Anatomy of the nail unit and the nail biopsy

The nail unit is the largest and a rather complex skin appendage. It is located on the dorsal aspect of the tips of fingers and toes and has important protective and sensory functions. Development begins in utero between weeks 7 and 8 and is fully formed at birth. For its correct development, a great number of signals are necessary. Anatomically, it consists of 4 epithelial components: the matrix that forms the nail plate; the nail bed that firmly attaches the plate to the distal phalanx; the hyponychium that forms a natural barrier at the physiological point of separation of the nail from the bed; and the eponychium that represents the undersurface of the proximal nail fold which is responsible for the formation of the cuticle. The connective tissue components of the matrix and nail bed dermis are located between the corresponding epithelia and the bone of the distal phalanx. Characteristics of the connective tissue include: a morphogenetic potency for the regeneration of their epithelia; the lateral and proximal nail folds form a distally open frame for the growing nail; and the tip of the digit has rich sensible and sensory innervation. The blood supply is provided by the paired volar and dorsal digital arteries. Veins and lymphatic vessels are less well defined. The microscopic anatomy varies from nail subregion to subregion. Several different biopsy techniques are available for the histopathological evaluation of nail alterations.

Breastfeeding-Associated Hypernatremia: A Systematic Review of the Literature.

There are increasing reports on hypernatremia, a potentially devastating condition, in exclusively breastfed newborn infants. Our purposes were to describe the clinical features of the condition and identify the risk factors for it. We performed a review of the existing literature in the National Library of Medicine database and in the search engine Google Scholar. A total of 115 reports were included in the final analysis. Breastfeeding-associated neonatal hypernatremia was recognized in infants who were ≤ 21 days of age and had ≥ 10% weight loss of birth weight. Cesarean delivery, primiparity, breast anomalies or breastfeeding problems, excessive prepregnancy maternal weight, delayed first breastfeeding, lack of previous breastfeeding experience, and low maternal education level were significantly associated with breastfeeding-associated hypernatremia. In addition to excessive weight loss (≥ 10%), the following clinical findings were observed: poor feeding, poor hydration state, jaundice, excessive body temperature, irritability or lethargy, decreased urine output, and epileptic seizures. In conclusion, the present survey of the literature identifies the following risk factors for breastfeeding-associated neonatal hypernatremia: cesarean delivery, primiparity, breastfeeding problems, excessive maternal body weight, delayed breastfeeding, lack of previous breastfeeding experience, and low maternal education level.

An examination of the relationship between maternal and neighborhood-level characteristics and intrauterine growth retardation in Harris County, Texas, 1999--2001

The persistence of low birth weight and intrauterine growth retardation (IUGR) in the United States has puzzled researchers for decades. Much of the work that has been conducted on adverse birth outcomes has focused on low birth weight in general and not on IUGR. Studies that have examined IUGR specifically thus far have focused primarily on individual-level maternal risk factors. These risk factors have only been able to explain a small portion of the variance in IUGR. Therefore, recent work has begun to focus on community-level risk factors in addition to the individual-level maternal characteristics. This study uses Social Ecology to examine the relationship of individual and community-level risk factors and IUGR. Logistic regression was used to establish an individual-level model based on 155, 856 births recorded in Harris County, TX during 1999-2001. IUGR was characterized using a fetal growth ratio method with race/ethnic and sex specific mean birth weights calculated from national vital records. The spatial distributions of 114,460 birth records spatially located within the City of Houston were examined using choropleth, probability and density maps. Census tracts with higher than expected rates of IUGR and high levels of neighborhood disadvantage were highlighted. Neighborhood disadvantage was constructed using socioeconomic variables from the 2000 U.S. Census. Factor analysis was used to create a unified single measure. Lastly, a random coefficients model was used to examine the relationship between varying levels of community disadvantage, given the set of individual-level risk factors for 152,997 birth records spatially located within Harris County, TX. Neighborhood disadvantage was measured using three different indices adapted from previous work. The findings show that pregnancy-induced hypertension, previous preterm infant, tobacco use and insufficient weight gain have the highest association with IUGR. Neighborhood disadvantage only slightly further increases the risk of IUGR (OR 1.12 to 1.23). Although community level disadvantage only helped to explain a small proportion of the variance of IUGR, it did have a significant impact. This finding suggests that community level risk factors should be included in future work with IUGR and that more work needs to be conducted. ^

