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Biomedical subjects

T Komatsu

Publications and source records attributed to T Komatsu.

At least 361 records · Page 20Linked to original sources
PubMed1982

Common and plantar warts with trichilemmal keratinization-like keratinizing process: a possible existence of pseudo-trichilemmal keratinization.

Thirty-one common and five plantar warts were investigated histopathologically and electron microscopically in order to reveal whether or not these warts keratinize in a fashion similar or identical to trichilemmal keratinization (TK). Histopathologically, parts of 12 of 31 common, and 3 of 5 plantar warts, exhibited varying keratinization similarities to TK. The most similar case showed changes almost identical to intrinsic TK. Electron microscopy revealed uneven and somewhat interdigitating borders between the keratinized and the keratinizing cells, with a few ladder-like membrane coating granules. It is postulated that there may be TK or TK-like keratinization without any relationship to the outer root-sheath of the hair follicle. We propose the concept of pseudo-TK to distinguish this type of keratinization from intrinsic TK.

Epithelium↗
PubMed1982

The mechanisms of synergistic effect of antibiotics. A mechanism of synergism, cephaloridine with gentamicin on cephaloridine resistant gram negative bacilli.

Twelve strains out of 75 Gram negative rods, which were isolated at the clinical laboratory in the hospital, were highly resistant to cephaloridine (CER) and relatively sensitive to gentamicin (GM). Nine strains out of the 12 strains revealed synergistic effect when small doses of GM were used together with CER. A mechanism of synergistic effect on Enterobacter cloacae, 1 strain of the 9 strains, was studied through change of beta-lactamase activities. The levels of viable cell count decreased when small doses of GM were added compared with the ones obtained without the addition of GM. Similarly the levels of protein concentration and beta-lactamase activities in the sonicated component of sediment decreased, so did the level of beta-lactamase activities per cell. On the contrary, however, the beta-lactamase activities in the supernatant fluid showed no difference irrespective of the GM. Based upon the above mentioned findings, it is suggested that synergistic effect of CER and GM might be due to inhibition of protein synthesis as well as due to subsequent inhibition of beta-lactamase synthesis. This is compared with the author's previous study, in which the mechanism of synergistic effect of CER and chloramphenicol (CP) was partly due to inhibition of protein synthesis, but mostly due to inhibition of beta-lactamase synthesis.

Bacteria↗
PubMed1982

[Side effects of metrizamide (Amipaque) cervical myelography (author's transl)].

Thirty-four patients were submitted to the conventional cervical myelography by administration of metrizamide (Amipaque) through three routes (lumbar 23, suboccipital 6, C1-C2 lateral 5). After the injection of metrizamide (4-11 ml, 170-250 mgI/ml), all procedures of the cervical myelography were done as soon as possible within 9 minutes. The adverse reactions of Amipaque were observed in 29 cases (85%) out of 34 cases initially 1 hour after cervical myelography and disappeared completely in an average of 16 hours. The total number of the side effects was 140 incidences such as meningeal irritation (headache 18, nausea 17, vomiting 17), cerebellar signs (dizziness 11, dysarthria 8, tremor 5, bradylalia 2, dysmetria 2, tipsy feeling 2, dysdiadochokinesis 1), autonomic signs (flushing 7, pale face 4, fever 4, sweating 2, hiccup 2, fatigability 2, micturition disturbance 1), sensory signs (exacerbation of numbness 6, perioral numbness 3, back pain 1, chest pain 1), motor signs (focal muscle spasm 5, exacerbation of paresis 4, areflexia 1), psychiatric signs (dysphasia 3, disturbance of consciousness 2, euphoria 1, persecutory delusion 1) and muddiness 7. We observed that waxing and waning of side effects correlated tightly with transient cortical penetration of dye in CT and cortical dysfunction mainly slowing of the background activity and slow wave burst in EEG. According to high frequency of side effects in our study, we suggest that a greater incidence of side effects may result when high concentration of Amipaque comes in contact with the cerebral cortex by using an inadequate fluoroscopic table which has only fixed one plane image and rough positioning control. Slow absorption into blood stream may affect appearance and maintenance of side effects. In order to decrease side effects after Amipaque cervical myelography, we propose that we should introduce a mobile rotating chair coupled with high power image and chose C1-C2 lateral route using 1500-1700mgI of Amipaque.

