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Biomedical subjects

M Yoshimura

Publications and source records attributed to M Yoshimura.

At least 469 records · Page 26Linked to original sources
PubMed1993

A huge non-invasive thymoma causing acute dyspnea.

We report a patient with an extra-ordinarily huge thymoma weighing 1,930 g and measuring 21 x 20 x 15 cm that filled almost the entire hemithorax. The tumor was successfully removed and the patient made a good recovery. Despite of its large size, the tumor was benign both clinically and histologically, and the pathological diagnosis was epithelial thymoma of non-invasive type. The perioperative changes of this patient's lung function are discussed in detail.

Acute Disease↗
PubMed1993

Results of surgical treatment for calcified tuberculous empyema: improved pulmonary function obtained with lung preserving policy.

We treated thirteen cases of calcified tuberculous empyema during the nine years from 1984 to 1992. Six patients having mild symptoms were categorized as Type I, and the remaining seven with severe symptoms as Type II. The patients of Type I were all successfully treated by complete empyemectomy with or without lung resection. All the patients of Type II suffered from major symptoms and were burdened by larger empyema cavities with formation of bronchial fistulas. Five of the latter were successfully treated, but two died, one from MRSA infection and another from intestinal necrosis following omentopexy. Our guide lines for the treatment of tuberculous empyema are: Lung resection must be minimal. Type I patients could be managed by simple empyemectomy with or without minor thoracoplasty. Open thoracostomy prior to the empyemectomy is not necessary. If the patient who belongs to Type II is aged and in a critical state, open thoracostomy must be taken as the first choice. Omentopexy is reliable, but it should be restricted to selected cases. Reasonable dead space and minor air leakage may safely be left behind if the cavity is surrounded by noninfected raw surface of the chest wall and diaphragm. Better quality of life was revealed by exercise test with improved oxygen consumption, compared to the preoperative state.

Aged↗
PubMed1993

Heterogeneity of the afterhyperpolarization of sympathetic preganglionic neurons.

The components of the afterhyperpolarization (AHP) of the sympathetic preganglionic neuron were studied in the slice of the upper thoracic spinal cord of the cat. In this neuron, the AHP consists of a fast (fAHP) followed by a slow (sAHP) component. While the fAHP had similar time course in all neurons studied (n = 116), the sAHP had considerable variability. Two components could be identified and the variability resulted from variation in the relative magnitude of these. Fifteen percent of neurons showed only an early component of the sAHP, 16% showed only a late component, and 69% showed both components. The early component of the sAHP was selectively blocked by apamin and d-tubocurarine, while the late component was selectively blocked by ryanodine, procaine or phenylephrine.

Action Potentials↗
PubMed1993

Role of insulin in the pathogenesis of hypertension associated with glucose intolerance.

The role of insulin in the pathogenesis of hypertension was explored in normal men and male patients with impaired glucose-tolerance. They were classified as normal (n = 94), borderline (n = 164), impaired tolerance (IGT, n = 104), or diabetes mellitus (n = 100) according to their response to an oral 75g glucose challenge. Besides routine laboratory examinations, fasting immunoreactive insulin and post-glucose insulin levels at 30 minutes were measured. Patients with impaired glucose tolerance were older and more obese than the normal subjects. Serum cholesterol and triglyceride concentrations increased with severity of the glucose tolerance impairment. However, renal function, as estimated by blood urea nitrogen levels did not differ among these four groups. Multiple regression analysis revealed that blood pressure correlates significantly with the obesity index, blood glucose, serum cholesterol and serum insulin in all four groups. Among these groups, the partial F ratios for the obesity index were the greatest in both normal and diabetic groups, but in both borderline and IGT groups those for insulin were the greatest. These results indicate that in patients with impaired glucose tolerance is hypertension associated more closely with hyperinsulinemia than it is in normal subjects or diabetic patients.

Adult↗
PubMed1993

[A case of primary systemic amyloidosis with skeletal muscle atrophy and congestive heart failure].

