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Biomedical subjects

K Kaya

Publications and source records attributed to K Kaya.

At least 37 records · Page 2Linked to original sources
PubMed1997

Pulmonary microvascular injury following general anaesthesia with volatile anaesthetics--halothane and isoflurane: a comparative clinical and experimental study.

Pulmonary microvascular injury has become a recently studied phenomenon that may be responsible for most of the complications associated with the lungs. Thirty patients undergoing partial hemilaminectomy or discectomy due to hernia of nucleus pulposus underwent Tc-99m HMPAO lung clearance as well as Tc-99m pertechnetate lung scintigraphy pre-operatively, and following general anaesthesia with halothane and isoflurane (third, fourth and tenth post-operative days). The results were compared with conventional techniques and haemodynamic parameters during the peri-operative period. In order to demonstrate acute phase changes under general anaesthesia and to perform pathological examinations, 21 New Zealand rabbits underwent radionuclide studies with Tc-99m HMPAO or Tc-99m pertechnetate. Lung biopsies were also performed. Despite no significant differences in any of the conventional diagnostic techniques, Tc-99m pertechnetate lung scintigraphy was performed for both the halothane and isoflurane groups, and Tc-99m HMPAO lung clearance was performed for the isoflurane group pre- or post-operatively. Tc-99m HMPAO lung clearance was impaired significantly in the halothane group on the third post-operative day (half time: 6.4 +/- 1.6 pre-operative and 13.76 +/- 3.3 s, P < 0.001) decreasing to pre-operative levels on the tenth post-operative day. Acute phase exposure to halothane was characterized with extremely abnormal Tc-99m HMPAO lung clearance in rabbits with respect to isoflurane, diminishing to control levels on the third day (half time: 8.7 +/- 86 control and 28.65 +/- 4.6, P < 0.001). Pathological examinations also demonstrated endothelial damage on acute exposure in the halothane group. General anaesthesia with halothane may give rise to alveolar microvascular injury, which generally seems to be underdiagnosed and may lead to serious post-operative complications.

Adult↗
PubMed1995

Astasin, a novel cytotoxic carbohydrate-conjugated ergosterol from the colorless euglenoid, Astasia longa.

A novel cytotoxic carbohydrate-conjugated ergosterol (astasin) was found in cells of the colorless euglenoid, Astasia longa. Astasin accounted for about 2.4% of the total lipid of the cells. FAB-MS spectra of astasin showed MH+, 583.3387 (M+, C35H50O7). Astasin was composed of ergosterol (1 eq.), alpha-D-xylopyranose (1 eq.), and oxalic acid (1 eq.). By the acetylation using acetic anhydride and pyridine, oxalic acid was removed from astasin, and three hydroxyl groups of the xylopyranose moiety were acetylated. The two dimensional 13C- and 1H-NMR spectra suggest the oxalic acid was esterified with hydroxyl groups at C-2 and C-3 of the xylopyranose moiety and the hydroxyl group at C-1 of the xylopyranose was glycosidically linked to the hydroxyl group at C-3' of the ergosterol moiety. From the results, the structure of astasin was identified as 2,3-oxalyl-alpha-D-xylopyranosyl (1 --> 3')ergosterol. When cells of HL 60, a human lymphoma, were cultured with astasin, 50% of the cell growth was inhibited at 5.0 micrograms astasin/ml medium, and the cell growth was inhibited completely and 50% of the initial cells was killed at 10.0 micrograms astasin/ml medium.

Animals↗
PubMed1993

Thioic O-acid ester in sulfolipid isolated from freshwater picoplankton cyanobacterium, Synechococcus sp.

A thioic O-acid ester-containing sulfolipid (thionsulfolipid) was isolated from cells of picoplankton cyanobacterium, Synechococcus sp. The lipid accounted for about 0.2% of the lyophilized cells. The lipid was subjected to mild alkaline hydrolysis, and the structures of the hydrolysis products were identified by infrared spectra, mass and nuclear magnetic resonance spectrometries, as fatty acids and hexadecane-, hexadecene- and tetradecanethioic S-acids. Thioic S-acid was further confirmed by the synthesis of hexadecanethioic S-acid from palmitoylchloride and hydrogen sulfide. The positional distribution of the thioic acid ester in the lipid was determined by beta-galactosidase, sulphur-oxygen exchange reaction using silver nitrate, and lipase hydrolysis of the diacylglycerol derived from the lipid. The structure of the thionsulfolipid was identified as 6-sulfo-alpha-D-quinovopyranosyl(1-->1')-2'-O-acyl-3'-O-thioacy l -2-glycerol. When cells of HL 60, as a human lymphoma, were cultured with thionsulfolipid, 61% of the cell growth was inhibited at the concentration of 200 micrograms/ml. The lipid was toxic against minnows (Tanichtys albonubes). The LD50 was 20 ppm. Thioic O-acid ester-containing lipid (thionsulfolipid) has not been found in any other photosynthetic organisms.

