Acculturation and the initiation of breastfeeding.

Despite the fact that breastfeeding is the most appropriate form of nutrition for the healthy term infant, the rate of initiation in the U.S. is declining. One demographic factor associated with this low rate is ethnicity and so in this study we measured acculturation (one aspect of ethnicity) into the U.S. and its relationship to the successful initiation of breastfeeding in a sample of women recruited approximately 2 months prenatally in a U.S.-Mexico border city. Interviews were administered in English or Spanish by bilingual interviewers prenatally (n = 906), natally (n = 788), and postnatally (n = 715). Acculturation (measured with a 20 item instrument) was strongly related to the intent to (p < 0.001) or the successful initiation of breastfeeding (p < 0.001). Marital status (p = 0.014) and education (p = 0.002) were related to breastfeeding prenatally and natally. Initiation of breastfeeding was highest among those women least acculturated (52.9%) and lowest in those most acculturated (36.1%) indicating an inhibiting effect of acculturation. To improve the rate of initiation of breastfeeding in the U.S. (a national health goal) intervention programs must consider cultural factors.

Acculturation and breastfeeding on the United States-Mexico border.

Previous studies have demonstrated a strong association between breastfeeding incidence and ethnic background, indicating the presence of strong cultural influences on infant-feeding patterns within ethnic groups. This study analyzed the relationship of acculturation into the United States, one aspect of ethnicity, to the initiation of breastfeeding among a sample of 213 women recruited approximately 2 months prenatally in the United States-Mexico border city of Brownsville, Texas. An in-depth, structured interview was conducted at that time (n = 213), at the time of birth (n = 207), and 2 to 3 weeks postnatally (n = 206). In addition, male partners of the mothers were interviewed prenatally when available (n = 119). Acculturation scores and demographic characteristics were tested relative to breastfeeding initiation. The degree of acculturation, age, and marital status were associated significantly with breastfeeding initiation (with breastfeeding continued at 2 to 3 weeks postnatally), but occupational status, education, and income were not. Breastfeeding incidence was highest among older, married, or low-acculturated, Anglo mothers. These data suggest that women being assimilated into the United States are inhibited in the initiation of breastfeeding. These findings suggest that to be successful, intervention programs to increase breastfeeding incidence must consider the cultural adaptation of different groups as they meld with the larger population.

A study of aspirin induced changes in bleeding time, platelet aggregation, and Sonoclot coagulation analysis in humans.

The purpose of this study was to determine whether or not a newer test of platelet function, Sonoclot coagulation analysis, can identify the patients who develop significant prolongation of bleeding time after aspirin ingestion. Template bleeding time, platelet aggregation in response to arachidonic acid, collagen, epinephrine, adenosine diphosphate, and ristocetin, and Sonoclot coagulation analysis were performed before and after ingestion of aspirin in 22 adult volunteers. Mean bleeding time increased from 5.32 +/- 2.16 min to 7.34 +/- 2.1 min, but remained within normal range (2.5 to 9 min). There was marked intersubject variability in the effect of aspirin on bleeding time, and difference between men and women was not significant. There was significant decrease in platelet aggregation in response to arachidonic acid, collagen and epinephrine. Sonoclot coagulation analysis did not show significant effect of aspirin administration. There was no correlation among changes in bleeding time, platelet aggregation, and Sonoclot coagulation analysis. Five patients with known platelet function disorders and prolonged bleeding times (mean = 18.5 min, range 14 to 22) without any other coagulation abnormalities were also studied. In four of these patients who had normal platelet count, Sonoclot graphs were morphologically similar to those in the volunteers with normal bleeding times, but in one patient with thrombocytopenia, morphology was altered. It is our conclusion that Sonoclot coagulation analysis is unlikely to identify patients with prolonged bleeding time in whom platelet count and other coagulation factors are normal.

Effect of protein/energy ratio on growth and behavior of premature infants: preliminary findings.

