Biomedical subjects

Y Kojima

Publications and source records attributed to Y Kojima.

At least 235 records · Page 13Linked to original sources

PubMed1995

Macroscopic observations of mammary glands and teats of Japanese serows, Capricornis crispus, with special reference to past gestation.

Mammary glands and teats were examined to estimate the reproductive history of Japanese serows. The presence of milk was an indicator of reproduction in the previous year. The thickness of the mammary glands is indicative of their function. The females whose mammary glands are more than 10 mm thick may be regarded as having delivered half a year before. The distance between teats is not always indicative of the function of the mammary glands. Animals with teats 10 mm or less in length and those with teats longer than 10 mm may be judged to be nulliparous and multiparous, respectively.

Aging↗

PubMed1995

Dopamine responsiveness of human prolactinoma cells as determined by the reverse hemolytic plaque assay.

The responsiveness in vivo to dopamine of prolactin (PRL) secretion in patients with prolactinoma was compared with that in vitro of single cells obtained from the same prolactinomas by surgical operations. Six patients with prolactinoma showing various degrees of hyperprolactinemia were challenged by bromocriptine suppression test (2.5 mg, peroral) before operation. Bromocriptine administration caused a decrease in the serum PRL concentration ranging 24-95% and there was no correlation between the basal PRL level and bromocriptine-induced inhibition. Monodispersed pituitary cells obtained from the prolactinomas by operation were subjected to a reverse hemolytic plaque assay for PRL to determine PRL secretion at the single cell level under basal conditions as well as in response to dopamine. The percentage of plaque-forming cells under basal conditions ranged 15-55% among the prolactinomas. The percentage of plaque-forming cells and plaque area were decreased in a dose-dependent manner by 10(-7) - 10(-5) M dopamine for the pituitary cells obtained from some adenomas but not for those from other adenomas. When the inhibition rates in vitro due to 10(-5) M dopamine in these two parameters were compared with the inhibition rate in vivo in the serum PRL concentration due to bromocriptine, it was found that there was a significant correlation between them. These results show that the reverse hemolytic plaque assay can be used to determine in vitro responsiveness to dopamine of PRL secretion from single prolactinoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Mammosomatotroph adenoma cells secrete both growth hormone and prolactin.

Pituitary adenoma cells from a mammosomatotroph adenoma obtained from a 21-year-old female presenting with acromegaly and amenorrhea were investigated by sandwich cell immunoblot assay, immunohistochemistry, and electron microscopy. The new, simple technique of sandwich cell immunoblot assay could detect two hormones secreted in the same one cell, and found that 89% of mammosomatotrophs secreted both growth hormone (GH) and prolactin (PRL). Immunohistochemistry showed that the tumor cells were positive for both GH and PRL. Electron microscopy showed cells contained granules ranging in size form 150 to 500 nm. This is the first demonstration of both GH and PRL in the same mammosomatotroph cell. Sandwich cell immunoblot assay can measure the amount of secreted hormone, allowing a new approach to the investigation of mammosomatotroph adenomas.

Adenoma↗

PubMed1995

[Distribution and origin of corpola amylacea in the vestibulocochlear nerve].

The distribution of the corpora amylacea in the vestibulocochlear nerve is very limited. We studied the relation between the number of corpora amylacea in the cochlear nerve and the aging of cochlea and developed some hypotheses on the origin of corpora amylacea. This study involved 11 subjects, 14 samples. The results were as follows. There was no relationship between the number of corpora amylacea in the cochlear nerve and aging of the cochlea. Corpora amylacea probably have no relation to cochlear disorders. However, it was reported that corpora amylacea were produced more than 10 years after the organ's obstruction. There is a possibility that corpora amylacea increased 10 years after disorders developed in the cochlear nerve. There is a neurilemma-Schwann sheath junction (NSS junction) in the vestibulocochlear nerve. Corpora amylacea characteristically exist only in the central portion of the vestibulocochlear nerve on one side of the NSS junction. There are 3 possibilities regarding the origin of corpora amylacea which include consideration of the hypothesis that the NSS junction is the point where the vestibulocochlear nerve pierces the encephal dura mater. 1) Supposing that the origin of the corpora amylacea is the vestibulocochlear nerve itself, we would expect that the oligodendrocytes which are components of the vestibulocochlear nerve to be the origin of the corpora amylacea because they exist only in the central portion of the nerve, but not in peripheral portions of the nerve. 2) Supposing that the origin of the corpora amylacea is not the vestibulocochlear nerve itself, we would expect that the perineurium from the encephal dura mater to be the origin of corpora amylacea.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1995

Generation of novel rapamycin structures by microbial manipulations.

