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Biomedical subjects

S Y Lin

Publications and source records attributed to S Y Lin.

At least 181 records · Page 10Linked to original sources
PubMed1996

[Effect of microinjection of angiotensin II into area postrema on renal sodium excretion].

It has been known that area postrema (AP) possesses angiotensin II (A II) receptors and senses directly the change of blood A II level. The effect of microinjection of A II into the AP on renal sodium excretion was studied in the present investigation. Our experimental results show that microinjection of A II (2, 20 ng) increases GFR, RPF and UNaV (P < 0.05). These changes can be abolished by A II antagonist, saralatin and renal denervation (P < 0.05). However microinjection of A II (20 ng) into NTS produces no such changes. These results strongly suggest that the A II induced changes of renal hemodynamics and urine sodium excretion are mediated through AP.

Angiotensin II↗
PubMed1996

[Effects of subtotal nephrectomy and high salt intake on atrial natriuretic peptide in the brains of rats].

In order to explore the role of brain atrial natriuretic peptide (ANP) in regulating water and electrolytes, the changes of the ANP content of various brain areas in the status of high salt intake and in 3/4 nephrectomy rats. In control group, a wide distribution of ANP was observed in different areas of the brain. The amount of daily water intake and urine were larger, and urine sodium concentration was lower in the 3/4 nephrectomy group than those in the control group (P < 0.05). In the ten nuclei we have studied, ANP content was not significantly different from that of the control (P > 0.05). In the high salt group, water intake, urine volume and urine sodium concentration were significantly higher than those in the control. In this group, brain ANP increased in the periventricular nuclues (PVN) and arcute nucleus (Arc) (P < 0.05). The results indicate that ANP in anteroventral region of the third ventricle (AV3V) might play important role in the regulation of water and electolytes.

Animals↗
PubMed1995

Sequence variation in the capsid protein genes of human papillomavirus type 16 and type 31.

The sequences of the capsid genes of a human papillomavirus type 16 (HPV 16) DNA and an HPV 31 DNA were determined. The HPV 16 DNA contained genes coding for the most variable HPV 16 capsid proteins yet identified (17 variable amino acids). Three of six coding changes in the HPV 31 DNA occurred at positions equivalent to ones where variable amino acids in HPV 16 have been observed. Variable amino acids in both viruses occurred predominantly in regions which showed amino acid variation when closely related types of HPV were compared; thus, most of the factors which determined the intratypic variation in the capsid proteins of the viruses described here were likely the same as those which determined differences between the capsid proteins of different HPV types.

Base Sequence↗
PubMed1995

Effect of diabetic duration on the secondary structures of the human lens capsules in diabetic cataracts.

The decrease in triple helix content from 16% to 9% and in beta-turn content from 45% to 33%, combined with markedly increased random coil structure (16%) can be found in the secondary structure contents of lens capsule of the premature cataractous patients with longer diabetic history. However, almost the same peak position and secondary structure content are observed in the curve-fitted IR amide I band of lens capsules of both non-diabetic controls and premature cataractous patients with shorter diabetic history, even if the cataracts are senile. The present study emphasizes the duration of diabetes as a major cause to alter the secondary conformation of the cataractous human lens capsules in diabetic patients.

Adult↗
PubMed1995

Non-destructive analysis of the protein conformational structure of human pituitary adenomas using reflectance FT-IR microspectroscopy.

Reflectance Fourier-transform infrared microspectroscopy was used to determine the secondary structure and composition of the different human pituitary adenomas. Non-functioning pituitary adenomas exhibited similar protein secondary structure and conformational composition, but active pituitary adenomas revealed different behavior. The differences in secondary structure for the different human pituitary adenomas might possibly be due to the different protein conformations of the proliferated adenoma tissues and various hormones shared.

Adenoma↗
PubMed1995

Preparation and evaluation of sodium diclofenac controlled-release tablets. II. Dibasic calcium phosphate as a retardant in mixtures for direct compression.

The dissolution behaviour of a direct compression compact prepared with sodium diclofenac and dibasic calcium phosphate (DCP) in different weight ratios with or without Biosoluble polymer (acrylic-based resin) was investigated in distilled water and in a medium with changing pH. The results indicate that the amount of sodium diclofenac released from the compact was dependent on the amount of drug and DCP used in the compact, and was also controlled by the amount of Biosoluble polymer added. A chemical reaction forming diclofenac acid might occur on the surface of the sodium diclofenac compact during exposure to the acidic medium, which was confirmed by diffuse-reflectance spectroscopy. The tablet with a 1:2 weight ratio of sodium diclofenac to DCP exhibited a sustained-release behaviour, similar to commercial sustained-release products (Voltaren SR-100 and Grofenac Retard), but a lower release rate was found as compared to the commercial products. The dissolution behaviour of the study tablet and the commercial products was found to be dependent on the dissolution medium and the rotating speeds. Glass beads were added to the dissolution assembly to simulate the influence of food, and the enhanced friction between tablet and glass beads might result in a higher dissolution rate of the tablet and the commercial products.

