Prediction equations do not eliminate systematic error in self-reported body mass index

Epidemiological studies of the risks of obesity often use body mass index (BMI) calculated from self-reported height and weight. The purpose of this study was to examine the pattern of reporting error associated with self-reported values of BMI and to evaluate the extent to which linear regression models predict measured BMI from self-reported data and whether these models could compensate for this reporting error. We examined measured and self-reported weight and height on 5079 adults aged 30 years to 64 years from the second National Health and Nutrition Examination Survey. Measured and self-reported BMI (kg/m2) was calculated, and multiple linear regression techniques were used to predict measured BMI from self-reported BMI. The error in self-reported BMI (self-reported BMI minus measured BMI) was not constant but varied systematically with BMI. The correlation between measured BMI and the error in self-reported BMI was -0.37 for men and -0.38 for women. The pattern of reporting error was only weakly associated with self-reported BMI, with the correlation being 0.05 for men and -0.001 for women. Error in predicted BMI (predicted BMI minus measured BMI) also varied systematically with measured BMI, but less consistently with self-reported BMI. More complex models only slightly improved the ability to predict measured BMI compared with self-reported BMI alone. None of the equations were able to eliminate the systematic reporting error in determining measured BMI values from self-reported data. The characteristic pattern of error associated with self-reported BMI is difficult or impossible to correct by the use of linear regression models.

The body mass index-mortality relationship in white and African American women

OBJECTIVE

To examine the association of body mass index to all-cause and cardiovascular disease (CVD) mortality in white and African American women.

RESEARCH METHODS AND PROCEDURES

Women who were members of the American Cancer Society Prevention Study I were examined in 1959 to 1960 and then followed 12 years for vital status. Data for this analysis were from 8,142 black and 100,000 white women. Body mass index (BMI) was calculated from reported height and weight. Associations were examined using Cox proportional hazards modeling with some analyses stratified by smoking (current or never) and educational status (less than complete high school or high school graduate).

RESULTS

There was a significant interaction between ethnicity and BMI for both all-cause (p<0.05) and CVD mortality (p<0.001). BMI (as a continuous variable) was associated with all-cause mortality in white women in all four groups defined by smoking and education. In black women with less than a high school education, there were no significant associations between BMI mortality. For high school-educated black women, there was a significant association between BMI and all-cause mortality. Among never smoking women with at least a high school education, models using the lowest BMI as the reference indicated a 40% higher risk of all-cause mortality at a BMI of 35.9 in black women vs. 27.3 in white women.

DISCUSSION

The impact of BMI on mortality was modified by educational level in black women; however, BMI was a less potent risk factor in black women than in white women in the same category of educational status.

Interobserver reliability of digital and endovaginal ultrasonographic cervical length measurements

OBJECTIVE

Our purpose was to prospectively evaluate the interobserver reliability of digital and endovaginal ultrasonographic cervical length measurements.

STUDY DESIGN

Forty-three women were recruited from our antepartum clinic to participate in this study. Two independent and blinded digital cervical examinations were performed by the first author and a second examiner. Instructions were given to estimate the cervical length in millimeters. After micturition endovaginal ultrasonographic cervical length measurements were performed by two independent, blinded registered diagnostic medical sonographers. Cervical lengths were compared with the Student t test and Pearson's correlation coefficient. A kappa statistic was calculated for interobserver reliability at three levels of agreement +/- 1 mm, +/- 4 mm, and +/- 10 mm. Data are expressed as means +/- SD.

RESULTS

Digital cervical lengths were not different between the two examiners (18.7 +/- 4.8 mm, 20.5 +/- 6.2 mm) nor between the two ultrasonographic measurements (38.6 +/- 6.1 mm, 39.2 +/- 5.4 mm). The digital cervical lengths agreed (+/- 1 mm) 35% of the time (R2 0.10, p = 0.02). The endovaginal ultrasonographic measurements agreed (+/- 1 mm) 74% of the time with a stronger correlation (R2 0.53, p = 0.0001). The kappa statistic for interobserver variability was marginal for both digital and endovaginal cervical length measurements when agreement was defined as +/- 1 mm. Endovaginal ultrasonography was significantly more reliable than digital examination when agreement between examiners was defined as either +/- 4 mm or +/- 10 mm.

