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At least 19 recordsLinked to original sources
PubMed2026

Transitioning to adult care for patients with IBD: the impact of a structured IBD transition program on service engagement.

BACKGROUND AND AIMS: The British Society of Gastroenterology recommend use of structured transition programs to improve control of chronic gastrointestinal disease in adolescents. We sought to determine the impact of attending a structured transition program on engagement of patients with inflammatory bowel disease (IBD) services and disease outcomes. METHODS: We performed a retrospective multicenter study of patients with IBD prior to and post-transfer to adult services. Patients were grouped into those who attended a structured transition program and those who received standard care, transferred with a referral letter. RESULTS: A total of 282 patients were included: 155 patients in our structured transition program cohort and 127 patients in the standard care cohort. Patients who took part in a structured transition program had significantly better engagement with adult IBD services with significantly lower rates of nonattendance at outpatient clinics 1-year post-transfer (12.3% vs 27.2%, P = .002) and significantly lower rates of disengagement with services (4.2% vs 13.1%, P = .015). There were no significant differences seen in rates of biologic failure, need for steroid/surgery or median fecal calprotectin levels between either group. Attending a structured transition program was the only factor that positively impacted engagement with IBD services in a multivariate analysis (OR 4.08, confidence interval 1.41-11.91, P = .01). CONCLUSION: Structured transition programs in IBD can improve engagement of patients with IBD services with significantly lower rates of disengagement with IBD services seen in our study. Large prospective studies are needed in this field to further investigate this and the impact of these programs on disease outcomes.

Humans↗
PubMed1979

Esophageal scintigraphy to quantitate esophageal transit (quantitation of esophageal transit).

None of the tests employed currently to investigate esophageal transit is quantitative. The purpose of this study was to evaluate normal subjects and patients with a variety of esophageal disorders using a scintigraphic technique to quantitate esophageal transit. After oral administration of a bolus of water labeled with 99mTc-sulfur colloid, isotopic count rates were measured over the esophagus employing a gamma-camera on line to a digital computer. Esophageal transit was expressed as the percent emptying for each of the first 15-sec after the initial swallow and for 15-sec intervals after serial swallows. Sixty-two subjects were studied, including: normal volunteers; patients with motor disorders of the esophagus such as achalasia, diffuse esophageal spasm, and scleroderma; and patients with symptomatic gastroesophageal reflux both with and without esophageal motor dysfunction on manometic testing. Esophageal transit was decreased significantly after single and multiple swallows in patients with motor disorders of the esophagus. In addition, esophageal transit was abnormal in patients with reflux disease accompanied by abnormal motor function. In contrast, esophageal transit was normal after a single swallow, but incomplete after serial swallows in patients with reflux associated with normal esophageal motor function on manometry. We conclude that esophageal scintigraphy may be used to evaluate esophageal transit.

Adult↗
PubMed1979

Mitotic index, influx and mean transit time in the hamster cheek pouch epithelium, a partially synchronized cell system. Presentation of a mathematical model based on a non-stationary probability density function for the transit time in a compartment.

Mitotic activity was followed in the epithelium of the hamster cheek pouch for about 12 hr in two experiments under different conditions of noise and light intensity. A mathematical model based on a non-stationary probability density function for the transit time through mitosis was developed, making an analysis of this partially synchronized cell system possible. The most important result of the two experiments is the indication of a non-stationary mean transit time for cells in mitosis. In the first experiment (70 dB, 103 lux), which produced high mitotic indices (maximum 2.0%), the influx changed from 0. to 0.9%/hr (mean of 7-hourly determinations: 0.4%/hr), and the mean transit time from 1.9 to 5.5 hr. In the second experiment (70 dB, 265 lux), which had a lower level of MI (maximum 1.3%), the influx changed from 0 to 1.8%/hr (mean of 13-hourly determinations: 0.4%/hr), and the mean transit time from 0.3 to 3.3 hr. It was difficult to say precisely whether the variation in influx or in mean transit time was the main factor in the increase and decrease of MI. The data could not be simulated with a stationary mean transit time. It is suggested that changes in MI due to different external circumstances are mainly the result of variation in the mean transit time.

