Biomedical subjects

A E Barón

Publications and source records attributed to A E Barón.

At least 19 recordsLinked to original sources

PubMed2002

The effect of total body water on the relationship between alcohol consumption and carbohydrate-deficient transferrin.

BACKGROUND: Clinicians agree that alcoholism commonly is overlooked in their patients, and that treating the symptoms without directing therapy to the underlying cause at best delays an inevitable decline in the patient's general health and well-being. The current analysis focused on carbohydrate-deficient transferrin (CDT), a promising biological marker of dangerous alcohol consumption. METHODS: Included in our study were men (730) and women (613) from study sites in Canada, Brazil, and Japan. All subjects were participants in the WHO/ISBRA Study on State and Trait Markers of Alcoholism, who completed an extensive demographic, medical, and behavioral survey and provided blood samples for determination of CDT levels. ANOVA and chi2 test for equality were used to examine the effect of total body water (TBW) on the alcohol consumption/CDT relationship. To examine whether accounting for differences in TBW improved the diagnostic properties of CDT when used as a state marker for alcohol consumption, odds ratios were calculated for men and women separately. RESULTS: Our results show that accounting for individual differences in TBW significantly influenced the alcohol consumption/CDT dose-response relationship. The effect of TBW was different for men compared with women. When we used a consumption cutoff value of 40 g/day and the CDTect recommended cutoffs (20 for men; 27 for women), adjusting for differences in TBW significantly increased diagnostic performance of CDT in men but not women. CONCLUSIONS: The dependence of CDT measures on body water content needs to be taken into account to maximize the performance of CDT as an effective state marker of alcohol consumption in males.

Adolescent↗

PubMed2001

Normal bone mineral density after treatment for childhood acute lymphoblastic leukemia diagnosed between 1991 and 1998.

OBJECTIVE: We investigated whether previous reports of reduced bone mineral density after management for childhood acute lymphoblastic leukemia (chALL) were confirmed in a more recently treated cohort. STUDY DESIGN: In a cross-sectional study 75 subjects who were given the diagnosis of chALL between January 1, 1991, and December 31, 1997 (69% standard, 31% high risk), at Denver Children's Hospital and who were 11 to 82 months post-diagnosis with no history of relapse, secondary malignancy, or transplant underwent whole body areal bone mineral densitometry (BMD(A) expressed as age- and sex-standardized z scores), a food frequency questionnaire, and a weight-bearing activity survey. RESULTS: Overall, the mean whole body BMD(A) z score was normal (+0.22 +/- 0.96). A significant positive association was found with whole body BMD(A) z score and years elapsed since the beginning of maintenance (linear regression coefficient = +0.2 Deltaz score/year; 95% CI = 0.09 to 0.3) after adjustment was done for risk status/age category, history of cranial radiation, and total days hospitalized. No association was found with high risk/older age at diagnosis, nutrient intake, chemotherapy dosage, or weight-bearing activity. CONCLUSION: Contrary to previous reports in which cranial radiation and longer hospitalizations were prominent components of therapy, our study suggests that more recently treated patients with chALL do not have persistent abnormalities of bone mineral density after completion of therapy.

Biomarkers↗

PubMed2001

Thromboembolic disease: variability of interobserver agreement in the interpretation of CT venography with CT pulmonary angiography.

OBJECTIVE: The objective of this study was to determine interobserver agreement in the diagnosis of acute deep venous thrombosis on CT venography performed in addition to CT pulmonary angiography. SUBJECTS AND METHODS: One hundred forty-six CT venograms of 144 patients (mean age, 61.74 years) clinically suspected of having pulmonary embolism were analyzed prospectively and independently by two experienced thoracic and body imaging radiologists and later by consensus of the two radiologists. The CT venography protocol consisted of 5-mm-thick axial images at 20-mm intervals from the popliteal fossa to the renal veins. Images were acquired 3-4 min after the start of 100-150 mL of undiluted contrast medium administration at 4 mL/sec. Thirteen venous segments were analyzed in each patient. There were 1586 analyzable venous segments. RESULTS: Interobserver agreement, with the patient as the unit of analysis, was moderately good (kappa, 0.59; 95% confidence interval [CI], 0.39-0.78). Kappa values were similar for CT venography studies performed with 150 mL of contrast medium and 4-min delay (kappa, 0.62; 95% CI, 0.30-0.88) and with 3-min delay and 100 mL of contrast medium (kappa, 0.56; 95% CI, 0.32-0.80). Interobserver disagreement occurred in 17 (12%) of 146 CT venography studies. Findings of 11 CT venography studies were interpreted as negative, and six were interpreted as positive after consensus interpretation. CONCLUSION: Interobserver agreement for deep venous thrombosis with CT venography is moderately good.

