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Biomedical subjects

S Araki

Publications and source records attributed to S Araki.

At least 145 records · Page 8Linked to original sources
PubMed1997

Intracytoplasmic injection with late spermatids: a successful procedure in achieving childbirth for couples in which the male partner suffers from azoospermia due to deficient spermatogenesis.

OBJECTIVE: To investigate the feasibility of using late spermatids in intracytoplasmic sperm injection (ICSI) for patients in which there is a total lack of normal and testicular sperm. DESIGN: Clinical study. SETTING: Private fertility center with adjacent laboratory facilities. PATIENT(S): Thirty-six males diagnosed with azoospermia underwent testicular biopsy and the resulting spermatids from nine patients were used to fertilize oocytes retrieved from their respective wives by ICSI. INTERVENTION(S): Intracytoplasmic spermatid injection of oocytes with late spermatids obtained by testicular biopsy. MAIN OUTCOME MEASURE(S): Fertilization, pregnancy, and delivery rates. RESULT(S): Three of the cases resulted in pregnancies with childbirth occurring in all three, identical twins in one, and individual singletons in the other two cases. CONCLUSION(S): It is possible to achieve successful levels of pregnancy and childbirth in cases of azoospermia by intracytoplasmic injection of late spermatids.

Birth Weight↗
PubMed1997

Microalbuminuria is not associated with cardiovascular death in Japanese NIDDM.

To evaluate whether the presence of microalbuminuria can predict cardiovascular death in Japanese subjects with non-insulin-dependent diabetes mellitus (NIDDM), we investigated 297 Japanese NIDDM patients with Albustix-negative urine. Patients were divided into two groups, normoalbuminuric (n = 201) and microalbuminuric (n = 96) and followed until death or the end of 1994 (the mean follow-up period was 6.4 years). During the follow-up period, 28 deaths (14 normoalbuminuric and 14 microalbuminuric patients) were confirmed and only 10 deaths were attributed to cardiovascular disease (6 normoalbuminuric and 4 microalbuminuric patients). Although the age- and sex-adjusted mortality rate from all-causes in the microalbuminuric group was significantly higher than that in the normoalbuminuric group (13.5 vs. 8.2 per 1000 person-years: P < 0.05), the mortality rate from cardiovascular disease was not significantly different between two groups (3.4 vs. 3.3 per 1000 person-years). On age-adjusted Cox proportional hazards analysis. HbA1c and triglyceride were independent risk factors in mortality from cardiovascular disease, while microalbuminuria was not associated with cardiovascular death. These results indicate that, unlike Caucasians, the presence of microalbuminuria can not predict cardiovascular death in Japanese subjects with NIDDM.

Aged↗
PubMed1997

Cardiac and hemodynamic effects of TZC-5665, a novel pyridazinone derivative, and its metabolite in humans and dogs.

1. TZC-5665 is a novel pyridazinone derivative with vasodilatory and beta-adrenergic blocking activities and type III phosphodiesterase inhibitory action. 2. In healthy volunteers, TZC-5665 was rapidly absorbed and immediately metabolized. Its main metabolite, M-2, remained at a higher concentration in plasma. Orally administered TZC-5665 reduced end-diastolic left ventricular volume (20.16 ml) and exhibited a tendency to increase ejection fraction (0.04). 3. In dogs, M-2 dose-dependently increased cardiac contractility and reduced both preload and afterload. These effects appeared more potent in the failed heart than in the normal heart. At the same dose (30 micrograms/kg), the effects of M-2 seem to be more potent than those of milrinone. 4. We concluded that TZC-5665 is a useful medication for treating patients with chronic congestive heart failure (CHF) because of the positive inotropic and vasodilating effects due to its active metabolite in addition to its own beta-adrenergic blocking actions.

Adult↗
PubMed1997

Sleep development in children with congenital and acquired hypothyroidism.

