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PubMed1985

Measurement of glomerular filtration rate: single injection plasma clearance method without urine collection.

Glomerular filtration rate (GFR) can be calculated from the plasma clearance of any of several radiopharmaceuticals that are excreted by glomerular filtration. Simplified methods have been proposed that require only one or two plasma samples in lieu of a more complete clearance curve. We examined the error introduced by this simplification. Forty patients were studied using a dual-isotope technique employing [99mTc]DTPA and [169Yb]DTPA, obtaining eight plasma samples for each clearance curve at intervals from 10 to 240 min after injection. Data were fit to several empirical or semiempirical formulae and also to a two-compartment computer model that permitted GFR estimation from only one or two data points. The computer model gave good fit, but so did several simpler methods. The error that results from replacing the complete clearance curve by a single 3-hr sample was about 8 ml/min (residual s.d.). By using two samples (at 1 and 3 hr), the error could be reduced to 4 ml/min. Recommended one- and two-sample methods are presented.

Glomerular Filtration Rate↗
PubMed2003

Impact of rivastigmine on costs and on time spent in caregiving for families of patients with Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) places a significant burden on health care systems worldwide. As new treatments are developed, their cost-effectiveness is often assessed to help health care professionals make informed decisions. In addition to the more common practice of assessing direct medical costs, indirect costs, including time spent in caregiving, should be evaluated. METHODS: This study examined the potential effects of the dual cholinesterase inhibitor rivastigmine (Exelon) on caregivers of patients with AD. Results from two 26-week, placebo-controlled trials have demonstrated the clinically relevant and statistically significant efficacy of rivastigmine (6-12 mg/day) compared to placebo, on cognition, activities of daily living, and global functioning. By delaying progression of AD, significant savings in caregiver burden are anticipated, as measured by time spent caregiving and its related costs. Data collected in a prospective, observational study of AD patients and their caregivers were used to establish the relationship between disease severity (based on Mini-Mental State Examination [MMSE] score) and time spent caregiving (according to the 5-item Caregivers Activity Survey score). A significant correlation was observed between the two scores (N = 43, r = -.56, p < .0001), demonstrating that more time for supervision from caregivers is required as the disease progresses. This finding was used to estimate the reduced caregiver burden resulting from the delay in disease progression that was demonstrated with use of rivastigmine. RESULTS: Over a 2-year period, the reduction in time spent in caregiving reached 691 hours for caregivers of patients with mild AD (MMSE score 21-30), resulting in a total savings of approximately 11,253 dollars. Treatment of patients with moderately severe AD was also evaluated. The trend was similar but the impact was less, suggesting an economic benefit to early therapy. CONCLUSION: Early diagnosis and a pharmacologic intervention that allows the patients to remain at home longer by delaying disease progression would have a beneficial impact on patients, caregivers, and payers, and should therefore be encouraged through initiatives designed to identify and treat patients early in the course of disease.

Activities of Daily Living↗
PubMed2003

Postural stability in the elderly during sensory perturbations and dual tasking: the influence of refractive blur.

PURPOSE: To determine the influence of refractive blur on postural stability during somatosensory and vestibular system perturbation and dual tasking. METHODS: Fifteen healthy, elderly subjects (mean age, 71 +/- 5 years), who had no history of falls and had normal vision, were recruited. Postural stability during standing was assessed using a force platform, and was determined as the root mean square (RMS) of the center of pressure (COP) signal in the anterior-posterior (A-P) and medial-lateral directions collected over a 30-second period. Data were collected under normal standing conditions and with somatosensory and vestibular system perturbations. Measurements were repeated with an additional physical and/or cognitive task. Postural stability was measured under conditions of binocular refractive blur of 0, 1, 2, 4, and 8 D and with eyes closed. The data were analyzed with a population-averaged linear model. RESULTS: The greatest increases in postural instability were due to disruptions of the somatosensory and vestibular systems. Increasing refractive blur caused increasing postural instability, and its effect was greater when the input from the other sensory systems was disrupted. Performing an additional cognitive and physical task increased A-P RMS COP further. All these detrimental effects on postural stability were cumulative. CONCLUSIONS: The findings highlight the multifactorial nature of postural stability and indicate why the elderly, many of whom have poor vision and musculoskeletal and central nervous system degeneration, are at greater risk of falling. The findings also highlight that standing instability in both normal and perturbed conditions was significantly increased with refractive blur. Correcting visual impairment caused by uncorrected refractive error could be a useful intervention strategy to help prevent falls and fall-related injuries in the elderly.

