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Biomedical subjects

S L Yu

Publications and source records attributed to S L Yu.

At least 55 records · Page 3Linked to original sources
PubMed1995

Alveolar integrity in pulmonary emphysema using technetium-99m-DTPA and technetium-99m-HMPAO radioaerosol inhalation lung scintigraphy.

UNLABELLED: The alveolar integrity (AI) in 17 male patients with pulmonary emphysema (EMPH) diagnosed by chest x-ray was measured by 99mTc-DTPA and 99mTc-HMPAO radioaerosol inhalation lung scintigraphy. METHODS: The patients were divided into two groups: (A) nine patients with pulmonary emphysema and normal carbon monoxide diffusion capacity (DLCO) and (B) eight patients with pulmonary emphysema and abnormal DLCO. The degree of AI damage in EMPH was presented as the slope of the time-activity curves from the dynamic left lung imagings in DTPA and HMPAO. The AI of EMPH patients were compared with the AI of 16 normal controls. RESULTS: The results show that: (1) the slope of DTPA is larger than that of HMPAO in each of the portions of the left lung for any of the study groups; (2) statistical differences were found between the normal controls and EMPH patients in HMPAO but not in DTPA; and (3) the correlation was not good between DLCO and DTPA/HMPAO in EMPH patients. CONCLUSION: Our results suggest that: (1) at least two different mechanisms in the lungs were at work; (2) the AI damage in EMPH developed mainly in the lipophilic part of the alveoli; and (3) the AI damage presented as slopes of DTPA/HMPAO in our study was different from the traditional pulmonary function such as DLCO.

Administration, Inhalation↗
PubMed1994

Relationship of alveolar permeability and lung inflammation in patients with active diffuse infiltrative lung disease detected by 99Tcm-DTPA radioaerosol inhalation lung scintigraphy and quantitative 67Ga lung scans.

The alveolar permeability (AP) in 21 patients with active diffuse infiltrative lung disease (ILD) was measured by 99Tcm-diethylenetriaminapentaacetate (DTPA) radioaerosol inhalation lung scintigraphy. The degree of AP damage in ILD was presented as the slope (% min-1) of the time-activity curve from the dynamic lung image. Meanwhile, the quantitative Ga lung scan (GA) was performed as a Ga uptake index (GUI) to evaluate the severity of lung inflammation in active ILD. The results show that no good correlation between the degree of AP damage and lung inflammation was found. When the patients were divided into two groups of (A) eight active ILD with normal chest X-ray (X-ray) and (B) 13 active ILD with abnormal X-ray, there was no significant difference between groups A and B for the DTPA and Ga results. In conclusion, the relationship between the degree of AP damage and lung inflammation in active ILD is not significant. This was not consistent with X-ray findings. There was, however, a significant difference between those with ILD and normal controls.

Adult↗
PubMed1994

Lung inflammation in patients with systemic lupus erythematosus detected by quantitative 67Ga-citrate lung scanning.

The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.

Adult↗
PubMed1994

Correlates and predictive models for blood pressure values in residents of two communities in Taiwan.

Factors predicting systolic blood pressure (SBP) and diastolic blood pressure (DBP) were extensively studied in residents aged 18 years and above from 10 villages in two Taiwanese communities. In women, the associated factors identified included age, body mass index, waist/hip ratio (not selected as a factor for DBP), plasma uric acid, plasma chloride, urinary sodium/creatinine ratio, urinary calcium/creatinine ratio, education level, ancestral origin, parental hypertension status, and marital status. In men, the factors were age, body mass index, plasma triglyceride concentration, urinary sodium/creatinine ratio, smoking status, alcohol drinking status, parental hypertension status (not selected for DBP), and marital status (not selected for DBP). The degree of BP variation which could be significantly explained by the measured factors differed between SBP and DBP, and differed between men and women: 18% in men and 39% in women for SBP variation; 15% in men and 27% in women for DBP variation. Factors other than those included in the models should be explored, particularly for men. This study identifies, for Chinese populations, predictive factors of BP well-known in Western societies (BMI, urinary sodium, plasma uric acid, alcohol consumption) and factors less emphasized in other studies (plasma triglyceride and marital status). A positive association between BP and urinary Na, a lack of association between BP and urinary K, and opposite findings in the relationship between BP and the education level for men (positive relation) and women (negative relation) are worth noting.

Adolescent↗
PubMed1993

Expression and antigenecity of human immunodeficiency virus type-1 transmembrane protein gp41 in insect cells.

