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Biomedical subjects

T Miwa

Publications and source records attributed to T Miwa.

At least 235 records · Page 13Linked to original sources
PubMed1991

Abscessed leiomyosarcoma of the ileum.

A-49-year-old man was admitted because of a lower abdominal mass. During the five days prior to admission, he had noted fever and lower abdominal pain. Palpation of the abdomen revealed a tender mass, 10 cm in diameter, in the suprapubic region. An x-ray revealed an irregular collection of gas, 9 cm in diameter, in the pelvic cavity, which appeared as a mirror image when the patient was upright. Based on the physical finding and the results of a barium enema, abdominal CT, MRI, and small intestine imaging, a diagnosis of leiomyosarcoma of the ileum was made. Excision of the tumor and part of the small intestine was performed. A saccular tumor, 11 x 6 x 5 cm, was found 1.0 m from the cecum and growing out of the wall of the ileum. A large amount of pus was found inside the cavity. The pathological diagnosis was leiomyosarcoma.

Abscess↗
PubMed1990

Rapid method for construction of yeast artificial chromosome human DNA libraries involving the trapping of cells in agarose films.

A simple method for the molecular cloning of fragments of more than one hundred kilobase pairs of exogenous DNA, by the encapsulation of cells in agarose beads, was reported previously for the construction of a human genomic DNA library in a yeast artificial chromosome (YAC) vector (in situ YAC construction) [1]. The efficiency of this procedure is impaired by the step in which agarose beads that contain human DNA fragments are melted before transformation. The incomplete solubility of the ligated human DNA fragment-YAC vector often results in lower than desirable frequencies of transformation. To overcome this problem we have developed a new improved method that involves use of an agarose film. The technical manipulations involved in the construction of clones of very large segments of human DNA are discussed.

Chromosomes↗
PubMed1990

Effect of straight chain fatty acids on seizures induced by picrotoxin and pentylenetetrazole in mice.

The effects of straight chain fatty acids on seizures induced by picrotoxin and pentylenetetrazole were studied in mice. After i.p. injection capric, lauric, myristic, palmitic and stearic acid delayed the onset of picrotoxin-induced clonic convulsion in a dose-dependent manner. The survival time was also prolonged by the pretreatment with lauric, myristic, palmitic and stearic acid. However, the onset of the clonic convulsion induced by pentylenetetrazole was delayed only by lauric acid. The prolongation of the survival time was also observed only in the animals pretreated with capric and lauric acid. These results suggest that the straight chain fatty acids examined in the present study possess anticonvulsant activity in mice.

Animals↗
PubMed1990

The biochemical and ultrastructural examinations in central cholinergic damage of the rat induced by the intraperitoneal administration of AF64A.

Ethylcholine mustard aziridinium ion (AF64A), a synthesized cholinergic neurotoxin, was administered via intraperitoneal injection to the rat to study its effect on the central cholinergic nervous system. A single or consecutive daily injection of AF64A for 10 days resulted in a persistent reduction of acetylcholine (ACh) content in the several tested regions of the brain in the following order: hippocampus greater than cerebral cortex = striatum, the degree was the greatest in the hippocampus. Both resting and K(+)-stimulated release of ACh from the hippocampus were also significantly reduced 24 hr after a single injection of AF64A. Furthermore, daily injection of AF64A for 10 days induced a significant reduction of choline acetyltransferase (ChAT) activity in the homogenate obtained from the hippocampus but not from the cerebral cortex and striatum. ChAT activity in the crude synaptosomal fraction of the cerebral cortex was also significantly decreased. These results suggest that intraperitoneal administration of AF64A could induce cholinergic hypofunction more selectively in the nerve terminals. The high affinity choline uptake, which is located mainly on cholinergic nerve terminals, was not affected by the administration of AF64A. Any notable changes of ultrastructure in the cholinergic nerve terminals after the administration were not observed in all three regions examined. The present findings suggested that intraperitoneal administration of AF64A induces a specific damage of cholinergic nerve terminals by inhibiting ChAT activity. The cholinergic damage was most prominent in the hippocampus.

Acetylcholine↗
PubMed1990

The effects of prenatal protein-energy malnutrition on ossification of fetal rat bones: a biochemical study.