Aged↗
PubMed2005

Relationship among MRTA, DXA, and QUS revisited.

Inexpensive, commercially produced devices that directly measure bone strength in vivo are not currently available. Mechanical response tissue analysis (MRTA), a unique prototype device, is an in vivo vibrational test that measures transverse bending stiffness (a measure of whole bone strength expressed as the product of estimated Young's modulus of elasticity and cross-sectional moment of inertia, EI, Nm2) at ulna midshaft. We compared speed of sound (SOS; [m/s]) in ulna cortical bone using a commercially available axial transmission quantitative ultrasound (QUS) device with EI using MRTA. Dual-energy X-ray absorptiometry (DXA) was used to provide an estimate of ulna size (cm2), bone mineral content (BMC; [g/cm]) and areal bone mineral density (BMD; [g/cm2]). The objective of the study was to determine if ulna SOS--alone or in combination with BMD from DXA--was correlated with ulna EI, thus becoming a surrogate measure of transverse bending stiffness, and thus whole bone strength. Data were collected from 138 female volunteers (18-86 yr). EI and SOS were significantly correlated, r = +0.218, p = 0.01, but r2 was very low, 4.8%. SOS and total ulna BMD were combined to estimate elastic modulus, which correlated with EI, r = +0.377, p < 0.0001; however, the correlation was not significantly better than with SOS alone. We conclude that axial transmission QUS is not a strong surrogate in vivo technique for estimating transverse bending stiffness.

Absorptiometry, Photon↗
PubMed1995

Parent and student preferences for services in a school-based clinic.

As a component of program planning for a school-based clinic in a suburban high school, a sample of 199 students and 196 parents were surveyed about preferences for health services. Parents and students were asked about health services desired and level of interest. Student overall interest in health services was less than parent interest, although both groups indicated at least a moderate level of interest. Both students and parents reported interest in availability of comprehensive services, including general health services, reproductive health services, and counseling services. The process of polling parents and students serves dual purposes of informing the population about school-based clinics, as well as gathering information to attempt to match the health services offered with needs identified.

Adolescent↗
PubMed1992

Mathematical examination of dual individualization principles. (III): Development of a scoring system for pneumonia staging and quantitation of response to antibiotics: results in cefmenoxime-treated patients.

OBJECTIVE: In order to quantitatively express the important, time-related aspects of response to antimicrobial therapy in patients with pneumonia, we required validated measures of the time course of events during the infection. To quantitate the changes in clinical status in relation to changes in cultures, we developed a scoring system to be used for patient assessment during therapy. DESIGN: Retrospective data collection, prospective analysis of factors. SETTING: Intensive care unit, Millard Fillmore Hospital. PATIENTS: Twenty-eight patients with nosocomial pneumonia. MAIN OUTCOME MEASURES: Clinical parameters were assessed daily for the duration of antimicrobial therapy. Using linear regression, the rate of clinical change in each patient treated was quantified. Eradication of the pathogen was determined by serial cultures of the infection site. RESULTS: Seventeen of the patients demonstrated eradication of the organism, and 11 demonstrated persistence of the pathogen (7 were considered colonization). The system described the patients at baseline in that the mean baseline scores were similar in both groups of patients (p = 0.79). Patients in whom the pathogen was eradicated showed a rate of clinical improvement significantly different from those who had persistence of the organism (p = 0.04). In patients demonstrating eradication, the time to eradication inversely correlated with the rate of clinical improvement (p < 0.05). Of the ten parameters descriptive of the disease, those most sensitive to change after eradication of bacteria were body temperature, bacterial Gram stain, white blood cell Gram stain, and volume of sputum. CONCLUSIONS: In this set of pneumonia patients, the scoring system effectively quantified both baseline and time-related changes in clinical status. The system distinguished between the clinical course of the patient with organism eradication versus organism persistence. A shorter time to eradication was associated with a better clinical response. Prospective study of the system will determine its sensitivity.

Aged↗
PubMed1996

Collimator-related radiation dose for different cobalt machines and linear accelerators.