Acrylates↗
PubMed1995

Phylogenetic relationships among two species of golden monkey and three species of leaf monkey inferred from rDNA variation.

Restriction maps of rDNA repeats of five species of Colobinae and three outgroup taxa, Hylobates leucogenys, Macaca mulatta, and Macaca irus, were constructed using 15 restriction endonucleases and cloned 18S and 28S rRNA gene probes. The site variation between Rhinopithecus roxellana and Rhinopithecus bieti is comparable to that between Presbytis françoisi and Preshytis phayrei, implying that R. bieti is a valid species rather than a subspecies of R. roxellana. Phylogenetic analysis on the 47 informative sites supports the case for Rhinopithecus being an independent genus and closely related to Presbytis. Furthermore, branch lengths of the tree seem to support the hypothesis that the leaf monkeys share some ancestral traits as well as some automorphic characters.

Animals↗
PubMed1995

Congenital tracheal cartilaginous sleeve.

The congenital tracheal cartilaginous sleeve (TCS) results from a vertical fusion of the tracheal cartilages. This rare malformation is usually associated with one of the craniosynostosis syndromes, such as Crouzon's disease, Pfeiffer's syndrome, or Goldenhar's syndrome. Three new cases of TCS are reported, two with autopsy findings including the histopathology of horizontal tracheal sections. Salient features of the clinical presentation, diagnostic evaluation, endoscopic findings, histopathology, treatment, and prognosis for TCS are summarized from the perspective of the otolaryngologist. In addition, the literature is reviewed, and previously reported cases are discussed. Although infants with TCS often have multiple abnormalities, this tracheal malformation is not incompatible with life. Since multiple lesions of the larynx and trachea may be present, endoscopic evaluation is recommended for infants with TCS who experience airway distress. A smooth trachea lacking the normal ridges of tracheal arches suggests the diagnosis of TCS. With early recognition and appropriate management (including tracheotomy, if necessary, and aggressive management of pulmonary hygiene), patients may survive into childhood.

Cartilage↗
PubMed1995

Effect of ethanol on the protein secondary structure of the human gastric mucosa, in vitro.

The effect of ethanol on the secondary conformational structure of proteins of the human gastric mucosa was investigated by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) spectroscopy. The IR peak intensity and position of each structural component of gastric mucosa was found to change significantly with the ethanol concentration and length of exposure. The peak intensity due to the beta-sheet and/or beta-turn conformational structure in amide I and II bands of gastric mucosa clearly increased after treatment with ethanol. Moreover, the peak at 1635 cm-1 shifted to 1630 cm-1 after treatment with 40% ethanol for 3 h, or 80% ethanol for 1 h, and a distinct shoulder also appeared at 1643 cm-1. This shift occurred more rapidly and was more pronounced after exposure of mucosa to 80% ethanol, compared with the effect of 40% ethanol, but the alpha-helical structure at the amide I and II bands was not influenced by either concentration of ethanol. Ethanol treatment might also transform the secondary structure of amide III in gastric mucosa from an alpha-helix to a mainly random coil with extensive unfolding. The absorption between 1180 and 980 cm-1, which is assigned to glycoprotein structure, was also reduced after treatment with ethanol. This strongly indicates that ethanol influences the conformation of the lipids and proteins of human gastric mucosa, leading to their deformation.

Ethanol↗
PubMed1995

Secondary conformational structure of type IV collagen in different conditions determined by Fourier-transform infrared microscopic spectroscopy.

The IR spectra of Type IV collagen in a crystalline state, in a solid film and in aqueous solution were investigated by FT-IR microscopic spectroscopy using either the transmission method or attenuated total reflection method. The effect of compression pressure on the secondary structure of Type IV collagen in different states was also studied. The results indicate that amide I, containing triple helix (1636 cm-1), alpha-helix (1655 cm-1) and random coil (1666 cm-1) peaks, for Type IV collagen in crystalline state had almost the same IR spectral position as that in solid film but the peak areas of amide I, II, III and the proteoglycan region was larger for Type IV collagen in solid film. The IR spectrum of amide I (alpha-helix: 1647 cm-1, triple helix: 1633 cm-1) for Type IV collagen in aqueous solution was different from that in the crystalline state or solid film. The random coil structure existed predominantly in the dry state of collagen. After compression pressure was applied to the crystal of type IV collagen, its IR spectrum transformed significantly. The peak area of amide I was clearly enlarged but the peak area of amide II decreased sharply. When the compression was applied to the solid film, its IR spectral position did not change but both peak areas of amide I and II decreased significantly although the peak area in amide III and the proteoglycan region were almost the same. We also found that two new additional peaks at 1054 and 1023 cm-1 appeared in the proteoglycan region for both of the above compressed samples. Pressure seemed to significantly influence the amide I, II and proteoglycan region, leading to the deformation of collagen.

