Biomedical subjects

T Ishiguro

Publications and source records attributed to T Ishiguro.

At least 109 records · Page 6Linked to original sources

PubMed1995

Renal dopaminergic activity in patients with primary aldosteronism.

To clarify the role of renal dopaminergic activity in patients with primary aldosteronism (PA), urinary excretion of free dopamine (DA) and the conversion ratio of DA from l-dopa in the kidney were investigated in 8 patients with PA and 10 normotensive subjects (NT). All subjects were hospitalized and received a standard diet (Na 120 mEq, K 75 mEq/day) and 2 h renal clearance test was performed. Plasma l-dopa concentration (p-DOPA), creatinine clearance (Ccr), urinary excretion of sodium (UNaV) and DA (uDA) as well as fractional excretion of sodium (FENa) were measured. No significant difference was found in UNaV or FENa between NT and PA, or between before and after adrenalectomy (Adx) in PA. UDA was significantly higher in PA than NT, and decreased significantly after Adx. There was no difference in the product of Ccr X p-DOPA between NT and PA, or between before and after Adx in PA. The ratio of uDA/(Ccr X p-DOPA) was significantly higher in PA than NT. After Adx this ratio decreased significantly to the normal range. These results suggest that (1) renal dopaminergic activity is augmented and contributes to the escape phenomenon in PA, and (2) augmented renal DA production in PA might be caused by an increase of conversion to DA from l-dopa at the renal proximal tubules.

Adenoma↗

PubMed1995

The role of renal natriuretic depressor systems on hypertensive mechanisms in reduced renal mass hypertensive rats.

The pathophysiological role of renal natriuretic depressor systems and endogenous digitalis like factor (EDLF) on blood pressure (BP) elevation was studied in reduced renal mass rats (RRM) with saline loading for a model of volume dependent hypertension. Fifty-four male Sprague-Dawley rats were operated on to remove varying proportions of their kidney mass (5/6 RRM, n = 13; 4/6 RRM, n = 16; 3/6 RRM, n = 12) or sham operated (control, n = 13). They were given 1% saline to drink for 4 weeks. BP was elevated significantly at the 1st week in 5/6 RRM and continued to increase until the 4th week, but this was not seen in the other 3 groups. Urine volume (UV) and urinary sodium excretion (UNaV) increased after saline loading in all groups. Urinary kallikrein excretion was significantly lower in order of the 5/6, 4/6 and 3/6 RRM at the basal state and after saline loading. A significant negative correlation was observed between urinary kallikrein and BP. Urinary PGE2 was increased in each RRM in order of the 5/6, 4/6 and 3/6 RRM groups. A significant positive correlation was observed between urinary PGE2 and BP, UV or UNaV. The basal urinary DA excretion was significantly lower in 3 RRMs than in the control. After saline drinking, urinary DA increased in 3 RRMs, while differences disappeared in the control and RRMs. Urinary EDLF increased immediately after the initiation of saline loading in all groups, except the control group, and returned to the basal level 2 weeks later in 3/6 and 4/6 RRM. Only in 5/6 RRM, the urinary EDLF remained higher than the basal level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

The pathophysiological role of renal dopamine and kallikrein in deoxycorticosterone acetate (DOCA)-salt treated rats.

To elucidate the pathophysiological role of the renal dopamine (DA) and kallikrein-kinin systems in volume dependent hypertension under excess mineralocorticoid, the urinary excretions of DA and kallikrein (KAL) were investigated in DOCA-salt treated rats (5 week-old Sprague-Dawley rats, DOCA 100mg pellet, s.c., 1% saline ingestion for 4 weeks, n = 7) for comparison with those of control rats (vehicle, 1% saline ingestion for 4 weeks, n = 10). In vehicle, systolic blood pressure (SBP), urinary excretion of free DA (UDA) and kallikrein (UKAL) did not change through the study. In DOCA treated rats, marked natriuresis was observed with sodium load. SBP and UKAL significantly increased at the 4th week and at the 2nd week, respectively. UDA increased significantly to the peak level at the 1st week, and then decreased gradually. At the 4th week, UDA was significantly lower in DOCA-treated rats than that of vehicle rats. A significant inverse correlation was found between UDA and SBP, and UKAL correlated positively with SBP and urinary excretion of sodium and negatively with UDA in DOCA treated rats. These results suggest that the augmentation of renal dopaminergic activity which may in part cause sodium escape appears at the early stage of DOCA-salt treatment, but this augmentation is subsequently blunted; volume and sodium retention may be associated with the blood pressure elevation at the late stage of DOCA-salt treatment, and that the augmentation of renal kallikrein-kinin system may be a compensatory response to sodium and volume retention in DOCA-salt treated rats.

