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Biomedical subjects

T Shimada

Publications and source records attributed to T Shimada.

At least 613 records · Page 34Linked to original sources
PubMed1993

Correlation between metabolic and histopathological changes in the myocardium of the KK mouse. Effect of diltiazem on the diabetic heart.

Serial changes in myocardial parameters related to non-insulin-dependent diabetes mellitus were investigated in DDY mice (control), untreated KK mice, and KK mice treated with diltiazem (150 micrograms/kg body weight, KKd1: or 300 micrograms/kg body weight diltiazem, KKd2). The isozyme ratio of lactate dehydrogenase (LDH) [(LDH1+LDH2)/(LDH4+LDH5)] was used as an index of aerobic metabolism of myocardial tissue. Mean blood sugar levels did not vary between 5 weeks and 30 weeks of age, ranging from 108 (range 60-198) mg/dl in DDY mice to 170 (range 110-282) mg/dl in KK mice. The ratio of heart weight to body weight was larger in KK mice than in DDY mice at 20 weeks of age, but was unaffected by diltiazem treatment. The LDH isozyme ratio showed that DDY mice were in an aerobic state at 15 and 20 weeks of age, while KK mice were in an anaerobic state at 10 and 15 weeks of age. The KKd1 and KKd2 groups exhibited the same LDH isozyme ratios as untreated KK mice; diltiazem had no effect on the LDH isozyme ratio at 20 and 30 weeks of age. The mean diameter of myocytes was increased in KK mice but diltiazem had no effect on this parameter. Interstitial fibrotic changes appeared at 15 weeks in untreated KK mice and progressed with age. These changes were completely suppressed in KK mice treated with diltiazem. These results suggest that hyperglycemia induces an anaerobic state in heart muscle, leading to muscle hypertrophy, degeneration, and fibrosis and that calcium antagonists may suppress these pathological changes.

Anaerobiosis↗
PubMed1993

Functional morphology of the lymphatic system in the monkey diaphragm.

A morphological study of the lymphatic system in the diaphragm of adult Japanese monkeys was carried out using intraperitoneal injection with India ink, light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) techniques. For SEM examination of the subperitoneal connective tissue, the peritoneal mesothelium was stripped by either the NaOH/sonication microdissection techniques or the NaOH digestion method. Light microscopy of 1 micron Epon sections and TEM of thin sections demonstrated that lymphatic capillaries were distributed in the subperitoneal connective tissue of the muscular and tendinous portions. Gaps (stomata) between neighboring cells of the peritoneal mesothelium were occasionally encountered. In SEM observations, stomata with oval shapes and various sizes were abundantly seen in the peritoneal mesothelium, but were absent from the pleural mesothelium. It deserves particular note that a large number of foramina were detected in the subperitoneal connective tissue. The cluster of the foramina was similar in appearance to the "macula cribriformis" depicted by KIHARA (1956). Carbon particles injected into the monkey peritoneal cavity passed through the peritoneal stomata and then the macula cribriformis, ultimately to enter the lymphatic capillaries. This paper also discusses the functional implication of the lymphatic system in the diaphragm.

Animals↗
PubMed1993

Serial bronchoalveolar lavage studies in a patient with intra-alveolar fibrosis following Legionnaires' disease.

A 48-year-old male developed acute respiratory failure owing to Legionnaires' disease (LD). Antibiotic treatment including erythromycin and rifampicin was not effective, thus transbronchial lung biopsy was performed. The histological examination of the lung showed intra-alveolar fibrosis. Corticosteroid therapy was begun and he responded well with definite clinical improvement. Bronchoalveolar lavage (BAL) was performed three times in the following year. The first BAL showed an increase of lymphocytes which then decreased significantly in the following studies. This case report thus demonstrates the importance of lung biopsy of protracted LD and the usefulness of BAL in the assessment of corticosteroid therapy.

Bronchoalveolar Lavage Fluid↗
PubMed1993

Spontaneous submucosal dissection of the esophagus.

A 41-year-old woman was found to have had spontaneous submucosal dissection of the esophagus by esophagoscopy. Food ingestion was postulated to have been an initiating factor in this instance. Conservative therapy was sufficient in this case. Patients who complain of sore throat with retrosternal pain and an obstructed sensation on swallowing or mild hematemesis should be examined by esophagoscopy for evidence of this disorder.

Adult↗
PubMed1993

[Present status and future prospects of human gene therapy].