Adult↗

PubMed2000

Linear discriminant models for unbalanced longitudinal data.

This paper discusses statistical methods for the classification of observations into one of two or more groups based on longitudinal observations. Measurements on subjects in longitudinal medical studies are often collected at different times and on a different number of occasions. Classical multivariate methods for linear discriminant analysis are difficult to apply to repeated measurements due to the highly unbalanced structure observed in these data. Linear models for the analysis of longitudinal data proposed by Laird and Ware and non-linear models proposed by Lindstrom and Bates can be used to estimate population parameters for a discriminant model that classifies individuals into distinct predefined groups or populations. An example is presented using data from a study in 150 pregnant women in Santiago, Chile, in order to predict normal versus abnormal pregnancy outcomes.

Abortion, Spontaneous↗

PubMed2000

Prediction of cervical intraepithelial neoplasia grade 2-3 using risk assessment and human papillomavirus testing in women with atypia on papanicolaou smears.

OBJECTIVE: To determine whether human papillomavirus (HPV) DNA testing and risk assessment can predict cervical intraepithelial neoplasia (CIN) 2-3 on biopsies in women with atypia on Papanicolaou smears. METHODS: One hundred ninety-five consenting women were referred for colposcopy because of atypia on Papanicolaou smears between September 1997 and April 1999. Before colposcopy, women completed risk assessments and had cervical swabs collected for HPV testing using the Hybrid Capture-II assay (Digene Corporation, Silver Spring, MD). Associations of demographic and clinical variables were assessed by chi(2) analysis, and logistic regression was used to assess factors associated with CIN 2-3. The cost-effectiveness of routine colposcopy versus reflex HPV testing by either conventional or liquid-based Papanicolaou smear media was compared. RESULTS: Cervical intraepithelial neoplasia was diagnosed in 70 of 195 women (35.9%), 55 (28.2%) with CIN 1 and 15 (7.7%) with CIN 2-3. High-risk HPV types were detected in 31.3% of all subjects, 36.4% of those with CIN 1, and 93.3% of those with CIN 2-3. By logistic regression, CIN 2-3 was associated only with detection of high-risk HPV (odds ratio 110.08, 95% confidence interval 8.35, 999. 00). The sensitivity of high-risk HPV for detecting CIN 2-3 was 93. 3%, specificity 73.9%, positive predictive value 23.0%, and negative predictive value 99.3%. The cost of reflex HPV testing using conventional smear or liquid-based media was less than routine colposcopy ($4809 and $4308, respectively, versus $4875 per case detected). CONCLUSIONS: Triage based on HPV testing would result in referral of approximately 31% of patients to colposcopy and appears to be a sensitive and cost-effective alternative to colposcopy.

Adult↗

PubMed2000

Thromboembolic disease: comparison of combined CT pulmonary angiography and venography with bilateral leg sonography in 70 patients.

OBJECTIVE: The purpose of this study was to compare combined CT pulmonary angiography and venography with leg sonography for accuracy and relative efficacy in diagnosis of deep venous thrombosis from the popliteal vein to the common femoral vein. SUBJECTS AND METHODS: Seventy consecutive patients with clinically suspected pulmonary embolism underwent both combined CT pulmonary angiography and venography and bilateral leg sonography within 24 hr. CT venograms were analyzed independently in a blinded fashion for quality of venous opacification and patency by two observers. CT venography was compared with sonography for femoropopliteal vein thrombosis, and the final assessment based on multiple subjective and objective clinical and imaging criteria was recorded in three categories: 1, CT venography better than sonography; 2, CT venography equivalent to sonography; and 3, sonography better than CT venography. RESULTS: Sixty-eight patients (97%) had a satisfactory or good quality CT venography examination. Two CT venography studies had false-positive findings due to flow artifacts. Both CT venography and sonography had positive findings for deep venous thrombosis in five patients, and both had negative findings in 63 patients (100% sensitivity, 97% specificity, 100% negative predictive value, and 71% positive predictive value). CT venography was better and more efficacious than sonography (category 1) in 25 patients (36%). CT venography was equivalent to sonography (category 2) in 26 patients (37%), and sonography was better than CT venography (category 3) in 19 patients (27%). CONCLUSION: Compared with sonography, CT venography in addition to CT pulmonary angiography is a relatively accurate method for evaluation of femoropopliteal venous thrombosis. Combined CT pulmonary angiography and CT venography may be more efficacious than sonography or two separate examinations in selected patients.