PURPOSE: In previous publications (12, 13) measurements are described of the dose outside the primary beam (the peripheral dose (PD)) for 60Co gamma radiation to 25 MV photons. Comparison with data published by other investigators for different treatment machines, showed good agreement. This can only be explained when the contribution to the PD of radiation leaking through and scattering from the collimator does not differ considerably between treatment machines from different manufactures, and it is the purpose of this article to investigate whether this assumption is valid. METHODS AND MATERIALS: A request was sent out to all radiotherapy departments in The Netherlands and one in Belgium to measure the dose outside the primary beam for as many machines as possible. The following geometry was given: field sizes of 10 x 10 cm2 and 20 x 20 cm2 at distances of 30 and 50 cm, for collimator angles 0 degrees and 90 degrees at the standard source surface distance. This, therefore, resulted in a dataset of eight measurements per photon energy. RESULTS: Data were collected for four cobalt machines and 37 linear accelerators, from seven different manufacturers. All together 56 datasets were collected for 12 different photon energies. Although the variation of the leakage radiation dose is small, there can be differences of about 50% in the collimator scatter dose between collimator angles of 0 degrees and 90 degrees, depending on the collimator design or on the design of the flattening filter. For dual energy machines with a large gap between the low and the high energy, the values for the high energy are higher by about 40%. Old cobalt machines show higher leakage radiation dose than modern ones. CONCLUSION: Although there is no large variation in leakage radiation dose between different makes of accelerators, some show higher collimator scatter dose than others. The magnitude of the leakage radiation dose is well within regulatory limits. As the PD not only consists of a contribution from collimator-related radiation, but also of patient scatter, the differences are negligible when estimating the peripheral dose for an individual patient.

Cobalt↗
PubMed2026

GmMYB29 activates Gm4CL3 to enhance soybean resistance to Heterodera glycines.

Soybean cyst nematode is a devastating soil-borne pathogen that severely limits soybean yield worldwide. To uncover downstream target genes of the resistance-associated transcription factor GmMYB29, we combined ChIP-seq and RNA-seq data from T3-generation GmMYB29-overexpressing soybean plants, alongside Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, to screen candidate genes carrying transcription factor binding peaks within the 2000 bp region upstream of transcription start sites (TSS). Four orthogonal molecular assays-yeast one-hybrid (Y1H), electrophoretic mobility shift assay (EMSA), dual-luciferase reporter (LUC) system, and GUS histochemical staining-collectively confirmed the specific physical interaction between GmMYB29 and the promoter of Gm4CL3. We generated transgenic soybean hairy roots overexpressing Gm4CL3 (OX-Gm4CL3) and CRISPR-Cas9-mediated Gm4CL3 knockout lines (KO-Gm4CL3), with wild-type (WT) plants serving as controls. Inoculation assays using SCN 3 demonstrated that OX-Gm4CL3 roots displayed substantially improved SCN resistance, while KO-Gm4CL3 roots were hypersusceptible to nematode infection. Mechanistic investigations revealed that Gm4CL3 promotes lignin deposition in root tissues to block SCN penetration. Furthermore, GmMYB29 and Gm4CL3 act synergistically to activate lignin biosynthetic pathways and strengthen soybean resistance against SCN 3 (SCN Race 3, the dominant physiological race in Northeast China). In summary, this study functionally characterizes Gm4CL3 and defines a previously unreported GmMYB29-Gm4CL3 regulatory cascade that mediates plant defense against SCN. This module functions independent of classic SCN resistance loci rhg1/Rhg4, providing new genetic resources for SCN-resistant soybean molecular breeding.

Glycine max↗
PubMed2003

Posttraumatic stress disorder among Hispanic and African-American drug users.

