Biomedical subjects

K Ohta

Publications and source records attributed to K Ohta.

At least 289 records · Page 16Linked to original sources

PubMed1998

Peripheral blood stem cell transplantation for non-Hodgkin's lymphoma in complete remission.

High-dose chemotherapy with PBSCT as consolidation therapy was administered to 15 patients with non-Hodgkin's lymphoma admitted to our department between November 1991 and March 1998. The average number of CD34-positive cells harvested was 3.1 x 10(6)/kg and the median time to a granulocyte count above 500/microliter was 12.8 days. Of the patients, one died from cytomegalovirus pneumomonia after WBC count recovered, 2 relapsed, and 12 patients are still alive and disease-free. The average disease-free survival period was 50.0 months. Stem cell harvesting is relatively simple and hematopoietic recovery is mory rapid with PBSCT than with ABMT. Our findings suggest that PBSCT can be used for consolidation therapy in NHL patients who have achieved complete remission with standard chemotherapy.

Adolescent↗

PubMed1998

[Factitious anemia with severe iron deficiency caused by self-venesection].

A 22-year-old unmarried female student of nurse school was admitted to our hospital because of hypochromic anemia and fever of unknown origin. She was diagnosed as having iron-deficiency anemia and was treated with iron, but progressive anemia recurred periodically. In particular, rapidly progressive anemia was observed after the patient stayed overnight, so we strongly suspected factitious anemia. A search of her locker in the sickroom and her room at home revealed many syringes, injection needles and a bottle of blood. Factitious anemia was diagnosed and she confessed to self blood-drawing. After a psychiatric consultation, anemia tended to to resolve gradually. However she did not go to the hospital after 6 months from her discharge. Physicians should consider factitious anemia in a patient with severe chronic hypochromic anemia who dose not respond to adequate iron therapy, particularly in a patient with medical training.

Adult↗

PubMed1998

[The management of slit-like ventricle with the Medos programmable Hakim valve and the ventriculofiberscope].

A slit-like ventricle is one of the serious complications which can occur after a shunting operation. Low pressure valve systems are usually applied for hydrocephalus during infancy. As a result the shape of the ventricle often becomes slit-like after the operation. Many shunt dependent children with slit-like ventricles have to undergo shunt revisions repeatedly. From April 1995 to February 1997 the authors used the Medos programmable Hakim valve system for 20 hydrocephalic children with slit-like ventricles who had been suffering from multiple shunt problems. The patients ages at the operation were between 3-16 Male:Female was 12:8. Follow up periods were 10-20 months. In 12 of 20 patients the shunt revisions were performed at the time of shunt dysfunction and the valve pressure levels were able to be set at the highest levels without the appearance of any symptoms. In this group the size of all the ventricles had become slightly enlarged. In the other 8 patients the operations were performed for fear of other troubles arising if shunt revisions were neglected. In this group the valve pressure levels were set with reference to the intraoperative ICP. It took a relatively long period to elevate the valve levels. Shunt dysfunction due to obstruction of the ventricular catheter was seen in one case but the symptom was not so severe and the catheter which had firmly adhered to the choroid plexus was removed endoscopically. In 2 cases of this series the shunt systems were successfully eliminated. The authors report the method and efficacy of their series using the Medos programmable Hakim valve system and a newly developed ventriculofiberscope for the slit-like ventricle of children.

Adolescent↗

PubMed1998

[Acute myelogenous leukemia with hyperkalemia induced by pentamidine administration].

A 27-year-old male with acute myelogenous leukemia received an allogeneic bone marrow transplantation (allo-BMT). Pneumocystis carinii pneumonia developed on day 65 after the allo-BMT. The patient was intravenously treated with pentamidine. This resulted in a prompt improvement of his dyspnea and fever, but hyperkalemia occurred during the pentamidine therapy. Treatment with pentamidine was stopped and emergent treatment was started. Nevertheless, the serum potassium level rose to 7.7 mEq/l. Urgent dialysis was performed and the serum potassium level fell to 5.0 mEq/l after treatment. Careful monitoring of the serum potassium level is recommended during intravenous therapy with pentamidine.

Adult↗

PubMed1998

Debridement arthroplasty for osteoarthritis of the elbow.

