A GAUSS program for computing an index of tracking from longitudinal observations

Tracking can be defined as the tendency of individuals or collections of individuals to stay within a particular course of growth over time relative to other individuals. Thus, tracking describes stability in growth patterns. This paper outlines a statistical procedure for examining tracking in a single sample of measurements made on humans or other animals. This nonparametric procedure, based on Cohen's (1960) kappa statistic, is suitable for equally or unequally spaced serial data that is complete and is appropriate for questions concerning growth as well as other time-dependent phenomena. It is a conceptually simple longitudinal method that affords insight regarding the predictability of growth within a population. For example, by tracking, one can ask if young children who are in the lowest height for age category are likely to end up in that category at an older age. A user-friendly GAUSS program is provided that generates overall as well as individual and track-specific statistics. High-resolution graphic representations of the data are also generated by the program. Examples are presented, including a tracking analysis of Guatemalan Indian children using quartiles.     

Pathologic explanation for postoperative obstipation in Hirschsprung's disease revealed with monoclonal antibody staining

Until now, no pathologic explanation could be found for the postoperative obstipation occurring in some patients with intestinal aganglionosis. Twenty-two of 108 infants treated for intestinal aganglionosis suffered from postoperative obstipation. Resected material from these 22 patients and from 17 control subjects was investigated with monoclonal anti-neurofilament antibody staining. An abnormal staining pattern was revealed in 18 of the constipated patients. Consequently, this new immunohistochemical staining technic has revealed a hitherto unsuspected cause for postoperative obstipation in aganglionosis. The monoclonal antibody may provide early warning of such postoperative constipation.     

Hapten-induced colitis associated with maintained Th1 and inflammatory responses in IFN-gamma receptor-deficient mice

IFN-gamma is a potent pro-inflammatory cytokine thought to be involved in the pathogenesis of Crohn's disease. To further define the role of IFN-gamma in intestinal inflammation, we studied the effects of intra-colonic 2,4,6-trinitrobenzene sulfonic acid (TNBS) instillation in mice with a functionally inactivated IFN-gamma receptor 1 (IFN-gammaR1(- / -)). Our results indicate that IFN-gamma is not necessary for the induction of hapten-induced colitis: after TNBS administration both wild-type and IFN-gammaR1(- / -) mice lost body weight, and the histological features of TNBS-induced colitis were comparable. Colons of IFN-gammaR1(- / -) mice contained a greater number of cells, represented by macrophages and CD4(+) T cells; caudal lymph node cells produced more IFN-gamma and TNF-alpha upon stimulation in vitro. Moreover, IL-18 and IL-12 p40 RNA levels were comparably up-regulated after TNBS treatment in IFN-gammaR1(- / -) wild-type mice. These findings demonstrate that IFN-gamma is dispensable for the development of TNBS-induced colitis. Importantly, the production of Th1 cytokines (e. g. IFN-gamma and TNF-alpha) by caudal lymph node T lymphocytes was enhanced rather than decreased in IFNgammaR1(- / -) mice with no evidence for default Th2 development.     

Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro

The present study was designed to ascertain whether the negative effects on reproductive potential of post-ovulatory ageing in vitro of oocytes can be prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were aged in vitro for 12 h prior to insemination in the presence of varying concentrations of L-ascorbic acid, 6-methoxy- 2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta- mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was associated with lower fertilization rate, higher proportion of concepti exhibiting cellular fragmentation at 24 h post-insemination and lower percentage of concepti reaching the blastocyst stage. Ascorbic acid, Trolox and EDTA had no effect on cellular fragmentation or potential of oocytes for development. However, the probability of an oocyte reaching the blastocyst stage was decreased (P < or = or = 0.05) in oocytes incubated in the presence of L-cystine (50 and 500 microM) and beta-mercaptoethanol (5, 50 and 500 microM) when compared to control aged oocytes. Age-associated cellular fragmentation at 24 h post-insemination was partially prevented (P < or = 0.05) by incubating oocytes in the presence of beta-mercaptoethanol (500 microM). DTT (50 and 500 microM) increased (P < or = 0.05) fertilization rate and number of cells at 81 h post-insemination to levels similar to those exhibited by control oocytes. Furthermore, both age-associated fragmentation at 24 h post-insemination (P < or = 0.05) and decreased potential of oocytes for development to the blastocyst stage (P < or = 0.05) were prevented, at least in part, by culturing oocytes in the presence of DTT (50 microM). Although the mechanism by which DTT exerts its beneficial effects on aged oocytes remains to be elucidated, it may protect oocytes by preventing oxidation of free thiol groups and/or altering a redox-independent signalling pathway that mediates cellular fragmentation and death.      

