PubMed Health⌕ Search

Biomedical subjects

T M Lin

Publications and source records attributed to T M Lin.

At least 91 records · Page 5Linked to original sources
PubMed1984

Immunological application and implication of pregnancy proteins.

Five pregnancy proteins which were discovered by immunological methods at our and two other laboratories were reviewed. These proteins have been purified, physico-chemically characterized, histologically localized and measured by immunological procedures in normal as well as certain abnormal pregnancies. They have been studied for their use as markers in the detection of certain tumors and for monitoring various abnormal pregnancies. Their possible functions as carriers for hormones and metals, in the coagulation system, and in immunological protection of the fetus from the maternal homograft rejection mechanism have also been investigated.

Animals↗
PubMed1983

An enzyme-linked immunoassay for circulating immune complexes using solid phased goat Clq.

An ELISA procedure was developed for measuring circulating immune complexes (IC), using solid phased goat Clq. The use of purified Clq from this species significantly diminished the background uptake of the enzyme-labeled goat antibodies used in the assay, in comparison with Clq isolated from human, guinea pig or rabbit serum. The test specimen results are reported as micrograms equivalent (microgram eq)/ml of heat aggregated human immunoglobulin G (HAIgG), and are based on standard curves developed with this latter reagent for each assay. The 2 World Health Organization (WHO) reference preparations for immune complex determinations (HAIgG and a human tetanus antitoxin-toxoid immune complex) were assayed by this ELISA procedure, and the results obtained were in very good agreement with the WHO established values. All the reagents in the ELISA, including the lyophilized HAIgG standard and the solid phased Clq are stable for more than one year at 4 degrees C. The range of accurate quantitation in test serum is 2-500 micrograms/ml, when using a 1:100 specimen dilution. The total incubation is less than 2 h, with no preliminary preparation of test specimens. The average concentration of IC reactivity in 126 healthy adults was 6 micrograms eq/ml, and the normal upper limit was determined to be 12 micrograms eq/ml.

Adult↗
PubMed1983

Age at any birth and breast cancer risk.

In an effort to assess the relative importance of age at first birth, age at subsequent births, and total parity to the occurrence of breast cancer, reproductive data from 4,225 women with breast cancer and 12,307 hospitalized women without breast cancer were analyzed by a multiple logistic regression model. Age at first birth was confirmed to be the most important reproductive risk indicator; it was associated with a 3.5% increase of relative risk for every year of increase in age at first birth (the 95% confidence interval of this estimate was 2.3 to 4.7% increase per year). However, age at any birth after the first was also an independent and statistically significant risk indicator; it was associated with a 0.9% increase of relative risk for every year of increase in age at any (and every) birth (the 95% confidence interval of this estimate was 0.4 to 1.5% increase per year). There is evidence that the age of approximately 35 years represents for every birth a critical point; before this age any full-term pregnancy confers some degree of protection; after this age any full-term pregnancy appears to be associated with increase in breast cancer risk. The effect of parity is determined by the age of occurrence of the component pregnancies. While most pregnancies occur under the age of 35, the distribution varies from population to population, and this may account for the differences between populations in whether or not a protective effect is seen for births after the first, and if it is seen, its extent.

Adolescent↗
PubMed1983

Action of somatostatin on stomach, pancreas, gastric mucosal blood flow, and hormones.

In dogs gastric secretion induced by tetragastrin and pancreatic secretion induced by secretin and/or cholecystokinin were inhibited by somatostatin at doses of 0.06-1 microgram X kg-1 X h-1 and 0.06-1 microgram X kg-1 X 0.5 h-1, respectively. Inhibition was a linear function of the logarithm of dose. Basal and 2-deoxy-D-glucose-induced gastric acid secretion was also significantly inhibited by low doses of somatostatin. Results in this study differ from those reported previously by clarifying the action of somatostatin as follows. 1) The inhibitory effect of somatostatin on pancreatic protein secretion was significantly greater than that on water and bicarbonate production. Somatostatin was more effective on cholecystokinin- than secretin-induced pancreatic secretion. 2) Although gastric mucosal blood flow (MBF) was affected by somatostatin, the reduction of MBF was not the primary mechanism responsible for its inhibitory action. 3) The low doses of somatostatin used in this study significantly inhibited gastric and pancreatic secretion without affecting the basal plasma concentrations of insulin, glucagon, growth hormone, gastrin, or secretin in the dogs, suggesting that the inhibitory action was not mediated by changes or reduction in plasma concentration of these hormones.

