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Biomedical subjects

S Ohta

Publications and source records attributed to S Ohta.

At least 379 records · Page 21Linked to original sources
PubMed1996

Laparoscopic varicocele ligation.

Varicocele, an abnormal dilatation of the pampiniform plexus, frequently contributes to male factor infertility. We performed laparoscopic varicocelectomy in 20 patients with varicoceles and abnormal seminal findings. The spermatic artery was identified and preserved in 13 patients and was clipped along with the veins in 7 patients including 1 patient with bilateral varicocele. The time required for the artery-ligating surgery ranged from 90 to 120 minutes with an average of 113.2 minutes, while the time needed for the artery-preserving technique ranged from 90 to 250 minutes with an average of 158.0 minutes. Some analgesics were administered to 11 patients, while the other 9 patients needed no analgesics. All patients were able to walk within 24 hours of the operation. The mean hospitalization period after the operation was 5.9 days. Sperm concentrations significantly improved postoperatively (p < 0.05). No difference in postoperative improvement of seminal findings was observed between artery-ligating and artery-preserving groups. A slight scrotal emphysema developed during the operation in 1 patient. Abdominal pain was experienced in 1 patient, but subsided within a few days. No serious complications were observed. The laparoscopic technique may replace routine open high ligation as the surgical treatment of choice, especially in patients with bilateral varicocele.

Adult↗
PubMed1996

Monitoring urinary levels of monocyte chemotactic and activating factor reflects disease activity of lupus nephritis.

Monocytes/macrophages (M phi) have been implicated in the pathogenesis of lupus nephritis (LN), but the precise molecular mechanism of recruitment and activation of M phi in LN remains unclear. To clarify the involvement of chemotactic cytokines (chemokines) in those events, we measured levels of monocyte chemotactic and activating factor (MCAF, also termed monocyte chemoattractant protein-1, MCP-1) in urines and sera derived from 42 patients with LN. Both urinary and serum MCAF levels were significantly higher in patients with LN as compared with 22 healthy volunteers (10.3 +/- 3.2 vs. 1.0 +/- 0.1 pg/ml . creatinine, 212.2 +/- 75.8 vs. 66.1 +/- 15.5 pg/ml, respectively, P < 0.05, mean +/- SEM). Histological examination of renal lesions from 41 patients classified 19 as active according to the WHO-defined classes IIIb, IVb and IVc, and 22 as inactive by the WHO-defined classes I, II, IIIc, IVd and V. Urinary MCAF levels in the patients with active lesions were significantly higher than those with inactive lesions (20.3 +/- 6.4 vs. 1.7 +/- 0.3 pg/ml . creatinine, P < 0.01). Moreover, elevated urinary MCAF levels were dramatically decreased during steroid therapy-induced convalescence in 29 patients examined serially (13.9 +/- 4.5 vs. 5.3 +/- 1.7 pg/ml . creatinine, P < 0.001), whereas serum MCAF levels did not change significantly. Endothelial cells, renal epithelial cells and infiltrating mononuclear cells in the tubulointerstitial regions were MCAF-positive in immunohistochemical as well as in situ hybridization analysis. These observations suggest that MCAF is probably involved in the pathogenesis of LN with active lesions, possibly through the recruitment and activation of M phi, and that measurement of urinary MCAF levels may be a useful clinical tool for monitoring the disease activity of LN.

Adolescent↗
PubMed1996

High efficiency transformation of maize (Zea mays L.) mediated by Agrobacterium tumefaciens.

Transformants of maize inbred A188 were efficiently produced from immature embryos cocultivated with Agrobacterium tumefaciens that carried "super-binary" vectors. Frequencies of transformation (independent transgenic plants/embryos) were between 5% and 30%. Almost all transformants were normal in morphology, and more than 70% were fertile. Stable integration, expression, and inheritance of the transgenes were confirmed by molecular and genetic analysis. Between one and three copies of the transgenes were integrated with little rearrangement, and the boundaries of T-DNA were similar to those in transgenic dicotyledons and rice. F1 hybrids between A188 and five other inbreds were transformed at low frequencies.

Agrobacterium tumefaciens↗
PubMed1996

Increased expression of carnitine palmitoyltransferase I gene is repressed by administering L-carnitine in the hearts of carnitine-deficient juvenile visceral steatosis mice.

