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Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 631 records · Page 35Linked to original sources
PubMed1993

[The relationship of periventricular hyperintensity with cerebral blood flow and cerebrovascular reserve capacity in asymptomatic individuals].

Although periventricular hyperintensity (PVH) is frequently detected in elderly persons by magnetic resonance imaging (MRI), the relationship of such lesions with cerebral blood flow (CBF) and cerebrovascular reserve capacity has never been determined. We used acetazolamide-enhanced xenon-133 CBF and MRI to study 28 subjects with one or more cerebrovascular risk factors but with no neurological symptoms. According to MRI examinations on the transaxial slice of the body of the lateral ventricle, 10 subjects had no PVH (group O), 7 a partial PVH (group I), 6 a continuous PVH (group II), and 5 a confluent PVH which spreads over a wide area of the white matter (group III). There was no relationship between the severity of PVH and the resting cortical CBF (F = 2.7). However, the severity of PVH showed significant negative relationships with the acetazolamide-enhanced CBF (F = 9.5; p < 0.01), and the absolute increase of CBF from the resting state to the acetazolamide challenge (F = 5.1; p < 0.01). Our data suggest the importance of hemodynamic factors and the compensatory vasodilation in the pathogenesis of PVH in asymptomatic individuals.

Acetazolamide↗
PubMed1993

[Proton magnetic resonance spectroscopy (1H-MRS) of peripheral blood lymphocytes in patients with sarcoidosis and interstitial pneumonitis].

We recently developed a method of proton magnetic resonance spectroscopy (1H-MRS) to measure the 1H-MR spectra of peripheral blood lymphocytes (PBL) using only 10(7) cells. We investigated the clinical feasibility of this method for evaluating disease activities in sarcoidosis and interstitial pneumonitis. PBL was separated from 10 ml of venous blood by differential centrifugation with Ficoll-Conray. Using a 90 MHz MR spectrometer (EX90, JEOL), the spectrum was obtained with 4000 times accumulation of 1H signals by single 70 degree pulses at 37 degrees C under spinning. Water signal was suppressed with the homo-gated decoupling sequence. The spectra were analyzed with Gaussian curve fitting. The spectra of patients with active disease showed significant increases in peak heights for (CH2)n and CH3 peaks compared with the control. The peak heights decreased after improvement of disease states. The changes in 1H-MR spectra suggested activation of PBL in patients with sarcoidosis and interstitial pneumonitis, since similar changes have been shown for cells activated with mitogens. Our preliminary results indicate that 1H-MRS may be useful to evaluate activation of PBL in sarcoidosis and interstitial pneumonitis.

Adult↗
PubMed1993

Elevation of phospholipase A2 protein in sera of patients with Crohn's disease and ulcerative colitis.

The protein mass of group II phospholipase A2 (PLA2) levels were immunochemically measured in sera of 43 patients with Crohn's disease (CD), 43 patients with ulcerative colitis (UC), and 35 healthy volunteers, and compared with PLA2 enzymatic activity. Serum immunoreactive group II PLA2 (IR-PLA2 II) levels of active CD patients were significantly higher than those of the controls and inactive CD patients. Serum IR-PLA2 II levels were also significantly greater in patients with severe UC and moderate UC than in the controls and patients with mild UC. Serum IR-PLA2 II levels were found to be closely correlated with serum PLA2 activity in patients with CD and UC. Serum IR-PLA2 II levels and PLA2 activity decreased by antiinflammatory treatment in six patients with CD and two with UC. These results suggest that serum IR-PLA2 II levels can be a useful parameter in the evaluation of disease activity of CD and UC, and that elevated PLA2 enzymatic activity in sera of patients with CD and UC is attributable to increased protein concentration of group II PLA2, in agreement with our previous results.

Adolescent↗
PubMed1993

[A study of toxicities and complications observed in alternating non-cross-resistant chemotherapy (CAMBO-VIP) for non-Hodgkin's lymphoma].