Animals↗
PubMed1982

Inhibitory effect of glucagon on gastric acid secretion induced by methacholine, insulin, tease-feeding and antral distention in dogs.

Acid secretion from Heidenhain pouches of dogs stimulated by methacholine was inhibited 34 to 45 per cent by glucagon (25 micrograms/kg subcutaneously or 25 micrograms/kg/hr by continuous intravenous infusion). Acid secretion induced by insulin was inhibited 25 to 62 per cent for 1 1/2 to 2 1/2 hr by a single s.c. dose of glucagon 10 micrograms/kg. Continuous intravenous infusion of glucagon 25 micrograms/kg/hr or of a hypertonic glucose solution (20 per cent w/v) reduced the response to 0.5 unit/kg of insulin by 78 to 84 per cent for more than 3 1/2 hr in 4 dogs with vagally innervated gastric pouch. The response to food teasing was decreased 66 to 99 per cent by 10 micrograms/kg of glucagon s.c. The acid response of vagally innervated fundic pouches to repeated distention of the pyloric region was completely abolished by 3 doses of 10 micrograms/kg. Glucagon is effective in inhibiting acid secretion induced by insulin, sham feeding and distention of the pylorus.

Animals↗
PubMed1981

Simple standardized enzyme-linked immunosorbent assay for human antibodies to Entamoeba histolytica.

A simple solid-phase enzyme-linked immunosorbent assay procedure for the detection of human antibodies to Entamoeba histolytica was developed which showed a high degree of correlation with the agar gel diffusion, counterelectrophoresis, and indirect hemagglutination methods, as well as with clinical data. The enzyme-linked immunosorbent assay is rapid (1 h 15 min, total incubation time), and the reported values are referenced to a positive control so that they correlate with levels of antibody sufficient to be detected by the gel diffusion methods. The enzyme-linked immunosorbent assay is highly reproducible, specific, and sensitive; it can be used qualitatively or quantitatively.

Animals↗
PubMed1980

Maternal age and birth rank of women with breast cancer.

Data from a large international case-control study of breast cancer suggested that women born to young mothers had a 25% lower risk of breast cancer. The association was not secondary to a tendency for these women themselves to have had children at early ages. The data provided no indication of a meaningful association between breast cancer risk and birth rank. Confounding was controlled by stratification according to a summary confounder score.

Adult↗
PubMed1980

Standardized quantitative enzyme-linked immunoassay for antibodies to Toxoplasma gondii.

A quantitative and standardized enzyme-linked immunosorbent assay is described which uses lyophilized antigen-coated disks for the detection of human antibodies to Toxoplasma gondii. It does not require serial dilution of the test specimen, and the objective absorbance readings are converted into international units per milliliter traceable to the World Health Organization's reference standard preparation of toxoplasma antibodies. It was shown to be highly specific, reproducible, and sensitive. The reagents were stable, without biohazard, and ready for use. Studies of various parameters in the assay indicated that the test conditions were relatively flexible. The enzyme-linked immunosorbent assay results correlated satisfactorily with the methylene blue dye test, the indirect immunofluorescence test, and the passive hemagglutination test.

Antibodies↗
PubMed1979

Interaction of factors associated with cancer of the nasopharynx.

A retrospective study of nasopharyngeal carcinoma (NPC) revealed that smoking, working under poor ventilation, use of nasal balms or oil for nasal and throat troubles, use of herbal drugs, and anti-EBV antibody titer were found statistically associated. The dural interactions of these factors to the risk of NPC were presented. Except in work conditions with poor ventilation and when herbal drugs are used, all the combinations were synergistic. The synergistic actions were especially remarkable with smoking and other factors. The possible etiological mechanisms of NPC are discussed.

Antibodies, Viral↗
PubMed1978

Immunological relationships of human and subhuman primate pregnancy-associated plasma proteins.

