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Biomedical subjects

C Y Lin

Publications and source records attributed to C Y Lin.

At least 379 records · Page 21Linked to original sources

Immunomodulation of influenza virus infection in the precipitating asthma attack.

Twelve asthmatic children (ages four to ten years) had attacks of asthma associated with influenza infection during the spring of 1985. Virus isolation and serologic studies proved eight cases were A/Philippine/2/82 (H1N2) and four cases were B/USSR/100/83. Four cases of A/Philippine/2/82 and two cases of B/USSR/100/83 were isolated from six control subjects who had suffered from influenza infection without asthma attack. The absolute lymphocyte count, T cell subsets increased in influenza patients both with and without asthma attack. However, the OKT4/OKT8 ratio markedly decreased in the influenza with asthma group during the acute phase. Since the fresh asthmatic patients had decreased OKT4/OKT8 ratio and increased lympho-proliferative response, IL-2 production increased after their lymphocytes were stimulated with housedust antigen and returned to near normal after hyposensitization therapy. Therefore, these results suggest that influenza virus has asthmagenicity and may contribute to precipitating an asthma attack.

Adolescent↗

Four equivalent sets of mixed-model equations with relationship matrix for estimation of genetic parameters.

Four equivalent approaches of estimating variance components from mixed-model equations including the relationship matrix are presented. One procedure involves simultaneous diagonalization of the coefficient matrix (Z'MZ) and the inverse of the numerator relationship matrix (A-1). After simultaneous diagonalization, the absorbed coefficient matrix of the mixed-model equations is diagonal, so solving the mixed model equations and estimating variance components become trivial computations. A numerical example is given to illustrate the computational aspects of the simultaneous diagonalization approach and to demonstrate that the four approaches yield identical results. The simultaneous diagonalization approach eliminates direct inversion of the coefficient matrix for each iteration and thus requires much less computer time. The advantage of this approach over that of direct matrix inversion in terms of computer time increases with increasing levels of random effects and increasing rounds of iteration. Application of simultaneous diagonalization to maximum likelihood estimation also is discussed.

Animals↗

Age and Zebu-Holstein additive and heterotic effects on lactation performance and reproduction in Brazil.

Data of 6482 lactations from 14 crossbred (Holstein x Zebu) herds in Brazil were used to study breed additive and heterosis effects for first, second, third, and first to fifth lactation milk yields, age at first calving, calving interval, and milk yield divided by calving interval, as well as the effect of age at calving on milk yield. Holstein additive expressed as deviation from Zebu and heterosis effects were highly significant for all traits. For each percentage of Holstein gene contribution an increase of 10.02, 12.02, 12.51, and 12.15 kg of milk were expected for first, second, third, and first to fifth lactation yields, respectively. Corresponding heterosis effects on those traits were 3.80, 3.39, 4.02, and 3.90 kg of milk for each percentage of heterozygosity. Replacement of pure Zebu genes by Holstein genes reduced age at first calving by 6 mo and shortened calving interval by 37 d. Holstein x Zebu heterotic effect decreased age at first calving by 2 mo and calving interval by 39 d. Holstein additive and heterosis effects for milk yield divided by calving interval were 3.4 and 1.3 kg of milk/d, respectively. Fitting breed additive and heterozygosity effects accounted for 99% of the genetic effects except for first to fifth lactation milk yield.

Aging↗

Growth and feed efficiency of pureline and crossline dairy heifers.

Data on 3957 heifers from the Holstein H line, Ayrshire-based A line, and C line (crossbreds between H and A lines) were used. Growth, feed consumption, and feed efficiency from 26 to 34 wk were examined. The full model included the fixed effects of herd, year of birth, season of birth, and additive, maternal, and heterotic genetic effects with 26-wk weight as a covariate. Heterotic and maternal effects were not significant. Adjusted for the 26-wk weight covariate, H line heifers gained 3 kg more than A line heifers with C line heifers intermediate. Adjusted for 26 and 34-wk weight covariates, H line heifers ate 2 kg less TDN than A line heifers and, hence, were more efficient. Correlations among traits were estimated using the residual variance-covariance matrix from the full model. Body weight at 34 wk was correlated with 26-wk weight (r = .88) but essentially independent of rate of gain (r = .02). It was correlated with feed consumed (r = .51) and negatively associated with gain/feed consumed (r = -.25). Gain was correlated (r = .84) with gain/feed consumed but mildly so (r = .28) with feed consumed. Feed consumption was negatively correlated (r = -.25) with gain/feed consumed when the 26-wk weight covariate was included but became much larger (r = -.95) when both 26 and 34 wk weight covariates were included. Although genetic differences in feed consumption and feed efficiency of growing heifers exist, these are small and closely associated with weights and weight gains.

