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Biomedical subjects

M Yoshimura

Publications and source records attributed to M Yoshimura.

At least 541 records · Page 30Linked to original sources
PubMed1991

[Influences of pregnancy on the natural course of chronic glomerulonephritis with impaired renal function].

In an attempt to clarify the influence of pregnancy on the natural course of the chronic glomerulonephritis with impaired renal function (glomerular filtration rate: GFR less than or equal to 70 ml/min), the courses of 14 pregnancies occurring in 10 patients (seven with IgA nephropathy, one with membranoproliferative glomerulonephritis, one with membranous nephropathy and one with hereditary nephropathy) were studied. In 8 patients GFR measured before pregnancies ranged from 46 to 70 ml/min and in the other two creatinine clearance estimated in the first trimester of pregnancies was 62 and 49 ml/min, respectively. The pregnancies resulted in 10 live births, one spontaneous abortion, one artificial abortion and 2 neonatal deaths. In 2 out of 10 live births fetal weight was less than 2500 g. In 3 of 11 pregnancies there was neither increase in urinary protein nor elevation of blood pressure during pregnancies, while seven (64%) had increased proteinuria during the third trimester, and 4 of them were also complicated with hypertension. In 6 of 10 patients, there was no decrease in GFR during pregnancies. In three patients GFR was decreased from 70 to 36 ml/min, 70 to 58 ml/min and 62 to 48 ml/min, respectively. However, these reductions were considered to go with the natural course of respective patients because the reduction slopes were almost the same or rather mild in comparison with those estimated before or after pregnancies. The other patient also had a transient increase in serum creatinine level during two pregnancies, but the reciprocals of serum creatinine concentration before and after the pregnanciesdeclined linearly with time. These data suggest that pregnancy might have little influence on the natural course of the chronic glomerulonephritis even if complicated with renal functional impairment defined as GFR of 70 ml/min or less.

Adolescent↗
PubMed1991

[Scintigraphic quantification of myocardial necrosis using "hot spot" imaging agents in acute myocardial infarction].

Both technetium-99m pyrophosphate/thallium-201 dual nuclide SPECT and indium-111 antimyosin antibody/thallium-201 dual nuclide SPECT were performed in identical 11 patients with acute myocardial infarction. Infarct size was calculated by both hot spot imaging agents on dual nuclide SPECT. Antimyosin accurately accumulated in the infarcted area in all 11 patients on SPECT images corresponding with the electrocardiography, but pyrophosphate accumulated at the site of infarct in 10 of 11 patients. The mean volume obtained from pyrophosphate was 32.5 ml and that from antimyosin was 21.9 ml. The relationship between infarct volume calculated by pyrophosphate and that by antimyosin was linear and correlated well (r = 0.98, p less than 0.001). However the volume of infarction determined with pyrophosphate exceeded that with antimyosin SPECT by 1.64 (p less than 0.001). The reason for this difference is not yet known, but may relate to pyrophosphate uptake in border zones that may or may not be irreversibly injured.

Adult↗
PubMed1991

[Long-term prognosis after reperfusion therapy with emergency coronary angioplasty for acute myocardial infarction].

The influence of emergency coronary angioplasty (PTCA) for acute myocardial infarction on long-term survival was investigated. We followed 141 patients treated with emergency PTCA and 202 patients treated with thrombolytic therapy alone for a median of 1,157 days and a median of 2,133 days, respectively. All were initially completely occluded at the infarct-related coronary artery (IRCA). Actuarial survival curves were compared and independent predictors of late cardiac death were determined using Cox's proportional hazard model between overall patients and patients whose IRCA was at the proximal site of the left anterior descending artery (LAD). 1. Actuarial survival curves were similar in 2 groups. 2. Independent predictors of late cardiac death in overall follow-up patients were advanced age over 65 years (p < 0.03), a history of previous myocardial infarction (p < 0.03), severer stage of the Killip class on admission (p < 0.003), and the infarct-related proximal LAD (p < 0.01). 3. Among patients with the proximal LAD, the actuarial survival curve was better in those treated with emergency PTCA than in those treated with thrombolytic therapy alone (p < 0.01). 4. Among patients with the proximal LAD, independent predictors of late cardiac death were advanced age over 65 years (p < 0.03), treatment with thrombolytic therapy alone (p < 0.03), left ventricular ejection fraction < or = 40% (p < 0.06), and occluded IRCA on predischarge angiograms (p < 0.08). Among patients with the occluded proximal LAD, those treated with emergency PTCA showed better long-term survival rate than did patients with thrombolytic therapy alone, and this may be explained by higher successful reperfusion rates in the former than in the latter.

