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Biomedical subjects

K Tsuchiya

Publications and source records attributed to K Tsuchiya.

At least 451 records · Page 25Linked to original sources

Immunological and molecular comparison of simian cytomegaloviruses isolated from African green monkey (Cercopithecus aethiops) and Japanese macaque (Macaca fuscata).

Simian cytomegaloviruses (CMV) isolated from African green monkeys and Japanese macaques were compared serologically and genetically. Twenty-three out of 31 sera from Japanese, Taiwan and rhesus macaques were positive for neutralizing antibodies to simian CMVs isolated from both African green monkeys and a Japanese macaque. The neutralizing antibody titers of those sera were slightly higher to the isolates of African green monkeys origin than to that of Japanese macaque origin. Studies with antisera prepared in guinea pigs revealed a partial antigenic cross-reaction between Japanese macaque CMV (JaM-CMV) and African green monkey CMV (AGM-CMV): the antiserum to JaM-CMV neutralized both homologous JaM-CMV and heterologous AGM-CMV, but the antisera to AGM-CMV neutralized only homologous AGM-CMV. DNAs of both AGM-CMV and JaM-CMV were compared by restriction endonuclease cleavage analysis. The individual simian CMV isolates showed unique restriction patterns when cleaved with EcoRI, BamHI, or HindIII. In addition, DNA of JaM-CMV was distinguishable from that of AGM-CMV when cleaved with EcoRI or BamHI.

Animals↗

Treatment of chronic non-A non-B hepatitis with human interferon beta: a preliminary study.

Twenty-four patients with chronic non-A non-B hepatitis were randomly assigned to receive either human fibroblast interferon (HuIFN-beta) at doses of 1 or 3 million international units (MIU) per day for 4 or 12 weeks (12 patients) or to receive no therapy (12 patients), and were then compared with 5 patients with chronic type B hepatitis who were treated with HuIFN-beta. Elevated serum aminotransferase levels decreased more rapidly during the treatment of chronic non-A non-B hepatitis than of chronic hepatitis B. Variations in serum aminotransferases were not observed in any of the untreated chronic non-A non-B hepatitis patients. In 3 of the 9 patients with chronic non-A non-B hepatitis who responded to HuIFN-beta therapy, serum aminotransferase levels remained normal 15, 21 and 31 months after therapy was discontinued; liver biopsy specimens obtained after therapy from 2 patients showed marked histological improvement. In the six other patients aminotransferase activity levels became again elevated following cessation of interferon therapy. No response to HuIFN-beta was seen in the remaining 3 patients with chronic non-A non-B hepatitis.

Adult↗

Correlation of serum inhibin concentrations with results in an ovarian hyperstimulation program.

In order to appraise follicular development, human serum inhibin was measured daily by radioimmunoassay in 18 women undergoing ovarian hyperstimulation. Serum inhibin in the early follicular phase correlated with the number of follicles greater than or equal to 17 mm in diameter (r = 0.57, n = 18, P less than 0.05), follicles greater than or equal to 14 mm in diameter (r = 0.67, n = 18, P less than 0.01) on the day of human chorionic gonadotropin (hCG) administration and the number of oocytes retrieved (r = 0.67, n = 15, P less than 0.01). The number of oocytes retrieved showed a significant correlation with serum inhibin level on the day of hCG administration (r = 0.84, n = 15, P less than 0.001). These data suggest that: (1) In the early follicular phase, serum inhibin may be a valid index to predict ensuing follicular growth; (2) In the preovulatory phase, serum inhibin may be one of applicable indexes of follicular development during the hyperstimulation cycle.

Adult↗

Human monoclonal antibodies against cytokeratin 18 generated from patients with gastric cancer.

By co-culturing regional lymph node B-cells and HAT-sensitive mutant cells obtained from RPMI-1788 cells, no less than 20,000 Epstein-Barr (EB)-transformed colonies were obtained from 32 patients with gastric cancer. From B-cell cultures generating antibodies reactive with gastric cancer tissues as well as cultured gastric cancer cells, two EB-transformed cell clones termed C418-59 and C1218-39 were isolated. Both of them produced human IgM-class antibodies, termed Mab418-59 and Mab1218-39, respectively. Both antibodies reacted with an antigen with a molecular weight of 45 kd existing in gastric cancer MKN-45, MKN-1, and Kato-III cells, and also with all of 4 adenocarcinomas of the stomach in paraffin sections. The antigen recognized by both antibodies was identified as a kind of cytoskeletal protein, cytokeratin 18. In this study, it was confirmed that B-cell clones generating autoantibodies against cytokeratin 18 were present in some patients with gastric cancer.

