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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 847 records · Page 47Linked to original sources
PubMed1994

Simultaneous determination of oxidized and reduced coenzyme Q and alpha-tocopherol in biological samples by high performance liquid chromatography with platinum catalyst reduction and electrochemical detection.

A convenient and sensitive high performance liquid chromatographic method with post-column platinum catalyst reduction and electrochemical detection was applied to the simultaneous determination of oxidized and reduced coenzyme Q (CoQ and CoQH2) and alpha-tocopherol (alpha-TP) in human and rat samples. After the separation of oxidized and reduced CoQ homologues (CoQ8-CoQ10 and CoQ8H2-CoQ10H2) and alpha-TP on a reversed-phase column, oxidized CoQ homologues were reduced on a platinum catalyst reduction column, and then all the reduced forms were quantified with an electrochemical detector operated in the oxidation mode (+ 0.6 V vs. Ag/AgCl). The order of elution was alpha-TP, CoQ8H2, CoQ9H2, CoQ8, CoQ10H2, CoQ9, and CoQ10 and all were well separated within 13 min. The detection limits at a signal-to-noise ratio of 3 were 20 pg for alpha-TP, 70 pg for CoQ8 and CoQ8H2, and 100 pg for CoQ9, CoQ9H2, CoQ10 and CoQ10H2. Quantitative recoveries (93-102%) from serum and tissues were obtained for all the analytes studied. This method was applied satisfactorily to the simultaneous determination of CoQ, CoQH2 and alpha-TP in biological materials.

Adult↗
PubMed1994

Distribution patterns of Gd-DTPA-enhanced magnetic resonance imaging after intravenous tissue plasminogen activator therapy for acute myocardial infarction.

In patients who received thrombolytic therapy for acute myocardial infarction (AMI), we observed 3 distinct patterns in gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA)-enhanced magnetic resonance (MR) imaging. To clarify the significance of these distribution patterns of Gd-DTPA, 20 consecutive patients underwent Gd-DTPA-enhanced MR imaging 7-10 days after AMI. All of the patients received intravenous recombinant tissue plasminogen activator (IVTPA) within 6 h of onset. Echocardiograms were obtained prior to and serially over 10 days, and interpreted for regional wall motion. Coronary angiograms were obtained the day before discharge. None of the 6 patients with a closed infarct-related artery, and 9 of the 14 patients with an open artery, demonstrated subendocardial enhancement (p < 0.05). All of these latter 9 patients demonstrated a significant improvement in wall motion between days 1 and 10 after AMI. In contrast, only 1 of the 7 patients with transmural enhancement and none of the 4 patients with non-homogeneous enhancement demonstrated improvement of wall motion on day 10 (p < 0.05). We concluded that subendocardial enhancement was a fair prognostic sign for restoration of regional cardiac function in patients who received IVTPA during AMI.

Aged↗
PubMed1994

Purification and characterization of xylanase A from Clostridium stercorarium F-9 and a recombinant Escherichia coli.

Xylanase A encoded by the Clostridium stercorarium F-9 xynA gene was purified to homogeneity from a recombinant clone of Escherichia coli. The N-terminal amino acid sequence and molecular weight (54,000) estimated by SDS-PAGE of the purified enzyme were consistent with those deduced from the nucleotide sequence [Biosci. Biotech. Biochem., 57, 273-277 (1993)]. A xylanase was also purified to homogeneity from a culture supernatant of C. stercorarium F-9. Its N-terminal amino acid sequence, molecular weight, and enzymatic properties were quite in agreement with those of the recombinant enzyme, indicating that the xynA gene was predominantly expressed as a xylanase gene in C. stercorarium F-9. The purified enzyme hydrolyzed xylotriose to yield xylobiose and xylose while it was less active toward xylobiose. It was optimally active at 75 degrees C and pH 7.0 Km and Vmax were estimated to be 1.9 mg/ml and 2.8 mumol of xylose equivalent/min/micrograms for oat spelt xylan, respectively.

