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Biomedical subjects

M Yoshida

Publications and source records attributed to M Yoshida.

At least 1,171 records · Page 65Linked to original sources

[Suppression of spontaneous AC potentials in guinea pig cochlea by external tones].

Spontaneous electrical oscillations (AC potentials) were observed in the cochlea of three guinea pigs without any exposure to noise or drugs. The AC potentials disappeared completely within one minute after the cessation of artificial ventilation, and were suppressed by presenting external tones to the ear. As the frequency of the external tone was displaced toward that of the spontaneous oscillation, the signals were increasingly suppressed. Exposure to intense tone produced residual suppression of the AC potentials for several minutes. The time course of recovery from the suppression appeared to be similar to that in the noise induced temporary threshold shift measured psychoacoustically. From these results, it was concluded that the spontaneous AC potentials in the guinea pig cochlea were generated by the active mechanical vibration system at the area on the basilar membrane where the characteristic frequency corresponded to that of the AC potentials.

Acoustic Stimulation↗

EI-1507-1 and -2, novel interleukin-1 beta converting enzyme inhibitors produced by Streptomyces sp. E-1507.

EI-1507-1 and -2, novel interleukin-1 beta converting enzyme (ICE) inhibitors, were isolated from the culture broths of Streptomyces sp. E-1507. EI-1507-1 and EI-1507-2 selectively inhibited the recombinant human ICE activity with IC50 values of 0.23 and 0.42 microM, respectively. EI-1507-1 and EI-1507-2 also inhibited mature interleukin-1 beta secretion from THP-1 cells with IC50 values of 1.1 and 1.4 microM, respectively.

Amino Acid Sequence↗

A case of Trichuris trichiura infection diagnosed by colonoscopy.

A 65-year-old Japanese female was admitted to our hospital because of right lower abdominal pain. Laboratory and roentgenological tests revealed no abnormalities. Repeated stool examinations revealed no ovum or parasite. However, colonoscopic examination demonstrated the presence of a parasite on the edematous mucosa of cecum. The adult male whipworm (Trichuris trichiura) was then removed endoscopically. Her symptoms disappeared quickly, and no additional parasite was found in the feces during or after the mebendazole treatment. Repeated stool examinations failed to show any ova, because this patient was infected by a single male parasite. Colonoscopic study should be considered a useful tool for the diagnosis of T. trichiura infection, even if no ovum is found in stool examination.

Aged↗

Activation of human monocyte functions by tumor necrosis factor: rapid priming for enhanced release of superoxide and erythrophagocytosis, but no direct triggering of superoxide release.

Tumor necrosis factor (TNF), like granulocyte-macrophage colony-stimul ating factor (GM-CSF), rapidly primed human monocytes for enhanced release of superoxide (O-2) stimulated by receptor-mediated agonists, N-formyl-methionyl-leucyl-phenylalanine (FMLP) and concanavalin A (Con A), but not by phorbol myristate acetate (PMA), which bypasses the receptors to stimulate the cells. The optimal priming was obtained by pretreatment of suspended monocytes with 10 U/mL TNF for 10 minutes at 37 degrees C. The potency of the maximal priming effect was TNF> GM-CSF, and the combined effect of TNF and GM-CSF was greater than that of each cytokine alone. GM-CSF induced an increase in cytoplasmic pH but TNF did not. These findings suggest that TNF and GM-CSF activate monocytes through different mechanisms. TNF and GM-CSF by themselves never triggered O-2 release in suspended monocytes or monocytes adherent to endothelial cells, although both cytokines triggered massive release of O-2 in human neutrophils. In additions, TNF and GM-CSF induced tyrosine phosphorylation of a 42-kD protein in neutrophils but not in monocytes. These findings suggest that the TNF-receptor- or GM-CSF-receptor-mediated signaling pathways for triggering O-(2) release is active in neutrophils but inactive or defective in monocytes. TNF also enhanced phagocytosis of sialidase-treated autologous erythrocytes by monocytes, and this effect was further potentiated in the presence of autologous fresh serum. The significant enhancement of erythrophagocytosis was obtained at 1 U/mL TNF. At this concentration of TNF, the expression of C3bi-receptor (CD11b/CD18) was upregulated. These findings show that TNF rapidly primes human monocytes for enhanced release of O-(2) and erythrophagocytosis and suggest that TNF activates monocytes through autocrine or paracrine mechanisms at the inflammatory sites inasmuch as TNF is primarily produced by activated monocytes/macrophages.