Adolescent↗
PubMed1981

Antigenic analysis of polioviruses isolated from a child with agammaglobulinemia and paralytic poliomyelitis after Sabin vaccine administration.

A 3-year-old boy with agammaglobulinemia developed paralytic poliomyelitis on day 553 after being fed poliovaccine. Non-vaccine-like type 2 polioviruses were isolated from 22 stools obtained within 684 days after the onset of illness. Antigenic variations were observed among these viruses. The non-vaccine-like virus isolated 1 week after the onset of paralysis differed in virulence from the Sabin type 2 vaccine strain in the neurovirulence test in monkeys, and did not have the same antigenic character as the wild virulent strains. Another virus isolated on day 348 before the onset of illness was also classified as non-vaccine-like. However, the Sabin type 2 strain was shown to be homologous with this strain by the McBride test. Some Sabin-like particles were found in this stock virus. We may conclude that the non-vaccine-like virus isolates were derived from Sabin vaccine by antigenic variation that occurred during long-term multiplication in the intestinal tract.

Agammaglobulinemia↗
PubMed1981

Pentobarbital-anesthetized and decerebrate cats reveal different neurological responses in anesthetic-induced analgesia.

Cats were used to assess the significance of differences in animal preparations in the study of anesthetic-induced analgesia. Comparison was made between pentobarbital-anesthetized and decerebrate non-anesthetized cats. Bradykinin dissolved in normal saline was injected into the femoral artery as a noxious stimulus, and the neural response in the spinal cord lateral funiculus was recorded using the multi-unit activity technique. The magnitude of the neural response and the changes in spontaneous firing were compared before and after cervical cord transection at C1. Before the transection, the response was greater in anesthetized than in decerebrate cats. The cord transection potentiated the response in both preparations, but the degree of potentiation was greater in decerebrate than in anesthetized cats. These studies confirmed the presence of a descending pain inhibition system acting tonically on the nociceptive neural mechanisms in the spinal cord, and indicated the susceptibility of this system to pentobarbital. We conclude that pretreatment with pentobarbital induces pharmacologically a state of partial spinal cord transection and reduces the effects of drugs acting through supraspinal CNS structures.

Animals↗
PubMed1981

Activation of the supraspinal pain inhibition system by ketamine hydrochloride.

The neurophysiologic mechanism of ketamine-induced analgesia was studied in cats under conditions of electrolytic decerebration or pentobarbital anesthesia. Injection of bradykinin into the femoral artery served as the noxious stimulus and the neural response in the lateral funiculus of the spinal cord was recorded by the multi-unit activity technique. Ketamine depressed the bradykinin-induced response more markedly in decerebrate, non-anesthetized cats than in pentobarbital-anesthetized cats. The depressant action disappeared following cervical cord transection at C1, in both decerebrate non-anesthetized and pentobarbital-anesthetized cats. Thus the analgesic action of ketamine is probably exerted mainly through activation of the supraspinal pain inhibition system and a direct action on the spinal cord nociceptive neural mechanism, if any, is slight. The excitatory action of ketamine on the supraspinal pain inhibition system is susceptible to the depressant action of pentobarbital.

Animals↗
PubMed1981

Antianalgesic action of thiamylal sodium in cats.

The effects of thiamylal on the nociceptor-driven neural activity in the spinal cord were studied in decerebrate, non-anesthetized cats. Noxious stimulation was induced by the injection of bradykinin into the femoral artery and the neutral response in the lateral funiculus was measured by the multi-unit activity technique. The effects of thiamylal on the bradykinin-induced response were compared before and after the spinal cord transection, above the recording site. Thiamylal, 5 mg/kg i.v., potentiated the response significantly before the cord transection and depressed it after the transection. These findings indicate that the antianalgesic action of thiamylal is induced at the spinal cord level: although this anesthetic agent does have a direct intraspinal depressant action, the multisynaptic neural network of the supraspinal pain inhibition system is more susceptible to the actions of anesthetics, and the depression of this descending system by thiamylal results in a release of spinal cord nociceptive neural mechanisms from the supraspinal control.

Animals↗
PubMed1981

Naloxone does not antagonize the anesthetic-induced depression of nociceptor-driven spinal cord response in spinal cats.

