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Biomedical subjects

K Kogure

Publications and source records attributed to K Kogure.

At least 433 records · Page 24Linked to original sources
PubMed1979

A tentative direct microscopic method for counting living marine bacteria.

Yeast extract (0.025%) and nalidixic acid (0.002%) were added to seawater samples and the samples were incubated for 6 h at 20 degrees C in the dark. Under these conditions, bacterial cells did not divide but grew to form elongated cells that are easily recognized by a direct microscopic method and epifluorescent microscopic technique. The number of cells thus obtained is proposed as a direct cound of viable bacterial cells (DVC). With open ocean samples, DVC was higher than 'viable' plate counts by up to three orders of magnitude and lower than the direct counts by about one order.

Bacteria↗
PubMed1979

The effects of transient candidemia on the brain: preliminary observations on a rodent model for experimental deep candidosis.

Deep candidosis was established in healthy uncompromised Wistar rats by injecting Candida albicans into the right internal carotid artery. Death of these animals could be produced within seven days by injecting 10(7) yeasts. The kidneys were most severely infected, and the entire brain was involved. No animal demonstrated leptomeningitis. Within one to two days microabscesses developed, subsiding into a histiocytic response in five to seven days. By seven days, chronic inflammation with noncaseating granulomas was seen. Throughout the study, cerebrospinal fluid and blood cultures failed to demonstrate the fungus. This rodent model is similar to human cerebral candidosis.

Animals↗
PubMed1978

A pictorial representation of endogenous brain ATP by a bioluminescent method.

The layering of a luciferin-luciferase solution on brain slices makes endogenous ATP visible. Rat brains, frozen in situ and sliced at 16 micrometer thickness at a temperature of--15 degrees C, were fixed by a ternary mixture of ethanol, formalin and dioxane at--20 degrees C for 15 min, and dried at 40 degrees C for 12 h. Luciferin, luciferase and a small quantity of magnesium sulfate were dissolved into an arsenate buffer solution containing 1% polyvinylpyrrolidone, 2% gelatin and 1% glycerol. The solution was then frozen into a column, sliced at 40 micrometer thickness at--15 degrees C and placed on the precooled brain slice. A luminiferous luciferin-ATP reaction begins when the brain slice reaches room temperature and persists for more than 10 min. This technique therefore makes possible the optical and/or photographic determination of the endogenous concentration of brain ATP. Capability of the technique is also demonstrated.

Adenosine Triphosphate↗
PubMed1978

The sequential uptake of (14C) deoxyglucose in brain after embolic stroke.

An i.v. bolus of (14C) deoxyglucose was injected into 4 groups of rats which simultaneously were embolized through the internal carotid artery. 15 and 30 min post embolization there was a massive decrease in (14C) deoxyglucose uptake in both deep and cortical structures. At 4 h a small zone of increased (14C) deoxyglucose uptake persisted around each embolized microsphere.

Animals↗
PubMed1977

Effect of insulin hypoglycemia upon cerebral energy metabolism and EEG activity in the rat.

Anesthetized ventilated rats were subjected to insulin-induced hypoglycemia (50 units/kg i.v.) while EEG, ECG, mean arterial pressure, blood gases, arterial pH and rectal temperature were controlled. Animals were sacrificed by rapid transcalvarial freezing of the brain in situ. Glucose, pyruvate and lactate were measured in blood, CSF and cortical tissue, in which additionally glycogen, phosphocreatine, ATP, ADP, AMP, aketoglutarate (aKG), glutamate, oxalacetate, aspartate, ammonia and water content were estimated. ATP/ADP ratio, energy charge (ECh) energy reserve, NADH/NAD+ quotient and intracellular pH were calculated. ECh does not correlate with either dysfunction of carbohydrate depletion, but declines in a threshold fashion when tissue glucose has fallen by over 97% and glycogen by over 60%. The EEG correlates with the degree and duration of carbohydrate depletion in cortical tissue. An isoelectric EEG occurs pari passu with the fall of the ECh. Increase in ammonia and decrease in aKG and Glut are supportive evidence of intrinsic substrate. Lactate decrease during hypoglymecia is not reversed by super-imposed hyqoxia.

Animals↗
PubMed1977

Sequential cerebral biochemical and physiological events in controlled hypoxemia.

Effects of controlled hypoxemia on cerebral functional activity were studied in rats using cyclic adenosine monophosphate (cAMP) and aminergic neurotransmitters in the brain tissue as special references. Evidence is presented that: (1) mild hypoxemic stress (PaO2 60 to 40 torr) may activate cerebral glycolysis with no evidence of anaerobic metabolism but that further reduction of PaO2 impairs cellular respiration, as evidenced by accumulation of glycolytic products; (2) glycogenolysis in the brain tissue, leakage of potassium ions from the brain cell, increase in brain water, and suppression of neural functional activity occur concomitant with accumulation of cAMP and prior to the fall of adenosine triphosphate; (3) the diminution of cerebral high-energy phosphates during hypoxia is associated with and may be caused by hypoxemia-induced neuroglycopenia and occurs at PaO2 15 torr; (4) induced hypoxemia per se does not affect the level or aminergic neurotransmitter substances in brain tissue.

Adenosine Diphosphate↗
PubMed1976

Spontaneous colon tumors in rats.