Amino Acid Sequence↗
PubMed1994

Intraperitoneal administration of nucleoside-nucleotide mixture inhibits endotoxin-induced bacterial translocation in protein-deficient mice.

Nucleosides and nucleotides as a precursor for nucleic acid synthesis may be essential for rapidly growing cells, since intestinal epithelial cells have limited capacity for the de novo purine and pyrimidine synthesis. The present study was undertaken to determine the effect of intraperitoneal administration of nucleoside-nucleotide mixture (NNM) or saline on endotoxin-induced bacterial translocation, ileal histology, and cecal population levels in protein-deficient mice. Intraperitoneal administration of NNM for 14 days was associated with reduced translocation of gram-negative enterics to the mesenteric lymph node and spleen in comparison to saline. Histologically, the extent of the damage to the gut mucosa was greater in the saline group. This was confirmed by the profound diminution of the villous height, crypt depth, and the intestinal wall in the saline treated group as compared to the NNM treated group, suggestive of the efficacy of NNM in improving the gut and epithelial mucosal cells. However, the cecal population levels in both groups were not different. Additionally, the mice in the saline group were more susceptible to the lethal effects of endotoxin as compared to the NNM group suggesting that NNM may be essential for the enhancement of the host defense system. These results suggest that NNM may be used to an advantage to inhibit or reduce the incidence of endotoxin-induced bacterial translocation and improved survival in protein-deficient mice.

Animals↗
PubMed1994

Multiple myeloma complicated with streptococcal endocarditis successfully treated by mitral valve replacement.

A 63-year-old male patient with multiple myeloma developed congestive heart failure due to streptococcus endocarditis prior to the initiation of chemotherapy. Doppler echocardiographical examination revealed the presence of a large vegetation on the anterior mitral leaflet as well as the association of severe mitral regurgitation. Surgical repair (mitral valve replacement) was urgently undertaken and the postoperative course resulted in uneventful recovery. In immunodeficient patients with such a streptococcus sepsis, the possibility of infectious endocarditis should be taken into consideration and proper management is mandatory in these circumstances.

Endocarditis, Bacterial↗
PubMed1994

Polysplenia accompanied by major cardiovascular anomalies with prolonged survival.

A 52-year-old female with polysplenia accompanied by major cardiovascular anomalies (a ventricular septal defect, atrial septal defect, persistent left superior vena cava, absent inferior vena cava with a hemiazygos connection and visceral heterotaxia) is reported. She underwent successful surgical treatment and showed prolonged survival.

Abnormalities, Multiple↗
PubMed1994

Differentiation of histochemical properties of masticatory muscles in Bovidae and Cervidae (Artiodactyla).

We analyzed the masticatory muscles (masseter, temporal, medial pterygoid and lateral pterygoid muscles) of Bovidae and Cervidae (Artiodactyla) for the histochemical characteristics of their fiber types. Analysis of muscle fiber types in the present study was based on the staining reaction for SDH, Sudan black B, alpha-GPDH, and myosin-ATPase after alkaline preincubations. Histochemical properties were found to contribute to masticatory function, including a slow-twitch fatigue resistant activity derived from the high percentage of red fibers, in spite of the differences in the distributions of fiber types in three portions (superficial, medial and profound portions) of each masticatory muscle. These results indicate a correlation between the histochemical profiles of individual masticatory muscles in these species and their functions during jaw movements.

Animals↗
PubMed1994

The superior alveolar nerves: their topographical relationship and distribution to the maxillary sinus in human adults.

