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Biomedical subjects

S B Amini

Publications and source records attributed to S B Amini.

At least 37 records · Page 2Linked to original sources
PubMed1997

Neonatal morbidity after elective repeat cesarean section and trial of labor.

OBJECTIVE: To evaluate neonatal outcomes after an elective repeat cesarean section (ERCS) compared with a trial of labor (TOL). POPULATION AND METHOD: All mothers who underwent previous cesarean section and delivered singleton infants at term gestation were identified during a 1-year period. Neonatal outcomes were compared between infants delivered by ERCS (n = 497) and those delivered by TOL (n = 492), and between infants delivered by a successful (n = 336) and a failed (n = 156) TOL. A cohort of mothers and their term infants delivered by routine vaginal delivery were also identified. RESULTS: Infants delivered by ERCS had an increased rate of transient tachypnea compared with infants born by TOL (6% vs 3%). Compared with routine vaginal deliveries, the adjusted odds ratio of developing any respiratory problem after an ERCS was 2.3 (95% confidence interval [CI]: 1.4, 3.8), and for developing transient tachypnea was 2.6 (CI: 1.5, 4.5). In addition, two infants delivered by ERCS developed respiratory distress syndrome. Infants delivered after a TOL had increased rates of suspected and proven sepsis (5% vs 2% and 1% vs 0.1%, respectively). Compared with a successful TOL, the infants delivered by cesarean section after a failed TOL had more neonatal morbidity and had a longer hospital stay (4.8 +/- 2 vs 3.1 +/- 2 days). The odds ratio for developing any respiratory illness after a failed TOL was 2.1 (95% CI: 1.1, 4.1), for suspected sepsis was 4.8 (95% CI: 2.6, 9.0), and for proven sepsis was 19.3 (95% CI: 2.0, 187). Neonatal outcomes after a successful TOL were similar to routine vaginal births. CONCLUSION: Infants born by ERCS are at increased risk for developing respiratory problems compared with those born by TOL. However, TOL is associated with increased rates of suspected and proven sepsis. This appears to be limited to infants delivered by cesarean section after a failed TOL.

Cesarean Section, Repeat↗
PubMed1997

Identification of dysplasia in human colonic aberrant crypt foci.

Aberrant crypt foci (ACF) are grossly invisible putative premalignant lesions in the colon. As dysplasia is considered an important precursor of colon carcinoma, we wanted to determine the presence and severity of dysplasia in human ACF. Fifty ACF from 28 patients were embedded in paraffin, cut serially, and stained with hematoxylin and eosin. Multiple slides from each ACF were evaluated for dysplasia according to a defined set of criteria. Of 50 ACF, 3 (6%) contained focal areas with severe dysplasia, ie, carcinoma in situ, 4 (8%) contained focal areas with moderate dysplasia, and 20 (40%) contained focal areas with mild dysplasia. Twenty-three ACF (46%) contained no detectable dysplasia. In 15 of 27 ACF with dysplasia, less than 50% (eg, 4 of 28, 10 of 54, and 10 of 30 sections) of the sections cut and evaluated from each ACF demonstrated dysplasia. The presence of dysplasia in a large proportion of ACF supports the hypothesis that they may be precarcinomatous.

Adult↗
PubMed1996

CWR22: the first human prostate cancer xenograft with strongly androgen-dependent and relapsed strains both in vivo and in soft agar.

Most patients' prostate cancers respond to androgen deprivation but relapse after periods of several months to years. Only two prostate cancer xenografts, LNCaP and PC-346, have been reported to be responsive to androgen deprivation and to relapse subsequently. Both of these tumors shrink slightly, if at all, and relapse less than 5 weeks after androgen withdrawal. After androgen withdrawal, the human primary prostate cancer xenograft CWR22 regresses markedly, and prostate-specific antigen (PSA) falls up to 3000-fold in the blood of mice. PSA usually returns to normal. In some animals, the tumor relapses and is then designated CWR22R. In these animals, PSA starts to rise approximately 2-7 months, and tumor begins to grow 3-10 months after castration. Animals with CWR22 need to be euthanized because of large tumors 6-12 weeks after the transplantation of CWR22. Androgen withdrawal prolongs life approximately 3-4-fold.

