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Biomedical subjects

M Kudo

Publications and source records attributed to M Kudo.

At least 307 records · Page 17Linked to original sources
PubMed1990

[Prostaglandin D2-endogenous regulator of physiological sleep-inhibited CRF-induced ACTH secretion from rat anterior pituitary cells].

Delta sleep-inducing peptide (DSIP) is described as being an endogenous sleep factor. This DSIP inhibits ACTH release induced by CRF from rat anterior pituitary tissue. Prostaglandin D2 (PGD2) is regarded as another endogenous sleep factor. However, little information has been accumulated concerning the involvement of PGD2 in the regulation of hormone secretion from the anterior pituitary. It was, therefore, interesting to observe the effect of PGD2 on ACTH release from rat anterior pituitary cells. Rat anterior pituitary cells were obtained by enzymatic digestion of the pituitary gland of male Wister rats. The cell pellet was suspended in Hank's balanced salt solution containing 0.1% BSA and distributed in a 800 microliter aliquot to 12 x 75mm glass tubes. The samples were preincubated for 90 min. in a 37 degrees C waterbath under 5% CO2/95% O2. After preincubation, aliquots of various concentrations of CRF, PGD2 and PGE2 were added in a 100 microliter volume and incubated for 4 hr. ACTH in the incubation medium was determined by radioimmunoassay. 0.01-1.0nM CRF significantly increased the ACTH release from rat anterior pituitary cells in a dose dependent manner. Each concentration of 0.1, 1, 2nM PGD2 or PGE2 had no effect on basal ACTH levels. 2nM PGD2 showed a significant inhibition of the CRF-induced ACTH secretion from rat anterior pituitary cells. Similarly, 2nM PGE2 significantly inhibited the CRF-induced ACTH release from rat anterior pituitary cells. The magnitude of the inhibitory effect of PGE2 was slightly higher than that of PGD2. From these results, we concluded that PGD2 inhibited CRF-induced ACTH secretion at the level of pituitary gland.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1990

Differential organization of crossed and uncrossed projections from the superior olive to the inferior colliculus in the mole.

Projections from the medial (MSO) and lateral (LSO) superior olivary nuclei to the inferior colliculus (IC) were examined in the mole. In each mole, Fluoro-Gold was injected into one IC and wheat germ-agglutinated horseradish peroxidase (WGA-HRP) into the other IC; most MSO neurons were double-labeled bilaterally, while most LSO neurons were single-labeled bilaterally. The results indicate that the bilateral projections from the MSO and LSO to the IC are mainly established by single MSO neurons with axon collaterals to the IC on both sides, and by two separate populations of LSO neurons with axons to the contralateral or ipsilateral IC.

Animals↗
PubMed1990

Auditory brainstem in the mole (Mogera): nuclear configurations and the projections to the inferior colliculus.

Anatomical organization of the central auditory system in the mole was studied at the lower brainstem levels. The cyto-, myelo-, and chemoarchitectures were examined in Nissl, myelin, and acetylcholinesterase stained materials, and then the origins of the ascending afferents to the inferior colliculus (IC) were identified by injecting wheatgerm agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the unilateral IC and processing the tissue according to the standard retrograde tracing techniques. The results indicate that the auditory nuclei and pathways in the lower brainstem of the mole conform to the basic plan common to many other mammals. Nevertheless, several characteristic features are evidenced in the present study: (1) in the cochlear nucleus (CochN), granule cell fields are very large in both the ventral (VCN) and dorsal (DCN) nuclei; among several populations of neurons, fusiform cells in the DCN, multipolar cells in the VCN and DCN, and small spherical cells in the VCN project to the IC directly, (2) in the superior olivary complex (SOC), the medial nucleus (MSO) is well developed in comparison with that in the hedgehog, the opossum, the mouse, and the rat, although the general configuration of the SOC is similar to that in those mammals, most strikingly, the MSO projects to the IC bilaterally in the mole, and (3) the nuclei of the lateral lemniscus (NLL) show a great development and consist of three well-differentiated parts of the dorsal, intermediate, and ventral nuclei. The projections from these subnuclei to the IC conform to the basic mammalian plan.

Animals↗
PubMed1990

Monosynaptic projection from the pedunculopontine tegmental nuclear region to the reticulospinal neurons of the medulla oblongata. An electron microscope study in the cat.

The magnocellular reticular nucleus (MRN) of the cat was observed electron microscopically following the combined application of kainic acid into the pedunculopontine tegmental nuclear region (PPN region) and horseradish peroxidase conjugated to wheat germ agglutinin (WGA-HRP) into the spinal cord. Some degenerating axon terminals arising from the PPN region were found to make synaptic contacts with retrogradely HRP-labeled reticulospinal neurons in the MRN.