Adenocarcinoma↗

High homology between 6-aminohexanoate-cyclic-dimer hydrolases of Flavobacterium and Pseudomonas strains.

The nucleotide sequences of the genes for 6-aminohexanoate-cyclic-dimer hydrolases of Flavobacterium sp. strain K172 (F-nylA) and Pseudomonas sp. NK87 (P-nylA), enzymes essential for the degradation of a by-product of the nylon-6 industry, were obtained by the dideoxynucleotide chain-termination method. A 1,479-base-pair open reading frame starting at a GTG and terminating at a TGA was found for the both of the genes. The P-nylA and F-nylA genes encoded polypeptides of 493 amino acids and had only 10 base substitutions in the coding region, which caused seven amino acid substitutions.

Amidohydrolases↗

[Effects of propiverine hydrochloride and its metabolites on isolated guinea pig urinary bladder].

The effects of P-4 and its active metabolites in human blood and urine and the effects of 1-methyl-4-piperidyl diphenylpropoxyacetate N-oxide [P-4(N----O)], 1-methyl-4-piperidyl benzilate N-oxide [DPr-P-4(N----O)] and 1-methyl-4-piperidyl benzilate (DPr-P-4) on isolated guinea pig urinary bladder were investigated. At doses of 10(-6) or 10(-5) M, P-4 shifted the dose-response curve for acetylcholine (ACh) to the right, and at a dose of 10(-5) M, it also inhibited the maximum response of ACh. At doses of 10(-5) M or more, P-4(N----O) inhibited the maximum response of ACh. DPr-P-4(N----O) or DPr-P-4 shifted the dose-response curve for ACh to the right at doses of 10(-6)-10(-4) M or at doses of 10(-7)-10(-5) M. P-4 at doses of 10(-6) M or more inhibited the KCl (100 mM)-induced contraction in a dose-dependent manner, and its potency was quite equal to that of terodiline. The inhibitory effect of P-4(N----O), DPr-P-4(N----O) and DPr-P-4 in the KCl (100 mM)-induced contraction were weaker than that of P-4. P-4 and P-4(N----O) had a dose-dependent inhibitory effect on K+-induced 45Ca influx in isolated guinea-pig urinary bladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

Arthrography of early Perthes' disease. Swelling of the ligamentum teres as a cause of subluxation.

Hip arthrography was performed in 19 patients in the initial stage of Perthes' disease. Sphericity and subluxation were measured and it was found that subluxation was independent of the femoral head deformity. We therefore tried to identify the cause of early subluxation: in seven patients a swollen ligamentum teres was thought to be responsible, and was associated with medial pooling of the contrast medium. A swollen ligamentum teres was seen in another seven cases; the other five arthrograms were normal. These findings were further clarified by enhanced CT scans, which confirmed that ligament swelling may be an important cause of early subluxation.

Arthrography↗

Natriuretic and diuretic effects of endothelin in isolated perfused rat kidney.

In an attempt to clarify the pathophysiological role of endothelin (ET), a novel vasoconstrictor peptide, we administered this peptide into the medium of isolated perfused rat kidney (IPK). ET increased renal vascular resistance by 53%, and reduced inulin clearance by 29% in IPK at a higher concentration of 500 PM. However, fractional excretion of sodium and urine flow rate were increased by 160% and 109%, respectively. These findings suggest that ET modulates the tubular sodium reabsorption as well as the renal hemodynamics.

Animals↗

Effects of atrial natriuretic peptide on regional renal blood flow measured by a thermal diffusion technique.

