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Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

At least 163 records · Page 9Linked to original sources
PubMed1991

Evaluation of the invasive potential of superficial bladder cancer by adenosine triphosphate measurement.

In order to predict the malignant potential of superficial bladder cancer, in 121 patients with this malignancy adenine nucleotide levels (adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate) and energy charge in bladder cancer cells were determined. The nucleotides were analyzed according to the method of Bücher, and the energy charge was calculated by applying the formula of Atkinson. It was clearly pointed out that superficial bladder tumors, which became invasive and/or metastatic, had higher levels of adenylate compounds than those which became not. Our results show that a high correlation exists between adenine nucleotide content and tumor progression.

Adenosine Diphosphate↗
PubMed1991

Synthesis of metabolites of S-1452, an orally active thromboxane A2 receptor antagonist.

The synthesis of 16 metabolites of S-1452, an orally active thromboxane A2 (TXA2) receptor antagonist, is described. Regioselective hydroxylation at C-5 or C-6 of the bicyclo[2.2.1]heptane skeleton of the optically active intermediate 16 was attempted by using 9-borabicyclo[3.3.1]nonane followed by H2O2 or m-chloroperbenzoic acid (m-CPBA) and then LiA1H4, to obtain the hydroxylated product 17a or 17b, respectively. Modification of the C-2 substituent of 17a and 17b afforded eight metabolites of S-1452. Eight non-hydroxylated metabolites were synthesized by using a similar reaction sequence.

Animals↗
PubMed1991

Isolation of and calcium kinetics in cochlear inner hair cells of the guinea pig.

Single inner hair cells of the guinea pig cochlea were isolated using enzymatic and mechanical techniques. The intracellular free calcium ion concentrations [( Ca2+]i) of the isolated inner hair cells were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. In the presence of 1 micron ionomycin, a Ca2+ ionophore, there was an irreversible increase in [Ca2+]i. The 150 mM KCl stimulation, which induces a depolarization, resulted in a temporary increase in [Ca2+]i. This increase in [Ca2+]i was not observed under conditions of depolarization, in Ca(2+)-free medium. These observations are interpreted to mean that the [Ca2+]i during membrane depolarization mainly originates from an influx of extracellular Ca2+ into the cytoplasm.

Animals↗
PubMed1991

[A model of orthotopic transplantation in mice using MBT-2].

We attempted to produce a malignant urinary bladder carcinoma in mice by transplanting MBT-2 cells. MBT-2 carcinoma about 3.0 x 10(3) cells/0.02 ml were successfully transplanted into the bladder wall with an incidence of 80% (20/25) after three experimental weeks. Inoculated tumor cells grew expansively into the bladder cavity from the bladder submucosa, and invaded the muscle layer. We observed that tumors caused gross hematuria and bilateral hydronephrosis. This malignant tumor model in which a tumor is implanted into its original organs seems to be useful for predicting clinical effectiveness in experimental cancer therapy.

Animals↗
PubMed1991

[Intra-arterial cisplatin and concurrent radiation for invasive bladder cancer].

Fifteen patients with invasive bladder cancer were treated with selective intra-arterial cisplatin and external beam radiotherapy (30.6 Gy over 3 weeks) prior to a planned cystectomy. Cisplatin, in total 200 mg, was administered via bilateral internal iliac artery infusion during the course of radiotherapy. Seven patients were evaluated for local response. Partial response (PR) was revealed in 4, and minor response (MR) in 3. Ten patients received total cystectomy, and pathological effects by the criteria adipted by Japanese Urological Association and The Japanese Society of Pathology, were as follows: Ef. 3 in 1 case, Ef. 2 in 6. Ef. 1b in 1 and Ef. 1a in 2. Down staging was observed in 8 patients from the clinical to the pathological stage. Thirteen patients are alive for 21 months. Two patients have died (1 lung infarction, 1 pancreatic cancer). Though nausea and sciatica-like pain were observed in some cases, there was no severe systemic side effects such as bone marrow suppression and renal toxicity. From these results it is concluded that this therapeutic modality could be effective in the preoperative work-up of candidates for total cystectomy, and also that it could be useful in the treatment of patients in whom total cystectomy is contraindicated.