A new rapamycin producing culture was isolated and designated as Actinoplanes sp. N902-109. The addition of a cytochrome P-450 inhibitor and precursor feeding using this culture, and biotransformation approaches generated new rapamycin analogs with modifications at C-4, C-9, C-16, C-27, C-28 and/or C-39. The immunosuppressive activity of the resulting analogs was established in the mixed lymphocyte reaction assay.

Actinomycetales↗

PubMed1995

Sulphate reduction and methanogenesis in the ovine rumen and porcine caecum: a comparison of two microbial ecosystems.

A series of experiments was conducted to study the relationship between methanogenesis and sulphate reduction in ovine rumen and porcine caecum. Effect of 2-bromoethane sulphonate on hydrogen production by digesta suggested that the most important H2-disposal system in the rumen is methanogenesis and that methanogenesis is not predominant H2-disposal system in the porcine caecum. This inference was supported by the difference in predominant H2-utilizers in these two microbial ecosystems; Methanogenic bacteria (MB) were predominant in the rumen and sulphate reducing bacteria (SRB) were predominant in porcine caecum. Free sulphate levels in digesta appear to affect the relationship between MB and SRB. Sulphate levels in the rumen were likely to be insufficient for SRB to outcompete MB.

Animals↗

PubMed1995

[Fournier's gangrene in a patient with perirectal abscess: a case report].

A case of an 81-year-old man with Fournier's gangrene was reported. The patient visited our hospital complaining of scrotal swelling and redness. Perirectal abscess was found and ultrasound study revealed thickness of scrotal skin and normal testes. The patient was immediately treated with antibiotics, incision and debridement of the scrotal skin. The lesion healed 8 weeks later.

Abscess↗

PubMed1995

Acetylcholinesterase-positive afferent axons in mucosa of urinary bladder of adult cats: retrograde tracing and degeneration studies.

Acetylcholinesterase (AchE)-positive afferent axons in the mucosa of the cat urinary bladder were examined in the present experiments. Small-sized dorsal root ganglion cells containing AchE enzyme activity were labelled by injection of retrograde tracer (wheat germ agglutinin conjugated to enzymatically inactive horseradish peroxidase gold complex) into the bladder mucosa of adult cats. Results show that 48.9% (90/184) of the labelled ganglion cells possessed AchE enzyme activity. Following unilateral dorsal root ganglionectomy (L2-5, S1-3), a total of 6619 unmyelinated axon terminals were examined in the bladder mucosa, including 691 degenerating axon terminals. Percentages (8.;6-16.1%) of degenerating axon terminals in the ganglionectomized animals (1, 2, 3, 10 and 21 days post-operated) were significantly higher than those of controls (3.1%) and the 60-day post-operated animals (3.2%). Approximately one-half (47.9%) of the degenerating axon terminals observed in the 1-21 day post-operated animals were AchE-positive. Further examination also disclosed that the population of the intact (not affected by ganglionectomy) AchE-positive axon terminals at 60 days (59.3%) was significantly greater than that of controls (45.6%). The AchE-positive terminals containing few synaptic vesicles were significantly increased in number in the 60 day post-operated cats. In conclusion the present study demonstrates that one half of afferent axons in the mucosa were AchE-positive. The increase in AchE-positive afferent axon terminals containing few synaptic vesicles may be derived from contralateral dorsal root ganglia resulting from sprouting following dorsal root ganglionectomy.

Acetylcholinesterase↗

PubMed1995

[Pseudo-Bartter syndrome without hypopotassemia: a case with unilateral multicystic dysplastic kidney and congenital contralateral hyronephrosis].

A 2-month-old girl having a left multicystic dysplastic kidney with contralateral mild hydronephrosis is described. Furosemide was administered orally because of hyperpotassemia during the period between 1 month and 7 months of age. Peripheral plasma renin activity and plasma aldosterone activity increased at the age of 6 months, and ultimately reached the peak at 9 days after discontinuation of furosemide at the age of 7 months. Peripheral plasma renin activity and plasma aldosterone activity were normalized at the age of 11 months. Blood pressure during the whole period was normal. Contralateral hydronephrosis was improved gradually. The level of serum creatinine became normal at the age of 50 days. A case with a high level of plasma renin and aldosterone activity temporarily induced by furosemide was reported. Pathophysiology of pseudo-Bartter syndrome without hypopotassemia due to furosemide is discussed.