CONTEXT: Treating high-risk substance abusers who are members of minority groups may require varied protocols depending on differences among minority groups. OBJECTIVES: To explore cocaine abuse (CA)/ dependence with physiological dependence (CDPD) and posttraumatic stress disorder (PTSD) diagnosis differences between out-of-treatment Hispanic and African American adults, in order to identify cultural differences in how experiences and attitudes affect cocaine use behaviors. DESIGN, SETTING, AND PARTICIPANTS: This study uses data collected between February and November 2000, as part of a three-year longitudinal study. A cohort of 347 out-of-treatment, Hispanic and African American cocaine-using adults from the Houston metropolitan area were interviewed to measure differences between cocaine users who are dually diagnosed and those that are not. MAIN OUTCOME MEASURES: Meeting the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. criteria for dual diagnoses of CA/PTSD or CDPD/PTSD. RESULTS: For the dual diagnoses categories, 102 (29%) participants met the requirements for CA/PTSD or CDPD/PTSD. Logistic regression models were used, with CA/PTSD and CDPD/PTSD as the dependent variables. Age, race, gender, and income were used as the independent variables. Results indicate that individuals with higher income have a greater probability of developing CA/PTSD (beta = 0.919, p < 0.05). For both dual diagnoses categories of CA/PTSD and CDPD/ PTSD, results indicate that being female increases the likelihood of developing both of these dual diagnoses, (beta = 2.106, p < 0.05) or (beta = 2.510, p < 0.05). However, being an older female decreases the probability that an individual would develop these dual diagnoses (beta = -2.227, p < 0.05) (beta = -2.577, p < 0.05). CONCLUSIONS: No differences were found for race/ethnicity among the dually diagnosed Hispanics and African Americans, however, gender differences were found. Being female increases an individual's probability of developing a dual diagnosis of CA/PTSD or CDPD/PTSD. In addition to being female, being a young female further increases an individual's probability of being dually diagnosed.

Adult↗
PubMed2003

Metabolic and endocrinologic complications in beta-thalassemia major: a multicenter study in Tehran.

ABSTRACT : BACKGROUND : The combination of transfusion and chelation therapy has dramatically extended the life expectancy of thalassemic patients. The main objective of this study is to determine the prevalence of prominent thalassemia complications. METHODS : Two hundred twenty patients entered the study. Physicians collected demographic and anthropometric data and the history of therapies as well as menstrual histories. Patients have been examined to determine their pubertal status. Serum levels of 25(OH) D, calcium, phosphate, iPTH were measured. Thyroid function was assessed by T3, T4 and TSH. Zinc and copper in serum were determined by flame atomic absorption spectrophotometry. Bone mineral density (BMD) measurements at lumbar and femoral regions have been done using dual x-ray absorptiometry. The dietary calcium, zinc and copper intakes were estimated by food-frequency questionnaires. RESULTS : Short stature was seen in 39.3% of our patients. Hypogonadism was seen in 22.9% of boys and 12.2% of girls. Hypoparathyroidism and primary hypothyroidism was present in 7.6% and 7.7% of the patients. About 13 % of patients had more than one endocrine complication with mean serum ferritin of 1678 +/- 955 micrograms/lit. Prevalence of lumbar osteoporosis and osteopenia were 50.7% and 39.4%. Femoral osteoporosis and osteopenia were present in 10.8% and 36.9% of the patients. Lumbar BMD abnormalities were associated with duration of chelation therapy. Low serum zinc and copper was observed in 79.6% and 68% of the study population respectively. Serum zinc showed significant association with lumbar but not femoral BMD. In 37.2% of patients serum levels of 25(OH) D below 23 nmol/l were detected. CONCLUSION : High prevalence of complications among our thalassemics signifies the importance of more detailed studies along with therapeutic interventions.

Journal Article↗
PubMed1997

Transcytosis of albumin in endothelial cells is brefeldin A--independent.

To determine whether in endothelial cells (EC) the pathways of endocytosis and transcytosis of macromolecules interconnect, the effect of Brefeldin A (BFA) on these processes was tested. To this purpose EC were grown to confluence on plastic culture dishes or on cell culture chamber inserts placed into corresponding wells, so as to obtain a dual chamber system. The cells maintained the typical characteristics of EC and had an electrical resistance in the range of 30-60 Ohm.cm2. Transendothelial transport of albumin conjugated to the fluorochrom Texas Red (Alb-TR) and of horseradish peroxidase (HRP) added to the upper compartment, in the absence or presence of BFA (0-25 micrograms/ml), was evaluated in aliquots collected from the lower compartment. At different time intervals, quantitative data were obtained by fluorimetry and spectrophotometry. In other experiments transcytosis of Alb-TR was examined in the presence of 100 microM forskolin (an inhibitor of BFA effect). The endocytosis of Alb-TR and HRP was evaluated by incubating EC with the probes, and the internalized tracers determined in the cell lysate using the methods described above. The results showed that BFA has no significant effect on transcytosis of albumin and HRP. In contradistinction, BFA (5 micrograms/ml) reduced markedly endocytosis of HRP (by 47%). Forskolin has no effect on transcytosis. The data indicate that the BFA-induced perturbance in the endocytic route does not affect the transcytotic pathway of albumin, and suggest that in EC, transcytosis of macromolecules may represent a shortcut for rapid and direct transport of some plasma molecules across the cell.