The juvenile visceral steatosis (JVS) mouse is a novel mutant animal for studying systemic carnitine deficiency. The importance of the model has been pointed out in carnitine-deficient cardiac hypertrophy, since cardiomyopathy has been often improved after oral carnitine therapy in human systemic carnitine deficiency. To understand the effects of carnitine deficiency on gene expression in the heart, we tried to find the genes regulated by carnitine by means of a modified differential display procedure. Carnitine palmitoyltransferase I (CPT I) was one of the isolated genes. The level of CPT I gene expression in the ventricles of the JVS mice was at least three- to sixfold that of normal mice as judged by reverse transcription-polymerase chain reaction (RT-PCR). When the JVS mice were treated with carnitine, CPT I gene expression was repressed to the level of normal mice. Therefore, the increased expression of the CPT I gene was associated with carnitine deficiency.

Amino Acid Sequence↗
PubMed1996

Expression of the apoptosis-mediator Fas is enhanced by dysfunctional mitochondria.

We applied an antibody against an apoptosis mediator, Fas/APO-1/CD95, to HeLa-derived cells that completely lack mitochondrial DNA (mtDNA) or have mutant mtDNAs. The anti-Fas antibody killed the cells completely lacking mtDNA (EB8), at concentrations as low as 1 ng/ml, but not control cells harboring wild-type mtDNA (Ft2-11). TUNEL (terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end-labeling) and analysis of fragmented DNA indicated that the cell death of EB8 was due to apoptosis. The antibody was cytotoxic to other two cell lines harboring mutant mtDNA with a point mutation or a large-scale deletion. RT-PCR (reverse transcriptase-polymerase chain reaction) showed that the mRNA content of the Fas gene was 2 to 19-fold higher in the cells with deficient mtDNA than in the control cells. In addition, the expressed Fas protein was detected by immunohistochemical staining in the cells without mtDNA but not in the control cells. Incubating the cells containing wild-type mtDNA with the respiratory inhibitors rotenone and antimycin A enhanced the content of mRNA of the Fas gene 2 to 4-fold and sensitized cells to the antibody. Thus, defects in mitochondria caused apoptotic cell death by anti-Fas antibody and enhanced Fas gene expression.

Antimycin A↗
PubMed1996

Cerebral [15O]water clearance in humans determined by PET: I. Theory and normal values.

When used to measure blood flow in the brain, water leaves a residue in the vascular bed that influences the estimation of blood flow by current methods. To assess the magnitude of this influence, we developed a two-compartment model of blood flow with separate parameters for transport and vascular distribution of brain water. Maps of the water clearance, K1 into brain tissue, separated from the circulation by a measurably resistant blood-brain barrier (BBB), were generated by time-weighted integration. Depending on the validity of the assumptions underlying the two-compartment model presented here, the maps revealed a significant overestimation of the clearance of water when the vascular residue was ignored. Maps of Vo, the estimate of the apparent vascular distribution volume of tracer H2(15)O, clearly revealed major cerebral arteries. Thus, we claim that the accumulation of radioactive water in brain tissue also reflects the volume of the arterial vascular bed of the brain.

Body Water↗
PubMed1996

Calcium movement in ischemia-tolerant hippocampal CA1 neurons after transient forebrain ischemia in gerbils.

Hippocampal CA1 neurons exposed to a nonlethal period (2 min) of ischemia, acquired tolerance to a subsequent lethal 5-min period of ischemia, which usually causes delayed-type neuronal death. Intracellular Ca2+ movements before and after the 5 min of forebrain ischemia were evaluated in gerbil hippocampal CA1 pyramidal neurons, had acquired tolerance in comparison with nonischemia-tolerant CA1 neurons. Evaluation was performed by observing the ultrastructural intracellular Ca2+ distribution and the Ca2+ adenosine triphosphatase (Ca(2+)-ATPase) activity using electron microscopic cytochemistry. In comparison with nonischemia-tolerant CA1 neurons, mitochondria of ischemia-tolerant CA1 neurons sequestered more Ca2+ from the cytosomal fraction 15 min after the 5-min period of ischemia, and Ca2+ deposits in these mitochondria were rapidly decreased. Plasma membrane Ca(2+)-ATPase activities were already significantly elevated before the 5 min of ischemia, and remained at a higher level subsequently compared to nonischemia-tolerant CA1 neurons. Changes in the mitochondrial Ca2+ distribution and Ca(2+)-ATPase activities in ischemia-tolerant CA1 neurons after the 5-min period of ischemia showed a strong resemblance to those in CA3 neurons, which originally possess resistance to such periods of ischemia. These findings suggest that enhanced or maintained activities of mitochondrial Ca2+ sequenstration and plasma membrane Ca(2+)-ATPase reduced Ca2+ toxicity following 5-min ischemia in terms of time, resulting in escape from delayed neuronal death.