Aldosterone↗

PubMed1995

Relative zinc-binding capacity of metallothionein in hepatic cytosols of zinc-injected rats.

In order to determine the zinc-binding capacity of metallothionein in hepatic cytosols of zinc-injected rats, we examined the relationship between zinc contents in cytosols and metallothionein fraction in rat livers. Each rat was injected intraperitoneally once with 0.9% NaCl or zinc (10, 20, 40 or 60 mg zinc/kg b.w.) and was killed 14 h after injection. The distribution profiles of the hepatic cytosols of zinc-injected rats on a Sephadex G-75 column showed that the increased zinc was attributable to the metallothionein and high molecular weight proteins. Our results demonstrated that 63% of the increased zinc in hepatic cytosols of zinc-injected rats was bound to metallothionein and that 23% of the increased zinc was bound to high molecular weight proteins. These results suggest that the mechanisms of zinc accumulation in rat liver are different from those of cadmium accumulation.

Animals↗

PubMed1995

The motoneurons innervating the musculus levator palpebrae superiors in the monkey, cat and rabbit.

The motoneurons innervating the musculus levator palpebrae superioris (LPS) of the monkey, the cat and the rabbit were studied using horseradish peroxidase (HRP). Furthermore, LPS motoneurons of the cat and rabbit were studied by the double-labeling method using two fluorescent dyes as retrograde neuronal tracers. After injection of HRP into the right LPS of the monkey and the cat, HRP-labeled neurons were found only in the central caudal nucleus with contralateral preponderance. In contrast, after HRP injection into the right LPS of the rabbit, HRP-labeled neurons were found only in the contralateral oculomotor nucleus. In the double-labeling study, after injection of fast blue (FB) into the right LPS and diamidino yellow dihydrochloride (DY) into the left LPS of the cat and the rabbit, no double-labeled neurons were noted in the central caudal nucleus of the cat nor in the oculomotor nucleus of the rabbit, although double-labeled neurons were identified in the central caudal nucleus of the monkey in our previous study. Cross-innervation was confirmed in the mammals lower than the monkey.

Amidines↗

PubMed1995

Activated protein C resistance: molecular mechanisms.

Activated protein C (APC) resistance is usually associated with a single DNA mutation predicting replacement of Arg506 by Gln in factor V (FV). Studies using synthetic peptides suggest that FV residues 493-506 provide factor Xa (FXa) and protein S binding sites. Biochemical studies were performed to test the hypothesis that the Arg506Gln FV mutation causes APC resistance and to define the nature of the resistance of Gln506-FVa to APC. Purified Gln506-FV conveyed APC resistance to FV-deficient plasma in APTT and FXa-1-stage assays. Purified Gln506-FVa, generated either by thrombin or by FXa, was resistant to APC. Nonetheless, Gln506-FVa was not completely resistant to APC since it was inactivated by APC approximately 10-fold slower than normal Arg506-FVa, probably due to cleavage at Arg306. This reduced but significant susceptibility of Gln506-FVa to APC inactivation may help explain why APC resistance, especially for heterozygotes, is a relatively moderate risk factor for venous thrombosis. Cardiolipin promotes APC anticoagulant activity better than FXa coagulant activity, and antibodies from some antiphospholipid antibody syndrome patients downregulate APC activity. Thus, acquired APC resistance may contribute to pathogenesis of thrombosis in the antiphospholipid antibody syndrome.

Amino Acid Sequence↗

PubMed1995

[Double cancers of renal cell carcinoma and testicular seminoma: a case report].