A 77-year-old male had been noticing progressive weakness of the legs for three years. By the age of 75 he had difficulty in climbing stairs. On admission, serum level of CPK was moderately high. There were weakness and atrophy of the proximal muscles. Deep tendon reflexes were depressed. Sensation was normal. The electromyogram and the biopsy of the femoral quadriceps muscles showed nonspecific changes. In 1989, he developed difficulty in walking and had congestive heart failure. On the second admission, moist rales were heard over the chest, and pitting edema was present in the lower extremities. The chest roentgenogram showed a cardiothoracic ratio of 63% and bilateral pleural effusion. The electrocardiogram showed atrial flutter with 2:1 conduction, QS in V1-3, rS in V4, and ST depression and T inversion in V5,6. The echocardiogram revealed a thick left ventricular wall and impaired left ventricular contraction (EF 22%). Macroglossia, hepatosplenomegaly and renal dysfunction were not noted. Congestive heart failure progressed and he suddenly died of ventricular tachycardia in December 1989. At autopsy, skeletal muscle fibers varied in size and showed fiber splitting. A cellular infiltration was observed in the stroma. Amyloid deposit was positively stained with Congo red. The heart weight was 570 g with marked left ventricular hypertrophy and moderate bilateral atrial dilatation. In both atria and ventricles, extensive amyloid deposition was found around myocardial fibers as well as in perivascular spaces. Amyloid was present also in the liver, the kidneys, the gastrointestinal tracts, and the other organs.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Validity of clinical diagnosis in age-associated dementia].

With neuropathological diagnosis as the point of reference, the validity of clinical diagnosis was studied in 50 patients who had met DSM-III-R criteria for dementia. Clinical diagnosis of ATD (dementia of Alzheimer type) was made in 14 cases, of VD (vascular dementia) in 14 cases, of others in 5 cases and of undefined in 16 cases. At necropsy, 16 cases fulfilled the histological criteria for ATD, while 15 cases were VD, 3 cases were mixed dementia and 14 cases were other CNS disorders. In 2 other cases, the neuropathological picture was considered to be nondiagnostic. The accuracy of clinical diagnosis of VD was higher than that of ATD. Clinical diagnostic sensitivity was 81.8% for ATD and 91.7% for VD; corresponding specificity was 78.3% and 86.4%. With our clinical criteria, slowly evolving VD with no clinical evidence of stroke would not be identified as VD. On the other hand, AD patients who happened to have a stroke would be diagnosed as VD. These results suggest that further investigations as to VD (its clinical course, findings of computed tomographic scan and magnetic resonance imaging) are needed for more appropriate clinical criteria.

Aged↗
PubMed1993

[Shortening of life expectancy in patients with membranous nephropathy--based on 20 years follow up study].

It is not certain whether the life expectancy of patients with membranous nephropathy is shorter than that of an age-matched healthy population. Forty-one patients (21 males, 20 females) aged between 16 and 70 years (average age: 33.3 years) were followed for 20 years. The patients were divided into two groups: group I (n = 18), consisting of patients in whom nephrotic syndrome persisted for more than two years or until death, and group II (n = 23), consisting of patients except for group I. The non-survival criteria are death or renal death. Twelve patients (29.3%) died during the study period. Eight patients belonged to group I and 4 to group II. The causes of death in group I patients were end-stage renal failure in 3 cases, ischemic heart disease in 1 case, subarachnoid hemorrhage in 1 case, malignancy in 2 cases, suicide in 1 case, and those in the group II patients were pneumonia, malignancy, cerebral softening, and diabetes mellitus, respectively. Eight patients who died in group I had a significantly longer difference between their actual life span (ALS) and life expectancy (LE) and a significantly smaller ratio of ALS to LE than the patients who died in group II (ALS-LE: -29.9 +/- 4.5 years in group I vs. -9.0 +/- 6.8 years in group II, p < 0.05, ALS x 100/LE: 22.5 +/- 8.0% in group I vs. 80.9 +/- 25.2% in group II, p < 0.05). In group I, the ratio of observed to expected death was 4.76 (95% confidence interval, 2.05 to 9.37) and significantly higher than that of the control population. In group II, however, the ratio was 1.09 (95% confidence interval, 0.30 to 2.80), and the difference from the control population was not statistically significant. These results suggest that longstanding nephrotic syndrome is associated with a shortened life expectancy in patients with membranous nephropathy.