Agar↗
PubMed1996

Births to teenagers: trends and obstetric outcomes.

OBJECTIVE: To compare the trends and obstetric outcomes of pregnancy in teenage women with those of adult women. METHODS: We analyzed a 19-year (1975-1993) computerized perinatal data base with data on 69,096 births collected prospectively from a single inner-city tertiary medical center. RESULTS: Of all the births, 1875, (2.7%) were to teenagers 12-15 years old and 17,359 (25.3%) were to teenagers 16-19 years old. Over the study period, the number and proportion of births to teenagers of both age groups declined (P < .001 in both cases). The proportions of teenagers 12-15 and 16-19 years old were highest among blacks (4.1% and 28.1%, respectively), followed by Hispanics (2.4%, 24.7%) and whites (1.6%, 23.1%). More than 95% of teenagers had no private health insurance coverage (staff), significantly higher than the 81.6% of mothers aged 20 years or older (P < .001). More than 8.1% of teenagers 12-15 years old had two or fewer prenatal care visits, significantly higher than 6.8% for teenagers 16-19 years old and 7.1% for adults (P < .001). The average gestational age and birth weight were significantly lower for teenagers 12-15 years old compared with those 16-19 years old and adults. Patients 16-19 years of age had longer gestational age and higher birth weight than the adults. The proportion of primary cesarean deliveries among teenagers 12-15 years old was 11.6%, significantly higher than 9.4% for those 16-19 years old and 10.2% for adults (P < .001). CONCLUSION: On average, females 16-19 years old had better obstetric outcomes than adults, whereas obstetric outcomes for those 12-15 years old were worse than for adults. Therefore, all teenagers should not be grouped together when their obstetric outcomes are compared with those of adults.

Adolescent↗
PubMed1996

A SAS macro for stepwise correlated binary regression.

Several regression methods have been proposed for the analysis of correlated binary data, but none deals with the selection of covariates when there exist a large number of potentially relevant covariates. We present a SAS macro based on a stepwise selection procedure for the analysis of correlated binary data. Using regression methods based on generalized estimating equations originally proposed by Liang and Zeger and extended by Prentice, we describe a score test for forward selection, a Wald's test for backward elimination, and a test for model adequacy based on generalized scores. The methodology and the accompanying computer macro program written in SAS IML are illustrated with data from a prospective study of functional decline in the activities of daily living in a group of elderly patients.

Activities of Daily Living↗
PubMed1996

Abdominal and vaginal radical hysterectomy among U.S. women aged 65 years and older.

Unlike most European and Asian countries, radical vaginal hysterectomy (RVH) is not performed often in the United States, especially among older women. To examine the changes in RVH over the years, trends in hospital stay, hospital charges, and patient survival, we studied women aged 65 years and older undergoing RVH and compared them with patients receiving radical abdominal hysterectomy (RAH). During the study period there were a total of 288 RVH surgeries compared with 4,835 RAH surgeries. There were no significant changes in the number or proportion of RVH patients over 8 years (p = .50, trend test). On the average, RVH patients were significantly older and had shorter hospital stays. Among patients without cancer, there were no significant differences in the age, race, or survival of patients having either RVH or RAH. Similar results were obtained for patients with cancer.

Age Factors↗
PubMed1996

Altered expression of CD44 in human prostate cancer during progression.

There is a great need for markers that distinguish slowly progressive from rapidly progressive prostate cancers in paraffin-embedded tissues. CD44, an adhesion molecule that has been useful for the prediction of prognosis in some other cancers, has not been described in prostate cancer. The expression of CD44 was investigated with the monoclonal antibody GKW.A3 in prostate cancer in formalin-fixed, paraffin-embedded tissue sections of (1) whole prostates from 50 patients with 74 prostate cancers; and (2) lymph node metastases from 14 patients. Sixty percent of primary prostate cancers expressed CD44 moderately to strongly. No metastases expressed CD44 moderately to strongly; only 14% of metastases expressed even low levels of immunohistochemically detectable CD44. There is a difference between primary and metastatic prostate cancer (P <.0006) in the expression of CD44 and an inverse correlation (P <.05) between histological differentiation (Gleason grade) and the expression of CD44. The magnitude of the differential expression of CD44 in primary and metastatic prostate cancers suggests it should be investigated as an indicator of prognosis in a large prospective study.

