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Biomedical subjects

M Shoji

Publications and source records attributed to M Shoji.

At least 271 records · Page 15Linked to original sources
PubMed1990

Effects of intracerebroventricular administration of adrenoceptor-agonists on the regulation of renal water and electrolytes handling through endocrine, renal and hemodynamic function.

In order to assess the roles of central adrenoceptors in the release of atrial natriuretic peptide (ANP), aldosterone (ALD), vasopressin (AVP) and renin as well as in the regulation of renal and cardiovascular functions, either norepinephrine (NE; 0.07 microgram/kg/min), guanabenz (GB; alpha 2-agonist; 0.4 microgram/kg/min), methoxamine (MET; alpha 1-agonist; 0.4 microgram/kg/min), or isoproterenol (ISO; beta-agonist; 0.07 microgram/kg/min), dissolved in the artificial cerebrospinal fluid (ACSF), was intracerebroventricularly (i.c.v.) administered at a rate of 10 microliters/min for 30 min in anesthetized dogs. In the control study, the drugs were omitted. NE decreased mean arterial pressure (MAP), urinary osmolality (Uosm) and plasma ALD and AVP concentrations, and increased urine flow (UF). GB increased UF and urinary K excretion without any changes in urinary Na excretion, but decreased plasma ALD and AVP, heart rate, and Uosm without changes in MAP. ISO decreased MAP and plasma ALD, and increased Na and K output, renal plasma flow and UF with decreased Uosm. MET and ACSF failed to affect any of these parameters. Glomerular filtration rate, plasma ANP concentration and renin activity did not change in any of the studies. The present results suggest that central alpha 2- and beta-adrenoceptors may attenuate ALD and/or AVP release without changes in ANP and renin release, and decrease blood pressure, thereby causing a diuresis and natriuresis.

Adrenergic alpha-Agonists↗
PubMed1990

Alzheimer amyloid beta-protein precursor in sperm development.

We prepared antisera to both the N and C termini of amyloid beta-protein precursor (APP). Both antisera labeled 110 to 140 kd proteins from rat testis by immunoblotting. Northern blot analysis using oligonucleotide probes complementary to respective APPs showed that APPs expressed in rat testis contained Kunitz-type protease inhibitor domains. Immunocytochemically brain APP was localized in neurons and their processes. During sperm formation, APPs labeled by both antisera were localized only in acrosome and the growing tail of spermatids in the seminiferous tubules. This shows that APPs appear only in particular phases of spermatogenesis, that is, in the morphologic change phase from spermatid to mature sperm. Amyloid beta-protein precursors in testis may play a role in cellular differentiation or morphologic change.

Amyloid beta-Peptides↗
PubMed1990

[Studies on respiratory infections in primary care clinic (II). Distribution and antibiotic sensitivity to 45 agents of bacteria isolated from patients with respiratory infections visiting a doctor in private practice].

The bacteriology of the isolates from the sputum or the throat swab of patients with respiratory infections visiting a doctor in private practice in Sendai city during the period from March in 1988 to February in 1989 was documented, and their sensitivity to 45 antimicrobial agents was determined. Of the 568 patients, 514 cases had acute pharyngitis, 8 cases each had acute tonsillitis and acute bronchitis, 7 cases were acute pneumonia, 6 cases had herpangina, 18 cases had hand-foot-mouth disease with the signs of respiratory infections, 5 cases had varicella with the signs of respiratory infections and 2 cases were mumps with the signs of respiratory infections. Three hundred strains of potential (greater than or equal to 10(7) CFU/ml) pathogens were recovered from 293 of the 568 cases, which consisted of 124 strains of Haemophilus influenzae, 58 strains of Streptococcus pneumoniae, 45 strains of Staphylococcus aureus, 26 strains of Branhamella catarrhalis, 25 strains of Streptococcus pyogenes, 9 strains of Klebsiella pneumoniae and 13 strains of other species, not including non-fermentile gram-negative bacteria such as Pseudomonas aeruginosa and Acinetobacter calcoaceticus. Staphylococcus aureus and other strains were documented simultaneously in 6 out of 7 cases in which multi-organisms were recovered. Many strains of Staphylococcus aureus were isolated from young patients throughout the year. On the other hand many strains of Branhamella catarrhalis were isolated from elderly patients in winter. The sensitivity of 45 antimicrobial agents of 231 of 300 strains was determined by sensitivity disks (EIKEN, Japan). No strain of the Haemophilus influenzae in this study was resistant to ampicillin. None of the Streptococcus pneumoniae and Streptococcus pyogenes was resistant to ampicillin or cefazolin. None of the Staphylococcus aureus was resistant to cloxacillin, cefazolin, gentamicin or ofloxacin. We conclude from the above results that antibiotic-resistant strains are found presumably only in a very few cases in primary care clinic.

