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Results for “Developmental programming”

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At least 235 records · Page 13Linked to original sources
PubMed1998

Selective treatment program for developmental dysplasia of the hip in an epidemiologic prospective study.

Over 1 year of ultrasound (US) mass screening, 4,568 newborns were examined consecutively at age 3-4 weeks using both clinical and ultrasonographic examination methods. The US examination involved both the static and dynamic scanning. In total, 25 babies were treated early (5.5 per 1,000), and 6 babies were given late treatment for postnatally developing acetabular dysplasia (1.3 per 1,000). Early treatment was instituted only for hips remarkably distorted anatomically, as could be seen from their shape on the static scan, and for those that were sonographically unstable with an apparent stress displacement. Clinical examination at age 3-4 weeks failed in more than half of all sonographically abnormal cases. In one case, the postnatal development of the hip joint was associated with the worsening of its formation and a developing subluxation despite its primary normal characteristics.

Czech Republic↗
PubMedDate not supplied

Concept of the developmental education program model.

The need to assist minority students to succeed in baccalaureate nursing programs has been well documented in the literature. Described in this article is a model framework to assist schools of nursing in developing comprehensive integrated programs for student development and retention.

Education, Nursing, Baccalaureate↗
PubMed1979

Allied health careers special resources and services program: increasing the probabilities of success for 'high risk' students in allied health career programs.

This article describes a successful developmental program specifically designed for academically "high risk" students entering a two-year community college career program in allied health. The program consisted of providing an intensive three-week instructional program to students before they entered the allied health career program, and subsequently providing an ongoing support system of tutoring, counseling and career development activities. Participants attained higher levels of academic performance and retention than nonparticipants.

Achievement↗
PubMed1992

Compartmentalized transcription and the establishment of cell type during sporulation in Bacillus subtilis.

An early step in sporulation of the bacterium Bacillus subtilis, is the formation of two compartments in the developing sporangium: the mother cell and the forespore. These compartments differ in their programs of gene expression and developmental fate. The establishment of cell type within this simple developmental program, is accomplished by the compartmentalization of sigma subunits of RNA polymerase. The localization of these sigma factors results in compartment-specific gene expression. Recent experiments have elucidated some of the early steps in the establishment of cell type. After septum formation, the activity of the sigma factor, sigma F, is confined to the forespore compartment. This, in turn, results in the localized expression of another developmental sigma factor, sigma G. The forespore localization of these two sigma factors, establishes the forespore line of gene expression. sigma F and sigma G also regulate mother cell events. sigma F activity in the forespore regulates the proteolytic processing of sigma E within the mother cell compartment. The localization sigma E activity leads to mother cell expression of another sigma factor, pro-sigma K. The proteolytic processing of pro-sigma K to mature sigma K is controlled by the forespore sigma factor, sigma G. Mature sigma K then directs the transcription of mother cell specific genes. Therefore, the initial localization of sigma F activity to the forespore compartment, orchestrates the establishment of cell type in both forespore and mother cell compartments.

Bacillus subtilis↗
PubMed2001

ngl9: a third MADS box gene expressed in alfalfa root nodules.

Expression of MADS box genes has previously been localized to the infected cells of alfalfa (Medicago sativa) root nodules. These genes represent the first putative transcription factors to be identified in nodules and are hypothesized to be involved in a signal transduction pathway initiated by the intracellular bacterium. The eventual activation of specific target genes defines pertinent characteristics of this nitrogen-fixing differentiated cell. In this study, we identify a third nodule MADS box gene, ngl9, and demonstrate that the DNA-binding activity of its protein product is dependent on the presence of a second MADS box protein, NMH7. Despite previous results to the contrary, both genes are expressed in the early stages of flower development, further strengthening the premise that nodule developmental programming may capitalize upon existing developmental cascades.

Amino Acid Sequence↗
PubMed1999

Developmental care teams in the neonatal intensive care unit: survey on current status.

Developmental Care Teams (DCT) have evolved in Neonatal Intensive Care Units (NICUs) in response to mounting evidence that developmental care is cost-effective and improves outcomes of critically ill newborns. Lack of national practice guidelines and standardized roles for DCT members prompted formulation and distribution of a questionnaire to obtain information regarding staff membership of DCTs, budgeting for DCTs, utilization of developmental care in practice, and education and developmental training of NICU staff. Questionnaires were sent to 50 NICUs in 30 states, with a return rate of 62% (31 of 50), representing 18 different states. Of those who responded, 64% had a DCT, and an additional 24% were in various phases of starting a team. Forty-three percent of the teams meeting on a regular basis did so monthly. Only 30% of those with a DCT had a dedicated budget to cover operating costs of their developmental program. Fifty-two percent of respondents had Neonatal Individualized Developmental Care and Assessment Program (NIDCAP)-certified staff at their institutions; however, nine other types of developmental specialists were also listed. Only four respondents indicated utilization of set criteria for initiation of a DCT consult, and 74% of those with DCTs initiated consults "when the need arises." NIDCAP assessments were used for parent teaching (54%), care plans (69%), care recommendations (46%), and at caregiver "discretion" (39%). The results of the survey validated an intense interest in developmental care. Approach to developmental care is variable between NICUs and implementation as outlined by NIDCAP is unusual. Practical guidelines for utilization and funding of DCTs are needed.