Animals↗
PubMed1996

Protein synthesis and immunoreactivities of contraction-related proteins in smooth muscle cells of canine basilar artery after experimental subarachnoid hemorrhage.

We examined time-dependent changes in protein synthesis and in the immunoreactivities of representative contraction-related structural proteins in smooth muscle cells of canine basilar arteries after experimental subarachnoid hemorrhage (SAH). Protein synthesis was assessed by the percentage of polyribosome-forming ribosomes to total ribosomes (aggregation rate), a morphological index of the activity of protein synthesis. The aggregation rates in prostaglandin F2 alpha-(PGF 2 alpha) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced contracted basilar arteries were 70.0 +/- 7.0% and 71.4 +/- 8.7%, respectively, quite similar to the value in normal basilar artery (73.0 +/- 8.0%). In the single-SAH group with little delayed histological changes in the basilar arteries, the aggregation rate was significantly decreased to 30.5 +/- 6.4% by 24 h after the SAH, and recovered to 52.3 +/- 9.0% and 70.2 +/- 7.6% at 7 and 14 days postSAH, respectively, when the vasospasm was moderately and completely ameliorated. In contrast, in the double-SAH group in which the basilar arteries developed delayed smooth muscle cell death and long-lasting arterial contraction, a significant decrease in the aggregation rate (25.0 +/- 5.0% on day 4) persisted for 14 days. The in vitro incorporation of [3H]-leucine in the basilar arterial cells was also significantly suppressed 4 and 7 days after the initial SAH (1.2 +/- 0.4 and 1.4 +/- 0.3 x 10(3) dpm/mg protein) in the double-SAH group, as opposed to no significant decrease in the basilar artery at 7 days postSAH in the single-SAH group (1.9 +/- 0.6 x 10(3) dpm/mg protein). The immunoreactivity of alpha-smooth muscle actin, a contractile protein, demonstrated by immunohistochemistry and immunoblots, was not altered for up to 14 days even in the double-SAH group, but that of calponin and of h-caldesmon, contraction-inhibiting proteins, was markedly reduced 4-14 days after the initial SAH. Persistent impairment of protein synthesis and relative reduction of immunoreactivities of the contraction-inhibiting proteins were observed in arteries with severe vasospasm and loss of smooth muscle cells, as noted in the double-SAH subjects. These abnormalities may cooperate to cause cerebral arterial narrowing accompanied by degeneration of smooth muscle cells after SAH.

Actins↗
PubMed1996

Successful percutaneous transluminal angioplasty for basilar artery stenosis: technical case report.

OBJECTIVE: We report our experience with low-pressure submaximal percutaneous transluminal angioplasty (PTA) for basilar artery stenosis of > 90%. This treatment resulted in a favorable clinical course and satisfactory improvement of posterior cerebral circulation. CLINICAL PRESENTATION: This technique was applied to two patients with repeated basilar arterial ischemic symptoms that were resistant to medical treatment. INTERVENTION: Low-pressure submaximal PTA was performed with use of a smaller balloon (2.0-mm diameter) and lower inflation pressure (< or = 303,975 Pa) than previously reported. RESULTS: Despite basilar arteries with 50 and 60% residual stenosis, the clinical symptoms and hemodynamics in the basilar arterial territory as assessed using single photon emission tomography were markedly improved after PTA. Follow-up angiographic evaluation demonstrated the absence of restenosis, and improved cerebral blood flow was maintained. Neither patient has developed any new neurological deficits 10 and 13 months after the PTA, respectively. CONCLUSION: Submaximal PTA may have reduced the high risk associated with this procedure, and cerebral blood flow measurement may be a useful tool to assess whether this technique will produce adequate results.

Aged↗
PubMed1996

Malignant mesenchymoma arising from the prostate in Gardner's syndrome.

The first case of a primary malignant mesenchymoma arising from the prostate in Gardner's syndrome is reported. The neoplasm occurred in a 40-year-old man with a chief complaint of urinary retention. Biopsy findings were primary malignant mesenchymoma. Total cystectomy and lymphadenectomy were performed, but the patient died due to multiple metastases within 6 months. He had undergone a colectomy for polyposis coli 17 years earlier and had mandibular osteomas. This was the first case of malignant mesenchymoma arising from the prostate in Gardner's syndrome.

Abdominal Neoplasms↗
PubMed1996

Comparative fungicidal activity of a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N,N-dimethylammonium butyl phosphate and commonly used disinfectants.