Adult↗

PubMed2000

Platelet adenylyl cyclase activity as a trait marker of alcohol dependence. WHO/ISBRA Collaborative Study Investigators. International Society for Biomedical Research on Alcoholism.

BACKGROUND: There is compelling evidence that genetic factors play a major role in the development of alcohol dependence. Platelet adenylyl cyclase (AC) activity has been proposed as a biochemical marker for differentiating alcohol-dependent and nondependent subjects, but the sensitivity and specificity of this marker have not been ascertained. The objective of this study was to determine the sensitivity and specificity of platelet AC activity in identifying alcohol-dependent subjects and to ascertain the effect of medical/ psychiatric variables, drinking and smoking history, and age and body weight on AC activity. METHODS: The cross-sectional study was conducted from 1995 to 1998. Participants were 210 Australian White men who were community volunteers and alcohol treatment inpatients in Sydney, Australia. There were 41 nondrinkers, 140 drinkers, and 29 men who were entering alcohol treatment. The main outcome measure was platelet AC activity. Classification variables were plasma ethanol, gamma-glutamyltransferase, aspartate aminotransferase, serum carbohydrate-deficient transferrin (CDT), and urinary 5-hydroxytryptophol/5-hydroxyindoleacetic acid (5-HTOL/5-HIAA) levels, and World Health Organization/International Society for Biomedical Research on Alcoholism Interview Schedule variables, which included alcohol use and dependence criteria. RESULTS: Among subjects who reported abstinence for at least 4 days, both cesium fluoride (CsF)- and forskolin-stimulated platelet AC activities were significantly lower in those with a lifetime history of alcohol dependence compared with those with no such history (p < 0.005 and p < 0.05, respectively). The sensitivity and specificity of CsF-stimulated AC activity to discriminate individuals with a lifetime history of alcohol dependence were 75% and 79%, respectively. Similar values for sensitivity and specificity for CsF-stimulated AC activity were calculated when discriminating current alcohol dependence in the subjects in our sample. Irrespective of the history of alcohol dependence, persons who had consumed alcohol recently (within the last 3-4 days) showed significantly higher mean basal, CsF-stimulated, and forskolin-stimulated AC activity (p < 0.001), as did those who had elevated 5-HTOL/5-HIAA ratios or CDT levels, indicative of recent (heavy) drinking. The "normalization" of platelet AC activity to baseline levels after an individual stops drinking may be related to the generation of new platelets during the abstinence period. Conduct disorder and antisocial personality disorder were not associated with low AC activity, but low forskolin-stimulated AC activity was associated with major depression. CONCLUSIONS: We found that CsF- and forskolin-stimulated platelet AC activity discriminates between subjects with and without alcohol dependence in a population of subjects who had not consumed significant quantities of ethanol recently. Recent alcohol consumption is a confounding variable that can alter the measured levels of AC activity. Forskolin-stimulated platelet AC activity also may be influenced by a history of major depression.

Adenylyl Cyclases↗

PubMed1999

Cognitive functioning and impairment among rural elderly Hispanics and non-Hispanic whites as assessed by the Mini-Mental State Examination.

We conducted a cross-sectional study to determine the distribution of cognitive functioning as measured by the Mini-Mental State Examination (MMSE) among a sample of Hispanic and non-Hispanic White (NHW) residents from two counties in rural, southern Colorado. Residents aged 60 years and older (N = 1,360) were administered the full MMSE, a sociodemographic and medical interview. Protocols were developed to administer the MMSE equitably in both ethnic groups. Younger Hispanics tended to be categorized as severely impaired more than similarly aged NHWs (OR at age 70 = 4.14), however, older Hispanics and NHWs performed similarly after adjusting for education and gender (OR at age 90 = 1.00). The use of a modified MMSE scale that removed the ethnic bias demonstrated that NHWs and Hispanics had similar levels of severe impairment after full adjustment (OR = 0.93). Given the widespread use of the MMSE, these findings indicate the need for further validation of this instrument.

