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Biomedical subjects

A Gerson

Publications and source records attributed to A Gerson.

At least 19 recordsLinked to original sources
PubMed2005

Expression of D-type cyclins in colon cancer and in cell lines from colon carcinomas.

Cyclins D1, D2 and D3 play important roles in cell proliferation and differentiation. Although their abnormal expression has been linked to cancer development and progression in a number of tissues, the expression of cyclin D2 and D3 proteins in colon cancer has not yet been characterised. In this study, we examined cyclin D1, D2 and D3 protein expression by Western blot analysis in tumour and adjacent normal colon tissues of 57 patients. In addition, we examined D-type cyclins protein expression in HT29 and LoVo39 cell lines from colon carcinomas, as a function of induced proliferation and differentiation. In both cell lines, the expression of the three D-type cyclins increased as a result of induced proliferation, whereas the expression of cyclin D3 increased as a result of induced differentiation. In colon tumours, cyclin D1 was overexpressed in 44%, cyclin D2 was overexpressed in 53% and cyclin D3 was overexpressed in 35% of the cases. We also found that in 16% of the cases, cyclin D3 protein expression was reduced in the tumour, as compared to the adjacent normal tissue. Examination of D-type cyclin protein overexpression in relation to the TNM stage of the tumours revealed that overexpression of cyclins D1 and/or D2, but not cyclin D3, is linked to colon carcinogenesis and that overexpression of cyclin D2 may be related to a higher TNM stage of the tumour.

Aged↗
PubMed1999

Monoamniotic twins: case series and proposal for antenatal management.

OBJECTIVE: To present a case series of antenatally suspected monoamniotic twin gestations managed by a similar set of guidelines. METHODS: Eight women with antenatally suspected monoamniotic twins were identified between 1994 and 1996 in a single perinatal referral area. All were diagnosed sonographically. Management included serial ultrasound studies, frequent nonstress testing, and weekly steroid therapy. Elective cesarean delivery was recommended at 32 weeks unless obstetrically indicated at an earlier age. RESULTS: Monochorionic monoamniotic twins were confirmed at delivery in six women, and one had a pseudomonoamniotic twin. One woman was found to have a monochorionic diamniotic pregnancy at delivery. Of the eight women, three were delivered by elective cesarean at 32 weeks, including the falsely diagnosed case. Three were delivered before 32 weeks because of nonreassuring fetal testing. One was delivered at 25 weeks secondary to hemolysis, elevated liver enzymes, low platelets, and disseminated intravascular coagulation. One was delivered at 33 weeks, after declining elective delivery at 32 weeks, because of death of one twin and nonreassuring testing of the other twin. Morbidity among the live-born infants included severe bronchopulmonary dysplasia (25-week twins), large-bowel perforation (30-week infant), and respiratory distress syndrome and mild bronchopulmonary dysplasia (one 32-week pair). CONCLUSION: Monoamniotic twin pregnancies can be diagnosed reliably by ultrasound alone in most cases. Frequent antenatal testing may show signs of cord compression that may prompt delivery but will not prevent sudden fetal death. Fetal death can occur at greater than 32 weeks' gestation despite intensive fetal surveillance. Elective preterm delivery could be considered to eliminate the uncertain risk of fetal death.

Adult↗
PubMed1997

Amniotic fluid index in twin gestation.

This study was performed to describe a methodology for a two-pocket amniotic fluid index (AFI) for each fetus of a twin gestation. Data included 216 pairs of measurements that were analyzed to yield regressions (curves) for all observations, as well as for the larger and smaller AFI of each observation on a particular set of twins. The twin AFI increased non-linearly until week 27. From week 27 to week 36, decreasing linear trends were found. Measures of intrasonographer, intersonographer, within-mother and between-mothers variation are reported. The estimates of variation were used to plot confidence limits for all three curves.

Adult↗
PubMed1996

Pregnancy and warm autoantibodies: a case report.

The presence of the maternal warm antibody in pregnancy should not be ignored. As there is risk of both maternal and fetal anemia, both patients need to be followed for the development of such. Serial complete blood counts in the mother and treatment if significant fetal anemia develops should be considered. Serial amniocentesis and nonstress testing should be part of any management plan in the presence of a maternal warm antibody.

Adult↗
PubMed1995

Interrelationship of MMPI-2 validity scales in personal injury claims.