Cyanobacteria↗
PubMed1993

Quail spleen is enlarged by microcystin RR as a blue-green algal hepatotoxin.

Toxic effects of microcystin RR as a blue-green algal hepatotoxin in laboratory quails were examined. In order to determine the microcystin RR LD50, purified microcystin RR was injected into the peritoneum of the quails. The value obtained was 256 micrograms/kg quail. Usually the quails died between 14 and 18 hr after the injection. After administration of the toxin, the quail spleens were enlarged to a doubling of the control spleens, whereas the lives did not change. These effects are quite different from those in mice and rats, indicating the toxic mechanism of the toxin in quails is different.

Animals↗
PubMed1993

Intraoperative measurement of saphenous vein bypass graft flow with transesophageal echocardiography.

The value of transesophageal echocardiography (TEE) for detecting saphenous vein coronary graft (SVG) flow was investigated. Thirty-five consecutive patients undergoing elective coronary artery bypass grafting (CABG) were studied intraoperatively. SVG flow characteristics obtained by TEE were compared with those gathered by an electromagnetic flowmeter (EMF). A total of 59 patent bypass grafts were examined. Pulsed-wave Doppler signals could be detected in 38/59 of the grafts studied (64.4%). The detection rate was the same for all types of grafts encountered (left anterior descending, right coronary, left circumflex, and lateral ventricular branches). The flow profiles obtained by TEE were very similar to those detected by EMF. Both profiles showed a bifid appearance with maximal flow in late diastole. The peak velocity seen in a SVG during diastole was 39.0 +/- 12.7 cm/sec. Graft volume determined by TEE correlated well with data obtained by EMF (r = 0.84). TEE is an attractive technique for noninvasively detecting phasic flow in SVGs; however, the flow detection rate is too low for the routine evaluation of graft patency.

Adult↗
PubMed1993

Perineural pethidine: effects of different doses on nerve conduction.

Forty healthy young volunteers were divided randomly into four equal groups. 2 ml of solutions of pethidine (meperidine) in concentrations of 0.5%, 1% and 1.5% were given to three groups of 10 subjects: a fourth group received saline. Sensory evoked responses obtained via surface electrodes from both sural nerves simultaneously in the pethidine groups and unilaterally in the control group, were evaluated for latency, conduction velocity and amplitude. Sensory changes at the innervation zone were monitored by means of a pinprick. All recordings were obtained prior to injection and at 5 min intervals for 30 min. Concentrations of 1% and 1.5% pethidine were associated with significantly lower amplitudes and with hypoalgesia. Other parameters did not change.

Adjuvants, Anesthesia↗
PubMed1992

A novel disialoganglioside in rat spleen lymphocytes.

A novel ganglioside has been identified as the predominant disialoganglioside of the lymphocytes prepared from rat spleen. The ganglioside was isolated from rat spleen and characterized by compositional analysis, methylation analysis, sialidase hydrolysis, proton NMR spectroscopy, and negative ion fast atom bombardment mass spectrometry. The structure was determined as follows. [formula: see text] This ganglioside is a unique derivative of N-acetyllactosaminyl-GM1. The three monosialogangliosides containing N-acetyllactosaminyl-GM1 structure, which had been originally isolated from rat spleen (Nohara, K., Suzuki, M., Inagaki, F., Ito, H., and Kaya, K. (1990) J. Biol. Chem. 265, 14335-14339), were also found in the lymphocytes and were hardly detected in the spleen remnant tissue depleted of single cells. On the other hand, GD1c(NeuGc,NeuGc) (IV3(NeuGc alpha 2-8NeuGc)-Gg4Cer), the overwhelmingly predominant ganglioside of rat thymocytes (Nohara, K., Suzuki, M., Inagaki, F., and Kaya, K. (1991) J. Biochem. (Tokyo) 110, 274-278), was demonstrated to be only a minor component of the gangliosides of the spleen lymphocytes. These results suggested that GD1c is characteristic for the immature T lineage lymphoid cells and the gangliosides having lactosaminyl-GM1 structure are specific for other populations of the lymphocytes in rat.

Animals↗
PubMed1992

Tetrahydropyran ring-containing fatty acid-combined taurine (tetrathermoyltaurine) in the taurolipid fraction of Tetrahymena thermophila.