Animals↗

PubMed1995

Spontaneous recurrence of methamphetamine psychosis: process and monoamine neurotransmitter function.

We studied the process that causes a spontaneous recurrence of methamphetamine (MAP) psychosis, a phenomenon known as flashbacks, in 41 female flashbackers by a comparison of clinical characteristics between the 41 flashbackers and 87 non-flashbackers with previous MAP psychosis. We evaluated plasma levels of monoamine metabolites in 25 of the 41 flashbackers, 19 of the 87 non-flashbackers, 9 female patients with persistent MAP psychosis and 61 physically healthy female controls. All 41 flashbackers had experienced a significantly greater frequency of threatening events and threatening paranoid-hallucinatory states than the 87 non-flashbackers during previous MAP abuse. The triggering factor was a mild fear of other persons due to the evocation of frightening images, encoded through threatening experiences during previous MAP abuse. Norepinephrine (NE) levels were significantly associated with a history of flashbacks. Plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels were significantly higher during flashbacks and during periods of normalcy in the flashbackers, and in the non-flashbackers, than MHPG levels in the user controls. NE levels in the patients with persistent MAP psychosis were also significantly higher than NE levels in the user controls. Elevated NE levels in the flashbackers were associated with disrupted NE, 5-HT and DA turnover. Thus, MAP-induced sensitization to frightening images may have caused the flashbacks due to aggravated noradrenergic hyperactivity.

Adult↗

PubMed1995

[Coronary risk index for pre-operative evaluation of ischemic heart disease].

The incidence of ischemic heart disease is increasing in Japan, and we often experience perioperative management of patients with coronary arterial stenosis. It is, however, difficult to evaluate the lesion of coronary arterial stenosis. We devised a coronary risk index (CRI), which is a scoring system and can easily predict the coronary arterial stenosis from the preoperative routine examination and the patients data. The patients with high CRI have a high risk of ischemic heart disease. By carefully managing these patients from this information, we can decrease the incidence of perioperative complications resulting from ischemic heart disease.

Adult↗

PubMed1994

Intratumoral DNA heterogeneity correlated with lymph node involvement and surgical staging in epithelial ovarian cancer by flow cytometry.

BACKGROUND: Flow cytometry (FCM)-measured DNA content may be a predictor in the prognosis of ovarian cancer. Multiple specimens taken from the same ovarian tumor may show a variation in DNA content (i.e., intratumoral DNA heterogeneity). We measured the FCM DNA content of multiple specimens from the same tumor in ovarian cancer, and the relationship among DNA ploidy, intratumoral DNA heterogeneity, retroperitoneal lymph node involvement, and surgical staging was evaluated. METHODS: Forty-one patients with primary epithelial ovarian cancer were included in the study. The FCM-measured DNA content of multiple fresh tumor specimens taken from different parts of the same ovarian tumor from each patient was measured. When aneuploidy was observed in at least one specimen from the same tumor, the tumor was defined as an aneuploid tumor. If there were two or more different aneuploid stem lines with a variation of DNA indices (differences of the DNA indices > 0.15) from the same tumor, the presence of intratumoral DNA heterogeneity was defined. RESULTS: Diploid tumor was found in 8 (19.5%) of the 41 patients, and aneuploid tumor with intratumoral DNA heterogeneity was found in 20 (48.8%). None of the eight patients with diploid tumors demonstrated lymph node involvement. In contrast, lymph node involvement was found in 14 (70.0%) of 20 patients with intratumoral DNA heterogeneity. There was a significant different incidence of lymph node involvement between the groups with and without intratumoral DNA heterogeneity (P < 0.01). The incidence of intratumoral DNA heterogeneity significantly correlated with the International Federation of Gynecology and Obstetrics staging (P < 0.01), while that of aneuploid tumor did not. CONCLUSIONS: Intratumoral DNA heterogeneity reflected a malignant potential for lymph node involvement and its progression in epithelial ovarian cancer.