Animal Nutritional Physiological Phenomena↗

Factors affecting length of herdlife in purebred and crossbred dairy cattle.

The proportional hazards model with censoring was used to assess the effects of breeding value, disease, calving, size, and udder and lactation traits on length of herdlife of 3881 heifers in five herds. Data were recorded over 10 yr from three lines: a Holstein line, an Ayrshire-based line, and a crossbred line. Influences on survival were assessed from data collected at birth, 34, 50, and 82 wk, first freshening, and at 112 and 308 d postpartum. Median estimated herdlife (age at 50% culling) was 3.9 yr for animals alive at first freshening and increased to 4.3 yr for those that completed a first lactation (308 d postpartum). Herds differed greatly in the pattern of culling after freshening. Crossbred females had 21 wk longer median estimated herdlife than the mean of the purelines at 308 d postpartum. Individual milk yield was positively associated with longevity and had the greatest impact on length of herdlife. Abortion and fertility measured as days to last insemination were negatively associated with length of herdlife. Large heifers tended to have increased longevity. High feed intake postpartum was associated with reduced length of herdlife. Objective measures of conformation, which included measurements of the udder, were not important in determining herdlife.

Animals↗

Age-constant versus weight-constant feed consumption and efficiency in broiler chickens.

Weekly body weights, feed consumption (FC), and feed efficiencies (FE = gain:feed) of 148 male and 125 female broilers were measured individually between 2 and 7 wk of age. Multiple regression analyses of these traits were performed to examine the influence of body weight, weight gain or feed consumption, age, and individual broiler differences. Four different measures of FC and FE from 4 to 6 wk of age were compared within sex: age-constant FC and FE; weight-constant FC and FE; age-constant-weight-corrected FC and FE; and weight-corrected FC and FE, which estimate weight-constant measures. Much of the variation (85 to 90%) among broilers in FC and FE was due to age and body weight differences. Partial regression coefficients indicated that increased body weight at commencement of testing was associated with increased FC and reduced weight gain and FE. Correlations between age-constant and weight-constant FC were zero. This indicates the two forms have little in common. Correlations of body weights and weight gain with FC were negative (-.5 to -.8) for weight-constant values but positive (.5 to .8) for age-constant values. Hence, correlations of the correct (weight-constant) measure of FC with body weights indicate that faster growth gives rise to lower broiler feed consumption. Age-constant and weight-constant FE values were positively correlated (.8 to .9); however, the latter values had larger correlations with body weights and weight gain. These results emphasize the need to correct age-constant FC and FE for body weight differences in order to evaluate differences in efficiency among broilers more accurately.

Age Factors↗

An outbreak of schistosomiasis japonica in Taiwan.

The present study was undertaken to determine the current status of Schistosoma japonicum infection in the newly found endemic focus at Hanpao Farm, Fangyuan District, Changhua County, West-Central Taiwan. Two field surveys and one laboratory investigation were conducted from July to October 1987. Of 705 snails examined by shedding and crushing methods, 17.0% were found to harbor cercariae of S. japonicum. By sodium sulfate-acid-ether-triton centrifugal sedimentation technique, 25% of 16 cattle, 40% of 5 goats, and 50% of 4 dogs were found to be positive for S. japonicum eggs. In the laboratory, 21 mice were exposed to cercariae from single naturally infected snails. Following inoculation, 7 mice died early, 7 were found infected with male worms, 2 with female worms, and 1 with bisexual infection. The results of the present study indicated that the infection rates of snails and domestic animals are higher than those previously reported from elsewhere in Changhua County.

Animals↗

[T-cell subpopulation of bronchoalveolar lavage fluid in patients of sarcoidosis and hypersensitivity pneumonitis--2 cases report].

Diffuse interstitial lung diseases include more than 100 varieties. Even for a chest specialist differential diagnosis is difficult; accurate diagnosis without transbronchial lung biopsy or open lung biopsy was particularly hard. Bronchoalveolar Lavage (BAL) is a new diagnostic procedure which is relatively safe and repeatable. It takes about 30 minutes more, during the usual bronchoscopic examination, to obtain fluid and cells from the lower respiratory tract. These specimens aid differential diagnosis and an understanding of pathogenesis in the early stage of diffuse interstitial lung disease. Two cases are reported. One was sarcoidosis, as proved by mediastinoscopic lymph node biopsy; the other one was hypersensitivity pneumonitis by clinical impression. Both patients received bronchoscopic examination with bronchoalveolar lavage. The bronchoalveolar lavage fluid showed an increase in total cell count, lymphocyte count and lymphocyte percentage. In sarcoidosis, the main T-lymphocyte subpopulation was helper T-lymphocytes while, in hypersensitivity pneumonitis, the main T-lymphocyte subpopulation was suppressor T-lymphocytes. We concluded that, if the patients of diffuse interstitial lung diseases had increased lymphocyte count and percentage in bronchoalveolar Lavage fluid, examination of the lymphocyte subpopulation would help differential diagnosis.