The superior alveolar nerves in human adults were investigated macroscopically using whole-mount silver impregnation, paying special attention to their topographical relationship and distribution to the mucous membrane of the maxillary sinus. In addition, the fiber composition of the alveolar nerves was analysed in order to estimate their contribution to teeth innervation. The posterior superior alveolar nerve (PSAN) ran through canaliculi in the lateral wall of the sinus (23 of 37 cases, 62.2%) or under the mucous membrane of the sinus (14 of 37 cases, 37.8%). Moreover, the PSAN gave off many fine twigs to make complex plexus under the mucous membrane of the sinus before joining the superior dental plexus. The plexus of the maxillary sinus was separated from the superior dental plexus by the bony wall of the sinus. After the above gross observations, the perimeter compositions of myelinated fibers of the plexus, PSAN and the anterior alveolar nerve were analysed in the same specimen. The plexus was composed of myelinated fibers of less than 27 microns in circumference perimeter (mean: 14.3 microns) and numerous unmyelinated fibers. The fiber composition suggested that few fibers in the plexus of the maxillary sinus contribute to the formation of the superior dental plexus. The superior dental plexus, innervating the upper teeth, was located in the thick alveolar process of the maxilla, and not on the maxillary sinus wall. The clinical importance of these results was discussed in relation to nerve injury during antrostomy of the maxillary sinus.

Aged↗
PubMed1994

Topographical anatomy of the internal mammary lymphatics in the superior mediastinum and anterior mediastinal lymph nodes.

The lymphatics lying along the internal thoracic artery and vein, which are termed the "internal mammary lymphatics" (IML), were minutely dissected in 134 adult cadavers (80 males and 54 females, aged 27-94 years) in order to clarify the configuration of IML in the superior mediastinum. On the right side, IML frequently terminated at the brachiocephalic angle (BA) nodes and often at the nodes situated at an intermediate position between the internal thoracic artery and vein. By way of these nodes, IML communicated with regional lymphatics of the lung and esophagus. Moreover, IML joined the right superficial bronchomediastinal trunks. On the left side, IML consistently terminated at a superficial group of aortic arch nodes, termed the "superior phrenic nodes", lying along the left phrenic nerve and lying medially to the internal thoracic vein and inferiorly to the left brachiocephalic vein. At and around these nodes, IML joined drainage routes from the so-called Botallo's nodes, which received the left lung lymphatics. The efferents of the superior phrenic nodes formed the left superior bronchomediastinal trunks, and passed deeply to the left brachiocephalic vein and on the subclavian artery toward the left venous angle region. Consequently, IML formed common drainage routes with the drainage routes from the lung and esophagus in the superior mediastinum. A transverse communicating route of IMLs via the retromanubrial nodes, lying inferior to or along the left brachiocephalic vein, was often observed. On the right side, the communicating route terminated at the BA nodes or the nodes situated at an intermediate position between the internal thoracic artery and vein. On the left side, the route consistently terminated at the superior phrenic nodes. In addition to the communicating route described above, we identified (1) a direct and superficial transverse communicating route, and (2) a deep transverse communicating route. The former route was composed of fasciculated large collecting vessels directly connecting the BA nodes to the left venous angle region, lying superficial to the left brachiocephalic vein. The latter route was composed of several large collecting vessels, crossing the brachiocephalic and left common carotid arteries superficially, and merging into the left phrenic nodes directly or occasionally via the pretracheal nodes. These results suggested that IMLs of both sides can closely communicate with each other in the superior mediastinum.

Adult↗
PubMed1994

Expression of intercellular adhesion molecule-1 and lymphocyte function-associated antigen-1 in the spinal cord of rats during acute experimental allergic encephalomyelitis.