Gene therapy is defined as the treatment of diseases by the transfer of genes into cells. This concept originally emerged as the definitive therapy for genetic disease. However, acquired diseases such as cancer and AIDS are now being considered as its potential targets. The first clinical trial of human gene therapy was in 1990 at the NIH in a 4 year old girl with fatal severe combined immunodeficiency caused by adenosine deaminase deficiency. Blood transfusion with genetically corrected lymphocytes resulted in significant improvement of the function of her immune system. The patient was discharged from hospital and is attending a public school. Immunotherapy for cancer using tumor cells transduced with genes for various cytokines and major histocompatibility antigens (tumor vaccine) has also been initiated at many research hospitals. In addition, gene therapy protocols targeting familial hypercholesterolemia, hemophilia B, cystic fibrosis are underway. Currently, more than 50 clinical protocols have been approved by the Recombinant DNA Advisory Committee at the NIH, and more than 100 patients have already been treated by this innovative therapeutic strategy.

Child, Preschool↗
PubMed1993

Three-dimensional visualization of the aorta and elastic cartilage after removal of extracellular ground substance with a modified NaOH maceration method.

A modified NaOH maceration method for removing extracellular ground substance was applied to scanning electron microscopic (SEM) studies of the mammalian aorta and elastic cartilage. Fixed tissues were freeze-fractured in liquid nitrogen and then immersed in 2N NaOH solution for 4-6 hr at room temperature. Since this method selectively digested proteoglycans, cellular and fibrous elements were observable clearly under the SEM. The elastic laminae of smooth muscle cells of the aortic tunica media were concealed by fine collagen fibrils, while chondrocytes in the elastic cartilage were encapsulated by a dense network of fine collagen fibrils and branching elastin fibers.

Animals↗
PubMed1993

[Pure red cell aplasia complicated with polyarthritis, angitis, and acute renal failure].

A case of pure red cell aplasia (PRCA) with various complications polyarthritis, angitis, acute renal failure and DIC was successfully treated with steroid pulse therapy was described. A 55-year-old woman was hospitalized with a 9-month of intermittent but progressive joint pain, morning stiffness, general fatigue, and fever. Her initial laboratory evaluation revealed a hemoglobin of 4.4 g/dl and absence of reticulocyte. Her bone marrow aspirate showed no erythroblast which was compatible with a diagnosis of PRCA. Marked leukocytosis and thrombocytosis, positive antinuclear antigen, elevation of gammaglobulin and C-reactive protein and the presence of polyarthritis and angitis which was confirmed by renal angiography, indicated an underlying autoimmune disorders. Steroid pulse therapy was administered at 500 mg/day for 3 days, resulting in the complete response in both red cell aplasia and above findings. PRCA is known to be associated with systemic lupus erythematosus and rheumatoid arthritis very rarely, but this case did not fulfill the criteria of known collagen diseases, and there is no previous report representing PRCA with various complications such as polyarthritis, angitis and acute renal failure. This case may help us to understand more about the relationship between PRCA and autoimmune disorders.

Acute Kidney Injury↗
PubMed1993

[A resected case of well-differentiated adenocarcinoma simulating fetal lung tubules which is a variant of pulmonary blastoma].

A case of well-differentiated adenocarcinoma simulating fetal lung tubules which is a variant of pulmonary blastoma is reported. A 31-year-old female with an abnormal shadow in the right upper lung field detected by chest X-P during a follow-up for sarcoidosis during pregnancy underwent right upper lobectomy. Post operative histological diagnosis was well-differentiated adenocarcinoma simulating fetal lung tubules. This tumor might be a variant of pulmonary blastoma lacking the sarcomatous features and showing one-sided development of the epithelial component. However, it has been reported by various names, and classifications of pulmonary blastoma differed slightly depending on the reporter. There are also some discrepancies in the clinical course and prognosis of the tumor. Therefore it is considered that further examination of this tumor is necessary.

Adenocarcinoma↗
PubMed1993

A morphometrical study of the postnatal development of rat pancreatic islets, with special regard to the differences between Wistar and Sprague-Dawley strains.