Collagen↗
PubMed1995

Drug-induced liver disease--a review of 14 cases.

The clinical and pathological features of 14 cases of acute drug-induced liver disease (DILD) were analyzed using the French group method for drug reaction assessment. Among them, 8 were of the cytotoxic type, 4 were of the cholestatic type and 2 were of the mixed type. Serum alkaline phosphatase (ALP) levels of the cytotoxic type DILD were all < 1.8 times the normal value, while those of the cholestatic type DILD > 1.8 times (P < 0.05). The alanine aminotransaminase and aspartate aminotransaminase (ALT and AST) levels of the cholestatic type were all < 13.1 times the normal value, while those of the cytotoxic type varied from 2.2 to 118 times the normal value. We found that steatosis was the major feature in the cytotoxic type with ALT and AST < 2.5 times the normal value. Piecemeal necrosis was noted only in all the cases with ALT and AST > 20 times the normal value. In the cholestatic type, the pathological features of the oral contraceptive-related DILD showed mainly cholestasis, whereas chlorpromazine-related DILD revealed additional portal inflammation. Meticulous taking of patient history and clinical assessment are mandatory for the diagnosis of DILD. The ALP levels were helpful in distinguishing different types of DILD. There are some correlations between biochemical changes and pathological features, and both are helpful in distinguishing different etiologies of DILD when the inciting drug is in doubt.

Adult↗
PubMed1995

Priming reversal of profound atracurium blockade by edrophonium and neostigmine.

Accelerated reversal of moderate neuromuscular blockade has been reported to be effective by giving anticholinesterase in divided doses (priming reversal). To evaluate its effectiveness in profound blockade, forty ASA physical status I or II patients were studied. After receiving 0.5mg/kg of atracurium during N2O-O2-halothane anesthesia, they were reversed at 5% spontaneous recovery of first twitch height (T1) measured by train-of-four (TOF) stimulation. Edrophonium 1mg/kg was administered intravenously either in a single bolus dose (Group I, n = 10) or in an initial priming dose of 0.2mg/kg followed one minute later by 0.8mg/kg (Group II, n = 10). Neostigmine 0.05mg/kg was administered in a single bolus dose (Group III, n = 10) or in divided priming dose of 0.01 mg/kg followed one minute later by 0.04mg/kg (Group IV, n = 10). The recovery time from the first injection of the reversal agents until the TOF ratio reached 75% was significantly longer (p < 0.05) in Group III (681.5 +/- 77.5 sec) compared to Groups I, II, and IV (451.3 +/- 72.3 sec, 470.6 +/- 39.8 sec, and 448.1 +/- 42.5 sec, respectively; no statistical difference among these three groups). It is concluded that priming reversal by neostigmine, but not edrophonium, produced a significantly faster recovery of profound atracurium blockade. Using the priming method, neostigmine may reach a similar recovery time as edrophonium in profound blockade under equipotent doses.

Adult↗
PubMed1995

Direct or indirect skin lipid-ordering effect of pyrrolidone carboxylate sodium after topical treatment with penetration enhancers.

The structural changes in the lipid of the excised skin of nude mice and the porcine stratum corneum was investigated by in vitro treatment with vitamin C, oleic acid, or DMSO. The CH2 stretching vibrational peaks of lipid near 2920 cm-1 (asymmetric) and 2850 cm-1 (symmetric) shifted to higher wavenumber due to the lipid-disorder after in vitro treatment with above enhancers. The spectral shift of the asymmetric CH2 band was more sensitive than that of the symmetric CH2 band. The higher wavenumber of CH2 stretching bands decreased gradually to the lower region after co-treatment or posttreatment with pyrrolidone carboxylate sodium (PCA Na). Such a decrease was dependent on the PCA Na concentration and the time of treatment. The higher the concentration of PCA Na used, the lower value of the permeability coefficient of vitamin C through the excised skin and the downward spectral shift of asymmetric CH2 band were obtained. When PCA Na coexisted with vitamin C in the cell donor compartment, a competitive effect between PCA Na and vitamin C was found. The oleic acid was supposed to directly insert it into the lipid structure to form a rigid structure, leading to larger spectral shift of both stretching bands but lesser restoring ability after PCA Na treatment. However, DMSO only displaces water from the lipid head groups and protein domain of skin to indirectly loosen the lipid structure, resulting in lesser spectral shift of the CH2 stretching bands to higher region, which was easier and better restoration after PCA Na application. The PCA Na enabled to restore the disordered lipid structure to order state might be attributed to PCA Na previously penetrated into skin and then absorbed water to directly or indirectly rearrange the disordered lipid bilayer structure.

