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Biomedical subjects

T Ichikawa

Publications and source records attributed to T Ichikawa.

At least 541 records · Page 30Linked to original sources
PubMed1986

Immunohistochemical localization of urotensins I and II in the caudal neurosecretory neurons of the carp Cyprinus carpio and the sharks Heterodontus japonicus and Cephaloscyllium umbratile.

Using antisera to urotensins I and II (UI and UII), in the carp, Cyprinus carpio, three types of caudal neurosecretory neurons were identified: those with both UI- and UII-immunoreactivities, those with only UI-immunoreactivity and those with only UII-immunoreactivity. The last type of neurons exceeded the other types in number, while neurons immunoreactive with both UI and UII antisera were relatively few. The axons of neurons of these three types terminated around the capillaries in the urophysis. In the cat shark, Heterodontus japonicus and the swell shark, Cephaloscyllium umbratile, two types of neurons were identified: those with both UI- and UII-immunoreactivities and those with only UII-immunoreactivity. Neurons of the former type were greater in number than the latter. The axons of neurons of both types terminated in the neurohemal areas.

Animals↗
PubMed1986

Stimulation of chenodeoxycholic acid excretion in hypercholesterolemic mice by dietary taurine.

The effects of dietary taurine on fecal steroid excretion and bile acid pool size were investigated in Jcl: ICR strain mice. The mice were fed on semi-purified diets for five weeks: a cholesterol-free diet (Standard), a lithogenic diet containing 0.5% cholesterol and 0.25% sodium cholate (C-CA) and a lithogenic diet supplemented with 5% taurine (C-CA + 5% taurine). The changes in fecal steroid excretion were studied as a function of time and the bile acid pool size was estimated. Dietary taurine affected fecal bile acid excretion both quantitatively and qualitatively. No change in bile acid pool size was observed. The fecal excretion of bile acids increased in taurine-supplemented mice. The increase in the fecal neutral steroid excretion was less than that in C-CA fed mice. The proportion of chenodeoxycholic acid (CDCA) and the related bile acids to total bile acids increased both in the fecal bile acids and in the bile acid pool. Therefore, the protective effect of dietary taurine against cholesterol gallstone formation may be related to the stimulation of bile acid synthesis, especially of CDCA and related compounds.

Administration, Oral↗
PubMed1986

Cloning and sequence analysis of cDNAs encoding precursors of urotensin II-alpha and -gamma.

The primary structures of the precursors of urotensin II (UII)-alpha and -gamma, neuropeptide hormones of the caudal neurosecretory system of the carp, Cyprinus carpio, have been determined by analyzing the nucleotide sequences of cloned DNAs complementary to the mRNAs encoding them. A cDNA library, constructed with poly(A)+RNA in the preterminal spinal cord, was screened using 32P-labeled synthetic oligonucleotides representing all possible cDNA sequences corresponding to the pentapeptide common to all forms of carp UII (UII-alpha, -beta, and -gamma). Twenty out of 39 positive clones were analyzed with the restriction endonucleases, HindIII and PvuII, and classified into 4 groups. Nucleotide sequence analysis of 4 clones representing each group revealed that 2 clones encode the precursor of UII-alpha and the other 2 that of UII-gamma. Both precursors consist of 125 amino acid residues, and UII-alpha and -gamma exist at the carboxyl-termini preceded by Arg-Lys-Arg. The homology in both nucleotide and amino acid sequences between the precursors of UII-alpha and -gamma is more than 90%, suggesting that the genes were generated from a common ancestral gene by duplication. There is no sequence homology between the precursors of UII and urotensin I, another peptide hormone of the caudal neurosecretory system, nor between the precursors of UII and somatostatin-14. RNA transfer blot analysis indicated that mRNAs encoding the precursors of UII-alpha and -gamma are present in the spinal cord but not in the brain, intestine, liver, or kidney of the carp.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

[Study on the use of cefotiam in neonates].