Child Development↗
PubMed1997

A mutational analysis of conjugation in Tetrahymena thermophila. 1. Phenotypes affecting early development: meiosis to nuclear selection.

Conjugation in the freshwater ciliate Tetrahymena thermophila involves a developmental program that models meiosis, fertilization, and early developmental events characteristic of multicellular eukaryotes. We describe a gallery of five early-acting conjugation mutations. These mutants, cnj1-5, exhibit phenotypes in which specific steps in the conjugal pathway have been altered or eliminated. Specifically, cnj1 and cnj2 fail to condense their micronuclear chromatin prior to each of the three prezygotic nuclear divisions. This results in nuclear division failure, failure to replicate DNA, and failure to initiate postzygotic development. The cnj3 mutant appears to exhibit a defect in chromosome separation during anaphase of mitosis. cnj4 mutants successfully carry out meiosis I, yet are unable to execute the second meiotic division and abort all further development. cnj5 mutants are unable to initiate either meiosis I or meiosis II, yet proceed to execute all subsequent developmental events. These mutant phenotypes are used to draw inferences regarding developmental dependencies that exist within the conjugation program.

Animals↗
PubMed1983

A new method for examining the complexity and relationships of "timers" in developing systems.

Simple methods are developed for analyzing the rate-limiting pathways, or "developmental timers," for consecutive stages in a developing system. Two conditions are first defined for short and long timing to a developmental stage. Shifts are then performed at time intervals from short to long and long to short conditions. The total time to the stage (time under first condition plus time under second condition) is scored and plotted as a function of the time of shift, resulting in two plots, one for shifts from the short to long condition, and the other for shifts from the long to short condition. Each plot is then analyzed for the number of components, slopes of components, absolute times of origins and termini of components, and discontinuities between components. This information is then used (1) to distinguish between single- and multiple-component timers, (2) to assess the sensitivity of each timer component to the change in the environmental condition employed in the method, including reversibility, (3) to test for the addition of a new timer component under long conditions, and (4) to test for an identity change of a timer component between short and long conditions. These interpretations in turn provide a minimum estimate of the complexity of the rate-limiting pathway to a developmental stage, temporally define major transition points between timer components, and provide some insight into the nature of timer components. By characterizing the rate-limiting pathway from the origin of a developmental program for each consecutive stage in that program, distinctions can also be made between single, parallel, sequential, and branching timer relationships. From these interpretations, a detailed temporal "map" of the rate-limiting program can be generated for any developmental system in which consecutive stages can be reproducibly monitored with time.

Animals↗
PubMed1997

Gravity, light and plant form.

Plants have evolved highly sensitive and selective mechanisms that detect and respond to various aspects of their environment. As a plant develops, it integrates the environmental information perceived by all of its sensory systems and adapts its growth to the prevailing environmental conditions. Light is of critical importance because plants depend on it for energy and, thus, survival. The quantity, quality and direction of light are perceived by several different photosensory systems that together regulate nearly all stages of plant development, presumably in order to maintain photosynthetic efficiency. Gravity provides an almost constant stimulus that is the source of critical spatial information about its surroundings and provides important cues for orientating plant growth. Gravity plays a particularly important role during the early stages of seedling growth by stimulating a negative gravitropic response in the primary shoot that orientates it towards the source of light, and a positive gravitropic response in the primary root that causes it to grow down into the soil, providing support and nutrient acquisition. Gravity also influences plant form during later stages of development through its effect on lateral organs and supporting structures. Thus, the final form of a plant depends on the cumulative effects of light, gravity and other environmental sensory inputs on endogenous developmental programs. This article is focused on developmental interactions modulated by light and gravity.

Arabidopsis↗
PubMed2002

[Evaluation of the developing human visual system using flash-visual evoked potential].