The effects of atrial natriuretic peptide (ANP) on the regional renal blood flow were examined in anesthetized dogs. A thermal diffusion technique was applied in an attempt to observe the intrarenal blood distribution. Tissue blood flow was continuously measured according to the changes of the thermal gradient produced by a semiconductor (Peltier effect). The data (x) obtained by these probes were closely related to those (y) of the ion gas clearance method (the probe for cortical blood flow; y = 1.08x-6.23 r = 0.99, the probe for medullary blood flow; y = 1.00x +0.26 r = 0.99). The basal values of cortical and medullary blood flows measured with the flow probe in anesthetized mongrel dogs were 85 +/- 16 and 55 +/- 9 ml/min/100 g kidney weight, respectively. ANP was infused into renal artery at doses of 0.01 (n = 6), 0.05 (n = 8), 0.3 (n = 6) micrograms/kg/min and the effect on renal hemodynamics and renal excretory functions was observed. The effect was also compared with that of furosemide. Low dose of ANP did not affect renal blood distribution. Intermediate dose of ANP selectively increased medullary blood flow from 46 +/- 8 to 62 +/- 7 ml/min/100 g kidney weight, and higher dose significantly increased both cortical and medullary blood flow. ANP produced diuresis and natriuresis in a dose-dependent manner, which was not necessarily related to the changes of intrarenal blood distribution. Furosemide did not affect the renal hemodynamics. Several parameters of renal functions such as lithium and free water clearances, showed changes different from those with ANP infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Renal and hemodynamic effects of synthetic atrial natriuretic peptide in dogs with chronic renal failure.

The present experiments were performed to clarify the renal and hemodynamic effects of atrial natriuretic peptide (ANP) in dogs with chronic renal failure (CRF; produced by 5/6 nephrectomy 3-4 weeks before study). Synthetic alpha-hANP was administered intravenously (0.1 micrograms/kg body weight for 30 min) with a priming bolus injection (1.0 micrograms/kg body weight) to anesthetized controls (n = 8) and CRF-dogs (n = 10). The effects of ANP on renal function, cardiac function, lithium clearance, and plasma ANP levels during clearance studies were determined. Effects of ANP on the hemodynamics were observed to the same degree in both groups. An increase in inulin clearance (CIn) was noted only in the CRF-dogs (7.5 +/- 2.1 to 9.6 +/- 2.9 ml/min; p less than 0.01). The infusion of ANP increased the urine volume, absolute sodium excretion, and osmolar clearance in the control and CRF groups. The fractional excretion of lithium (FELi), a marker of the proximal reabsorption of sodium, was higher at baseline in the CRF group (control group, 24.4 +/- 6.7 vs. CRF group, 41.5 +/- 13.2%; p less than 0.001). Following ANP infusion, FELi increased in both groups. The plasma ANP levels were monitored during the clearance study, and those of the CRF group were higher throughout the experiments. Thus, extrinsic ANP induced diuresis and natriuresis in CRF-dogs, produced by nephron mass reduction. Discrepancies in the pattern of response and plasma ANP levels were observed between the controls and CRF-dogs, suggesting that the action and metabolic clearance rate of ANP were altered in the CRF state.

Animals↗

Role of atrial natriuretic peptide on sodium homeostasis in experimental renal failure.

In a study of the role of atrial natriuretic peptide (ANP) in sodium homeostasis in experimental renal failure, we found that a infusion of ANP at 0.25 microgram/min for 15 min produced an increase in the glomerular filtration rate (GFR) and fractional excretion of sodium (FENa) in five-sixth nephrectomized (5/6 Nx) rats. Renal vascular resistance (RVR) was lower during the base-line period and did not change after the administration of 100 ng/ml ANP to isolated perfused kidney (IPK) from adriamycin-treated rats. Furthermore, fractional excretion of ANP (FEANP) by IPK decreased in kidneys from adriamycin-treated rats as compared to that in kidneys from control rats. Finally, after 5/6 Nx, levels of plasma immunoreactive ANP (ir-ANP) gradually increased but excretion of water and sodium did not change during normal intake of sodium. The increase in levels of ir-ANP was accompanied by an increase in the rates of excretion of water and sodium was observed 2 days later but these rates returned to the base-line values after 2 weeks. These findings suggest that ANP plays an important role in the adjustment of acute changes in the volume of extracellular fluid during experimental renal failure.

Animals↗

Unique male mammary tumors developing in the inbred soft-furred field rats Millardia meltada.