Animals↗
PubMed2000

Immunolocalization of androgen receptors and aromatase enzyme in the adult musk shrew brain.

In the brain and other tissues, estrogens are produced by aromatization of androgens. Biochemical data suggest that aromatase enzyme is regulated by the androgen receptor (AR). Neurons that contain either AR or aromatase (AROM) enzyme reside in many of the same brain regions. In this report, we examined the codistribution of AR- and AROM-enzyme-immunoreactive (-ir) neurons in several regions of the adult male and female musk shrew brain. Data were collected from the intermediate nucleus of the lateral septum (LS), medial anterior (BNSTMA) and medial posterointerior (BNSTMP) divisions of the bed nucleus of the stria terminalis, medial preoptic area (mPOA), ventromedial nucleus of the hypothalamus (VMN), medial (MeA), cortical and central nuclei of the amygdala. Males had significantly more AR-ir neurons in the BNSTMP, mPOA, VMN and LS as compared to females. With the exception of the BNSTMA and LS, males had more AROM-ir neurons in each region than females. Furthermore, males had significantly more double-labeled neurons than females in the BNSTMP, mPOA, VMN, LS and MeA. The percentage of AROM-ir neurons that also contained AR immunoreactivity ranged from 13 to 82% depending on sex and region. The highest percentage of dual-labeled neurons (79% in females and 82% in males) was found in the VMN. Taken together, these data show that there is extensive cellular colocalization of AR and AROM enzyme in specific regions of the musk shrew brain. We propose that in both sexes, androgen receptors may act as transcription factors to regulate AROM enzyme.

Age Factors↗
PubMed2004

Economic evaluations of HIV treatment and health research with people diagnosed with HIV infection and co-occurring mental health and substance use disorders.

This paper describes the research challenges involved in measuring costs in economic evaluations of patients who are coping simultaneously with HIV/AIDS and co-occurring mental health and substance abuse disorders-especially in multi-site studies. We describe the general issues that arise in measuring costs for this population and suggest some operational solutions for their resolution, drawing from our experience in a recent multi-site health services research study focused on this population. We show that while reliance on patient self-report data may be unavoidable to provide a common denominator in multi-site studies, there are also some practical ways of improving the accuracy of such data and the cost estimates that result from them. We also provide readers with a means for securing the data collection instruments developed for the cost component of this study in the hope that these may serve as templates for researchers doing similar work.

Cost-Benefit Analysis↗
PubMed2002

Dual dependence: assessment of dependence upon alcohol and illicit drugs, and the relationship of alcohol dependence among drug misusers to patterns of drinking, illicit drug use and health problems.

AIMS: The study investigates severity of alcohol dependence among drug misusers. Specifically, it investigates the inter-relationship of alcohol and drug dependence and associations with alcohol consumption, drug consumption and substance-related problems. DESIGN, SETTING, PARTICIPANTS: The sample comprised 735 people seeking treatment for drug misuse problems, who were current (last 90 days) drinkers. MEASUREMENTS: Data were collected by structured face-to-face interviews. Dependence upon illicit drugs and upon alcohol was measured by the Severity of Dependence Scale (SDS). FINDINGS: Three groups of drinkers were identified: non-alcohol-dependent drug misusers (63%); low-dependence (19%); and high-dependence (18%). Many drug misusers were drinking excessively and alcohol dependence was related to patterns of alcohol and drug consumption. High-dependence drinkers were more likely to drink extra-strength beer; they were less frequent users of heroin and crack cocaine but more frequent users of benzodiazepines, amphetamines and cocaine powder; they reported more psychological and physical health problems. The SDS was found to have good reliability and validity as a measure of alcohol dependence. SDS scores for alcohol and drug dependence were unrelated. CONCLUSIONS: Alcohol use is an important and under-rated problem in the treatment of drug misusers. A comprehensive assessment of alcohol use among drug misusers should include separate assessments of alcohol consumption, alcohol-related problems and severity of alcohol dependence.

Adult↗
PubMed2002

Poor intestinal permeability in mildly stunted Nepali children: associations with weaning practices and Giardia lamblia infection.

