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Biomedical subjects

C Y Lin

Publications and source records attributed to C Y Lin.

At least 325 records · Page 18Linked to original sources
PubMed1991

A bronchial response comparison of exercise and methacholine in asthmatic subjects.

The authors compared the inhaled methacholine and exercise responses in 22 stable unmedicated asthmatic patients. The exercise and methacholine challenges were performed at one to three week intervals. Bronchial responsiveness to methacholine was measured in relation to the concentration of methacholine (PC20M). The response to exercise was expressed as the percentage of fall in FEV1 from the pre-exercise FEV1. The findings showed that 21 of 22 subjects demonstrated a fall in FEV1 of more than 20% after methacholine challenge, while only 9/22 subjects experienced a similar decrease in FEV1. All 9 of these positive response exercise cases completed three consecutive exercise challenges prior to the methacholine challenge. Of these cases, five were refractory to the repeated exercise challenge, and the PD20M at the nonexercise stage was significantly lower than the postexercise state. In fact, the methacholine challenge sensitivity actually decreased (PD20 increased) after repeated exercise. The authors concluded that methacholine seems to be a more sensitive bronchial provocation test than exercise. Second, only 55.6% of the exercise test-positive subjects were refractory to the second exercise challenge. Therefore, other factors besides the release of mediators should be considered in exercise-induced asthma. Third, methacholine sensitivity actually decreased (PD20 increases) after repeat exercise challenge.

Adult↗
PubMed1991

Allergenic components of Aspergillus fumigatus determined by radioimmunoprecipitation.

The allergenic components of Aspergillus fumigatus were identified using radioimmunoprecipitation (RIP) assay. Sera from 20 asthmatic children with positive skin tests to A. fumigatus were used for assay. Immune complexes formed between iodinated A. fumigatus and IgE antibodies in patients' sera were precipitated by immobilized anti-IgE monoclonal antibodies (MAbs). The precipitates were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analyzed by autoradiography. It was found that IgE antibodies in the sera of allergic individuals reacted with several allergenic components of A. fumigatus ranging from 10 to 125 kD. Proteins of 38, 33, and 68 kD were recognized by IgEs from the allergic sera with frequencies of 85%, 65%, and 40%, respectively. It appears that these are the major allergenic components of A. fumigatus.

Allergens↗
PubMed1991

Interactions of adenosine and vecuronium in neuromuscular blockade in cats.

The effect of adenosine on the neuromuscular blockade induced by vecuronium and the capacity of neostigmine to reverse this combined blockade were studied in 30 cats on a standard sciatic nerve--tibialis anterior muscle preparation. Adenosine infused to 6 cats at a constant rate (3.9 +/- 1.1 mg/kg/min) to produce a stable 50% reduction of the mean arterial pressure did not affect neuromuscular transmission. At the same 50% reduction of the mean arterial pressure by adenosine or sodium nitroprusside infusion in another 15 cats, adenosine (n = 9) significantly potentiated vecuronium-induced neuromuscular blockade, but sodium nitroprusside (n = 6) did not. Neostigmine antagonized the neuromuscular blockade of similar degrees produced either by the combination of adenosine with vecuronium in the above 9 cats or by vecuronium alone in the remaining 9 cats. There was no significant difference in the doses of neostigmine given. Because no potentiation was found at the same level of hypotension induced by sodium nitroprusside, the potentiation effect of adenosine on neuromuscular blockade is not likely to be due to the hypotensive effect of adenosine, but may be due to impairment, by adenosine, of acetylcholine release from motor nerve endings. We conclude that adenosine potentiates neuromuscular blockade by vecuronium and that neostigmine can be expected to reverse this combined blockade.

Adenosine↗
PubMed1991

[Effect of succinylcholine on recovery of atracurium-induced neuromuscular blockade].

