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Biomedical subjects

T Goto

Publications and source records attributed to T Goto.

At least 559 records · Page 31Linked to original sources
PubMed1992

Response of pontomedullary reticulospinal neurons to vestibular stimuli in vertical planes. Role in vertical vestibulospinal reflexes of the decerebrate cat.

1. To investigate the neural substrate of vestibulospinal reflexes in decerebrate cats, we studied the responses of pontomedullary reticulospinal neurons to natural stimulation of the labyrinth in vertical planes. Our principal aim was to determine whether reticulospinal neurons that terminate in, or are likely to give off collaterals to, the upper cervical segments had properties similar to those of the vestibulocollic reflex (VCR). 2. Antidromic stimulation was used to determine whether the neurons projected to the neck, lower cervical, thoracic, or lumbar levels. Dynamics of the responses of spontaneously firing neurons were studied with sinusoidal stimuli delivered at 0.05-1 Hz and aligned to the plane of body rotation, that produced maximal modulation of the neuron (response vector orientation). Each neuron was assigned a vestibular input classification of otolith, vertical canal, otolith + canal, or spatial-temporal convergence (STC). 3. We found, in agreement with previous studies, that the largest fraction of pontomedullary reticulospinal neurons projected to the lumbar cord, and that only a small number ended in the neck segments. Neurons projecting to all levels of the spinal cord had similar responses to labyrinth stimulation. 4. Reticulospinal neurons that received only vertical canal inputs were rare (1 of 67 units). Most reticulospinal neurons (48%) received predominant otolith inputs, 18% received otolith + canal input, and only 9% had STC behavior. These data are in sharp contrast to the results of our previous studies of vestibulospinal neurons. A considerable portion of vestibulospinal neurons receives vertical canal input (38%), fewer receive predominantly otolith input (22%), whereas the proportion that have otolith + canal input or STC behavior is similar to our present reticulospinal data. 5. The response vector orientations of our reticulospinal neurons, particularly those with canal inputs (canal, otolith + canal, STC) were predominantly in the roll quadrants. There was no evidence of convergence of inputs from like canals across the midline (e.g., right anterior + left anterior). 6. Two characteristics of the VCR, STC behavior and bilateral input from symmetric vertical canals (in some muscles), cannot be accounted for by the reticulospinal neurons that we studied. Because these characteristics are also not seen in vestibulocollic neurons, they are likely to be the result of the appropriate convergence of vestibular signals in the spinal cord. 7. Pontomedullary reticulospinal neurons seem particularly well suited to play a role in gravity-dependent postural reflexes of neck and limbs.

Acoustic Stimulation↗
PubMed1992

Connections between utricular nerve and dorsal neck motoneurons of the decerebrate cat.

1. We studied connections between the utricular (UT) nerve and dorsal neck motoneurons in decerebrate cats. Electrodes were fixed in place on the UT nerve under visual observation; the other branches of the vestibular nerve were transected. 2. The N1 field potential evoked by UT nerve stimulation was recorded in the vestibular nuclei at the start of each experiment. The potential typically grew until it reached a plateau. Stimulus spread (if any) to the central ends of other nerve branches was revealed by an additional increase in N1 amplitude after the plateau was reached. 3. We recorded intracellularly from 55 motoneurons in C1-C3. Some were identified as having axons in the dorsal rami, which innervate dorsal neck muscles. Others projected in nerves that were not available for stimulation. 4. UT nerve stimulation evoked synaptic potentials in essentially all motoneurons studied. The predominant pattern consisted of disynaptic excitatory postsynaptic potentials in ipsilateral motoneurons and inhibitory postsynaptic potentials that were at least trisynaptic in contralateral motoneurons. 5. The results demonstrate the presence of short-latency connections between the utricular nerve and dorsal neck motoneurons. The functional role of this pathway remains to be investigated.

Animals↗
PubMed1992

Comparison of lipids, apoproteins and associated enzyme activities between diabetic and nondiabetic end-stage renal disease.

