Cyclic seasonal variation in plasma lipid and lipoprotein levels: the Lipid Research Clinics Coronary Primary Prevention Trial Placebo Group.

Seasonal plasma lipid and lipoprotein cycles were studied in 1446 hypercholesterolemic 35-59 year-old men followed for 7 years as the placebo group of the Lipid Research Clinics (LRC) Coronary Primary Prevention Trial (CPPT). Separate periodic time series were calculated for each study participant; mean parameter estimates were obtained by vector algebra. Highly significant (p less than 0.001) synchronous sinusoidal seasonal cycles, peaking in the first month of winter, were demonstrated for plasma levels of total (TOT-C), low-density lipoprotein (LDL-C), and high-density lipoprotein (HDL-C) cholesterol. Their mean seasonal changes (nadir to zenith) were 7.4, 6.4, and 0.8 mg/dl, respectively. An irregular but statistically significant seasonal pattern was also observed for plasma triglyceride (TG) levels, with peak levels in the autumn. The variation of these seasonal effects among subgroups and geographic locales and their correlation with seasonal weight and dietary patterns yielded few clues as to their underlying etiologic mechanisms.

Seasonal cholesterol cycles: the Lipid Research Clinics Coronary Primary Prevention Trial placebo group.

Seasonal variation of plasma cholesterol levels was studied in 1446 hypercholesterolemic 35- to 59-year-old male participants in the Lipid Research Clinics Coronary Primary Prevention Trial placebo group. Each man's serial cholesterol data, obtained at bimonthly intervals for 2.0 to 6.5 years, were analyzed as a separate periodic time series, and distributions of cycle zeniths and amplitudes were calculated. A highly significant (chi 2= 706, 2 degrees of freedom) seasonal effect, 7.4 mg/dl higher on December 30 than on June 30, was found. This effect was similar among the 12 LRC centers, including such disparate climates as those of Minneapolis and San Diego, and tended to be larger in the southern centers. Its magnitude was independent of baseline levels of plasma cholesterol and other baseline characteristics. Observed seasonal differences in weight and diet explained less than one-third of the seasonal variation in plasma cholesterol levels. Plasma low- and high-density lipoprotein cholesterol levels, analyzed similarly, also showed significant synchronous seasonal cycles. Plasma triglyceride levels showed a weaker irregular seasonal pattern, highest in midsummer and late autumn and lowest in spring. The etiologies and mechanisms for these seasonal patterns remain largely unknown.

The relationship of histologic and clinical factors in laryngeal papillomatosis.

Laryngeal papillomatosis is a disease that can lead to many surgical procedures, especially in children, and is potentially lethal. In this study, we reviewed 83 cases that yielded 902 separate laryngoscopy specimens to determine if any clinical or histologic findings were prognostic. "Juvenile" (n = 73) and "adult" (n = 10) cases were classified according to the number of separate lesions and the number of recurrences, but not necessarily according to age. Four prognostic indicators were constructed for the juvenile group and were analyzed by linear regression. Three new microscopic classifications were used: papillary, acanthomatous, and angiokeratotic. In juvenile cases, the last two categories appeared to be somewhat prognostic, along with several other factors. Some histopathologic findings contradicted classic descriptions. Differences in clinical manifestation and similarities in histopathology may suggest differential responses to the same causal agent.

Endometrial papillary adenocarcinomas: two clinicopathological types.

Thirty-four patients with primary endometrial papillary adenocarcinoma diagnosed in our institution from 1970 to 1982 were studied. Papillary adenocarcinomas represented 10% of all endometrial adenocarcinomas seen during this period. Papillary neoplasms were morphologically subclassified as either papillary serous adenocarcinoma or well-differentiated papillary adenocarcinoma, following review of the histological sections obtained prior to radiotherapy or chemotherapy. Twenty-five patients were found to have papillary serous adenocarcinoma, and nine had well-differentiated papillary adenocarcinoma. A control group of 305 patients with endometrial adenocarcinoma of nonpapillary type was compared with respect to age, race, and survival. Fifty percent of the patients with papillary serous adenocarcinoma were black and they were significantly older (p = 0.001) than the control group, with a mean age of 71 years. Thirty percent of the papillary serous adenocarcinoma group had deep myometrial invasion and peritoneal surface involvement by tumor. In 20% of these patients there was a discrepancy between the clinical stage and the surgical stage at laparotomy. Survival was markedly worse (p = 0.01) than that of the control group. Patients with well-differentiated papillary adenocarcinomas were similar to control patients with respect to age and racial status and had similar clinical survival outcome. We conclude that well-differentiated papillary adenocarcinoma of the endometrium is a distinct form of papillary adenocarcinoma, and must be morphologically and clinically distinguished from papillary serous adenocarcinomas because of its better prognosis. Morphological differentiation of these two papillary variants of endometrial adenocarcinoma is presented.

Correlates of low density lipoprotein cholesterol: associations with physical, chemical, dietary, and behavioral characteristics.