If muscle relaxation is inadequate at the end of surgery, a transient increase in neuromuscular (NM) blockade should be needed to facilitate closure. Succinylcholine is the only agent of short duration available currently and could be used in the just mentioned circumstance. Therefore, the study was designed to investigate the effects of succinylcholine on the recovery of atracurium-induced NM blockade. Sixty-four female patients who underwent elective surgery under general anesthesia were allocated into 6 groups. Before anesthesia, no patient had received drugs which affect NM transmission. In all patients anesthesia was induced with thiopental, diazepam and fentanyl and maintained with 50% nitrous oxide in oxygen and 0.5-1.5% isoflurane. During anesthesia, blood pressure and electrocardiogram were monitored and end-tidal CO2 was maintained at 30-40 mmHg. Control records of the integrated electromyography responded to train-of-four supramaximal stimulation using a Datex Relaxograph were obtained after induction of anesthesia before a block was produced with an initial dose of succinylcholine 1.0 mg in group I (n = 8) or atracurium 0.4 mg/kg in groups II-VI. On first twitch (T1) recovering to 50% of control, 0.4 mg/kg, 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg and 1.2 mg/kg of succinylcholine were given in groups II (n = 11), III (n = 14), IV (n = 11), V (n = 10), VI (n = 10) respectively. It was seen that succinylcholine 0.4 mg/kg antagonized NM blockade by atracurium but at 0.6 mg/kg, 0.8 mg/kg, 1.0 mg/kg, 1.2 mg/kg it enhanced that.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Clinical features and natural course of HBV-related glomerulopathy in children.

To evaluate the clinical features, immunopathology and the prognosis of hepatitis B virus-associated membranous nephropathy (HBVMN), 34 patients (25 boys and 9 girls) from April 1981 to November 1986 were studied. With Fab fragments of monoclonal antibodies, hepatitis B e antigen (HBeAg) was detected in the glomerular deposits from 30 cases (88.2%) and in the sera from 32 cases (94.1%). These results suggest that HBe Ag plays an important role in the development of HBVMN. In patients without corticosteroid treatment, HBV DNA was found as only episomal molecules with 3.2 kb in macrophage, T and B cells. The HBV cellular DNA disappeared within 12 months. In a HBVMN patient with corticosteroid treatment, even three years later, cellular HBV DNA was still detectable in T cells. They also had occasional proteinuria. From the in vitro study, we also demonstrated that corticosteroid stimulated endogenous HBsAg and HBeAg production from patient's mononuclear cells. Therefore, the use of corticosteroid could lead to a potential risk of enhancing viral replication. In addition, clinical trials of 32 cases demonstrate a relatively poor response to the steroid therapy with persistent heavy proteinuria (32.4%) or a high frequent relapse rate (38.2%); only one case (3.1%) had early response. Four cases received follow-up renal biopsy, progressive sclerosis with interstitial fibrosis being noted in each instance. The stage of membranous nephropathy in light microscope had progressed from stage I or II into III. One had impaired renal function. Therefore, HBVMN does not always take a benign course. Usage of corticosteroid in HBVMN patients should be avoided.

Adrenal Cortex Hormones↗
PubMed1991

Gastric acid secretion in streptozotocin-diabetic female rats.

The secretion of gastric acid in normal and streptozotocin-induced diabetic rats was studied. Female rats were injected with streptozotocin (64 mg/kg BW, iv) or vehicle. Three days later, all rats were fasted overnight before anesthetization with pentobarbital (25 mg/kg BW, ip). The right jugular vein was catheterized. A PE-160 tubing was inserted into the esophagus and ligated at cervical level. A PE-320 cannula was introduced into the stomach through an incision in the duodenum and was ligated about 0.5 cm from the pylorus. The stomach was flushed through the esophagus cannula via a peristaltic pump with 10 ml saline at room temperature and then irrigated with saline. Acid output was determined by titration of the flushed perfusate with 0.01 N NaOH to pH 7.0. Basal secretions were collected for 45 min before infusion of pentagastrin (8 micrograms/ml/300 g BW) for 30 min, then for an additional 75 min. Blood samples were collected via jugular catheter at 0 min and 150 min following acid collection. Pentagastrin infusion stimulated gastric acid secretion in both diabetic and normal rats. The spontaneous gastric acid secretion in diabetic rats was not significantly different from that in normal animals. However, the secretion of gastric acid in response to pentagastrin was greater (p less than 0.05 to p less than 0.01) at 20, 30, and 35 min following pentagastrin infusion in diabetic rats than in normal females. Pentagastrin infusion stimulated gastric inhibitory polypeptide (GIP) secretion by 1.8-fold (p less than 0.05) in normal but not diabetic rats. The basal level of plasma GIP was higher (p less than 0.05) in diabetic than in normal rats. These results suggest that the increase of pentagastrin-induced gastric acid output in STZ-diabetic rats compared with normal controls is independent of GIP secretion.

Animals↗
PubMed1991

Hepatitis B virus DNA in cervicovaginal cells.