A tetrahydropyran ring-containing fatty acid-combined taurine (tetrathermoyltaurine) was found in the taurolipid fraction of Tetrahymena thermophila. Tetrathermoyltaurine accounted for about 0.6% of the total taurolipid of the cells. The compound was subjected to methanolic hydrochloric acid hydrolysis, and the structures of the hydrolysis products were identified by nuclear magnetic resonance and mass spectrometries, as taurine and 2,3-dihydroxy-9,13-oxy-7-trans-octadecenoic acid (tetrathermic acid). The chemical structure of tetrathermoyltaurine was identified as 2-(2,3-dihydroxy-9,13-oxy-7-trans-octadecenoylamino) ethanesulfonic acid. This structure suggests that tetrathermoyltaurine may be derived from taurolipid B as the major taurolipid of the cells. When cells of HL 60, as a human lymphoma, were cultured with tetrathermoyltaurine, 88% of the cell growth was inhibited at the concentration of 100 micrograms/ml.

Animals↗
PubMed1992

Effects of perineural opioids on nerve conduction of N. suralis in man.

In this study the effects of agonist acting drugs (morphine sulphate, fentanyl citrate and meperidine hydrochloride) on nerve conduction were studied in 43 healthy young volunteers divided into four groups randomly. According to analgesic equivalent doses, the first group received 2 mg morphine sulphate, the second group 0.02 mg fentanyl citrate, the third group 20 mg meperidine hydrochloride, and as control the fourth group received 2 ml of saline. The latencies, amplitudes of the responses and nerve conduction velocities were obtained immediately before and every 5 min after injections up to 30 min. No significant change was observed within or among the morphine sulphate, fentanyl citrate and saline groups whereas in the meperidine hydrochloride group the amplitudes diminished significantly and this finding was still apparent at 30 min. Four of the cases displayed complete blocks. Nerve conduction velocity did not change in the other 6 cases. The significant decrement of the amplitude of the compound nerve action potential in the meperidine hydrochloride group is probably due to local anesthetic-like action of this drug. Morphine sulphate, fentanyl citrate or saline did not show this effect.

Adult↗
PubMed1991

Definition of total biosynthesis pathway of taurolipids in Tetrahymena cells.

Taurine-combined fatty acids were found in the lipotaurine fraction of cells of Tetrahymena thermophila. Taurine and fatty acid moieties of the compounds were identified by nuclear magnetic resonance and gas chromatography-mass spectrometry, respectively. The molar ratio of fatty acid methyl esters and taurine in the hydrolysate of the lipotaurine fraction by methanolic hydrochloric acid hydrolysis, was 1.06:1.00. From the results, the structures of six taurine-combined fatty acids including lipotaurine in the fraction were identified. These structures suggest that the compounds are precursors of lipotaurine as an intermediate of taurolipids biosynthesis, and lipotaurine is biosynthesized via 2-(octadecanoylamino)ethanesulfonic acid and 2-(7-hydroxy-13-octadecenoylamino)ethanesulfonic acid. From the results of the present study and our previous studies, the total biosynthesis pathway of taurolipids is defined.

Animals↗
PubMed1991

Species-specific antibodies of Tetrahymena acid alpha-glucosidase.

1. Tetrahymena acid alpha-glucosidases A and B were purified from T. pyriformis W and T. thermophila 399, respectively. The acid alpha-glucosidases A and B were different in immunological properties and thermostability. 2. The acid alpha-glucosidases A and B reflected specific distribution between T. pyriformis and T. thermophila. 3. Type A and B of taurolipid showed a species-specific distribution pattern between T. pyriformis and T. thermophila.

Animals↗
PubMed1991

A GM1b-derived disialoganglioside GD1c is the predominant ganglioside of rat thymocytes.

The thin-layer chromatographic (TLC) pattern of gangliosides of rat thymocytes showed a profile characterized by the occurrence of a predominant ganglioside which did not correspond to any reference gangliosides of rat brain. The ganglioside was isolated from rat thymus, and characterized by compositional analysis, methylation analysis, sialidase treatment, negative-ion fast atom bombardment (FAB) mass spectrometry, and proton NMR spectroscopy. The structure was elucidated to be NeuGc alpha 2-8NeuGc alpha 2-3Gal beta 1-3GalNac beta 1-4Gal beta 1-4Glc beta 1-1Cer. This is the major ganglioside of rat thymus lymphoid cells and is one of the GM1b-derived gangliosides, GD1c, having two N-glycolylneuraminic acids. This is the first report on the occurrence of GD1c in normal animal cells.

Animals↗
PubMed1991

[Kyotorphin like substance in human cerebrospinal fluid of patients with persistent pain].

Kyotorphin is an analgesic neuropeptide isolated from the bovine brain in 1979. Further studies showed that kyotorphin produces an analgesia through an increased release of met-enkephalin in the brain and the spinal cord. We showed that it is also found in the human cerebrospinal fluid and the concentrations of kyotorphin in normal human CSF is 1.19 +/- 0.51 pmol.ml-1. We also found that it is lower in patients with persistent pain (0.24 +/- 0.04 pmol.ml-1). Above results suggest that kyotorphin acts as a putative neuromediator and/or an endogenous pain modulator in the human brain.

Adult↗