In fetal rats whose dams were fed a low-protein diet, 35S sulfate uptake into the growth plate of the long bone and rib was higher than in the control group. The elution pattern of guanidine-HCl extract in gel chromatography revealed that the malnourished group had more high molecular weight proteoglycans in the dissociative condition and a larger aggregated portion in the associative condition than did the control group; however, the same chondroitin-sulfate chain size existed. Calcium content did not differ in both groups. Aggregated proteoglycan or a high molecular weight proteoglycan that existed in the malnourished group probably played an inhibitory role in calcification. Prenatal protein-energy malnutrition may delay the change of proteoglycan character, which could affect mineralization of fetal bones.

Animals↗
PubMed1990

[Evaluation of turnover of olfactory epithelium in mice by using anti-BrdU monoclonal antibody].

Among nerve cells of vertebrates, the olfactory elements are uncommon in their capacity to turnover and to be replaced after injury. An autoradiographical and morphological observation has shown that degenerated olfactory nerve cells are reconstituted by a new population of neurons which originate from basal cells. However, an autoradiographic method requires a special isotope institute and it takes a long time for the final specimen to observe. Recently, a rapid technique without the radioisotope has been alternatively developed in which a thymidine analogue, 5-bromo-2'-deoxyuridine (BrdU), is incorporated into replicating DNA and subsequently localized using a specific monoclonal antibody. In the present study, cell dynamics of olfactory mucosa in mice were investigated by means of immunohistological technique. The results were as follows. 1. The labelled elements were concentrated at the basal layer of the epithelium, which were observed 5 hrs after the first injection of BrdU. 2. At 15 days after administration of BrdU, the labelled elements were located in the mid-layer of the epithelium, where can be recognized as the compartment of nerve cells. 3. After 30 days, the labelled cells disappeared from the epithelium. It indicates that the period of turnover in the olfactory epithelium of mice is within 30 days. 4. Fifteen days after axotomy of the olfactory nerves, two stained patterns which were numerously or sparsely labelled regions were observed. The former is considered that immature neurons predominantly exist, and the latter is the area which mature neurons abundantly locate. It is considered that this immunohistological approach is useful for the observation of the turnover of the olfactory epithelium.

Animals↗
PubMed1990

[Studies on the contractile mechanism of isolated gastric smooth muscle cells of guinea pig--investigation of the histamine receptor].

Investigation about the histamine receptors of gastric smooth muscle cells was done using isolated gastric smooth muscle cells of guinea pig. Isolated gastric smooth muscle cells were prepared from the stomach of guinea pig by percoll density gradient centrifugation after enzymatic digestion with collagenase and dyspase. Contraction of the cells was determined by image of phase-contrast microscopy and digitizer and expressed as the mean per cent of control in cell axis length. The concentration of intracellular Ca2+ ([Ca2+]i) was measured with the calcium-sensitive dye fura-2. Tested drugs were added to the incubation medium containing 2 mM CaCl2. Both contractile response and [Ca2+]i increased following histamine stimulation in a dose-dependent manner from 10(-7) to 10(-4) M, and those peaks were obtained in application of 10(-4) M pyridylethylamine, a H1 receptor agonist, made an increase in [Ca2+]i as much as 10(-4) M histamine. But 10(-4) M dymaprit, a H2 receptor agonist, made only small increase in [Ca2+]i, whose value was similar to that in application of only 2 mM CaCl2. 10(-4) M pyrilamine, a H1 receptor antagonist, inhibited the response to 10(-4) M histamine, and the value was similar to that in application of only 2 mM CaCl2. Cimetidine, a H2 receptor antagonist, did not inhibit the response to 10(-4) M histamine stimulation at all. From those results it is concluded that the action of histamine to the gastric smooth muscle cells of guinea pig may be mediated through H1 receptor, but not through H2 receptor.

Animals↗
PubMed1990

[Tuberculosis sequelae: secondary fungal infections].

The antibody activities against Aspergillus fumigatus, Cryptococcus neoformans and Coccidioides immmitis by complement fixation (CF) were examined for active and cured pulmonary tuberculosis in 1985, and against Aspergillus fumigatus and Candida albicans by indirect hemagglutination (IHA) and counterimmunoelectrophoresis (CIE) in 1986. The antibody activity against Aspergillus by CF was positive in 8.6% of the sera and negative against Cryptococcus, and Coccidioides. The IHA results were positive in 2.9% against Aspergillus and in 44.9% against Candida. The CIE results were positive in 19.5% against Aspergillus and in 16.3% against Candida. Based on chest X-ray films, the development of pulmonary candidiasis was non-specific but that of pulmonary aspergilloma in tuberculous cavities was specific. Before aspergillomas were formed, the tuberculous cavities had become thin-walled. Then the cavities increased or decreased in size. It is postulated that the cavity has tension when check-valved by mycetome in the drainage bronchus, and becomes smaller or distinct when ventilated inadequately. In cases cavities do not change in size due to intracavitary proliferation of Aspergillus, the wall of cavity is rough, prominent, or opaque.