Thirty-nine patients with non-Hodgkin's lymphoma were treated with weekly alternating non-cross-resistant chemotherapy (CAMBO-VIP). We obtained a high response rate, and prolonged disease-free survival with side effects and complications of various severity were observed. Three patients were withdrawn from the study due to aggravation of liver cirrhosis, cerebral infarction, and poor tolerance. Thirty-six patients completed this 12-week intensive chemotherapy. The median treatment delay in all patients was 3 days (-4 to 29 days), and a delay of over 15 days was seen in 5 patients. The nadir of the neutrophil count was 0 to 2,100/microliters (median 140/microliters), and 15 patients were below 100/microliters. Two patients had pneumonia and 4 had herpes zoster infection. The platelet count nadir was 20,000 to 240,000/microliters (median 90,000/microliters). Ten patients were below 50,000/microliters, but none required platelet transfusion. Red cell transfusion was given in 6 patients. Elevation of transaminases was seen in 25 patients, but it was not serious except for a patient with liver cirrhosis. The elevation of serum LDH level and decrease of serum haptoglobin level seen shortly after completion of treatment seemed due to the increased blood cell destruction. Stomatitis was observed in 32 patients, 17 of whom showed more than grade 3 toxicity. Blister formation on palms and/or soles was noted in 6 patients. There was no treatment-related death observed.

Adolescent↗
PubMed1993

[Idiopathic bilateral sensorineural hearing loss: clinical study of cases with rapidly progressed deafness].

In a series of 127 patients with idiopathic bilateral sensorineural hearing loss (IBSH) at the Hearing Clinic in the Department of Otolaryngology, Kitasato University Hospital, 20 cases showed rapid progression of hearing impairment. These patients had been treated with the same therapeutic regimen used in sudden deafness (S.D.). Improvement of hearing loss after treatment was generally less effective in the cases with rapidly progressed IBSH than in the cases with S.D. However, hearing improvement was achieved in some cases with rapidly progressed IBSH when the treatment had started in the early stages after the onset of rapidly progressive hearing loss. The mode of fluctuating hearing loss in the cases with rapidly progressed deafness was assumed to be similar to that in the group of all cases with IBSH.

Adolescent↗
PubMed1993

[Brain protection on the aortic arch replacement--with deep hypothermic selective cerebral perfusion via right axillary artery].

Graft replacement was performed in the treatment of 31 patients with aneurysm involving the aortic arch from May, 1986 to December, 1992. Of the 31 patients, 16 had true aneurysm, 13 had aortic dissection and 2 had Annuloaortic ectasia. From May 1986 to May 1989, we did not have the policy about brain protection. Since June 1989, we performed the aortic arch surgery with deep hypothermic selective cerebral perfusion via right axillary artery and used open distal anastomosis technique. Besides, we exchanged the perfusion site to the ascending aorta when we finished the selective cerebral perfusion. In that way, brain complication rate was decreased from 57.1% to 11.7% and operative mortality was decreased from 85.7% to 29.1%.

Aged↗
PubMed1993

[A case of multiple ureteral polyps treated with ureteroscopy].

We report a case of multiple ureteral polyps treated with a rigid ureteroscope in a 27-year-old man with the chief complaint of left lower abdominal pain. The patient, who had left renal stones pointed out on his plain film, was referred for further examination and treatment of left hydronephrosis as suggested by drip infusion pyelography (DIP). DIP and retrograde pyelography (RP) revealed left hydronephrosis and a filling defect in the upper third of ureter. An ureteroscopic inspection and biopsy was conducted. The pathological diagnosis was fibroepithelial polyps of the ureter, so we performed an ureteroscopic polypectomy for the treatment. The postoperative course has elapsed favorably, without ureteral stricture or recurrence of the polyps. Ureteroscopic procedures are considered to be useful for the preoperative diagnosis and treatment of ureteral polyps.

Adult↗
PubMed1993

[The effects of pharmacological autonomic blockade on the conduction system in patients with and without sinus node dysfunction].

Electrophysiological studies were performed in 26 patients with sick sinus syndrome (SSS) and 12 controls before and after pharmacologic autonomic blockade (PAB) with propranolol (0.15 mg/kg) and atropine (0.04 mg/kg). Sinus cycle length (SCL) shortened significantly after PAB in both groups. PA and HV intervals did not change after PAB. AH interval shortened and Wenckebach period increased after PAB in SSS group. Maximum corrected sinus node recovery time shortened in the control group but did not change in the SSS group after PAB. Calculated sinoatrial conduction time shortened after PAB in both groups. Refractory periods of the atrioventricular (AV) node and the ventricle shortened significantly, but those of the atrium did not change after PAB. Linear relations existed between the change of SCL and the change of AH interval and of the Wenckebach period. These results suggested that the autonomic nervous system had the same effects on the sinus and the AV nodes in patients with SSS, and that parasympathetic tone was predominant on the sinus node, the perinodal tissue and the AV node under resting conditions.

Atropine↗
PubMed1993

[A case of pulmonary tuberculosis complicated with drug toxicosis--value of shosaikoto and hochuekito as anti-allergic agents].