We synthesized a new quaternary ammonium salt, N-alkyl-N-2-hydroxyethyl-N, N-dimethylammonium butyl phosphate (ABP) that does not precipitate in the presence of anionic surfactants by incorporating a paired butyl phosphate anion into cationic surfactants. ABP showed much greater bactericidal activities and antirusting effects than benzalkonium chloride (BAC). In this study, the fungicidal effects of ABP were evaluated in comparison with common disinfectants [BAC, chlorhexidine digluconate (CHX) and alkyldiaminoethylglycine hydrochloride (ADE)]. Fungicidal effects were evaluated in 10 strains of 6 fungal species, namely, 3 Candida albicans, 2 Candida tropicalis, 1 Candida parapsilosis, 1 Aspergillus niger, 2 Aspergillus terreus, and 1 Trichophyton rubrum. ABP and BAC showed the same effects on 2 C. tropicalis and C. parapsilosis, and similar effects on 3 C. albicans, with slight differences among the strains. ABP showed quick fungicidal effects against A. niger and 2 A. terreus of molds in 30 min at 0.1% and in 15 min at 0.2 and 0.4%, but BAC showed slow effects against A. niger at 1 h and 2 A. terreus at 30 min at 0.2 and 0.4%, respectively. There is one factor, which may have caused this difference: the former had a butyl phosphate anion and the latter had a chloride anion as a counter ion. BAC, CHX and ADE needed 24h to cause notable effects on A. niger at 0.1% and 1 h at 0.2%. The new synthetic anti-rust ABP is considered to have sufficient fungicidal effects that are comparable to those of BAC, CHX and ADE.

Disinfectants↗
PubMed1996

Biochemical characterization of a Pseudomonas fluorescens strain isolated from a benzalkonium chloride solution.

A bacterium isolated as the contaminant of a batch of commercial benzalkonium chloride (BAC) solution (10% (w/v)) stored in a loosely capped bottle in the Department of Pharmacy Shinshu University Hospital was identified as Pseudomonas fluorescens belonging to biotype G of Stanier, et al. The strain was highly resistant to BAC, and the lowest concentration of BAC that inhibited visible growth of the strain as measured on nutrient agar plates was > or = 5000 micrograms/ml. BAC is a typical quaternary ammonium detergent. Thus we examined the tolerable growth concentration of various strains on surfactants. We were able to confirm growth of P. fluorescens of BAC resistance strain (PFRB) in 5% concentration, but the other strains were not able to grow in 0.1% concentration. We investigated the relationship between biotype and resistance to BAC. PFRB and three clinical isolated strains were found to be the same biotype G. However, no apparent correlation was found between the same biotypes and minimum inhibitory concentration (MIC) of disinfectant or growth permissible concentration on surfactants. The strain was unable to decompose BAC, as no growth occurred in the minimum medium containing BAC as the sole source of carbon, nitrogen or both. Our finding caused us to realize that P. fluorescens might also be a contaminant of disinfectants, as we have seen in Pseudomonas cepacia.

Benzalkonium Compounds↗
PubMed1996

[Changes in the production of reactive oxygen species from neutrophils following a 100-km marathon].

Recently, the numbers of city marathon runners and joggers have increased. They believe that exercise can enhance their fitness level and health maintenance. However, many researchers have suggested that exhausting exercise may increase the risk of infection and free radical generation. In this study, eight male and ten female city marathon runners who participated in the Akita Nairiku Resort Cup 100-km Challenge Marathon Race were studied using luminol-dependent chemiluminescence (LDCL) to examine the ability of their neutrophils to produce reactive oxygen species. Furthermore, serum opsonic activity using LDCL, serum concentrations of the third and fourth components of the complement (C3, C4), the total number of leukocytes, and proportion of leukocytes were also determined. Evaluation of LDCL was undertaken using the maximum light emission (peak height) and the time to reach the maximum light emission (peak time) in the response curve of LDCL. Following the race, the peak time was prolonged by 11% in males and 15% in females, and the peak height increased by 68% in males and 48% in females. These results suggest that exhausting exercise stimulates neutrophils to produce reactive oxygen species. The total number of leukocytes increased about twofold, whereas the number of neutrophils increased about threefold after the race as compared to before. The rate of the increase in leukocytes was closely associated with that of neutrophils (r = 0.96, P < 0.01). Therefore, the leukocytosis observed in this study was dependent on neutrophilia. Serum opsonic activity and serum concentrations of C3 and C4 were not changed following the race. The increase in the ability of neutrophils to produce reactive oxygen species and neutrophilia after the race, suggests that a large quantity of reactive oxygen species may be produced in vivo following exhausting exercise.

Adult↗