For treatment of osteoarthritis of the elbow, the authors use debridement arthroplasty with a medial or lateral approach. Thirty-eight elbows in 36 patients treated with this procedure were examined. The age of the patients ranged from 20 to 71 years, with a mean age of 41.7 years. Cubital tunnel syndrome was present in 16 of the 38 (42%) elbows. The operations were performed through a lateral approach in four elbows, a lateral approach with medial skin incision for ulnar nerve neurolysis in 16 elbows, a medial approach in 10 elbows, and a medial plus a lateral approach in eight elbows. The followup ranged from 2 years to 12.1 years, with an average of 5.9 years. Complete pain relief or minimal elbow pain was reported in 95% of patients who had surgical treatment. The average gain in motion was 6 degrees extension and 18 degrees flexion. Results for the various surgical approaches did not show a statistically significant difference. Recurrence of bony spurs and ridges was analyzed additionally in 18 selected patients who could be observed more than 5 years after surgery (range, 5-12 years). Redevelopment of bony spurs on the coronoid process and olecranon tip occurred in all 18 patients, but those changes were graded as mild in 13 (74%) patients and moderate in five (16%) patients and were accompanied by no pain or slight pain. Elbow arthroplasty as used by the authors produces stable and reliable results for relief of pain, gains in range of motion, and the absence of recurrence of significant osteoarthritis.

Adult↗

PubMed1998

Drug eruption due to Bufferin showing erythema exsudativum multiforme with a photo-recall-like phenomenon.

A 21-year-old woman who had been taking several kinds of analgesics to treat dysmenorrhea developed episodic attacks of a purpuric macular eruption and a burning sensation on unexposed areas of the upper chest and back where she had sustained severe sunburn eight months earlier. Target-like lesions developed on these areas after intake of Bufferin, a combination of aspirin and dialuminate. After the eruptions had abated following systemic administration of a corticosteroid agent, a challenge test was performed, using a quarter of a tablet of Bufferin. The patient developed a temporary burning sensation and a erythematous color on the previously sunburned skin. We diagnosed this case as a drug eruption due to Bufferin showing erythema exsudativium multiforme with a photo-recall-like phenomenon. In our case, skin tests would be useful to confirm the causal drug.

Adult↗

PubMed1998

The mechanism of sensitizing effect of a triazine dye, cibacron blue F3GA, on methicillin-resistant Staphylococcus aureus to oxacillin.

We recently found that a triazinyl dye, cibacron blue F3GA (CB), has a sensitizing effect on the in-vitro susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) to oxacillin (C. Shirai, M. Sugai, H. Komatsuzawa, K. Ohta, M. Yamakido, H. Suginaka, Antimicrob. Agents Chemother. 42: 1278-1280, 1998). Among nine triazinyl dyes tested, CB the strongest sensitizing effect. Population analysis demonstrated that CB reduced the resistance level of MRSA. In the presence of oxacillin at subinhibitory concentrations, CB inhibited the growth of MRSA, but its effect on the cells appeared to be bacteriostatic. Under experimental conditions, CB did not affect the amount of PBP2', binding of [14C]benzylpenicillin to PBP2', or peptidoglycan susceptibilities to bacteriolytic enzymes. Autolytic enzyme-deficient MRSA mutants were equally as sensitive as the parent strain to the effect of CB on the susceptibility to oxacillin. CB affected the resistance level of MRSA irrespective of the status of the mecI/mecR1 element and/or penicillinase plasmids. The sensitivities of several bacteriolytic enzymes to heat-inactivated MRSA cells were not affected when the cells grown in the presence of CB. CB did not stimulate the release of lipoteichoic acid from the cells. These results suggest that the sensitization effect of CB cannot be simply explained by its effect on mecA related products, autolysins, femAB products or the release of lipoteichoic acid.

Coloring Agents↗

PubMed1998

[A case of severe cytomegalovirus infection after the repair of coarctation of aorta].