Aged↗

PubMed1998

High-dose chemotherapy with autologous hematopoietic progenitor-cell support as part of combined modality therapy in patients with inflammatory breast cancer.

PURPOSE: To evaluate the feasibility of high-dose chemotherapy (HDC) with autologous hematopoietic progenitor-cell support (AHPCS) as part of combined modality therapy (CMT) in patients with inflammatory breast cancer (IBC). PATIENTS AND METHODS: From April 1993 to March 1997, 30 patients with IBC were treated at our program. Twenty-three patients received neoadjuvant chemotherapy (NAC) before HDC; 18 patients also received adjuvant chemotherapy following surgery, but before HDC. All patients received HDC with high-dose cyclophosphamide, cisplatin, and carmustine (BCNU) with AHPCS. Every patient underwent surgery either before (27 patients) or after (three patients) HDC. Patients received radiotherapy after HDC in addition to tamoxifen if their tumors were estrogen receptor-positive. RESULTS: Thirteen patients experienced grade 3 or 4 nonhematologic noninfectious toxicities. In 12 patients (40%), this represented drug-induced lung injury, which in all cases responded to a 10-week course of corticosteroids. The only treatment-related death was secondary to hemolytic-uremic syndrome (HUS). Another patient suffered grade 4 CNS toxicity, which was completely reversible. All patients engrafted promptly. Eight patients relapsed, five of whom had a poor pathologic response to NAC. Relapses were local (five patients), local plus systemic (one), or systemic only (two). Median follow-up time from diagnosis and HDC is 23.5 (range, 7 to 49) and 19 (range, 4 to 44) months, respectively. Twenty-one patients (70%; 95% confidence interval [CI], 51% to 86%) remain alive and free of disease 4 to 44 months after HDC. Median disease-free survival (DFS) and overall survival have not yet been reached. CONCLUSION: HDC as part of CMT is feasible in patients with IBC. The toxicity of this treatment program is significant, but tolerable. Despite the short follow-up duration, the promising DFS observed in this group of patients warrants randomized studies that include a HDC-containing arm in patients with IBC.

Adenocarcinoma↗

PubMed1998

Effects of abstinence and family history for alcoholism on platelet adenylyl cyclase activity.

Platelet adenylyl cyclase (AC) activity was measured in 32 alcohol-dependent subjects and 27 control subjects who were categorized as either family history-positive (FHP) or family history-negative (FHN) for alcoholism. The interview and blood sample collections were performed shortly after cessation of heavy drinking in the alcoholic group, and repeat blood samples were obtained at the end of the first and second weeks of monitored abstinence. Control subjects received the same interview and provided blood samples at the time of the interview. When subjects were not segregated for FHP or FHN status, there were no statistically significant differences in basal, cesium fluoride (CsF)-, or forskolin-stimulated mean AC activities between the controls and the alcoholics, at study entry or with 1 or 2 weeks of abstinence. On the other hand, over the 2-week course of sobriety from heavy drinking, the CsF-stimulated AC activity of FHP alcohol-dependent subjects decreased significantly (p = 0.03). FHP alcohol-dependent subjects after 2 weeks of sobriety had significantly lower mean CsF-stimulated AC activity than FHN controls (p = 0.04), whereas the FHN alcoholic subjects' CsF-stimulated AC activity did not differ significantly from FHN controls at this point in time. When all subjects were pooled and then categorized as either FHP or FHN, there was a significant difference in mean CsF-stimulated AC activity (p = 0.02) between the FHP and FHN subject groups. Genetic factors and abstinence appear to have roles in determining low platelet AC activity in alcoholic and nonalcoholic subjects. CsF-stimulated platelet AC activity, in particular, appears to act as a trait marker for a genetic vulnerability to developing alcoholism, but recent heavy drinking in male alcoholics is a factor that can mask differences between FHP and FHN subjects.

Adenylyl Cyclases↗

PubMed1997

Treatment of hepatic venocclusive disease with recombinant human tissue plasminogen activator and heparin in 42 marrow transplant patients.