Postnatal development of islet cells was morphometrically studied during neonatal (0, 1, 3, 5, and 7 days post partum << p.p. >>) and adult periods in Wistar and Sprague-Dawley rats, using two sensitive immunostainings, immunogold silver and protein A gold silver techniques. Nonfasted and fasted plasma glucose levels were also measured in adults. In addition, the frequency of developing type 2 diabetes was surveyed following injection of streptozotocin to neonates (2 days p.p.) of Wistar and Sprague-Dawley rats. The following results were obtained: 1) Islets grew more rapidly in Wistar than in Sprague-Dawley rats; 2) Increased percent areas of A and D cells and decreased percent area of B cells occurred during neonatal period in both Wistar and Sprague-Dawley rats; 3) Higher percent area of A cells and lower percent area of B cells were observed in Sprague-Dawley than in Wistar rats; 4) The duodenal pancreas of Wistar rats exhibited a marked neonatal increase in the percent area of pancreatic polypeptide (PP) cells and; 5) Sprague-Dawley rats were more susceptible to streptozotocin-induced type 2 diabetes, as compared with Wistar rats. An assumption is proposed that the differences in islet cell development between these rat strains are reflected in diabetes morbidity data.

Animals↗
PubMed1993

[Alterations of Lp (a) lipoprotein in patients with chronic renal failure treated by continuous ambulatory peritoneal dialysis].

Cerebrovascular and cardiovascular diseases are important predictors for survival in patients undergoing continuous ambulatory peritoneal dialysis (CAPD), and account for about half the deaths in these patients. Lipoprotein(a) [Lp(a)] is known to show high values in diabetics with proteinuria, and albuminuric renal disease. The purpose of this study was to determine Lp(a) levels and to investigate the association of Lp(a) and atherosclerotic risk factors in patients treated by CAPD. Lp(a) concentration were measured in 20 CAPD patients in the age range 31 to 83 years. Mean (+/- SD) levels of serum Lp(a) were elevated in the CAPD patients compared to age, sex matched 17 controls (49.5 +/- 27.7 vs. 15.5 +/- 12.4 mg/dl, p < 0.001). The levels of Lp(a) were significantly higher in the diabetic CAPD patients than in non-diabetics. There were significant positive correlations between serum Lp(a) concentrations and fasting blood sugar. However, when the above two groups were matched for age, sex, body mass index and FBS, Lp(a) concentrations were also significantly higher in CAPD patients than those in normal controls. We found no statistically significant correlations of Lp(a) with either age, body mass index, blood pressure, serum lipoprotein, apoprotein, glycated hemoglobin, BUN, creatinine or serum protein levels. There were no correlations between serum Lp(a) levels and albumin and LP(a) concentrations in the dialysate in all CAPD patients. Along with assessment of other known established cardiovascular risk factors such as elevated blood pressure, atherogenic abnormalities of plasma lipids and lipoproteins, and impaired glucose tolerance, we suggest that elevated levels of Lp(a) may lead to the accelerated atherosclerosis in these patients.

Apoproteins↗
PubMed1993

[Electrophysiologic analysis of the lumbosacral radiculopathy using nerve root conduction velocity (NRCV) and cauda equina action potentials (CEAP)].

Nerve root conduction velocity (NRCV) and cauda equina action potential (CEAP) have been measured to assess the severity of lumbosacral radiculopathy, the level-specific diagnosis of the symptomatic roots, and to predict the outcome. This study included 71 patients (40 males, 31 females, average age of 54 years at the time of surgery) who underwent decompressive surgery for lumbar radiculopathy. The NRCV and CEAP were directly measured during the operation. The NRCV decreased significantly with progression of radicular symptoms. The NRCV showed a marked reduction in the nerve roots of the patients with a two years or longer history of radicular symptoms; or those with compression of the nerve roots on the imaging examinations; or nerve roots that were considered to have been subjected to persistent compression over a prolonged period with severe inflammation and adhesions. Multivariative analyses suggested that the NRCV correlated closely to the postoperative neurologic recovery, and the outcome of the lumbosacral radiculopathy could be predicted to some extent by measurements of NRCV. The level-specific diagnosis of the radiculopathy could be determined when the CEAP showed a more than 30% left-right potentials difference.

Action Potentials↗
PubMed1993

[Evaluation of the right ventricular function in postoperative esophageal cancer patients].

