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Biomedical subjects

K Shimoji

Publications and source records attributed to K Shimoji.

At least 163 records · Page 9Linked to original sources
PubMed1986

Brain injury improves survival of mice following brain ischemia.

Minor brain injury was inflicted with a small needle at 4 sites one week before the production of incomplete brain ischemia in the mouse. A bilateral carotid clamp was applied for 60 min under pentobarbital anesthesia, and the number of survivors at one week after the ischemic insult was compared with those in animals anesthetized only and those in a sham-operated group. The number of survivors in the brain-injured group was significantly higher than in the other two groups. The results suggest that anti-ischemic factors are released by the injured brain or that certain unknown protective mechanisms against ischemia become active following brain injury.

Anesthesia, General↗
PubMed1986

Naloxone attenuates hypoxic depression of ganglionic transmission.

The effect of the opioid antagonist naloxone on hypoxia-induced blockade of synaptic transmission in the superior cervical ganglion (SCG) of the rat was studied in vitro. Naloxone (6 X 10(-6) M or more) attenuated the hypoxia-induced blockade of synaptic transmission in the SCG. In addition, in the concentrations studied, naloxone itself had a blocking effect on ganglionic transmission that involved terminal sites of the preganglionic axons. These data suggest that the protective effect of higher doses of naloxone on the hemodynamic responses to hypoxemia or ischemia may originate at least in part from the attenuating effect of naloxone on the hypoxia-induced blockade of ganglionic transmission.

Action Potentials↗
PubMed1986

Effects of alcohol on the liver in HBsAg carriers.

The frequency of anti-HBe and the effects of alcohol on the liver were serologically and histologically assessed in 28 nondrinking HBsAg carriers (group I), 33 mildly drinking HBsAg carriers (group II), and 21 moderately to heavily drinking HBsAg carriers (group III). The frequency of anti-HBe was significantly different in these groups (p less than 0.001). The frequency of chronic active hepatitis was significantly less in group III than in groups I or II (p less than 0.05). The frequency of HBeAg-positive carriers with chronic hepatitis was significantly less in group III (p less than 0.02). Histologically, the patients in group II mainly showed viral hepatic changes, whereas the patients in group III chiefly revealed alcoholic changes. Micronodular cirrhosis and hepatocellular carcinoma were seen in group III alone. These results suggest that increasing alcohol consumption is related to increasing prevalence of seroconversion from HBeAg to anti-HBe and to increasing prevalence of alcoholic liver disease and decreasing prevalence of chronic hepatitis.

Adult↗
PubMed1985

Selective depression of hippocampal inhibitory postsynaptic potentials and spontaneous firing by volatile anesthetics.

The effects of halothane, isoflurane and enflurane on the rat hippocampal CA1 neurons in in vitro preparations were studied by intracellular recordings. All volatile anesthetics, at the concentrations which are likely to be in the range of clinical doses, depressed the IPSPs and the spontaneous firing without affecting the resting membrane properties and the EPSPs. The results suggest that the simultaneous blocking effects of the anesthetics on both the spontaneous firing and IPSPs are responsible for production of general anesthesia rather than their blocking actions on the EPSPs in terms of behavior of hippocampal neurons.

Anesthetics↗
PubMed1985

[Epidural spinal cord stimulation: its efficacy and mechanisms].

Pain-alleviating effects of epidural spinal cord stimulation (ESCS) were assessed in patients with chronic intractable pain including cancer pain, and some aspects concerning its mechanisms were discussed. The temporary ESCS with percutaneously inserted electrodes was employed in 105 patients, and the implantable systems for long-term use in 19 patients. The ESCS had satisfactory effects especially in patients suffering from cancer pain, causalgia, facial and nape pain. The conditioning stimuli applied to the cervical dorsal cord exhibited interactions with the segmentally evoked spinal cord potential (SCP). The N1 wave of the SCP was inhibited up to 120 ms, while the P2 wave was facilitated for more than 100 ms, suggesting that the presynaptic inhibitory action at the dorsal horn is responsible for mechanism of the ESCS. CSF concentration of norepinephrine was significantly decreased by the ESCS therapy, indicating the existence of the relationship between norepinephrinergic descending inhibitory system and the ESCS in pain-alleviating mechanism.

Adult↗
PubMed1984

Anesthetics block excitation with various effects on inhibition in MRF neurons.