Pharmacokinetic and clinical studies were carried out regarding the use of cefotiam (CTM) in the treatment of infections in newborn infants. Absorption and excretion: CTM was administered by bolus intravenous injection at a dose of 20 mg/kg to 9 newborns ranging in age from 1 to 28 days (gestational age, 34-40 weeks; birth weight, 2,000-3,380 g) and 6 infants aged 30 to 87 days (gestational age, 33 approximately 40 weeks; birth weight, 2,100-3,600 g) and its serum concentration and urinary excretion were determined. In the newborns, mean serum concentrations were 43.3 micrograms/ml at 1/4 hour, 36.7 microgram/ml at 1/2 hour, 27.8 micrograms/ml at 1 hour, 17.7 micrograms/ml at 2 hours, 8.8 micrograms/ml at 4 hours and 4.8 micrograms/ml at 6 hours, and in the infants, they were 44.5 micrograms/ml, 31.2 micrograms/ml, 19.1 micrograms/ml, 7.6 micrograms/ml, 2.2 micrograms/ml and 0.7 micrograms/ml at the above sampling times, respectively. Mean half-lives were 1.92 hours for the newborns and 0.96 hour for the infants, and mean urinary recoveries within 6 hours were 41.2% and 50.1% for the newborns and the infants, respectively. Taking individual differences into account, serum peak levels (at 1/4 hour) in newborns were very similar to each other irrespective of age (days after birth), and did not appear to be greatly different from those in infants. Half-lives, however, became shorter with aging, and the half-life of the serum CTM level in infants of about 1 month old should be close to those in young children or school-age children. From these observations, it is suggested to establish a standard regimen in which CTM is administered at a dose of 20 mg/kg once or twice a day to newborns within 3 days after birth, twice or 3 times a day to those aged 4 to 7 days, and 3 or 4 times a day to those aged 8 days or older. Clinical study: The CTM was administered to 11 patients with acute pneumonia, 2 patients each with suspected septicemia and with bullous impetigo, 1 patient with purulent lymphadenitis, 3 patients with idiopathic respiratory distress syndrome and 1 patient with pneumothorax, and its clinical effect was investigated. Excellent responses were observed in 12 of the 15 evaluated cases,good responses in 2, and a poor response in 1, thus an overall clinical effectiveness was 93.3%.(ABSTRACT TRUNCATED AT 400 WORDS)

Absorption↗
PubMed1986

[Right ventricular ischemia evaluated by radionuclide ventriculography].

The clinical usefulness of radionuclide ventriculography (RNV) was evaluated in patients with right ventricular ischemia. The subjects consisted of 25 patients with acute inferior myocardial infarction, 19 patients with old myocardial infarction and six patients with angina pectoris who had severe stenosis of the right coronary artery. In patients with acute inferior myocardial infarction, follow-up radionuclide studies were performed during the recovery periods on the first, 7th-14th, and 30th hospital day. Fifteen of the 25 patients initially had decreased right ventricular ejection fractions (evidence of right ventricular infarction). The mean value was 28 +/- 8% on the initial day, but 7-14 days and 30 days after the acute attack, it improved markedly to 36 +/- 9% and 39 +/- 9%, respectively. Regional wall motion abnormality resolved in 10 of the 15 patients on the 30th hospital day. In 25 patients with old myocardial infarction or with angina pectoris, RNV was performed at rest and during supine exercise to determine the influence or right coronary artery disease. Right ventricular ejection fraction was changed by exercise from 42 +/- 7% to 44 +/- 10% in patients with proximal artery lesions, and from 45 +/- 7% to 50 +/- 10% in patients with distal artery lesions. Right ventricular ejection fraction increased in patients with isolated right coronary artery disease (rest: 44 +/- 8%, exercise: 49 +/- 9%), decreased in patients with combined left anterior descending artery disease (rest: 40 +/- 6%, exercise: 38 +/- 11%) and increased in patients with combined circumflex artery disease (rest: 43 +/- 5%, exercise: 47 +/- 6%). We concluded that right ventricular infarction is a frequent complication in patients with inferior myocardial infarction. However, right ventricular ejection fraction and right ventricular regional wall motion abnormality improve dramatically within one month. Stress-induced ischemia would be rare in patients with isolated right coronary artery disease. The above findings support the notion that the right ventricular myocardium has peculiar coronary perfusions.

Angina Pectoris↗
PubMed1986

[Clinicopathologic study of intramammary cancer residuals after outpatient excisional biopsy of breast cancer].