Premature infants weighing less than 1550 gm at birth were randomly assigned to receive one of three formulas identical in composition except for protein content (2.2, 2.7, and 3.2 gm.100 kcal-1) to determine the effects on growth, protein nutritional status, and behavior. Data collected for 2 weeks from the time of achieving an enteral energy intake of 100 kcal.kg-1.day-1 included measurements of weight, length, head circumference, and skin-fold thickness, and concentrations of plasma amino acids, serum total protein, prealbumin, retinol-binding protein, and urea nitrogen. In a subset of infants, behavior was assessed at the end of the feeding study with the Neonatal Behavior Assessment Scale. Except for the concentrations of plasma amino acids, there were no significant differences in growth or in other biochemical measurements among the three groups, but there were significant differences in the orientation, habituation, and stability clusters of the behavior assessment. Further, there were significant correlations between the plasma amino acid values and the behavioral clusters. These preliminary data suggest a relationship between protein intake in the neonatal period and behavioral outcome at the end of the feeding period in the absence of differences in growth and gross markers of protein nutritional status. The behavioral items noted to differ among the groups may indicate later cognitive outcome; detailed studies about behavioral responses to neonatal dietary intakes and later outcome seem indicated.

Breast-feeding initiation in a triethnic population.

The influence of sociodemographic factors on the initiation of breast-feeding was evaluated in a triethnic population from Galveston, Tex. Breast-feeding rates were 44.3% among Anglo-Americans, 13.5% among blacks, and 26.6% among Mexican-Americans. Mexican ethnicity, education levels among Anglo-Americans, and marital status were associated with the initiation of breast-feeding. Odds ratios for breast-feeding were 1.94 (95% confidence interval, 1.10 to 3.43) times higher in Mexican-American compared with black women, and 1.94 (95% confidence interval, 1.34 to 2.83) times higher in married than unmarried women. Anglo-American ethnicity and education, as main effects, were not significantly associated with breast-feeding, but their interaction was. Among Anglo-American women (in comparison with black women), the odds ratios of breast-feeding increased with education level, ranging from 1.84 for those with less than an eighth grade education to 7.46 for those with some college. In contrast to recent findings suggesting that education was more important than ethnicity in predicting breast-feeding, the odds of breast-feeding among Anglo-American compared with black women depended on the level of maternal education, but the odds of breast-feeding for Mexican-American vs black women did not depend on education.

Photodeactivation of ethyl violet: a potential hazard of Sodasorb.

Breathing circuit cannisters containing functional CO2 absorbent are critical to prevent rebreathing CO2 during general anesthesia using closed or semiclosed breathing systems. Ethyl violet is the indicator dye added to Sodasorb to indicate impending exhaustion of the absorbent. A case of CO2 rebreathing due to failure of ethyl violet indicator in exhausted Sodasorb was encountered. Laboratory investigation demonstrated that dye failure could result from photodeactivation caused by fluorescent lights. Using a fixed intensity fluorescent light source and quantitative spectrophotometric analysis, a highly significant dose-response relationship was demonstrated between duration of light exposure and the decrease in ethyl violet concentration. After 24 h of fluorescent light exposure with a received flux density of 46 nwatts/cm2 at 254 nm, the concentration of functional ethyl violet remaining in pulverized Sodasorb was 16% of the baseline value. Furthermore, using multiple light sources of various intensities, the greater the intensity of light, the more rapid the rate of decline of the ethyl violet concentration. It is recommended to minimize the problem by using ultraviolet filters and incorporating additional ethyl violet in Sodasorb. Finally, ethyl violet undergoes temporal deactivation after a Sodasorb container is opened, even if it is stored in the dark.

Aberrant baroreceptor mechanotransduction in adult Dahl rats on low-salt diet.