Anti-Bacterial Agents↗
PubMed1989

Characteristic effects of taste-compounds on the dynamic behavior of oleate-monolayer.

Dynamic behavior of the monolayer of oleic acid on an aqueous solution was studied. The hysteresis loop of the surface, pressure (pi)-area (A) curve, was found to be characteristically dependent on the chemical stimuli with different taste-categories: salty, sweet, bitter and sour. The characteristic response of the dynamic surface behavior was discussed in relation with our recent finding, i.e., the features of the oscillation change in a different manner with the addition of various chemical species belonging to different taste categories in an excitable artificial liquid-membrane of oleic acid (Yoshikawa, et al, Langmuir, 4, 759-762 (1988).

Acids↗
PubMed1989

Fluorimetric studies of protein kinase C interactions with phospholipids.

Dansyl-phosphatidylserine (D-PS) was used as a fluorescence probe to study interactions between protein kinase C (PKC) with phospholipid vesicles. It was found that D-PS fluorescence (520 nm) was enhanced by PKC (excited at 285 nm). The fluorescence energy transfer, indicative of a close association of PKC with D-PS vesicles, was differentially modulated by various phospholipids, depending upon their effects on PKC activation state and the manners in which they were present. PKC inhibitors (e.g. polymyxin B and ether lipids) potently inhibited the PKC-enhanced D-PS fluorescence. It is suggested that certain spatial arrangements between PKC and its phospholipid cofactor are essential for the enzyme activation and that D-PS would be a useful probe to study fluorimetrically such interactions.

Animals↗
PubMed1989

Diffuse type of senile plaques in the cerebellum of Alzheimer-type dementia demonstrated by beta protein immunostain.

We studied senile plaques (SP) in the cerebella of six autopsied subjects with Alzheimer-type dementia (ATD) and ten non-ATD autopsied subjects between the ages of 78 and 90. Neither SP nor amyloid angiopathy (AA) was observed in any of the non-ATD subjects. In the four of the six ATD subjects, diffuse plaques in the molecular layer were seen as ill-defined areas of fine fibrillar materials by beta protein immunostaining with formic acid pretreatment, the modified Bielschowsky stain, and periodic acid-methenamine silver (PAM) stain. The plaques were not visible with Bodian, Congo red, or periodic acid-Schiff stains. Compact plaques in the Purkinje cell or in the granular cell layers were found in three of the six subjects. Their amyloid core was often surrounded by areolar amyloid deposits. AA was observed in three of the six subjects. The argyrophilia of the diffuse and compact plaques, demonstrated by the modified Bielschowsky and PAM stains, became undetectable when the sections were first treated with formic acid. Such treatment made the plaques immunoreactive with beta protein antiserum. The findings suggested that cerebellar diffuse plaques and compact plaques consist mainly of an amyloid component, and are characteristic of ATD.

Aged↗
PubMed1989

Characteristic response to taste stimuli of the intensities of higher harmonics in an electrochemical oscillatory system.

In general, the electrochemical characteristics of solid/liquid or liquid/liquid interfaces are highly nonlinear, i.e., the capacitance changes markedly according to the applied voltage. In this paper, we propose a novel method for evaluating these nonlinear characteristics quantitatively. That is, a sinusoidal voltage source is applied to a test solution and the waveform of the output current is analyzed by Fourier transformation. It is shown theoretically that higher harmonic components in the Fourier transformation afford us useful information on nonlinear behavior. It is stressed that our technique is entirely different from the classical impedance method, i.e., nonlinear components of the impedance can be evaluated in our method, having been ignored previously in the classical impedance measurement. As an application of this method, we have studied the effect of taste compounds on the intensities of the higher harmonics, using an electrochemical cell containing an aqueous solution of sodium oleate. It has been found that the intensities of the higher harmonics exhibit characteristic changes upon the addition of taste compounds, the change being dependent upon the taste category. The characteristic response to taste compounds in the electrochemical nonlinearity is discussed in relation to the experimental trend of the dynamic isotherm for oleic acid at an air/water interface.