CONCLUSION

Although both digital and endovaginal ultrasonographic cervical length measurements show correlation between examiners, endovaginal ultrasonography is significantly more reliable when agreement is defined as > or = +/- 4 mm. Serial cervical length measurements to predict preterm labor will be enhanced by the interobserver reliability of endovaginal ultrasonography.

Anti-sperm antibodies, detected by agglutination, immobilization, microcytotoxicity and immunobead-binding assays

To determine the reliability of tests currently utilized in the detection of sperm-reactive antibodies, sera were provided as unknowns and studied without knowledge of the clinical histories. Four laboratories performed tray agglutination tests (TAT), three complement-dependent immobilization (SIT), and single laboratories sperm cytotoxicity (SCT), passive haemagglutination (PHA) and immunobead binding (IBB). Most investigators demonstrated an excellent correlation between duplicate sample results. Nearly all of the female sera were free of anti-sperm antibodies and positive results did not appear in greater frequency in women with unexplained infertility as compared with other categories. For the male sera, the highest incidence of anti-sperm antibodies in the infertile group (21% positive for sperm-reactive IgGs) was obtained by immunobead binding. The GAT and TAT results gave 7 and 12% positives, except for lower results in one laboratory. Sperm-reactive antibodies were detected most commonly in vasectomized men, with all assays except SCT and PHA. Of the newer techniques studied, IBB results correlated well with TAT, GAT and SIT, while SCT and PHA did not, suggesting that a different group of antibodies, perhaps directed against other sperm-associated antigens, was being detected by the latter procedures. In this light, emphasis was placed on the need to validate whether results of particular methodologies correlated with impaired sperm function and to develop methods that provided evidence for this premise, either on the basis of clinical criteria or altered gamete interaction in vitro.

Predictors of physical disability in elderly blacks and whites of the Charleston Heart Study

During the 1984/85 recall of the Charleston Heart Study Cohort, physical function data were obtained for 247 white males, 376 white females, 123 black males, 247 black females and 71 high socioeconomic status (SES) black males over 60 years of age. Black females had the highest prevalence of physical disability (55.8%), followed by white females (43.2%), black males (39.0%) and white males (25.8%) and high SES black males (22.3%). Physical disability was 1.5-2.5 times as prevalent among individuals with a history of cardiovascular disease (CVD) than those without such a history. Among individuals without a current history of CVD univariate analyses showed the following as significant (lower 95% CI greater than 1.0) predictors of physical disability: elevated systolic blood pressure in white females, black males, and black females; elevated cholesterol in black females; obesity in black females; and low educational level in white females. Regression analyses indicated that obesity in 1960 accounted for 10.9 and 2.9% respectively of the variability in physical disability scores in 1985 for black females and white females.

Body mass index and body girths as predictors of mortality in black and white men

Anthropometric measurements collected from black and white men in the 1960 (n = 946) and 1963 (n = 456) examinations of the Charleston Heart Study cohort (Charleston County, South Carolina) were examined as predictors of all cause and coronary heart disease mortality. Anthropometric measurements included body mass index, chest girth (at the third intercostal space), abdominal girth (at the umbilicus) and midarm circumference. Vital status of 98 percent of the cohort was determined through 1988. Body mass index was not associated with mortality in the white men; however, it was predictive of all cause and coronary heart disease mortality in the black men. Analyses conducted separately in the lower and upper range of body mass index in black men showed the adjusted relative hazard at the 50th versus the 10th percentile of body mass index was 0.54 for all cause mortality, but was not significant for coronary heart disease mortality; whereas the adjusted relative hazard for the 90th relative to the 50th percentile was 1.7 for coronary heart disease deaths, but not significant for deaths from all causes. The circumference measurements were not predictive of all cause or coronary heart disease mortality in the white men. In the black men, the adjusted relative hazard ratios for all cause mortality for the 85th relative to the 15th percentiles were 0.22 for midarm circumference and 2.0 for abdominal circumference.