Animals↗
PubMed1990

Effect of Triton X-100 in the Golgi-Kopsch method.

Application of a detergent, Triton X-100, dramatically increased the number of impregnated neurons in the Golgi-Kopsch method. This modification is particularly useful for obtaining a panorama of the neuronal field in adult brains.

Animals↗
PubMed1990

Laminar organization of the substantia nigra pars reticulata in the cat.

Using a semihorizontal section plane tangential to the ventral surface of the cerebral peduncle, the authors re-examined cyto-, myelo- and dendroarchitecture, acetylcholinesterase activity, afferent fibers, and efferent projection neurons of the substantia nigra pars reticulata. In the semihorizontal section plane, the substantia nigra pars reticulata was a disc-shaped nucleus and contained two to three myelinated fiber bundles running from anteromedial to posterolateral. Bands of high acetylcholinesterase activity existed parallel to the anteromedial-posterolateral direction. The Golgi silver impregnation study revealed that many nigral neurons extended their varicose dendrites anteromedially and posterolaterally. In cases with injections of wheat germ agglutinated horseradish peroxidase into the neostriatum or injections of tritiated leucine into the subthalamic nucleus, anterogradely labeled afferent fibers and axon terminals in the substantia nigra pars reticulata were organized into bands in the same anteromedial-posterolateral direction. In cases with injections of wheat germ agglutinated horseradish peroxidase into either the superior colliculus, the pedunculopontine tegmental nucleus or the ventromedial nucleus of the thalamus, retrogradely labeled neurons were also clustered along the anteromedial-posterolateral direction with their dendrites extending anteromedially and posterolaterally. The present findings strongly suggest that the substantia nigra pars reticulata has a laminar organization.

Animals↗
PubMed1990

Kallikrein- and prolactin-producing cells in the rat anterior pituitary are the same.

Kallikrein-positive cells in the anterior pituitary of female rats were identified to be the same as prolactin-producing cells by using an immunoelectron microscopic method. The kallikrein immunoreactivity was localized at the Golgi apparatus, the rough endoplasmic reticulum, and secretory granules, suggesting that kallikrein is synthesized in the prolactin-producing cells and also may be secreted into the blood vessels.

Absorption↗
PubMed1990

Ganglioglial differentiation in medulloblastoma.

A case of cerebellar medulloblastoma with clusters of mature ganglion cells and glial cells is described. The patient, a 15-year-old girl, underwent three operations followed each time by radiation and chemotherapy during the four-year clinical course. Histologically, the ganglion cells were clearly identifiable by their abundant eosinophilic cytoplasm, round nuclei with prominent nucleoli, tigroid granules, and argyrophilic fibrils and axons. Immunohistochemically, the cells were NSE- and NF-positive, and ultrastructurally they contained abundant tubules and filaments, neurosecretory granules and well developed rough endoplasmic reticulum. There were many cells transitional in appearance between primitive cells and mature ganglion cells. The tumor also had many mature yet atypical astrocytes and oligodendrocytes. The exact mechanism of the extensive neuronal and glial maturation of medulloblastoma cells is unclear, but the repetitive surgical interventions, radiation and chemotherapy might have had certain cytostatic effects on rapidly dividing medulloblastoma cells, giving them a chance to mature into postmitotic cells with potential for neuronal and glial differentiation.

Adolescent↗
PubMed1990

[Survey on clinical isolates from 13 hospitals in Akita Prefecture--changes in frequency and susceptibility of isolates by scale of hospital. Survey Group for Clinical Isolates, Chemotherapy Research Committee of Akita Prefecture].

Isolates from various clinical materials in 13 hospitals in Akita prefecture and their drug susceptibility were investigated by the Chemotherapy Research Committee of Akita Prefecture during the period from Dec., 1987 to Feb., 1988. The results were as follows: 1. The total number of isolates was 8,387, including Staphylococcus aureus (18.9%), Pseudomonas aeruginosa (10.9%), Staphylococcus epidermidis (7.3%) and Enterococcus faecalis (6.6%). S, aureus and P. aeruginosa were detected more frequently in the larger hospitals. 2. The detection frequency of S. aureus from the sputum, throat swab and pus exudate was also very high. There was a diversity in isolates from the urine and the frequency of Escherichia coli was low. More than half of the isolates from the blood were S. epidermidis and S. aureus. Many kinds of bacteria were detected from pleural fluid and ascites, but the isolate showed no particular tendency. 3. The susceptibility of S. aureus to oxacillin were variable in hospitals, and the susceptibility to cefazolin were even lower. Low susceptibility were also seen with norfloxacin. S. aureus showed the highest susceptibility to minocycline. The susceptibility was lower for inpatients than for outpatients. P. aeruginosa showed low susceptibility to cefsulodin. The number of ampicillin-resistant Haemophilus influenzae isolates tended to decrease. Enterobacter cloacae showed a low susceptibility for cephems. Serratia marcescens showed low susceptibility to many drugs. Based on the above results, we concluded that attention should be paid to S. aureus, P. aeruginosa and Enterobacter in clinical practice.