Effects of health disparities on Helicobacter pylori infection among children on the US-Mexico border

The objective of this study is to determine whether health disparities influence the odds of developing H. pylori infections among the children enrolled in the Pasitos Cohort Study on the US-Mexico border. The study variables were the number of prenatal care visits, ways of transportation, car in household, location of health services and insurance coverage. The study recruited eligible pregnant women to complete baseline questionnaires. Every six months after the birth of the child, infection status is measure by the 13-C urea breath test. Results indicate that having medical insurance consistently decreases the odds of being infected. Children with mothers who went to a private physician had decreased odds of infection compared to those utilizing public clinics, and having a car in the household increased the odds of infection. Limitations include bias due to loss to follow-up and the transient nature of the infection.^

Probiotics and the prevention of necrotizing enterocolitis in preterm infants: A systematic review of the literature

Necrotizing enterocolitis is a common gastrointestinal disease associated with high mortality and morbidity among preterm infants. This was a systematic literature review that evaluated whether the administration of probiotic supplements is of benefit in the prevention of NEC. The search was narrowed to randomized clinical trials identified through The Cochrane Central Register of Controlled Trials, U.S. National Institute of Health clinical trials registry database, Pub Med and OVID MEDLINE databases. Inclusion criteria were: prospective, randomized clinical trials that administered probiotics as a preventive measure against NEC for infants of early gestational age (<35 wks) and/or low birth weight (<1500g), maintained NEC as the primary measured outcome, used Bell’s classification for NEC diagnosis with reports of stage 2 NEC or higher, and began probiotic administration within 10 days of life. Trials were excluded if participant enrollment was fewer than 100 infants, published before the year 2000, or probiotic supplementation was discontinued after less than seven consecutive days. Based on specific study characteristics, each resulting article was then judged by two authors for study quality. The search was further narrowed to studies of either high or moderate quality, which were then summarized in a set of tables based on study characteristics and results. From an initial set of 20 identified studies, five clinical trials met all criteria; each was discussed thoroughly based on trial limitations, strengths and comparisons to other included publications. Based on this review, the weight of evidence appears to support the use of probiotic supplementation in preterm infants as a preventive measure against NEC. Recommendations for future research were also provided.^

The relationship between premature rupture of the membranes and sepsis in preterm neonates

This investigation was designed as a hospital-based, historical cohort study. The objective of the study was to determine the association between premature rupture of the membranes (PROM) and its duration on neonatal sepsis, infection, and mortality. Neonates born alive with gestational ages between 25 and 35 weeks from singleton pregnancies complicated by PROM were selected. Each of the 507 neonates was matched on gestational age, gender, ethnicity, and month of birth with a neonate without the complication of PROM.^ Data were abstracted from deliveries between January 1979 and December 1985 describing the mother's demographics, labor and delivery treatments and complications, the neonate's demographics, infection status, and medical care. The matched pairs analysis reveals a significant increase in risk of neonatal sepsis (RR = 3.5) and neonatal infection (RR = 2.4) among preterm births complicated by PROM, with a PROM exposure contributing an excess 4 to 5 cases of sepsis per 100 infants (RD = 0.04 for infection and RD = 0.05 for sepsis). Generally PROM remains an important risk factor for sepsis and infection when controlling for various other characteristics, and the risk difference remains constant.^ PROM was not significantly associated with neonatal mortality (RR = 1.02). There is an increase in risk difference for mortality associated with PROM among septic and infected infants, but it is not significant.^ A clear increase in risk of sepsis and infection from PROM occurs when durations of PROM are long (more than 48 hours), e.g., for sepsis the RR is 2.42 for short durations and RR is 6.0 for long durations. No such risk with long duration appears for neonatal mortality.^ This study indicates the importance of close observation of neonates with PROM for sepsis and infection so treatment can be initiated early. However, prematurity is the major risk for sepsis and the practice of early delivery to avoid prolonged durations of PROM does not alter the magnitude of risk. The greatest protection against these infection complications was provided when the neonate weighed over 1500 grams or had more than 33 weeks gestation. ^