We report a 2-month-old boy without any immuno-compromised diseases, who suffered from the severe cytomegalovirus (CMV) infection after the subclavian flap aortoplasty and pulmonary artery banding for coarctation complex. He underwent the operation at 2 months old and received 2 units of irradiated packed red blood cells before and after the surgery. His postoperative course was uneventful but the interstitial pneumonitis, until he developed watery diarrhea 10 days after the surgery following hepatitis with the marked hepatomegaly 3 weeks after. Since CMV infection was confirmed as the cause of the pneumonitis, enterocolitis and hepatitis, he was initially treated by gamma-globulin with the high CMV titer at a dose of 200 mg/kg/day for 2 days and ganciclovir at a dose of 10 mg/kg/day for 14 days. Because of the persistent CMV infection, he needed two more treatments of ganciclovir at the same dosage and gamma-globulin once a week for 2 months. He finally recovered from severe CMV infection 5 months after the above treatments. In conclusion, the severe CMV infection can occur by blood transfusion even in the surgical case with normal immune system. If one finds pneumonitis, hepatitis or enterocolitis after any type of surgery with history of blood transfusion, CMV infection should be suspected as the cause of these diseases.

Antiviral Agents↗

PubMed1998

[Multiple cerebral infarction associated with cerebral vasculitis in rheumatoid arthritis].

A 64-year-old woman was suffering from rheumatoid arthritis since the age of 57. At the age of 62, she manifested episcleritis of the eyes and rheumatoid nodules in the skin, and rheumatoid factor in the blood became high. These findings indicated the presence of systemic vasculitis, and she was treated with prednisolone. At the age of 64, she suddenly became delirious, and T2-weighted and diffusion-weighted MR images revealed fresh infarctions in bilateral temporal and parietal lobes of the cerebrum. MR angiography failed to show any narrowing or obstruction of large cerebral arteries. She had also high fever and arthralgia, and her blood showed elevated levels of white blood cells, erythrocyte sedimentation rate, C-reactive protein, IgG-rheumatoid factor and immune complex. Lumbar puncture revealed an elevated protein level in CSF. A daily dose of 60 mg prednisolone ameliorated these clinical and laboratory findings as well as her consciousness, disclosing disturbances in higher cortical functions including Wernicke aphasia, disorientation, and ideomotor, ideational, and constructional apraxia. Previous 13 reported cases of cerebral infarction complicating rheumatoid vasculitis were mostly described as showing multiple infarctions in cerebral hemisphere, disturbance of consciousness, elevated protein in CSF, and effectiveness of steroid therapy. The present case had these characteristics, and the cerebral vasculitis mediated by IgG-rheumatoid factor and immune complex was indicated as a probable cause of multiple cerebral infarctions.

Arthritis, Rheumatoid↗

PubMed1998

Problems with assays based on fibrin clot formation principle: analysis of multilaboratory data.

In order to investigate the inter-laboratory differences of coagulation assays, three different control plasmas were distributed for coagulation assays to 162 institutes. Three types of coagulation tests, that is, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (Fbg) assay were carried out by routine methods in each institute. In our laboratory, the Fbg concentrations were measured in two different plasmas using one instrument and nine reagents, and the Fbg concentrations were measured in ten control plasmas using three instruments and one reagent. Results were obtained as follows: (1) The coefficient of variance (CV) for control plasma with the highest value was significant in the PT assay and APTT assay. (2) Inter and intra-institute differences in PT and APTT assays were observed when the reagent or the instrument used was changed. (3) Inter and intra-institute differences in PT and APTT assays were also observed when both the reagent and the instrument were changed. (4) Inter and intra-institute differences in the PT and APTT assays were observed between the manual and the mechanical methods. (5) The CVs for the Fbg assays were the largest in the plasma at the lowest concentration of the three plasmas. (6) When control plasmas of three different Fbg concentrations were assayed, the number of the institutes which obtained a value greater than 3 standard deviations (SDs) was highest for the control plasma with the lowest concentrations of Fbg, and some of the instruments were not able to measure such a low Fbg concentration. (7) When the fibrinogen concentration was measured in various kinds of commercially-available control plasmas with a calibrated instrument, the values determined were different from the assigned ones and varied significantly from instrument to instrument. From the results, we concluded that standardization of the quality of control plasma, and its value assignment to the plasma should be established as soon as possible, and that a reliable standard fibrinogen assay should be developed.

Blood Coagulation↗

PubMed1998

[Results of treatment of cancer of the cardia].