Disease Progression↗
PubMed1996

Expression of E-cadherin in primary and metastatic prostate cancer.

Immunohistochemical studies have suggested that E-cadherin may be a useful prognostic marker in prostate cancer. Previous studies have depended on cryostat sections of tissues selected grossly. Many prostate cancers, even when extensive, are not visible grossly; many others cannot be demarcated sharply grossly. The wide applicability of prognostic markers after total prostatectomy will depend upon methods that can be applied to tissue selected based upon the histopathological examination of the entire prostate. Our purpose was to investigate the possibility that E-cadherin could be demonstrated in paraffin-embedded whole prostates and metastatic prostate cancer. Microwaving in citrate buffer was the best of five methods tested for the demonstration of E-cadherin in paraffin-embedded prostate and was used to investigate 53 primary prostate cancers from 44 patients and lymph node metastases from 14 patients. Metastases of prostate cancer to lymph nodes expressed less (P = 0.008) E-cadherin than primary prostate cancers. The expression of E-cadherin correlated with the histopathological differentiation (Gleason grade) of primary prostate cancers (P = 0.03, Ptrend = 0.003). The use of monoclonal anti-human E-cadherin (HECD-1) with microwaving in citrate buffer followed by immunoperoxidase staining with heavy metal enhancement for the demonstration of E-cadherin in paraffin-embedded tissue will, for the first time, allow the use of archival tissue for prognostic studies of E-cadherin in prostate cancer and other tissue. Our results are consistent with the hypothesis that aggressive prostate cancers exhibit decreased expression of E-cadherin and demonstrate the feasibility of long-term prognostic studies of this molecule in the usually multiple prostate cancers found in whole, formalin-fixed, paraffin-embedded resected prostates.

Antibodies, Monoclonal↗
PubMed1995

Factors affecting fetal growth and body composition.

OBJECTIVE: Our purpose was to identify factors affecting fetal growth with birth weight and body composition. STUDY DESIGN: A total of 183 singleton infants had birth weights and estimates of body composition performed within 24 hours of birth. Independent variables included were (1) maternal height, weight, pregravid weight, weight gain, education, and parity, (2) paternal height and weight, and (3) neonatal sex and gestational age. Best-fit stepwise regression analysis was used to correlate the independent variables with birth weight, fat-free mass, and fat mass. RESULTS: Compared with females, males had greater birth weight (p = 0.009) and fat-free mass (p = 0.0001) but not fat mass (p = 0.32). The strongest predictors were gestational age with birth weight (R2 = 0.10), neonatal sex with fat-free mass (R2 = 0.08), and parity with fat mass (R2 = 0.08). By use of the significant independent variables we explained 29% of the variation in birth weight, 30% in fat-free mass, and 17% in fat mass. CONCLUSION: These data support the concept that various genetic and environmental factors may modify fetal growth by differentially affecting growth of fetal fat and fat-free mass.

Adipose Tissue↗
PubMed1995

Maternal carbohydrate metabolism and its relationship to fetal growth and body composition.