Endometrial antigens involved in the autoimmunity of endometriosis

Serum and peritoneal fluid from five fertile women without endometriosis and serum (n = 23) and peritoneal fluid (n = 12) from infertile women with endometriosis were tested for the presence of antibodies against endometrial tissue antigens by a Western blot analysis. Antigens with molecular weights (MW) of 19, 31, 38, and 42 kd reacted with antibodies in the serum and peritoneal fluid from both fertile and infertile women. Antibodies in 20 of 23 (87%) sera and all 12 (100%) peritoneal fluid samples from endometriosis patients reacted against endometrial antigens with molecular weights (MW) of 26 kd and/or 34 kd. Serum from 10 patients (43%) and peritoneal fluid from 6 patients (50%) also had antibodies to an endometrial antigen with MW of 21.5 kd. Reactivity to other endometrial antigens with MW 16, 24, 48, and 75 kd was also noted in patients with endometriosis. Antibodies in the serum and peritoneal fluid from fertile women failed to react against these antigens. It is concluded that the humoral and local endometrial autoimmunity detected in patients with endometriosis is primarily directed against antigens with MW of 26 and 34 kd.

Intrafamilial phenotypic expression of autosomal dominant polycystic kidney disease

It has been suggested that the clinical expression of autosomal dominant polycystic kidney disease (ADPKD) is uniform among individuals of a given family. To test this hypothesis, intrafamilial variations in ages at onset of first symptoms, types of first symptoms, serum creatinine concentrations, and renal sizes were evaluated in 131 patients with ADPKD from 36 unrelated families. These parameters were compared in younger and older affected relatives in the same family at a single time, due to difficulties of following them longitudinally. Because the natural course of the disease is to progress with age, it was presumed that disease progression in a given family was nonuniform if older individuals had lower serum creatinine concentrations, and/or smaller kidneys than their affected younger relatives, or if relatives of similar ages had different serum creatinine concentrations and/or kidney sizes. Nonuniform progression was suggested in 38% of affected relatives by serum creatinine concentrations and in 53% by kidney sizes. Ages at onset of first symptoms and types of first symptoms were also different in patients from the same families. These data indicate that phenotypic expression of ADPKD may differ considerably among patients who belong to the same families.

Morphometric discrimination of melanoma in situ of sun-damaged skin from chronically sun-damaged skin

BACKGROUND

The histologic discrimination of melanoma in situ of sun-damaged skin (MIS) from chronically sun-damaged skin (SDS) can sometimes be difficult using accepted criteria.

OBJECTIVE

We evaluated these entities by means of morphometry and multifactorial analysis.

METHODS

We measured the number and area of melanocyte nuclei, melanocyte nucleoli, stratum spinosum keratinocyte nuclei, and papillary dermal lymphocyte nuclei from hematoxylin-eosin-stained slides representing 38 cases of MIS and 18 cases of SDS matched for age, sex, and site with a high-resolution digital imaging and analysis system.

RESULTS

Multiple logistic regression analysis correctly classified 100% of the cases using the number of melanocytes per 0.5 mm and the maximum melanocyte nuclear area divided by the maximum keratinocyte nuclear area. The strongest results were achieved measuring approximately 1 mm of epidermis.

CONCLUSION

Morphometry and multifactorial analysis can distinguish MIS from SDS. Morphometric analysis of melanocytic proliferations may be useful at the margins of surgical resections.