Aneuploidy↗

PubMed1994

Single photon emission computed tomography with 123I-IMP in three cases of the neuroleptic malignant syndrome.

Single photon emission computed tomography (SPECT) perfusion brain scans using 123I-N-isopropyl-p-iodoamphetamine (123I-IMP) were performed in three patients with the neuroleptic malignant syndrome (NMS). In two accumulation was increased in the left basal ganglia and decreased in the right on the early images during the active phase of NMS; this asymmetry was not seen after recovery. In the third patient two examinations were performed during the active phase; on the first, increased accumulation of 123I-IMP in the left basal ganglia was found on the early images, but on the second, increased accumulation of tracer was found in the right basal ganglia on the delayed images. These abnormalities disappeared after improvement of the NMS. These results suggest that a disturbance in the basal ganglia is related to the development of NMS.

Adult↗

PubMed1994

CNS regulation of blood lactate concentration in anesthetized rats.

This study evaluated the effect of stimulating the central nervous system (CNS) with neostigmine, an inhibitor of acetylcholinesterase, on the blood lactate concentration in fed rats and in rats fasted for 48 hours. After the rat was anesthetized with pentobarbital, neostigmine was stereotaxically injected into the third cerebral ventricle. In fed rats, the central injection of neostigmine significantly increased the blood lactate level, while concomitantly increasing plasma glucagon, epinephrine and norepinephrine concentrations. Constant infusion of somatostatin throughout the experiments, to inhibit glucagon secretion from the pancreas, did not affect alterations in blood lactate by central injection of neostigmine. In adreno-medullated rats, CNS-stimulation by neostigmine still increased plasma norepinephrine significantly, however, the alteration in blood lactate was only one-third of that in intact rats. Intraperitoneal propranolol, but not phentolamine, prevented the rise in lactate. Neostigmine increased lactate in fasted rats as well as in fed rats. We conclude that in anesthetized rats, stimulation of the CNS by neostigmine increases blood lactate mainly through circulating epinephrine and partially through circulating norepinephrine or direct sympathetic nervous stimulation; glucagon does not appear to be involved in the increase in blood lactate.

Anesthesia, General↗

PubMed1994

Combined intrauterine and ovarian pregnancy: a case report.

A case of combined intrauterine and ovarian pregnancy diagnosed by postoperative microscopic observations is reported in this paper. The patient was a 23-year-old, Japanese nulligravid female. On the 32 day after a previous D & C when normal chorionic tissues of very early gestation were obtained, she complained of severe lower abdominal pain. Immediate laparotomy revealed hemorrhaging from a hematoma-like region on the surface of the left ovary, and partial resection of the left ovary was performed. The resected ovary was composed of an intact corpus luteum and another thin corpus luteum around a hematoma-like region containing chorionic villi, confirming this case to be an ovarian pregnancy. Histological findings of chorionic villi of the ovary indicated that ovarian pregnancy took place during the same menstrual period as intrauterine pregnancy, and not after the prior D & C. From these observations, this case was diagnosed as a combined intrauterine and ovarian pregnancy.

Abortion, Induced↗

PubMed1994

Clinical significance of serum alpha-fetoprotein subfractionation in pediatric diseases.

Serum alpha-fetoprotein (AFP) subfraction profile is a predictive indicator for the discrimination of hepatic malignancies, benign liver diseases and yolk sac tumor in adults. In the present study, AFP subfractions were examined in AFP-positive sera from 59 patients of less than 15 years of age. Fractionation of AFP was carried out by lectin affinity crossed-line immunoelectrophoresis. Concanavalin A, Lens culinaris hemagglutinin and phytohemagglutinin E were used as lectins. Fifty-four of 59 (91.5%) AFP subfraction profiles in patients with pediatric diseases were classified into three common types: (1) benign liver disorder, (2) hepatic malignancy and (3) yolk sac tumor. An atypical AFP subfraction profile resembling hepatic malignancy type was found in 5 of 59 (8.5%) infants. It was concluded that estimation of serum AFP subfraction profiles facilitates differential diagnosis of various AFP-positive pediatric diseases, such as hepatoblastoma, hepatoma, hepatic cirrhosis, hepatitis or germ cell tumors.