Adolescent↗
PubMed1993

[Recent progress in Holter electrocardiography, focussed on heart rate variability].

Heart rate variability has attracted attention as an index of the effects of the autonomic nerve system on the heart rhythm. Heart rate variability (HRV) is low in patients at risk for sudden death. We evaluated the effects of caffeine, whole-day work without sleep and drugs on HRV. Caffeine had no effects on HRV or ventricular extrasystoles in young adults but aggravated those in obese middle-aged subjects. Whole-day work without sleep increased blood catecholamines and decreased HRV. These findings also suggest the usefulness of HRV as an index in health management. Tofisopam, enalapril and aprindine significantly improved HRV. These drug may be useful for maintaining normal autonomic nerve activity and preventing autonomic nerve diseases or sudden cardiac death in this stressful society.

Adult↗
PubMed1993

Studies on secular changes in the concentration of lead accumulated in organs and rib of Japanese.

As environmental pollution due to waste fluids and gases from factories using lead (Pb), as well as domestic waste materials, has become a matter for public concern, studies on the accumulated levels of Pb in man have become necessary for defining the degree of contamination in the ordinary population. For this purpose, Pb levels in tissues of 76 forensic cadavers were determined in order to investigate the age distribution of accumulated Pb, and 120 samples were used to clarify secular changes in Pb accumulation during the last decade in the general population. The age group showing the highest Pb level was 50-59 years, with mean Pb contents per unit wet weight of 0.262, 0.520, 0.427 and 4.479 micrograms/g for heart, liver, kidney and rib, respectively. Each of these organs in all age groups exhibited almost the same Pb levels, but babies less than one year old had levels close to those in adults. However, ribs in babies exhibited much lower Pb levels. The levels in each organ were lower in individuals over 60 years old. A distinct age-related increase in Pb levels was found only in ribs from age 0 year to 50-59 years. The Pb levels in the heart, liver, kidney and rib showed a decrease during the last 10 years from 0.188 +/- 0.073 to 0.006 +/- 0.003 micrograms/g, from 0.307 +/- 0.169 to 0.076 +/- 0.057 micrograms/g, from 0.287 +/- 0.145 to 0.021 +/- 0.011 micrograms/g and from 3.203 +/- 1.477 to 2.366 +/- 1.469 micrograms/g, respectively.

Adolescent↗
PubMed1993

[Study on secular changes of cadmium concentration accumulated in main organs of Japanese].

With the development of the mining and manufacturing industries and the petrochemical industry, cadmium (Cd) has been used not only for metal products but also petroleum products. Recently, environmental pollution due to waste fluids and gases from factories using cadmium and also domestic waste materials has become a cause for concern. In this connection, studies on the accumulated levels of Cd in the human body, its age-distribution in the general population and its secular changes during the last decade would be useful for clarifying the degree of contamination in the human body and providing an index which could be used as a basis for preventive measures against environmental pollution. For this purpose, the levels of Cd accumulated in main organs of the human body were determined using forensic data 3 times at 5-year intervals starting in 1976. The age intervals starting in 1976. The age group having the highest Cd level was 50-59 years, old and the mean weights of Cd per wet weight of heart, liver and kidney were 0.421, 2,984 and 56.43 micrograms/g, respectively. Each of these organs in babies less than a year old exhibited lower Cd levels, but teenagers had levels close to those in adult. However, the level in each organ was lower in individuals over 60 years old. 4 distinct age-related increase in the level of Cd was found only in the kidney. The levels of accumulated Cd in the liver and kidney showed a rise during the last 10 years from 2.358 to 5.568 micrograms/g and from 43.95 to 73.47 micrograms/g, respectively, whereas the Cd level in the heart has remained about the same, i.e. from 0.207 to 0.181 micrograms/g.

Adolescent↗
PubMed1993

[An autopsy case with recent memory disturbance, characterized by localized atrophy of parahippocampal gyrus, subiculum and amygdala].