A clinical course of pulmonary tuberculosis was reported about adverse reaction of anti-tuberculous chemotherapy. A fifty-eight-year-old male patient was complicated with agranulocytosis induced by RFP, hepatic dysfunction and systemic eruption induced by INH, and high fever induced by SM. Adjuvant therapy with Shosaikoto and Hocheukito suppressed INH induced hepato-dermatological toxicosis moderately and suppressed SM induced high fever completely. By these anti-allergic therapy, combined chemotherapy with SM, EB, PAS and PZA became possible during more than six months, and chemotherapeutic effect was marked. This case report suggested possibility and significance of those Kampo agents against serious allergic reaction complicated with the chemotherapy for pulmonary tuberculosis.

Antibiotics, Antitubercular↗
PubMed1993

[Rearrangements of immunoglobulin light chain and heavy chain constant region genes in B-cell malignancies].

We analyzed immunoglobulin (Ig) gene rearrangements in 69 patients with B-cell malignancies by Southern hybridization. We used 5 probes which covered JH 5'S mu and S gamma 3 loci of the Ig heavy (IgH) chain gene, and C kappa and kappa de loci of the Ig light (IgL) chain kappa gene, respectively. DNA rearrangements were observed in 68 out of the 69 patients using the JH probe. In 97% (33/34) of patients with non-Hodgkin's lymphoma (NHL), 100% (5/5) of chronic lymphocytic leukemia (CLL), 42% (10/24) of non-T cell acute lymphoblastic leukemia (non-T ALL), and in 0% (0/4) of chronic myelogenous leukemia lymphoid crisis (CML-LBC), the rearrangements were detected by C kappa and/or kappa de probes. Furthermore, the genotype of the light chain was defined by rearrangement patterns of these 2 probes. The by using the 5'S mu-probe, class switch recombinations were detected in 76% (25/33) of NHL, 20% (1/5) of CLL, 17% (4/24) of non-T ALL, and in 0% (0/4) of CML-LBC. Among them, 1 case of IgM NHL and 3 cases of double bearer NHL had rearranged on both IgH alleles by the constant region. The results of this study indicate that genotypes correspond well to phenotypes of B-cell malignancies and that the determination of genotype will be useful for making an exact diagnosis of B-cell malignancies.

DNA, Neoplasm↗
PubMed1993

[Treatment of advanced gastric and colorectal cancer with 5-FU, leucovorin and interferon-alpha].

Twenty-four patients with advanced or relapsed gastric or colorectal cancer were treated with a combination of 5-fluorouracil (5-FU), leucovorin (LV) and interferon-alpha (IFN-alpha). 5-FU was administered by rapid intravenous infusion at 350 mg/m2 for 5 consecutive days. Intravenous bolus administration of LV 20 mg/m2 was given before each 5-FU administration. This combination was repeated every 3 to 4 weeks. IFN-alpha (HLBI), 6MU, was administered subcutaneously daily. Of 13 patients with gastric cancer, there were 2 PR, 4 NC and 7 PD, and among 11 patients with colorectal cancer, there were 1 CR, 8 NC and 2 PD. All 16 previously treated patients had no clinical response. Responses were seen in patients with no prior chemotherapy and with good performance status. Most common toxicities observed were leucopenia, fever, stomatitis and diarrhea, which were all tolerable and reversible.

Adult↗
PubMed1993

Induction of tolerance to crotoxin in mice.

Crotoxin, the major toxic component from the venom of Crotalus durissus terrificus is a potent neurotoxin (LD50, i.p., mice, 0.09 mg/kg) which possesses phospholipase A2 activity and causes a blockade of neuromuscular transmission. In this article, we show that mice injected daily with progressively increasing doses of crotoxin develop tolerance to the lethal action of this toxin. Treated mice tolerated daily doses of crotoxin 20- to 35-fold higher than the original LD50 without the characteristic signs of toxicity. Studies on the isolated phrenic nerve-diaphragm preparation in vitro from control (crotoxin-naive) mice showed that the exposure to 2 to 10 micrograms/ml crotoxin in the bath produced complete transmission blockade in 120 to 150 min. Conversely, the preparations from crotoxin-treated mice required crotoxin concentrations in the range of 17.5 to 100 micrograms/ml to produce complete neuromuscular block, being virtually insensitive during 200 min of exposure to 5 to 10 micrograms/ml crotoxin. Phrenic nerve-diaphragm preparations of control (crotoxin-naive) and crotoxin-treated mice did not show significant differences in sensitivity to the blocking action of carbamylcholine, suggesting that induction of tolerance to crotoxin is likely a presynaptic event.

