Biomedical subjects

P Yang

Publications and source records attributed to P Yang.

366 records · Page 21Linked to original sources

PubMedDate not supplied

Atypical glomus tumor in the mediastinum: a case report with immunohistochemical and ultrastructural studies.

A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small "glomoid" cells arranged in organoid and hemangiopericytomalike patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors.

Actin Cytoskeleton↗

PubMedDate not supplied

Physical and social impact of alpha 1-antitrypsin deficiency: results of a survey.

BACKGROUND: Emphysema associated with alpha 1-antitrypsin deficiency can impose serious impairment. OBJECTIVE: To gather information about the impact of severe alpha 1-antitrypsin deficiency. METHODS: Mail survey, descriptive statistics. RESULTS: We sent a survey to 1730 subscribers to a national newsletter, 850 of whom had previously stated they had alpha 1-antitrypsin deficiency. A total of 414 questionnaires were returned; 398 respondents said they had alpha 1-antitrypsin deficiency, and 300 said they had the PiZZ phenotype. Sixty-six respondents who said they had the disease did not know their phenotype. Among the 304 respondents with severe deficiency, the mean age at the time symptoms first appeared was 35.0 years, but the mean age when the disease was diagnosed was 41.3 years. Overall, 75.3% of respondents with severe deficiency reported at least one adverse effect: 44.4% retired early, and 19.1% changed to a physically easier job. The duration of diagnostic delay correlated with the degree of adverse psychosocial effects. CONCLUSIONS: Alpha 1-antitrypsin deficiency frequently escapes diagnosis despite many medical encounters. Affected individuals are often unaware of basic details of their disease. Many patients report adverse psychosocial effects. Delay in diagnosing this disease is associated with adverse psychosocial effects.

Adolescent↗

PubMedDate not supplied

Liquid chromatography/electrospray ionization/isotopic dilution mass spectrometry analysis of n-(phosphonomethyl) glycine and mass spectrometry analysis of aminomethyl phosphonic acid in environmental water and vegetation matrixes.

A liquid chromatography/electrospray/mass spectrometry (LC/ES/MS) method was developed for the analysis of glyphosate (n-phosphonomethyl glycine) and its metabolite, aminomethyl phosphonic acid (AMPA) using isotope-labelled glyphosate as a method surrogate. Optimized parameters were achieved to derivatize glyphosate and AMPA using 9-fluorenylmethyl chloroformate (FMOC-Cl) in borate buffer prior to a reversed-phase LC analysis. Method spike recovery data obtained using laboratory and real world sample matrixes indicated an excellent correlation between the recovery of the native and isotope-labelled glyphosate. Hence, the first performance-based, isotope dilution MS method with superior precision, accuracy, and data quality was developed for the analysis of glyphosate. There was, however, no observable correlation between the isotope-labelled glyphosate and AMPA. Thus, the use of this procedure for the accurate analysis of AMPA was not supported. Method detection limits established using standard U.S. Environmental Protection Agency protocol were 0.06 and 0.30 microg/L, respectively, for glyphosate and AMPA in water matrixes and 0.11 and 0.53 microg/g, respectively, in vegetation matrixes. Problems, solutions, and the method performance data related to the analysis of chlorine-treated drinking water samples are discussed. Applying this method to other environmental matrixes, e.g., soil, with minimum modifications is possible, assuring accurate, multimedia studies of glyphosate concentration in the environment and the delivery of useful multimedia information for regulatory applications.

Chromatography, Liquid↗

PubMedDate not supplied

Palate teratogenicity and embryotoxicity of cyclosporin A in mice.

Mice of the A/J and B10.A/SgSnJ strains were treated with 50 mg of cyclosporin A (CsA) per kg of body weight on day 12 of gestation. There were significantly more fetal resorptions in both the A/J and B10.A strain when treated with CsA than in controls treated with olive oil. A low frequency (7.6%) of isolated cleft palates were induced in the A/J strain, which was significantly greater than that observed in A/J mice treated with olive oil alone. No cleft palates were induced in B10.A, which suggests that any increase in susceptibility that was observed could not be attributed to H-2 linked genes.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Association between non-right-handedness and cleft lip with or without cleft palate in a Chinese population.

The etiology of non-syndromic cleft lip with or without cleft palate (CL +/- P) is unclear, although both familial and environmental factors are implicated. Because CL +/- P occurs at approximately the time of brain lateralization and is most often unilateral, developmental asymmetry effects have been postulated in CL +/- P etiology. Handedness is frequently used as an indicator of brain lateralization; therefore, several studies have examined the relationship between cleft laterality and handedness. However, these studies have had conflicting results. The present study investigated handedness in a Chinese sample of 211 non-syndromic CL +/- P surgical probands (ascertained in Shanghai for family studies of CL +/- P), 221 population-based but unmatched controls, and 272 first-degree relatives of the probands. Handedness was assessed by means of laterality quotients (LQ) calculated from questionnaire data. Mean LQ's were compared, as were various arbitrary definitions of handedness based on the LQ, for cases versus controls, males versus females, right-sided versus left-sided clefts, and cleft lip alone versus cleft lip plus cleft palate. CL +/- P cases had a significantly higher proportion of non-right-handedness (NRH) than controls, regardless of the definition of NRH (P values < or = .001). There were no statistically significant differences for any of the other comparisons. Familiarity of NRH was tested by comparing first-degree relatives of cases to controls; first-degree relatives were found to have a significantly higher proportion of NRH than controls, supporting familial effects in NRH. These results support the concept of a common etiology and/or developmental pathway for CL +/- P and handedness.

Case-Control Studies↗

PubMedDate not supplied

Identification of human immunodeficiency virus-infected individuals by delayed type hypersensitivity skin testing.

OBJECTIVE: To determine if more useful information could be derived from delayed type hypersensitivity skin testing of human immunodeficiency virus (HIV)-infected patients by measuring the amount of induration in response to skin testing in contrast to assessing for the presence of anergy. DESIGN: Prospective, double-blind trial. SETTING: Two HIV clinics. PATIENTS: A sample of 60 ambulatory, HIV-infected patients and 18 normal controls. INTERVENTIONS: Delayed type hypersensitivity skin testing with a panel of recall antigens. MAIN OUTCOME MEASURES: Anergy, total induration in response to the panel of antigens, and CD4 lymphocyte count. RESULTS: Anergy was present in only 28 of 60 (46.7 percent) HIV-infected subjects. A low skin test score (under 20 mm of total induration) was present in 43 of 60 (71.7 percent) HIV-infected subjects (p < 0.01 vs anergy). One control patient was anergic, while two had a low skin test score (p = NS). Among HIV-infected subjects, there was poor correlation between CD4 lymphocyte count and skin test score (R2 = 0.12). CONCLUSIONS: Skin testing by this method identifies more HIV-infected patients than does assessing the presence or absence of anergy.

Adult↗