Hepatitis B virus DNA sequences were detected in seven (12.1%) of 58 cervicovaginal cell specimens that were obtained from pregnant women by polymerase DNA amplification assay. The presence of hepatitis B virus DNA in these cells raises the possibility that infected cervicovaginal cells may be a source through which hepatitis B virus can be transmitted from infected mothers to their newborns and between heterosexual partners.

Base Sequence↗
PubMed1990

Recurrent herpes simplex virus type 1 infection precipitated by the impaired production of interleukin-2, alpha-interferon, and cell-mediated cytotoxicity.

In order to understand whether immunosuppression due to the primary host defense defect provokes the reactivation of herpes simplex virus type 1 (HSV-1), 11 healthy persons were evaluated immunologically after recurrence of herpes. A decrease was found in the production of interleukin-2 (IL-2) and alpha-interferon (IFN-alpha) to HSV-1 antigen stimulation in the recrudescent stage (0 to 3 days after onset of the lesion). The cell-mediated cytotoxicity also decreased. To clarify the relationship between the immunosuppression and the occurrence of herpes recurrence, a further longitudinal study was undertaken measuring IL-2, IFN-alpha production, and cell mediated cytotoxicity every other week in 12 persons who suffered frequently from recurrent HSV-1 infection. IL-2 and IFN-alpha production after HSV-1 antigen stimulation and cell-mediated cytotoxicity before recurrence of herpes were lower than those without recurrence. These defective immunologic responses were persistent and became more pronounced during the recrudescent phase. The results suggest that the defect in the immunologic responses to HSV-1 antigen is related to the recurrence of herpes simplex.

Antigens, Viral↗
PubMed1990

Experimental infection of Thailand Taenia (Chiengmai strain) in domestic animals.

Twenty-five gravid proglottides of a Thailand Taenia were obtained from a patient in Chiengmai, Thailand, and brought to our laboratory. The tapeworm was determined to be T. saginata-like by counting uterine branches (mean number 16, range 12-19 on each side). The eggs from these proglottides remained infective under storage at room temperature for 14 days followed by refrigeration (4-8 degrees C) for 131 days. Eight Small-Ear-Miniature pigs and two Holstein calves were each fed with 3000 eggs and sacrificed 12-76 days afterwards. Six pigs became infected and 16 cysticerci were recovered from the livers. Thirteen degenerated/calcified cysticerci were also recovered from the livers of the two calves. More cysticerci were found in the liver parenchyma (55%) than on the liver surface (45%) of the infected animals. Measurements of length, width, diameters of protoscolex, rostellum and sucker and hooklet pattern show that Thailand Taenia is similar to Taenia from Taiwan, Korea and Indonesia but different from T. saginata and T. solium. These findings indicate that Thailand Taenia, Taiwan Taenia, Korea Taenia, and Indonesia Taenia may be of the same species or sub-species.

Animals↗
PubMed1990

The effect of cyclosporine on expression of class II major histocompatibility complex antigens on bronchoalveolar cells and peripheral blood mononuclear cells.

To evaluate the effect of cyclosporine (CsA) on the expression of class II major histocompatibility complex (MHC) antigens on bronchoalveolar cells (BAC) and peripheral blood mononuclear cells (PBMC), BAC and PBMC were obtained from mongrel dogs before and during CsA treatment. Expression of MHC class II antigens on BAC and PBMC were detected by monoclonal antibodies (Mabs) B1F6, 7.5.10.1 and Q5/13, which recognized canine MHC class II antigens, using cytofluorometry. Total cell counts and cell differentials of canine BAC showed no significant difference before or during CsA treatment (P greater than 0.05). Anti-MHC class II Mabs used in this study reacted with 21-51% of canine BAC and with 31-69% of PBMC. After stimulation with phytohaemagglutinin (PHA) the percentages of MHC class II positive BAC and PBMC were significantly increased (P less than 0.001). Whole blood levels of CsA were 315 +/- 76 (mean +/- SD) ng/ml and 343 +/- 57 ng/ml on days 7 and 14 during CsA treatment at an oral dose of 20 mg/kg/day. During CsA treatment there was no significant difference in the percentages of MHC class II positive BAC and PBMC compared with data obtained before CsA treatment (P greater than 0.05). We likewise failed to observe a suppressive effect of CsA on the increased expression of MHC class II antigens on BAC and PBMC induced by PHA (P greater than 0.05). In summary, at an oral dose of 20 mg/kg/day for a period of two weeks, our results show that: (1) CsA does not affect the total cell counts and cell differentials of canine BAC; (2) CsA does not reduce the basal expression of MHC class II antigens on canine BAC and PBMC; (3) CsA does not suppress the increased expression of MHC class II antigens on canine BAC and PBMC induced by PHA.