OBJECTIVE: Our purpose was to correlate maternal carbohydrate metabolism and parental morphometric measurements with neonatal birth weight, body composition, and placental weight. STUDY DESIGN: Sixteen singleton (six control and 10 abnormal glucose tolerance) infants had placental weight, birth weight, and estimates of body composition performed within 24 hours of birth. Independent variables considered were (1) maternal and paternal demographic and morphometric measures, (2) neonatal sex and gestational age, and (3) estimates of maternal carbohydrate metabolism, including basal hepatic glucose production, insulin response, and insulin sensitivity. All metabolic measurements were performed before conception and in early (12 to 14 weeks) and late (34 to 36 weeks) gestation. Best-fit stepwise regression analysis was used to relate the independent variables with placental weight, neonatal birth weight, fat-free mass, and fat mass. RESULTS: Insulin sensitivity in late gestation had the strongest correlation with placental weight (R2 = 0.28), neonatal birth weight (R2 = 0.28), and fat-free mass (R2 = 0.33). In contrast, insulin sensitivity before conception had the best correlation with neonatal fat mass (R2 = 0.15). Including all significant independent variables in the model improved the correlations for placental weight (R2 = 0.58), birth weight (R2 = 0.48), fat-free mass (R2 = 0.53), and fat mass (R2 = 0.46). CONCLUSION: Maternal insulin sensitivity had stronger correlations with fetoplacental growth in comparison with maternal demographic or morphometric factors.

Adipose Tissue↗
PubMed1995

Anthropometric estimation of neonatal body composition.

OBJECTIVE: Estimation of neonatal body composition can be useful in the understanding of fetal growth. However, body composition methods such as total body water and total body electric conductivity are expensive and not readily available. Our primary purpose was to develop an anthropometric model to estimate neonatal body composition and prospectively validate the model against total body electric conductivity and secondarily to compare our anthropometric model and a previously published anthropometric formula with total body electric conductivity. STUDY DESIGN: A total of 194 neonates had estimates of body composition according to total body electric conductivity (group 1). Parental morphometrics, gestational age, race, sex, parity, and neonatal measurements including birth weight, length, head circumference, and skinfolds (triceps, subscapular, flank, and thigh) were correlated with body fat by use of stepwise regression analysis. The model was validated in a second group of 65 neonates (group 2). RESULTS: There were no significant differences in any of the parental or neonatal measurements between groups 1 and 2. In group 1, 78% of the variance in body fat with the use of total body electric conductivity was explained by birth weight, length, and flank skinfold (R2 = 0.78, p = 0.0001). When prospectively validated by the subjects in group 2, the model had significant and stronger correlation (R2 = 0.84, p = 0.0001) with body fat estimated by total body electric conductivity as compared with the other anthropometric model (R2 = 0.54, p = 0.0001). There was no significant (p = 0.11) difference between our anthropometric estimate of body fat and total body electric conductivity. CONCLUSIONS: The anthropometric model developed can be used to reasonably predict neonatal body fat mass at birth.

Adipose Tissue↗
PubMed1995

Estimating body composition in late gestation: a new hydration constant for body density and total body water.

Twenty women underwent body density (DB) measurements using underwater weighing with correction of residual lung volume by nitrogen dilution and total body water (TBW) using isotope dilution of 18O to estimate body composition at 30 wk of gestation. DB and TBW were used as independent variables in the same equation. The hydration constant (HC) of fat-free mass (FFM) was estimated as 0.762; based on this HC, new body composition equations for both DB and TBW were derived. These equations were prospectively tested in an additional 20 women at 30 wk of gestation. No significant differences were detected between estimates of percent body fat (%F) using either the newly derived DB or TBW equations and estimates of %F using both DB and TBW. Ten of these forty women were evaluated postpartum. There was no significant difference in %F estimated by either TBW or DB compared with standard equations (hydration of FFM = 0.72) and %F using both DB and TBW. These results highlight the importance of either measuring both DB and TBW or using an appropriate hydration constant for FFM in estimating body composition during pregnancy or conditions associated with increased body water.

Adult↗
PubMed1994

Trends in an obstetric patient population: an eighteen-year study.