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.

Adenocarcinoma↗

PubMed1997

Effects of various types of Triton X on the susceptibilities of methicillin-resistant staphylococci to oxacillin.

We examined the effect of six types of the nonionic detergent Triton X on the susceptibilities of methicillin-resistant staphylococci to oxacillin. We used five methicillin-resistant Staphylococcus aureus isolates and 17 methicillin-resistant coagulase-negative staphylococci isolates. All strains of S. aureus, S. epidermidis and S. sciuri had enhanced susceptibility to oxacillin following exposure to the types of Triton X having 7-13 polymerized ethylene oxides. These strains were altered from homogeneously resistant to heterogeneously resistant by Triton X-100. Those types of Triton X that affected the resistance level also promoted the release of lipoteichoic acid. These results and those of previous studies suggest that Triton X might act on factors other than the mecA or femA products.

Detergents↗

PubMed1997

Nitric oxide generation from sodium nitroprusside and hydroxylamine in brain.

We aimed to demonstrate different modes of in situ nitric oxide (NO) generation from two NO donors in cerebral cortex of halothane anesthetized cats. NO donors were delivered by in vivo microdialysis into the cortical tissue where an NO electrode measured real-time changes in extracellular NO concentration. In vitro testing in Finger's solution revealed that sodium nitroprusside (SNP) liberates NO spontaneously in the presence of light, whereas hydroxylamine does not generate any NO under these conditions. Supplementation with 200 mM of the NO donors SNP and hydroxylamine evoked dose-related increases in NO concentration (52.0 +/- 6.7 nM, n = 5, and 14.0 +/- 3.8 nM, n = 5, respectively). The increase in NO concentration was significantly greater during SNP than during hydroxylamine delivery (p < 0.001). In contrast, CBF increased similarly under the influence of both NO donors. Electrocorticogram and cortical direct current potential remained unaffected. In conclusion, hydroxylamine is degraded into NO intracellularly and efficiently dilates cerebral blood vessels. SNP, in contrast, generates NO mainly in the extracellular space.

Animals↗

PubMed1997

The meiotic recombination hot spot created by the single-base substitution ade6-M26 results in remodeling of chromatin structure in fission yeast.

The G -->T transversion mutation, ade6-M26, creates the heptanucleotide sequence ATGACTG, which lies close to the 5' end of the open reading frame of the ade6 gene in Schizosaccharomyces pombe. The mutation generates a meiosis-specific recombination hot spot and a binding site for the Mts1/Mts2 protein. We examined the chromatin structure at the ade6 locus in the M26 strain and compared it to that of the wild-type and hot spot-negative control M375. Micrococcal nuclease (MNase) digestion and indirect end-labeling methods were applied. In the M26 strain, we detected a new MNase-hypersensitive site at the position of the M26 mutation and no longer observed the phasing of nucleosomes seen in the wild-type and the M375 strains. Quantitative comparison of MNase sensitivity of the chromatin in premeiotic and meiotic cultures revealed a small meiotic induction of MNase hypersensitivity in the ade6 promoter region of the wild-type and M375 strains. The meiotic induction of MNase hypersensitivity was enhanced significantly in the ade6 promoter region of the M26 strain and also occurred at the M26 mutation site. The formation of the MNase-sensitive region around the heptamer sequence was abolished by the introduction of single-nucleotide substitutions in the heptamer sequence, which also abolish hot spot activity and binding of Mts1/Mts2. These data suggest that Mts1/Mts2 binding to the heptamer sequence results in a chromatin structure suitable for the recruitment of a meiosis-specific recombination function or functions.

Chromatin↗

PubMed1997

Shared and distinct functions of RAGS and ELF-1 in guiding retinal axons.

Two ligands for Eph-related receptor tyrosine kinases, RAGS and ELF-1, have been implicated in the control of development of the retinotectal projection. Both molecules are expressed in overlapping gradients in the tectum, the target area of retinal ganglion cell axons. In two in vitro assays ELF-1 is shown to have a repellent axon guidance function for temporal, but apparently not for nasal axons. RAGS on the other hand is repellent for both types of axons, though to different degrees. Thus, RAGS and ELF-1 share some and differ in other properties. The biological activities of these molecules correlate with the strength of interaction with their receptors expressed on RGC axons. The meaning of these findings for guidance of retinal axons in the tectum is discussed.