Kinin, a mediator of diabetes-induced glomerular hyperfiltration

Renal kallikrein is increased in diabetic patients and streptozotocin (STZ)-induced diabetic rats with hyperfiltration. Chronic inhibition of renal kallikrein reduces glomerular filtration rate (GFR) and renal plasma flow (RPF) in hyperfiltering STZ-induced diabetic rats. To investigate whether these actions of kallikrein and its inhibition are kinin-mediated, we used a B2-kinin receptor antagonist (BKA). In STZ-induced diabetic rats with hyperfiltration, renal kallikrein excretion rate was significantly increased (P < or = 0.01), and kinin excretion rate was increased 57%, as compared with control rats. Left kidney GFR and RPF were measured before and during a 40-min infusion of BKA (0.5 micrograms.kg-1.min-1) or vehicle. Infusion of the kinin receptor antagonist reduced the GFR and RPF significantly. GFR was reduced by 18%, from an average baseline value of 2.07 +/- 0.11 to 1.70 +/- 0.06 ml/min, P < or = 0.001 (means +/- SE). RPF was reduced by 25%, from 6.74 +/- 0.38 to 5.06 +/- 0.17 ml/min, P < or = 0.001. Total renal vascular resistance was significantly increased during BKA infusion, P < or = 0.001. Vehicle infusion for the same period had no significant effect on GFR, RPF, or renal vascular resistance. These findings further support the hypothesis that increased renal production of kinins contributes to the renal vasodilation of diabetes.

Levels of transferrin and alpha 2-HS glycoprotein in women with and without endometriosis

The study objective was to test the hypothesis that elevated levels of transferrin and alpha 2-HS glycoprotein occur in the peritoneal environment of patients with endometriosis that may lead to the observed autoimmunity to these proteins. We set up a double sandwich enzyme-linked immunosorbent assay (ELISA) for measuring levels of transferrin and alpha 2-HS glycoprotein in the serum and peritoneal fluid samples from women with (n = 24-60) and without endometriosis (n = 35-49). Serum and peritoneal fluid levels of alpha 2-HS glycoprotein and peritoneal fluid levels of transferrin were significantly elevated in patients with endometriosis, in contrast to the controls. Serum levels of transferrin in patients, however, were significantly less in the patients than in controls. We conclude that transferrin and alpha 2-HS glycoprotein are present at high concentrations in the peritoneal fluids of patients with endometriosis. This may play a significant role in the autoimmune pathophysiology of endometriosis.

Human papilloma virus (HPV)-E6/E7 and epidermal growth factor receptor (EGF-R) protein levels in cervical cancer and cervical intraepithelial neoplasia (CIN)

BACKGROUND

About 90% of cervical cancers and advanced cervical intraepithelial neoplasia (CIN II/III) are squamous epithelial cells with mRNA for human papillomavirus (HPV)16 and 18 and up-regulated epidermal growth factor receptor (EGF-R). Since presence of proteins rather than mRNA may be truly indicative of active infection or disease progression, establishing reliable methods for quantifying these proteins in cervical biopsies is important.

METHOD

We have established an objective semi-quantitative immunofluorescent antibody assay to reliably assess the levels of HPV-E6/E7 and EGF-R proteins in the cervical biopsies from 12 normal women, five women with CIN I, 15 with CIN II/III and ten with cervical cancer.

RESULTS

HPV-E6/E7 and EGF-R, when present, were specific to para-basal, basal and squamous epithelial cells (negative in stromal cells). Nine of ten women with cervical cancer and 15 (14 CIN II/III; 1 CIN I) of 20 women with CIN were positive for HPV-E6/E7. All 12 controls were HPV-negative. The controls and six women with CIN (four with CIN I) negative for HPV had low levels of EGF-R. The only exception was one woman with cervical cancer negative for HPV, with high levels of EGF-R. Levels of HPV-E6/E7 and EGF-R were significantly higher (P < 0.001 vs. controls) in women with advanced CIN II and III (P< 0.05 vs. controls in CIN I) and cervical cancer. The HPV-E6/E7 and EGF-R levels correlated significantly (r = 18.98; P < 0.001, by linear regression analysis).

CONCLUSION

We have established a highly specific and sensitive semi-quantitative immunofluorescent antibody assay for measuring levels of HPV-E6/E7 proteins and EGF-R in archival cervical biopsies. Our data suggest an association between HPV-E6/E7 and EGF-R.

