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Biomedical subjects

H Kaneda

Publications and source records attributed to H Kaneda.

At least 55 records · Page 3Linked to original sources
PubMed1995

Effects of antidepressants on thyroid stimulating hormone release in rats under ether stress.

We found inhibitory effects of antidepressants (clomipramine, maprotyline, mianserin and zimelidine) and 5-hydroxytryptophan (5-HTP) on thyroid stimulating hormone (TSH) release induced by ether stress in freely moving rats. We confirmed that ether stress suppressed the plasma TSH levels after 30 min. We then injected intravenously 250 ng thyrotropin releasing hormone (TRH), 0.1 mg/kg clomipramine, 2.5 mg/kg maprotyline, 2.5 mg/kg mianserin, 0.5 mg/kg zimelidine and 25 mg/kg 5-HTP simultaneously. These materials blocked the influences on plasma TSH levels by the ether stress. Serotonergic antidepressants (clomipramine, zimelidine) and 5-HTP (precursor of serotonin) had a higher potency against the ether stress. These results suggest that antagonizing effects against the ether stress may involve the serotonergic system in the pituitary gland.

5-Hydroxytryptophan↗
PubMed1995

[Long-term hemodialysis treatment using femoral vein puncture method (FV-method) as blood access in 12 patients].

It is well known that blood access is essential for long-term hemodialysis treatment. Arteriovenouos fistula (AVF) is the most widely used method. However, this method of access frequently fails (access failure) as a result of stenosis. We attempt simple femoral vein puncture (FV-method) instead of AVF in such patients and have experienced 12 patients who were undergoing hemodialysis treatment using the FV-method, three times a week for more than one year. We devised special needles (18- and 19-gauge) for the FV-method. Generally, we use a 19-gauge needle with 4 side holes. We discuss here the results of 12 patients consisting of 4 males and 8 females with a mean age of 57.9 years, a mean duration of dialysis of 10.0 years, and a mean duration of FV-method of 3.5 years. Their underlying diseases were chronic glomerulonephritis (9 patients), diabetic nephropathy (2 patients) and nephrosclerosis (1 patient). Before the use of the FV-method, AVFs were attempted a man of 3.8 times and an artificial graft, 4 times in 3 patients. Ten patients were outpatients and 2 were inpatients. As for the indications of the FV-method, 11 patients had access failure and another had suffered from heart failure resulting from an over flow of blood through AVF. KT/V, PCR and TACBUN were measured monthly and were within the normal range in almost all of the patients. Concerning complications of the FV-method, hematoma formation after detachment of the needle at the end of dialysis and pain at needle puncture were sometimes noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Alteration in regional brain neuropeptides following intracerebroventricular infusion of excitotoxins in rats.

We determined regional brain concentrations of somatostatin (SS), neuropeptide Y (NPY) and arginine-vasopressin (AVP) in 3- and 13-month-old rats. We also examined the effects of the excitotoxins, ibotenic acid (IA), kainic acid (KA), and quinolinic acid (QA) on regional levels of brain neuropeptides in rats. Excitotoxins were infused continuously into the lateral ventricle for 14 days using an osmotic minipump. Our results indicate that; (1) NPY in the brain is especially vulnerable to aging, compared to AVP. (2) IA induces a decrease in brain regional concentrations of neuropeptides and the effects are different from those of other excitotoxins, for example, KA and QA. (3) These effects of IA on neuropeptides may be dependent on the age of the animals when exposed and on the dose of IA.

Age Factors↗
PubMed1994

Nuclear but not mitochondrial genome involvement in human age-related mitochondrial dysfunction. Functional integrity of mitochondrial DNA from aged subjects.

The role of mtDNA and nuclear genome in human aging was examined by their intercellular transfer using skin fibroblasts and mtDNA-less HeLa cells (rho o-HeLa cells). We found in vivo age-related reductions in the activity of cytochrome c oxidase in human skin fibroblasts obtained from 16 donors of various ages (0-97 years). The abnormality in mitochondria of the aged donors was not attributable to either decrease in the copy number of mtDNA molecules or increase in the copy number of deletion mutant mtDNA molecules, but to significant decrease in overall polypeptide synthesis in the mitochondria. However, intercellular mtDNA transfer experiments showed that fibroblast mtDNA from elderly donors is functionally intact. By contrast, intercellular transfer of HeLa nuclei to fibroblasts from aged donors restored cytochrome c oxidase activity, suggesting that the age-related phenotype was nuclear recessive. However, during subsequent cultivation of these hybrids, the activity gradually reduced again, associated with gradual chromosome loss. These observations support the idea that accumulation of nuclear recessive somatic mutations, but not mtDNA mutations, is responsible for the in vivo age-related mitochondrial dysfunction observed in human skin fibroblasts.