Adult↗

A prospectively randomized trial of heat probe thermocoagulation versus pure alcohol injection in nonvariceal peptic ulcer hemorrhage.

We conducted a prospectively randomized trial of 78 patients with peptic ulcer hemorrhage to evaluate the hemostatic effects of heat probe thermocoagulation and pure alcohol injection. The initial and ultimate success rates of heat probe thermocoagulation were better than those of pure alcohol injection (p less than 0.05). Rebleeding rates and success rates of retreatment in the two groups were not significantly different. In the case of a spurter or a bleeder located over the lesser curvature side of the stomach or superior wall of the duodenal bulb, heat probe thermocoagulation was better than pure alcohol injection in achieving hemostasis. We conclude that heat probe thermocoagulation is better than pure alcohol injection in arresting peptic ulcer hemorrhage. If the bleeder is a spurter or is located over the lesser curvature side of the stomach or superior wall of the duodenal bulb, heat probe thermocoagulation is the treatment of choice.

Adult↗

Metabolism of cis-12-octadecenoic acid and trans-9,trans-12-octadecadienoic acid and their influence on lipogenic enzyme activities in mouse liver.

High carbohydrate (65% glucose) diets containing cis-12-octadecenoic acid (12c-18:1) or trans-9,trans-12-octadecadienoic acid (9t,12t-18:2) were fed to weanling mice to investigate the influence of fatty acid structure on six hepatic enzyme activities involved in lipid metabolism. Results with these diets were compared to those with diets containing no fatty acids, saturated fatty acids; cis-9-octadecenoic acid (9c-18:1) and cis-9,cis-12-octadecadienoic acid (9c,12c-18:2). These comparisons show saturated fatty acids, 9c-18:1, 12c-18:1, and 9t,12t-18:2, had little or no influence on the activity levels of fatty acid synthetase, malic enzyme (EC 1.1.1.40)citrate cleavage enzyme (EC 4.1.3.8), glucose-6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 1.1.1.44) and acetyl-CoA carboxylase (EC 6.4.1.2). Neither 12c-18:1 nor 9t,12t-18:2 produced the dramatic enzyme-lowering effect exhibited by the diet containing 9c,12c-18:2 when compared to the diet devoid of fat. Thus, both the 9 and 12 bonds must be present in the same molecule. Also, at least one and probably both bonds must be in the cis configuration to depress liver enzyme activities. Capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were both used for analysis of the methyl esters derived from the hepatic lipids. The GC and GC-MS data provided (a) direct evidence for incorporation of both isomers into hepatic lipids and (b) indirect evidence that 9t,12t-18:2 lowered liver delta 9-desaturase activity. In addition, since these products were found in the complex liver lipids, there is no doubt that the various enzymes concerned with activation and acylation utilize both of these isomeric fatty acids as substrates.

Animals↗

Calcium homeostasis in premature infants and treatment of early hypocalcaemia by 1,25-dihydroxycholecalciferol.

We studied calcium homeostasis and the serum calcium response to oral 1,25-dihydroxycholecalciferol [1,25 (OH)2D3] at a low pharmacological dosage of 0.1 microgram/kg daily in 14 early hypocalcaemic asymptomatic neonates. Seven hypocalcaemic neonates were not treated. In hypocalcaemic neonates serum PTH levels were normal, the urinary C-AMP response after PTH stimulation was poor and plasma 1,25 (OH)2D3 was low. Treatment with 1,25(OH)2D3 resulted in a rapid increase of serum calcium. The increase was more rapid in neonates treated with 1,25(OH)2D3 than in untreated subjects. A similar result was obtained in one of a pair of identical twins. These results suggest that a low dose of 1,25(OH)2D3 is effective in treating neonatal hypocalcaemia. However, the response was delayed for 48 h. The reason for this delay is not clear.

Calcitriol↗

Pompe's disease in Chinese and prenatal diagnosis by determination of alpha-glucosidase activity.

