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Biomedical subjects

N Imai

Publications and source records attributed to N Imai.

At least 91 records · Page 5Linked to original sources
PubMed1995

Craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and other features.

A case of craniosynostosis with joint contractures, ear deformity, cleft palate, scoliosis, and many other features is presented. The patient's skull was round with craniosynostosis of the coronal suture. The fingers were slender and long; the finger joints were contracted. Trismus was also present. Contracture of the temporomandibular joint was suspected. The helices were flat, antihelices were minimal, and the ears protruded. Furthermore, the facial and cranial features of this patient included mild hypertelorism, ocular proptosis, short pons nasi, flat radix nasi, mild retrognathia, and small oral fissure. In the oral cavity, a relatively wide cleft extended from the soft palate to the uvula. A frontal chest radiograph revealed a mild scoliosis. Differential diagnoses are discussed in reported syndromes with craniosynostosis.

Abnormalities, Multiple↗
PubMed1995

[A case of metamorphopsia caused by a very localized spotty infarct].

A 51-year-old woman complained that her right side of the face looked blurring and the right margin of all the objects in her visual field looked blurred. Neurological examination on admission showed no abnormalities including higher cortical function and visual fields except the metamorphopsia. In this case, a very localized spotty infarct caused no neurological symptoms other than the metamorphopsia. CT scan and MRI revealed a spotty lesion of infarct between retrosplenium and cingulate gyrus on the left side. This can be a breakthrough case to locate the exact anatomic pathology that causes metamorphopsia.

Cerebral Infarction↗
PubMed1995

[Magnetic resonance imaging of renal lymphoma with computed tomography correlation].

The magnetic resonance (MR) imaging and computed tomography (CT) findings in four patients (five kidneys) with non-Hodgkin's lymphoma involving the kidneys and perirenal spaces are presented. The patterns of disease in each case were as follows: bilateral renal nodules, infiltration in the perirenal space, infiltration in the perirenal space with renal involvement, and direct invasion from contiguous retroperitoneum. On plain CT, the lesions showed slight hyperdensity (three kidneys) and isodensity (two kidneys) as compared with normal renal parenchyma. But all lesions appeared as hypodense masses with more definite margins after contrast enhancement. MR imaging findings showed iso- or slight hypointense masses on T1-weighted images and definite hypointense masses on T2-weighted images as compared with the signal intensity of the renal cortex. Dynamic imaging and conventional delayed T1-weighted imaging following Gd-DTPA injection showed no significant enhancement of the lesions. In comparison with contrast enhanced CT, despite its poorer resolution, T2-weighted MR imaging showed nearly the same accuracy in the evaluation of number and extent of the lesions without contrast medium administration. MR imaging was also useful to evaluate the patency of vessel lumen surrounded by tumor mass and to determine the location and extent of huge lesions by its multiplanar imaging capabilities.

Aged↗
PubMed1995

Oxygen and carbon dioxide requirements of Helicobacter pylori.

The oxygen and carbon dioxide requirements of 25 clinical isolates of Helicobacter pylori were studied in relation to pyruvate metabolism. A maximal number of 16 strains grew without added carbon dioxide under an atmosphere containing 6% oxygen and 0.04% ambient atmospheric carbon dioxide contrary to a generally accepted idea. Enzymes acting on pyruvate as a parameter of the ATP regeneration system were only pyruvate:ferredoxin oxidoreductase (EC 1.2.7.1) and pyruvate formate-lyase (EC 2.3.1.54). The microaerophilism may be partly due to the conversion of pyruvate to acetyl-CoA by the two anaerobic enzymes, although the organism requires oxygen.

Carbon Dioxide↗
PubMed1994

A novel cytokine exhibiting megakaryocyte potentiating activity from a human pancreatic tumor cell line HPC-Y5.

