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Biomedical subjects

S Nishimura

Publications and source records attributed to S Nishimura.

At least 595 records · Page 33Linked to original sources
PubMed1989

Synthesis and biological activity of 7 alpha-hydroxyethyl-1-oxacephem derivatives.

A series of 7 alpha-hydroxyethyl-1-oxacephems (1) was synthesized. The main focus of this study was to investigate biological activity relationships between 1-oxacephems (1) and the corresponding cephems (2). Replacement of the sulfur atom of 2 by the oxygen atom caused an enhancement of antibacterial activity, although the antibacterial activity of 1 was not high enough. Additionally 1 showed beta-lactamase inhibitory activity, especially against cephalosporinase. However, the potency was lower than that of 2.

Anti-Bacterial Agents↗
PubMed1989

Embryonal tumors from transgenic mouse zygotes carrying human activated c-Ha-ras genes.

To investigate the function of activated oncogenes we attempted to create transgenic mice carrying activated human c-Ha-ras genes which have their own promoters. However, we never obtained any transgenic pups which developed to term, because all transgenic embryos were malformed, became developmentally arrested conceptuses or developed embryonic tumors during ontogenesis. The mRNA expression of the transgenes was detected in two tumors obtained after introduction of the DNA fragment containing the activated human c-Ha-ras gene for p21 with valine at the 12th codon or with leucine at the 61st codon. Histological analysis indicated that each tumor consisted of at least three types of cells: two originating from different germ layers (the endoderm in one case and the mesoderm in the other) and the third from extra embryonic ectoderm. It was suggested that the activated human c-Ha-ras gene has a critical effect on the development of tumors in normal embryos as well as in transformation of NIH3T3 cells.

Animals↗
PubMed1989

Effect of beraprost sodium on peripheral circulatory disturbances induced by various stimuli.

Effects of beraprost sodium (sodium(+/-)-(1R*,2R*,3aS*,8bS*)-2,3,3a,8b-tetrahydro-2-hydr oxy-1- [(E)-(3S*)-3-hydroxy-4-methyl-octen-6-ynyl]-1H-cyclopenta[b] benzofuran- 5-butyrate, TRK-100), a stable prostacyclin analogue, on the peripheral circulatory disturbances induced by various vasoconstrictive stimuli were studied. Orally administered beraprost sodium (10, 30 micrograms/kg) caused increase in skin blood flow in anesthetized rats and rise in skin temperature in conscious rats. Intravenously administered beraprost sodium (0.01-0.3 microgram/kg) reduced the recovery time of decreased pulse pressure by topical cooling of the leg in anesthetized rats. In conscious rabbits, intravenous infusion of beraprost sodium (10 micrograms/kg/min) inhibited the fluctuation of ear artery diameter, and dilated the ear artery and vein, resulting in a rise in the ear temperature. In anesthetized dogs, intravenously administered beraprost sodium (0.313-5 micrograms/kg) caused decrease in femoral blood flow and muscle blood flow in the hindlimb, however, it caused increase in skin blood flow at the hind leg instep. Furthermore, intra-arterially administered beraprost sodium (0.1-0.3 microgram/kg/min) under stimulation of lumbar sympathetic nerve caused increase in femoral artery blood flow and selective increase in the skin blood flow without affecting muscle blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Alprostadil↗
PubMed1989

[Reverse redistribution in the stress thallium scan--correlation of coronary blood flow and myocardial damage].

In order to make clear 'reverse redistribution (RR)' phenomenon in stress thallium scan we investigated 477 consecutive patients who were consisted of 74 cases with PTCA (PTCA group), 86 cases with coronary artery bypass graft (CABG group) and 317 cases without any revascularization (N group). RR was detected in 12 cases out of PTCA group (16%), in 11 cases out of CABG group (13%) and in 10 cases out of N group (3.2%), and the incidence of RR in PTCA or CABG group was higher than that of N group (p less than 0.01). In 33 patients with RR the cases without significant coronary artery stenosis were more than those with stenosis (p less than 0.01) and the cases with myocardial damage were more than those without damage (p less than 0.01). In quantitative analysis washout rate at the RR areas showed relatively high value, but it was not significant compared with normal value (53 +/- 9.0% vs. 49 +/- 1.9%). In conclusion, RR had a tendency to appear in the condition of normal myocardium mingled with scar and of sufficient coronary blood flow. The mechanism of the phenomenon was thought to be that initial uptake of thallium in the partially scarred area was as high as in the normal myocardium, but washout of thallium from its remaining normal myocardium is normal or faster so that the defect appears at the myocardium mingled with scar. Therefore existence of reverse redistribution suspects the myocardium mingled with scar and sufficient coronary blood flow to the remaining normal myocardium.

