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T Higuchi

Publications and source records attributed to T Higuchi.

At least 271 records · Page 15Linked to original sources
PubMed1998

Bestatin, an aminopeptidase inhibitor, promotes follicular growth and ovulation suppressed by stress in mice.

We previously reported that the intraperitoneal and intrabursal administration of bestatin, an aminopeptidase inhibitor, enhanced follicular growth and ovulation in immature mice. In this study, we examined the effect of bestatin on follicular growth and ovulation under the conditions in which the ovarian response to gonadotropins was suppressed. Immature female mice were exposed to 72-h continuous lighting (on days 20-22 of life), or to 24-h starvation (on day 20). On days 20-22, bestatin (4 mg/ml, 100 microl) or PBS (100 microl) was administered ip. 4 times and pregnant mare serum gonadotropin (PMSG, 5 IU) and hCG (5 IU) were given on days 21 and 23, respectively. The numbers of ovulated oocytes per mice were significantly attenuated by both stresses. Bestatin significantly enhanced the numbers of ovulated oocytes under both lighting (49.5+/-7.0 vs. 28.0+/-5.5) and starvation (28.6+/-2.6 vs. 20.2+/-2.0) stresses (with vs. without bestatin, P<0.05). When follicular development was stimulated by PMSG (20 IU) on day 21, the serum estradiol concentration on day 23 was also suppressed by both stresses, but enhanced by bestatin under lighting (231.3+/-36.0 vs. 111.0+/-23.0 pg/ml) and starvation (151.9+/-8.8 vs. 90.7+/-15.4 pg/ml) stresses (with vs. without bestatin, P<0.01). Northern blot analysis revealed that the expression of P450arom-mRNA in the ovaries induced by PMSG (20 IU) was increased on day 23 by treatment with bestatin under starvation stress. These results indicated that stress inhibited the ovarian response to gonadotropins and that bestatin restored the response suppressed by stress.

Aminopeptidases↗
PubMed1998

The application of molecular biological tools to epidemiology of African trypanosomosis.

Difficulties have often been encountered in the field surveys due to a lack of definitive morphological characters, particularly where mixed infections are expected. To address this problem, some molecular biological techniques such as DNA probe hybridization, restriction fragment length polymorphism (RFLP) analysis, the polymerase chain reaction (PCR), analyses of ribosomal DNA, and pulsed-field gel electrophoresis (PFGE), have been applied to the analysis of field samples collected during epidemiological surveys of African trypanosomosis. Concurrent natural infection of different individual tsetse flies and mammalian hosts with different species of the trypanosomes have been demonstrated, through the use of a combination of specific DNA probe hybridization and the PCR. Molecular karyotypes of Trypanosoma brucei species were analyzed by PFGE in 45 - 2,000 kb range. There are distinctive differences in intermediate and mini-chromosomes among the strains. We have compared the nucleotide sequences of ribosomal DNAs of the parasites by PCR techniques. From this data new phylogenetic tree can be inferred. It is apparent that these technologies can provide powerful tools for identification and diagnosis of trypanosomes in their hosts and vectors, and for their more accurate phylogenetic classification.

Animals↗
PubMed1998

Pentavalent technetium-99m-dimercaptosuccinic acid scintigraphy in renal osteodystrophy.

Pentavalent 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy and 99mTc-hydroxymethylene diphosphonate (HMDP) bone scan were performed in one patient with renal osteodystrophy (ROD) before and after vitamin D3 pulse therapy. The bone scan showed diffusely increased tracer uptake in the whole skeleton, and no change of tracer distribution was noted before or after vitamin D3 pulse therapy. However, 99mTc(V)-DMSA scintigraphy revealed diffusely increased tracer uptake in the whole skeleton before therapy, and markedly decreased tracer uptake in the bones was seen at 5 mo after therapy. Increased uptake of 99mTc(V)-DMSA was observed at 7 mo after therapy, which reflected the laboratory findings. Technetium-99m-(V)-DMSA scintigraphy appeared to be more sensitive than the conventional 99mTc-HMDP bone scan in assessing the characteristics and therapeutic effect of bone disease in ROD.