Anti-Bacterial Agents↗
PubMed1990

Endothelin receptor is coupled to phospholipase C via a pertussis toxin-insensitive guanine nucleotide-binding regulatory protein in vascular smooth muscle cells.

The mechanisms of endothelin-1 (ET) actions were investigated in cultured rat aortic vascular smooth muscle A-10 cells. The A-10 cells have a single class of high affinity binding sites for ET with an apparent Mr of 65,000-75,000 on SDS-PAGE. Stimulation of cells with ET induces mobilization of Ca2+ from both intra- and extracellular pools to produce a biphasic increase in cytoplasmic free Ca2+ concentration. ET increases cellular levels of inositol trisphosphate and 1,2-diacylglycerol, indicating activation of phospholipase C by ET. ET stimulates production of inositol phosphates in membranes prepared from A-10 cells in the presence of guanosine 5'-O-(thiotriphosphate) (GTP gamma S), but not in its absence. Further, specific binding of 125I-labeled ET to A-10 cell membranes is shown to be inhibited by GTP gamma S in a dose-dependent manner. Treatment of A-10 cells with pertussis toxin induces ADP-ribosylation of a 41,000-D membrane protein but fails to block the ET-induced increases in inositol phosphate production and Ca2+ mobilization. These results indicate that the receptor for ET is coupled to phospholipase C via a guanine nucleotide-binding regulatory protein which is distinct from the pertussis toxin substrate in A-10 cells.

Animals↗
PubMed1990

Immunohistochemical localization of kallikrein within the prolactin-producing cells of the rat anterior pituitary gland.

The localization of tissue kallikrein in the pituitary gland of rats was investigated by an immunohistochemical technique using antiserum against rat urinary kallikrein. Kallikrein-positive cells were detected in the anterior lobe of the pituitary of both male and female rats, but were not observed in the posterior lobe of the pituitary in either sex. The kallikrein-positive cells in the anterior pituitary of female rats in oestrus were found to correspond to the prolactin-producing cells, whereas the cells producing GH, LH and ACTH were negative for kallikrein. It is possible, therefore, that the tissue kallikrein may be involved in the production of prolactin and not that of the other anterior pituitary hormones, such as GH, LH, FSH, ACTH and TSH.

Animals↗
PubMed1990

[Two cases of pulmonary alveolar proteinosis with increased CEA].

Two cases of pulmonary alveolar proteinosis (PAP) with increased CEA were reported. Case 1 was a 62-year-old male with suspected pulmonary fibrosis, who was transferred to our hospital. Laboratory findings on admission revealed 31.3 ng/ml of CEA. Because he had severe dyspnea, lung biopsy was not carried out. His condition gradually deteriorated and he died of respiratory failure. Autopsy revealed he had PAP and no malignancy. Case 2 was a 48 year-old male referred to our hospital because of dyspnea. Serum CEA was 52.8 ng/ml. Microscopic examination of a transbronchial lung biopsy showed PAP. The level of CEA in bronchoalveolar lavage fluid was 151 ng/ml. Unilateral whole lung lavage was performed twice. With the improvement of chest X-ray findings, serum levels of CEA fell to normal level. The molecular weight of CEA in bronchoalveolar lavage fluid was 180,000. Immunochemical staining of CEA in lung revealed nonspecific findings.

Carcinoembryonic Antigen↗
PubMed1990

[The changes in total body water in patients with prolonged anesthesia and surgery].

We studied the influence of prolonged anesthesia and surgery on total body water (TBW) with tetrapolar bioelectrical impedance analysis (BIA). Eight patients who underwent prolonged anesthesia were selected as the subjects of the study and were compared with nine patients who underwent surgery of less than 3 hours. Plasma hormone concentrations were also examined. In the prolonged anesthesia patients, TBW increased significantly as compared with those of the patients who underwent short surgery (P less than 0.05). TBW showed the most remarkable increase on the first post operative day. Plasma ADH and aldosterone concentrations increased in the patients of both groups. However, we could not find a significant relationship between TBW and plasma hormone concentrations. BIA seems to be a useful method to estimate TBW during perioperative periods. However, further detailed investigation would be necessary to obtain a reliable technique in such an unstable condition.

Adult↗
PubMed1990

[Reaction products of sevoflurane with components of sodalime under various conditions].