Lipids, apoproteins and associated enzyme activities in type 2 diabetic end-stage renal disease (ESRD) were compared with that in nondiabetic ESRD and normal controls. Of the 40 uremic patients with non-insulin-dependent diabetes mellitus, 20 patients were receiving stable continuous hemodialysis treatment (CHT). Of the 39 patients with nondiabetic ESRD, 21 were undergoing CHT. Patients with nondiabetic ESRD exhibited elevated levels of serum triglyceride and a marked reduction in high-density-lipoprotein (HDL) cholesterol. Concentrations of serum apolipoprotein (Apo) C-3 were higher than in controls, whereas mean levels of serum Apo E were lower. The concentrations of serum Apo A-1 and Apo A-2 decreased with diminished lecithin: cholesterol acyltransferase activity. Lipoprotein lipase activity decreased in undialysed patients, and hepatic triglyceride lipase activity decreased significantly throughout the observation. Patients with diabetic ESRD exhibited elevated serum Apo B and normal serum Apo E levels, besides the lipid and Apo abnormalities observed in nondiabetic ESRD. Moreover, a prominent reduction in serum Apo A-1 was found in dialysed diabetic patients. The Apo B/Apo A-1 ratio was significantly higher in diabetic ESRD than in nondiabetic patients undergoing CHT. These results indicate that lipid abnormalities are accelerated in diabetic ESRD and may constitute a serious risk for the development of atherosclerosis.

Adult↗
PubMed1992

Cytogenetics of tumor cells from patients with nonfamilial renal cell carcinomas.

We analyzed cytogenetically 20 nonfamilial renal cell carcinomas, using a combined method of enzymatic technique and short-term culture with several passages. From 16 of the 20 patients, metaphase cells suitable for analysis were successfully obtained. Fourteen of the 16 patients demonstrated clonal chromosome aberrations which included missing Y chromosome in 8, gain of chromosome 7 in 7, an extra X chromosome in 4, translocation between chromosome 3 and other chromosomes in 4, deletion of the short arm of chromosome 3 in 2 and monosomy 3 in 2. Abnormalities of chromosome 7 and sex chromosomes were only numerical, and those are thought to be related to the neoplastic changes of various malignant tumors. Abnormalities of chromosome 3, however, were not only numerical but also structural, especially in the short arm, and those may be possibly associated with the genesis of renal cell carcinoma.

Adult↗
PubMed1992

Single-dose kinetics of primidone in human subjects: effect of phenytoin on formation and elimination of active metabolites of primidone, phenobarbital and phenylethylmalonamide.

Effect of repetitive administration of phenytoin (PHT) on the single-dose pharmacokinetics of primidone (PRM) was investigated in 3 healthy male subjects. The peak concentration of unchanged PRM was achieved at 12 and 8 h after the administration of PRM in the absence and the presence of PHT, respectively. The elimination half-life of PRM was decreased from 19.4 +/- 2.2 (mean +/- S.E.) to 10.2 +/- 5.1 h (p < 0.05) and the total body clearance was increased from 24.6 +/- 3.1 to 45.1 +/- 5.1 ml/h/kg (p < 0.01) in the presence of PHT. No significant change was observed for the apparent volume of distribution between the two treatments. In the absence of PHT, the measurable amount (> or = 0.1 mumol/l) of phenobarbital (PB) and phenylethylmalonamide (PEMA) did not appear in the serum until 5.3 and 1.3 h after the PRM administration, and the peak concentrations of PB and PEMA were achieved at 52 and 36 h, but the concentrations of both metabolites were very low (PB 1.3 mumol/l; PEMA 1.7 mumol/l). In the presence of PHT, within 0.8 and 0.5 h after the administration of PRM, the derived PB and PEMA appeared in the serum. About a 6-fold increase in the peak concentrations of both the metabolites were observed (PB 8.2 mumol/l; PEMA 11.0 mumol/l). No significant changes were observed for the elimination half-lives of both PB and PEMA in the absence and presence of PHT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Nocturnal blood pressure monitored by ambulatory blood pressure measurement in elderly hypertensive patients.

This study was designed to characterize the nocturnal fall of blood pressure (NFBP) of elderly hypertensive patients (EH), with or without cerebrovascular disease or diabetes mellitus, as measured by automated blood pressure (BP) monitoring. Systolic and diastolic BP and heart rate was measured every 15 minutes in 133 hospitalized patients with nearly similar schedules and diets. The patients were divided into five groups: I, normotensive elderly patients over age 65: II, EH without cardiovascular diseases, controlled without medication: III, EH with cerebral infarction, chronic stage: IV, EH with noninsulin-dependent diabetes mellitus: and V, hypertensives under age 65, without cardiovascular diseases. A significant NFBP was observed in the patients of groups I and V, a significant but smaller NFBP in the hypertensives of groups II and IV, and no NFBP in the patients of group III. Administration of the antihypertensive drugs, enalapril and nifedipine, tended to augment the NFBP. These preliminary observations showed that NFBP did occur in elderly hypertensives but the fall was smaller than that observed in younger hypertensives or elderly normotensives. Although the ambulatory BP measurements were useful in the overall clinical evaluation of elderly patients, NFBP in elderly patients was affected by hypertensive drugs and therefore NFBP should be interpreted with caution.