To determine how thyroid hormone deficiency before birth influences early development of the human central nervous system, we examined sleep development in children with congenital hypothyroidism using all-night polysomnography. Although the sleep-wakefulness circadian rhythm was not disturbed, two patients under 1 year of age showed mild decreases of REM sleep. Rapid eye movements during REM sleep were significantly decreased in one patient in whom thyroxine replacement was delayed. Regarding phasic body movements during sleep, generalized gross movements were more frequently disturbed than localized muscle twitches, and even after L-thyroxine replacement, they were significantly reduced when compared with those in controls. Children with acquired hypothyroidism and neonatal transient hyperthyrotropinemia showed no severe abnormalities of the sleep parameters examined here. Sleep development in patients with congenital hypothyroidism is believed to be useful for regional evaluation of the brain impairment in congenital hypothyroidism.

Arousal↗
PubMed1997

Electrophysiological brainstem dysfunction in a child with Leigh disease.

We evaluated brainstem dysfunction in a girl with Leigh disease. Neuroradiological and neurophysiological tests included brain magnetic resonance imaging, [123I]IMP single-photon emission computed tomography (SPECT), auditory brainstem responses (ABRs), short-latency somatosensory evoked potentials (SSEPs), electrically elicited blink reflexes (BRs) and all night polysomnography (PSG). The basal ganglia and midbrain contained areas of low accumulation on [123I]IMP SPECT images. Serial analysis of ABRs and SSEPs showed progressive disturbances of the brainstem wave components. The R2 components of the BRs were impaired. All night PSG revealed disturbances in both the tonic and phasic components of REM sleep. These findings suggested the multimodality tests in combination with neuroradiologic examinations are useful for assessing brainstem dysfunction in patients with Leigh disease.

Blinking↗
PubMed1997

Overexpression of PRAD1/cyclin D1 in plasma cell leukemia with t(11;14)(q13;q32).

Two patients with plasma cell leukemia (PCL) with a t(11;14)(q13;q32) translocation are reported. Case 1 is a 64-year-old woman diagnosed as having primary PCL (IgA/lambda, Stage III) with high serum LDH and beta 2-microglobulin (beta 2MG) levels. She was treated with combination chemotherapy but died of gastrointestinal bleeding on the 45th hospital day. Case 2 is a 52-year-old man, initially diagnosed with multiple myeloma (IgG/kappa, Stage III) in August 1993. Relapse several months after primary chemotherapy was characterized by a rapid increase in plasma cells in peripheral blood, high serum LDH and beta 2MG levels, and resistance to further chemotherapy. Both cases showed complex karyotypic abnormalities including t(11;14), and Northern analysis revealed overexpression of the PRAD1/ cyclin D1 gene. The PRAD1 gene is found on chromosome band 11q13 and encodes cyclin D1. Cyclin D1 plays an important role in control of the cell cycle, and overexpression of PRAD1/cyclin D1 may be involved in disease progression in these cases.

Chromosomes, Human, Pair 11↗
PubMed1997

Efficacy of amino acid infusion for improving protein metabolism after surgery: a prospective randomized study in patients undergoing subtotal gastrectomy.