We measured the activities of two major forms of alpha-glucosidase in lymphocytes and cultured fibroblasts from normal healthy controls and patients with Pompe's disease by using 4-methylumbelliferyl-alpha-D-glucoside as substrate. We found (1) enzyme activity of the pH 4 and pH 6 forms varied with age, and (2) patients with Pompe's disease showed very low activity of the pH 4 form and a low ratio of pH 4 to pH 6 forms. We established a reference range and were also able to diagnose prenatally the homozygote and heterozygote forms of Pompe's disease which occurred in families of southern Chinese and aborigines in Taiwan. This enzyme biochemical study may be useful in anthropology.

Age Factors↗

Characterization of a genetic difference in the platelet aggregation response of two inbred mouse strains, C57BL/6 and C3H/He.

An in vitro platelet aggregation assay has been used to characterize the platelet response of two inbred mouse strains, C57BL/6J and C3H/J. Arachidonic acid, ADP, ristocetin, and collagen, but not epinephrine, were effective inducers of platelet aggregation in C57BL/6 mice. In C3H mice, however, platelets responded differently to some, but not all, inducers of platelet aggregation. The difference between the two strains was particularly striking for arachidonic acid; at 0.375 microM arachidonic acid, platelets from C57BL/6 mice aggregated well, but platelets from C3H mice failed to aggregate. The two strains also differed in serotonin release from platelets. When the pool of platelet serotonin was labeled by incubating platelets with [14C]serotonin, the amount of label subsequently released from platelets in response to 0.375 microM arachidonic acid was 20.5% +/- 2.5 SE for C57BL/6 mice and 1.5% +/- 1.5 SE for C3H mice. The platelets from F1 progeny of a cross between C57BL/6 and C3H mice were indistinguishable in aggregation response from the C57BL/6 parent. The defect in aggregation response found in C3H mice appears to reside in the platelets rather than in the plasma. Experiments which involved adding the plasma of one strain to the washed platelets of the other strain indicated that C57BL/6 platelets aggregated well whether they were resuspended in plasma from C57BL/6 or C3H mice, while C3H platelets failed to aggregate regardless of the origin of the plasma. Strain C57BL/6 is susceptible to diet-induced formation of atherosclerotic lesions, but strain C3H is resistant to lesion formation. This genetic difference in atherosclerosis susceptibility is not related to the genetic difference in platelet aggregation since a recombinant inbred strain, BXH-9, is susceptible to atherosclerosis like the C57BL/6 parent but has the reduced platelet aggregation response of the C3H parent.

Animals↗

Natural killer cell activity in lung cancer patients.

A total of 50 lung cancer (CA) patients and 20 normal persons as controls were included in our study. We obtained lymphocytes from heparinized blood by Ficoll-Hypaque gradient method, and after the macrophages were removed, they were incubated with 51Cr-labelled K562 cells at concentrations of 100:1, 50:1, 12.5:1 for four hours. We calculated the cytotoxicity activity and lytic unit (LU) of natural killer (NK) cells. Significant impairment was noted in the comparison of NK cytotoxicity and LU between stage III-M1 lung CA patients (n = 28) and the control group. However, significant impairment was also noted in stage III-M1 and III-M0 patients. Four cases in stage I underwent surgery, and the NK cytotoxicity before the operation was noted to be low. After the operation, the NK cytotoxicity increased. These results indicate that NK cytotoxicity assay was impaired in stage III-M1 lung CA and also suggest that it may act as a therapeutic guide in determining the results of the operation.

Adult↗

Association of milk protein types with growth and reproductive performance of dairy heifers.

A total of 890 heifers was used to study the effects of four milk protein loci (alpha S1-casein, beta-casein, kappa-casein, and beta-lactoglobulin) on heifer growth and reproduction. The additive effects of gene substitutions at the four milk protein loci were significant only in 4 of 56 cases for all traits studied. Dominance effects at alpha S1-casein, beta-casein, and kappa-casein loci were not significant for any traits except beta-casein locus on body weight at first calving. Heifers with AB type of beta-lactoglobulin showed greater body weights and measurements and gestation length than the AA or BB type, indicating an overdominance effect. Heifers with AB type of beta-lactoglobulin were significantly younger at first conception and at first freshening and had fewer number of days from first service to conception than the AA or BB type, indicating underdominance effect. Thus, beta-lactoglobulin locus shows overdominance, underdominance, or no dominance, depending upon the traits considered. The four milk protein loci contributed more dominance variance than additive variance to total phenotypic variance. This might account for the existence of milk protein polymorphism in the cattle population. The combined genotypes of the four milk protein loci showed significant effects on 2 of 14 traits studied.

Animals↗