Adult↗

Evaluation of CI-973, a platinum analogue, in refractory or relapsed acute leukemia.

The purpose of the study was to define the maximally tolerated dose (MTD), major toxicities, and possible antitumor activity of CI-973 a new platinum analogue, in patients with refractory or relapsed acute leukemia. CI-973 was given as a 5-day continuous infusion every 3 to 4 weeks to patients with refractory or relapsed acute leukemia, at doses ranging from 150 mg/m2 to 1350 mg/m2 per course. Thirty-six patients were treated including 18 patients with acute myelogenous leukemia (AML), four with acute lymphocytic leukemia (ALL) and 14 with chronic myelogenous leukemia in blastic phase (CML-BP). Severe gastrointestinal and renal side-effects were the dose-limiting toxicities occurring in four of five patients treated with CI-973 1200 to 1350 mg/m2 per course. At the MTD of 1000 mg/m2 per course, three of 13 patients treated (23%) had moderate to severe nausea and vomiting, three (23%) had moderate diarrhea and one had moderate mucositis. Among 21 patients treated at > or = 1000 mg/m2 (15 AML, 6 CML-BP) no objective complete or partial responses were observed. Twelve of 18 patients (66%) with evaluable marrows on day 14 showed significant suppression of marrow blasts percentage and marrow leukemic infiltrate percentage. Tests for measurement of DNA adduct formation in leukemic cells in vivo after CI-973 therapy, and in vitro following exposure of leukemic cells to CI-973 were developed. This study defined the MTD of CI-973 to be 1000 mg/m2 by continuous infusion over 5 days every 3 to 4 weeks in patients with refractory or relapsed acute leukemia. Gastrointestinal and renal side-effects were dose-limiting. No objective responses were noted in this heavily resistant population. Correlations between CI-973-induced DNA adduct formation and individual patient response to CI-973 will help to define its role in leukemia subsets.

Acute Disease↗

[Chronic myelocytic leukemia associated with cytomegalovirus induced sialoadenitis after unrelated allogeneic bone marrow transplantation].

A 26-year-old male with chronic myelocytic leukemia was admitted for unrelated allogeneic bone marrow transplantation (BMT). After BMT, he developed swelling of biateral submandibular glands accompanied with pneumonitis possibly due to cytomegalovirus (CMV). Biopsy from the left submandibular gland showed giant cells with nuclear inclusion bodies that were positive for anti-CMV-IE monoclonal antibody, there fore cytomegalic sialoadenitis was diagnosed. The administration of ganciclovir resulted in resolution of the pnumonitis and submandibular gland swelling. Although cytomegalic sialoadenitis is not a life-threating complication in BMT patients, it should be noted that biopsy is very useful for the diagnosis of systemic cytomegalovirus infection.

Adult↗

[Retrospective analysis on 21 patients with follicular lymphoma].

We retrospectively analyzed the clinical data of the 21 patients with follicular lymphoma admitted to our institution from 1977 to 1994. The frequency of follicular lymphoma was 9.1% in the 231 patients with non-Hodgkin's lymphoma. Overall survival rates at 1 year, 3 years, and 5 years were 90.2%, 78.2%, and 52.1%, respectively. The median follow-up of surviving patients and time to treatment failure (TTF) was 43 months and 30 months, respectively. The median time from disease progression to death was 171 days. In univariate analysis, factors associated with poor survival were stage IV (Ann Arbor staging system), anemia (hemoglobin level less than 10g/dl), bone marrow involvement, two or more extranodal sites, and failure in induction of complete remission (CR) in the entire course. Factors associated with short TTF were anemia, bone marrow involvement, and failure in induction of CR. In multivariate analysis, induction of CR affected survival and TTF independently.