BACKGROUND: Appropriate regimens of peripheral parenteral nutrition (PPN) have been proposed for the improvement of protein metabolism after surgery. When evaluating the efficacy of administered nutrients, it is vital to consider the severity of surgical stresses to avoid confounding effects of the trauma on the postoperative metabolism. This study was designed to evaluate protein-sparing regimens through PPN in patients who had undergone subtotal gastrectomy. STUDY DESIGN: Patients hospitalized at our institutes for gastric cancer were randomly divided into the following five groups and received PPN for 7 days after surgery: 1. G group (n = 9), 200 g glucose (per day); 2. AG group (n = 10), 54 g amino acids + 150 g glucose; 3. AGG group (n = 9), AG + 110 g glucose; 4. AGF group (n = 10), AG + 40 g fat; and 5. AGL group (n = 7), 58 g amino acids + 60 g glycerol. Biochemical studies were done before and after surgery. RESULTS: In comparison to G group patients, AG group patients showed less negative cumulative nitrogen balances. No significant differences in cumulative nitrogen balances were observed between AGG, AGF, and AGL groups. Restoration of the reduced serum rapid turnover protein occurred earlier in the AGL group than in either the AGG or the AGF groups. Hyperglycemia, glucosuria, and hyperinsulinemia were prominent in the AGG group, and less prominent in the AGL group. Marked ketosis together with an increase in serum-free fatty acid levels was found in the AGL group. CONCLUSIONS: These results suggest that in patients who have undergone major elective surgery, infusion of amino acid solutions is advantageous for improving protein metabolism after surgery, and nonprotein energy source and intake are not essential when combined with amino acid solutions for improving nitrogen balance after surgery.

Adult↗
PubMed1997

Some properties of inorganic pyrophosphatase from Bacillus subtilis.

Inorganic pyrophosphatase (pyrophosphate phosphohydrolase, EC 3.6.1.1; PPase) from Bacillus subtilis was purified to a homogeneous state electrophoretically when analysed by SDS-PAGE. The enzyme consists of six identical subunits; the molecular weight of the native enzyme estimated by gel filtration was approx. 120,000, and denaturing polyacrylamide gel electrophoresis gave a single band corresponding to 24,000. The enzyme absolutely required a divalent cation for its activity. Mg2+ was most effective, showing two steps of concentration-dependent activation. Mg2+ could be partially replaced by Mn2+ and Co2+. The enzyme was thermostable in the presence of Mg2+, and no loss of activity was observed on the incubation at 55 degrees C for an hour.

Bacillus subtilis↗
PubMed1997

Case-control study of colorectal carcinoma in situ and cancer in relation to cigarette smoking and alcohol use (Japan).

A case-control study was performed in order to examine the relation of cigarette smoking and alcohol use to colorectal carcinoma in situ and cancer, separately. Study subjects consisted of 129 colorectal carcinoma in situ cases, 66 colorectal cancer cases, and 390 controls recruited from health check-up examinees in Tokyo from January 1991 to March 1993. Smoking status and alcohol habit were ascertained from a self-administered questionnaire. Both cumulative cigarette smoking and current smoking status were associated significantly with an increased risk of carcinoma in situ. A statistically nonsignificant increase in the risk of colorectal cancer was noted only among those with the heaviest exposure category of these measures of smoking. The cumulative exposure to cigarette smoking within recent 20 years was associated significantly with an increased risk of carcinoma in situ, whereas smoking until 20 years before the diagnosis was associated significantly with an increase of cancer risk. A significant and positive association was observed between cumulative alcohol drinking and colorectal cancer. These findings suggest that cigarette smoking may act as an initiator in colorectal carcinogenesis and also provide weak evidence that alcohol drinking is related to an increased risk of colorectal cancer.

Adenoma↗
PubMed1997

Endothelin-1 activates c-Jun NH2-terminal kinase in mesangial cells.

Endothelin-1 (ET-1) is known to induce the contraction and proliferation of glomerular mesangial cells. ET-1 has been shown to activate p42 and p44 mitogen-activated protein kinases (MAPKs), also known as extracellular signal regulated kinases (ERKs), through both protein kinase C (PKC) and protein tyrosine kinase (PTK)-dependent pathways. However, an involvement of c-Jun NH2-terminal kinase (JNK), one of members of the MAPK family, in ET-1 signaling in mesangial cells has not yet been elucidated. To clarify this point, we examined whether ET-1 could activate JNK and the mechanism of activation in cultured mesangial cells. ET-1 enhanced the activities of JNK in a dose-dependent (10(-8) M maximum) and time-dependent manner, with a peak at 15 minutes. ET-1-induced activation of JNK was blocked by BQ-123, an antagonist for the ETA receptor. The depletion of PKC by prolonged treatment with phorbol 12,13 dibutyrate or the inhibition of PKC by GF 109203X failed to inhibit ET-1-induced activation of JNK. In contrast, ET-1-induced activation of JNK was significantly reduced by calcium chelation (with BAPTA/AM and EGTA). In addition, ionomycin, a calcium ionophore, and thapsigargin, an intracellular calcium-rising agent, were able to induce the activation of JNK. ET-1-induced activation of JNK was also inhibited by PTK inhibitors (herbimycin A and genistein). Furthermore, ET-1 increased the DNA-binding activity of AP-1 containing c-Jun and c-Fos proteins. These results indicate that ET-1 is able to activate JNK in glomerular mesangial cells through PKC-independent and PTK-dependent pathways and intracellular calcium is necessary to the activation of JNK.