Studies on sperm survival and motility in the presence of cytotoxic sperm antibodies

The effect of cytotoxic sperm antibodies and native complement in the serum and secretions from 40 fertile and 93 infertile couples on in vitro sperm survival and motion characteristics was studied. Sperm survival in vitro was unaffected by sera from fertile and infertile subjects without cytotoxic sperm antibodies and from infertile men with antibodies to control but not to autologous sperm. Sperm survival was reduced (P less than .001) by sera from infertile men with antibodies to autologous sperm or to antologous and control sperm and from women with cytotoxic antibodies to sperm from both. Sera from fertile couples without sperm antibodies enhanced sperm swimming speed and motility index (P less than .0001). Sera from infertile women with or without cytotoxic sperm antibodies did not affect sperm motility. Sperm survival and motility were reduced by seminal plasma from infertile men with cytotoxic antibodies to autologous and/or control sperm. Seminal plasma from fertile men enhanced sperm survival. Cervical mucus from infertile women with antibodies to autoimmune husbands' sperm or to husbands' and control sperm inhibited sperm motion, whereas cervical mucus from infertile women without sperm antibodies and women with antibodies to control sperm failed to have any effect. It is concluded that cytotoxic sperm antibodies developed through exposure to sperm antigens in autoimmune infertile men decrease in vitro sperm survival and/or motility.

Sex-hormone-binding globulin in clinically hyperandrogenic women: association of plasma concentrations with body weight

The relationship of sex-hormone-binding globulin (SHBG) with actual body weight (ABW), ideal body weight (IBW), ABW as percentage of the IBW (% IBW), Quetelet index (weight/height2) and plasma concentrations of various androgens and 17 beta-estradiol (E2) were studied in 9 normal and 57 hirsute patients (group 1). In hirsute patients, plasma levels (ng/dl, mean +/- standard error of the mean [SEM]) of testosterone (T; 77 +/- 4), dihydrotestosterone (DHT; 26 +/- 2), androstenedione (delta 4A; 184 +/- 16), and SHBG (0.91 +/- 0.05 micrograms DHT/dl) but not of dehydroepiandrosterone (DHA; 608 +/- 55) and E2 (6.1 +/- 0.1) were significantly different from those in controls. A negative correlation was observed between SHBG and ABW, both in controls (P less than 0.05) and hirsute patients (P less than 0.01). The hirsute patient population was subdivided into two groups: nonobese (group 2; 60 +/- 1 kg; n = 35) and obese (group 3; 96 +/- 2 kg; n = 22). Plasma androgens, T/SHBG (an index of free T) and E2 in groups 2 and 3 (T: 75 +/- 4, 81 +/- 7; DHT: 24 +/- 2, 28 +/- 3; T/SHBG: 85 +/- 7, 105 +/- 11; delta 4A: 203 +/- 13, 155 +/- 16; DHA: 663 +/- 83, 521 +/- 49; E2: 6.1 +/- 1.0, 5.8 +/- 0.9) were similar; yet SHBG in group 3 (0.75 +/- 0.04) was significantly lower than in group 2 (1.0 +/- 0.01). Inverse correlations between SHBG and ABW, % IBW, and ABW/H2 were observed in group 2 but not in group 3. We conclude that a negative relationship exists between SHBG and the body size in nonobese women and that in hirsute patients, obesity leads to a further lowering of SHBG through mechanism(s) probably independent of androgens.

Dimensions of the pediatric crystalline lens: implications for intraocular lenses in children

As surgeons gain more experience with the implantation of posterior chamber intraocular lenses (IOLs) into the capsular bag in children, the minimum age for which implantation is advised may continue to be lowered. Accurate sizing of an IOL intended for in-the-bag fixation may depend on knowledge of the size of the capsular bag. In order to develop a growth curve for the normal crystalline lens and hence the capsular bag, 50 pediatric autopsy eyes ranging in age from 1 day to 16 years were obtained postmortem and measured within 24 hours after enucleation. Mean crystalline lens diameter was 6.00 mm at birth, 6.80 mm at 2 months, 7.1 mm at 3 months, 7.66 mm at 6 to 9 months, 8.4 mm at 21 months, 8.5 mm at 2 to 5 years, and 9.3 mm at 16 years. The post-lensectomy capsular bag size at each respective age is 1 mm larger. While age was a predictor of crystalline lens size, corneal diameter and globe axial length were better predictors of crystalline lens size. These data and accompanying linear regressions may be helpful in designing appropriate IOLs for pediatric patients.