Adult↗
PubMed1990

Isolation of guinea pig gastric smooth muscle cells.

A method of isolating guinea pig gastric smooth muscle cells was established in order to investigate gastric contractile mechanisms at the cellular level. Strips of gastric muscle were digested enzymatically with collagenase and dispase, and the smooth muscle cells isolated on a percoll density gradient, with a purity of 80-90%. The muscle cells were over 90% viable and demonstrated a remarkable contractile response to carbachol stimulation in a dose-dependent manner, from 10(-7) M to 10(-4) M. Intracellular Ca2+ concentration following carbachol stimulation was monitored, since Ca2+ is essential to the contractile process, and it was found to increase almost in parallel with contraction. These results suggest that the measurement of intracellular Ca2+ concentration is useful for analyzing the contractile mechanism of isolated smooth muscle cells.

Animals↗
PubMed1990

A combination of Laserthermia and chemotherapy for the treatment human gastric cancers transplanted into nude mice.

The effects of Laserthermia plus chemotherapy on a human gastric cancer transplanted into nude mice was investigated. Three different treatment regimes were tested. The relative tumor growth rate according to the Battele Columbus Laboratories protocol, was as follows. 5-FU chemotherapy, 54%; Laserthermia, 31%; and combined treatment with 5-FU and Laserthermia, 21%. The greatest degree of tumor regression was achieved in the combined therapy group. It is suggested that the combination therapy of Laserthermia plus antitumor agents may be useful in the treatment of gastric cancer in humans.

Adenocarcinoma↗
PubMed1990

[Wallenberg's syndrome caused by a brain tumor--a case report and literature review].

we report a patient with Wallenberg's syndrome caused by glioma of the lateral medulla oblongata, and review the literature for Wallenberg's syndrome associated with neoplastic disease. A 46-year-old man was admitted because of progressive dysphagia and vertigo. Neurological examination revealed atypical symptoms and signs of Wallenberg's syndrome on the right side, hypalgesia on the second and third divisions of the left trigeminal nerve, paresis of the right palate and uvula, and ataxia of the right extremities. Although CT showed no abnormality in the posterior fossa, MRI demonstrated a mass with abnormal signal intensities in the right dorsolateral portion of the medulla. Biopsy specimens showed astrocytoma (grade III). Based on the present case and a review of 10 previously reported cases of Wallenberg's syndrome caused by neoplastic disease, the clinical features of this syndrome are characterized by gradual development and steady progression of symptoms, non-classical or atypical symptomatology, numerous additional symptoms and signs depending on the site and size of tumors, and poor prognosis.

Brain Neoplasms↗
PubMed1990

[Intracranial hematoma accompanying bleeding tendency: therapeutic practice and analysis of literature].

Therapies and prognoses covering fifteen cases of intracranial hematoma (ICrH) accompanying various types of bleeding tendency (BTD) were studied along with a secondary analysis of the pertinent references. Fifteen cases were divided into two groups, Group A comprising 11 cases of ICrH accompanying primary BTD, and Group B comprising four cases of ICrH accompanying secondary BTD caused by various underlying diseases. Group A included four cases of hemophilia A (Hp-A), two cases of factor XIII deficiency (FXIII-d), three cases of thrombocytopenia (Th-p) and two cases of vitamin K deficiency (VK-d). The four cases of Hp-A responded favorably, with good prognoses, to a supplementary therapy alone. This result was endorsed by the development of therapy as documented in the references. The combined five cases of FXIII-d and Th-p tended without exception, to show good prognoses in the wake of a combination therapy of supplementary treatment and surgical procedure. As regards FXIII-d, there was an inter-reference difference in supplementary doses. Many references shared the view that splenectomy was essential to the treatment of Th-p in general, and idiopathic thrombocytopenic purpura in particular. The current study also suggested that gammaglobulin in large doses would serve as an effective therapy. The two cases of VK-d suffered from a serious degree of lingering neurologic manifestations, although their lives were saved. Even though there is an established therapy for it, VK-d was found to be a problem with poor functional prognosis showing the importance of the preventive approach. Group B was classified into the acute type and the subacute type depending on the rate of pathologic development. As underlying diseases DIC and myelofibrosis due to acute myeloblastic leukemia, and Th-p due to aplastic anemia were noted in two cases in each group. Of these, two cases of the subacute type were able to be saved, while two cases of the acute type followed poor prognostic courses resulting, eventually, in death. The following were found to be responsible fatal factors: 1) causes of BTD which involved both mechanisms of coagulation and hemostasis, 2) non-removal of the underlying disease, in which case supplementary therapy tended to be futile, and 3) the underlying disease per se as a danger to the life of the patient. In conclusion, therapeutic rationale and prognosis in ICrH accompanying primary type of BTD will benefit from the implementation of an adequate augmentative therapy as in the ordinary type of ICrH.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Stable isotope 15N-urea and clinical research in nephrology.