An investigation of the disclosure process and support needs of BRCA1 and BRCA2 carriers

Disclosure of the results of a positive genetic mutation to offspring can be challenging. The purpose of this study was to investigate the content and process of disclosure from BRCA1/2 carriers to their offspring. A semi-structured questionnaire focused on the disclosure processes between parent and offspring. Thirty-one/40 mothers with BRCA1/2 mutations completed the cross-sectional survey. Sixteen carriers (51.6%) chose to disclose their results to all of their children, thirteen carriers (41.9%) chose not to disclose their results, and two carriers (6.5%) chose to disclose to some of their children. The age of a child appeared to be the most significant contributing factor in the decision to disclose. The mean age of the offspring who learned of the positive test result was 24.3 years with most carriers advocating the ideal age range for disclosure from 19 to 25 years. There was a discrepancy between actual and potential disclosure topics between those who had disclosed and those who had not disclosed at the time of the survey. Women who disclosed their result tended to do so alone, within a week of learning their own results, equally to male and female offspring and expressed that the relationships between themselves and their children had strengthened since revealing the presence of a genetic mutation in the family. Women who had not disclosed the results of their genetic test to offspring were significantly more interested in receiving additional individual counseling, educational videos, and email newsletters that focus on disclosure of this complex and life altering information compared to those who had already disclosed. Disclosure of BRCA1/2 results is determined primarily by age of offspring, is usually done by women alone, relatively soon after receiving results and appears to enhance the relationships between mothers and offspring. Both disclosed and non-disclosed carriers demonstrated significant interest in a variety of interventions to support the disclosure process.     

Aspects of average response computation by aperiodic stimulation

A mathematical analysis of the variance of the average evoked-response computation as a function of the numberN of stimuli presented is made for the case when the response is disturbed by additive stationary noise. A comparison is made between the variance for purely periodic stimuli and that for stimuli of which the interstimulus durations are Gaussian distributed. In the latter situation, the interval durations may be correlated with each other, e.g. according to a Gaussian Markov process. It is deduced that, in general, the introduction of aperiodic stimulation tends to make the functional relationship between the variance andN behave as though it holds for noise with a very broad frequency spectrum; the variance is proportional to 1/N.     

How are different types of continuity achieved? A mixed methods longitudinal study

BACKGROUND: In the context of developments in healthcare services that emphasise swift access to care, concern has been expressed about whether and how continuity of care, particularly interpersonal continuity, will continue to be achieved. AIM: To explore how patients regard and use primary care services in relation to continuity of provider and access to care, to identify factors that promote or hinder their success in achieving their preferences, and to describe what this means for how different types of continuity are achieved. DESIGN OF STUDY: Longitudinal, mixed methods. SETTING: Community in London and Leicester. METHOD: Purposive sample of 31 patients recruited from general practices, walk-in centres and direct advertising. Data collection involved in-depth interviews, consultation record booklets completed over 6 months and general practice records for the year including the study period. Data were analysed qualitatively. RESULTS: Four patterns were identified in the way patients used primary care. These were shaped by their own preferences, by the organisation and culture of their primary care practices, and by their own and their provider's efforts to achieve their preferences. Different configurations of these factors gave rise to different types of continuity. Patients were not always able to achieve the type they wanted. Patients with apparently similar consulting patterns could experience them differently. CONCLUSION: Within a programme of modernisation, policies that promote a commitment to meeting the preferences of different patients with flexibility and understanding are most likely to provide continued support for interpersonal and other types of continuity of care.     

Racial Identity Clusters and Their Relation to Postpartum Maternal Functioning in Black Women

Maternal and Child Health Journal - Racial identity, which is the degree that individuals define themselves regarding their racial group membership, may influence the mental well-being of Black...