Animals↗
PubMed1990

MHC class II antigens on canine bronchoalveolar cells.

To evaluate the expression of MHC (major histocompatibility complex) antigens on canine bronchoalveolar cells (BAC), bronchoalveolar lavages (BAL) were performed in mongrel and German shepherd dogs. MHC class II antigens on canine BAC and peripheral blood mononuclear cells (PBMC) were detected by monoclonal antibodies (mAbs) B1F6, 7.5.10.1 and Q5/13 recognising canine MHC class II antigens, using cytofluorometry. These mAbs reacted with more than 20% of BAC and PBMC in both breeds of dog. The percentage of MHC class II positive cells in BAC were lower than those in PBMC. There was no significant difference in the percentages of MHC class II positive BAC and PBMC in mongrel and German shepherd dogs. To further identify the expression of MHC class II antigens on BAC, the cells were separated into adherent and nonadherent cells by petri dish adherence. The percentages of MHC class II positive cells in adherent and non-adherent cell populations were similar. Nearly half the lymphocytes in normal BAC were T cells detected by mAbs F3-20-7 and 1A1; B cells were scarce and represented less than 10% of nonadherent cells. Immunoprecipitation by anti-MHC class II mAbs, and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) revealed MHC class II-like molecules on canine BAC and PBMC. After stimulation with phytohaemagglutinin (PHA), the percentages of class II positive cells in BAC and PBMC were significantly increased. Thus, these anti-MHC class II mAbs may prove to be of advantage in experiments designed to evaluate the changes in class II antigen expression on canine BAC during the course of immune response in the lung, as in pulmonary allograft rejection.

Animals↗
PubMed1990

Cystic dilatations within the pelvis in patients with ipsilateral renal agenesis or dysplasia.

A total of 13 cases of cystic dilatations in the pelvis with ipsilateral renal agenesis or dysplasia was detected during renal ultrasonic mass screenings among 280,000 children within the last 2.5 years. The frequency was approximately 0.00464%. These anomalies included 7 cases of Gartner's cyst and 6 of seminal vesicle cyst. Sonographically, the cystic dilatations displayed a typically cystic nature with no internal echoes. The cysts were located laterally or posteriorly to the bladder, and the cystic mass protruded into or was behind the bladder and sometimes bulged the bladder wall. The dysplastic kidney in the patients with ipsilateral cystic dilatations was not detected by sonography due to its small size and the fact that it was obscured by bowel gas or overlying tissue densities. Three cases of dilated ureter communicating with the cyst were found on sonography. Since ultrasonic examination is an excellent method to identify a fluid-filled cystic structure, ultrasonography has become an important modality in the early detection, diagnosis and followup of these cystic dilatations.

Child↗
PubMed1990

The pig as an intermediate host for Taiwan Taenia infection.

Eggs (1000-100,000/animal) of Taiwan Taenia were inoculated per os into 14 Small-Ear-Miniature (SEM), 19 Landrace-Small-Ear-Miniature (L-SEM), and 5 Duroc-Yorkshire-Landrace (DYL) pigs. These animals were sacrificed 7-107 days after infection. Thirty-four pigs were found to be infected with Taiwan Taenia cysticerci and the infection rates of SEM, L-SEM, and DYL were 86%, 89% and 100% respectively. The cysticerci recovery rates of SEM, L-SEM and DYL pigs were 27.2%, 1.7% and 0.27% respectively. Cysticerci were recovered only from the livers and none were found in muscles, viscera or other parts of the carcasses. More cysticerci were located in the liver parenchyma (71%) than on the liver surface (29%). Taiwan Taenia cysticerci were smaller than those of classical T. saginata or T. solium. Moreover, Taiwan Taenia cysticerci had 2 rows of rudimentary hooklets on the scolex. The results of this study indicate that young pigs are good intermediate hosts for Taiwan Taenia and that the SEM pig is a satisfactory host for experimental studies with this tapeworm. These results were similar to other studies with different geographic strains of the T. saginata-like tapeworm in the Far East. These strains appear to be the same and possibly a new species.