Stable isotope 15N-compound, 15N-urea, is useful marker to investigate nitrogen metabolism in clinical nephrology, particularly in chronic renal failure or dialysis. 15N-urea incorporation into plasma albumin in addition to plasma 15N disappearance was studied in 6 patients with endstage chronic renal failure. As a result, only minor fraction of administered 15N-urea was incorporated into albumin in this study. In addition, it was also confirmed that high energy diet may promote protein synthesis through 15N incorporation to plasma amino acids, such as alanine, in these patients with low protein meal. Therefore, administration of 15N-compound to human subjects may contribute to provide us the important informations on nitrogen metabolism. For instance, urea kinetics are described in the endstage chronic renal failure in this review. However, less expensive 15N-compounds should be provided and more simple but accurate measurement of 15N activity should be developed for the further clinical application of the stable isotope.

Adult↗
PubMed1990

[Management in sequelae of pulmonary tuberculosis (chronic respiratory failure)].

1. The high risk groups for chronic respiratory failure due to pulmonary tuberculosis were identified based on the chest X-ray sketches on the TB Registration Cards in a health center. They showed 10.8-14.8% of mortality which was highly related to respiratory failure (ca 64%). To prevent developing acute exacerbation, they were educated collectively in daily care at the health center and were introduced to medical services immediately upon demand. 2. The 248 patients suffering from chronic respiratory failure or pre-respiratory failure due to pulmonary tuberculosis were divided into three groups; A: 83 cases without past history of admission due to acute exacerbation, B: 138 cases with past history of short term (under 1 year) admission, C: 27 cases with past history of long term (over 1 year) admission. We analyzed these cases by background, symptoms, pulmonary function tests, therapeutic effects, and prognosis retrospectively. The frequency of exertional dyspnea, O2 demand, acute exacerbation, and artificial ventilation increased in the order A-B-C.

Aged↗
PubMed1990

[Coexistence of cyst and tumor in the same kidney: a case report].

A case of renal cyst associated with renal tumor is presented herein. A 40-year-old male patient visited our outpatient clinic for left renal cyst which had been found by ultrasonography on routine clinical examination. CT scan demonstrated an irregular area in the cyst wall measuring about 2 cm in thickness which showed enhancement of density with contrast medium. Magnetic resonance imaging (MRI) also demonstrated a round mass with abnormal signal on the cyst wall, protruding into the cyst cavity. Transabdominal radical nephrectomy was performed on 13 July 1987, and to the resected kidney was attached a cyst measuring 7 cm in diameter in the lower pole. Grossly, the cyst contained amorphous red-brown material which turned out to be old blood clots and the wall harbored a tumor (3.0 x 2.5 cm). Histologically, the tumor was renal cell carcinoma, the surface of which was covered with necrotic tissue. The coexistence of renal cyst and tumor is rare and 62 cases were collected from the Japanese literature including our case, and discussion was made in relation to the etiological factors.

Adult↗
PubMed1990

The effect of oxygen tension on collagen synthesis and calcium uptake in newborn rats' calvaria in vitro.

Using newborn rat calvaria, we determined the effects of oxygen tension on bone cell metabolism in vitro. Halved calvaria were incubated in medium either in air or after flushing nitrogen or oxygen and studied for collagen synthesis, calcium uptake, and DNA content. The percentages of DNA content, radioactive proline count in mg of bone tissue, and radioactive proline count combined with counts of medium and bone tissue in the nitrogen-exposed group were less than those of their pair-matched controls. Percent calcium counts per DNA and calcium uptake per mg of tissue were greater in the nitrogen-exposed group than in the pair-matched controls. In contrast, no difference was found in any measurements in the oxygen-exposed group compared with controls. It is concluded that collagen synthesis, in contrast to proline uptake, is not affected by low oxygen, whereas calcium uptake is greatly enhanced. Furthermore, low oxygen tension exerts a greater effect on bone cell metabolism than does the hyperoxic condition.

Animals↗