Sixty-four kinds of cell lines were examined for their ability to produce megakaryocyte potentiating activity by means of conditioned media obtained from a protein-free culture system. Six human tumor cell lines were shown to produce this activity, and the cell line HPC-Y5, established from human pancreatic cancer, was shown to have the highest level of activity. The megakaryocyte potentiating factor (MPF) was purified from an HPC-Y5 conditioned medium by a combination of ion-exchange chromatography, gel filtration and reverse-phase HPLC. The purified MPF showed a megakaryocyte potentiating activity almost equal to human interleukin-6 in the presence of murine interleukin-3 in a colony formation assay with mouse bone marrow cells. The apparent molecular weight of MPF is 32,000 when determined by SDS-polyacrylamide gel electrophoresis. Glycopeptidase F digestion, and amino sugar analysis of the factor demonstrated that MPF is a glycoprotein carrying at least one N-linked sugar chain. The N-terminal amino acid sequence of MPF was determined to be Leu-Ala-Gly-Glu-Thr-Gly-Gln-Glu-Ala-Ala-Pro-Leu- Asp-Gly-Val-Leu-Ala-Asn. The same or homologous amino acid sequence has not been found in known proteins, demonstrating that MPF is a novel cytokine that has megakaryocyte potentiating activity in the murine assay system.

Amino Acid Sequence↗
PubMed1994

Short-term effects of naloxone on hemodynamics and baroreflex function in conscious dogs with pacing-induced congestive heart failure.

OBJECTIVES: The purpose of this study was to determine the effects of naloxone on systemic hemodynamics and reflex function in dogs with congestive heart failure induced by rapid pacing. BACKGROUND: We have shown previously that naloxone, an opiate receptor antagonist, improves cardiac output, aortic blood pressure, systolic performance and the baroreflex function in conscious dogs with chronic right-sided congestive heart failure. However, whether endogenous opioids also play a role n mediating the reduction of myocardial and baroreflex function in animals with left heart failure remains controversial. METHODS: We administered naloxone (1 mg/kg body weight) and normal saline solution to 15 dogs with pacing-induced congestive heart failure (225 beats/min for 8 weeks) and 11 control dogs. In addition to systemic hemodynamic measurements, the slope of pressure-area relation obtained from echocardiography with intravenous bolus injection of phenylephrine was taken as a load-independent index of myocardial contractility. Baroreflex function was estimated by the slope of the regression line relating systolic aortic pressure and RR interval. RESULTS: Plasma beta-endorphin levels were elevated in dogs with congestive heart failure. Naloxone administration increased heart rate, mean aortic pressure, first derivative of left ventricular pressure, cardiac output and myocardial contractility in pacing-induced congestive heart failure. These changes correlated significantly with basal plasma beta-endorphin levels and were accompanied by increases in plasma beta-endorphin and catecholamines after naloxone administration. However, unlike the hemodynamic and cardiac effects of naloxone, baroreflex function did not change after naloxone in dogs with congestive heart failure. CONCLUSIONS: The increase in basal plasma beta-endorphin suggests that the endogenous opiate system is activated in left-sided congestive heart failure. Because naloxone improves the systemic hemodynamics and myocardial contractile function under this condition, the endogenous opioids appear to play an important role in mediating the myocardial depression that occurs in heart failure. However, the endogenous opiate system has no apparent effect on the regulation of baroreflex control in heart failure induced by rapid pacing.

Animals↗
PubMed1994

Comparison of cardiovascular effects of mu- and delta-opioid receptor antagonists in dogs with congestive heart failure.

We have shown previously that right heart failure (RHF) in dogs is associated with activated endogenous opiate systems, and that administration of the opioid receptor antagonist, naloxone, increases arterial pressure, cardiac contractile function and organ blood flows. To study whether the cardiovascular effects of naloxone are mediated via the mu- or delta-opioid receptors, we administered ICI-154,129, a delta-receptor antagonist, and naloxonazine, a mu-receptor antagonist, to 10 conscious dogs with RHF on 2 separate days. Like naloxone, ICI-154,129 increased mean aortic pressure, cardiac output, peak positive first derivative of left ventricular pressure, and blood flows to the myocardium, kidneys, splanchnic beds, and skeletal muscle. These changes were associated with increases in plasma epinephrine and norepinephrine. In contrast, naloxonazine had no effects on systemic hemodynamics, regional blood flow distribution, and plasma catecholamines in RHF. These findings suggest that the increased endogenous opioids during heart failure act on the delta-opioid receptors to decrease myocardial mechanical performance and alter regional blood flow distribution. Opioid receptor-blocking agents may exert beneficial cardiovascular effects in heart failure.