Absorption↗
PubMed1995

An urgent technique of applying high frequency jet ventilation in patients with extreme periglottic stenosis.

Applying high frequency jet ventilation (HFJV) to patients with extreme periglottic stenosis (EPS) carries high risk of barotrauma or severe circulatory depression, since the stenotic airway will result in inadequate outflow tract obstructing the passage of the expired gas. We encountered with emergent obstruction of the outflow tract in 13 patients with EPS during HFJV in endolaryngeal microsurgery (ELM) procedures. The phenomenon of progressive gas trapping occurred within seconds in all patients. Barotrauma and disastrous circulatory depression would occur if we had not recognized them and then taken some measures immediately. We surmounted these potentially lethal events without interrupting the surgical procedures and found neither hypoxia nor barotrauma in all these patients. This may attribute to an urgent technique, i.e., intermittent disconnecting the jet conduit at the junction of the proximal end of the insufflation catheter and the distal end of the patient connecting tube of jet ventilator during HFJV.

Adult↗
PubMed1995

Arthroscopic debridement for osteoarthritis of the knee: a seven years follow-up study.

We reviewed 32 knees with osteoarthritis of the knee treated by either arthroscopic debridement in association with drilling the subchondral bone or arthroscopic debridement alone and followed for 2.5 to 11 years. Eighteen knees had arthroscopic debridement and drilling the subchondral bone, and 14 knees had arthroscopic debridement alone. In the group treated with arthroscopic debridement and drilling the subchondral bone, 55.6% had good to excellent results, 22.2% had fair results, and 22.2% had poor results. In the group that had arthroscopic debridement alone, 57.2% had good to excellent results, 35.7% had fair results, and 7.1% had poor results. There was better relief of pain in the group with arthroscopic debridement alone.

Adult↗
PubMed1995

[Effects of Shenmai injection on immune function in stomach cancer patients after chemotherapy].

Sixty-three cases with stomach cancer were randomized and observed, the results showed that the count of T lymphocytes in chemotherapy combined with Shenmai injection (SMI) group increased, while in control group it decreased, the difference was significant (P < 0.05). The results also indicated that the count of OKT4 cells and the ratio of OKT4/OKT8 decreased after chemotherapy, but in SMI group both parameters increased in advence which were higher in the 4th week after chemotherapy than that before chemotherapy. However, the count of OKT1 cells and the ratio of OKT4/OKT8 were still in low level. Serum interleukin-2 receptor (sIL-2R) level also decreased (P < 0.05), while activities of natural killer cell (NK) and lymphokine activated killer cell (LAK) level increased (P < 0.05) in SMI group. Although the sIL-2R level had no change, both NK and LAK level decreased in control group. In addition, the difference of IgA, IgM, IgG level were not significant between these two groups. This suggested that SMI might improve human immune function to facilitate the chemotherapy of patients with stomach cancer.

Adenocarcinoma↗
PubMed1995

Comparison of antihypertensive effects of nicardipine with nitroglycerin for perioperative hypertension.

BACKGROUND: To compare the efficacy of intravenous (iv) nicardipine with nitroglycerin for the treatment for patients with perioperative hypertension. METHODS: Forty patients with perioperative hypertension randomly divided into two groups were treated with intravenous calcium entry blocker, nicardipine, or vasodilator, nitroglycerin. Haemodynamic measurements including mean arterial and pulmonary arterial pressure, central venous and pulmonary capillary wedge pressure, and cardiac output were recorded; peripheral and pulmonary vascular resistance were calculated. RESULTS: Both medications were effective in reducing blood pressure and controlling haemodynamics. During the maintenance by continuous iv infusion, nicardipine controlled hypertension more rapidly than nitroglycerin (nicardipine 10.5 +/- 2.5 min and nitroglycerin 18.7 +/- 2.8 min, p < 0.05) without significant alteration in heart rate. The total frequency of dose adjustments required to achieve therapeutic response was significantly less in the nicardipine-treated group (2.5 +/- 0.3 for nicardipine and 6.2 +/- 1.4 for nitroglycerin, p < 0.05). Incidence of hypotensive episodes during the infusion were observed in both groups [nicardipine 5% (1/20) and nitroglycerin 30% (6/20), p < 0.05]. CONCLUSIONS: Intravenous nicardipine is as effective as nitroglycerin in the treatment of perioperative hypertension. Specific advantages have been identified such as stable dose-response effect, less hypotensive and tachycardial effects during the use of iv nicardipine in treatment of hypertensive patients.

Aged↗