Adult↗
PubMed1989

[Clinical diagnosis and pathogenesis of myocardial infarction complicated by hypertrophic cardiomyopathy: review of eight cases].

Among 144 patients with hypertrophic cardiomyopathy, eight (58.3 +/- 7.0 years, M:F = 7:1) had complicating myocardial infarction, which was diagnosed clinically and by elevated cardiac enzymes or new Q-waves on electrocardiography. Coronary occlusion or stenosis evidenced by coronary angiography and nuclear cardiological findings were investigated. In six of the eight patients, coronary atherosclerosis caused infarction. These patients had many coronary risk factors compared to the other two patients. Sixteen of the 144 patients (11%) with hypertrophic cardiomyopathy had coronary atherosclerosis, the rate of which is reportedly 10 to 20%. Two of the eight patients had no coronary atherosclerosis. One patient had a diffusely spastic diathesis provoked by the intravenous administration of ergonovine maleate during coronary angiography, suggesting that coronary spasm caused myocardial infarction. The other patient had recurrent episodes of supraventricular tachyarrhythmia and no evidence of spasm during coronary angiography, suggesting coronary embolism as a cause of myocardial infarction. Myocardial infarction in patients with hypertrophic cardiomyopathy and normal coronary arteries as advocated by Maron et al. may have such pathogenesis. We conclude that coronary angiography may be mandatory in patients with hypertrophic cardiomyopathy, especially those who have many coronary risk factors and anginal symptoms. In these patients, ST-T changes and abnormal Q-waves on electrocardiography sometimes may be misleading when diagnosing the occurrence of acute myocardial infarction by electrocardiography alone. In such cases, infarct-avid scintigraphy with 99 m-Tc pyrophosphate is preferable.

Adult↗
PubMed1989

Phosphorylation of the tumor suppressor gene RB protein by M-phase specific histone H1 kinase.

We have noted the presence of the consensus amino acid sequence for phosphorylation by M-phase specific histone H1 kinase in six sites of the tumor suppressor gene retinoblastoma (RB) protein and determined whether or not RB protein is, in fact, phosphorylated by this kinase. Highly purified enzyme was used for this purpose. Human cell extracts immunoprecipitated with anti-RB antiserum as well as RB proteins expressed in Escherichia coli cells were shown to be phosphorylated by this kinase in vitro. Synthetic peptides for the six expected sites were also phosphorylated. These results suggest the possibility that the function of RB protein is regulated by CDC2 kinase. We also noted the presence of putative phosphorylation sites by H1 kinase in a homologous region between the RB gene and L1 family repetitive sequences.

Amino Acid Sequence↗
PubMed1989

[Methicillin-resistant staphylococcal enterocolitis developed after induction chemotherapy in a case of acute promyelocytic leukemia].

A case of methicillin-resistant staphylococcal (MRSA) enterocolitis following combination chemotherapy for acute promyelocytic leukemia is presented. MRSA enterocolitis has characteristic clinical features of high fever, frequent vomiting and watery diarrhea, and its mortality rate is very high without a proper antibiotic therapy. When the patient with hematological malignancy has the above-mentioned clinical manifestations during antineoplastic chemotherapy, appropriate antibiotics for MRSA should be promptly begun before a bacteriological diagnosis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

[A case report of central pontine and extrapontine myelinolysis which occurred during pregnancy and was accompanied by choreic movement].

