Biomedical subjects
Publications and source records attributed to K Taguchi.
Two identical LVADs were equipped with different types of heart valve prostheses (Björk-Shiley disk and PU-valves) and tested in two simultaneous calf experiments for 28 days each. Noise levels, accelerations of the pump housing and thrombus formation were higher for the mechanical valve pump.
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Nitrogen dioxide (NO2) and sulphur dioxide (SO2) in air were sampled by the use of a Sep-Pak C18 cartridge impregnated with triethanolamine-potassium hydroxide. The trapped NO2 and SO2 were eluted with a 8 mM sodium carbonate-3 mM sodium hydrogencarbonate solution and simultaneously determined by ion chromatography. In the active sampling mode, NO2 was determined with 5.2% relative standard deviation at 95 ppb and SO2 was determined with 2.4-5.3% relative standard deviation at 54-184 ppb. The recoveries were 85-98% for NO2 and 91-105% for SO2. In the passive sampling mode, the average concentrations of NO2 and SO2 were determined with 2.4-6.8 and 2.8-7.9% relative standard deviation, respectively, at atmospheric levels for 6-24 days.
A 55-year-old woman with sarcoidosis developed hyperparathyroidism that was associated with fluctuating serum calcium levels. Ultrasonography and a computed tomography (CT) scan of the neck demonstrated a cystic lesion in the lower posterior area of the left thyroid lobe. Histological examination after subsequent surgery revealed sarcoid granulomas within a parathyroid adenoma. The pathogenesis of this rare association is discussed.
The immunohistochemical localization of the alpha and beta subunits of S-100 protein in 4 cases of the malignant Schwannomas arising from von Recklinghausen's disease was investigated by the indirect immunoperoxidase method. S-100 alpha-positive cells were few in presumably normal peripheral nerves, moderate in numbers in plexiform neurofibromas and numerous in malignant Schwannomas. In contrast, S-100 beta immunoreactivity, abundantly detected in normal peripheral nerves and plexiform neurofibromas, was completely negative in all of 4 cases of malignant Schwannoma. In addition, double immunostaining method for both subunits revealed their simultaneous existence in cells in the normal nerves and neurofibroma. These results suggest that malignant change of Schwann cells convert their subunit composition of S-100 protein from beta to alpha in these malignant cells. Although the mechanisms for the proportional conversion of the subunits are as yet undetermined, the immunoreactivity of S-100 alpha subunit may be a useful marker for Schwannoma in malignancy.
Partially N-acetylated chitosan was covalently immobilized onto polymeric film surfaces using the photosensitive hetero-bifunctional crosslinking reagent, methyl 4-azidobenzoimidate, which was previously attached to the chitosan by the reaction between an imidoester group of the reagent and a free amino group of the chitosan. The grafting was accomplished by irradiating with ultraviolet light the modified chitosan being coated on the film surfaces to photolysis arylazide groups, thus crosslinking the chitosan and the underlying substrate polymer together. For ultraviolet absorption and infrared spectroscopy, the irradiation time of 3 min was found to be sufficient for the photolysis of the azide group. The thickness of the immobilized chitosan layer was estimated to be of the order of 30-150 nm using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The chitosan molecules immobilized on the surfaces could be chemically modified by several reagents and also treated with a heparin solution to form a polyelectrolyte complex on the surface. The ionically bound heparin was partially released into a phosphate buffer solution.
A case of malignant Brenner tumor with peritoneal metastasis in a 67-year-old woman was reported. The multilocular cystic tumor of right ovary was 420 g in weight, and their cystic walls were covered with multilayered tumor cells showing papillary pattern very frequently. The tumor was histologically transitional cell carcinoma with occasional glandular structures but no squamous differentiation corresponding to grade 2 or 3 urinary bladder carcinoma. The pattern of benign Brenner tumor was not identified, but there was some area of proliferating Brenner tumor. Immunohistochemically, carcinoembryonic antigen was detected in several tumor cells, especially in the intercellular spaces among them, and cytokeratin was detected only in some tumor cells. Ultrastructurally, the malignant Brenner tumor shared many common features with the benign one and also bladder tumor. Intercellular spaces with microvilli were frequently found and thought to be important for diagnosis. The morphologic criteria of this rare tumor are discussed.
In order to clarify the differentiation of medulloblastomas, the authors studied on the morphological features and immunohistochemical expression of glial fibrillary acidic protein (GFAP), S-100 protein, neuron-specific enolase (NSE), and neurofilament (NF) in 31 medulloblastomas. GFAP was detected only in a small number of tumor cells of 5 medulloblastomas; S-100 protein in both small tumor cells and some so-called spongioblastic cells in 16 medulloblastomas; NSE in the more abundant tumor cells and the matrix in 28 medulloblastomas; NF in a few tumor cells of 12 medulloblastomas; GFAP and NF in 2 medulloblastomas, but each of them in different tumor cells. These results suggest that medulloblastomas have a capacity of differentiation along neuronal and/or glial lines. The conventional morphological markers of differentiation in medulloblastomas such as spongioblastic cells and Homer Wright rosettes were not necessarily compatible with expression of immunohistochemical markers such as GFAP or NF. NSE and S-100 protein seem less valuable markers of differentiation because they were detected in both neuronal and glial elements. But NSE, which was observed in most medulloblastomas, might have a value as a marker for medulloblastomas.