We evaluated the right ventricular function in pre- and post-operative esophageal cancer patients who had no complications after surgery by measurement of cardiopulmonary hemodynamics, right ventricular ejection fraction (RVEF) and right ventricular end-diastolic volume index (RVEDVI) using Swan-Ganz catheter and the thermodilution technique. The measurement of RVEF, RVEDVI and other cardiopulmonary hemodynamics were performed from the preoperative day to the 3rd postoperative day. The values of RVEF were stable about 40% from preoperative day to 3rd. RVEDVI was varied at 93.6 +/- 26.3 ml/m2 (preoperative day), 83.6 +/- 15.0 ml/m2 (after surgery), 70.2 +/- 10.6 mg/m2 (morning of the 1st POD), 95.6 +/- 19.4 ml/m2 (evening of the 1st POD), 103.2 +/- 17.9 m/lm2 (morning of the 2nd POD), 1108.3 +/- 14.2 ml/m2 (evening of the 2nd POD) and 112.4 +/- 31.0 ml/m2 (morning of the 3rd POD). The values of RVEDVI on the morning of the 1st POD were statistically lower than those at other times (p < 0.05). The values of RVEDVI were not correlated with mean pulmonary arterial pressure and pulmonary arteriolar resistance which were the afterload of the right ventricle. These data suggest that the right ventricular function of the patients who underwent esophagectomy with no complication does not change and that the changes of RVEDVI are influenced by the preload of the right ventricle.

Cardiac Output↗
PubMed1993

[Interferon-alpha therapy in the myeloproliferative variants of hypereosinophilic syndrome].

Two cases of hypereosinophilic syndrome (HES) that seemed to be myeloproliferative disorders were treated with interferon-alpha (IFN-alpha). Case 1 was a 45-year-old man with HES who was unresponsive to prednisolone. Because Flaum's hematologic grading score was 8 points, he was diagnosed as a myeloproliferative variant of HES. Although his condition was well controlled by hydroxyurea (HU), cardio-pulmonary insufficiency with refractory eosinophilia developed after 4 years. Instead of HU, IFN-alpha dramatically decreased eosinophil counts, and the clinical situation has stabilized since. Case 2 was a 30-year-old man with HES whose grading score was 9 points. IFN-alpha therapy was started when an accelerated phase of neutrophil dominant with chromosomal abnormality (8 trisomy) occurred. However, he died because of no response to IFN-alpha and other chemotherapy. In both cases, studies of eosinophil colony formation revealed no excess of eosinophil colony-stimulating factor from their lymphocytes. Flaum's hematologic grading score was useful for the diagnosis of myeloproliferative variants of HES. IFN-alpha successfully induced hematologic remission in one case, and this therapy may be beneficial for these patients as a first line agent.

Adult↗
PubMed1993

[Cyclosporin for pure red cell aplasia caused rapid improvement of anemia and increase of CD4/8 ratio].

Ciclosporine (CS) caused rapid improvement of anemia and increase of CD 4/8 ratio in two patients with pure red cell aplasia (PRCA). One case was a 45 year old female who were unresponsive to steroids, plasmapheresis and high dose cyclophosphamide, and another was a 61 years old man with diabetes mellitus (DM) without any treatment for PRCA. In both cases hemoglobin increased soon after the initiation of CS and CD 4/8 ratio also rose from 0.80 to 1.47 and 1.78 to 1.98, respectively. There was no side effects to interrupt the course of the therapy. CS seems to inhibit the production of cytokines such as IL-2 and IFN-gamma, and it damages the activated suppressor/cytotoxic T cells. CS is an effective drug for not only refractory cases but the first step therapy for the untreated patients.

Anemia↗
PubMed1993

Conditioned medium factors of rabbit cranio-facial chondrocytes stimulate their own syntheses of sulfated glycosaminoglycans and DNA.

Previously, we reported methods for isolating chondrocytes from the craniofacial cartilage and culturing them in vitro. The cells actively synthesize glycosaminoglycan (GAG), a marker of the differentiated phenotype of chondrocytes and respond well to PTH and glucocorticoids. It has been suggested that chondrocytes produce somatomedin-like growth factors which support their own growth and GAG synthesis. In the present study, we reported studies on the effect of conditioned medium obtained from cultures of rabbit craniofacial chondrocytes on GAG and DNA syntheses in the same chondrocyte cultures. Serum-free medium, conditioned by exposure to rabbit chondrocytes from mandibular condyle, nasal septum and sphenooccipital synchondrosis in monolayer culture stimulated not only the synthesis of GAG by the same cells but also their own DNA synthesis. The stimulation of the syntheses of GAG and DNA by the conditioned-medium factor were concentration-dependent. In addition, these three kinds of conditioned media stimulated GAG and DNA syntheses of other types of chondrocytes. These findings suggest that rabbit chondrocytes from the craniofacial complex release factors into the culture medium that enhance their own growth and expression of the differentiated phenotype of chondrocytes as well as that of costal chondrocytes.

Animals↗