Adolescent↗

PubMed1994

[Risk factors for retroperitoneal lymph node metastasis in ovarian cancer].

The incidence and significant risk factors for retroperitoneal lymph node metastasis were investigated in 48 patients with primary epithelial ovarian cancer. Twenty-four (50.0%) of the 48 patients had para-aortic and/or pelvic lymph node metastases. In retroperitoneal lymphadenectomy at primary cytoreductive surgery, all patients with lymph node metastases were found to have both para-aortic and pelvic lymph node metastases. It is possible that the lymphatic extension, from the pelvic lymph node to the para-aortic lymph node, is one of the routes of retroperitoneal lymph node metastases in primary epithelial ovarian cancer. The incidence of lymph node metastases significantly increased with the spread of the abdominal tumor, peritoneal cytology, peritoneal metastasis, omental metastasis, involvement of both ovaries and poor histological grade. In the multiple analysis, the spread of the abdominal tumor, positive peritoneal cytology and poor histological grade were found to be the most important risk factors for retroperitoneal lymph node metastasis in ovarian cancer.

Cystadenocarcinoma, Serous↗

PubMed1993

Does dantrolene influence central dopamine and serotonin metabolism in the neuroleptic malignant syndrome? A retrospective study.

Homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) levels in the cerebrospinal fluid (CSF) were determined twice in nine cases of neuroleptic malignant syndrome (NMS) during the active phase. During the test period, three cases received no dantrolene and six cases received dantrolene prior to the second CSF examination. In the group not administered dantrolene, the levels of HVA and 5-HIAA were lower on the second examination compared to the first, suggesting that the levels of these substances decreased during the course of NMS. In the group receiving dantrolene, the levels of HVA and 5-HIAA increased after administration compared with the preadministration levels. In particular, a significant difference in the changes in HVA was demonstrated between the two groups. This suggests that dantrolene influences central dopaminergic metabolism in the active phase of NMS.

Adult↗

PubMed1993

Comparative study of human and rabbit cell infection with cell-free HTLV-I.

Infection of human and rabbit cells with cell-free HTLV-I was studied by PCR analysis. Both human and rabbit PBL were infected similarly by cell-free virus of both human and rabbit cell origin. Cells were infected with the cell-free virus without prior treatment and regardless of the concentration of the culture supernatant containing the virus. Human and rabbit cell lines were also infected similarly by the cell-free virus, the proviral DNA persisting for more than two months. The culture supernatants of HTLV-I-producing cells could thus be a potential cause of laboratory infections.

Animals↗

PubMed1993

Plasma noradrenaline as an indicator of functional state in hearts with mitral stenosis: the influence of acutely reduced left atrial pressure by balloon mitral commissurotomy.

To investigate the mechanism in which plasma noradrenaline concentration (pNA) is elevated in heart failure, the effect of balloon mitral valvuloplasty was used as a model of acute manipulation of the left atrial pressure reduction in ten patients with mitral stenosis. Gorlin mitral valve area and pNA were correlated with New York Heart Association functional class and found to have a significant exponential inverse relationship with each other ([pNA, pg/ml] = 198.9 x [mitral valve area, cm2]-0.696; P = 0.003). Elevated pNA could be partially explained by a reduced cardiac index (CI) ([pNA, pg/ml] = 403.4 x [CI, l/min/m2]-0.889; P = 0.027; r = 0.495), especially in severely failed hearts, but not by pulmonary capillary wedge pressure (PCWP). However, the percent changes (% delta) of variables early after balloon valvuloplasty exhibited a paradoxical contrast; % delta pNA showing a clear negative exponential correlation with % delta PCWP ([% delta pNA] = 436.0 x [% delta PCWP + 80]-0.679 - 80; P = 0.021), but not with % delta CI. These results suggest that pNA should be considered an indicator of cardiac functional class in mitral stenosis. PNA is modulated by both cardiac index and pulmonary capillary pressure, but in different ways.

Adult↗

PubMed1993

First clinical application of an automatic VA-ECMO system using artificial hearts as a blood pump.