Sperm immunity in infertile couples: antibody titers are higher against the husbands' sperm than to sperm from controls

Titers of hemagglutination and cytotoxic antibodies to sperm were determined in the sera, seminal plasma, cervical mucus, and vaginal secretions from 69 infertile couples, using sperm from the husbands and from normal control subjects. Titers of hemagglutination and cytotoxic antibodies were significantly higher (p = 0.002 and p less than 0.001, respectively) against autologous sperm as contrasted with sperm from control subjects in sera from 55 autoimmune males. Hemagglutination and cytotoxic antibody titers were also significantly higher (p = 0.044 and p less than 0.001, respectively) against their husbands' sperm as contrasted with control sperm in sera from 46 females with isoimmunity to sperm. Ninety percent of males and females with sperm immunity were positive for histocompatibility antigens HLA-B7, HLA-B8, and/or HLA-BW35. In males, the presence of increased serum cytotoxic antibody titers against autologous versus control sperm was significantly associated with the presence of HLA-B7 allele (p = 0.0017) and with HLA-B7, HLA-B8, and/or HLA-BW35 in general (p less than 0.05). In the females, increased serum antibody titers to their own husbands' versus control sperm were not preferentially associated with HLA-B7, HLA-B8, or HLA-BW35 antigens.

Evidence for renal kinins as mediators of amino acid-induced hyperperfusion and hyperfiltration in the rat

This study examined the role of tissue kallikrein and kinins in renal vasodilation produced by infusion of amino acids (AA). In rats fed a 9% protein diet for 2 wk, intravenous infusion of a 10% AA solution over 60-90 min reduced total renal vascular resistance and increased glomerular filtration rate (GFR) by 25-40% and renal plasma flow (RPF) by 23-30% from baseline. This was associated with a two- to threefold increase in urinary kinin excretion rate. Acute treatment of rats with aprotinin, a kallikrein inhibitor, resulted in deposition of immunoreactive aprotinin in kallikrein-containing connecting tubule cells and inhibited renal kallikrein activity by 90%. A protinin pretreatment abolished the rise in urinary kinins and prevented significant increases in GFR and RPF in response to AA. In a second group of rats pretreated with a B2 kinin receptor antagonist, [DArg Hyp3, Thi5,8 D Phe7]bradykinin, AA infusion raised urinary kinins identically as in untreated controls, but GFR and RPF responses were absent. Aprotinin or the kinin antagonist produced no consistent change in renal function in rats that were not infused with AA.AA-induced increases in kinins were not associated with an increase in renal kallikrein activity. Notably, tissue active kallikrein level fell 50% in AA-infused rats. These studies provide evidence that kinins generated in the kidney participate in mediating renal vasodilation during acute infusion of AA.

Levels of antibodies to transferrin and alpha 2-HS glycoprotein in women with and without endometriosis

PROBLEM

To establish an enzyme-linked immunosorbent assay (ELISA) for determining the levels of antibodies to transferrin and alpha 2-HS glycoprotein in the serum of women with and without endometriosis.

METHOD OF STUDY

Serum samples were obtained from 105 normal women, who were randomly selected for a population-based epidemiologic study, and 123 patients with active endometriosis. An ELISA using transferrin and alpha 2-HS glycoprotein as antigens was established.

RESULTS

The levels of antibodies to transferrin and alpha 2-HS glycoprotein in the serum of patients with endometriosis were approximately 21 times higher than those in the serum of control subjects without endometriosis. Only 2% of control subjects had false positive levels of these antibodies, and 5% of patients with endometriosis had false negative levels of these antibodies (specificity, 98.1 and 98.1, respectively, for anti-transferrin and anti-alpha 2-HS glycoprotein; sensitivity, 95 and 96.7, respectively, for anti-transferrin and anti-alpha 2-HS glycoprotein).