Animals↗
PubMed1993

[Experimental study on comparative efficacy of hepatic arterial injection of anticancer agent under temporary occlusion of portal vein].

To compare the efficacy of intra-hepatic arterial infusion of anti-cancer drug under temporary occlusion of portal vein, the following two experiments were performed. 1. VX2 tumor cells (about 1 x 10(5) cells) were transplanted through the superior mesenteric vein of the rabbits, after 2 weeks, 4'-0-Tetrahydropyranyl doxorubicin (2 mg/kg, 2 ml) aqueous solution (THP) was administered into hepatic artery of rabbits with metastatic VX2 liver tumor. 2. THP was injected into hepatic artery under temporary occlusion of portal branch of median left lobe with metastatic liver. Then the THP levels of normal liver tissue and tumor of median left lobe and lateral right lobe. The THP levels of tumor under portal occlusion tended to be about 2.63-fold higher than without occlusion. These results suggest that hepatic arterial injection under portal occlusion is more useful to increase the levels of anticancer agents of metastatic liver tumor.

Animals↗
PubMed1993

Reverse-phase high-performance liquid chromatographic assay of phospholipases: application of spectrophotometric detection to rat phospholipase A2 isozymes.

This paper appraises an HPLC method for assaying phospholipase A2 (PLA2). The procedure is based on heptane-isopropanol-H2SO4 extraction of fatty acids released by the enzyme in the presence of margaric acid as an internal standard, and precolumn derivatization with 9-anthryldiazomethane. The derivatives of naturally occurring long-chain fatty acids were accurately determined by reverse-phase HPLC with ultraviolet detection at 254 nm; the fatty acids were identical with margaric acid in terms of their extraction efficiency in the presence or absence of a bile salt, reactivity with the labeling reagent, and molar extinction coefficients of their derivatives. HPLC conditions were optimized so as to separate the derivatives of palmitic and oleic acids completely within 7 min. The use of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol/cholate system as substrate proved useful for the sensitive detection of PLA2 activities in rat tissue homogenates. Distribution of immunoreactive pancreatic and group II phospholipases A2 was estimated from the degree of inhibition of enzyme activities by specific antibodies raised against either forms of phospholipase A2 isozymes. The results were consistent with those of immunoblot analyses.

Animals↗
PubMed1992

Preparation of a fluorescent derivative of benzoylecgonine, and preliminary studies of its application to the analysis of urine.

A sensitive high-performance liquid chromatographic method using 3-bromomethyl-6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone (Br-DMEQ) as a fluorescent labeling reagent is described for the determination of benzoylecgonine (BE) and ecgonine (EC). The Br-DMEQ derivatives of BE and EC were separated on a C18 column and detected at 455 nm with excitation at 370 nm. The detection limits of the proposed method were 18.7 fmol for BE and 12.5 pmol for EC at a signal-to-noise ratio of 3. Relative standard deviations of five replicate measurements were 1.94% (10 pmol) and 2.98% (50 pmol) for BE and 6.3% (250 pmol) and 5.62% (1.25 pmol) for EC. This method was applied to the determination of BE in human urine. BE was extracted from urine by solvent extraction with chloroform-isopropyl alcohol (9:1, v/v) solution. Levels of 2.5.10(-8) M BE in urine (25 pmol/ml) could be determined.

Chromatography, High Pressure Liquid↗
PubMed1992

[Results of radiation therapy of extrahepatic bile duct carcinoma].

From January 1975 to August 1988, 40 patients with extrahepatic bile duct carcinoma were treated by external irradiation at Chiba University Hospital and the National Medical Center Hospital. Thirty-four patients (male: 20, female: 14) were evaluable. Eighteen patients were postoperative cases because the surgical margin was positive for tumor cells in the postoperative pathological examination; the other 16 were inoperable cases. Survival in postoperative and inoperable cases was not significantly different, with median survival times of 13.8 and 8.1 months, respectively. Survival in the recanalization-positive and negative-groups was significantly different (p less than 0.05) after irradiation, with median survival times of 13.5 and 6.0 months, respectively. Complications of therapy were recognized in 68% of all cases. They were mainly gastrointestinal symptoms such as nausea, vomiting, erosive gastritis and loss of appetite, but they were not severe. Distant metastasis was recognized in only 4 patients (10%): three had bony metastasis and one had supraclavicular and pulmonary hilar lymph node metastasis. Ninety percent of all cases died from hepatic failure or peritonitis carcinomatosa due to failure to obtain local control by external irradiation. A more effective modality of treatment is necessary to cure these patients.

Aged↗