Animals↗
PubMed1978

Transitional steady-state investigations during aerobic-anaerobic transition of glucose utilization by Escherichia coli K-12.

Transitional steady-state investigations during changes in oxygen tension under aerobic and during aerobic-anaerobic transition conditions were carried out with the aim of finding an indicator system which separates the equilibrium from the non-equilibrium state. Of the parameters used i.e. biomass formation, CO2 production, Q02, NADH oxidase, succinate dehydrogenase, phosphofructokinase, glyceraldehyde-3 phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and 2-oxoglutarate dehydrogenase, only the three enzymes requiring NADH or NADP for their function fulfilled the requirements. Biomass production and CO2 formation were useful only during the aerobic-anaerobic transition period. In each case the response was immediate and the indicator systems demonstrated that a new steady state of oxygen was always obtained after 11 h which, at the specific growth rate used, was equivalent to at least two volume replacements of the growth vessel.

Aerobiosis↗
PubMed1977

Observations on the morphology at the transition between the peripheral and the central nervous system in the cat. II. General organization of the transitional region in S1 dorsal rootlets.

The aproximal segment of feline S1 dorsal rootlets were investigated light and electronmicroscopically. A one shaped protrusion of CNS tissue was found to extend distally into each rootlet for a distance of 100-1000 micrometer. That free segment of a rootlet which when cross sectioned revealed both CNS and PNS constituents was denoted the transitional region (TR). The TR was subdivided into an axial CNS compartment and a surrounding PNS compartment. The CNS compartment consisted of a core zone that showed the organisation of a CNS fiber tract, and of an outer astrocytic mantle zone which corresponded to the external glial limiting membrane of the brain and the spinal cord. The outer aspect of the mantle zone constituted the PNS-CNS borderline. The mantle zone was rich in astrocytes and projected a large number of thin processes--the glial fringe--distally into the endoneural space of the PNS compartment. There were large fenestration defects in the basement membrane that demarcated the endoneural space from the glial space. The mantle zone contained many large myelinoid bodies and some encapsulated small dark unclassified cells. Similar cells, some covered by a basement membrane, were at hand in the adjacent endoneural space. The myelinated nerve fibres were equipped with a node of Ranvier at their borderline passage.

Animals↗
PubMed2025

Healthcare transition readiness in an adolescent and young adult urologic population: The ADHERENT study.

INTRODUCTION: There is a paucity of research regarding transition to adult services within pediatric and adolescent urology. Several recent articles have discussed the barriers in transitioning urologic patients from pediatric to adult health care, but empiric data that may drive intervention are lacking. This study proposes to begin to address this gap in literature and to provide information that may lead to improved understanding of how best to support transition in urologic care. OBJECTIVES: 1) to identify modifiable and non-modifiable factors related to transition readiness as measured by Transition Readiness Assessment Questionnaire (TRAQ) scores in a congenital urologic population and 2) to evaluate the relationships between TRAQ scores (a validated questionnaire measuring transition readiness) and scores measuring anxiety levels related to transition (using an adapted, non-validated questionnaire). STUDY DESIGN: This is a cross-sectional study of adolescent and young adult patients with complex congenital urologic diagnoses. Subjects were electronically administered the validated TRAQ and a study-developed ADHERENT survey, which assesses anxiety and worry surrounding transition. Regression models for the outcomes of the TRAQ and ADHERENT scales were developed to assess multivariable associations with variables of clinical importance. RESULTS: The youngest subgroup (14-17 years of age) compared to the oldest subgroup (21-25 years of age) had significantly lower TRAQ scores [regression estimate = 12.3 (95 % CI: 2.9, 21.7), p = 0.010]. Additionally, single participants versus those in a stable relationship had significantly lower TRAQ scores [estimate = 8.7 (95 % CI: 1.9, 15.4), p = 0.012]. The Spearman correlation coefficient between TRAQ and ADHERENT scores was 0.52 (p = <0.001), indicating a positive, moderate relationship between the two measures, suggesting more readiness correlated with less anxiety. DISCUSSION: This study found that age, higher education, and stable relationship status were associated with higher measures of transition readiness. There was a correlation found between more transition readiness and less anxiety surrounding transition. This finding can be used to inform future research and emphasizes the need for multidisciplinary support throughout the transition process. CONCLUSION: Early discussion of transition of care and education around transition readiness are not the only solution to improving transition success. The second phase of ADHERENT seeks to understand the patient experience and to include adolescents and young adults in shaping effective healthcare transition strategies.