Adult↗

[Localized cardiac uptake defect with 123I-MIBG SPECT in a case with pure progressive autonomic failure].

A 60-year-old man with 3 years' history of autonomic nervous system disturbances such as orthostatic hypotension, anhidrosis and atonic bladder is presented. He had an episode of paroxysmal atrial fibrillation as well. He had neither extrapyramidal nor cerebellar signs, and was diagnosed as having pure progressive autonomic failure. His cardiac SPECT with 123I-MIBG showed the loss of uptake at the apex and the inferior wall and the diminished uptake at lateral walls. But 99mTc-tetrofosmin SPECT following an exercise stress showed a normal cardiac uptake. It was suggested that non-cardiac disease-associated postganglionic sympathetic fiber abnormality began from an inferior wall and would extend to a whole heart in this disease. The cardiac 123I-MIBG SPECT is thought to be useful for localizing the denervated area of cardiac sympathetic nervous system.

3-Iodobenzylguanidine↗

[Levels of alpha-elastin and of desmosine as indexes of elastase-induced lung injury in rats].

Two markers of elastin degradation, alpha-elastin and desmosine levels, were measured in sera from rats after single tracheal instillations of porcine pancreatic elastase (PPE). Biochemical and pathophysiological changes in the lung were also studied. Male Wistar rats were divided into three groups. The control group received one intratracheal dose of saline (0.3 ml). The PPE 60 group received one intratracheal dose of 60 U of PPE. The PPE 120 group received one intratracheal dose of 120 of PPE. Blood samples were collected 0, 1, 3, 5, 7, 14, 28, and 56 days after the intervention, and levels of alpha-elastin and desmosine were measured by enzyme-linked immunosorbent assay. At the end of the study (day 56), lung volumes and static pressure-volume curves were measured by body pletysmography. Then the rats were killed and the mean linear intercept was measured as defined by Thurlbeck. The serum alpha-elastin level in the PPE 120 group on day 7 was significantly higher (p < 0.05) than those in other groups. Desmosine values on day 1 in the PPE 60 group and on days 1 and 7 in the PPE 120 group were significantly higher (p < 0.05) than those in the control group. Functional and morphometric analyses revealed that the PPE 120 group had more emphysematous changes than the control group (p < 0.01) and more than the PPE 60 group (p < 0.05). These results suggest that levels of alpha-elastin and of desmosine reflect changes that occur in the early stages of lung injury, and that these changes are related to abnormalities found in rat lungs on day 56.

Animals↗

Successful surgical treatment of cardiac cirrhosis. Tricuspid surgery and plasma exchange.

A patient with cardiac cirrhosis due to severe tricuspid regurgitation associated with a mitral valve lesion successfully underwent mitral and tricuspid valve replacement. Preoperative rest cure with liver supporting therapy for 5 months was used to maximize hepatic and cardiac function. Postoperatively, jaundice developed despite improvements in cardiac function. Plasma exchange was performed nine times over a period of 10 days with the liver function improved. He was discharged with New York Heart Association class I symptoms and normal liver function 2 months following surgery.

Heart Valve Prosthesis↗

[Excellent antiproteinuric effect by LDL apheresis in a case with severe renal dysfunction due to focal segmental glomerulosclerosis].