CONCLUSIONS

Patients with endometriosis have significantly higher levels of antibodies to transferrin and alpha 2-HS glycoprotein than control subjects. Testing women for antibodies to transferrin and alpha 2-HS glycoprotein will provide a specific noninvasive diagnosis of endometriosis.

The effect of physician personality on laboratory test ordering for hypertensive patients

Laboratory tests are responsible for a large percentage of health care expenses in the United States. In a retrospective study of the outpatient test ordering by residents for hypertensive patients between the years 1980 and 1986 at the Department of Family Medicine at the Medical University of South Carolina, we found great variability in laboratory test ordering as well as an association between personality as measured by the Myers-Briggs Type Indicator (MBTI) and test ordering. Introverts ordered more than extroverts, and intuitives ordered more than sensors. This association was confirmed by a multiple regression analysis controlling for potential confounders of test ordering, such as severity of disease, the presence of coexisting diabetes mellitus, the demographic characteristics of the patient population, and the number of initial evaluations for hypertension. Elucidation of a relationship between resident personality and laboratory test ordering has important implications for planning intervention strategies to reduce excessive laboratory test ordering in ambulatory care.

The predictive value of posterior pole vessels in retinopathy of prematurity

Dilation and tortuosity of the posterior pole vessels "(plus disease)" is a sign of poor prognosis and may be associated with threshold or prethreshold retinopathy of prematurity (ROP). We have found that normal posterior pole vessels are a reliable marker for the absence of stage 3 ROP. One hundred thirty-two consecutive premature infants weighing less than 1600 g at birth underwent ROP examinations between 32 and 40 weeks' postconceptional age. The status of the posterior pole vessels was compared to peripheral retinal pathology. Vascular findings in the posterior pole were graded 0, 1, 2, or 3, with 0 representing normal arterioles and venules and 3 representing plus disease. The remainder of the fundus examination was recorded using the international Classification of ROP, then converted to a severity scale based on zone and stage of ROP. For each infant, only one examination representing the most severe stage of ROP reached prior to treatment or spontaneous regression was used for data analysis. There was a highly significant Spearman's rank correlation (rs = 0.65) between the posterior pole vascular abnormalities and the severity of ROP in the retinal periphery. Clinically important ROP was not found in any patient with normal posterior pole vessels (grade 0) and stage 3 disease was usually associated with both venous and arterial vascular abnormalities (grades 2 or 3). When ocular examination of premature infants is difficult because of poor dilation of the pupil, hazy media, or medical instability, normal appearance of the posterior pole vessels can be a reassuring finding if it is necessary to postpone complete fundus examination in infants at risk for ROP.

A comparison of the effects of cholesterol on CHD mortality in black and white women: twenty-eight years of follow-up in the Charleston Heart Study

The relationship between cholesterol and 28-year CHD mortality in women was evaluated in the Charleston Heart Study. Linear, quadratic, and cubic models were investigated using Cox proportional hazards regression analysis. In white women, the linear, quadratic, and cubic terms for cholesterol were significant suggesting an asymmetric J-shaped relationship. In black women, only the linear term in all three models was statistically significant suggesting an increasing CHD mortality rate with increasing cholesterol level. The lack of consistency of results by different statistical analyses in black women make conclusions concerning the nature of the relationship between cholesterol and CHD mortality less strong in black women than in white women. Compared with women having a cholesterol value equal to the mean of the group (241 mg/dl), white women having a cholesterol value one standard deviation above the mean (s = 52.5 mg/dl) had a 60% higher CHD mortality rate (hazard ratio = 1.6, 95% CI: 1.2-2.1). In black women, the estimated hazard ratio for a one standard deviation (s = 47.8 mg/dl) increase in cholesterol is 1.4 (95% CI: 1.03-1.8). The results suggest that the relationship of cholesterol to CHD mortality is different in white and black women. The relationship in white women appears to be curvilinear and represented by an asymmetric curve while the relationship in black women is not curvilinear and the overall pattern of association, while possibly linear, is equivocal.