The purpose of this report is to review the Fred Hutchinson Cancer Research Center experience of treating patients with venocclusive disease of the liver (VOD) after marrow transplantation using recombinant human tissue plasminogen activator (rh-tPA) and heparin. The charts of 42 patients who had received rh-tPA and heparin for the treatment of VOD between February 1991 and December 1995 were reviewed. Response to rh-tPA and heparin was defined as a reduction in total serum bilirubin by 50% within 10 days of starting treatment. Total serum bilirubin, percent weight gain, and serum creatinine before, after, and at the start of rh-tPA and heparin were examined to determine whether these laboratory values distinguished patients who responded to treatment from those who did not. We also evaluated whether evidence of multiorgan failure (requirement for supplemental oxygen, requirement for hemodialysis, requirement for mechanical ventilation) or whether the calculated probability of a fatal outcome from VOD could discriminate responders from nonresponders. In addition, the incidence and outcome of bleeding as a major complication of thrombolytic therapy was examined. Twelve patients responded to rh-tPA and heparin and 30 patients did not. There were no statistically significant differences between responders and nonresponders in the day treatment was started, dose of rh-tPA, total serum billirubin, and percent weight gain before, after, or at the start of treatment, or the calculated probability of dying from VOD on the day treatment with rh-tPA and heparin was begun. More nonresponding patients required dialysis or mechanical ventilation (11 of 30) before or at the start of rh-tPA and heparin than responding patients (0 of 12), P = .0183. Serum creatinine was greater at the start of treatment in nonresponding patients (1.9 +/- 1.3 mg/dL) than in responding patients (1.1 +/- 0.4 mg/dL), P = .0794. Ten patients had severe bleeding episodes, which resulted in death in three patients and may have contributed to death in an additional three patients. Treatment for VOD using rh-tPA and heparin was successful in 29% of patients but was associated with a significant risk of life-threatening hemorrhage. Requirement for supplemental oxygen, dialysis, or mechanical ventilation before the start of treatment were prognostic indicators of no response to thrombolytic therapy. We do not recommend treatment using tPA and heparin in patients with severe VOD who have already developed multiorgan dysfunction.

Adolescent↗

PubMed1997

High-dose chemotherapy with autologous peripheral blood progenitor cell support for primary breast cancer in patients with 4-9 involved axillary lymph nodes.

Breast cancer patients with more than three involved axillary lymph have a high likelihood of relapse after adjuvant therapy. Early results of administration of high-dose chemotherapy (HDCT) and autologous peripheral blood progenitor cells (PBPC) to patients with primary breast cancer and > or = 10 involved axillary nodes have been encouraging. We performed a multicenter trial to determine whether HDCT could be safely administered to patients with primary breast cancer involving 4-9 axillary lymph nodes. Fifty-four patients with stage II or III breast cancer and 4-9 involved axillary lymph nodes received doxorubicin-based induction chemotherapy, followed by high-dose cyclophosphamide (5.625 g/m2), cisplatin (165 mg/m2), and BCNU (450 mg/m2) and PBPC mobilized by sargramostim (GM-CSF) or filgrastim (G-CSF). After completion of HDCT, patients received radiation therapy to the chest wall or involved breast, plus tamoxifen. Survival and disease-free survival, time to engraftment, and charges associated with HDCT were determined. Plasma concentrations of BCNU were determined and plasma AUC(BCNU) was calculated. Fifty-four patients were evaluable for survival and relapse-free survival. Fifty-two patients received HDCT with PBPC support and were evaluable for toxicity. Fifteen patients (29%) developed late pulmonary drug toxicity, which resolved with a 10-week course of corticosteroids in all but one affected patient, who subsequently died of pulmonary toxicity. Ten patients relapsed a median of 426 days (range 86-1117 days) after the start of induction chemotherapy, seven of whom have died. Forty-three patients are alive and breast cancer-free at a median of 947 days (range 661-1730 days) after the start of therapy, including one patient who developed myelodysplastic syndrome 809 days after the start of HDCT. Actuarial 4-year survival and disease-free survival from the start of treatment are 84 and 71%, respectively. Mean plasma AUC(BCNU) was 400 (range 82-1255) microgxmin/ml and was not statistically different from that measured in historical controls who received 600 mg/m2 of BCNU. Combined hospital and physician charges for patients treated at the University of Colorado decreased from a mean of $125845 for the first four patients to $77126 for the final seven patients. We conclude that HDCT with autologous PBPC can be administered with acceptable safety to patients with primary breast cancer involving 4-9 axillary lymph nodes. An ongoing, prospective randomized trial is evaluating the efficacy of HDCT for this patient group.