Single fiber, regularly discharging baroreceptors (n = 118) from adult Dahl salt-sensitive (DS) and salt-resistant (DR) rats on a low-salt diet were studied using an in vitro aortic arch-aortic nerve preparation. Pressure thresholds (Pth) and suprathreshold pressure sensitivities (Sth) were determined from responses to slow ramps of pressure. Pressure-diameter relationships measured in each rat were used to transform Pth and Sth values to their mechanical equivalents in terms of aortic wall strain. DS and DR ages were not different (approximately 50 wk). Despite the low-salt diet, DS tail systolic blood pressures were significantly higher than DR by approximately 25 mmHg. Pth averaged 84 mmHg in DR and 97 mmHg in DS. Sth values were similar in DR and DS (average 1.44 and 1.39 spikes.s-1.mmHg-1 in DR and DS, respectively). Increased variance of baroreceptor properties of DS over DR was a prominent finding and necessitated use of nonparametric statistics. The cumulative distribution of Pth values of DS was significantly different from DR, but Sth values were similar. Thus baroreceptor pressure set points are altered in adult DS, but pressure sensitivity per se is not. The differences in pressure parameters were not eliminated by conversion to their mechanical equivalents. Correlation analysis found only weak relationships between Pth and blood pressure for DS and DR (r less than 0.40). Thus in contrast to previous studies in the spontaneously hypertensive rat model, baroreceptors in adult DS on low salt are characterized by elevated variability and a weaker than expected correlation to the prevailing blood pressure in the animal.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the in vitro myocardial depressant effects of isoflurane and halothane anesthesia.

The myocardial depressant effects of isoflurane and halothane were compared using feline right ventricular papillary muscles bathed in Krebs-bicarbonate solution. In experiment 1 muscles were stimulated by field electrodes (0.2 Hz) to obtain control measurements of developed tension (dt) and maximal rate of tension development (dF/dt) prior to exposing the papillary muscles to four concentrations of either isoflurane (4.0%, 2.0%, 1.0%, 0.5%) or halothane (2.0%, 1.0%, 0.5%, 0.25%). Repeat measurements of dt and dF/dt were recorded after 20 min at each concentration. Isoflurane and halothane both caused dose-dependent depression of dt and dF/dt, but at 0.5%, 1.0%, and 2.0%, halothane was significantly more depressant than isoflurane (P less than 0.01 for dt and dF/dt). Quadratic equations were fitted to the dose-response data by least squares analysis (R2 greater than .985 for both anesthetics), and the isoflurane and halothane concentrations that decreased dt to 90%, 70%, 50%, and 30% of control were determined to compare the relative myocardial depressant potency of isoflurane and halothane by linear regression analysis. This potency relationship is described by the equation: isoflurane concentration = -0.005 + 1.445 (halothane concentration). In experiment 2 papillary muscle responses at two similar cardiodepressant concentrations of isoflurane (1.25% and 2.0%) or halothane (0.80% and 1.35%) were compared at stimulus frequencies of 0.05, 0.1, 0.2, 0.4, 0.8, 1.0, and 2.0 Hz. The concentrations of isoflurane and halothane were selected from the data obtained in experiment 1 and represent the anesthetic concentrations that diminish muscle function to approximately 70% and 50% of control.(ABSTRACT TRUNCATED AT 250 WORDS)

An in vitro evaluation of ionized calcium levels and clotting in red blood cells diluted with lactated Ringer's solution.

The addition of lactated Ringer's solution which contains calcium (RL) to citrated blood products poses a potential risk whenever the level of ionized calcium reaches a concentration capable of catalyzing the coagulation cascade. RL solution is used extensively as both a replacement and a maintenance fluid in the operating room. However, major surgical procedures often require replacement of blood components as well, during the operation. This study examines the in vitro propensity for coagulation when red blood cells (RBC) are diluted with RL. Seven mixtures with different ratios of RBC to RL were prepared from each of 23 units of RBC. These mixtures were analyzed for ionized calcium, total calcium, and pH, and were checked for any indication of coagulation. Nineteen additional RBC units were split into two parts which were mixed with equal volumes of normal saline (NS) or RL. These mixtures were filtered (40 micron) and the weight gain of the paired filters compared. From these studies, the authors identified a threshold value for ionized calcium (0.23 mM/L) below which the probability of clot formation is less than 0.01. This concentration is not reached if the RBC to RL volume ratio is 2:1 or greater. As much as 100 ml of RL can be added to a unit of RBC without exceeding the threshold value. Although not advocating the routine use of RL as a diluent for RBC, the authors conclude that, within the guidelines described, calcium containing salt solutions may be used to dilute blood products.

