic potency of N4-aminocytidine in these systems was two orders of magnitude greater than that of N4-amino-2'-deoxycytidine, and more than two orders of magnitude greater than that of N4-hydroxycytidine. The greater activity of the riboside than the deoxyriboside was ascribed to the lack of deoxycytidine kinase in these cells. This compound may be useful as a powerful mutagen to induce a transition mutation in microorganisms.

Bacteriophage phi X 174↗
PubMed1983

Development of a malignant proliferating trichilemmal cyst in a patient with multiple trichilemmal cysts.

A case of multiple trichilemmal cysts is presented. After trauma, a large tumor developed on one of the cysts. The histologic features of this tumor were similar to those of proliferating trichilemmal cyst, but some of the tumor cells showed definite nuclear atypicality. The malignant potential of this tumor was confirmed by later development of metastases to the regional lymph nodes.

Cysts↗