We investigated the expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) by cells in the central nervous system (CNS) of Lewis rats during acute experimental allergic encephalomyelitis (EAE). A few endothelial cells in the CNS of normal rats expressed ICAM-1, whereas during the active phase of EAE, ICAM-1 was present on many endothelial cells. This alteration was detectable the day before clinical symptoms. Since histopathological studies showed few detectable mononuclear cells or inflammatory foci in any section of the preclinical rats, the expression of ICMA-1 was considered to be important at least in the early stage of inflammation. LFA-1 was seen on perivascular infiltrating cells. An increase in either ICAM-1- or LFA-1-positive cells was initially seen in the lumbosacral portion of the spinal cord, which then extended to the thoracic portion. The number of either ICAM-1- or LFA-1-positive cells peaked on the day of clinical onset in the lumbosacral portion. In contrast, in the thoracic portion, a peak in the number of either ICAM-1- or LFA-1-positive cells was observed on the day after clinical onset. This ascending extension of either ICAM-1- or LFA-1-positive cells was correlated with the progression of neurologic signs. It is suggested that increased expression of ICAM-1 and LFA-1 in the CNS of rat EAE may promote the extravasation of lymphocytes across the blood-brain barrier and be related to progression of the disease.

Acute Disease↗
PubMed1994

[Longitudinal change in independence in the elderly--Kahoku Longitudinal Aging Study (KLAS)].

A community based study named Kahoku Longitudinal Aging Study (KLAS) was conducted since 1990 for the purpose of evaluating the comprehensive geriatric functional assessment (CGA) and preventing a decline in CGA in the community-dwelling elderly population. It was carried out in a Japanese rural town, in which 32% of the population was over 65 years of age. This study included a questionnaire about activity of daily living (ADL), information-related physical function, mental (cognitive and affective) and social functional domains. In addition to subjective informative instruments, various types of objective assessment such as quantitative neuro-behavioral function tests and medical examinations were performed. Subjects were all the eligible elderly aged over 65 years in the community. Although the ratio of subjects who were independent in ADL decreased with advancing age in both 1991 and 1993, the ratio of the independent elderly in ADL became significant higher (74%) in 1993 than in 1991 (71%). Scores on 2 kinds of neurobehavioral function tests in the 159 subjects aged over 75 years who attended the examination every year showed a significant and slight decrease during two years. However, some test indices significantly improved during the 2 years. These results suggested that age-related dependency in ADL and some kind of neurobehavioral functions might be prevented, in part, by health promoting education and improvement of life style.

Activities of Daily Living↗
PubMed1994

[Characteristics of blood pressure regulating endocrinological factors in elderly essential hypertensives].

Plasma renin activity (PRA) was lower in elderly normotensive subjects and essential hypertensives (EHT), and a significant negative correlation was found between PRA and age in both groups. In EHT, the proportion of the low renin group to total EHT increased with aging. There was a significantly positive correlation between plasma norepinephrine (PNE) and age in NT, but not in EHT. The mean value of PNE in young subjects was significantly higher in EHT than in NT, but not in the middle-aged and elderly groups, suggesting the important role of PNE in young EHT. Power spectral analysis revealed a significant reduction of both sympathetic and parasympathetic activity with aging in NT and EHT, indicating much caution may be required if sympathetic nerve activity is evaluated only by PNE levels in elderly EHT. The expanded plasma volume was another characteristic in elderly EHT, and suppressed activity of renal kallikrein-kinin, prostaglandin and dopamine may be involved with its mechanisms. Regarding insulin sensitivity in elderly EHT, it was shown that 1) the reduction of insulin sensitivity plays some role in age related acceleration of hypertension and glucose intolerance, 2) selective insulin resistance with respect to glucose metabolism already exists at lower ages in EHT, and 3) both Na retention and pressor system activation via insulin action might be a cause of blood pressure elevation in EHT.

Adult↗
PubMed1994

[Fetal genitourinary abnormalities associated with oligohydramnios].