Animals↗
PubMed1990

Detection of human papillomaviruses in cervicovaginal cells using polymerase chain reaction.

The polymerase chain reaction (PCR) was used to identify human papillomavirus (HPV) in cervicovaginal cells in normal individuals and in patients with cervical intraepithelial neoplasia (CIN). By use of a set of primers encoding the E6 region of the HPV genome, the presence of HPV DNA was demonstrated in the cervicovaginal cells of 43 (42.2%) of 102 normal individuals and in all 12 CIN patients. High sensitivity of the PCR method produced an additional 9 positive results on second sampling from 48 individuals who were initially HPV-negative. On the other hand, 26 (24.3%) of 107 HPV-positive individuals were HPV-negative when sampled a second time 5-7 days later. The data suggested that retest probably should be considered for patients clinically suspected of having HPV infection whose initial test results are negative for HPV DNA. Also, single HPV DNA-positive results should be accepted with caution.

Base Sequence↗
PubMed1990

Increased expression of MHC class II antigens in rejecting canine lung allografts.

Expression of major histocompatibility complex class II antigens was investigated in the normal lungs and in lung allografts of mongrel dogs after single-lung transplantation. Cryostat sections were stained with an indirect immunoperoxidase technique that used B1F6 and 7.5.10.1 as anti-MHC class II monoclonal antibodies. In the normal lungs and native lungs of the recipient dogs after single-lung transplantation, only some cells of lymphoid tissue and macrophages/dendritic cells were MHC class II-positive. During acute rejection, increased infiltration with MHC class II-positive cells in perivascular, peribronchial, and interstitial areas and intraalveolar spaces was found in lung allografts. In addition, expression of MHC class II antigens was induced on the bronchial epithelium and vascular endothelium. Induced expression of MHC class II antigens on the bronchial epithelium and vascular endothelium in rejecting lung allografts was found as early as two days after single-lung transplantation. The intensity of MHC class II antigen expression on bronchial epithelium and vascular endothelium in graft lungs increased with the progression of rejection response and directly correlated with the bronchoalveolar lavage fluid (BALF) levels of biochemical markers, as tumor necrosis factor alpha, gamma-interferon (IFN-gamma), interleukin 2 (IL-2) and soluble interleukin 2 receptor (SIL-2R). Abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium and abnormal elevation of BALF levels of the cytokines in lung allografts could be prevented by cyclosporine (CsA) treatment. Our results suggested that MHC class II antigen expression could be induced on the bronchial epithelium and vascular endothelium of canine lung allografts during acute rejection. This abnormal expression of MHC class II antigens on bronchial epithelium and vascular endothelium of graft lungs may serve as a specific index for diagnosis of lung allograft rejection when infection as an inducing factor can be excluded. Furthermore, bronchial epithelium and vascular endothelium of lung allografts have become MHC class II-positive, and are likely to be the targets for low-grade rejection, resulting in the development of bronchiolitis obliterans and occlusive vascular disease in lung allografts.

Animals↗
PubMed1990

Structure and immunological properties of thymosin beta 9 Met, a new analog of thymosin beta 4 isolated from porcine thymus.

During the course for the studies of thymosin beta 4 and prothymosin alpha from porcine thymus, a new analog of thymosin beta 4 has been identified. This peptide consists of 41 amino acid residues. The amino terminus is blocked by an acetyl group as revealed by fast atom bombardment mass spectrometric analysis. Amino acid sequence studies disclosed that this peptide is identical to bovine thymosin beta 9 except that leucine at position 6 in beta 9 is substituted by methionine. Thus, this new peptide has been termed thymosin beta 9 Met. The recoveries of beta 9 Met, beta 4, and prothymosin alpha in porcine tissues have been determined (in micrograms/g tissue) as follows: thymus (43, 85, 133); spleen (68, 203, 37); liver (10, 31, 27); heart (1.5, 10, 0); kidney (5, 51, 37); brain (0.8, 31, 5). Biologically, thymosin beta 9 Met was found to be more active than beta 4 in enhancing gamma-interferon production in cord blood lymphocytes. However, beta 4 appeared to stimulate higher amounts of interleukin 2 and tumor necrotic factor. The significance for the coexistence of two homologous peptides with similar functions in the thymus and a number of other organs is not clear, and deserves further investigation.

Amino Acid Sequence↗