Aged↗
PubMed1991

[Inhibition by proton irradiation on the development of invasive bladder carcinomas induced by N-butyl-N-(4-hydroxybutyl) nitrosamine in mice].

Fifty-five female C3H/He mice were given 0.05% N-bytyl-N-(4-hydroxybutyl) nitrosamine in their drinking water for 18 weeks. In week 19, eleven mice (group 3) were sacrificed to confirm that they all had bladder carcinoma. The remaining mice were divided into two groups. Group 1 received 20 Gy of proton irradiation over the whole pelvis, while group 2 received no treatment as a control. After 3 weeks all the animals were sacrificed and their bladders were resected to weigh and to examine histologically. The average weight of the bladder, as an index of the tumor volume, was 67.7 mg in group 1, 120.6 mg in group 2 and 106.5 mg in group 3. There was a significant differences (p less than 0.05) between group 1 and group 2. The incidences of superficial (pT1) and deeply invasive (pT2-3) bladder carcinomas were [10/18 (56%) and 8/18 (39%)] in group 1, [3/17 (18%) and 14/17 (82%)] in group 2 and [2/11 (18%) and 9/11 (82%)] in group 3, respectively. These rates of incidence were significantly different (p less than 0.05) between group 1 and group 2. However, there was no significant difference (p = 0.068) between group 1 and group 3. These results indicate that proton irradiation is effective for treatment of invasive bladder carcinoma in mice.

Animals↗
PubMed1991

[A cohort study on deaths from SMON in Japan].

Causes and risk factors of deaths from subacute myelo-optico neuropathy (SMON) were studied in a prospective cohort of 4,329 SMON patients followed for 3 years and 7 months (Sept. 1985-March 1989) with the following findings: (1) Recent excess deaths of SMON patients was estimated as 4% from ratio of O/E (SMR = 104) and deaths due to SMON itself was 6.4%. (2) The ratio of O/E was significantly higher for deaths from cancer of colon/rectum in females, cancer of pancreas in males, hypertension in males, pneumonia/influenza in females, chronic obstructive pulmonary diseases in males, tuberculosis and intestinal obstructive disease in males and females. (3) The ratio of O/E was 1.8 times or greater for those SMON patients with complications of cerebrovascular disease, severe blindness, complete loss of ambulation, and who were bedridden, and who are unable to receive home care from family members or trained home helpers.

Cause of Death↗
PubMed1991

Intracavitary drainage procedure for giant bullae in compromised patients.

Two cases of giant bullae were treated by intracavitary suction and drainage procedure under local anesthesia because of the poor pulmonary function. After staged bullectomy, the patients returned to normal life. The first case was admitted to our intensive care unit (ICU). Tube drainage was performed in the giant bulla of the left lung immediately after admission. One month after recovery from right heart failure and mediastinal shift to the right side, bullectomy was performed using linear stapler. The patient was discharged 20 days later. The second case was admitted with severe dyspnea and bilateral giant bullae were noticed. We performed tube drainage for larger bulla of the left lung under local anesthesia. Two months later, bullectomy was performed on the right side, because the bulla on the left side became smaller and the general condition of the patient improved. The patient was discharged three months later on foot and has since been asymptomatic. Giant bulla is a well-established clinical entity which includes abnormal dilatation of various parts of the tracheo-bronchial tree and other discrete sacs originating from the interstitial portion of the lung. Giant bullae are frequently associated with marked dyspnea and emphysematous symptoms. However, these symptoms depend upon various factors: size, location, valvular mechanism, condition of the contiguous lung parenchyma and the changes that may take place in the intrathoracic pressure.

Aged↗
PubMed1991

[Laparoscopic laser cholecystectomy: a prospective analysis of 70 initial cases].