Calcium and magnesium content of skeletal muscle. Studies in subjects undergoing diagnostic testing for malignant hyperthermia.

Ca2+ and Mg2+ contents were measured and compared among three different malignant hyperthermia susceptible (MHS) diagnostic groups. No difference was found among mean values for Ca2+ content, whereas Mg2+ content was greater in MHS muscle. Variance of measured values was unequal and greatest among MHS muscles, suggesting a possible abnormal distribution associated with MHS. Although more muscle fibres with Ca2+ less than or equal to 12 mumol g-1 were observed in MHS muscle, this difference was not statistically significant. In contrast, non-parametric analysis showed that the population of Mg2+ values was significantly greater in the MHS muscle. This study suggests that the distribution of Ca2+ and Mg2+ values is different in MHS muscle as a result of unknown genetic factors associated with the disease.

School promotion of healthful diet and exercise behavior: an integration of organizational change and social learning theory interventions.

In the Go For Health project, interventions based on organizational change and social learning theory facilitate changes in diet and exercise behavior by elementary school children. Baseline data documented the need for behavior change. Based on chemical analyses, average per meal amounts of total fat and sodium were higher than national recommendations: total fat was 29.3% higher than U.S. Dietary Goals; sodium was 107.4% greater than recommended levels. Observations of students in physical education class revealed children moved through space 50.1% of the time and moved continuously an average of 2.2 minutes per class period. These findings suggest the need for policy and practice changes in the school environment to enable children to engage in more healthful diet and exercise behavior.

Attitudes toward breastfeeding.

To understand why some lower socioeconomic status mothers delivering at a state university hospital breastfeed, while others do not, 26 attitude items were administered in a survey of 358 mothers. A factor analysis of these items yielded four interpretable factors: benefits to infant, social inconvenience, personal inconvenience, and physical inconvenience-medical benefits to child. These factors were significantly related to breastfeeding within each level of ethnicity and marital status. The results imply that emphasizing the benefits for the infant, and providing strategies for minimizing personal inconveniences, should promote breastfeeding in these populations.

Immunochemical methods for measurement of transferrin in serum: effects of analytical errors and inappropriate reference intervals on diagnostic utility.

We estimated analytical errors of the Calbiochem, Kallestad, Hyland, Meloy, Helena, and Beckman immunochemical methods for serum transferrin. Intermethod biases were determined by analysis of the "Reference Preparation for Serum Proteins" of the College of American Pathologists and by analysis of 106 patients' serum samples. We judged the acceptability of errors by comparing confidence limits for total errors with 1/4 of the normal reference intervals. The transferrin status of each patient's sample was interpreted by comparing the result of each method with the normal reference interval claimed by the corresponding manufacturer. We found that the combined effects of medically unacceptable analytical errors and inappropriate normal intervals caused results of the tested methods not to be interchangeable. The Calbiochem method identified 61 serum samples (57%) as having abnormally high transferrin concentrations. In contrast, for the same specimen, with the Meloy method we found abnormally high transferrin concentrations for only two samples (1.8%).

The relation of nucleolus diameter to cell body diameter in mammalian dorsal root ganglion cells.

The present study correlates cell body and nucleolar sizes for dorsal root ganglion cells in the rat. To do this, we measured cell body areas and calculated their diameters and measured nucleolar diameters for 719 cells. These data indicate that there is a correlation in that increasing cell size is associated with increasing nucleolar size. However, there is considerable variability of cell body size for each nucleolar diameter and vice versa. Nevertheless, when nucleolar diameters are grouped, the function 1n D = 1.687 + 0.334 dr, where D is the diameter of the cell body and dr the rounded diameter of the nucleolus, produced an almost straight line. Thus this formula provides a good estimate of the relation of nucleolar and cell body sizes for dorsal root ganglion cells of the rat. In addition, estimates of the variances of cell body size at each nucleolar diameter are provided.