The chronobiology of the menstrual life sequence of American women

Seasonal variation in menarche, menstrual cycle length and menopause was investigated using Tremin Trust data. Too, self-reported hot flash data for women with natural and surgically-induced menopause were analyzed for rhythms.^ Menarche data from approximately 600 U.S. women born between 1940 and 1970 revealed a 6-month rhythm (first acrophase in January, double amplitude of 58%M). A notable shift from a December-January peak in menarche for those born in the 1940s and 1950s to an August-September peak for those born in the 1960s was observed. Groups of girls 8-14 and 15-17 yr old at menarche exhibited a seasonal difference in the pattern of menarche occurrence of about 6 months in relation to each other. Girls experiencing menarche during August-October were statistically significantly younger than those experiencing it at other times. Season of birth was not associated with season of menarche.^ The lengths of approximately 150,000 menstrual intervals of U.S. women were analyzed for seasonality. Menstrual intervals possibly disturbed by natural (e.g., childbirth) or other events (e.g., surgery, medication) were excluded. No 6- or 12-month rhythmicities were found for specific interval lengths (14-24, 25-31 and 32-56 days) or ages in relation to menstrual interval (9-11, 12-13, 15-19, 20-24, 25-39, 40-44 and 44 yr old and older).^ Hot flash data of 14 women experiencing natural menopause (NM) and 11 experiencing surgically-induced menopause (SIM) did not differ in frequency of hot flashes. Hot flashes in NM women exhibited 12- and 8-hr, but not 24-hr rhythmicities. Hot flashes in SIM women exhibited 24- and 12-hr, but not 8-hr, rhythmicities. Regardless of type of menopause, women with a peak frequency in hot flashes during the morning (0400 through 0950) were distinguishable from those with such in the evening (1600 through 2159).^ Data from approximately 200 U.S. women revealed a 6-month rhythm in menopause with first peak in May. No significant 12-month variation in menopause was detected by Cosinor analysis. Season of birth and age at menopause were not associated with season of menopause. Age at menopause declined significantly over the years for women born between 1907 and 1926, inclusive. ^

A descriptive study of the sociodemographic, health and developmental factors associated with slow learning in children from upper to middle social class families in Texas

"Slow Learners" is a term used to describe children with an IQ range of 70-89 on a standardized individual intelligence test (i.e. with a standard deviation of either 15 or 16). They have above retarded, but below average intelligence and potential to learn. If the factors associated with the etiology of slow learning in children can be identified, it may be possible to hypothesize causal relationships which can be tested by intervention studies specifically designed to prevent slow learning. If effective, these may ultimately reduce the incidence of school dropouts and their cost to society. To date, there is little information about variables which may be etiologically significant. In an attempt to identify such etiologic factors this study examines the sociodemographic characteristics, prenatal history (hypertension, smoking, infections, medication, vaginal bleeding, etc.), natal history (length of delivery, Apgar score, birth trauma, resuscitation, etc.), neonatal history (infections, seizures, head trauma, etc.), developmental history (health problems, developmental milestones and growth during infancy and early childhood), and family history (educational level of the parents, occupation, history of similar condition in the family, etc.) of a series of children defined as slow learners. The study is limited to children from middle to high socioeconomic families in order to exclude the possible confounding variable of low socioeconomic status, and because a descriptive study of this group has not been previously reported. ^

The use of the computerized and revised vital record in conducting etiologic studies on neural tube defects