Adult↗
PubMed1998

[The impact of rejection episodes during acute tubular necrosis--diagnosis and allograft outcome after cadaveric renal transplants].

Diagnosis of acute rejection (AR) is difficult during acute tubular necrosis (ATN), and a delay of rejection treatment could result in negative impacts on the renal transplant outcome. At our center, 68 cadaveric kidneys were transplanted during the past 7 years. The 1-, 3- and 5-year graft survival rates were 95.4%, 93.8% and 81.4%, respectively. After the transplants, 16 patients had immediate graft function (G-I), 51 patients experienced ATN for 12.0 +/- 9.3 days, and one patient had a non-functioning graft due to diffuse arteriolar thrombosis caused by DIC in the donor. During ATN, 41 patients had no rejection episodes (G-II) and 10 patients had ARs (G-III). Nine patients were treated with bolus steroid and one with steroid and OKT-3. Although scintigraphic and sonographic examinations were routinely employed, only the histopathological findings of needle biopsies were helpful for the diagnosis of AR during ATN. When the transplant outcome was compared, the serum creatinene level was highest in G-III and lowest in G-I (1.48 vs 1.06 mg/dl, p < 0.05). The posttransplant ATN period was also longer in G-III compared to G-II (23.9 vs 9.1 days, p < 0.005). The 5-year graft survival rate was 85.2% in G-I, 88.0% in G-II and 59.3% in G-III. We conclude that routine serial renal biopsies should be scheduled when ATN develops after the cadaveric renal transplant, since only the histopathological diagnosis is reliable during ATN.

Acute Disease↗
PubMed1998

[Changes in QOL in patients with brain tumors measured by mood changes during and after treatment].

UNLABELLED: Patients with brain tumors are exposed to severe stress which may have an influence on their quality of life (QOL). To measure QOL in those patients, we measure their mood state during and after the treatments. MATERIALS: 16 patients who were admitted to our department for treatment of brain tumors, were included in the study. The tumors included 5 gliomas, 6 meningiomas and others. They were 7 males and 9 females, and age distributed from 19 to 74 years old. All patients presented more than 90% of the Karnofsky performance score (KPS) on discharge, so they were expected to return to their previous social life. METHOD: The self-answering tests were performed on admission (Pre), on discharge (Post 1), and at more than 5 months after the discharge (Post 2). The tests included an original questionnaire asking consent to admission and treatment, and concerning the feeling of disability to cope with conditions of living, Cornell Medical Index (CMI) which measured the neurosis, and Profile of mood state (POMS) which measured the 6 subscales of patients mood states including tension-anxiety (TA), depression (D), anger-hostility (AH), vigor (V), fatigue (F), and confusion (C). RESULTS: The questionnaire showed that the patients feel satisfied with having consented to the treatment. The feeling of disability to cope with living became stronger in Post 2 than in Pre. CMI showed a borderline of neurosis in three patients on admission, and in four patients in Post 2. Only the TA of POMS subscale improved significantly in Post 2. However, other subscales were unchanged. It is characteristic that all of the subscales of POMS showed less disturbance on discharge compared with that on admission, but, they returned to the Prelevel after they returned to social life. CONCLUSIONS: Patients with brain tumors have satisfactory consent to the treatment, however, they feel disability to cope with social life. On discharge, they showed a better mood state compared to that on admission, but the mood state turned for the worse again during the follow-up period. It is evident that patients with brain tumors are exposed to severe stress even after the completion of the treatment. The results necessitate our taking patients' mental health into consideration for our treatment protocol.

Adult↗
PubMed1998

[MRI, SPECT and MRS findings in a case of acute hemiplegia syndrome with a marked hemispheric brain edema].

Magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT) and magnetic resonance spectroscopy (MRS) were successively recorded in a 3-year-old girl with the acute hemiplegia syndrome. She was admitted to our hospital with complaints of fever, loss of consciousness and right side dominant clonic convulsions evolving into status epilepticus, and then recovered with sequelae of aphasia and right hemiparesis. Electroencephalography showed a generalized slow rhythm at the onset, and very low activities on the left hemisphere in the follow-up records. Brain CT and MRI revealed edema of the left hemisphere initially, followed by left side dominant brain atrophy. No cerebral vascular lesion was detected by magnetic resonance angiography. N-Isopropyl-[123I]-iodoamphetamine SPECT showed marked hypoperfusion of the left hemisphere accompanied by crossed cerebellar diaschisis. MRS at the initial stage detected decreased N-acetyl-aspartic acid and increased lactic acid signals in the bilateral hemisphere, which subsequently normalized only on the right side. These findings suggested brain damage and neural cell death in the left cerebral hemisphere, caused by acute encephalopathy. SPECT and MRS are useful new techniques to study the pathophysiology of the acute hemiplegia syndrome.

Acute Disease↗
PubMed1998

Noninvasive measurement of renal function with 99mTc-MAG3 gamma-camera renography based on the one-compartment model.

OBJECTIVE: The aim of this study was to develop a method for measuring renal function with 99mTc-MAG3 gamma-camera renography without blood or urine sampling and evaluate its feasibility. PATIENTS, MATERIAL AND METHODS: Twelve patients with nephrological disorders underwent 99mTc-MAG3 renography and para-aminohippurate clearance measurement. Plasma clearance of 99mTc-MAG3 (ClMAG) was calculated through early renal uptake of 99mTc-MAG3 after appropriate correction of parameters (background, measured attenuation coefficient of 99mTc, and the actual depth of kidneys measured with computed tomography), and on one-compartment assumption of the kinetics of 99mTc-MAG3. We compared the resultant ClMAG with standard effective renal plasma flow (ERPF), using the para-aminohippurate clearance method and with simulated ClMAG derived from the two-compartment model. RESULTS: ClMAG calculated by the one-compartment model (283+/-131 ml/min, mean +/- SD) correlated with ERPF (r = 0.94, p <0.001), and was similar to the simulated ClMAG estimated from the two-compartment model in all patients (283+/-139 ml/min). CONCLUSION: This alternative method, which employs theoretical modeling of the pharmacokinetics of 99mTc-MAG3, may provide easy, noninvasive measurement of individual renal function without blood sampling or in vitro equipment. Further studies should be warranted.

Computer Simulation↗
PubMed1998

[Clinical efficacy of MRCP for diagnosis of patients with pancreatic neoplasm].

We examined the usefulness of MRCP in pancreatic cancer compared with ERCP. Moreover, it examined in the same way in focal pancreatitis, too. We compare three findings of 1) main pancreatic duct, 2) branches of the stricture part, 3) side of tail main pancreatic duct about ERCP and MRCP. As for the branches of the stricture part, MRCP was poor compared with ERCP but as for the property of the side of the tail main pancreatic duct, MRCP excelled. The study of mass forming chronic pancreatitis was a similar result and was not the one, which excels ERCP in case of qualitative diagnosis. However, we thought that it was not invasively, suitable behind the digestive operation and digestive passage fault, in case of elapse observation and moreover that MRCP is suitable for pick up the pancreatic cancer in our clinic.

Adenocarcinoma↗
PubMed1997

Integrin alpha6 is involved in follicular growth in mice.

We previously reported that integrin alpha6 is expressed on granulosa cells in the inner layers of the human and porcine ovarian follicles, where granulosa cells have no direct contact with basal lamina. In this study, we examined the physiological role of integrin alpha6 on follicular growth with an immature superovulated mice model using the anti-integrin alpha6 monoclonal antibody, GoH3. In the ovaries of 9- to 20-day-old mice, integrin alpha6 was detected on all the layers of granulosa cells in the primordial, primary, and secondary follicles by immunohistochemistry. The 13-day-old female mice were superovulated by pregnant mare serum gonadotropin and human chorionic gonadotropin with the treatment of intraperitoneal administration of GoH3, or a control antibody, or PBS. In the group of GoH3 treatment, successful ovulation was observed in 57+/-25.7% of the animals, whereas no ovulation was observed in the control groups (p<0.01). These findings indicate that integrin alpha6 is involved in gonadotropin-induced follicular growth.