Aged↗
PubMed1992

[Long-term nasogastric feeding and complications of acute gastric ulcer in two elderly patients].

Some elderly patients with chronic illness such as stroke, or Parkinsonism cannot take food orally because of dysphagia. In such cases, tube feeding can be used as a supplement to oral intake when malnutrition is present. This route allows for easier nursing care and decreases the frequency of aspiration pneumonia. Complications of tube feeding include nutrient deficiency states, pulmonary aspiration, gastrointestinal and metabolic disorders. We report two cases with complications of acute gastric ulcer which was thought to be induced with long-term tube feeding. Case 1 was a 61-year-old male patient with Parkinson's disease for ten years. L-DOPA had been administered with good control of his condition. However, his ability to swallow has deteriorated gradually. As he often suffered from aspiration pneumonia, nasogastric tube feeding was performed. After three years of tube feeding, he suddenly vomited much bloody material. He died from massive bleeding with acute gastric dilatation. Autopsy showed giant acute gastric ulcer covered with coagulated blood. UL3, 50 mm in maximum diameter, was observed in the middle portion of the greater curvature, where the top of tube probably came in contact with the gastric wall. Case 2 was an 83-year-old female patient with stroke and chronic heart failure. She had been hospitalized for about one year because of the intermittent deterioration of her cardiac condition. Furthermore, her inability to swallow increased during her hospitalization. She also suffered from aspiration pneumonia. Nasogastric tube feeding was performed to prevent aspiration pneumonia and malnutrition. She died of acute heart failure after twelve months. Autopsy revealed heart dilatation, old myocardial infarction and stroke. In addition, two acute gastric ulcers (UL3.10 and 30 mm in diameter) were recognized; one was in the upper portion of the greater curvature, the other in the lower portion of the greater curvature. The location of these gastric ulcers was unusual. Moreover, they coincided with location of top of the nasogastric tube. From these two cases, we conclude that in long-term tube feeding the tip of the tube often comes in contact with the gastric wall, and gastric ulcer could be produced by repeated mechanical stimulus of the wall. Reports of acute gastric ulcer induced by tube feeding have not been published previously. Therefore, we should pay much attention to this complication in the care of the elderly people with long-term tube feeding.

Acute Disease↗
PubMed1992

Cardiac tamponade in chronic myelomonocytic leukemia: a case report.

Serous effusion is a rare complication of chronic myelomonocytic leukemia. We present a patient with chronic myelomonocytic leukemia who developed a massive pericardial effusion with cardiac tamponade as early manifestations. Numerous clumps of monocytes were observed in the effusion. The patient obtained rapid relief following the intravenous administration of etoposide (100 mg daily for 5 days). Few reports have documented details of such a case.

Cardiac Tamponade↗
PubMed1992

[CD7 (+) stem cell leukemia presenting different phenotypes in lymph node and bone marrow].

A 27-year-old male with systemic lymphadenopathy was diagnosed as lymphoblastic-type lymphoma by inguinal lymph node biopsy in September, 1990. Bone marrow at the initial diagnosis contained 55.4% lymphoblasts with a phenotype of peroxidase (-), CD7 (+), CD4 (-), CD8 (-). Lymphadenopathy and lymphoblasts in bone marrow disappeared after MACOP-B therapy. In December, 1990, however, the patient again noticed swelling of cervical lymph nodes. At this time, the bone marrow contained 36.4% myeloblasts with a peroxidase (+), CD7 (+), CD13 (+), CD33 (+) phenotype. Cytogenetic and genetic study revealed that the lymphoblasts at the initial diagnosis and the myeloblasts at relapse shared an common abnormal karyotype, 11p-, and the same rearranged band of T-cell receptor delta, gamma, beta genes, suggesting that these two blasts originated from the same clone. The blasts obtained from the cervical lymph node at relapse were still negative for peroxidase, in contrast to the blasts from bone marrow. These findings suggest that this leukemia originated from a stem cell and differentiated along multilineage pathways.

Adult↗
PubMed1992

[Two cases of acute promyelocytic leukemia in pregnancy and the effect of anthracyclines on fetal development].