(1) Four pregnancy-associated plasma proteins cross-reactive with antibodies to the human pregnancy proteins were detected in several species of pregnant subhuman primates. In the case of the two apes studied (chimpanzee and orangutan), these appeared to be immunologically identical to the human PAPPs (PAPP-A, -B, -C, and HCS). In the old world monkeys analyzed, equivalent partially cross-reactive PAPPs were found; while in the new world squirrel monkey, only faint traces of cross-reactive PAPP-C and HCS were observed with the most sensitive methods used. (2) As in the human, these proteins appeared to be specific for pregnancy, not being detectable in nonpregnant animals, female or male. (3) The pregnant chimpanzee possessed significantly higher concentrations of PAPP-A and PAPP-C than did women at an equivalent stage of pregnancy, while the HCS and PAPP-B levels appeared to be approximately the same. (4) The primate PAPP-C analogues were more complex than human PAPP-C, often revealing multiple gel diffusion patterns with subfractions of differing electrophoretic mobilities. (5) Based on the changes of electrophoretic mobility upon exposure to neuraminidase, the subhuman primate as well as human PAPP-A and PAPP-C appeared to be glycoproteins containing sialic acid. (6) In the chimpanzee and rhesus monkey, as in the human, the levels of PAPP-A, PAPP-C, and HCS were appreciably higher during the third trimester of pregnancy than they were during the second trimester.

Animals↗
PubMed1978

Pregnancy-associated plasma proteins in pregnant and pseudopregnant rats.

As in the human, the rat pregnancy-associated plasma proteins consisted of four distinct entities as revealed by immunological methods. All showed gradual increases during gestation and rapid disappearance postpartum. They could be physicochemically, although not immunologically, tentatively related to the human pregnancy proteins. None of them was detectable in the serum of rats at various stages of pseudopregnancy, nor in nonpregnant rats.

Animals↗
PubMed1978

Characterization and purification of pregnancy-associated plasma protein B (PAPP-B).

PAPP-B is a pregnancy-specific beta 1-glycoprotein of large molecular weight, about 1,000,000 as determined by Sepharose 4B and 6B gel filtration. Its isoelectric point is between pH 4.6 and 5.0. It has been purified at least 800-fold from term pregnancy serum by a sequence of steps involving salting out at 30% saturation with ammonium sulfate (1,2M), DEAE-cellulose chromatography, Sepharose 4B gel filtration and hydroxylapatite chromatography. Monospecific antiserum to PAPP-B has been prepared, and used to differentiate it from several other newly reported tumor or pregnancy proteins. PAPP-B was found to increase slowly during the second trimester of pregnancy and more steeply during the third, reaching a plateau in late gestation. During the postpartum period, PAPP-B disappeared quite rapidly, with an apparent half-life of less than 1 day.

Blood Proteins↗
PubMed1977

Plasma concentrations of four pregnancy proteins in complications of pregnancy.

Toxemia of pregnancy was associated with an elevation of the pregnancy-associated plasma protein (PAPP)-A concentration, as compared to the level in normal pregnancy in the last month of gestation. The other pregnancy proteins measured were not altered in toxemia. In twin pregnancies, the PAPP-A, PAPP-C, and human placental lactogen levels were all increased, particularly PAPP-A. On the other hand, pregnancy zone protein was not affected by twinning. Pregnancy with diabetes showed normal levels of these proteins.

Blood Proteins↗
PubMed1977

Antibodies to Epstein-Barr virus capsid antigen and early antigen in nasopharyngeal carcinoma and comparison groups.

Antibodies to Epstein-Barr virus capsid antigen (anti-VCA) and early antigen (anti-EA) were measured in 263 patients with nasopharyngeal carcinoma (NPC), 624 age- and sex-matched neighborhood controls, 570 family members of NPC patients and 830 family members of neighborhood controls in Taiwan. The distribution of antibody titers was significantly different between NPC patients and the other three groups. More than 55% and 45% of NPC patients had titers of greater than or equal to 1:640 and greater than or equal to 1:80 for anti-VCA and anti-EA, respectively, while less than 6.7% and 2.5% of the other three groups had such high titers. The geometric means of anti-VCA and anti-EA titers were 1:352 and 1:45, respectively, in NPC patients compared to less than 1:77 and 1:12, respectively, in the comparison groups. Anti-VCA and anti-EA titers were significantly correlated. The association of EBV with NPC is discussed.

Antibodies, Viral↗