Aged↗
PubMed1991

Block of Na+ channels by imipramine in guinea-pig cardiac ventricular cells.

The effects of imipramine on the Na+ current of guinea-pig ventricular myocytes were examined by the whole-cell clamp method. Imipramine inhibited the Na+ current with a dissociation constant value of 25 microM at a -130 mV holding potential. At 1 microM, imipramine caused a negative shift of the channel availability curve by 4.0 +/- 1.03 mV with its steepness unaffected. The inactivation time constants were not changed by 30 microM imipramine. Paired pulse experiments revealed that imipramine binds to the inactivated Na+ channels with time constants of 3.7 +/- 0.27 sec at -65 mV and 2.4 +/- 0.58 sec at -20 mV, and that it dissociates from the channels with time constants of 5.9 +/- 1.05 sec at -90 mV and 2.0 +/- 0.87 sec at -130 mV. From these paired pulse experiments, the dissociation constant for the interactions between imipramine and inactivated channels was calculated to be 0.67 microM, a value within its therapeutic plasma concentration. These slow interactions of imipramine with inactivated Na+ channels resulted in a slow onset of the frequency-dependent extrablock in the effects of imipramine on the Na+ current. Consequently, the imipramine-induced extrablock sufficient to terminate re-entrant tachyarrhythmias would not develop shortly after their initiation. Short depolarizations of 1- to 3-msec duration sustained appreciable extra blockage when a high concentration of 10 microM imipramine was used, or they were repeatedly applied at a high frequency. However, access of imipramine to the open channels seems to play a minor role in the drug-channel interactions.

Action Potentials↗
PubMed1991

[Development of slow releasing anticancer drug based with absorbable biomaterial chitin].

To have a comparatively more slowly releasing anticancer drug with effectiveness, Plachitin was prepared by chemical combination of CDDP and chitin (poly-N-acetyl-D-glucosamine). Chitin is absorbed by the living body over several months. To investigate the slow releasing property, it was implanted in thigh muscle of mice and rabbit. Pt level in different organs and in urine was measured at regular intervals. Pt level in implanted muscles was higher in comparison to low serum level in mice. It was released slowly over 1 to 2 months in mice, whereas in rabbit it took about three weeks. Pt releasing period of the Plachitin was different according to the adopted method of implantation. Anticancer effect of Plachitin was investigated by injecting 180 sarcoma cells in mouse peritoneal cavity and subsequent implantation of Plachitin. In control groups chitin was used instead of Plachitin. The survival rate of mice in the Plachitin group after 14 days was higher than in the chitin group, and the anticancer effect of the Plachitin was confirmed.

Absorption↗
PubMed1991

[FDP levels in the cerebrospinal fluid are elevated in patients with meningitis].

Since the level of fibrinogen degradation products (FDP) are elevated with severity of inflammation, we assumed that FDP in the cerebrospinal fluid (CSF) could be a marker of meningitis. We, therefore, measured FDP in the CSF of 6 patients with bacterial meningitis and 6 aseptic meningitis. The range of FDP levels in the CSF in patients without meningitis was 0.21 +/- 0.01 microgram/ml. While, the level of FDP in patients with aseptic meningitis (0.43 +/- 0.10 microgram/ml) and in bacterial meningitis (1.78 +/- 0.42 micrograms/ml) was significantly elevated (p less than 0.05). The value was significantly (p less than 0.01) higher in the group of septic meningitis than in aseptic meningitis. In one patient with septic meningitis, we could measure FDP in the CSF several times during the course of the disease, in which the level of FDP got into the high range earlier than the changes in levels of protein, glucose and cell counts in the CSF. FDP in the CSF well correlated to the clinical course of the meningitis. Eventually, we found that FDP in the CSF was definitely elevated in patients with bacterial meningitis, whereas it was slightly elevated in patients with aseptic meningitis. The measurement of FDP in the CSF, therefore, is concluded to be useful for the differential diagnosis of meningitis, and to assess the clinical course of meningitis.