Two patients with acute promyelocytic leukemia (APL) in 2nd and 3rd trimester of pregnancy are reported on. Case 1: 38-year-old female consulted our hospital because of bleeding tendency and pancytopenia in April, 1988. She was diagnosed as having APL with disseminated intravascular coagulopathy (DIC) and was found to be in the 14th week of gestation. Combined chemotherapy (BHAC-DMP) including the total dose (440 mg) of daunorubicin (DNR) resulted in intrauterine fetal death at 19 weeks of gestation. The fetus was severely anemic and the bone marrow was hypoplastic. Case 2: A 27-year-old female was diagnosed as having APL with DIC at 29 weeks of gestation. BHAC-DMP including 440 mg DNR achieved complete remission. At 35 weeks of gestation, she delivered a normal infant by Caesarean section. The child had normal hematological findings and showed normal growth. Both cases developed APL accompanied by DIC during pregnancy and were treated with a similar regimen including high dose of anthracyclines. Case 2 treated in the late period of gestation delivered a normal infant, while fetal death resulted in case 1, treated in the early period of gestation. We reviewed the literature regarding chemotherapy using anthracyclines during pregnancy.

Adult↗
PubMed1992

[Activation of protooncogenes by point mutations in hematological malignancies].

The activation of protooncogenes (ras, fms and myc genes) by point mutations in hematological malignancies are described in this review. Ras mutations are found in a variety of human malignancies at codon 12, 13, and 61. Generally, N-ras mutations are frequent in hematological malignancies. Fms mutation at codon 301 and 969, which are seen in 10 to 20% cases of AML and MDS, increase tyrosine kinase activity of the fms products. Ras and fms mutations are postulated to influence leukemogenesis at rather early stages. Burkitt lymphomas are characterized by specific chromosomal translocations between c-myc gene and one of the immunoglobulin genes. Furthermore, mutations in the 3' border of the exon 1 of c-myc are frequent, and may play an additional role in pathogenesis of Burkitt lymphoma.

Animals↗
PubMed1992

[Comparative study of postoperative complications in primary and secondary implantation of posterior chamber intraocular lens in cataract surgery for diabetic patients].

Postoperative complications of diabetic cataract cases with active stage diabetic retinopathy, which underwent simultaneous extracapsular lens extraction (ECCE) and posterior chamber intraocular lens (PC-IOL) implantation in 84 eyes, ECCE only in 38 eyes and secondary implantation of PC-IOL after ECCE in 23 eyes, were studied. In the eyes of the primary PC-IOL implantation group, fibrous response in 35 eyes (42%), posterior iris synechia in 10 eyes (12%), progression of diabetic retinopathy in 13 eyes (16%), after cataract in 11 eyes (13%), pupil capture in 4 eyes (5%) and decentration of lens optics in 3 eyes (4%) were appeared, while in the ECCE only group, fibrous response in 11 eyes (29%), posterior iris synechia in 4 eyes (11%), after cataract in 11 eyes (29%), progression of diabetic retinopathy in 6 eyes (16%) were observed. On the other hand, in the secondary PC-IOL implantation group, only fibrous response was appeared in 1 eye (4%), Although PC-IOL implantation has been so far considered contraindication in cases with cataract combined with active stage retinopathy, the present studies strongly suggest that secondary PC-IOL implantation would be good indication in these cases whose blood sugar was properly controlled and the retinopathy was burned out by panretinal photocoagulation soon after ECCE.

Aged↗
PubMed1991

Effect of ketone body (D-3-hydroxybutyrate) on neural activity and energy metabolism in hippocampal slices of the adult guinea pig.

The role of ketone body on neural activity and energy metabolism in the brain was investigated. Guinea pig hippocampal slices were prepared, and postsynaptic field potentials (PSPs) were recorded in the granular cell layer of the dentate gyrus. ATP and phosphocreatine (CrP) in the tissue slice were measured after 60 and 120 min incubation in standard medium (1) with 10 mM glucose, (2) with 10 mM glucose plus 20 mM D,L-3-hydroxybutyrate (3-OHBA), (3) without glucose, (4) with 20 mM 3-OHBA instead of 10 mM glucose. In (3), both ATP and CrP in the slice decreased to 40-45% of the original level after 120 min. On the other hand, the ATP level was well maintained even 120 min after incubation in (1), (2) and (4), whereas the CrP level decreased to 62% in (4). Further, slices were incubated in (3) and (4) for 30, 60, and 120 min, and the presence of PSP was tested. In (3), the number of slices from which PSPs could be recorded decreased, and after 120 min PSPs were hardly observed. In (4), that number decreased gradually, and only 45% of the slices showed PSPs after 120 min. These results indicate that 3-OHBA can be a substrate to produce high-energy phosphate but cannot maintain the neural activity as glucose does.

3-Hydroxybutyric Acid↗
PubMed1991

Experimental bacterial prostatitis in rats.

Experimental acute bacterial prostatitis in rats was induced by four different routes of bacterial inoculation. The most simple and reproducible method of producing bacterial prostatitis was to instil the bacterial suspension into the prostatic urethra after the administration of an appropriate antibiotic to prevent associated pyelonephritis.

Amikacin↗