We reported an autopsy case with recent memory disturbance, characterized by localized atrophy of parahippocampal gyrus, subiculum and amygdala. This patient initially exhibited recent memory disturbance at the age of 73. She was disoriented to time and place and immediately forgot having had a meal. At the age of 75, she was hospitalized because of progressive forgetfulness and congestive heart failure. One year later, she was admitted to our medical center. On admission, she was alert, but showed severe recent memory disturbance and disorientation to time and place. By contrast, she had neither aphasia nor apraxia. No other neurological symptoms were found. Brain CT showed localized atrophy of the medial part of bilateral temporal lobes and brain SPECT (123I-IMP) revealed a decrease of cerebral blood flow in the same regions. We considered her as early stage of Alzheimer type dementia (ATD) clinically. She died of pneumonia and DIC at the age of 78. Her illness lasted about 5 years. General autopsy showed prolapse of mitral valves, bronchopneumonia and DIC. The brain weighed 1,150 gm. Coronal sections of the brain revealed locarized atrophy of bilateral mediobasal part of the temporal lobes including the rostral parahippocampal gyrus, subiculum and amygdala. There were severe neuronal loss with astrogliosis and a few neurofibrillary tangles (NFT) in the rostral para-hippocampus, CA1 of the hippocampal formation, prosubiculum and amygdala. There were neither senile plaques (SP) nor NFT in the cerebral neocortex. This case lacked neocortical SP and NFT and showed bilateral localized atrophy of rostral parahippocampal gyrus, CA1, subiculum and related structure of the ventromedial temporal lobe with severe neuronal loss and astrogliosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Studies on the gamma delta T lymphocytes in the peripheral blood in healthy adults].

Since gamma delta T lymphocytes has been found to be increased in patients with some immunological disorders, there exists clinical needs to determine the population of the cells in peripheral blood in normal subjects. We counted the number of gamma delta T lymphocytes in samples obtained from 151 healthy volunteers, aged from 20 to 69 years, by using a dual-color flow cytometry with fluorescence-conjugated CD3 and anti-TCR-gamma delta antibodies. Distribution ratio of gamma delta T lymphocytes among peripheral blood lymphocytes was 3.8 +/- 2.5% (range, 0.6-16.1%). Difference in the ratio and the number of gamma delta T lymphocytes among sex was not significant, but those decreased slightly but significantly with age.

Adult↗
PubMed1993

Clinical and neuropathological aspects of diffuse Lewy body disease in the elderly.

This chapter reports the clinical and neuropathological findings of eight cases of "diffuse Lewy body disease" verified by autopsy. The age at onset was between 60 and 82 years; the age at death was between 75 and 92 years. The initial symptoms were amnesia in three cases, orthostatic dizziness in three, visual hallucination in two, but parkinsonism in none. The cardinal clinical symptoms included dementia in all cases, hallucinatory-delusional state in six, akinesia and rigidity in five, and orthostatic hypotension in five. Antemortem diagnoses were senile dementia in five, and hallucinatory-delusional state, Parkinson's disease and Shy-Drager syndrome in one each. Despite the clinical symptoms differences from each other, neuropathological findings were alike. Abundant Lewy bodies were present in the neurons of the cerebral cortex as well as in the brainstem nuclei and diencephalon. Concomitant senile changes including senile plaques and Alzheimer's neurofibrillary tangles (NFTs) were also present in varying degree. Immunocytochemical study with anti-ubiquitin for Lewy body, anti-tau protein for NFT, and beta-protein of amyloid for senile plaque suggested that dementia of DLBD might have resulted not from a single pathology but from the complex of Lewy bodies, NFTs and senile plaques.

Aged↗
PubMed1992

Excitatory amino acid receptors involved in primary afferent-evoked polysynaptic EPSPs of substantia gelatinosa neurons in the adult rat spinal cord slice.

Intracellular recordings were made from substantia gelatinosa (SG) neurons in spinal cord slices to determine a subclass of excitatory amino acid receptors involved in polysynaptic excitatory postsynaptic potentials (EPSPs). In the majority of neurons, polysynaptic EPSPs evoked by A delta fiber were not affected by 2-amino-5-phosphonovaleric acid (APV), while all EPSPs including monosynaptic EPSPs were depressed by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). All spontaneous EPSPs were blocked by CNQX, while spontaneous EPSPs in a few SG neurons were attenuated by APV. These observations suggest that polysynaptic EPSPs evoked through A delta fibers are predominantly mediated by activation of the non-N-methyl-D-aspartate (non-NMDA) receptor subclass.

