PubMed Health⌕ Search

Biomedical subjects

Y Nishijima

Publications and source records attributed to Y Nishijima.

At least 73 records · Page 4Linked to original sources
PubMed1987

Fluorescence of the tryptophyl residues of the constant fragment of the immunoglobulin light chain.

The constant (CL) domain of the type-lambda immunoglobulin light chain contains two tryptophyl residues. The fluorescence lifetimes of the CL fragment and its two modified forms, the reduced CL, and reduced and alkylated CL fragments, were measured at pH 7.5 and 25 degrees C. The fluorescence decay kinetics of these fragments were described in terms of two lifetimes. The static and dynamic quenching reactions by acrylamide of the tryptophyl residues of these fragments were measured and their dynamic properties were compared with the static properties reported previously (Goto, Y. & Hamaguchi, K. (1979) J. Biochem. 86, 1433-1441; Goto, Y. & Hamaguchi, K. (1986) Biochemistry 25, 2821-2828; Ashikari, Y., Arata, Y., & Hamaguchi, K. (1985) J. Biochem. 97, 517-528). It was found that although the static conformation of the reduced CL fragment is very similar to that of the intact CL fragment, the dynamic conformations of these two fragments differ considerably.

Acrylamides↗
PubMed1984

[Variations in spinal cord blood flow in stepwise spinal cord impaction injury].

Referring to the experimental study on acute spinal cord injury, it is known that gray matter falls into an ischemia after injury, but opinions have not been unanimous whether or not the white matter falls into ischemia or hyperemia. The blood flow through the white matter varies according to the severity of the injury and degree of resultant paraplegia. Using rabbits, the authors carried out a series of experimental acute spinal cord impaction injury giving impactions at different strength stepwise, i.e., 400, 300, 200 and 100 gcf (g X cm X force) respectively at the 9th thoracic level of the spinal cord. Thus, upon observation of the paralysed levels and measurement of variable spinal cord blood flows according to the hydrogen clearance method, it was concluded as follows: In the 400 and 300 gcf impaction groups a complete paraplegia was observed with a decrease of spinal cord blood flow both in the gray and white matters. In the 200 gcf group mainly incomplete paraplegia was occurred, and while gray matter showed ischemia, white matter showed indefinite response consisting of both ischemia and hyperemia. In the 100 gcf impaction group the gray matter fell into ischemia, but white matter showed a biphasic increase of blood flow. From the above results it was noted that upon impaction causing complete paraplegia spinal white matter shows ischemia and upon impaction giving transient paraplegia blood flow increases. Ischemia thus does not appear to be a common behavior of spinal cord blood flow spinal cord injury.

Animals↗
PubMed1982

[Studies of blood flow through the spinal cord of rabbit using the H2 clearance method ].

Using the H2 clearance method, spinal cord blood flow of the rabbit could be steadily measured. This allowed examination of blood flow problems using data analysis to provide informed decisions as to whether or not the blood flow through the gray and white matter was distinguishable. Spinal cord blood flow was also compared through the cervical, thoracic, and lumbar cord regions. The results were as follows: 1. The H2 clearance curves consisted of about 70% monoexponential curve (Mono), and 30% biexponenial curve (Bi), with a tendency toward higher values in the latter. 2. In Bi, a significant positive correlation was noted between the total flow values and the initial slope method values. The initial slope method was therefore used for subsequent data analysis. 3. By using a histogram to evaluate the data on each medullary segment, it was possible to separate a subgroup with a peak around 20 ml/100 g/min and another one with a peak around 40 ml/100 g/min. Based on the microangiographic findings, a more abundant vascular distribution was demonstrated in the gray matter than in the white matter. The first subgroup was noted corresponding to the blood flow through the white matter, and the latter through the gray matter. When the blood flow through the white and gray matter was calculated according to the subgroup data base, the flow ratio through the white and gray matter was 1:2. 4. Comparing the blood flow through each spinal cord segment revealed no significant difference at a p level of 0.01.

Animals↗
PubMed1980

2'-Deoxy-2'-azidoadenosine triphosphate and 2'-deoxy-2'-fluoroadenosine triphosphate as substrates and inhibitors for Escherichia coli DNA-dependent RNA polymerase.

The effects of 2'-substitutions of ATP on the substrate and inhibitor properties for RNA synthesis were studied in the poly(dAT)-dependent reaction of Escherichia coli RNA polymerase. In the presence of UTP, 2'-deoxy-2'-azidoadenosine 5'-triphosphate (AZTP) was incorporated into an acid-insoluble fraction at one-tenth of the rate of ATP incorporation; it thus acts as a competitive inhibitor for poly(AU) synthesis. On the other hand, another ATP analog, 2'-deoxy-2'-fluoroadenosine 5'-triphosphate (AfTP), was co-polymerized with UTP into acid-insoluble materials at a rate less than 1% of that of ATP incorporation; in addition, it exerted a strong but mixed-type inhibition on poly(AU) synthesis. Different modes of action of the two ATP analogs are discussed in connection with the specificity of substrate recognition by RNA polymerase.

DNA-Directed RNA Polymerases↗
PubMed1979

Determination of free glycerol on human skin surface.