The HIV-1 transmembrane protein, gp41, is processed together with the envelope glycoprotein, gp120, from the same precursor, gp160, during the virus maturation. We used a baculovirus expression system to demonstrate that gp41 could be properly expressed without the preceding gp120 sequence. Two constructs with slight differences in the N-terminal region of gp41 were generated: one with a deletion of the first 7 hydrophobic residues of gp41, which have been suggested to be in a region important for membrane fusion and penetration, whereas the second with a complete sequence of gp41 except that a nonconserved leucine was substituted with a glutamine during DNA manipulation. Results from Western blotting with specific antisera confirm the gp41 identity. The sizes of gp41 were sensitive to tunicamycin treatment, indicating that N-linked glycosylation did occur. Further immunoblotting analyses with 90 different serum samples from HIV-1-infected individuals gave similar reaction patterns, suggesting that gp120 as well as the N-terminal region of gp41 are not critical for the expression and antigenecity of gp41. These eucaryotic constructs should provide valuable gp41 sources for detailed characterization of gp41 functions.

Amino Acid Sequence↗
PubMed1992

Detection of infectious bursal disease virus infection using the polymerase chain reaction.

The method of reverse transcription (RT) followed by the polymerase chain reaction (PCR) was used to amplify two different fragments of the infectious bursal disease virus (IBDV) genome. Two sets of primer framed two different regions within the genes coding for proteins VP2 and VP3, respectively. Both sequences were detected in five strains of IBDV, whereas, none were obtained from uninfected control cells. The sensitivity of RT-PCR was carried out on nucleic acids from the IBDV infected cell cultures. The detection limit was 10(0) to 10(-1) TCID50 in ethidium bromide stained gels and could be enhanced further to 10(-1) to 10(-3) TCID50 by hybridization after southern transfer. In addition, detection of IBDV infection in 12 out of 14 bursal specimens examined by this technique was shown to be entirely consistent with the clinical history and an alternative diagnostic method. The speed, sensitivity, and specificity of this method is relevant for the diagnosis of infection with IBDV.

Animals↗
PubMed1992

Foods predictive of nutrient intake in Chinese diet in Taiwan: I. Total calories, protein, fat and fatty acids.

Dietary consumption data obtained by food weighing for 539 households in Taiwan in 1980-1981 were used to search for foods predictive of nutrient intake. The average per capita nutrient intake in each household was calculated for total calories, protein, fat and fatty acids (saturated fatty acids, oleic acid and unsaturated fatty acids). Stepwise multiple regression analysis was carried out to reveal the relative importance of each of 405 food items in the dietary survey data for predicting nutrient intake. We found that as few as seven to 20 food items could account for a large proportion of the variability of macronutrient intake in this population. These lists of foods were the minimum needed to categorize an individual's nutrient intake for epidemiological studies in Taiwan. The types and amounts of cooking oils (important predictors of fat and calories) added to the dishes were found to vary from family to family, and should be considered in designing dietary questionnaires for Chinese in other societies.

Adolescent↗
PubMed1992

Foods predictive of nutrient intake in Chinese diet in Taiwan: II. Vitamin A, vitamin B1, vitamin B2, vitamin C and calcium.

Dietary consumption data obtained by food weighing for 539 households in Taiwan in 1980-1981 were used to search for predictor foods of individual intake of several vitamins and calcium. Stepwise multiple regression analysis was carried out on food items that were univariately and significantly associated with nutrient intakes, to screen for the important predictors. Less than ten foods were enough to explain more than 90% of the interperson variation for vitamin A, vitamin B1, and vitamin B2. For vitamin C and calcium, 20 food items could explain only 87% of the variation. Salt, brown sugar, and soy bean sauce were selected among calcium predictors. The information on foods predictive of nutrient intake is useful in designing food frequency questionnaires and materials for nutrition education. Although this paper provides such information for Chinese living in Taiwan, some issues described (such as the need to assess spices) may have been overlooked and could be generalized to populations using stir-frying as a major cooking method.

Ascorbic Acid↗
PubMed1992

Tumoral calcium pyrophosphate dihydrate deposition disease. Report of a case with a review of the literature.

In a 56-year-old female patient with a mass at the proximal end of the left third finger for 22 years, the lesion enlarged obviously during the last 4 years. Initial diagnosis was chondroma with malignant change, and disarticulation of the finger was performed. Pathological diagnosis was "secondary chondrosarcoma". Microscopically, the mass contained a large amount of amorphous basophilic phosphate deposits surrounded by fibrous capsule. The pyrophosphate deposits consisted of birefringent needle shaped or rhomboid crystals which can be identified by polarizing microscope. It can be distinguished as tumoral calcium pyrophosphate dihydrate deposition disease, differing from tophaceous pseudogout, tumoral calcinosis and chondrocalcinosis. Nine cases were collected from the literature and the clinical, radiological and pathological features were discussed.