Animals↗
PubMed1994

Expression of the human multidrug resistance gene (MDR1) and prognostic correlation in human osteogenic sarcoma.

The overexpression of P-glycoprotein (P-Gp), encoded by the human multidrug resistant gene (MDRA), decreases lipophilic drug accumulation in multidrug resistant cells in vitro. It is still not clear whether P-Gp contribute to the problem of multidrug resistance (MDR) in osteogenic sarcoma (OS). We examined the MDR1 expression of 20 OS specimens (11 primary tumors, 10 xenografts, 1 overlapping), by Northern blotting and by the reverse transcriptase-polymerase chain reaction (RT-PCR), and evaluated by the relationship between MDR1 expression and patient prognosis. RT-PCR revealed MDR1 expression in 9/20 OS; 5/11 primary tumors and 5/10 OS-xenografts; northern blotting revealed MDR1 expression in only 5/20 OS. One primary OS specimen and its corresponding xenograft had similar levels of MDR1 expression. All 20 patients with OS were treated with chemotherapeutic protocols including doxorubicin, cisplatin, methotrexate and ifosfamide. Eight of 9 OS-patients expressing MDR1 were resistant to chemotherapy and had a poor prognosis. The relationship between MDR1 expression and poor prognosis in the 20 OS-patients was significant (p < 0.01). The results support the assumption that MDR1 expression is related to MDR in human OS.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

[A Japanese pedigree with oculopharyngeal muscular dystrophy].

We investigated a Japanese pedigree with oculopharyngeal muscular dystrophy (OPMD) which included the probands of two sisters and a brother. Case 1 (Fig. 1): A woman born in 1940 at Fuji City, Shizuoka prefecture (Pacific coast side, which located about 80 miles west from Tokyo) was insidiously suffering from dysphagia and eye lid ptosis since her age of 40. She was admitted to Shizuoka Red Cross Hospital when 48 years old, because of difficulty of going upstairs. Neurological examination revealed severe eye lid ptosis without eye movement disorders, dysphagia, and moderate weakness on neck and proximal muscles of extremities without definite atrophy and fasciculation. In the laboratory data, serum creatine kinase level was slightly elevated to 215 U/l. Electromyographic findings showed myogenic pattern on the extremities but no evidence of the existence of myasthenia gravis and neurogenic involvement. Intranuclear tubular filaments were found in 3% of muscle fibers from her left biceps muscle. Case 2: The elder sister of the case 1 was suffering from eye lid ptosis without eye movement disorder and severe dysphagia since the age of 44. Case 3: The younger brother of the case 1 was suffering from dysphagia and proximal muscle weakness since the age of 40. We found eye lid ptosis, dysphagia and/or proximal muscle weakness in 24 cases (men: 12 cases, women: 12 cases) out of 50 examined members of this pedigree after their ages of 40 (Fig.3; family tree). It was concluded that this pedigree had cases of oculopharyngeal muscular dystrophy with autosomal dominant inheritance which was quite rare in Japanese.

Female↗
PubMed1994

[Maternal working status and low birthweight: findings from a cohort study].

To explore possible associations of maternal working status with birthweight, a cohort study was conducted from July, 1989 to June, 1991 in 8 general hospitals in the Tokai district. Using a self-administered questionnaire, data on job employment were collected mostly in the first or second trimester. Information on delivery outcome was recorded by doctors, midwives or nurses after child birth. Included in this analysis were 1,360 pregnants who delivered a live singleton without major malformations at gestation of 37 weeks or more. The following major findings emerged. (1) No significant difference in mean birthweight was detected between working and non-working pregnants. (2) Working pregnants were at greater risk of delivering a low birthweight (< 2,500g) baby. (3) Delivery of a low birthweight baby was more frequent in multiparous than nulliparous mothers. (4) The risks of delivering a low birthweight baby significantly differed according to the maternal working status. (5) These results suggest that not only the maternal working factor itself but the working status should be deliberately taken into consideration in order to provide proper prenatal care.