A sample of MMPI-2s of worker's compensation and personal injury cases (N = 289) was gathered to examine the relationship of various indicators of exaggeration. Intercorrelations of the F, F-K, the MMPI Dissimulation Scale-revised (Ds-r), total of obvious minus subtle scales (O-S), Fake Bad Scale (FBS), VRIN, and TRIN were computed and the relative sensitivity of each score calculated using various cut-offs. Factor analysis suggests that malingering may take the form of inconsistent responding as well as symptom exaggeration. Patients evaluated at the request of plaintiff attorneys showed a seemingly greater degree of symptom exaggeration and inconsistent responding than did those referred by defense counsel.

Accidents, Occupational↗
PubMed1990

Safety and efficacy of long-term tocolysis with indomethacin.

Indomethacin was utilized in 24 pregnancies (31 exposed fetuses) in preterm labor who labored despite intravenous tocolysis. The mean gestational age at the start of indomethacin therapy was 25.1 weeks (+/- 4.4), mean duration of indomethacin therapy was 43.9 days (+/- 31.4), mean gestational age at delivery 33.1 weeks (+/- 3.7). Neonatal follow-up revealed the same incidence of complications in these indomethacin-exposed infants, when they were compared with all other infants born in the same time period and exposed to intravenous tocolytics only when matched for gestational age at delivery.

Apgar Score↗
PubMed1988

Umbilical arterial systolic/diastolic values in normal twin gestation.

Linear regression analysis was used to describe the relationship of umbilical arterial systolic/diastolic values to gestational age in 65 twin gestations. This relationship (y = 6.18 - 0.11x) was then compared with a previously described regression for singleton pregnancies using a multiple regression model. This comparison revealed that the relationship between the systolic/diastolic ratio and gestational age is the same in singleton and twin gestations.

Diastole↗
PubMed1978

Verification of the optimal probabilistic basis of aural processing in pitch of complex tones.

Periodicity pitch for complex tones has been quantitatively accounted for by a two-stage process of Fourier-frequency analysis subject to random errors and significant nonlinearities, followed by an harmonic pattern recognizer that makes an optimum probabilistic estimate of the fundamental period of musical and speech sounds. The theory predicts that periodicity pitch is a multimodal probabilistic function of a given stimulus. A clear and empirically supported distinction is made between limitations on the pitch mechanism caused by the stochastic nature of aural frequency representation and by the deterministic resolution bandwidths of aural frequency analysis. This model was developed earlier [J. L. Goldstein, J. Acoust. Soc. Am 54, 1496-1516 (1973)] to account for probabilistic data on pitch errors [A. J. M. Houtsma and J. L. Goldstein, J. Acoust. Soc. Am. 51, 520 (1972)] measured with periodic stimuli comprising two successive harmonics. This paper presents new predictions by the theory that were calculated, with computer simulation where needed, for known probabilistic pitch data from stimuli comprising three to six successive harmonics. Predicted pitch errors increase with increasing errors in estimating the frequencies of stimulus harmonics and decrease as more harmonics are added to the stimulus. Optimum processor theory fully accounts for the multicomponent pitch data on the basis of similar errors in estimating component stimulus frequencies as reported earlier, thus providing further evidence for the optimum probabilistic basis of aural signal processing in pitch of complex tones.

Auditory Cortex↗
PubMed1978

Evidence for a general template in central optimal processing for pitch of complex tones.

Optimum processor theory successfully accounts for earlier pitch data by including the constraint that component tones in a complex stimulus are estimated as successive harmonics. This constraint gives the paradoxical prediction that a periodic complex tone comprising nonsuccessive harmonics cannot evoke periodicity pitch corresponding to its period. Most published data from pitch-shift experiments imply the necessity for this constraint. New periodicity pitch experiments on pitch shift and musical interval recognition were performed which prove that the theoretical constraint is not generally true. New and old data are reconciled by replacing the maximum likelihood estimation of the theory with maximum posterior probability estimation and removing the successive harmonic constraint. Periodicity pitch is estimated by optimizing the match between the aurally measured frequencies of stimulus components and a general harmonic template over some a priori expected pitch range. The new, more general, formulation reduces in many experimental situations to the successive harmonic constraint as a special case.

Auditory Cortex↗