In water soluble substances obtained by water extraction from human skin surface, free glycerol was detected by gas chromatography mass spectrometry. A selected ion monitoring method was employed to measure low concentration of free glycerol and the mean amounts were found to be about 0.7 microgram cm-2 on the cheek and 0.2 microgram cm-2 on the forearm and sole.

Chromatography, Gas↗
PubMed1978

[Postmortem examination of patients with non-surgically treated ruptured aneurysms (author's transl)].

The is no doubt that radical surgery has been successful in preserving the lives of patients with ruptured aneurysms. On the other hand, no matter how successful we have been we cannot and must not forget the patients who died without undergoing surgery. Therefore, we investigated from clinical course, laboratory work, including angiography and autopsy, 38 cases who died during hospitalization in order to elucidate the causes of death in the natural course and to find the possibilities of minnimizing the number of non-operative fatalies. We classified the causes of death into 3 groups: intracranial hemmatomas, brain ischemia due to vasospasm, and aggravation of the general condition. From the study, it was concluded that most of the lives could have been saved, if appropriate diagnosis and treatment had been made as soon as possible after the initial hemorrhage.

Adult↗
PubMed1978

[Chemotherapy of peritonitis with particular reference to concentrations of sulbenicillin in human ascites (author's transl)].

Twenty-seven patients with peritonitis to whom a drain was applied were given sulbenicillin (SBPC), a broad-spectrum antibiotic, which has so little hepatic and renal toxicity that massive doses may be feasible, and examination was made as to its therapeutic effects and concentrations of the antibiotic in the ascites. Daily dosage of SBPC was 10g in two divided doses in most cases given by the intravenous infusion. Medication was continued for 3 approximately 15 days. The highest daily dosage was 20g and the largest total dosage reached 190g, but there was no adverse reaction except for one case of a slight anemia. Peritonitis complicated appendicitis, adnexitis, duodenal ulcer perforation, intestinal obstruction or trauma as its primary disease. No difference in the therapeutic effect existed among the primary diseases. The response to SBPC treatment was excellent in 8 of the 27 patients and good in 17. Two patients failed to respond to the therapy. When SBPC was given just before operation, the SBPC concentration in ascites obtained at operation was 112 microgram/ml in 2 cases. The SBPC concentrations in ascites were examined following intravenous infusion of 5g over an hour, and a peak concentration of 94.7 microgram/ml was obtained at the completion of infusion (an hour after the start of infusion), which gradually decreased thereafter. In the ascites excreted from the drain after operation, a high concentration of 12.7 approximately 90.2 microgram/ml (mean: 51.7 +/- 7.7 microgram/ml) was obtained on the day after the operation day, but the concentration was lower thereafter. The SBPC concentrations in ascites were compared as regards the sites of drainage (Winslow's foramen, ileocecum and Douglas' fold), but no particular difference was observed. The SBPC concentrations in ascites after operation were in inverse proportion to the alleviation of peritonitis. They were higher when the inflammation was severer.

Adolescent↗
PubMed1975

Effect of fentanyl, a narcotic analgesic, on two components of the jaw opening reflex.

An action of fentanyl, a short-acting narcotic, on the reflex discharge in the digastric nerve induced by the inferior alveolar nerve stimulation was investigated in alpha-chloralose anesthetized cats. In the ipsilateral digastric reflex discharge, there were an early phase induced by stimulus exciting Aalpha fibers and a late phase appearing when Adelta fibers were also stimulated. Following dorso-lateral cordotomy at the obex level, an isolation of the spinal trigeminal nucleus caudalis, a total area in the digastric reflex discharge decreased, while its first peak amplitude was little affected, indicating a disappearance of the late phase and a preservation of the early phase. Fentanyl depressed both the total discharge area and the first peak amplitude. After dorso-lateral cordotomy, the depression of the area decreased considerably, whereas that of the amplitude decreased slightly. Results indicate that fentanyl depressed both the early phase which is activated by the Aalpha fiber stimulation, not via the subnucleus caudalis and the late phase which is activated by the Adelta fiber stimulation via the sub-nucleus caudalis or its surroundings. The latter action would be related to the analgesic action of fentanyl.

Animals↗
PubMed1975

Unit activity in somatosensory area II (SII) and tooth pulp stimulation in a cat.

Within and near the rostral half of the anterior ectosylvian gyrus of an unanesthetized chronic cat, properties of units which responded to stimulation of the ipsilateral upper canine tooth pulp were studied. In total 75 responsive units were recorded by 192 microelectrode penetrations. Discharge patterns of these units to pulp stimulation were classified into 3 types: single spike response (4 units), short burst response (66 units) and prolonged response continuing up to several hundred msec (4 units). Spontaneous activities of one exceptional unit were depressed for 200-300 msec after pulp stimulation. These units were scattered in the explored cortical area, indicating that the SII somatotopically organized area may also receive nociceptive inputs. Most of these units responded to some modalities of mechanical stimuli applied to various parts of the body surface including face and head. This result suggests that they may correspond to the neurons unspecific with regard to modality and place observed in the anesthetized cat. Few units activated by pulp stimulation were encountered in the rostral portion of the anterior ectosylvian gyrus, where MELZACK and HAUGEN (1957) recorded the evoked potential by pulp stimulation. Five tooth pulp-sensitive units which were excited only by pin pricks and/or firm pressure were encountered on the dorsal bank of the anterior ectosylvian sulcus, the non-somatotopically organized area of SII.

Animals↗