Animals↗
PubMed1989

[Studies on respiratory infections in the field of primary care (I). Correlation between viral infection and secondary bacterial infection in patients visiting a doctor in private practice].

We attempted to find out whether there is a correlation between viral infection and secondary bacterial infection on the basis of the analysis of the results of the culture of virus and bacteria in the same specimen from the throat swabs of 95 patients who had an acute upper respiratory inflammation when they visited a doctor in private practice in Sendai city during the epidemic caused by influenza virus. Viral culture was performed by a microplate-method devised originally by Numazaki. The influenza virus was recovered from 56 cases (59%) consisting of 43 cases of type A (Hong-Kong) and 13 cases of type B. From 73 cases, (77%), 79 strains of possibly pathogenic bacteria were recovered, consisting of 43 strains of H. influenzae, 18 strains of S. aureus, seven strains of S. pneumoniae, four strains each of C. freundii and S. liquefaciens and one strain each of beta-haemolytic Streptococcus and B. catarrhalis. The incidence of positive culture of both virus and possibly pathogenic bacteria was high already at the early stage (2-3 days) of the disease. We found no correlation between the type of virus and the species of the microbial isolates. There was no difference in the incidence of positive bacterial culture in relation to age group. We suggest that a secondary bacterial infection occurs already at the early stage of the disease after viral infection because the incidence of positive culture of possibly pathogenic bacteria was high at the above stage.

Adolescent↗
PubMed1989

Attenuation of the osmotic release of vasopressin by enkephalins in dogs.

To assess the possible role of circulating enkephalins in the osmotic release of vasopressin, Met5 (M-Enk)- or Leu5-enkephalin (L-Enk) dissolved in 0.9 or 10% NaCl was infused to either anesthetized or conscious dogs at a dose of 3.5 nM.kg-1.min-1 for 15 min. Intravenous infusion of M-Enk or L-Enk produced 150- to 200-fold increases in their plasma levels, and the elevated levels were maintained during the infusion. Although blood pressure (BP) in anesthetized dogs decreased significantly during L-Enk infusion, BP in conscious dogs was unaffected by both enkephalins. Neither M-Enk nor L-Enk infusion affected plasma vasopressin concentration (PAVP) in these anesthetized and conscious dogs that were not osmotically stimulated. PAVP in conscious time control dogs increased significantly after start of 10% NaCl infusion in spite of an increase in BP. M-Enk or L-Enk significantly blunted the increase in PAVP induced by 10% NaCl infusion. This attenuation was not accompanied by any significant changes in plasma sodium concentration and BP compared with those of time control dogs. Thus increase in plasma enkephalins attenuates the osmotic release of vasopressin.

Animals↗
PubMed1989

Responses of vasopressin, atrial natriuretic peptide, and blood pressure to central osmotic stimulation.

To assess whether intracerebroventricular osmoreceptors are involved in vasopressin (AVP) and atrial natriuretic peptide (ANP) release and in the pressor response to centrally administered hypertonic NaCl, artificial cerebrospinal fluid (ACSF) or ACSF made hypertonic by adding 0.2 M NaCl, 0.4 M mannitol, and 0.4 M glucose in isotonic ACSF or 0.4 M urea was infused into the 3rd ventricle of conscious rats. In addition, intravenous infusion of [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid),2-(O-methyl)tyrosine]AVP (TMeAVP), a V1-AVP antagonist, was given in rats receiving intracerebroventricular infusion of 0.2 M NaCl in isotonic ACSF. Intracerebroventricular 0.2 M NaCl, 0.4 M mannitol, and 0.4 M glucose in isotonic ACSF increased plasma AVP and mean arterial pressure (MAP) without changing heart rate (HR) or plasma ANP. Urea at 0.4 M decreased plasma AVP and ANP with a slight rise in MAP but no change in HR. ACSF alone did not affect plasma AVP, ANP, MAP, or HR. Intravenous TMeAVP attenuated the pressor response to infusion of 0.2 M NaCl in isotonic ACSF, decreased plasma ANP, but did not affect HR. These results indicate that central osmoreceptors are involved in the release of AVP and in the pressor response to centrally administered hypertonic NaCl.