OBJECTIVE: Our goal was to evaluate various trends including gestational age, birth weight, and mode of delivery in an inner-city obstetric patient population delivered at a tertiary medical center. STUDY DESIGN: We used an 18-year computerized perinatal database collected prospectively since 1975 in an inner-city tertiary medical center. More than 63,500 deliveries from 1975 through 1992 were evaluated. Trends in gestational age, birth weight, and mode of delivery were investigated with Cox-Stuart, regression, and other trend analysis methods. RESULTS: The number of deliveries increased from 2682 in 1975 to 4740 in 1991, an increase of 77%. The median maternal age has increased from 20 years in 1975 to 23 years in 1992 (p < 0.001). Overall, the mean gestational age has declined monotonically from 39.2 +/- 2.84 weeks in 1975 to 38.3 +/- 3.17 weeks in 1992 (p = 0.057). While the median and lower percentiles of birth weight for singleton births have declined, the 75th and higher percentiles of birth weight have increased during 18 years. Overall, the proportion of preterm births (< 37 completed weeks gestational age) has increased from 3.3% in 1975 to 7.8% in 1991 (p < 0.001). During this period the proportion of low-birth-weight infants (< 2,500 gm) increased significantly from 12.7% to 17.3% (p < 0.001). The proportion of cesarean section deliveries for private patients has declined from 37% in 1975 to 25% in 1992 (p = 0.025), while this proportion has increased monotonically for staff patients from 10% to 17% during this period (p < 0.001). CONCLUSIONS: Considering the large size of the database and diverse background of the study population, we believe that these trends can provide a realistic characterization of an obstetric patient population for a large inner-city urban population.

Adolescent↗
PubMed1994

Carcinoembryonic antigen in human colonic aberrant crypt foci.

BACKGROUND/AIMS: Aberrant crypt foci are putative preneoplastic lesions that, by definition, are identified microscopically in whole-mount preparations of colonic mucosa. Because the identification of hexosaminidase as a marker for rat aberrant crypt foci in histological sections facilitated their characterization, a similar marker for human foci in histological sections was sought. METHODS: Human aberrant crypt foci were marked in whole-mount preparations, embedded in paraffin, and evaluated for their expression of carcinoembryonic antigen with two monoclonal antibodies. RESULTS: Elevated expression of carcinoembryonic antigen was detected in 39 of 42 (93%) aberrant crypt foci from 15 patients. The expression of carcinoembryonic antigen assisted in the evaluation of longitudinal sections of foci, where dysplasia is more readily detected in these small lesions. The expression of carcinoembryonic antigen was related to the sizes of the foci (P = 0.0085, generalized Fisher's Exact Test) but not to the presence or degree of dysplasia. CONCLUSIONS: The overexpression of immunohistochemically demonstrable carcinoembryonic antigen is, to date, the only described alteration in most of these putative precursors of human colon cancer that differs from the expression in contiguous, normal crypts at the histological level and thus facilitates the identification of aberrant crypts in histological sections for further characterization.

Adult↗
PubMed1994

An analysis of birth weight by gestational age using a computerized perinatal data base, 1975-1992.

OBJECTIVE: To develop birth weight-for-gestational age nomograms based on a computerized perinatal data base collected prospectively from 1975-1992. METHODS: Using information from over 60,000 singleton deliveries (January 1975 through October 1992) at the MetroHealth Medical Center in Cleveland, Ohio, standard curves for normal birth weights were computed. Nomograms were developed for the overall population and for subgroups determined by factors known to affect fetal growth, including sex, race, smoking status, and gestational diabetes. The nomograms included the tenth, 50th, and 90th percentiles of birth weights for 24-44 weeks' gestation. Gestational age was based on clinical obstetric estimates confirmed by Dubowitz assessment of the neonate. In addition, third-order regression models were developed to predict median birth weight using gestational age. These models were validated using delivery data for the months of November and December, 1992, which were not included in model development. RESULTS: The most significant predictors of median birth weight were the first-, second-, and third-order gestational ages, which explained over 80% of the total variation in birth weight. Other significant factors influencing birth weight included infant gender, maternal race, parity, smoking, and diabetes status. Among the marginally significant factors influencing birth weight were pay status and maternal age. In general, before 33 weeks' gestation, there were few differences in the birth weight percentiles of various groups except for those with diabetes; infants of diabetic women exhibited greater birth weights as early as 26 weeks' gestation. CONCLUSIONS: Considering the large size of the data base and the diverse background of the study population, we believe that these nomograms provide useful norms of birth weight for an indigent urban population. These norms enhance the obstetrician's and neonatologist's ability to identify true cases of retardation or acceleration of intrauterine growth. Simple mathematical models provide easy calculation of the median birth weights for 24-44 weeks while adjusting for many confounding factors.