Effects of antibodies to transferrin and alpha 2-HS glycoprotein on in vitro sperm motion: implications in infertility associated with endometriosis

PROBLEM

Women with endometriosis have antibodies to endometrial transferrin and alpha 2-HS glycoprotein in their serum and peritoneal fluid. The objective of this study was to determine whether antibodies to transferrin and alpha 2-HS glycoprotein adversely affect sperm motility and survival.

METHOD OF STUDY

Spermatozoa obtained from normal fertile donors and washed free of seminal plasma were incubated with the medium (control), 1:2 and 1:100 dilutions of antitransferrin, 1:4, 1:8 and 1:100 dilutions of anti-alpha 2-HS glycoprotein, and a 1:2 dilution of antialbumin antiserum (negative control). Sperm motion characteristics in 10 microliters aliquots were evaluated at 30 min, 1 hr, 2 hr, 4 hr, and 24 hr using computerized sperm motion analysis. A paired t-test was done to analyze the effects of the various antibodies on sperm motion characteristics.

RESULTS

Antibodies to albumin failed to adversely affect sperm motility in general or the several sperm motion characteristics in particular. In contrast, antibodies to transferrin at the dilution of 1:2 adversely affected the percentage of motile and rapid spermatozoa, progressive and path velocities, straightness, linearity, track speed, and anterior-lateral head displacement (P < 0.001) at all the time intervals, whereas a 1:100 dilution of this antiserum adversely affected these parameters only at 24 hr. Elongation and beat cross-frequency were significantly affected at 4 and 24 hr by a 1:2 dilution of antitransferrin antiserum. The effects of anti-alpha 2-HS glycoprotein were more pronounced than those of antitransferrin, but they were similar. Dilutions of 1:4 and 1:8 were effective at all time intervals, whereas a 1:100 dilution was effective in reducing the track speed and the percentage of rapid cells at 24 hr (P < 0.001).

CONCLUSION

Antibodies to endometrial transferrin and alpha 2-HS glycoprotein present in the peritoneal fluid, and possibly in the oviductal fluid, of patients with endometriosis may adversely affect postcoital sperm motility and sperm survival.

Black women have smaller abdominal girths than white women of the same relative weight

Anthropometric measurements were compared in 312 white and 242 black women (mean age 54) who were participants in the Charleston Heart Study. Body mass index (BMI) was greater in black women (27.8 kg/m2) than in white women (24.7 kg/m2) as were body circumferences. However, when the girth measurements were adjusted for BMI, some racial differences were reversed. Age, smoking and BMI-adjusted abdominal girth was smaller in the black women than in the white women (88.9 cm vs 92.2 cm). The ratio of abdomen to midarm circumference was larger in white women than black women (3.24 vs 3.09), and could be interpreted to indicate a less central fat pattern in the black women. This conclusion should be viewed with caution since circumference measurements, though often used in epidemiologic research, do not differentiate between subcutaneous fat and visceral fat.

Observer variation in the angiocardiographic diagnosis of mitral valve prolapse

The purpose of this study was to assess the reliability of the angiocardiographic diagnosis of mitral valve prolapse by measuring agreement between observers using defined diagnostic criteria. Sixty high-quality left ventriculograms, selected to include many that showed possible mitral valve prolapse, were reviewed by three angiocardiographers. Disagreement between observers as to positivity occurred in 26 percent and 30 percent of the cases on two reviews, and disagreement as to specific scallop involvement occurred in 68 percent and 78 percent of the cases. A specific observer agreed with himself in interpretation of positive 78 to 82 percent of the time and in the interpretation of specific scallop involvement 55 to 90 percent of the time. These results indicate that in the absence of generally agreed upon quantitative angiocardiographic criteria for the diagnosis of mitral valve prolapse, there is considerable variability among observers in the interpretation of mitral valve prolapse by angiocardiographic studies.