Adolescent↗
PubMed1991

[A case of amyotrophic lateral sclerosis with disturbance of vertical ocular movement responding to thyrotropin releasing hormone (TRH)].

A 64-year-old woman who had amyotrophic lateral sclerosis (ALS) with disturbance of vertical ocular movement was presented. She was admitted to our hospital with progressive dysphagia, dysarythria and weakness of the extremities. Neurological examinations revealed disturbance of vertical ocular movement with normal doll's eye phenomenon (supranuclear origin), bulbar palsy, muscle weakness of the extremities, extensor plantar signs, and fasciculations of the costal and interosseal muscles. EMG studies showed denervation potentials, and muscle biopsy demonstrated group atrophy, fiber type grouping and small angular fibers. TRH injections resulted in improvement of disturbance of vertical ocular movement, but no effect was seen on the weakness of the limb. There was about 20 Japanese cases with disturbance of ocular movement in ALS, but it was rare to see ocular movement disorder from the early stage of ALS. The pathophysiology of ocular movement disorder in ALS has been thought to be due to supranuclear origin, i.e., the disturbance in the pathway from the frontal cortex to the mesencephalon. In this case, TRH might effect at some point of the frontomesencephalic pathway.

Amyotrophic Lateral Sclerosis↗
PubMed1991

[Differentiation of intestinal candidial colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose amphotericin B].

The measurement of D-arabinitol in serum has been reported to be useful for the diagnosis of invasive candidiasis. However, excessive proliferation of Candida species in intestinal tract often leads false positive result of serum D-arabinitol. Based on the evidence that amphotericin B (AMPH) is scarcely absorbed from intestinal tract and inhibits the proliferation of Candida species only in intestinal tract, we have developed a simple differentiation method of intestinal candida colonization from invasive candidiasis by measuring serum level of D-arabinitol in combination with oral administration of low dose AMPH. AMPH, 600 mg/day for 2 days was orally administered to five patients with hematological malignancies who showed more than 1.7 mumol/mg of D-arabinitol/creatinine ratio (D/C ratio) in serum without any evidence of invasive candidiasis. D/C ratios were markedly decreased and normalized after the oral administration of low dose AMPH. While, in a patient with invasive candidiasis in whom Candida species was detected by blood cultures, D/C ratio remained unchanged in spite of oral administration of AMPH. These observations suggest that this method is a simple and reliable diagnostic method to distinguish intestinal candida colonization from true invasive candidiasis.

Administration, Oral↗
PubMed1991

[Metastases to the mediastinal lymph nodes in a series of two-hundred-consecutive operations for primary lung cancer].

We examined the characteristics of lymph nodes metastases to the mediastinum on cases of two-hundred-consecutive operations for primary lung cancer from October of 1987 to May of 1990, comparing the intraoperative macroscopic diagnosis of lymph nodes to the histologic reports. The purpose of this study is to know how important the mediastinal dissection is and how many cases resulting in vain are hidden behind it. Thirty three cases were excluded because of limited operation or other reasons. Remaining a hundred sixty seven cases were divided on the basis of lymph node metastasis into following 5 groups. Forty three cases (26%), of which N2 disease was correctly diagnosed macroscopically, true positive for N2, were classified into group A. Sixteen cases (10%), group B, in which we failed to detect N2 positive from dissected specimens during operation, was considered to be false negative for N2, thirty one cases of N1 disease (18%), were classified into group C and thirteen cases of N0 disease (8%) into group D with false positive of lymph node prediction for metastasis. Sixty four cases of N0 disease (40%) were classified into group E, true negative for N0 prediction, which were correctly detected by macroscopic appearance of lymph nodes. Nine cases had only mediastinal lymph nodes metastases without hilar and lobar lymph node. Almost of them with this skip phenomenon occurred in the patients with adenocarcinoma in the upper lobe. It could be concluded that we dissected the mediastinal lymph nodes in this series, salvaging one N2 disease of ten cases and wasting our efforts four cases of those cases, in vain.

Adenocarcinoma↗
PubMed1990

Induction of sexual agglutinability by unsaturated fatty acids in Saccharomyces cerevisiae.