Animals↗
PubMed1989

Effect on vasopressin release of microinjection of angiotensin II into the paraventricular nucleus of conscious rats.

We have studied in conscious unrestrained rats the role of angiotensin II receptors in the paraventricular nucleus (PVN) in the control of vasopressin secretion under basal conditions and after 24 h of water deprivation. In euhydrated rats, the microinjection rostral to the PVN of 1 and 5 ng of angiotensin II produced a transient, dose-dependent increase in the plasma vasopressin concentration. There was also a transient, but not dose-dependent, rise in mean arterial blood pressure (MABP), without a change in heart rate. However, the microinjection of angiotensin II into the PVN and sites caudal to it was without effect on the measured variables. In dehydrated rats, on the other hand, microinjection of 5 ng angiotensin II, both into the PVN and rostral to it, resulted in a prolonged increase in the plasma vasopressin concentration. The response from the rostral site was more rapid and was associated with an increased MABP. These findings suggest that angiotensin II receptors rostral to the PVN may participate in the control of vasopressin release in both euhydrated and dehydrated states, whereas angiotensin II receptors in the PVN are effective only following dehydration.

Angiotensin II↗
PubMed1989

[Pharmacological effects of reiousan on experimental hepatic injuries and hepatic functions].

Pharmacological effects of Reiousan, a crude drug preparation consisting of bezoar and ginseng, on experimental hepatic injuries and hepatic functions were studied. After administration of Reiousan, carbon tetrachloride, d-galactosamine and alpha-naphthylisothiocyanate-induced experimental hepatic injuries in rats were inhibited. Facilitation of recovery from increased retention rate of sulfobromophthalein in hepatectomized rats, increase in hepatic blood flow, inhibition of superoxide anions, and decrease in blood ethanol concentration in rats administered ethanol were observed after application of Reiousan. Inhibitory effects of Reiousan on experimental hepatic injuries may result from the increase in hepatic blood flow and inhibition of superoxide anions.

1-Naphthylisothiocyanate↗
PubMed1989

Surgical correction and osteoplasty for forward dislocation of temporomandibular joint.

Surgical correction and osteoplasty were carried out in one case of prolonged and three cases of recurrent forward dislocation of the temporomandibular joint, two of the patients in the latter cases having mental disorders and one having a cerebral lesion. A hockey-stick-shaped preauricular incision was made, ending in the hair-bearing part of the temple. Then, the temporal fascia and muscle were divided anteriorly from the temporal bone. In two aged patients, a fragment of the zygomatic arch was pushed out and down, joining under the articular tubercle. In two younger patients, the cortical bone of the mandible was separated by sagittal split-ramus osteotomy for mandibular prognathism, and two graft blocks removed from the iliac bone were implanted between the root of the posterior zygomatic arch and the anterior cut-edge of the articular tubercle. In 3 of the 4 patients, the fragments or grafts were fixed by means of ligation using wire so as to make contact with the root of the posterior zygomatic arch. There was no recurrence of dislocation during a period of 2-5 years after surgery.

Adult↗
PubMed1989

Alzheimer type dementia: diffuse type of senile plaques demonstrated by beta protein immunostaining.

We classified senile plaques (SP) into 4 types: diffuse, primitive, classic, and compact. Here, we studied the nature of diffuse plaques in the brains of 6 autopsied subjects with senile dementia of the Alzheimer type (SDAT). In the entorhinal cortex, both the modified Bielschowsky stain (108%) and periodic acid-methenamine silver (PAM) stain (111%) revealed a number of SP similar to that labeled by beta protein immunostain (100% as standard). The Bodian stain, however, labeled only a minor proportion (37%) of SP. The vast majority of Bodian-negative plaques, which were devoid of swollen neurites, were diffuse plaques. They were seen as ill-defined areas of fine fibrillar materials. Diffuse plaques were argyrophilic when labeled by the modified Bielschowsky and PAM stains. However, they became undetectable when sections were pretreated with formic acid. Formic acid pretreatment made the diffuse plaques immunoreactive with beta protein antiserum. Alzheimer's neurofibrillary tangles (ANT) and the neuritic components of the primitive and classic plaques remained argyrophilic even after pretreatment with formic acid. Our findings suggest that formic acid pretreatment selectively abolishes the argyrophilia of the amyloid-related component of SP, and the diffuse plaques consist mainly of amyloid-related, while the neuritic component does not. Positive reaction products for beta protein were scattered in the SP by immunoelectron microscopy. Some of the reaction products labeled 10 nm filaments resembling amyloid fibrils.