The effects of several anaesthetics on spinal cord nociceptive neural mechanisms and their interactions with the opiate antagonist, naloxone, were studied in acute, spinal cord transected cats. Intra-arterial injection of bradykinin was used as the noxious test stimulus. Spontaneous activity and the neural response induced by bradykinin were recorded by the multi-unit activity technique in the lateral funiculus of the spinal cord. Naloxone, 0.1 or 2.0 mg/kg i.v. had little effect on the bradykinin-induced response, but enhanced the spontaneous firing of the lateral funiculus significantly. Fentanyl, 30 micrograms/kg i.v., depressed both the bradykinin-induced response and spontaneous firing. These effects of fentanyl were antagonized completely by naloxone, 0.1 mg/kg i.v. Nitrous oxide, thiamylal, halothane and ether depressed the bradykinin-induced response considerably, but it was not antagonized by naloxone, 0.1-2.0 mg/kg i.v. Enflurane had little effect on the bradykinin-induced response. The effects of these anesthetics on spontaneous firing were divergent: nitrous oxide enhanced it while other drugs depressed it, to various degrees. All these data suggest that the neural and/or neurochemical mechanisms of anesthetic-induced analgesia differ from mechanisms related to opioids.

Anesthetics↗
PubMed1981

[Two cases of natural infection of Angiostrongylus cantonensis in cynomolgus monkeys (Macaca fascicularis) (author's transl)].

Two of 80 cynomolgus monkeys, Macaca fascicularis, imported from Indonesia showed weakness, anorexia, paralysis of extremities and dysstasia. The blood test conducted at the time of autopsy proved that the white blood cell count markedly decreased in both cases and the blood urea nitrogen content increased in Case No. 1. In Case No. 2, a high blood sugar value, a low red blood cell count and a low hematocrit value were recognized. Histologic examinations revealed the presence of fragments of a nematode in the subarachnoid space of the cerebrum, granular layer of the cerebellum and gray matter of the cervical spinal cord. The findings of eosinophilic meningitis, necrosis, foreign body giant cells and cellular infiltration predominantly with eosinophils were also noted there. Morphological features of the nematode found in the tissue sections were identical, in all respects, with those described by predecessors who made morphological observations on the cross sections of Angiostrongylus cantonensis. Immunoelectrophoretic analyses of sera from these monkeys demonstrated the presence of band "a", which has been described to be highly specific to human A. cantonensis infection. Based on the above-mentioned evidences, the parasite fragments found in the histological sections from the monkeys were identified as A. cantonensis. The cases of natural infection reported herein represent the first, to our knowledge, in which migration of A. cantonensis larvae in the central nervous system of monkey was demonstrated. The present observation suggests applicability of simian angiostrongyliasis as a model for infections in man.

Angiostrongylus↗
PubMed1981

Binding of antibiotics to human liver glutathione S-transferases.

Glutathione S-transferases (GSH S-transferases) are multifunctional enzymes and are known to play an important role as intracellular binding protein in human liver. Binding of several antibiotics, including cefotetan, benzylpenicillin, cefazolin, chloramphenicol and gentamicin, to cationic and anionic GSH S-transferases isolated from human liver, and to human serum albumin, has been investigated by using the centrifuge column technique, which is supposed to be an excellent one for its sensitivity and rapidity in ligand binding studies. The dissociation constants (Kd) of the antibiotics for human liver GSH S-transferases and for human serum albumin, and the number of binding sites for the antibiotics on a molecule of human liver GSH S-transferases and of human serum albumin have been evaluated by means of Scatchard plots. This study has shown that cefotetan is bound to cationic GSH S-transferases to the greatest extent, followed by benzylpenicillin, cefazolin and chloramphenicol, gentamicin being bound to the smallest extent. It has been confirmed that not only cationic GSH S-transferases but also anionic GSH S-transferases have the binding capacity to the antibiotics, and that the extent of binding of the antibiotics to anionic GSH S-transferases is similar to the one to cationic GSH S-transferases. Therefore, anionic GSH S-transferases are supposed to play nearly the same role as cationic GSH S-transferases in transport of the antibiotics in human liver. The fact that the extent of binding of the antibiotics to human liver GSH S-transferases is closely correlated with the extent of biliary excretion of the antibiotics suggests that human liver GSH S-transferases play an important role in the transport of certain antibiotics from plasma, through hepatocytes, into bile.

Anions↗