The purpose of this cross-sectional study was to describe the relationship between low density lipoprotein cholesterol (LDL-C) and various physical, chemical, dietary, and behavioral attributes of 4768 white men and women aged 20-59 years from 10 North American populations sampled by the Lipid Research Clinics Program. For our analyses, women were separated into two groups: users and nonusers of hormones. A positive correlation coefficient between very low density lipoprotein cholesterol (VLDL-C) and LDL-C was observed for women but not for men. Fasting plasma concentrations of LDL-C were most strongly and consistently associated in each gender with age, the Quetelet Index of body mass, the number of cigarettes smoked per day, systolic blood pressure, and the levels of plasma glucose and uric acid (all positive associations); and with height and bilirubin levels (both negative associations). Gender-related differences were found in the associations between LDL-C and the other lipids and lipoprotein cholesterol fractions measured. The associations between LDL-C and individual nutrients computed from a 24-hour dietary recall were generally of a low-order magnitude. The strongest and most consistent among the statistically significant associations were those between LDL-C and total caloric intake and with carbohydrates and sucrose (all negative associations). Other statistically significant association between LDL-C and reported intake of nutrients were less consistent, e.g., LDL-C levels were negatively related to alcohol consumption in women, but showed a weak positive relation to alcohol intake in men. Multiple linear stepwise regression was used to assess the variation in LDL-C concentration attributable to each characteristic under study, adjusted for concomitant variation in any other variable. As in the univariable analyses, age was the strongest covariate of LDL-C; adjusting for all other terms in the stepwise regression analysis, cigarette smoking was identified as the next strongest determinant of LDL-C. Other measurements, such as body mass, clinical chemistries, and alcohol consumption, emerged as independent predictors of LDL-C levels in a pattern specific to gender and to hormone use.

Determinants of foster care placement for the maltreated child.

This study examined the records of the North Carolina Central Registry of Child Abuse and Neglect to determine which social, family, and child characteristics were most influential in the decision to place a child in foster care. These records contained all theoretically relevant factors as well as demographic data. Analysis included the computation of odds ratios for foster care for each of 250 variables. A maximum likelihood logistic regression model was constructed to obtain the independent and cumulative contribution of each factor. Some expected variables such as parental stress factors (substance abuse) and types of abuse (burns and scalds) placed a child at a significant risk for placement in foster care (p less than 0.01). However, less obvious factors such as referral source (law enforcement agencies) or geographic area also placed children at risk. Overall, the model explained little of the variance of these decisions (R2 = 0.168) and poorly predicted placement (sensitivity 66.3 per cent, specificity 74.6 per cent). Using existing data, we were unable to adequately describe the decision process in selecting foster care.

Determinants of foster care placement for the maltreated child.

This study examined the records of the North Carolina Central Registry of Child Abuse and Neglect to determine which social, family, and child characteristics were most influential in the decision to place a child in foster care. These records contained all theoretically relevant factors as well as demographic data. Analysis included the computation of odds ratios for foster care for each of 250 variables. A maximum likelihood logistic regression model was constructed to obtain the independent and cumulative contribution of each factor. Some expected variables such as parental stress factors (substance abuse) and types of abuse (burns and scalds) placed a child at a significant risk for placement in foster care (p less than 0.01). However, less obvious factors such as referral source (law enforcement agencies) or geographic area also placed children at risk. Overall, the model explained little of the variance of these decisions (R2 = 0.168) and poorly predicted placement (sensitivity 66.3 per cent, specificity 74.6 per cent). Using existing data, we were unable to adequately describe the decision process in selecting foster care.

Plasma high-density lipoprotein cholesterol in children and young adults. The Lipid Research Clinics Program Prevalence Study.

We examined the decline in high-density lipoprotein cholesterol in adolescent males and the postadolescent sex differences in HDL cholesterol levels. Prevalence data are presented for 1639 white males and females ages 6-25 years from six populations of the Lipid Research Clinics Program. The association of HDL cholesterol with age, smoking habits, and anthropometric, clinical chemistry and nutritional variables was examined by correlation and regression analyses. Although mean HDL cholesterol levels in children ages 6-10 years were lower in females than in males, HDL cholesterol levels gradually increased with age in females, while in males the mean HDL cholesterol levels declined form 55.9 mg/dl at ages 6-10 years to 45.5 mg/dl at ages 18-25 years. In young adults, HDL cholesterol levels were an average of 10.5 mg/dl higher in females than in males. In the 6-10-year-old age group, none of the study variables was significantly associated with HDL cholesterol. In the 11-17-year-old subjects, significant associations were noted with several variables, especially in the males. The strongest association was an inverse association with weight in males. In the young adults ages 18-25 years, significant inverse associations were found with weight and alkaline phosphatase in both sexes and with sucrose and smoking in females. The data suggested that the most important influence on HDL cholesterol levels in adolescent males are changes in gonadal hormone levels and that some of the factors known to influence HDL cholesterol levels in older adults are already associated with HDL cholesterol in adolescents and young adults.

Quantification of visual fields for statistical analysis.

The importance of visual fields in the study of ocular vascular disorders prompted the development of a method to convert visual fields plotted on a Goldmann perimeter into a digital form so that the data could be analyzed and stored by a computer. An instrument called a scotometer was designed to measure the visual fields and the various scotomata, and a data coding form was developed to facilitate the entry of the data into the computer. After extensive testing, this method is now being used in several clinical trials. Statistics have been computed that support the reliability of the coding process.

Therapeutic use of albumin.

Increasing use of normal human serum albumin may be contributing to the rising cost of medical care. To investigate whether albumin is extensively overused or abused, a study of the quality of albumin use was conducted in a Veterans Administration Hospital. Specific criteria for appropriate use were developed using guidelines defined at a national symposium. A review of use during a three-month period showed that surgery patients received 91% of the albumin administered during that period; of the total amount administered, 41% was used inappropriately; the decision to administer albumin to patients undergoing surgery appeared to be correct only 29% of the time; and an estimated $40,000 was spent on inappropriately used albumin at this hospital in 1977.