Humans↗
PubMed1979

The temperature and pH dependence of conformational transitions of the chromatin subunit.

Hydrodynamic, spectroscopic, and chemical crosslinking studies on monomer chromatin subnits are reported as a function of ionic strength, pH, and temperature. In earlier studies, two salt-dependent conformational transitions were described (Gordon et al., Proceedings of the National Academy of Science, 75, 660, 1978). Transition one occurred between 0.7 and 2.0 mM ionic strength and transition two occurred between 5.0 and 11.0 mM ionic strength. Crosslinking at 11 mM ionic strength with formaldehyde suppressed both transitions. In this communication we report that the second transition was characterized by changes in the circular dichroism spectra in the 260--320 nm region as well as by changes in the hydrodynamic properties. As the ionic strength was increased from 5.0 to 11.0 mM, [theta]282 decreased from 2000 TO 1500 DEG CM2/DMOLE AND [THETA]295 decreased from 0 to -400 deg cm2/dmole. Both transitions occurred in the pH range from pH 6.0 to 9.2. At pH 5.0, the two ionic strength-dependent transitions were no longer observed and the characteristic changes in the circular dichroism spectra were suppressed. The spectra of the monomer subunits at pH 5.0 showed only small changes with ionic strength and resembled the spectra of the subunits at 11 mM ionic strength above pH 6.0. In order to characterize the transitions in thermodynamic terms an ionic strength near the midpoint of each transition was selected. Then, changes in s20,w and D20,w were measured as a function of temperature. These data allow an estimation to be made of the enthalpies and entropies of the transitions.

Chromatin↗
PubMed2026

Online Social Anxiety in the Digital Age: Transitions, Predictors, and Mental Health Associations in Emerging Adulthood.

BACKGROUND: Online social anxiety (OSA), a multidimensional form of social evaluative anxiety in online social contexts, disproportionately affects emerging adults who constitute the largest active group of media users and face heightened psychological sensitivity due to growing pressures and immature sociocognitive regulation during the transition to adulthood. However, its heterogeneity, transitions, and longitudinal associations with mental health outcomes remain underexplored. METHODS: This study utilized data from two waves of a three-wave longitudinal survey, with 849 Chinese participants (Meanage = 21.6 years; 50.4 percent female) assessed at 4-month intervals. Individuals were classified using latent profile analysis and the stability and changes of profiles were assessed via latent transition analysis (LTA). Multinomial logistic regressions were conducted separately at baseline and follow-up to identify correlates of profile membership. Predictors of profile transitions were examined using manual three-step LTA models, and associations between latent transition patterns and follow-up mental health outcomes were examined using BCH-LTA distal outcome analyses controlling for the corresponding baseline symptom level. RESULTS: Four profiles of OSA were identified: low, privacy-sensitive, moderate-high, and high OSA. Extreme profiles (low/high OSA) showed high stability (80.4 percent and 79.1 percent), while privacy-sensitive OSA exhibited the lowest stability (55.1 percent). Profile memberships were influenced by social-cognitive biases and digital interaction, particularly fear of negative evaluation and online interpersonal trust, whereas profile transitions were mainly associated with anxiety. Transitions toward less severe OSA profiles were generally associated with better subsequent mental health, whereas transitions toward more severe profiles corresponded to poorer outcomes, particularly for offline social anxiety. CONCLUSION: OSA was heterogeneous in its manifestation, severity and transitions. Personalized and early interventions targeting profile-specific vulnerabilities are critical to prevent the worsening of OSA and mitigate its psychological burden.