Laparoscopic cholecystectomy using Nd-YAG laser was performed in 70 consecutive patients with preoperatively symptomatic gallstones. Sixty-eight patients had successful completion of the laparoscopic cholecystectomy. Mean hospital stay was 7.8 days (range: 4-12), and a diet as well as physical walking was tolerated in all 68 patients by the next day following the procedure. Mean operating time was 216 minutes in the initial 10 cases, which improved significantly to 87 minutes in the latest 28 cases. The difference of operative time did not influence any difference on the postoperative course. Nineteen of 68 patients (27.9%) required postoperative pain medication (pentazocine 15 mg, i.m.). Two patients required conversion to open cholecystectomy because of a pin hole injury on the portal vein by laser quartz in the first case, and difficult dissection due to severe adhesion in the 46th case. There is a definite learning curve in this new modality. Laparoscopic cholecystectomy is a safe and effective procedure, significantly improving the quality of life of the patients with gallstones.

Adult↗
PubMed1991

Hyperreninemic hypoaldosteronism due to hepatocellular carcinoma metastatic to the adrenal gland.

Metastases to the adrenal glands are common in patients with cancer, but among those affected, hyperreninemic hypoaldosteronism is noted very rarely. A case of hyperreninemic hypoaldosteronism secondary to metastatic hepatocellular carcinoma is reported. Laboratory data revealed selective aldosterone deficiency with hyperreninemia. Biopsy documented replacement of the adrenal glands with metastatic hepatocellular carcinoma. A review of the literature disclosed that the present case was an extremely rare one of its kind.

Adrenal Gland Neoplasms↗
PubMed1991

Experimental evaluation of myocardial protective effect of prostacyclin analog (OP-41483) as an adjunct to cardioplegic solution.

A stable prostacyclin analog (OP-41483) was evaluated for myocardial protective effect against global ischemia with the use of cardioplegia. Isolated canine hearts (n = 25) were exposed to 60 minutes of warm (37 degrees C) global ischemia after the arrest by crystalloid cardioplegia. Prostaglandin analog was given in three different ways: preadministration (700 ng/kg body weight per minute) before ischemia for 30 minutes (group I, n = 5), given as a component of cardioplegic solution (600 ng/ml, group II, n, = 6), and post-administration (25 ng/kg body weight per minute) during reperfusion for 30 minutes (group III, n = 7). During reperfusion, coronary sinus blood flow, 6-keto-prostaglandin F1 alpha in coronary sinus blood, and myocardial oxygen consumption were measured during reperfusion. As a result, groups II and III showed significantly better global left ventricular function (developed pressure, maximum dP/dt, and diastolic compliance) than the control group (without prostaglandin analog, n = 7) and group I. Myocardial oxygen consumption at reperfusion (1 minute) was significantly larger in group II than in the control group. 6-keto-prostaglandin F1 alpha flux was significantly larger in group II than in the other three groups during reperfusion. The results indicated that prostaglandin analog has a beneficial effect on myocardial protection under global ischemia with cardioplegia, particularly when used as a component of cardioplegic solution and also during reperfusion. The mechanism may relate to the cytoprotective effect (including protection of endothelium with enhanced endogenous prostacyclin production at reperfusion and also to the modulation of reperfusion per se.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Loss of alkalophily in cell-wall-component-defective mutants derived from alkalophilic Bacillus C-125. Isolation and partial characterization of the mutants.

The cells of alkalophilic Bacillus sp. C-125 are shaped by peptidoglycan and enclosed by two acidic polymers (teichuronic acid and teichuronopeptide), which bind to the peptidoglycan. Three kinds of mutant strains defective in these acidic polymers were isolated from the strain C-125. These mutants grow poorly at alkaline pH to extents related to the degree of defect in the polymers, suggesting that these acidic polymers are essential for growth in an alkaline environment. These polymers may diminish penetration of hydroxide ions.