2-Amino-5-phosphonovalerate↗
PubMed1992

Cloning and expression of a Ca(2+)-inhibitable adenylyl cyclase from NCB-20 cells.

A cDNA that encodes an adenylyl cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] has been cloned from NCB-20 cells, in which adenylyl cyclase activity is inhibited by Ca2+ at physiological concentrations. The cDNA clone (5.8 kilobases) was isolated by polymerase chain reaction (PCR) using degenerate primers designed by comparison of three adenylyl cyclase sequences (types I, II, and III) and subsequent library screening. Northern analysis revealed expression of mRNA (6.1 kilobases) corresponding to this cDNA in cardiac tissue, which is a prominent source of Ca(2+)-inhibitable adenylyl cyclase. The clone encodes a protein of 1165 amino acids, whose hydrophilicity profile was very similar to those of other mammalian adenylyl cyclases that have recently been cloned. A noticeable difference between this protein and other adenylyl cyclases was a lengthy aminoterminal region before the first transmembrane span. Transient expression of this cDNA in the human embryonic kidney cell line 293 revealed a 3-fold increase in cAMP production in response to forskolin compared with control transfected cells. In purified plasma membranes from transfected cells, increased adenylyl cyclase activity was also detected, which was susceptible to inhibition by submicromolar Ca2+. Thus, this adenylyl cyclase seems to represent the Ca(2+)-inhibitable form that is encountered in NCB-20 cells, cardiac tissue, and elsewhere. Its identification should permit a determination of the structural features that determine the mode of regulation of adenylyl cyclase by Ca2+.

Adenylyl Cyclase Inhibitors↗
PubMed1992

Histological study on ouabain immunoreactivities in the mammalian hypothalamus.

The endogenous digitalis-like factor (EDLF) which has recently been purified from human plasma and identified as 'ouabain', a cis-trans-cis steroid of plant origin, is thought to be similar to the hypothetical humoral factor, 'endogenous digitalis-like substance (EDLS)'. In order to examine the hypothesis that EDLS is produced in the hypothalamus, we prepared an ouabain-specific antibody, and applied it to rat and macaque brains. Ouabain immunoreactivities were observed in the hypothalamus of both species. The immunopositive neurons were distributed in paraventricular and supraoptic nuclei, and some other hypothalamic regions. Their nerve fibers were seen abundantly in the hypothalamo-neurohypophysial regions. These results strongly support the possibility of existence of cis-trans-cis steroid including EDLF in mammalian brain.

Animals↗
PubMed1992

Distribution of the endogenous digitalis-like substance (EDLS)-containing neurons labeled by digoxin antibody in hypothalamus and three circumventricular organs of dog and macaque.

Endogenous digitalis-like substance (EDLS) is a newly discovered humoral agent which causes sodium-diuresis. EDLS is well known to have inhibitory activity to Na+,K(+)-ATPase and cross-immunoreactivity to digoxin antibody; however, its precise chemical structure has not yet been determined. We had previously developed a histochemical technique for EDLS, i.e., digoxin-immunohistochemistry, and demonstrated that EDLS was produced in the hypothalamic neurons. In the present study, the distribution of EDLS-containing neurons in the hypothalamus of dog and macaque was investigated using this technique, because anti-EDLS antibody cannot be obtained yet. In both species, EDLS neuronal somata were mainly localized in the paraventricular nucleus and the supraoptic nucleus and its accessory nuclei. A number of somata were also scattered in the other hypothalamic areas. The processes of these neurons ran from the area where the somata were located, through the lateral and basal area of the hypothalamus, to the infundibulum. These nerve fibers with varicosities were associated with the primary capillaries of hypophysial portal veins. A few immunopositive nerve fibers were also seen in the pituitary posterior lobe of both species. Intensive immunoreactivities were observed in the subfornical organ and organum vasculosum laminae terminalis. There were no differences between dog and macaque.

Animals↗