Aged↗
PubMed1994

Cerebrospinal fluid (CSF) neuropeptide Y- and somatostatin-like immunoreactivities in man.

We have measured cerebrospinal fluid (CSF) neuropeptide Y-like immunoreactivity (NPY-LI) and somatostatin-like immunoreactivity (SLI) in control subjects and in patients with various neurologic disorders. We observed a significant reduction in CSF SLI in control subjects over 60 years of age, compared with the younger controls. CSF SLI was significantly decreased in multiple sclerosis (MS), or Guillain-Barre syndrome, compared with that of age-matched control subjects. A reduced concentration of NPY-LI was found in CSF of patients with MS. We have also examined the molecular heterogeneity of peptide-LI in CSF. Gel chromatography, not high performance liquid chromatography (HPLC), suggested two NPY immunoreactive materials in CSF. Gel chromatography and HPLC revealed three SLI components in CSF: somatostatin 14, somatostatin 28 and a higher molecular weight precursor. Our results suggest that 1) there may be more than one form of NPY in human CSF, and 2) somatostatin neurons might be more susceptible to alteration than NPY neurons in various pathological conditions and aging.

Adult↗
PubMed1993

[A long-term hemodialysis patient complicated with systemic calciphylaxis].

A 46-year-old male patient underwent long-term hemodialysis treatment had suffered from calciphylaxis (defined by Selye), such symptoms as advanced systemic vascular calcification, rapid progression of gangrene on both fingers and toes, disturbance of consciousness, and sclerosis and obstruction of the superficial vein after venipuncture during 11.5 years of dialysis. Furthermore, he had a long history (30 years) of heavy smoking. He died as a result of sepsis due to pneumonia after 12.5 years of dialysis. He had received dialysis treatment using a small amount of dialysate (50 liters on a recirculating system) for 8.5 years and had been dialysed 2 and 2 or 3 times a week for 10 years. As a result of this insufficient dialysis treatment, his characteristic laboratory data showed hypocalcemia, hyperphosphatemia, elevated calcium-phosphorus product, advanced metabolic acidosis, hyperalkaliphosphatemia and elevated serum parathyroid hormone. Autopsy revealed the following: 1) enlargement parathyroid gland enlarged in two (4.0 g and 2.0 g, respectively) showing adenomatous hyperplasia presenting cord-like arrangement of chief cells and water-clear cells, 2) systemic medial calcification in radial, ulnar, renal, mesenteric and brain arteries, and 3) Berline-blue positive iron deposit in calcified arteries in mesenteric and parathyroid tissue. From these results, we concluded that factors (challengers) related to the appearance of calciphylaxis might be as follows: 1) advanced secondary hyperparathyroidism, 2) long-term uremic state, 3) administration of VD2 and VD3, 4) iron salt injection, and 5) a long history of heavy smoking. We speculated that these challengers might act synergistically to cause calciphylaxis.

Calciphylaxis↗
PubMed1992

Action of ebselen as an antioxidant against lipid peroxidation.

The action of ebselen (2-phenyl-1,2-benzoisoselenazol-3(2H)-one) as an antioxidant was studied under various conditions to clarify how it prevents oxidative damage. It did not react with diphenylpicrylhydrazyl nor did it suppress the oxidation of methyl linoleate in acetonitrile solution or in aqueous dispersions induced by free radical initiator, suggesting that ebselen does not act as a potent radical scavenging antioxidant. On the other hand, it suppressed the oxidation of methyl linoleate emulsions in aqueous dispersions induced by iron. It also suppressed the spontaneous oxidation of rat brain and liver homogenates, but it did not suppress the oxidation of these homogenates induced by a free radical initiator. It was also found that ebselen reduced the fatty acid hydroperoxides to their corresponding alcohols and this reaction was enhanced by the presence of glutathione. These results suggest that ebselen acts as an antioxidant by reducing hydroperoxides, but that it does not act as a radical-scavenging antioxidant.

Animals↗
PubMed1992

Co-administration of progabide inhibits haloperidol-induced oral dyskinesias in rats.