Seventy-four breast cancer patients, who had undergone outpatient excisional biopsy followed by radical mastectomy, were divided into three groups according to the types of intramammary cancer residuals: no cancer residuals--45 patients, noninvasive cancer residuals--15, and invasive cancer residuals--14. The invasive cancer residual group included nine patients with axillary metastasis and showed a significantly higher rate of five-year recurrence (8/14) than the other two groups. In some of the patients with invasive cancer residuals, the lesions were more advanced and aggressive by nature. Histopathologically, invasive cancer residuals closely correlated to the nondesmoplastic infiltrating tumor border, and noninvasive cancer residuals to intraductal cancerous spread. Most intramammary cancer residuals were found close to the wounds made by biopsy.

Ambulatory Surgical Procedures↗
PubMed1986

Severe visual disturbance after exposure of the optic canal during intranasal ethmosphenoidectomy.

The cause of disturbed visual acuity associated with intranasal ethmosphenoidectomy is, on the one hand, a direct injury to the optic nerve. In this case, the disturbance in visual acuity develops immediately after the operation, and severe visual complications with a poor prognosis are found. On the other hand, in the two cases presented in this paper, the disturbed visual acuity develops postoperatively. In this case, it is necessary to take various possibilities into consideration, such as indirect effects of intraorbital bleeding, and damage to the lamina papyracea due to indirect and direct injury. Moreover, effects on the peri-optic nerve area and small blood vessels within the osseous optic canal should be considered. After thorough consideration and observation of the response to conservative therapy, such complications should be treated by investigating whether or not decompression of the optic nerve is effective.

Adult↗
PubMed1986

Organization of choline acetyltransferase-containing structures in the forebrain of the rat.

The cholinergic structures in the forebrain of the rat were studied immunohistochemically with a monoclonal antibody to choline acetyltransferase (ChAT) which has proven to be particularly suited to reveal the trajectory of ChAT-positive fibers and their terminations. The habenulo-interpeduncular tract contained the most distinctly ChAT-positive fibers. Here, ChAT-positivity was demonstrated in the perikarya, fibers and terminal field. From the basal forebrain, ChAT-positive fiber bundles could be followed rostrally to the olfactory bulb, dorsomedially to the neocortex and hippocampus, and dorsocaudally to the hippocampus. Terminations of ChAT-positive fibers in these regions were either boutons terminaux (in the interpeduncular nucleus), finely granular (in the hippocampus) or a network of varicose fibers (in the olfactory bulb and neocortex). Cholinergic terminal fields were also demonstrated in the following regions: the nucleus of the lateral olfactory tract, the olfactory tubercle, the pyriform cortex, the lateral nucleus and part of the basal nucleus of the amygdala, the caudate-putamen, the nucleus accumbens, some thalamic nuclei, and the suprachiasmatic nucleus of the hypothalamus. In most of these regions, ChAT-positivity appeared as either fine granules or a meshwork of varicose fibers.

Amygdala↗
PubMed1985

Immunochemical study on the mannans of Candida albicans NIH A-207, NIH B-792, and J-1012 strains prepared by fractional precipitation with cetyltrimethylammonium bromide.

The mannans of Candida albicans NIH A-207 (A strain, serotype A), C. albicans NIH B-792 (B strain, serotype B), and C. albicans J-1012 (J strain, serotype C) prepared by fractional precipitation with cetyltrimethylammonium bromide (Cetavlon) were investigated for their immunochemical properties. Upon treatment with 10 mM HCl at 100 degrees C for 60 min, the mannans of A and B strains each released a mixture of manno-oligosaccharides ranging from hexaose to mannose together with (for each one) an acid-modified mannan, while J-strain mannan released lower oligosaccharides, tetraose to mannose. The acid-modified mannan of B strain did not show antibody-precipitating activity against homologous antiserum, whereas acid-modified A- and J-strain mannans retained most of this activity. The acid-released oligosaccharides were assumed to consist of beta-1,2-linked D-mannopyranosyl residues from the results of specific rotation and proton magnetic resonance studies.

Antigens, Fungal↗
PubMed1985

[Extraordinary variant of the alpha rhythm].

The authors describe a variant of alpha rhythm, which is remarkable because of its great amplitude (200-300 microV). It is observed quite exceptionally in children and adolescents with a severe encephalopathy of either ante- or perinatal etiology. They suggest that the surplus amplitude of this alpha rhythm could depend upon a deafferentation of the occipital cortex in patients with severe amblyopia.

Agenesis of Corpus Callosum↗