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Biomedical subjects

L Y Hsu

Publications and source records attributed to L Y Hsu.

141 records · Page 8Linked to original sources
PubMedDate not supplied

Prenatal diagnosis of chromosome mosaicism.

The frequency of mosaicism and pseudomosaicism in the prenatal diagnosis of cytogenetic disorders is reported, based on 3000 pregnancies studied in our laboratory. Diagnosis of true mosaicism was only made when an abnormality was detected in two or more independent cultures established from an amniotic fluid sample. On this basis, 0.37 per cent of all cases were diagnosed as true mosaics. 1.07 per cent of all cases had pseudomosaicism involving more than one cell from the same culture with an identical abnormality. 4.13 per cent of cases had a single abnormal cell with an extra chromosome, loss of a sex chromosome (or part of a sex chromosome), or translocation. Details of the outcome and follow-up of cases is given. Particularly problematical were cases where multiple cells from one culture contained an abnormality which could have been clinically significant. A crude estimate of the extent to which true mosaicism might currently be misinterpreted as pseudomosaicism or entirely missed has been made, based on data from the U.S. survey (Hsu and Perlis , in press). It was concluded that even when two, and if necessary a third culture is extensively analysed with an average of 24 cells per culture counted, at least 4.5 per cent of cases of true mosaicism may be completely missed and at least 7 per cent could be misdiagnosed as pseudomosaicism . There is an urgent need for improved laboratory techniques which allow growth of a greater number of cell colonies and therefore a more broadly based analysis. Detailed long term follow-up of prenatally diagnosed mosaics is also essential for assessing the clinical significance of the laboratory findings.

Amniocentesis↗
PubMedDate not supplied

Maternal cell contamination of amniotic fluid cell cultures from two consecutive pregnancies complicated by fibroids.

The detection of maternal cells in amniocyte cultures is thought to be due to the outgrowth of cells from small fragments of maternal tissue removed by the amniocentesis needle. An unusual case is reported in which maternal cell contamination (MCC) was found in the cell cultures from a woman in two different amniocenteses from two consecutive pregnancies. Both pregnancies were complicated by the presence of fibroids and the fibroid tissue may have been the source of the maternal cells. A history of an amniocentesis in which there was MCC of cell cultures, or the detection of fibroids, may pose an additional risk for MCC attributable misdiagnosis in prenatal genetic studies.

Adult↗
PubMedDate not supplied

Pericentric inversion of the Y chromosome and prenatal diagnosis.

Pericentric inversion of the human Y chromosome has been estimated to occur with a frequency of 1-2 per thousand in various populations, and the results of this study, derived from over 12 000 prenatal diagnosis cases, is 1.15 per 1000. In these cases, it was concluded that there was no clinical significance because the fathers and male fetuses had the same pericentric inversion. Chromosome analysis of the father is advisable to determine whether or not the inversion is familial in order to be able to provide genetic counselling.

Chromosome Inversion↗
PubMedDate not supplied

Fungus allergens inside and outside the residences of atopic and control children.

Airborne fungi were collected during the peak fungus season, using the N6 Andersen sampler inside and outside the homes of 46 asthmatic children, 20 atopic children, and 26 nonatopic control children in the Taipei area. The geometric mean fungus concentrations of the asthmatic, atopic, and control groups were found to be 565, 411, and 608 colony-forming units (CFU) per m3 in the living rooms; 659, 464, and 602 CFU m3 in the bedrooms; and 547, 449, and 668 CFU m3 outdoors; respectively. Aspergillus, Cladosporium, and Penicillium were observed to be the most common microfungi, both indoors and outdoors. High correlations between indoor fungus levels (living rooms or bedrooms) and the corresponding outdoor levels were observed for these predominant genera. With regard to the Aspergillus species composition, A. flavus and A. niger were observed to be predominant and are, therefore, recommended to be included on a skin test panel. Moreover, among these three groups, there were statistically significant concentration differences for Cladosporium and Penicillium.

Adolescent↗
PubMedDate not supplied

Home dampness and childhood respiratory symptoms in a subtropical climate.

The association between measures of home dampness and symptoms of respiratory illness was evaluated in 1 340 8- to 12-y-old children in the Taipei area. The following were reported to occur in the homes: self-dampness (i.e., home considered damp by residents), 36.8% of the homes; "classified" dampness (i.e., presence of mold, water damage, or flooding), 72.3%; visible mold, 38.3%; stuffy odor, 33.9%; water damage, 47.8%; and flooding, 15.1%. Moreover, the prevalence of all respiratory symptoms was consistently higher in homes for which the occurrence of molds or dampness was reported. The adjusted odds ratios ranged from 1.37 (95% confidence interval: 1.03-1.83) for allergic rhinitis to 5.74 (95% confidence interval: 2.20-14.95) for cough. In addition, the observed high prevalence of home dampness/mold indicated that dampness in the home was very common in the subtropical region studied, and home dampness was a strong predictor of respiratory symptoms.

Age Factors↗
PubMedDate not supplied

Airborne fungus allergen in association with residential characteristics in atopic and control children in a subtropical region.

Airborne fungi were collected during the summer and winter seasons. A N6 Andersen sampler was used inside and outside the homes of 46 asthmatic children, 20 atopic children, and 26 nonatopic control children in the Taipei area. In addition, host and house characteristics were obtained by questionnaire. The indoor fungus concentrations of asthmatic and control groups were higher than those in atopic groups in summer, but there were no differences in total fungus concentrations among three groups in winter. Concentration differences among these three groups also occurred for Cladosporium and Penicillium in summer and for Aspergillus, Cladosporium, Penicillium, and yeast in the winter. Moreover, it was demonstrated that no differences in fungus concentration were observed between damp and dry homes. Penicillium concentrations appeared to be related to home dampness. Home dampness was associated with allergic symptoms in children with asthma and rhinitis. An association was also observed between the occurrence of Cladosporium and history of asthma.

Allergens↗
PubMedDate not supplied

Detection of mosaicism in amniotic fluid cultures: a CYTO2000 collaborative study.

PURPOSE: To evaluate the assumptions on which the American College of Medical Genetics (ACMG) Standards and Guidelines for detecting mosaicism in amniotic fluid cultures are based. METHODS: Data from 653 cases of amniotic fluid mosaicism were collected from 26 laboratories. A chi-square goodness-of-fit test was used to compare the observed number of mosaic cases with the expected number based on binomial distribution theory. RESULTS: Comparison of observed data from the in situ colony cases with the expected distribution of cases detected based on the binomial distribution did not reveal a significant difference (P = 0.525). CONCLUSIONS: The empirical data fit the binomial distribution. Therefore, binomial theory can be used as an initial discussion point for determining whether ACMG Standards and Guidelines are adequate for detecting mosaicism.

Amniotic Fluid↗
PubMedDate not supplied

Effects of exogenous androgen treatment on X-chromatin.

In studying a possible hormonal influence on X-chromatin frequency, buccal smears from two groups of women, one on androgen therapy and one not on androgen therapy, were compared. Both groups were nonmenstruating, renal dialysis patients, 41 to 69 years of age. For each patient the X-chromatin frequency was determined from 100 analyzable and intact buccal mucosa cells. In determining X-chromatin frequency, stringent selection criteria were used, and a selection ratio was derived by dividing by 100 the total number of cells that were counted in order to discover 100 analyzable and intact cells. Using the Guard's staining technique, no significant difference could be demonstrated in either the X-chromatin frequency or the selection ratio between the women receiving androgens and those not receiving them.

Adult↗