A 25-year-old female in the 17th week of pregnancy was diagnosed by MRI as having central pontine and extrapontine myelinolysis. Serial observations with MR showed gradual disappearance of the lesions in the pons and striatum. Improvement of the symptoms took place shortly before disappearance of the lesions on MRI pictures. The initial symptoms were consciousness disturbance, cranial nerve palsy and tetraparesis. Before the latter disappeared seven months after occurrence of the disease, all other symptoms gradually improved. They were followed by delayed appearance of choreic movements, which was still remaining one year after discharge. It is rare for a pregnant woman to be attacked by central pontine myelinolysis. Moreover, very few symptoms caused by such extrapontine lesions have so far been reported. Also, a review of the relevant literature by the authors found no other case showing choreic movements. This report is of an extremely rare case of central pontine and extrapontine myelinolysis which occurred during pregnancy and is accompanied by choreic movements.

Adult↗
PubMed1989

[Ultrasound imaging of the muscle in muscular dystrophy].

Ultrasound imaging of muscle was performed on 40 patients of Duchenne muscular dystrophy on lower and upper extremities. In the control subjects, there was good visualization of bone and fascia with echo-free muscle tissue. With progression of the disease, the muscle echo was increased with corresponding loss of fascia echo in muscular dystrophy. A few advanced cases showed relatively echo-free muscle because of diffuse adipose tissue infiltration. Ultrasound imaging can reveal the muscular lesion and its distribution, and is valuable for monitoring the progression of the disease.

Adolescent↗
PubMed1989

Inactivation of the N-myc gene product by single amino acid substitution of leucine residues located in the leucine-zipper region.

To verify the importance of the hypothetical leucine-zipper structure in the N-myc protein, a series of mutants of the mouse N-myc gene were constructed, in which codons for the first and second leucine residues within this structure were systematically replaced by other amino acids. The expression plasmids which contained the mutated and wild type N-myc genes were cotransfected into rat embryo cells with activated c-Ha-ras gene and their transforming abilities were compared. It was shown that single amino acid substitutions in the leucine-zipper region inactivate the transforming ability of the N-myc gene product. In particular, proline, which is known to disrupt an alpha-helical structure, completely inactivated the transforming activity even when it was substituted for another amino acid located between these two leucine residues. Among several amino acid species used for substitution of the leucine residues, only methionine was able to retain the transforming activities in both the first and second leucine positions, although the activity was reduced as compared with wild-type N-myc gene product. It also appeared that the integrity of the first leucine is more important than the second leucine. Our results provide experimental evidence for the physiological importance of the hypothetical leucine-zipper structure.

Animals↗
PubMed1989

[The successful surgery of lung abscess formed from pulmonary aspergilloma in a patient with recurrence of acute promyelocytic leukemia during remission induction therapy].

This is a case report of a successful case of surgical treatment of a lung abscess formed from pulmonary aspergilloma in a patient with a recurrence of acute promyelocytic leukemia during remission induction therapy. A 39 year-old woman was admitted to our hospital for remission induction therapy of a recurrence of acute promyelocytic leukemia. We were successful in bringing her to a state of complete remission by a therapy of a intermediate-dose of Ara-C. Pulmonary aspergilloma was formed in the right lung during therapy. We performed transbronchial infusions to Amphotericin B which dissipated the fungus ball. However, a lung abscess was formed. We needed radical therapy, and there were no complications in the following surgical treatment. Recently, along with the tendency for the use of stronger chemotherapy treatment regimes for acute leukemia, there has been an increase of the number of mycosis cases such as the pulmonary aspergilloma case reported here. Accordingly, surgical treatment is becoming more and more a matter of necessity in the clinical course of leukemia patients.

Adult↗
PubMed1989

[Clinical evaluation of a new oral cephem, cefpodoxime proxetil in children].

Cefpodoxime proxetil (CPDX-PR, CS-807) was evaluated for its efficacy, safety and pharmacokinetics in children. CPDX-PR was effective in 93.6% of 47 cases with respiratory tract, middle ear, skin or urinary tract infections. Twice or 3 times daily administration of 3 mg/kg each was sufficient to treat streptococcal pharyngitis and Haemophilus influenzae infections. No severe adverse reaction was encountered in 52 cases treated with CPDX-PR. The serum half-life was approximately 2.17 +/- 0.24 hours after oral administration.

Administration, Oral↗