A new extracorporeal membrane oxygenation (ECMO) circuit using air-driven artificial hearts as a blood pump was first applied on a newborn with congenital diaphragmatic hernia. ECMO was continued for 67 hours 36 minutes with no mechanical trouble. Since the artificial hearts changed their output automatically in proportion to venous return and did not generate excessive negative and excessive positive pressure, the automatic ECMO circuit could be handled safely by a small number of less-skilled staff.

Extracorporeal Membrane Oxygenation↗

PubMed1993

Immunohistochemical type distinction of alpha-fetoprotein in various alpha-fetoprotein-secreting tumors.

In order to clarify the histogenesis of alpha-fetoprotein (AFP)-secreting tumor tissues, formalin-fixed, paraffin-embedded serial sections of 148 tumors in various organs were examined by the peroxidase-antiperoxidase method for AFP, and paradoxical concanavalin A staining. Yolk sac-type AFP was found in yolk sac tumors, embryonal carcinomas, solid teratomas, (yolk sac) endodermal cell tumors, adenocarcinomas (stomach, ovary or lung) and metastatic liver cancers. Hepatic-type AFP was demonstrated in hepatocellular carcinomas, hepatoblastomas, solid teratomas and a stomach cancer. Yolk sac-type AFP was observed in the neighboring liver cells of metastatic liver cancers without relation to the type of AFP in primary cancers. The results from serum analyses of preoperative tumor-bearing patients (68 cases) were coincident with those from immunohistochemical stainings.

Female↗

PubMed1993

Cardiopulmonary effects of a combination of medetomidine and butorphanol in atropinized pigs.

Cardiopulmonary effects of a combination of medetomidine and butorphanol were evaluated in atropinized pigs. This combination unchanged the cardiac output and significantly lowered the oxygen consumption compared with base-line values. Although some statistically significant changes were recorded, both medetomidine and butorphanol did not have a marked effect on the cardiopulmonary parameters in atropinized pigs. It was indicated that the administration of the combination of medetomidine and butorphanol is relatively safe in atropinized pigs.

Adrenergic alpha-Agonists↗

PubMed1993

[A study of clinical pictures and monoamine metabolism of Gilles de la Tourette syndrome].

Gilles de la Tourette Syndrome (Tourette syndrome) is a movement disorder characterised by both motor and vocal (phonic) tics, accompanied by coprolalia and frequently echolalia. Since Seignot discovered that administration of haloperidol (HPL) was effective in treating Tourette syndrome, the etiology of this syndrome has been hypothesized as abnormal metabolism in neurotransmitters. We studied the clinical pictures on nine typical cases of Tourette syndrome and measured the HVA, MHPG, and 5-HIAA in their cerebrospinal fluid (CSF). Diagnosis of Tourette syndrome were made of the nine cases (all males) by DSM-III-R. All cases had symptoms of either coprolalia or echolalia. Four cases had no history of treatment with neuroleptics (untreated group) and five cases were under treatment with HPL (treated group). CSF was obtained from each subject in the morning (between 9:00-9:30 a.m.), at rest with nothing by mouth since last night and it was rapidly frozen and stored at -80 degrees C. HVA, the metabolite of dopamine, MHPG, the metabolite of norepinephrine, and 5-HIAA, the metabolite of serotonin, were analyzed by HPLC. The same analyses were made in five males who were healthy volunteer controls (control group). Comparisons were made of the HVA, MHPG and 5-HIAA levels between the three groups (untreated, treated and control group). HVA was 63.5 +/- 8.4 ng/ml in the untreated group, which was significantly higher than the 35.6 +/- 8.6 ng/ml in the controls (p < 0.05). No significant difference was found in both MHPG and 5-HIAA between the untreated and control group. No significant differences were found in HVA or MHPG between the treated group and the controls. The treated group had significantly lower 5-HIAA levels than the controls (p < 0.05). A significantly lower levels of CSF HVA were found in the treated group than in the untreated group (p < 0.05), but there were no significant differences in MHPG or 5-HIAA in the treated and untreated group. Assuming that the untreated group was most indicative of Tourette syndrome during the study, higher levels of HVA may indicate dopaminergic hyperfunction.

Adolescent↗