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The effects of ingested Al on the essential metals were investigated using mice. Animals were divided into 4 groups: 1) Control, 2) Al, 3) EtOH and 4) Al+EtOH groups. Powdered commercial food, containing 1.26% P, 1.36% Ca, 70ppm Zn, 15ppm Cu, 200ppm Fe and 3.1ppm Al, was used to prepare the diets. For Al-treated groups, Al(AlCl3) was added to powdered food at a concentration of 4000ppm. The co-existing effect of EtOH which is known to affect the essential metals, was also investigated as a possible modulater of Al toxicity at a concentration of 5% for 22 days, followed by 10% for 36 days in the drinking water. After 58 days feeding with food containing Al and / or EtOH containing water, the Al effects on serum and femur P and Ca were found to be slight except for a significant decrease of serum P concentration in the Al+EtOH group. In this group, femur weight was less and femur Al concentration was more compared with the Al group. The effects on Fe and Cu were little. We observed a significant decrease of serum Zn concentration with 4000ppm Al diet in both the Al-treated groups. The fact that serum ALPase activity, a Zn enzyme, increased in disregard of a significant decrease of serum Zn concentration suggested the enzyme release from injures tissues. It is noticeable that a significant decrease of serum Zn concentration was observed when dietary Zn was sufficient. It is reported that the dietary intake of Zn is under the recommended allowance for many people. Since Al compounds are widely used as drugs, food additives and a conditioned latent Zn deficiency is rather common in human diseases, the effects of Al on the Zn metabolism are to be investigated further.
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A rare case of pseudolymphoma of the retroperitoneum is described; differential diagnosis is discussed using radiological methods.
The purpose of the present paper is to investigate the effect of morphine on the serotonergic system through an analysis of electrochemical signals in the spinal cord of the anesthetized cat. Electrochemical signals showed a peak of 5-hydroxyindole at 280-300 mV, and were highest at a depth of 1500-2500 microns in the dorsal horn of the spinal cord. Electrical stimulation of the nucleus raphe magnus (NRM) produced an increase in the electrochemical signal. Five-hydroxytryptophan (25 mg/kg, i.v.) also enhanced the signal remarkably. Both systemic administration of morphine (1-2 mg/kg, i.v.) and microinjection (5 and 10 micrograms/microliter) of morphine into the NRM increased the signal. In conclusion, it is suggested that morphine-induced enhancement of the peak of 5-hydroxyindole contributes to the activity of the serotonergic system in the cat spinal cord.
A rare case of hamartoma of the left cerebellar hemisphere was recognized in an 11-month-old male infant whose mother had a history of unspecified medication in the early gestational period and had a difficult delivery. A notably large head and marked developmental disorders, like hypotonic cerebral palsy, were observed soon after birth. A computed tomogram revealed an iso-minimally enhanced large mass in the left cerebellar hemisphere, which deformed the fourth ventricle and compressed the right cerebellum, as well as moderate cerebral atrophy. Histologically, the border between the cerebellar cortex and this tumor was not apparent. The main tumor, located in the cerebellar white matter, was composed of numerous scattered Purkinje cell-like neurons and glial cells surrounded by abundant GFAP-positive matrix. The small part of the tumor, located near the choroid plexus, was composed of intensely proliferated capillaries such as in capillary hemangioma, and numerous fibrocytes, which were intermingled with several large Purkinje cell-like neurons and some with several large Purkinje cell-like neurons and some GFAP-positive glial cells. The cerebellar cortex showed a thin molecular layer with some residual external granular cells, a marked decrease of Purkinje cells and a moderate decrease in the internal granular layer, in which large Purkinje cell-like neurons were scattered. Purkinje cells and large Purkinje cell-like neurons scattered in the internal granular layer, cerebellar white matter and choroid plexus showed positive immunoreactivity for anti-Leu-4 monoclonal antibody, which is known to be a marker for Purkinje cells.(ABSTRACT TRUNCATED AT 250 WORDS)
A case of titanium dioxide pneumoconiosis accompanied by lung cancer is reported. The patient was a fifty-three-year-old male, who was engaged in packing titanium dioxide for about thirteen years. At autopsy, a papillary adenocarcinoma was located in the right lung. Titanium was diffusely deposited in the lung and was engulfed by macrophages in the interstitium and alveolar spaces. Slight fibrosis of the interstitium around bronchioles and vessels was noticed as an effect of titanium deposition.
The efficacy of cimetidine in the prevention of gastrointestinal haemorrhage in a general intensive care unit was evaluated in 221 patients by a placebo controlled double blind randomised study. Criteria for bleeding were (i) haematemesis or gastric aspirate greater than 50 ml fresh blood, (ii) melaena or fresh blood per rectum with an upper source verified by endoscopy if the gastric aspirate was clear, (iii) a fall in haemoglobin level greater than 2 g/dl in a 24 hour period associated with either 4+ occult blood in stools, or coffee ground gastric drainage of at least 100 ml. The drug and placebo groups were similar for age, sex, duration of study and risk factors. One hundred and fourteen received cimetidine and 107 placebo. Only 8% of the patients bled with no significant difference between the two groups (6/114 cimetidine, 11/107 placebo; p = 0.16). There was no correlation between the frequency of bleeding and either the number of risk factors per patient or the duration of intensive care unit stay. Thirteen patients died in each study group, resulting in overall mortality of 12%. The low incidence of haemorrhage, the lack of statistical benefit from cimetidine and the similar mortality all argue against the routine use of this drug in intensive care unit patients.