Twenty-eight cases of spontaneous colon tumors were found during autopsy of approximately 3,000 male W rats in our laboratories between 1968 and 1974. Macroscopically, these tumors were multiple and localized in the proximal part of the colon. Many nodules protruded on the serosal surface; polypoid tumors protruding into the lumen were rare. Microscopically, hyperplastic and adenomatous polyps were observed in the mucous membrane of the colon. There was adenomatous downward growth into the submucosal layer, and tubular-type adenocarcinomas invaded all the coats of the colon wall. Structural atypism was frequent and slight cell atypism was also present. Invasive tumors sometimes had an inflammatory reaction, and bacterial growth was observed within the neoplastic glands in thionine-stained sections. Escherichia coli and a gram-negative, facultative anaerobic bacillus, which grew only with E. coli in vitro, were isolated. A cultured epithelial cell line was established from one colon tumor. After a primary tumor was transplanted intraperitoneally into young adult rats, a mass grew in the peritoneal cavity for 4 months. The tumor incidence seemed higher at different times in the animals examined.

Adenocarcinoma↗
PubMed1976

[Clinical studies with amoxicillin (Pasetocin) (author's transl)].

This paper describes briefly the results obtained with AMPC (Pasetocin) administered by oral route to 21 patients with infection of the respiratory tract. 1. There was no difference in therapeutic effect on infection of the respiratory tract between daily dosages of 1,000 mg and 750 mg (the former was orally given in 4 divided doses every 6 hours a day and the latter in 3 divided doses after meal). The response of the patients to AMPC was remarkable or satisfactory. 2. Acute aggravation symptoms associated with chronic infection of the respiratory tract showed similar improvement to single acute infection of the respiratory tract. 3. The patients presenting acute aggravation symptoms received treatment for chronic stage consisting of consecutive oral administration of AMPC (500 approximately 750 mg a day) and their prognosis was favorable. Side effects attributable to prolonged treatment were not noted. 4. The incidence of side effects can be reduced largely by rejecting form AMPC therapy the patients who are hypersensitive to drugs including penicillins.

Adolescent↗
PubMed1975

Catecholamines in experimental brain ischemia.

Local cerebral ischemia was produced in rats by internal carotid artery injection of 35 mu carbon microspheres, and brain norepinephrine (NE), dopamine, and cyclic adenosine 3, 5-monophosphate (cAMP) were measured in embolized and intact hemispheres at intervals up to four hours. Sham-operated animals were controls. There was an instantaneous increase of cAMP. Norepinephrine was reduced within two minutes after embolization and remained low for four hours. Dopamine increased by five minutes after embolization and returned to normal after four hours. Results were qualitatively similar, but less, in the nonembolized hemisphere. Accumulation of cAMP is thought to be due to a direct effect of ischemic hypoxia and may be the initiating factor in increased glycolysis that occurs in ischemia. Decrease in NE may be secondary to its generalized release from presynaptic terminals throughout the brain and could be a factor in cortical vasocontriction that follows embolization. Dopamine changes are a reflection of alterations in energy metabolism.

Animals↗
PubMed1975

Changes in pepsinogen isozymes in stomach carcinogenesis induced in rats by N-methyl-N'-nitro-N-nitrosoguanidine.

Changes in the isozymes of pepsinogen (Pg) separated from the glandular stomachs of rats were studied by polyacrylamide gel electrophoresis during carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), from the beginning of MNNG administration to 3 months after the end of its 7-month regimen. In 13 of 25 rats killed successively, one (Pg 1) of the three pepsinogen isozymes (Pg 1, 3, 4) normally present in the pyloric mucosa had decreased or disappeared. It decreas was observed from 1 week after the beginning of MNNG treatment to at least 3 months after the end of the 7-month MNNG administration. Remarkable histopathologic changes were found from 8 months after MNNG was given, and rats showing such unusual histopathologic alterations also had changes in their pepsinogen isozyme pattern. In 4 of 27 rats, two (Pg 1, 2) of the four isozymes of pepsinogen (Pg 1-4) in the fundic mucosa decreased or disappeared from 3 months after the beginning of MNNG treatment to at least 2 months after the end of its 7-month administration. Histopathologic changes induced by MNNG were not as remarkable in the fundic mucosa as in the pyloric mucosa.

Adenocarcinoma↗
PubMed1975

Effects of hypothermia and hyperthermia on brain energy metabolism.

The influence of elevated and reduced body temperatures upon the metabolic state of the brain was evaluated from the tissue concentrations of phosphocreatine (PCr) ATP, ADP and AMP and from the concentrations of glucose, lactate and pyruvate in immobilized and artificially ventilated rats anesthetized with 70% N2O. The results were compared to the results obtained in normothermic animals. It was found that rats with body temperatures of 32 degrees and 22 degrees C had the same brain tissue concentrations of high energy phosphates and the same adenylate energy charge as the controls, but hypothermia led to a progressive decrease of both cerebral and arterial lactate and pyruvate concentrations. A metabolic acidosis but no excess lactate appeared in the blood. At a body temperature of 42 degrees C, the metabolic pattern in the brain agreed with a state of hypoxia at a time when there was no sign of substrate depletion. Arterial blood showed excess lactate which may indicate an inadequacy of the oxygen supply also to other tissues.

Adenosine Diphosphate↗