Agglutinins in S. cerevisiae are necessary for mating, for recognition between cells of opposite mating type. The mode of agglutinin synthesis is altered by the growth temperature and by the carbon source, from constitutive to inducible synthesis and vice versa. Some of the unsaturated fatty acids tested induced synthesis of agglutinins in cells grown at an elevated temperature, even in the absence of the pheromone. However, synthesis of agglutinins in glycerol-grown cells, that are inducible by the pheromone, was not induced by linolenic acid. Hence, the change in the mechanism of regulation of agglutinability produced by differences in temperature probably differs from that produced by differences in carbon source.

Agglutination↗
PubMed1990

Digital replantation in children: a long-term follow-up study.

This paper reports a series of 14 cases of digital replantation in children who had had a total of 17 digits traumatically amputated. All but two digits survived, for an overall success rate of 88%. The length of follow-up was between 3 and 14 years (average 8 years). Sensory recovery of all digits was satisfactory. The mean growth rate of replanted digits relative to contralateral digits was 86%. Twelve cases had an excellent result, and one case had a good result. Digital replantation in children is recommended when feasible.

Amputation, Traumatic↗
PubMed1990

Mutant of the glutamine transfer RNA gene as UGA suppressor in Escherichia coli.

A UGA suppressor derived from a glutamine tRNA gene of Escherichia coli K12 was isolated and characterized. Phages carrying the suppressor su+2UGA could be obtained only from a hybrid transducing phage, h80cI857psu+2oc, but not from the original transducing phage lambda cI857psu+2oc. By DNA sequence analysis, it was found that the su+2 UGA suppressor obtained has two mutations; one is in the anticodon (TTA----TCA), as expected, and the other (C----T) is at the 7th position from the 3' end of tRNA(2Gln). The significance of these mutations and the lethal effect on phage lambda of the increased amounts of UGA suppressor tRNAs are discussed.

Bacteriophages↗
PubMed1990

Senile dementia of Alzheimer type characterized by laminar neuronal loss exclusively in the hippocampus, parahippocampus and medial occipitotemporal cortex.

Seven cases of senile dementia of Alzheimer type (SDAT) with unusual clinico-pathological findings are reported. The patients showed neuronal loss in laminar pattern, with gliosis exclusively confined to the CA1 of the hippocampus, the area of the hippocampal gyrus (entorhinal cortex) and medial occipitotemporal cortex. This change was more pronounced in the oral region. The subcortical white matter showed more pronounced fibrillary gliosis than loss of myelin. Both Alzheimer's neurofibrillary tangles and senile plaques were less marked than those usually seen in SDAT. The mental disturbance started after the age of 65 in all patients. The main clinical feature was marked character change in addition to disturbance of cognitive function. Cranial computed tomography showed marked dilatation of the oral portion of the inferior horn of the lateral ventricle in the early stage. It was apparent that although the cases in this group could be incorporated within in the spectrum of SDAT, they could also be considered to represent a variant of SDAT. This group could contribute to an understanding of the clinico-pathological spectrum of SDAT as well as indicating ways of managing such patients.

Aged↗
PubMed1990

Efficacy and safety of carvedilol in renal hypertension. A multicenter open trial.

Carvedilol, a novel beta-blocker with a vasodilating action, was given either alone (monotherapy) or with diuretics (combination therapy) to 42 patients with renal hypertension. The hypotensive effect, safety, and optimal dose were investigated. In all, 23 untreated patients (16 men and 7 women; average age, 56.4 +/- 2.5 years) made up the monotherapy group and 19 diuretic-treated patients (11 men and 8 women; average age, 56.4 +/- 2.5 years) comprised the combined therapy group. All subjects had an initial blood pressure (BP) of greater than 160/95 mmHg and were started on 5 mg/day oral carvedilol. The dose was gradually increased to a maximum of 20 mg/day, or until either the BP was reduced to less than 149/89 mmHg or the reduction in mean BP was greater than 13 mmHg compared with baseline levels. The total study period was 8 weeks. With monotherapy, the BP and heart rate decreased significantly from 167/102 to 150/94 mmHg and from 81 to 74 beats/min, respectively. With combined therapy, the BP and heart rate fell significantly from 176/103 to 142/85 mmHg and from 81 to 70 beats/min, respectively. Responders were defined as subjects with a BP of less than or equal to 149/89 mmHg or those showing a fall of greater than or equal to 13 mmHg in mean BP. Responders accounted for 52.2% of the monotherapy group and 73.6% of the combination therapy group. Orthostatic hypotension was not seen in either group. Serum creatinine and blood urea nitrogen (BUN) levels were not altered by administration of carvedilol. Dizziness was noted by 1 of the 23 subjects in the monotherapy group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1990

Primary culture of normal rat mammary epithelial cells within a basement membrane matrix. II. Functional differentiation under serum-free conditions.