Adolescent↗
PubMed1993

Reductions of myocardial Na-K-ATPase activity and ouabain binding sites in heart failure: prevention by nadolol.

To study the changes in myocardial digitalis binding sites in heart failure, we measured myocardial ouabain binding sites, Na-K-adenosinetriphosphatase (ATPase) activity, and ventricular muscle mechanical responses to acetylstrophanthidin in dogs with right-heart failure (RHF) produced by tricuspid avulsion and pulmonary artery constriction. Sham-operated dogs were studied as the control. RHF produced a significant decrease in ouabain binding sites in the right and left ventricular myocardium, which was accompanied by a proportional decrease in Na-K-ATPase activity. However, RHF and sham-operated dogs did not differ in systemic hemodynamic or right ventricular trabeculate muscle isometric contractile responses to acetylstrophanthidin. To determine whether chronic beta-adrenergic stimulation contributed to the development of Na-K-ATPase downregulation, we administered nadolol (40 mg/day) to a separate group of dogs during an early stage of RHF development. Nadolol effectively prevented the reduction of myocardial ouabain binding sites that occurred in RHF. Thus we conclude that myocardial ouabain binding sites and Na-K-ATPase activity are reduced in dogs with experimental heart failure and that these changes probably occur as a result of the attendant heightened sympathetic activity.

Animals↗
PubMed1993

Distinct responses of interleukin-6 and other laboratory parameters to treatment in a patient with Wegener's granulomatosis.

We describe a patient with Wegener's granulomatosis in whom the serum levels of interleukin-6 (IL-6) and other laboratory parameters were monitored. The IL-6 and CRP levels, which were extremely high before treatment, declined rapidly with corticosteroid and cyclophosphamide. IgG, leukocyte count and platelet count declined more gradually. Thus, determination of the serum IL-6 level might be useful in diagnosing and monitoring Wegener's granulomatosis.

Biomarkers↗
PubMed1993

Acute myeloid leukemia possibly producing thrombopoietic factor(s).

A 75-year-old man developed a cluster of differentiation (CD)4-positive but human T-cell lymphotropic virus type I (HTLV-I)-negative T lymphoid neoplasm with overwhelming cutaneous involvement and mild thrombocytosis. Twelve courses tetrahydropyranyl adriamycin, cyclophosphamide, vincristine and prednisone (THP-COP) combination chemotherapy led him to complete remission. After four months of complete remission, however, atypical immature cells (blasts) appeared in peripheral blood and bone marrow. Surface marker analysis revealed the blasts to be CD2-, CD3-, CD4-, CD5-, CD7+, CD8-, CD10, CD13 +/-, CD19-, CD20-, CD25-, CD33+ and human leukocyte antigen-DR (HLA-DR+). Staining for myeloperoxidase, esterases, PAS and platelet peroxidase were all negative. The patient was diagnosed as having both CD7 and CD33 positive acute myeloid leukemia (AML). The relation between the T cell lymphoid neoplasm and AML was not clear. Thrombocytosis became more marked after acute leukemia occurred and the platelet count varied in parallel with the blast cell count in peripheral blood. When the leukemic cell count was high, thrombopoietic activity could be detected in the serum. In addition, conditioned medium obtained from primarily-cultured blasts had detectable thrombopoietic activity, which implied the blasts directly to produce a thrombopoietic factor(s). Analysis of the serum concentration for cytokines with associated thrombopoietic activity indicated that the blasts possibly produced a thrombopoietic factor(s) distinct from interleukin (IL)6, IL3, leukemia inhibitory factor (LIF), erythropoietin and granulocyte macrophage-colony stimulating factor. To our knowledge, this is the first reported case of an acute myeloid leukemia with marked thrombopoiesis (more than 2000 x 10(3)/microliter of maximum platelet count in peripheral blood.

Acetylcholinesterase↗