Adult↗
PubMed1993

Reproducibility of the oral glucose tolerance test in pregnant women.

OBJECTIVE: The purpose of this study was to evaluate the reproducibility of the 3-hour oral glucose tolerance test during pregnancy and the potential factors associated with nonreproducible results. STUDY DESIGN: Thirty-eight women with a 1-hour glucose level > or 135 mg/dl had a 100 gm oral glucose tolerance test. During the test samples were obtained for glucose, insulin, cortisol, human placental lactogen, and norepinephrine levels. The oral glucose tolerance test was repeated 1 week later under similar metabolic conditions. RESULTS: The intraassay coefficient of variation in glucose from week 1 to week 2 was < 2%. There were no significant differences in the paired fasting 1-, 2-, or 3-hour glucose concentrations (p = 0.51 to 0.96) or the area under the glucose curve (p = 0.43) from week 1 to week 2, although the mean absolute difference in glucose values ranged from 4 (fasting) to 18 (3 hours) mg/dl. Oral glucose tolerance test results were classified as either normal or abnormal from week 1 to week 2; 16 normal/normal, 13 abnormal/abnormal, seven abnormal/normal, and two normal/abnormal. Norepinephrine (p = 0.03) and insulin (p = 0.05) were significantly greater in week 1 but not in week 2 in the abnormal/normal versus normal/normal and abnormal/abnormal groups. There were no significant differences in cortisol or human placental lactogen levels among groups at any time. CONCLUSIONS: The oral glucose tolerance test was not reproducible for diagnosis in 24% (nine of 38) of pregnant women. We speculate that maternal stress (increased norepinephrine) may have been a factor for the abnormal results in week 1 in the abnormal/normal group.

Adult↗
PubMed1993

Carbohydrate metabolism during pregnancy in control subjects and women with gestational diabetes.

The purpose of this study was to characterize carbohydrate metabolism associated with the development of gestational diabetes. Six control (Ctl) and ten women with gestational diabetes mellitus (GDM) were evaluated using an intravenous glucose tolerance test and hyperinsulinemic-euglycemic clamp with [6,6-2H2]glucose prior to conception (P) and at 12-14 (E), and 34-36 wk of gestation (L). There was an increase (P = 0.0001) in first-phase insulin response in Ctl (P 174 +/- 133, E 388 +/- 120, and L 587 +/- 303 microU/ml) and GDM (P 197 +/- 94, E 267 +/- 77, and L 376 +/- 162 microU/ml) but a significant (P = 0.02) lag in change in GDM with advancing gestation. Basal endogenous glucose production increased during gestation [Ctl: P 2.74 +/- 0.23, E 2.62 +/- 0.38, and L 3.14 +/- 0.36; GDM: P 2.68 +/- 0.51, E 2.78 +/- 0.45, and L 2.98 +/- 0.48 mg.kg fat-free mass (FFM)-1 x min-1; P = 0.02], but there was resistance to suppression by insulin infusion (P = 0.03) in late gestation (GDM: 0.61 +/- 0.44 vs. Ctl: 0.16 +/- 0.17 mg.kg FFM-1 x min-1). Insulin sensitivity decreased during gestation (Ctl: P 10.78 +/- 2.78, E 8.34 +/- 2.36, and L 4.75 +/- 1.22; GDM: P 7.49 +/- 2.13, E 7.40 +/- 1.45, and L 4.21 +/- 1.01 mg.kg FFM-1 x min-1; P = 0.0001) and was primarily decreased (P = 0.04) in GDM compared with Ctl from P through E. These findings closely resemble those of non-insulin-dependent, predominantly insulin-resistant diabetes, which is often a sequel of GDM.

Adult↗