Animals↗
PubMed1997

Structural abnormalities of autosomal chromosomes in the male partner do not influence fertilization and early development of embryos after intracytoplasmic sperm injection.

The objective of this study was to determine whether or not abnormalities in the autosomal structure of the male partner have any influence on fertilization and early embryo development after intracytoplasmic sperm injection (ICSI). Thirty-seven couples in whom the male partners were examined by the same andrologist were included in this study. Six couples (group I) in whom the male partner possessed autosomal structural abnormality underwent seven ICSI cycles. As a control group, 31 couples (group II) in which the male partner was karyotypically normal underwent 41 ICSI cycles. Although the normal fertilization rates seen in group I were significantly higher than those in group II (P < 0.05), there was no significant difference in the cleavage rates between the two groups. We did not perform the analysis of the female partner's chromosomes, but we surmise that structural autosomal abnormalities in the male partner do not adversely influence fertilization at ICSI and early development of embryos.

Adult↗
PubMed1997

Inhibitors of phospholipase promote apoptosis of human endothelial cells.

In order to understand the signal transduction system that regulates apoptosis of human umbilical vein endothelial cells (HUVEC), we investigated the effects of inhibitors of the activity of phospholipases. All three tested inhibitors of phospholipase A2 (PLA2), namely, manoalide, 3-(4-octadecyl)benzoylacrylic acid (OBAA), and oleyoxyethylphosphorylcholine (OOPC), induced apoptotic cell death of HUVEC. After 16 h of treatment, almost all of the cells had disintegrated into apoptotic bodies, and DNA ladders characteristic of apoptotic cell death were clearly observed upon analysis of DNA on agarose gels. The release of arachidonic acid from the cells that had been treated with manoalide, OBAA or OOPC (at the same concentrations as those at which these compounds induced apoptosis) was inhibited. We also studied the effects of two inhibitors of phosphatidylinositol-specific phospholipase C (PLC), U73122, and compound 48/80. Both compounds promoted the apoptosis of HUVEC. After 16 h of treatment, few cells remained intact, and DNA fragmentation was clearly detectable after only 12 h. Quantitation of inositol released from cells treated with U73122 and compound 48/80 showed that the release of inositol was blocked. By contrast, U73343, a similar aminosteroid that does not inactivate PLC, had no such effects. Our results suggest that PLA2 and phosphatidylinositol-specific PLC might be involved in the signaling pathway of apoptosis in HUVEC, and that the metabolism of arachidonic acid and of inositol might play important roles in the present apoptotic signal-transduction system.

Apoptosis↗
PubMed1997

Decreased cytotoxic lymphocyte counts in alexithymia.