Flash visual evoked potential (Flash-VEP) is easily recorded in preterm infants. However, its clinical application has not been established due to its great variability in response. Our longitudinal studies on the two components of the N1 wave facilitated peak definition and established normal ranges that are clinically valuable. The N1a (early component of the N1) peak latency decreases at about 4.6 msec/week between 30 and 40 weeks postmenstrual age. A flash-VEP study in the preterm period enables us to observe the neuronal development in the human visual system that normally proceeds in utero. Flash-VEP analyses on preterm infants demonstrated that the decrease in the N1a peak latency reflects the progress of myelination in the visual pathway according to the developmental program irrespective of preterm birth. The developmental changes of the N1 wave configuration reflect the maturation of the neuronal networks in the visual cortex, which is accelerated by extrauterine visual experience. Using improved methodology and peak denomination that we proposed, flash-VEP can be applied to preterm infants safely, and should provide us with neuro-developmental information of the human cerebrum.

Cerebral Hemorrhage↗
PubMed1999

Apoptosis and predisposition to oral cancer.

The term apoptosis, also known as programmed cell death (PCD), was coined by developmental biologists a number of years ago to describe a form of cell death characterized by several unique morphological and biochemical features. Genetic studies of the round worm Caeneorhabditis elegans, a simple multicellular organism, first revealed apoptosis to be an integral part of the developmental program. Subsequently, the importance of apoptosis in higher organisms was demonstrated in several eukaryotic systems. [n mammals, apoptosis is widespread during embryogenesis and in adult tissues. It is required for normal tissue homeostasis and for clonal selection in the immune system. In both developing and adult organisms, apoptosis plays a central role in reinforcing appropriate cellular patterns and in regulating cell number by eliminating cells that are harmful or no longer needed. It is becoming increasingly clear that disruption in the apoptosis pathway can contribute to the development of a number of developmental, inflammatory, degenerative, and neoplastic diseases. The effector arm of the apoptotic program includes members of the Bcl-2 gene family that function as either death agonists or death antagonists. These proteins participate in an elaborate genetically controlled biochemical pathway that functions to maintain tissue and organ homeostasis and serve as a critical defense mechanism to guard against malignant transformation. Cancer is the result of a series of genetic lesions that include activation of oncogenes and inactivation or loss of tumor suppressor genes. Several groups of investigators have observed that deregulated expression of oncogenes can subvert apoptotic pathways, resulting in prolonged cell survival. In pathological settings such as cancer, members of the Bcl-2 gene family are able to synergize with oncogenes and tumor suppressor genes to transform cells. In this review, we describe the process of apoptosis in mammalian cells and define the role and biochemical pathways through which the Bcl-2 gene family induce and/or protect cells from apoptosis. Last, we will discuss the evidence which suggests that alterations in this pathway may play a central role in tumorigenesis by allowing genetically damaged cells normally destined for elimination to persist, predisposing them to additional mutations and driving them to malignancy.

Adult↗
PubMed2003

Post-transcriptional regulation of the Streptomyces coelicolor stress responsive sigma factor, SigH, involves translational control, proteolytic processing, and an anti-sigma factor homolog.

The sigH gene encodes a sigma factor whose transcription is controlled by stress regulatory systems and the developmental program in Streptomyces coelicolor. Here, we describe developmentally regulated post-transcriptional control systems for SigH. sigH is expressed as three primary translation products, SigH-sigma(37), SigH-sigma(51), and SigH-sigma(52). In vitro, SigH-sigma(52) was comparable to SigH-sigma(37) in its ability to associate with RNA polymerase core enzyme and specifically initiate transcription in vitro. While SigH-sigma(51/52) were the primary gene products observed throughout early phases of growth, their abundance decreased during later stages in liquid or solid phase cultures while levels of shorter, C-terminally encoded products increased. These included SigH-sigma(37), a product of the downstream translational initiation site, as well as two proteolytic derivatives of SigH-sigma(51/52) (34kDa and 38kDa). Accumulation of SigH-sigma(37) and processing of SigH-sigma(51/52) into these stable 34kDa and 38kDa derivatives correlated with morphological changes on solid medium and physiological maturation in liquid medium. SigH-sigma(51/52) processing did not occur on medium non-permissive for aerial mycelium formation or in one particular developmental mutant (brgA). The proteolytic activity could be detected in vitro using crude extracts of stationary phase cultures, but was absent from exponential phase cultures. prsH, the gene upstream of sigH having sequence similarity to known anti-sigma factors, was able to bind to, and thus presumably inactivate SigH-sigma(52), SigH-sigma(51), and SigH-sigma(37). We have shown elsewhere that prsH was conditionally required for colonial development. Thus, while at least one transcriptional regulator is known to bring about the accumulation of sigH mRNA at different times and different locations in colonies, the post-transcriptional processes described here regulate the activity of different SigH isoforms and program their temporal accumulation pattern, i.e. the elimination of SigH-sigma(51/52) and accumulation of SigH-sigma(37)-like proteins, as a function of development.

Amino Acid Sequence↗