The effects of isoflurane and halothane on the behavior of mesencephalic reticular neurons in the rat were studied by long-term extracellular microelectrode recording. Both anesthetics always suppressed the excitatory responses with simultaneous blocking or augmenting effects on the inhibitory responses of the reticular neurons. The blocking effects on the inhibitory responses were more frequently noticed during light anesthesia than during the deep stage.

Action Potentials↗
PubMed1984

Anesthetics and excitatory/inhibitory responses of midbrain reticular neurons.

The effects of nitrous oxide, halothane, ether, isoflurane, thiopental, and thiamylal on the excitatory as well as inhibitory responses of single neurons in the midbrain reticular formation (MRF), believed to be one of the most important sites for the regulation of wakefulness, were studied by long-term, extracellular microelectrode recording in cats and rats. All anesthetics except nitrous oxide suppressed the excitatory responses of MRF neurons evoked by somatosensory stimulation. The inhibitory responses markedly were potentiated by both barbiturates but variously affected by other inhalation anesthetics. Blockade of the inhibitory responses (disinhibition) was observed more frequently with the inhalation agents during the light state of anesthesia. Thus, suppression of excitatory responses is likely to be a general feature of the anesthetic state in terms of the behavior of MRF neurons. Further, potentiation of the inhibitory responses might be characteristic of barbiturate anesthesia.

Anesthetics↗
PubMed1984

[Effectiveness of ceftizoxime on various infections in patients with underlying diseases].

Ceftizoxime (CZX), a parenteral cephalosporin derivative belonging to the so-called third generation cephalosporin is reported to have a broad antibacterial activity, particularly against Gram-negative aerobic bacilli and some anaerobes, such as Bacteroides fragilis and a good stability to beta-lactamases. Clinical study was performed on a total of 20 cases, 9 females (1 case had urinary tract infection 3 times) and 11 males, aged from 27 to 82 years. All patients had the underlying diseases. They were bronchial asthma in 3 cases, influenza in 1, chronic pulmonary emphysema in 1, pulmonary fibrosis in 1, chronic bronchitis with strongyloidiasis in 1, lung cancer in 3, esophagus cancer in 2, stomach cancer in 1, hepatoma with urolithiasis in 1, liver cirrhosis with diabetes mellitus in 1, alcoholism with strongyloidiasis in 1, cholelithiasis in 1 and congestive heart failure in 1, respectively. Clinical diagnoses for infections were 2-acute bronchitis, 2-exacerbation of chronic bronchitis, 2-broncho-pneumonia, 2-pneumonia including one suspected case, 1-obstructive pneumonia, 2-secondary pulmonary infection, 1-pulmonary infection, 3-urinary tract infection (UTI), 1-UTI with sepsis, 1-sepsis, 1-sepsis with purulent meningitis, 1-biliary tract infection and 1-infected bronchoesophageal fistula. CZX was given by intravenous drip infusion, at a dose of 1 to 2 g, twice daily for 3 to 15 days. Because of severity in infections and underlying diseases, some cases were treated either steroid, gamma-globulin preparations or other antibiotics in combination with CZX. Twelve out of 15 cases assessed clinically responded satisfactorily to the treatment and efficacy rate was 80.0%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Synthesis and 5-lipoxygenase inhibitory activities of eicosanoid compounds.

Ten eicosanoid compounds (3, 6, 9, 11, 12, 15, 18, 21, 23, and 25), methyl (6E,8Z,11Z,14Z)-5-hydroxy-6,8,11,14-eicosatetraenoate (5-HETE, 10), leukotriene A4 (26), and (5S,6E,8E,10E,12RS,14E)-5,12-dihydroxy-6,8,10,14-eicosatetraenoic acid (5,12-diHETE, 27) were prepared and their inhibitory activities against the 5-lipoxygenase from guinea pig polymorphonuclear leukocytes (PMNL) were tested. 5,6-Methanoleukotriene A4 (18) was especially a potent and specific inhibitor of the 5-lipoxygenase without inhibiting the cyclooxygenase and the 12-lipoxygenase. Leukotriene A4, 5-HETE, and 5,12-diHETE also have inhibitory activities against the 5-lipoxygenase at micromolar concentrations, which can regulate the formation of slow-reacting substance of anaphylaxis intracellulary.

Animals↗