Incidence of breast-feeding in a low socioeconomic group of mothers in the United States: ethnic patterns.

Breast-feeding has been shown to have increased in incidence during recent years in the United States. However, this increase is not particularly evident in lower socioeconomic groups. Factors associated with the decision to breast-feed or not were investigated in a population of 379 mothers. Self-completed questionnaires were obtained from 94.5% of these mothers. Data with respect to demographics, reproductive history, prenatal care, and education were collected. Only 27.2% of the study population indicated that they intended to breast-feed. Using the chi2 test for equality of proportions, marital status, head of household, maternal and paternal ethnicity, maternal education, income, and number of pregnancy were found to be the most important variables associated with breast-feeding. The effect of ethnicity predominated over that of the other demographic variables when they were examined jointly within ethnic groups. The effect of ethnicity was apparent when the number of each ethnic group in the study population was compared with the percent of that group that intended to breast-feed: 145 Anglo-Americans, 43.5% breast-feeding; 131 black Americans, 9.2%; 62 Mexican Americans, 22.6%; 19 others, 42.1%. The importance of ethnicity in the decision to breast-feed has probably been underestimated. Efforts to increase breast-feeding in the United States ought to be designed with full consideration of this factor.

Social support, social influence, ethnicity and the breastfeeding decision.

A survey was conducted of all mothers delivering infants at a university medical center hospital in the month of July, 1981. The survey was conducted within 48 hours of delivery and addressed factors related to the breastfeeding decision. The mother's response to the question concerning choice of infant feeding was verified against the feeding records. One set of questions concerned the perceived general supportiveness toward breastfeeding of six individuals significant to the mother. Another set of questions identified who was most influential in the mother's breast or bottle feeding decision. The pattern of significant bivariate relationships between a person's supportiveness and breastfeeding varied across ethnic and maritial status groups. Single and multiple logistic analyses were conducted within ethnic groups to identify from whom support was most important for initiating breastfeeding. Among Black-Americans, support from a close friend was most important. Among Mexican-Americans, support from the mother's mother was most important. Among Anglo-Americans, support from the male partner was important. A broad variety of ensuing research issues are raised. An implication is that social support may be an important interventive variable, but the potentially supportive individual to be reached by an interventive program varies by ethnic group.

Evaluation of determination of glucose in urine with some commercially available dipsticks and tablets.

Four commercial products for urine glucose determination were evaluated and compared with a quantitative hexokinase procedure. We examined precision, sensitivity, and analytical recovery of glucose from glucose-supplemented urine samples and comparison of methods, using patients' samples. Only "Chemstrip uG" (Bio-Dynamics Inc.) could differentiate between 0.3 g/L (upper limit of normal) and 0.6 g/L urine glucose concentrations. "Tes-Tape" (Lilly) and "Diastix" (Ames) gave positive readings at 0.3 g/L; "Clinitest" (Ames) detected glucose only over 1 g/L. Analytical recovery of glucose was best, for all four products, between 1 and 2.5 g/L; Chemstrip uG was the most nearly accurate among the four. Between 5 and 20 g/L glucose concentrations, Tes-Tape, Diastix, and Clinitest tended to give falsely low results; the use of Chemstrip uG resulted in overestimates of concentration at 20 g of glucose per liter. Only Chemistrip uG and Clinitest (two-drop method) had linear ranges extending to 50 g/L; Chemstrip uG had better precision and accuracy at this concentration. Of the four products, Chemstrip uG had the lowest within-technologist and technologist-to-technologist random analytical errors. In method comparison on patients' samples, Chemstrip uG was significantly stronger in its association with the quantitative hexokinase method than was Diastix, Clinitest, or Tes-Tape.