Adult↗

PubMed1996

Body size indices and breast cancer risk before and after menopause.

The relationship between various body size indices and breast cancer risk before and after menopause was elucidated by means of a case-control study conducted between June 1991 and April 1994 in 6 Italian centers on 2,569 patients aged below 75 with histologically confirmed breast cancer, and on 2,588 controls admitted to the hospital for a wide spectrum of acute, non-neoplastic, non-hormone-related diseases. Weight and, more consistently, body mass index (BMI, kg/m2) at diagnosis were inversely related to pre-menopausal breast cancer risk and directly to post-menopausal risk. An 8-unit increase in BMI resulted in an odds ratio of 0.8 for pre-menopausal and of 1.2 (significant) for post-menopausal women. Risk seemed to increase gradually after menopause in the 7th (OR for an 8-unit BMI increase, 1.3) and 8th decades (OR, 1.6) of life. Conversely, height, waist-to-hip ratio, bra cup size and weight (or BMI) in adolescence and in young adulthood did not exert a significant or consistent influence on breast cancer risk. The apparent relationship with BMI at middle age and weight gain between age 30 years and diagnosis was eliminated by allowance for BMI at diagnosis. The age-related pattern of the association between BMI and breast cancer risk after menopause may reflect a duration-risk relationship, and resembles the effect of post-menopausal estrogen use, which seems greater among older women.

Adult↗

PubMed1995

Increased risk of craniosynostosis with higher antenatal maternal altitude.

BACKGROUND: During the 1980s, the Colorado Department of Health received reports from several high-altitude communities of clusters of the malformation craniosynostosis. In a population-based, case-control study, we examined the association between overall and trimester-specific maternal antenatal altitude exposure and the occurrence of infant craniosynostosis. METHODS: We identified case children through a statewide registry and randomly sampled control children from birth records. By telephone interview, each mother provided data on the locations of all antenatal residences and places of employment as well as other factors. Staff mapped all locations and abstracted the corresponding altitudes. RESULTS: The odds ratio (OR) of any synostosis for a time-weighted mean antenatal altitude of > or = 2000 metres (high altitude) versus < 2000 metres (low altitude) was 1.4 (lower bound of the one-sided 95% test-based confidence interval (CI): 0.9). The OR was elevated in smokers but not in non-smokers. As compared to non-smokers, the OR of any synostosis for high-altitude smokers was 4.6 (lower bound of the 95% one-sided exact CI: 1.7). Particularly elevated were the corresponding OR of coronal (18.1, 4.4) and metopic synostosis (16.3, 2.8), and OR for high-altitude exposure during the second trimester (any synostosis: 6.4, 1.99; coronal: 28.6, 6.1; metopic: 26.7, 4.1). CONCLUSIONS: Antenatal maternal high-altitude exposure and smoking are associated with increased risk of infant craniosynostosis, perhaps through generation of intermittent hypoxaemia.

Altitude↗

PubMed1994

Increased risk of craniosynostosis with maternal cigarette smoking during pregnancy.

We analyzed data from a population-based case control study to determine whether maternal prenatal smoking or alcohol drinking might increase the risk of craniosynostosis. Between 1986 and 1989, the Colorado Craniosynostosis Registry ascertained 233 children whose diagnoses were confirmed by an independent radiologist. Of the 212 (91%) cases who participated 86 had lambdoid, 69 had sagittal, 25 had coronal, 18 had metopic, and 14 had multiple suture synostosis. Random sampling of birth certificate records yielded 367 eligible controls, of whom 291 (79%) participated. Study staff interviewed case and control mothers between 1989 and 1991 for prenatal smoking and alcohol drinking. We used Mantel-Haenszel and polychotomous logistic regression techniques to estimate the relative odds of craniosynostosis for smoking and drinking in all cases and in relevant case subgroups. Smoking was associated with a relative odds of craniosynostosis of 1.7 (95% confidence interval, 1.2-2.6). For smoking of more than one pack per day, the relative odds were 3.5 (1.5-8.4) for all types of synostosis combined, and 5.6 (2.1-15.3) for coronal synostosis. No strong or significant association was noted for drinking. Maternal prenatal smoking may increase the risk of craniosynostosis in this population.