Calcinosis↗
PubMed1992

Clinical aspects of a successful embryo cryopreservation programme from IVF cycles in Singapore General Hospital.

An analysis in November 1991 showed a successful cryopreservation programme between May 1989 and October 1991 in Singapore General Hospital. This programme has resulted in 9.1% more pregnancies in addition to those from conventional in-vitro fertilisation (IVF) methods, increasing pregnancy rates during the same period, from 27.8% per IVF cycle to 36.9% per cycle. The current policy is to transfer 3 fresh embryos in the IVF cycle and freeze the remainder using a modified Testart's method. Clinical factors that influence the success rate include the number of embryos transferred, stage of development of embryos and genital tract infections. Age of patient and grade of embryos did not seem to have affected pregnancy rates. Patients with anovulatory cycles enjoy similar pregnancy rates using a regulated cycle regime for frozen-thawed embryo transfer.

Adult↗
PubMed1992

A successful pregnancy from the oocyte donation programme in Singapore General Hospital.

A 41-year-old Chinese woman was seen in our centre in June 1989 with 5 years of premature menopause, requesting ovum donation. She was placed on cyclical hormonal therapy and put on the waiting list for ovum donation. Excess ova became available through one of our IVF patients and were fertilised with her husband's semen. Four pre-embryos resulted and these were cryopreserved using 1,2 propanediol. Embryo transfer in her second cycle of trying on 16 March 1990 of 2 pre-embryos was successful and a singleton pregnancy resulted. The pregnancy was supported with estradiol valerate and intramuscular progesterone till 17 weeks of gestation. The pregnancy went on uneventfully and she delivered a healthy baby boy by Caesarean section on 21 December 1990.

Adult↗
PubMed1991

Can ultrasonography reliably predict the occurrence of multiple pregnancies in gonadotrophin ovulation induction?

A retrospective study of 78 patients with 106 stimulated conception cycles after successful gonadotrophin ovulation induction was made to analyze the relationship between the sizes and numbers of ovarian follicles seen on ultrasound and the eventual number of conceptions that resulted in each cycle. Fifteen cycles (14.2%) resulted in spontaneous abortions. There were 58 singleton pregnancies (54.8%), 26 sets of twins (24.5%), 6 sets of triplets (5.6%) and 1 set of quadruplets (0.9%). In 86 cycles with the last scans performed shortly before the ovulating dose of HCG, 3 or more mature follicles were found in 50 (58%). These cycles resulted in 31 (62%) singletons, 16 (32%) twin pregnancies and 3 (6%) triplet pregnancies. Pregnancies resulted even when there were no 'mature' follicles seen on scan. No statistical correlation was found between plurality of pregnancy and size or number of follicles, or oestradiol excretion on the day the ovulating dose of HCG was given, although high-order multiple pregnancies were more likely if the oestrogen excretion was more than 200 ug/24 hours (p = 0.001). The dosage of HCG correlated inversely with the occurrence of multiple pregnancies (p = 0.02). In conclusion, neither oestrogens nor ultrasonography could accurately predict multiple conceptions in gonadotrophin stimulated cycles.

Estrogens↗
PubMed1990

Copper(II)-iminodiacetic acid chelating resin as a stationary phase in the immobilized metal ion affinity chromatography of some aromatic amines.

Styrene-divinylbenzene copolymer 60-80 mesh was used as the matrix and ground to a reasonable particle size in a colloid mill. Small and uniform particles (5-15 microns) can be obtained in a laboratory-made continuous acetone elutriation device. After elutriation the iminodiacetic acid (IDA) chelating resin was synthesized, and the infrared spectrum of the product indicated that the synthetic reaction is effective. The Cu(II)-modified IDA chelating resin was used as a stationary phase in high-performance immobilized metal ion affinity chromatography, packed into a column by the high-pressure slurry-packing technique. Methanol, to which ammonia was added as a competitive ligand, was used as the mobile phase for the separation of aromatic amines. The retention value of aromatic amines depends mainly on their basicity and molecular size. The results showed that some aromatic amines can be separated with the Cu(II)-IDA column.

Amines↗
PubMed1989

[Risk assessment of factors related to lactation of breast-feeding women by multichotomous logistic regression with stepwise procedure].

Based on Dubin and Pasternack's solution of parsimonious parameters, the authors proposed a procedure of stepwise selection of factors for establishing the Multichotomous logistic regression "best" model. Score statistic was used to select factors into model. Ratio of likelihood function was used to eliminate factors from model. The data of lactation from 129 breast-feeding women living in rural area have been analysed by the procedure. It showed that the first breast-feeding to the newborn of over 48 hours from her childbirth has negative effect while good appetite has positive effect on milk secretion. The epidemiological meaning of parameters estimated from the data was illustrated in detail.

Breast Feeding↗