A serum-free primary culture system is described which allows normal rat mammary epithelial cells (RMECs) embedded within a reconstituted basement membrane to undergo extensive growth and functional differentiation as detected by synthesis and secretion of the milk products casein and lipid. RMECs isolated from mammary glands of immature virgin rats were seeded within an extracellular matrix preparation derived from the Engelbreth-Holm-Swarm sarcoma and cultured in a serum-free medium consisting of Dulbecco's modified Eagle's medium-F12 containing insulin, prolactin, progesterone, hydrocortisone, epidermal growth factor, bovine serum albumin, transferrin, and ascorbic acid. Casein synthesis and secretion were documented at the electron microscopic level as well as by an enzyme-linked immunosorbent assay (ELISA) assay using a polyclonal antibody against total rat caseins. Numerous secretory vesicles with casein micelles were noted near the apical surface of the RMECs, and secreted casein was observed in the lumen. These ultrastructural data were confirmed by the ELISA assay which showed that microgram amounts of casein per well were synthesized by the RMECs and that the amount of casein increased with time in culture. Using immunoblot analysis it was demonstrated that the full complement of casein proteins was synthesized. In addition to casein protein, beta-casein mRNA levels were shown to increase with time. Synthesized lipid was detected at both the light and electron microscopic levels. Phase contrast photomicrographs demonstrated extensive intracellular lipid accumulation within the ductal and lobuloalveolarlike colonies, and at the electron micrograph level, lipid droplets were predominantly localized near the apical surface of the RMECs. The lipid nature of these droplets was verified by oil red O staining. Results from this study demonstrate that RMECs from immature virgin rats proliferate extensively and rapidly develop the capacity to synthesize and secrete casein and lipid when grown within a reconstituted basement membrane under defined serum-free conditions. This unique system should thus serve as an excellent model in which the regulation of mammary development and gene expression can be investigated.

Animals↗
PubMed1990

Transfection of beta-casein chimeric gene and hormonal induction of its expression in primary murine mammary epithelial cells.

To study the regulatory sequence elements responsible for casein gene expression, we constructed a chimeric gene containing 5.3 kilobases (kb) of the 5'-flanking sequence and 1.6 kb of the 3'-flanking sequence of the mouse beta-casein gene fused to the bacterial chloramphenicol acetyl-transferase (CAT) gene. The chimeric gene was transfected by the calcium phosphate-precipitation procedure into primary mouse mammary epithelial cells prepared from pregnant mice. The transfection procedure had negligible effect on expression of the endogenous beta-casein gene. Expression of the beta-casein-CAT chimeric gene required the synergistic actions of insulin, hydrocortisone, and prolactin. Expression of the chimeric gene also depended on the appropriate substratum because the degree of hormonal induction of the chimeric gene was much higher in cells cultured on a reconstituted basement membrane (Matrigel) than in cells cultured on either type I collagen gel or plastic. On the other hand, the expression of a simian virus 40-CAT chimeric gene in which the CAT gene was driven by the early promoter of the virus was not influenced by the hormonal milieu and occurred at the highest level in cells cultured on plastic. Additional transfection experiments with a series of beta-casein-CAT constructs suggested the existence of regulatory elements responsible for hormonal induction and negative regulatory elements.

Animals↗
PubMed1990

A new method for repairing skin defects of the lower leg under unsatisfactory conditions: utilization of peroneal island flap from the opposite sound leg.

As a new procedure for the repair of tissue defects in the lower leg under unsatisfactory conditions, we have devised a surgical procedure for peroneal island flap transfer from the opposite sound leg. This report presents three patients treated by cross-leg island flaps with reversed blood flow. This procedure can be applied for reconstruction of the leg with severe circulatory disturbance caused by arterial damage due to trauma and arterial disease such as Buerger's disease. Furthermore, joint exercise is possible because the pedicle is long and no rigid immobilization is required.

Humans↗