Vacuous chewing movements in rats may be an animal analogue of the human motor disorder, tardive dyskinesia. The movements are phenomenologically and pharmacologically similar to tardive dyskinesia. The pathophysiology of these involuntary oral movements, and perhaps of tardive dyskinesia, are likely to include both dopamine receptor changes, and alterations in GABA (gamma-aminobutyric acid) system function. In an attempt to test the involvement of GABA system dysfunction in these movements, we treated rats chronically with water alone, haloperidol alone, the GABA agonist progabide alone, and haloperidol plus progabide. Sprague-Dawley rats received haloperidol (1.5 mg/kg per day) in their drinking water and progabide (100 mg/kg per day) in their food for 12 months. After 12 months of treatment, haloperidol had induced vacuous chewing movements when administered alone, but the prevalence of the movements was decreased by 40% with the coadministration of progabide. Moreover, the haloperidol-progabide-treated animals did not merely demonstrate movement suppression but actual inhibition of movement onset, as determined by an additional progabide-withdrawal experiment. These data would suggest that progabide and perhaps other GABAmimetic compounds can prevent the development of tardive dyskinesia in man.

Administration, Oral↗
PubMed1992

Repeated administration of antidepressant drugs reduces regional somatostatin concentrations in rat brain.

A possible role for somatostatin in affective disorders is suggested by its low concentration in cerebrospinal fluid of patients with depression. Therefore, we studied the regional effects of antidepressant drugs and antimanic agents on somatostatin concentrations in rat brain. Repeated, but not acute, administration of clomipramine, a specific serotonin uptake inhibitor, caused a highly significant, widespread reduction in somatostatin levels. Somatostatin content was similarly reduced in the hypothalamus, and midbrain and thalamus following repeated administration of zimelidine, another specific serotonin uptake inhibitor. Repeated administration of either imipramine, maprotiline, mianserin, carbamazepine or zotepine were without effect on somatostatin levels. These results suggest that somatostatin in the brain might be involved in therapeutic effects of some of antidepressant drugs.

Animals↗
PubMed1991

The effect of intracerebroventricular administration of somatostatin on prolactin and TSH release in rats.

We investigated the effect of intracerebroventricular (icv) administration of somatostatin (SRIF) on prolactin (PRL) and thyroid-stimulating hormone (TSH) release in freely moving rats chronically cannulated with an atrial catheter. The plasma PRL levels were significantly elevated following the icv administration of 0.5 microgram SRIF. No further increase in PRL following the icv administration of SRIF were found in the rats in the course of repeated intravenous of injection of 5.0 mg/kg sulpiride, a specific D2 receptor antagonist. On the other hand, the injection of 5.0 micrograms SRIF resulted in no significant change in the plasma TSH levels. These results suggest that the effect of SRIF on PRL release was exerted through brain D2 receptors.

Animals↗
PubMed1990

Neuroleptic-induced vacuous chewing movements as an animal model of tardive dyskinesia: a study in three rat strains.

Vacuous chewing movements (VCMs) in three different rat strains developed at considerably different rates after 19 weeks of continual haloperidol treatment at an average daily dose of 1.5 mg/kg. Sprague Dawley (SD) rats displayed relatively high rates of VCMs with low variability, compared to Wistar (W) and Long Evan (LE) rats. Atropine decreased but did not abolish VCMs in two of the three strains (LE greater than SD). After haloperidol withdrawal, VCMs remitted gradually in all strains, but least rapidly in the SD rats. In a separate group of SD rats. VCMs were rated weekly from the start of haloperidol treatment and showed considerable interindividual variability. Even after 24 weeks of continuous haloperidol, 12 out of 32 treated rats showed no VCMs at all, while 13 out of 32 had intense movements, analogous to the clinical situation in which only some patients treated with neuroleptics develop tardive dyskinesia. These results indicate that there are individual and strain differences in the development of VCMs, and suggest that there may also be genetically determined differences in the development of tardive dyskinesia.

Animals↗
PubMed1988

Early diagnosis of hepatocellular carcinoma with lectin electrophoresis of serum alpha-fetoprotein.

A sensitive procedure involving lectin affinity electrophoresis of alpha-fetoprotein (AFP) was established. AFPs electrophoresed on lectin-containing gels were blotted on nitrocellulose membrane which was precoated with the specific antibody to AFP and stained with peroxidase-labeled anti-AFP antibody. This method could detect as little as 4 micrograms/l of purified AFP dissolved in buffer, or 50 micrograms/l in serum specimens. A number of patients with liver disease have been followed for long periods in Nihon University Hospital, Tokyo. Serum specimens were collected serially and stored frozen. We have reinvestigated retrospectively 6 series of serum specimens by the lectin-immunoblotting technique and found 3 cases that revealed a hepatocellular carcinoma-specific AFP variant at a very early stage, in advance of any other evidence of hepatocellular carcinoma by clinical examination.

Carcinoma, Hepatocellular↗