Animals↗
PubMed1997

Beta 2-integrin-mediated signal up-regulates counterreceptor ICAM-1 expression on human monocytic cell line THP-1 through tyrosine phosphorylation.

Intracellular cross-talk between LFA-1 and its counter receptor, intercellular adhesion molecule-1 (ICAM-1), on human monocytic cell line THP-1 was analyzed. Stimulation with mAb YH384 specific for LFA-1 alpha (CD11a) up-regulated ICAM-1 expression on THP-1 cells. Cell surface expression of ICAM-1 on THP-1 cells was dose-dependently up-regulated and reached the maximal level 24 hr after stimulation with mAb YH384. Up-regulation of ICAM-1 by mAb YH384 was further confirmed by Northern blotting analysis at the mRNA level, and the maximal message of ICAM-1 was observed 4 hr after stimulation. mAb YH384-induced upregulation of cell surface expression was ICAM-1-specific, and the expression of the other nine molecules tested was not augmented. Up-regulation of ICAM-1 was also observed following stimulation with other mAb specific for CD11a (S6F1), CD11b (JML-H11), and CD18 (IB4); all of these mAb recognized members of the beta 2-integrin family, but not with isotype-matched control mAb. The mAb 4B4 (specific for beta 1-integrin) similarly, but more weakly, augmented ICAM-1 expression. The effect of mAb YH384 on expression of ICAM-1 was dose-dependently suppressed by treatment with herbimycin A or genistein, both inhibitors of tyrosine kinase. These results suggest that beta 2-integrin-mediated up-regulation of ICAM-1 is mediated via a tyrosine phosphorylation pathway.

Animals↗
PubMed1997

Neuroprotective nitric oxide synthase inhibitor reduces intracellular calcium accumulation following transient global ischemia in the gerbil.

By observing the ultrastructural intracellular Ca2+ distribution with Ca(2+)-oxalate-pyroantimonate method, we examined whether the protective mechanism of the nitric oxide (NO) synthase inhibitor, N omega-nitro-L-arginine (LNNA), involves change of the intracellular Ca2+ movement in delayed neuronal death (DND) in gerbil hippocampal CA1 neurons following 5-min forebrain ischemia. In the group intraventricularly administered 5.0 mg/ml LNNA, 15 min after reperfusion the intracellular Ca2+ deposits and the mitochondrial Ca2+ uptake index increased to levels similar to those in the control group administered only artificial cerebro-spinal fluid, but by 180 min after reperfusion they had returned to the preischemic level. By 15 min after reperfusion Ca2+ deposits in the endoplasmic reticulum (ER) had almost disappeared in both groups, but at 180 min of reperfusion, the ER in only the LNNA group showed Ca2+ deposits. It is suggested that the neuronal toxicity of NO involves the dysfunction of the intracellular Ca2+ transport system including the mitochondria and ER.

Animals↗
PubMed1997

Parturition upregulates nitric oxide synthase activity in the rat anterior pituitary gland.

Recent evidence suggests that endogenous nitric oxide (NO) contributes to the modulation of hormonal secretion from the anterior pituitary gland according to the physiological state of the animal. In this study, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry and specific neurochemical assay were used to asses possible changes of NO synthase (NOS) activity in the anterior pituitary during pregnancy and parturition in rats. The anterior pituitary showed (weak) NADPH-d activity throughout pregnancy. Parturition increased the number and intensity of NADPH-d-positive cells. The NADPH-d-positive cells co-localized with immunofluorescent LH-positive cells. No variation in NADPH-d activity was apparent during the various stages of the oestrous cycle. Furthermore, NOS activity during parturition increased significantly when compared with non-pregnant and pregnant rats. Increases in both specific activity and NADPH-d activity gradually decreased within 24 h post-partum, suggesting that NO may modulate anterior pituitary function during parturition.

Animals↗
PubMed1997

Expression of a novel isoform of Vav, Vav-T, containing a single Src homology 3 domain in murine testicular germ cells.