Adult↗

PubMed1994

A prospective study of heparin-induced osteoporosis in pregnancy using bone densitometry.

OBJECTIVE: Our purpose was to evaluate the subclinical occurrence of heparin-induced osteoporosis in pregnancy, by means of bone densitometry. STUDY DESIGN: A prospective, consecutive cohort of 14 pregnant women requiring heparin therapy and 14 pregnant controls matched for age, race, and smoking status was identified by 20 weeks' gestation at a university medical center. Proximal femur bone density measurements were taken at baseline, immediately post partum, and 6 months post partum in the cases and controls. Vertebral measurements were also obtained on both groups immediately post partum and 6 months post partum. Bone density as a function of heparin dosing and duration was examined. Nonparametric statistical tests were used for all comparisons. RESULTS: Five of 14 cases (36%) had a > or = 10% decrease from the baseline proximal femur measurements to immediate postpartum values versus none of the 14 matched controls (p = 0.04). Mean proximal femur bone density measurements also decreased in the cases (p = 0.01); this difference continued to be statistically significant 6 months post partum (p = 0.03). No dose-response relationship could be demonstrated. CONCLUSION: Heparin adversely affected bone density in about one third of exposed patients.

Absorptiometry, Photon↗

PubMed1994

Risk factors for delayed immunization against measles, mumps, and rubella in Colorado two-year-olds.

OBJECTIVES: 1) To examine a wide range of potential risk factors for delayed childhood immunization against measles, mumps, and rubella and 2) to determine the parental response to proposed solutions regarding the problem of delayed childhood immunization. DESIGN: A case-control study in which subjects had (controls) or had not (cases) received measles, mumps, and rubella vaccine (MMR) by 2 years of age. Parents of subjects were also surveyed to find out whether they thought selected proposals to improve immunization rates would be successful. RESULTS: Maternal education of high school or less at the time of the child's birth, more than or equal to two moves between birth and age 2, maternal age < 21 years of age at the time of the child's birth, more than or equal to two older siblings, participation in The Special Supplemental Food Program for Women, Infants, and Children (WIC), participation in the federal food stamp program, and incorrect knowledge of the recommended age for MMR significantly elevated the odds ratio (OR) for delayed immunization. At least two older siblings (OR = 3.2), maternal age < 21 years of age at the time of the child's birth (OR = 2.8), and incorrect knowledge of the recommended age for MMR (OR = 2.7) remained significant risk factors in a multivariate logistic regression model. Insurance status and cost factors were not significant risk factors for delayed immunization. Parents though that reminders for immunization and a central record system would have made obtaining immunizations easier. CONCLUSIONS: Based on our findings of the importance of immunization knowledge and demographic characteristics as risk factors for delayed immunization, we suggest that a message (the recommended age for immunizations) and a target group for that message (families who move frequently, have older children, and are headed by younger parents) be evaluated as an intervention to improve immunization rates.

Adult↗

PubMed1993

Cautions in the use of antecedents as surrogates for confounders.

When lacking information on confounding variables, epidemiologists have used surrogates which are antecedents of both the exposures and confounders of interest. The usefulness of this strategy is explored in a series of scenarios for a prospective epidemiologic study wherein risk ratios relating antecedent to confounder, antecedent to exposure, and confounder to exposure were varied. Antecedent-adjusted, confounder-adjusted, and crude risk ratios were calculated and compared. The antecedent-adjusted risk ratio was useful, that is, was closer to the confounder-adjusted risk ratio than was the crude risk ratio, in 1,067 (49%) of 2,187 scenarios. The antecedent-adjusted risk ratio, the crude risk ratio, and the risk ratio relating confounder to exposure together predicted the usefulness of the antecedent (or any variable) as a confounder proxy. The antecedent was useful in 97% of scenarios wherein: 1) the antecedent-adjusted risk ratio was less than the crude risk ratio, and the risk ratio relating confounder to exposure was greater than 1.0, or 2) the antecedent-adjusted risk ratio was greater than the crude risk ratio, and the risk ratio relating confounder to exposure was less than 1.0. In the remaining scenarios, it was useful only 5% of the time.

Causality↗