The purpose of this study was to evaluate the adequacy of computerized vital records in Texas for conducting etiologic studies on neural tube defects (NTDs), using the revised and expanded National Centers for Health Statistics vital record forms introduced in Texas in 1989.^ Cases of NTDs (anencephaly and spina bifida) among Harris County (Houston) residents were identified from the computerized birth and death records for 1989-1991. The validity of the system was then measured against cases ascertained independently through medical records and death certificates. The computerized system performed poorly in its identification of NTDs, particularly for anencephaly, where the false positive rate was 80% with little or no improvement over the 3-year period. For both NTDs the sensitivity and predictive value positive of the tapes were somewhat higher for Hispanic than non-Hispanic mothers.^ Case control studies were conducted utilizing the tape set and the independently verified data set, using controls selected from the live birth tapes. Findings varied widely between the data sets. For example, the anencephaly odds ratio for Hispanic mothers (vs. non-Hispanic) was 1.91 (CI = 1.38-2.65) for the tape file, but 3.18 (CI = 1.81-5.58) for verified records. The odds ratio for diabetes was elevated for the tape set (OR = 3.33, CI = 1.67-6.66) but not for verified cases (OR = 1.09, CI = 0.24-4.96), among whom few mothers were diabetic. It was concluded that computerized tapes should not be solely relied on for NTD studies.^ Using the verified cases, Hispanic mother was associated with spina bifida, and Hispanic mother, teen mother, and previous pregnancy terminations were associated with anencephaly. Mother's birthplace, education, parity, and diabetes were not significant for either NTD.^ Stratified analyses revealed several notable examples of statistical interaction. For anencephaly, strong interaction was observed between Hispanic origin and trimester of first prenatal care.^ The prevalence was 3.8 per 10,000 live births for anencephaly and 2.0 for spina bifida (5.8 per 10,000 births for the combined categories). ^

A critical assessment of the National Institutes of Health Consensus Development Program against the eras which shaped it

This research study offers a critical assessment of NIH's Consensus Development Program (CDP), focusing upon its historical and valuative bases and its institutionalization in response to social and political forces. The analysis encompasses systems-level, as well as interpersonal factors in the adoption of consensus as the mechanism for resolving scientific controversies in clinical practice application. Further, the evolution of the CDP is also considered from an ecological perspective as a reasoned adaptation by NIH to pressures from its supporters and clients for translating biomedical research into medical practice. The assessment examines federal science policy and institutional designs for the inclusion of the public interest and democratic deliberation.^ The study relies on three distinct approaches to social research. Conventional historical methods were utilized in the interpretation of social and political influences across eras on the evolution of the National Institutes of Health and its response to demands for accountability and relevance through its Consensus Development Program. An embedded single-case study was utilized for an empirical examination of the CDP mechanism through five exemplar conferences. Lastly, a sociohistorical approach was taken to the CDP in order to consider its responsiveness to the values of the eras which created and shaped it. An exploration of organizational behavior with considerations for institutional reform as a response to continuing political and social pressure, it is a study of organizational birth, growth, and response to demands from its environment. The study has explanatory import in its attempt to account for the creation, timing, and form of the CDP, relative to political, institutional, and cultural pressures, and predictive import thorough its historical view which provides a basis for informed speculation on the playing out of tensions between extramural and intermural scientists and the current demands for health care reform. ^

OUT-OF-HOSPITAL CHILDBEARING CENTERS IN THE UNITED STATES: A DESCRIPTIVE STUDY OF THE DEMOGRAPHIC AND MEDICAL-OBSTETRIC CHARACTERISTICS OF WOMEN BEGINNING LABOR THEREIN 1972-1979

There is currently much interest in the appropriate use of obstetrical technology, cost containment and meeting consumers' needs for safe and satisfying maternity care. At the same time, there has been an increase in professionally unattended home births. In response, a new type of service, the out-of-hospital childbearing center (CBC) has been developed which is administratively and structurally separate from the hospital. In the CBC, maternity care is provided by certified nurse-midwives to carefully screened low risk childbearing families in conjunction with physician and hospital back-up.^ It was the purpose of this study to accomplish the following objectives: (1) To describe in a historical prospective study the demographic and medical-obstetric characteristics of patients laboring in eleven selected out-of-hospital childbearing centers in the United States from May 1, 1972, to December 15, 1979. Labor is defined as the onset of regular contractions as determined by the patient. (2) To describe any differences between those patients who require transfer to a back-up hospital and those who do not. (3) To describe administrative and service characteristics of eleven selected out-of-hospital childbearing centers in the United States. (4) To compare the demographic and medical-obstetric characteristics of women laboring in eleven selected out-of-hospital childbearing centers with a national sample of women of similar obstetric risk who according to birth certificates delivered legitimate infants in a hospital setting in the United States in 1972.^ Research concerning CBCs and supportive to the development of CBCs including studies which identified factors associated with fetal and perinatal morbidity and mortality, obstetrical risk screening, and the progress of technological development in obstetrics were reviewed. Information concerning the organization and delivery of care at each selected CBC was also collected and analyzed.^ A stratified, systematic sample of 1938 low risk women who began labor in a selected CBC were included in the study. These women were not unlike those described previously in small single center studies reported in the literature. The mean age was 25 years. Sixty-three per cent were white, 34 per cent Hispanic, 88 per cent married, 45 per cent had completed at least two years of college, nearly one-third were professionals and over a third were housewives. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of school.) UMI ^