Aged↗
PubMed1989

A study of beta protein precursor using antiserum against a synthetic peptide (1-28).

We studied the presence of the beta protein precursor by immunocytochemistry and Western blot analysis using antiserum against a synthetic beta peptide (1-28). The brains of 4 patients with dementia of the Alzheimer type (DAT) were examined immunocytochemically. Frozen and formic acid pretreated paraffin sections were best for beta protein immunostaining. Both the senile plaque amyloid and cerebrovascular amyloid were immunostained with 28K1. In addition to primitive and typical plaques, amorphous granular or fibrous deposits of amyloid were observed in high numbers in various areas of the DAT brains. However, the beta protein precursor, which was suggested to be present in neuronal cells by in situ hybridization, was not stained. Neurofibrillary tangles were not stained, either. Sera and cerebrospinal fluid (CSF) from 6 patients with DAT were examined using Western blot analysis. A 52-kD band was detected with 28K1 in DAT patients as well as in normal controls. Further investigation revealed the 52-kD band to be the heavy chain of IgG. The staining pattern using the beta protein immunostain was quite different from the IgG immunostain. In this study there was no detection of the beta protein precursor, with the use of immunocytochemistry and Western blot analysis. Thus, further investigations are necessary using the antiserum against other residues of the beta protein precursor or using specimens without IgG.

Alzheimer Disease↗
PubMed1989

Effect of naloxone on hormonal changes during exercise.

It is well established that prolactin release during exercise is one of the important factors in exercise-induced menstrual dysfunction. The purpose of this study is to clarify the mechanisms of prolactin release during exercise. Ten female athletes measured their BBT every morning. They performed incremental exercise on a cycle ergometer, with or without naloxone, on the 5th to 8th days of the follicular phase. Three minutes before the exercise, 0.4mg of naloxone was injected intravenously and a further 1.6mg/hr of naloxone was continuously infused during exercise. Blood samples were collected after 60 minutes bed rest (Rest), at the time when the heart rates reached 150 bpm (Submax), the point of exhaustion (Max) during exercise and after 60 minutes bed rest following exercise (After 1hr). The levels of prolactin in serum, dopamine, beta-endorphin. VIP and ACTH in the plasma were measured. Whereas prolactin increased significantly at Submax (p less than 0.05) and Max (p less than 0.001), the increase in prolactin was suppressed by the administration of naloxone (p less than 0.05). Dopamine showed no remarkable change during exercise, with or without naloxone. There were significant increases in beta-endorphin at Max (p less than 0.001), VIP at Submax and Max (p less than 0.001), but these increases were suppressed by the administration of naloxone (p less than 0.001). ACTH which had markedly increased at Submax (p less than 0.025) and Max (p less than 0.001) showed a slight tendency to decrease following the administration of naloxone, but there were no significant differences in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[The significance of measurement of contents of serum serine protease inhibitors in senile dementia of the Alzheimer type].

We have evaluated serum alpha 1-antichymotrypsin content in dementia of the Alzheimer type (DAT). The subjects consisted of 26 patients with DAT, 15 with cerebrovascular dementia, 10 with mixed type dementia, 2 with Down syndrome, 17 with Parkinson disease, 14 with spinocerebellar degeneration, 14 with cerebrovascular disease without dementia, 12 with Duchenne muscular dystrophy and 77 normal controls. DAT group showed statistically significant increase of serum alpha 1-antichymotrypsin content, as compared with normal control group (p less than 0.001), mixed type dementia group (p less than 0.05) and other 6 groups (p less than 0.001). However, the levels of both alpha 1-antitrypsin content and inter-alpha-trypsin inhibitor content, included in serine protease inhibitors, were not significantly different between DAT and normal control groups. These findings indicated that measurement of serum alpha 1-antichymotrypsin is useful as the diagnostic marker of DAT.

Adult↗