Humans↗
PubMed1979

Assessment of carotid artery stenosis using pulse wave transit time.

A prospective study has been undertaken on 24 patients to establish the relationship between the degree of internal carotid artery stenosis, as estimated by arteriography, and the pulse wave transit time in the carotid artery. The technique involves the simultaneous use of two continuous wave Doppler velocimeters, one on the carotid and one on the supraorbital artery, to measure the flow waves and hence deduce the pulse wave transit times. The measured transit times varied from 17 to 124 ms with a beat-to-beat variation of 11 per cent. The absolute transit time in any segment correlated moderately well with the estimated degree of stenosis (r = 0.68, P less than 0.001). However, normalization of the transit times, to correct for the effects of blood pressure and age, produced on improved correlation between the variables (r = 0.8, P less than 0.001). Normalization was achieved by dividing the common carotid to supraorbital transit time by the shortest transit time found between the common carotid and either the superficial temporal or brachial arteries. Significant differences in the normalized transit times were found between arteries that were diametrically stenosed by more than 50 per cent, by between 21 and 50 per cent and by 20 per cent or below. It is concluded that pulse wave transit time measurement can provide a simple and reproducible non-invasive technique for the diagnosis of varying degrees of carotid artery stenosis.

Adult↗
PubMed1979

Helix-coil transition of the self-complementary dG-dG-dA-dA-dT-dT-dC-dC duplex.

The helix-coil transition of the octanucleotide self-complementary duplex dG-dG-dA-dA-dT-dT-dC-dC has been monitored at the Watson-Crick protons, the base and sugar nonexchangeable protons and the backbone phosphates by high-resolution nuclear magnetic resonance (NMR) spectroscopy. The melting transition of the octanucleotide monitored by ultraviolet absorbance spectroscopy is characterized by the thermodynamic parameters delta H degree = -216.7 kJ/mol and delta S degree (25 degrees C) = -0.632 KJ mol-1 K-1 in 0.1 M NaCl, 10 mM phosphate solution. Correlation of the transition midpoint values monitored by the ultraviolet absorbance studies at strand concentrations below 0.2 mM and by NMR studies at 5.3 mM suggest that both methods are monitoring the octanucleotide duplex-to-strand transition. The NMR spectra of the Watson-Crick ring NH protons of the octanucleotide duplex have been followed as a function of temperature. The resonance from the terminal dG.dC base pairs broadens out at room temperature while the resonances from the other base pairs broaden simultaneously with the onset of the melting transition. The nonexchangeable base and sugar H-1' protons are resolved in the duplex and strand states and shift as average peaks through the melting transition. The experimental shifts on duplex formation have been compared with calculated values based on ring-current and atomic diamagnetic anisotropy contributions for a B-DNA base-pair-overlap geometry in solution. Several nonexchangeable proton resonances broaden in the fast-exchange region during the duplex-to-strand transition and the excess widths yield a duplex dissociation rate constant for the octanucleotide of 1.9 x 10(3) s-1 at 32 degrees C (fraction of duplex = 0.86) in 0.1 M NaCl, 10 mM phosphate buffer. The 31P resonances of the seven internucleotide phosphates are distributed over 0.6 ppm in the duplex state, shift downfield during the duplex-to-strand transition and undergo additional downfield shifts during the stacked-to-unstacked strand transition with increasing temperature.