Studies in the Gambia, using the lactulose-mannitol dual-sugar intestinal permeability test (lactulose:mannitol ratio) as a non-invasive way of investigating mucosal damage, have shown that food malabsorption is significantly associated with early growth retardation. In this cross-sectional study, 210 poor urban Nepali children, 0-60 months old, were recruited and measured for height or length and weight, 167 were examined for intestinal permeability and 173 for parasite infection. Weaning and morbidity data were collected from 172 caretakers. Children were mildly stunted (mean height-for-age z-score -1.45) and underweight (mean weight-for-age z-score -1.62). The lactulose:mannitol ratio (0.26) was poorer than that of UK children (0.12), but similar to that found in Bengali children of the same age (0.24). Two stages of weaning, the onset supplementary feeding (6 months) and the cessation of breast-feeding (23 months), were shown to have differential impact. In children currently breast-feeding, the duration of supplementation was negatively related to lactose (P<0.001) and lactose:lactulose values (P<0.0001), indicating lactose maldigestion. In children who had ceased breast-feeding, a longer period of lactation was associated with poorer intestinal permeability (P=0.031), and poorer height-for-age (P=0.024), which was an unexpected result. No significant relationships were found between intestinal permeability and growth, or with morbidity and helminth infection, except in children with Giardia lamblia who had worse lactulose:mannitol ratios than those without (0.43 v. 0.25 respectively, P=0.014). It is likely that insults to the gut (e.g. Giardia) and challenges to the immune system (weaning) have a different impact in early and late infancy.

Animals↗
PubMed2004

An evaluation of collaborative interventions to improve chronic illness care. Framework and study design.

The author's dual-purpose evaluation assesses the effectiveness of formal collaboratives in stimulating organizational changes to improve chronic illness care (the chronic care model or CCM). Intervention and comparison sites are compared before and after introduction of the CCM. Multiple data sources are used to measure the degree of implementation, patient-level processes and outcomes, and organizational and team factors associated with success. Despite challenges in timely recruitment of sites and patients, data collection on 37 participating organizations, 22 control sites, and more than 4,000 patients with diabetes, congestive heart failure, asthma, or depression is nearing completion. When analyzed, these data will shed new light on the effectiveness of collaborative improvement methods and the CCM.

Chronic Disease↗
PubMed1991

Peritoneal macrophages from patients on continuous ambulatory peritoneal dialysis have an increased capability to release tumour necrosis factor during peritonitis.

We have reported previously that human peritoneal macrophages collected from patients on Continuous Ambulatory Peritoneal Dialysis (CAPD) during an episode of peritonitis secrete increased amounts of interleukin-1 (IL-1), as compared to those collected during an infection free period, provided the cells were stimulated in vitro by LPS. We now report that such macrophages release also higher amounts of Tumor Necrosis Factor (TNF), if collected during peritonitis and stimulated subsequently in vitro by LPS. The increase in release of TNF was ascertained by radio-immunoassays as well as by bioassay of cytostatic effect against the highly sensitive TNF target-cell line L929 murine transformed fibroblasts. The present reported results, in addition to previously reported data on release of IL-1, indicate that induction of release of cytokines from human peritoneal macrophages is a dual stepwise process: first priming in vivo in an inflammatory environment and, secondly stimulation in vitro by LPS.

Adult↗
PubMed1996

Does induced or spontaneous abortion affect the risk of breast cancer?

The influence of induced or spontaneous abortion on breast cancer risk has been the subject of numerous epidemiologic studies over the past decades and has recently received heightened attention. Here, we review the evidence to understand better the apparent inconsistencies among studies. We considered possible biases in data collection, presentation, and analysis that could create spurious associations or obscure real relations. A particularly important issue is the sensitive nature of abortion, which is a pervasive problem that could affect the validity of many studies. Also, an incomplete pregnancy deprives the woman of a potentially protective full-term pregnancy and therefore may appear harmful when compared with the experience of a woman who did carry to term. The dual effect of parity on breast cancer risk-short-term risk increase and long-term protection-adds another dimension of complexity to the interpretation of abortion studies. Long-term influences of abortion may have been insufficiently captured in some studies, as follow-up time was too short. Studies to date are inadequate to infer with confidence the relation between induced or spontaneous abortion and breast cancer risk, but it appears that any such relation is likely to be small or nonexistent.

Abortion, Induced↗