After 16 weeks of gestation, amniotic fluid mainly consisted of fetal urine. Therefore, the association of oligohydramnios with fetal urinary tract abnormalities implies severe deterioration of renal function. The relationship of the kidney and amniotic fluid in pulmonary development has been investigated, and fetuses with oligohydramnios starting in the second trimester are considered to have uniformly fatal outcomes. We analysed underlying urological disorders, gestational age at presentation, and ultimate outcomes in 45 fetuses with severe oligohydramnios, and especially focused on clinical courses and prognosis of 7 surviving patients. Clinical and/or autopsy diagnosis included bilateral renal hypodysplasia in 20 patients, urethral atresia with/without prune belly deformity in 9, posterior urethral valve in 6, polycystic kidney disease in 4, hydrometrocolpos in 2, hereditary renal dysplasia in 2, and the others. The average gestational age at detection of severe oligohydramnios was about 30 weeks, ranging from 16 weeks in patient with urethral atresia. Urological disorders of 7 surviving patients consisted of 4 posterior urethral valves, one hydrometrocolpos, one hydronephrosis of the solitary kidney, and one bilateral megaureter. In these 7 patients severe oligohydramnios striated in the third trimester. Four patients required ventilator supports together with the administration of surfactant, but they were weaned in one to 4 days. There was no evidence of pulmonary hypoplasia on chest X-ray films. Urological emergency drainage was necessary in all patients on the day of delivery to 2 days postnatally. One patient with posterior urethral valve developed ESRF 6 months after birth. Two patients have a normal serum creatinine, but another 4 have slight elevation of SCr for their age.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1994

Experimental study of lung transplantation from non-heart-beating donor following brain death in canine model of left lung allotransplantation.

Thirty mongrel dogs were divided into 3 groups. Group I was a normal control group (n = 4) without transplantation procedure. Group II was a transplantation control group (n = 5) with left lung allotransplantation from heart-beating donor. Group III consisted of animals (n = 8) which received lung allografts from non-heart-beating donor following brain death. In Group III, brain death was brought about by intracranial hypertension with the inflation of balloon in the subdural space of donor. After 6 hours, the mechanical ventilation was discontinued followed by cardiac arrest. Left lung was excised twenty minutes after the cardiac arrest and was washed out with cold Ep4 solution for subsequent orthotopic allotransplantation. Right pulmonary arterial occlusion test (RPAO) were carried out under right thoracotomy to evaluate graft function immediately and 7 to 14 days after the surgery. PaO2, PAP and CO were measured before and 20 minutes after RPAO. All animals in Group II and 7 of 8 animals in Group III survived more than 7 days after surgery. No significant differences in the value of PaO2, mean PAP and TPVR with RPAO among three groups at each time of assessment, showing the possibility of lung transplantation from non-heart-beating donor followed by brain death.

Anesthesia↗
PubMed1994

Pathophysiology and end-organ damage in elderly hypertensives.

PATHOPHYSIOLOGY OF HYPERTENSION: Blood pressure increases with advancing age in most developed countries. The pathophysiology of elderly hypertension is characterized by changes in the structure and function of the cardiovascular system. Changes in arterial structure lead to a decrease in aortic compliance, which augments the aortic pressure component generated by the wave reflection mechanism. The age-related increase in the reflected-wave component of arterial pressure may contribute, at least in part, to the age-related rise in systolic blood pressure. Disproportionately elevated systolic blood pressure in the elderly may account for the progressive increase in left ventricular mass with advancing age. In addition to the changes in vascular and cardiac structures, the haemodynamic function of elderly hypertensives is characterized by increased peripheral resistance as well as reduced cardiac output, renal blood flow and intravascular volume. In contrast to younger hypertensives, the sympathetic and renin-angiotensin systems may not be major factors in the genesis of high peripheral resistance in this patient group. END-ORGAN DAMAGE: The most important end-organ damage in elderly hypertensives is left ventricular hypertrophy with or without coronary heart disease, cerebrovascular disease or renal impairment. Furthermore, this end-organ damage is frequently asymptomatic (silent). The prevalence of silent cerebrovascular disease in particular is surprisingly high in this elderly population. Asymptomatic cerebrovascular disease has been shown to be associated with various cardiovascular risk factors, and depressed neurobehavioural function. Diurnal blood pressure variations appear to be related to end-organ damage. The presence of occult end-organ damage and co-existing diseases common in elderly hypertensives has important clinical implications in the management of this disorder.

Aged↗