A case of metachronous presentation of renal cell carcinoma and testicular seminoma is reported. A 48-year-old man underwent left radical nephrectomy for a renal tumor on September 4, 1991. Pathological examination revealed clear cell carcinoma with no capsular penetration. There was no evidence of distant metastases. During postoperative follow-up, he noticed a painless left testicular induration in July, 1994. Serum human chorionic gonadotropin beta subunit as a tumor marker was elevated. Left radical orchiectomy was performed on October 17, 1994. Pathological examination revealed an anaplastic seminoma localized within the testis. Chest X-ray was normal and CT of the abdomen demonstrated no evidence of retroperitoneal lymphadenopathy. The patient was diagnosed as clinical stage I left testicular seminoma. He was free of disease 8 months postoperatively. Including our case, 15 cases of clinically detected double cancers of renal cell carcinoma and testicular germ cell tumor have been reported worldwide. This is the first case of a metachronous presentation of these two cancer types preceded by renal cell carcinoma.

Carcinoma, Renal Cell↗

PubMed1995

[Halothane concentration inhaled by anesthesiologists during anesthesia through face masks].

Exposure to low concentrations of anesthetics is still an important medical concern. We measured halothane concentrations in air inspired by anesthesiologists practicing inhalational anesthesia through face masks (10 cases, 200 sampling points). Halothane concentrations were 0 to 15 ppm (mean 4.89 ppm), higher than the safety level recommended by National Institute for Occupational Safety and Health (NISOH). However, these concentrations were clearly low in a room air-conditioned with vertical laminar flow providing total air exchange rate of 30 per hour (0.55 +/- 0.53 ppm, n = 40) compared to those in the rooms with horizontal laminar flow of 25 (5.98 +/- 3.80 ppm, n = 80, P < 0.001). These observations indicate the importance of ventilation systems of operating rooms for avoiding anesthetic gas exposure to anesthesiologists during inhalational anesthesia through face masks.

Anesthesia, Inhalation↗

PubMed1995

Relative zinc-binding capacity of metallothionein in hepatic cytosols of zinc-injected rats.

In order to determine the zinc-binding capacity of metallothionein in hepatic cytosols of zinc-injected rats, we examined the relationship between zinc contents in cytosols and metallothionein fraction in rat livers. Each rat was injected intraperitoneally once with 0.9 % NaCl or zinc (10, 20, 40 or 60 mg zinc/kg b.w.) and was killed 14 h after injection. The distribution profiles of the hepatic cytosols of zinc-injected rats on a Sephadex G-75 column showed that the increased zinc was attributable to the metallothionein and high molecular weight proteins. Our results demonstrated that 63% of the increased zinc in hepatic cytosols of zinc-injected rats was bound to metallothionein and that 23% of the increased zinc was bound to high molecular weight proteins. These results suggest that the mechanisms of zinc accumulation in rat liver are different from those of cadmium accumulation.

Animals↗

PubMed1995

Relative zinc-binding capacity of metallothionein: studies in renal cytosols from zinc-injected rats.

Each rat was injected intraperitoneally once with 0.9% NaCl or zinc (10, 20, 40, or 60 mg zinc/kg b.w.). The zinc content in kidney reached a maximum level of approx. 50 microgram/g kidney, corresponding to a dose (40 mg zinc/kg b.w.). The distribution profiles of the renal cytosols of zinc-injected rats on a Sephadex G-75 column showed that most of the increased zinc was attributable to metallothionein. There was a linear relationship between the zinc contents in cytosol and metallothionein. Our results demonstrated that there was a limit of zinc accumulation in kidneys of zinc-injected rats and that 57% of the increased zinc in renal cytosols was bound to metallothionein. Our results suggest that the role of metallothionein in zinc accumulation in the kidney is similar to that of zinc accumulation in liver.

Animals↗

PubMed1995

[Hepatitis B].

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Diagnosis, Differential↗

PubMed1995

[Potassium channel dysfunction at the lesion site in multifocal motor neuropathy as revealed by threshold electrotonus].

Multifocal motor neuropathy presents as a treatable muscular atrophy and is characterized by persistent conduction block and fasciculations or myokymia. Although the pathological findings at the lesion site revealed perivascular demyelination with little evidence of remyelination, the mechanism of conduction block is still unknown. We explored the threshold electrotonus, which registers membrane potential changes through threshold variation, at the lesion site. The findings were consistent with focal potassium channel dysfunction, with some evidence of depolarization block. The disrupted blood-nerve barrier and lack of Schwann cell-mediated extracellular potassium regulation may predispose the membrane depolarization, thereby accounting for the conduction block and fasciculations. Sensory nerve fibers are known to have more inward rectifiers, which take up the extracellular potassium, than motor fibers, and this may explain the sparing of these fibers.

Humans↗