Sevoflurane is reported to react with sodalime to resolve into several products. We examined the reaction products of sevoflurane when this anesthetic reacted with components of sodalime under various conditions. Analysis of reaction products was performed by gas chromatography using a 2m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime in a test tube at room temperature, only P1 was detected and all reaction products of P1 to P5 were identified when the test tube was heated at 50 degree C for 3 hours. Sodalime contains Ca (OH)2, NaOH, KOH and silicon dioxide. Reaction of sevoflurane with KOH produced P1 to P5 products even at room temperature. After the reaction of sevoflurane with NaOH or Ca (OH)2 at 50 degrees C, P1 to P5 or P1 only were detected on the chromatogram respectively. No peak of any reaction products was obtained after the reaction with silicon dioxide under various conditions. These results suggest that hydroxy group of sodalime component would increase reaction products of sevoflurane.

Anesthetics↗
PubMed1990

[Accurate and simplified determination of ketamine in plasma by gas chromatography mass spectrometry].

An accurate and simplified method has been developed for determination of ketamine in human plasma using gas chromatography and electron impact mode mass spectrometry with selected ion recording from 0.5ml of plasma. Standards and samples of plasma underwent the same procedure of two step extraction by methanol. Ketamine concentrations in the plasma were determined from the peak in the selected ion profile of ketamine (m/e: 237). Standard curve was linear with the increasing amount of ketamine (0.63-5.0 micrograms.ml-1) in plasma with mean CV = 5.2% mean RR = 63.8% and r = 0.998. The concentration of ketamine in plasma ranged from 1.6 micrograms.ml-1 to 2.5 micrograms.ml-1 during ketamine anesthesia (2mg.kg-1.h-1) in a surgical patient.

Gas Chromatography-Mass Spectrometry↗
PubMed1990

[Reaction products of sevoflurane with new soda lime-A under various conditions].

Sevoflurane is reported to react with sodalime, a common carbon dioxide absorber which resolves into several products. We measured the reaction products of sevoflurane when this anesthetic reacted with sodalime-A, a new carbon dioxide absorber under various conditions. Analysis of reaction products was done by gas chromatography using a 2 m column packed with DOP. Six peaks including sevoflurane were detected on the gas chromatogram of sevoflurane after reaction with sodalime-A and five reaction products were obtained. These peaks were from P1 with the shortest retention time to P5 with the longest retention time. When sevoflurane was sealed with sodalime-A in a test tube at room temperature, 40 degrees C and 45 degrees C, only P1 was detected and two reaction products of P3 and P5 were identified when the test tube was heated at 50 degrees C. Sodalime contains Ca(OH)2, NaOH, KOH and silicon dioxide, and sodalime-A contains Ca(OH)2 and NaOH only. We reported previously that sevoflurane reacted with KOH to produce P1 to P5 even at room temperature and KOH was the most contributing factor to produce these reaction compounds. Reaction products of sevoflurane with two types of carbon dioxide absorber were checked with gas chromatography. Degradation products except P1 with sodalime-A was less than with conventional sodalime at any conditions. P1 production was about twice to three times more than that with sodalime.

Anesthetics↗
PubMed1990

[Plasma catecholamine levels following continuous epidural infusion of morphine for postoperative analgesia in surgical patients].

Plasma catecholamine levels were measured to evaluate postoperative pain relief either with epidural morphine or systemic analgesics in sixteen patients who underwent gastrectomy. Eight patients (epidural morphine group) obtained postoperative analgesia with continuous epidural morphine with a pump (CADD-PCA, Model 5200P, Pharmacia). A bolus of morphine was administered through an indwelling thoracic (Th8 X 9) epidural catheter 3 hrs prior to the proposed end of the surgery, which was followed with continuous epidural infusion of morphine at a rate of 0.167-0.042mg.hr-1 by the pump during and after anesthesia and surgery with gradual decrease in dose until the third postoperative day. The remaining eight patients (systemic analgesics group) received repeatedly intravenous or intramuscular pentazocine and buprenorphine when needed. Plasma epinephrine levels increased significantly at the end of surgery in both groups, and were higher in the systemic analgesics group than those in the epidural morphine group. In the epidural morphine group, the catecholamine levels decreased to the previous day's levels on the first postoperative day and afterward, but remained high during three postoperative days in the systemic analgesics group. Plasma norepinephrine levels increased significantly at the end of surgery and afterward in both groups. However, they were significantly higher in the systemic analgesics group than in the epidural morphine group. Plasma dopamine levels were unchanged in the epidural morphine group during the surgical procedures, but they increased significantly on the first postoperative day and thereafter in the systemic analgesics group. Our study suggests that continuous epidural infusion of morphine is adequate for postoperative pain relief and exerts a suppressing effect on plasma catecholamine levels as compared with systemic analgesics regimen.

Adult↗