Vav is a signal transducing molecule containing C-terminal Src homology 3 (SH3)-SH2-SH3 domains, and has been thought to be expressed exclusively in hematopoietic and trophoblastic cells. By Northern blot analysis, vav transcripts of unique sizes, 4.8 kb and 1.0 kb, were detected in the testis among various tissues examined. From a mouse spermatocyte cDNA library, a novel isoform of vav (vav-T) was cloned, which corresponded to a part of the 4.8 kb transcript. Vav-T had an alternative 5' sequence up to the middle of SH2-coding region, and encoded 163 amino acids with a single SH3 domain. Northern blot analysis of fractionated testicular cells and in situ hybridization histochemistry demonstrated that vav-T transcripts were expressed in the differentiating germ cells, especially spermatocytes. A 24 kD protein was detected by anti-Vav antibodies in the testis, but not in the spleen or bone marrow. Transcripts of heterogeneous nuclear ribonucleoprotein K, known to associate with the most C-terminal SH3 domain of Vav, were also detected in the differentiating male germ cells. These results demonstrate expression of previously nondescribed Vav-isoform in the testicular germ cells, and suggest that it interacts with RNA-binding proteins and plays an important role in spermatogenesis.

Amino Acid Sequence↗
PubMed1997

Coagulation patterns of disseminated intravascular coagulation in acute promyelocytic leukemia.

Coagulation patterns of 19 newly-diagnosed acute promyelocytic leukemia (APL) patients with disseminated intravascular coagulation (DIC) at presentation were studied. Seventeen patients had hemorrhagic complications, of which four were fatal. Fatal hemorrhages were related with lower fibrinogen level and lower platelet count. DIC of the APL patients without infection was characterized by low fibrinogen and normal antithrombin III (ATIII) level. Thrombin-ATIII complex level was elevated in all patients examined. Patients with infection had higher fibrinogen levels than those without infection and some patients had reduced ATIII level. Ten remission inductions were tried with multidrug chemotherapy and seven with all-trans retinoic acid (ATRA). Complete remission was achieved in seven of ten inductions with chemotherapy and in all seven inductions with ATRA. Two patients treated with chemotherapy had fatal hemorrhage after starting therapy but none treated with ATRA.

Adolescent↗
PubMed1997

Effects of severe global ischemia on N-acetylaspartate and other metabolites in the rat brain.

N-acetylaspartate (NAA) is found exclusively in neurons and their processes in the adult brain. Since the regional distribution of NAA may be imaged using magnetic resonance spectroscopic imaging (1H-MRSI), a regional measure of neuronal density may be noninvasively obtained. The technique may be particularly useful in the diagnosis of diseases where neurons are selectively injured, since these diseases do not result in definitive changes on conventional imaging studies. The goal of this study was to determine whether 1H-MRSI measurement of NAA defects neuronal loss following global ischemia. 1H-MRSI was performed in rats 24 h after global ischemia was induced by bilateral carotid occlusion plus hypotension. 1-H-MRSI showed that NAA was decreased by 28-74% in vulnerable regions, including the cortex, striatum, hippocampus, and, to a lesser extent, the thalamus. No change was observed in the brain stem or cerebellum. Regions where 1H-MRSI observed NAA was decreased also had histological evidence of selective neuronal necrosis and showed marked increase of lactate and alanine. These results show that 1H-MRSI detected loss of NAA in brain regions with selective neuronal loss, suggesting that 1H-MRSI measurements of NAA could detect neuronal loss in a variety of disease states where there is selective neuronal necrosis.

Alanine↗
PubMed1997

Combined hepatocellular carcinoma and cholangiocarcinoma in a mare.

A hepatic malignant tumour composed of both hepatocellular and cholangiocellular elements was studied histologically, immunohistochemically and electron microscopically in an 18-year-old Thoroughbred mare. Bile canaliculi and alpha-fetoprotein were useful in identifying the hepatocellular element, and mucin and keratin were good markers of biliary differentiation. The simultaneous presence of bile canaliculi and mucin-producing cells in most of the neoplastic lesions suggested that this tumour arose from a stem cell with capacity to differentiate into hepatocytes and biliary epithelium.

Animals↗