Bacillus↗
PubMed1990

Structural changes of Kupffer cells in rat liver following experimental thermal injury.

Changes in plasma haemoglobin levels and morphology of Kupffer cells were studied in rats following lethal thermal injury. Severe haemolysis was observed immediately after thermal injury. The plasma haemoglobin levels rapidly increased to a maximum level 15 min after injury and then rapidly decreased with time. However, the values were still higher 5 h after injury than those found before injury. Soon after burning the Kupffer cells phagocytized not only circulating cell debris including erythrocyte membranes and degenerate leucocytes but also large amounts of haemoglobin. The degradation of phagocytized haemoglobin was relatively slow compared to that of other cell debris. This phagocytized haemoglobin is considered to inhibit the generation of bactericidal-free radicals and to depress Kupffer cell function. The number of Kupffer cells was markedly decreased 5 h after thermal injury, and probably relates to the persistent depletion of the reticuloendothelial system function which follows lethal thermal injury. In contrast to the decreased number of Kupffer cells, a small number of monocytic cells appeared in the sinusoidal spaces and adhered to the endothelial cells. These monocytic cells may transform into Kupffer cells.

Animals↗
PubMed1990

Determination of disulfoton and its metabolites in the body fluids of a Di-Syston intoxication case.

Disulfoton and its metabolites, two sulfoxides and two sulfones, in the body fluids of a patient who had ingested Di-Syston were analyzed by FPD-GC and GC/MS. After the chemicals in the extract (Fraction 1) obtained by Extrelut column extraction were analyzed, disulfoton and sulfoxides in Fraction 1 were oxidized into sulfones. The sulfones in the extract (Fraction 2) obtained by Extrelut column extraction were analyzed and the estimated concentrations of metabolite were calculated. The concentrations of disulfoton and the sum of the metabolites in the blood collected on admission were 0.093 nmol/g (25.4 ng/g) and 4.92 nmol/g (corresponding to 1.35 micrograms/g of disulfoton), respectively. These concentrations appear to indicate a severe level of disulfoton intoxication.

Aged↗
PubMed1990

Determination of dimethoate in blood and hemoperfusion cartridge following ingestion of formothion: a case study.

A 57-year-old male who had ingested not more than 22 g of formothion was semicomatose on admission to hospital, approximately 1.5 h after ingestion. Dimethoate, a hydrolyzed formothion, was found in blood samples collected from the patient and in the charcoal column in the direct hemoperfusion cartridge which was used 6 to 7.5 h after ingestion. It was extracted and purified by Extrelut column extraction. A gas chromatograph, equipped with a flame photometric detector and a gas chromatograph-mass spectrometer, were used to detect and confirm the presence of dimethoate. The blood dimethoate concentrations which were taken approximately 1.5 and 6 h after ingestion were 21.4 and 12.7 micrograms/g, respectively. A blood dimethoate concentration of 21.4 micrograms/g would appear to indicate a high level of formothion intoxication. The total amount of dimethoate found in the charcoal column used was 15 mg.

Adsorption↗
PubMed1990

Gas chromatographic determination of cresols in the biological fluids of a non-fatal case of cresol intoxication.

A simple and rapid method for analysis of free and conjugated cresols in biological fluids was developed. Prior to and following freeing of the conjugated cresols by acid hydrolysis in a sealed ampoule, free cresols were extracted by Extrelut column extraction, determined by gas chromatography, and confirmed by gas chromatography-mass spectrometry. In a non-fatal case of cresol intoxication a 46-year-old male had ingested about 100 ml of a saponated cresol soap solution. The concentrations of xylenol (2,4- and/or 2,5-dimethylphenol) and p- and m-cresol in the serum sample collected on admission were 15.8 micrograms/g, 43.3 micrograms/g and 73.8 micrograms/g, respectively. The total cresol concentration of 117 micrograms/g in the serum is within the range of fatal concentrations, and it is suspected therefore that the patient's recovery was due to adequate therapy alone.

Chromatography, Gas↗