Animals↗

PubMed1997

Inhibition of nitric oxide synthase causes cardiac phenotypic modulation in rat.

Cardiac gene expressions of collagen and contractile proteins were examined in rats treated with a nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), for 3 weeks. The rats became hypertensive, which caused left ventricular hypertrophy. Among the mRNAs examined, beta-myosin heavy chain was increased and alpha-myosin heavy chain was decreased in both left and right ventricles, whereas skeletal alpha-actin and atrial natriuretic polypeptide were increased in the left ventricle only. Furthermore, coadministration of losartan with L-NAME lowered blood pressure and caused regression of left ventricular hypertrophy, but did not affect beta- and alpha-myosin heavy chain mRNA levels, indicating that L-NAME directly regulates beta- and alpha-myosin heavy chain mRNA.

Angiotensin II↗

PubMed1997

Involvement of reactive oxygen intermediates in spontaneous and CD95 (Fas/APO-1)-mediated apoptosis of neutrophils.

Apoptosis is well known to be mediated by oxidative stress. To evaluate the functional role of reactive oxygen intermediates (ROI) produced by neutrophils, we compared the rates of apoptosis in neutrophils isolated from normal donors and from patients with chronic granulomatous disease (CGD), a hereditary defect in ROI production. Spontaneous cell death in CGD neutrophils in vitro was significantly inhibited relative to normal neutrophils. The acceleration of apoptosis induced by anti-Fas monoclonal antibody (MoAb) in CGD neutrophils was much slower than that seen in normal neutrophils. These findings suggest that the apoptosis of neutrophils may be mediated by endogenous oxidative products. This suggestion was confirmed by observation that apoptosis of normal neutrophils was markedly inhibited by reduction of intracellular levels of hydrogen peroxide (H2O2). The inhibition of apoptosis in normal neutrophils by adding catalase occurred regardless of the presence of anti-Fas MoAb. H2O2 increased both spontaneous apoptosis and Fas-mediated apoptosis of the CGD neutrophils in proportion to that seen in normal neutrophils. Although several factors that mediate the apoptosis of neutrophils remain to be determined, these results suggest that ROI are major mediators of the apoptosis in neutrophils and may be involved in Fas-mediated signal transduction pathway.

Apoptosis↗

PubMed1997

Flow cytometric analysis of cell surface antigen recognized by monoclonal antibody (MSN-1) in normal, hyperplasia, and carcinoma of endometrial cells: its diagnostic value for endometrial carcinoma.

A monoclonal antibody, MSN-1, was used for flow cytometric analysis of cells from normal endometrium, endometrial hyperplasia, and endometrial carcinoma. The 90th percentile of the specimen control was used as a threshold. Reactivity was defined by the percentage of stained cell about the thresholds, adjusted for the expected percentage. A sample was considered positive if the reactivity exceeded 10%. The positivity rate for normal endometrium, endometrial hyperplasia, and endometrial carcinoma specimens was 9.2%, 19.2%, and 84.6%, respectively. The mean (+/-SD) reactivity rate of MSN-1 for normal endometrium, endometrial hyperplasia, and endometrial carcinoma was 3.3 +/- 6.2%, 7.4 +/- 13.8%, and 34.4 +/- 24.2%, respectively. There was a significant difference of the reactivity rates between normal endometrium and endometrial hyperplasia, and between endometrial hyperplasia and endometrial carcinoma (P < 0.01). In the subgroup of endometrial carcinoma patients with confined muscular invasion, the reactivity and the positivity rates were also analyzed. There was no relationship between the depth of muscular invasion and the reactivity rate or the positivity rate. In endometrial carcinoma patients who simultaneously underwent endometrial cytology, the relationship of the results of cytology and the positivity rate was also analyzed. When the results of cytology and flow-cytometric analysis were combined, the positivity rate of endometrial carcinoma was 100% (30/30). In conclusion, flow-cytometric analysis of endometrial cells employing MSN-1 could be a useful supplementary diagnostic method for endometrial carcinoma.

Animals↗