2005 ACIP recommendations effect on newborn hepatitis B vaccination rates and the factors affecting the successful implementation of the recommendations in the US

Background. Hepatitis B virus infection is one of major causes of acute and chronic hepatitis, cirrhosis of the liver, and primary hepatocellular carcinoma. Hepatitis B and its long term consequences are major health problems in the United States. Hepatitis B virus can be vertically transmitted from mother to infant during birth. Hepatitis B vaccination at birth is the most effective measure to prevent the newborn from HBV infection and its consequences, and is part of any robust perinatal hepatitis B prevention program following ACIP recommendations. Universal vaccination of the new born will prevent HBV infection during early childhood and, assuming that children receive the three dosages of the vaccine, it will also prevent adolescent and adult infections. Hepatitis B vaccination is now recommended as part of a comprehensive strategy to eliminate HBV transmission in the United States. ^ Objective. (1)To assess if the hepatitis B vaccination rates of newborn babies have improved after the 2005 ACIP recommendations. (2) To identify factors that affects the implementation of ACIP recommendation for hepatitis B vaccination in newborn babies. These factors will encourage ongoing improvement by identifying successful efforts and pinpointing areas that fall short and need attention. Additional focus areas may be identified to accelerate progress in eliminating perinatal HBV transmission.^ Methods. This review includes information from all pertinent articles, reviews, National immunization survey (NIS) surveys, reports, peer reviewed literature and web sources that were published after 1991.The key words to be used for selecting the articles are: "Perinatal Hepatitis B Prevention program", "Universal Hepatitis B vaccination of newborn babies", "ACIP Recommendations." The data gathered will be supplemented with an analysis of vaccination rates using the National Immunization Survey (NIS) birth dose coverage data.^ Results. The data collected in the NIS of 2009 reveals that the national coverage for birth dose of HepB increased to 60.8% from 50.1% in 2006. The largest increase observed for the birth dose in the past 5 years is from 2008 which increased from 55.3 % to 60.8% in 2009. By state, coverage ranged from 22.8% in Vermont to 80.7% in Michigan. %. Overall, in 2009 the estimated vaccination rates are in higher ranges for most states compared to the estimated vaccination rates in 2006. States vary widely in hepatitis B vaccination rates and in their compliance with the 2005 ACIP recommendation. There are many factors at various stages that might affect the successful implementation of the new ACIP recommendation as revealed in literature review. ^ Conclusions. HBV perinatal transmission can be eliminated, but it requires identifying the gaps and measures taken to increase the current vaccination coverage, ensuring timely administration of post exposure immunoprophylaxis and continued evaluations of the impact of immunization recommendations.^

A study of the association between timing of solid food introduction in infants and overweight and obesity in pre-school aged children in NHANES 2003-2008

Background. Previous studies suggest an association between timing of introduction of solid food and increased risk of obesity in pre-school aged children, but no study included a representative sample of US children. We sought to examine whether there was any association between the timing of solid food introduction and overweight/obesity in pre-school aged children. Design/methods. Cross-sectional study of a nationally representative sample (N=2050) of US children aged 2 to 5 years with information on infant feeding practices and measured weight and height from the National Health and Nutrition Examination Survey 2003–2008. The main outcome measure was BMI for age and sex ≥ 85th percentile. The main exposure was timing of solid food introduction at < 4, 4–5, or ≥ 6 months of age. Binomial logistic regression was used in the analysis controlling for child's sex, birth weight and breastfeeding status as well as maternal age at birth, smoking status and socio-demographic variables. Results. Two thousand and fifty children were included in the sample; 51% male and 49% female; 57.1% Non-Hispanic White, 21.9% Hispanic, 14.0% Non-Hispanic Black, and 7% other race/ethnicity. Twenty-two percent of the children were overweight or obese. Sixty-nine percent were breastfed or fed breast milk at birth and 36% continued breastfeeding for ≥ six months. Solid foods were introduced before 4 months of age for 11.2% of the children; 30.3% received solid foods between 4 to 5 months; with 58.6% receiving solid foods at 6 months or later. Timing of solid food introduction was not associated with weight status (OR= 1.36, 95% CI [0.83–2.24]). Formula-fed infants and infants breastfed for < 4 months had increased odds of overweight and obesity (OR=1.54, 95% CI [1.05–2.27] and OR= 1.60, 95% CI [1.05–2.44], respectively) when compared to infants breastfed for ≥ 6 months. Conclusion. Timing of solid food introduction was not associated with weight status in a national sample of US children ages 2 to 5 years. More focus should be placed on promoting breastfeeding and healthy infant feeding practices as strategies to prevent obesity in children. ^