BACKGROUND: Alexithymia is a psychological trait characterized by a difficulty in verbalizing feelings, which has been associated with a number of illnesses, including bronchial asthma and cancer. METHODS: In order to understand how psychological variables such as alexithymia affect physical health, we compared the lymphocyte subsets of men (n = 97, mean 30.6) rated as high and low alexithymic when measured by the Toronto Alexithymia Scale (TAS). We analyzed our data by considering alexithymia a categorical variable, using TAS scores of 62 and below, and 74 and above, and by considering alexithymia a continuous variable, using the mean TAS score (64.01) separating high from low alexithymia. RESULTS: When alexithymia was considered a categorical variable, highly alexithymic men had significantly lower numbers of the most cytotoxic natural killer (NK) subset, (CD57-CD16+ cells). When alexithymia was considered a continuous variable, in addition to the NK subset, killer effector T cell (CD8+CD11a+ cells) count was also significantly lower. These results were obtained after controlling for possible effects of smoking and alcohol intake. CONCLUSIONS: These results suggest that the negative modulation of cellular immunity, especially the cytotoxic lymphocytes, may be one mechanism which, combined with other factors that have a negative effect on the immune system such as stress, results in the association between alexithymia and ill health. It is suggested that future studies should, in addition to cell counts, attempt to identify the effects of psychological variables on the cytolytic activity of cytotoxic lymphocytes. Furthermore, follow-up studies should monitor the subjects over the years to demonstrate that alexithymia-mediated negative modulation of the immune system results in clinical pathologies.

Adult↗
PubMed1997

Effects of job strain on helper-inducer (CD4+CD29+) and suppressor-inducer (CD4+CD45RA+) T cells in Japanese blue-collar workers.

BACKGROUND: The effects of job strain on helper-inducer (CD4+CD29+) T cells and suppressor-inducer (CD4+CD45RA+) T cells are not clear. METHODS: The subjects were 65 male blue-collar workers in a chemical plant in Japan. Perceived job stressors were assessed using the Japanese version of Job Content Questionnaire, i.e., job demands, job control, supervisor support and coworker support. Blood samples were taken from these subjects, and number and percentage of total lymphocytes were calculated for total T cells, helper (CD4+) T cells, suppressor/cytotoxic (CD8+) T cells, helper-inducer (CD4+CD29+) T cells and suppressor-inducer (CD4+CD45RA+) T cells using the double-staining fluorescence. RESULTS: Job control significantly and positively correlated with number and percentage of helper-inducer (CD4+CD29+) T cells, after controlling for age, number of cigarettes per day and blood lead concentration (Spearman's partial correlation, p < 0.05), while job demands, supervisor support or coworker support did not (p > 0.05). The job strain index, i.e., the ratio of job demands to job control, significantly and negatively correlated with the percentage of helper-inducer (CD4+CD29+) T cells (p < 0.05). None of the job stress scales significantly correlated with number or percentage of suppressor-inducer (CD4+CD45RA+) T cells (p > 0.05). CONCLUSIONS: It is suggested that higher job strain or lower job control is associated with a decrease in helper-inducer (CD4+CD29+) T cells in Japanese blue-collar workers.

Adult↗
PubMed1997

Neurotropic pyrimidine heterocyclic compounds. II. Effects of novel neurotropic pyrimidine derivatives on astrocytic morphological differentiation.

Astrocytes play an important role in supporting nerve regeneration after brain injuries. In this study, the effects of novel neurotropic synthesized pyrimidine compounds on astrocytic morphological differentiation were examined. Treatment of protoplasmic cultured astrocytes with 2-piperidino-5,6-dihydro-7-methyl-6-oxo(7 H)pyrrolo[2,3-d]pyrimidine maleate (MS-430) and the related compounds caused astrocytic process formation in 60 min. The morphology of MS-430-treated cells was similar to that of dibutyryl cAMP (DBcAMP)-treated cells. The astrocytic process formation by MS-430 was observed within 60 min and the maximum effect was obtained at the drug concentration of 0.5-1.0 mM. Rhodamine-phalloidin staining showed that astrocytic cytoskeletal actin was reorganized by MS-430 and DBcAMP. MS-430 did not increase cAMP accumulation in cultured astrocytes. These results suggest that the neurotropic pyrimidines induced astrocytic morphological differentiation through a cAMP-independent mechanism.

Animals↗