We report here a 19-year-old man with intractable nephrotic syndrome due to focal glomerulosclerosis (FGS) treated by low-density lipoprotein apheresis (LDL-A). The patient had been receiving several drugs, including steroids, cyclophosphamide, mizoribine and deoxysparguarine, for the past ten years, but the nephrotic syndrome was resistant to these drugs. Although the initial renal biopsy specimen showed minimal change-type lesions, the second biopsy specimen obtained 6 years later revealed typical FGS findings accompanied by lipid deposition (apoB) and macrophage infiltration (CD68) in the involved area. LDL-apheresis was performed ten times per course using a dextran sulfate cellulose column (Liposorba LA-15) as the LDL absorber and polysulfone hollow-fibers (Sulflux) as the plasma separator, processing a total of 3,000 ml of plasma during each apheresis. After treatment the serum levels of LDL and total cholesterol decreased to 50% and 58% of their initial levels, respectively. Immediately after the first course of treatment, the renal dysfunction did not improve, but a decrease in urinary protein was observed (from 43.7 g/day to 8 g/day). Two months later, because urinary protein increased and renal function decreased (Ccr 7 ml/min), a second course of treatment was started. However, his renal dysfunction did not improve and urinary protein did not decrease. In conclusion, in FGS with-progressive renal failure, renal histological findings of positive APO-B, CD68 (macrophage) in sclerotic lesion may be indications of effective LDL-apheresis.

Adult↗

[A comparative study on the efficacies of ritipenem acoxil and cefotiam hexetil in bacterial pneumonia by the double-blind method].

To objectively evaluate the efficacy, safety and usefulness of the newly developed penem oral antibiotic, ritipenem acoxil (RIPM-AC), against bacterial pneumonia, we conducted a multi-center double-blind comparative study using cefotiam hexetil (CTM-HE) as the control drug. Both RIPM-AC and CTM-HE were orally administered at 200 mg t.i.d. for 14 days, in principle. The results were as follows: The total number of patients enrolled in this trial was 208, of which 152 cases (RIPM-AC group: 73, CTM-HE group: 79) were evaluable for clinical efficacy. 1. The clinical efficacy rates (excellent + good) were 91.8% (67/73) in the RIPM-AC group and 94.9% (75/79) in the CMT-HE group. There was no significant difference between the two groups, and the clinical equivalency of RIPM-AC to CTM-HE was demonstrated. 2. In the patients enrolled in the evaluation of clinical efficacy, the eradication rates of the causative organisms were 84.6% (22/26) in the RIPM-AC group and 91.7% (22/24) in the CTM-HE group, with no significant difference between the two groups. 3. Side effects were noted in 9 cases (9.6%) of the RIPM-AC group and 5 cases (4.9%) of the CTM-HE group. Abnormal laboratory test findings were observed in 23 cases (26.7%) of the RIPM-AC group and 15 cases (15.6%) of the CTM-HE group. There was no significant differences between the two groups in the incidence of side effects nor of abnormal laboratory test findings. In the safety evaluation, RIPM-AC was judged to be safe in 64 cases (68.1%) and CTM-HE in 82 cases (80.4%), with no significant difference. 4. The usefulness rates (markedly useful+useful) were 86.5% (64/74) in the RIPM-AC group and 92.5% (74/80) in the CTM-HE group. There was no significant difference between the two groups. Since RIPM-AC showed clinical efficacy similar to those of CTM-HE and posed no particular safety problems, it is expected to be a useful antibiotic for the treatment of bacterial pneumonia.

Adolescent↗

[Surgical-treatment for active infective endocarditis].

The results of surgical treatment of active native infective endocarditis in 24 patients were analyzed. Fifteen of 24 (63%) patients were successfully cured by operation. Three of the 8 patients with severe cardiac failure who underwent emergency operation died of low cardiac output syndrome and bleeding early postoperatively. One of the 6 patients with late death had preoperative cerebral embolism and died of multiple organ failure. Five of them had annular infection. Among 6 patients with annular infection, 3 patients who had Staphylococcus epidermidis and Gram negative bacterium as a causative microorganism had a short duration within 4 weeks from the onset to operation. Two died suddenly in the long-term period after surgery because of prosthetic valve detachment. The second operation were required for other 4 patients because of prosthetic valve endocarditis or perivalvular leakage. Three of them were lost from low cardiac output syndrome. These findings suggested that delayed surgical intervention may be a major causative factor resulting in high surgical mortality. For patients with active native infective endocarditis, an early aggressive operation should be considered prior to congestive heart failure and the destruction of the annulus.

Adult↗