Behavioral decision making and the levels of change: An application of the transtheoretical model to prenatal smoking in low -income women

Despite continued research and public health efforts to reduce smoking during pregnancy, prenatal cessation rates in the United States have decreased and the incidence of low birth weight has increased from 1985 to 1991. Lower socioeconomic status women who are at increased risk for poor pregnancy outcomes may be resistant to current intervention efforts during pregnancy. The purpose of this dissertation was to investigate the determinants of continued smoking and quitting among low-income pregnant women.^ Using data from cross-sectional surveys of 323 low-income pregnant smokers, the first study developed and tested measures of the pros and cons of smoking during pregnancy. The original decisional balance measure for smoking was compared with a new measure that added items thought to be more salient to the target population. Confirmatory factor analysis using structural equation modeling showed neither the original nor new measure fit the data adequately. Using behavioral science theory, content from interviews with the population, and statistical evidence, two 7-item scales representing the pros and cons were developed from a portion (n = 215) of the sample and successfully cross-validated on the remainder of the sample (n = 108). Logistic regression found only pros were significantly associated with continued smoking. In a discriminant function analysis, stage of change was significantly associated with pros and cons of smoking.^ The second study examined the structural relationships between psychosocial constructs representing some of the levels of and the pros and cons of smoking. The cross-sectional design mandates that statements made regarding prediction do not prove causation or directionality from the data or methods analysis. Structural equation modeling found the following: more stressors and family criticism were significantly more predictive of negative affect than social support; a bi-directional relationship was found between negative affect and current nicotine addiction; and negative affect, addiction, stressors, and family criticism were significant predictors of pros of smoking.^ The findings imply reversing the trend of decreasing smoking cessation during pregnancy may require supplementing current interventions for this population of pregnant smokers with programs addressing nicotine addiction, negative affect, and other psychosocial factors such as family functioning and stressors. ^

Geochemistry of volcanic glass from ODP holes 129-801C and 185-801C in the western Pacific

Major element chemistry of basalt from the southern East Pacific Rise (EPR) is different from that of the EPR at the time of the formation of the Pacific Plate at 170 Ma.Glass recovered from Jurassic age (170 Ma) Pacific ocean crust (Bartolini and Larson, 2001, doi:10.1130/0091-7613(2001)029<0735:PMATPS>2.0.CO;2) at Ocean Drilling Program Hole 801C records higher Fe8 (10.77 wt%) and marginally lower Na8 (2.21 wt%) compared to the modern EPR, suggesting deeper melting and a temperature of initial melting that was 60°C hotter than today.Trace element ratios such as La/Sm and Zr/Y, on the other hand, show remarkable similarities to the modern southern EPR, indicating that Site 801 was not generated on a hotspot-influenced ridge and that mantle composition has changed little in the Pacific over the past 170 Ma. Our results are consistent with the observation that mid-ocean ridge basalts (MORBs) older than 80 Ma were derived by higher temperature melting than are modern MORBs (Humler et al., 1999, doi:10.1016/S0012-821X(99)00218-6), which may have been a consequence of the Cretaceous superplume event in the Pacific.Site 801 predates the formation of Pacific oceanic plateaus and 801C basalt chemistry indicates that higher temperatures of mantle melting beneath Pacific ridges preceded the initiation of the superplume.