Inbred lines of the soft-furred rat, Millardia meltada, were studied with special reference to spontaneous male mammary tumors. Adult males had the hyperplastic, pigmented inguinal mammary tissues and frequently developed bilateral mammary tumors. The tumors, no longer pigmented, were histologically well-differentiated adenocarcinomas associated with the myoepithelial cells and showed a variety of growth patterns depending on the stage of progression. They were transplantable to male, but not to female or castrated male nude mice. A significant number of androgen as well as estrogen binding sites were demonstrated in the nuclei of the transplanted tumor cells by in situ autoradiography. Neither virus particle nor mouse mammary tumor virus-specific antigen expression was detected in the tumor cells by electron microscopic and immunohistochemical studies. Normal females were generally free of pigment and tumor, although the androgen treatment induced marked pigmentation (deposit of nonfluorescent lipofuscin and hemosiderin) and hyperplasia of the female mammary epithelial cells, without a tumor. Possible relationships between pigmentation and tumor development were considered.

Animals↗

[MR findings of metastatic brain tumors].

Fifteen cases with metastatic brain tumor(s) were examined on a 1.5T MR system and the results were evaluated along with images of contrast-enhanced CT. Gd-DTPA-enhanced T1-weighted imaging (T1WI) showed the best detectability of lesions and was followed by contrast-enhanced CT, T2WI, and non-enhanced T1WI in that order. No correlation was found between the MR signal intensity and the histological classification of the tumors. In differential diagnosis with glioblastoma, several signal characteristics were encountered. Low or isointensity as well as the discrimination of tumor from edema on T2WI was considered to suggest the diagnosis of metastatic tumor.

Adult↗

[Subdural hematoma from ruptured arteriovenous malformation; demonstration by MR imaging].

We studied MRI of 15 cases of arteriovenous malformation (AVM) with special reference on the coexistence of the subdural hematoma. All ruptured cases (6 cases) were associated with intracerebral hematoma, and half (3 cases) of them were coexisted with subdural hematoma. In one of them, the presence of the subdural hematoma promoted us to perform angiography which revealed the AVM.

Adolescent↗

A quasistatic study of pupil and accommodation after-effects following near vision.

The study examines the effect of a near task on immediate post-task measures of pupil size and accommodative state. The method of quasistatic measurement of accommodation was used and pupillary changes elicited by the accommodative stimulus were simultaneously recorded using an infrared video-pupillometer. This method requires a short (typically 2 minutes) but strong (up to 10 D in most subjects) near-vision effort, with the accommodative and pupillary responses being recorded before, during, and after the task. The results show pupil after-effects to be more pronounced than tonic accommodative after-effects. Inter-individual difference in after-effects is large. The pupil after-effect was dissociated from the tonic accommodation after-effect and lasted in some cases for more than 15 minutes. The pupil after-effect was not masked by darkness. It is proposed that monitoring the changes of pupil is valuable when assessing the after-effects of sustained near vision.

Accommodation, Ocular↗

[An autopsy case of panencephalopathic type of Creutzfeldt-Jakob disease: an early clinical sign documented by magnetic resonance imaging].

We reported an autopsy case of panencephalopathic type of Creutzfeldt-Jakob disease (CJD), one of whose early clinical signs, visual loss, had been documented by magnetic resonance imaging (MRI). The patient was a 59-year-old woman, who showed disturbance of visual acuity, memory and calculation at the early stage. About 2 months later she developed apallic syndrome and revealed myoclonic jerks in her eye balls, face, neck and extremities. Electroencephalography showed periodic synchronous discharge. Three months later after her first symptoms MR showed bilateral occipital atrophy, although we could find no brain atrophy on CT scan. She died of the suffocation caused by bronchopneumonia at the age of 60 years. The total duration of her illness was about 20 months. Neuropathological examination revealed a pronounced diffuse atrophy of the cerebral cortex and white matter. In addition to severe cortical neuronal loss and astrocytosis, spongiform changes were evident. The hippocampus was relatively well preserved. In the cerebral white matter both myelin sheaths and axons disappeared almost completely. The cerebellum showed the severe degeneration of granule cells. These neuropathological findings are consistent with those of panencephalopathic type of CJD. It is important to clarify the abnormalities of MR findings in relation to such early clinical signs of CJD. To the best of our knowledge such reports as ours have not been published previously.

Atrophy↗