Magnetic Resonance Spectroscopy↗
PubMed2026

Predictors of transition readiness in adolescents with neurogenic lower urinary tract dysfunction.

PURPOSE: Adolescents with Neurogenic Lower Urinary Tract Dysfunction (NLUTD) face significant challenges in their quality of life and readiness to transition to adult healthcare services. This study examines the impact of various demographic and clinical factors on transition readiness. METHODS: We performed a retrospective review of prospectively collected data from 75 adolescents with NLUTD managed at a specialized tertiary referral pediatric facility. We employed multivariate linear regression analysis to explore the relationship between transition readiness scores collected from the Good2Go questionnaire, including the total transition readiness score and its sub-domains (self-advocacy, knowledge, self-care, and social support), and predictors such as age, sex, reconstructive surgery status, and clean intermittent catheter (CIC) usage. RESULTS: The mean age of participants was 16.74 years (SD 2.44). Reconstructive surgery had been performed in 32 % of patients, and 77.3 % were on CIC. Multivariate regression analysis indicated that age significantly predicted transition readiness across several domains. Each additional year of age was associated with a 4.40-point increase in the total transition readiness score, a 3.66-point increase in knowledge, a 4.26-point increase in self-advocacy and a 5.41-point increase in self-care. Conversely, CIC significantly negatively impacted the social support domain, with scores decreasing by 9.69 points. Reconstructive surgery was significantly associated with lower self-care scores, with an average decrease of 12.12 points among those who had undergone surgery. CONCLUSION: Age significantly improves transition readiness in adolescents with NLUTD, reflecting cognitive and developmental growth. However, the negative effects of CIC on social support and reconstructive surgery on self-care underscore the need for personalized interventions to optimize health outcomes during the transition to adult care.

Humans↗
PubMed1977

Cooperativity of the phase transition in single- and multibilayer lipid vesicles.

The effect of membrane morphology on the cooperativity of the ordered-fluid, lipid phase transition has been investigated by comparing the transition widths in extended, multibilayer dispersons of dimyristoyl phosphatidyl-choline, and also of dipalmitoyl phosphatidylcholine, with those in the small, single-bilayer vesicles obtained by sonication. The electron spin resonance spectra of three different spin-labelled probes, 2,2,6,6-tetramethylpiperdine-N-oxyl, phosphatidylcholine and stearic acid, and also 90 degrees light scattering and optical turbidity measurements were used as indicators of the phase transition. In all cases the transition was broader in the single-bilayer vesicles than in the multibilayer dispersions, corresponding to a decreased cooperativity on going to the small vesicles. Comparison of the light scattering properties of centrifuged and uncentrifuged, sonicated vesicles suggests that these are particularly sensitive to the presence of intermediate-size particles, and thus the spin label measurements are likely to give a more reliable measure of the degree of cooperativity of the small, single-bilayer vesicles. Application of the Zimm and Bragg theory ((1959) J. Chem. Phys. 31, 526-535) of cooperative transitions to the two-dimensional bilayer system shows that the size of the cooperative unit, 1/square root sigma, is a measure of the mean number of molecules per perimeter molecule, in a given region of ordered or fluid lipid at the centre of the transition. From this result it is found that it is the vesicle size which limits the cooperativity of the transition in the small, single-bilayer vesicles. The implications for the effect of membrane structure and morphology on the cooperativity of phase transitions in biological membranes, and for the possibility of achieving lateral communication in the plane of the membrane, are discussed.

Chemical Phenomena↗
PubMed1975

Phase transitions and phase separations in phospholipid membranes induced by changes in temperature, pH, and concentration of bivalent cations.

Differential scanning calorimetry (DSC) and fluorescence polarization of embedded probe molecules were used to detect phase behavior of various phospholipids. The techniques were directly compared for detecting the transition of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidic acid (DPPA) dispersed in aqueous salt solutions. Excellent agreement occurred in the case of phosphatidylcholine; however, in the case of phosphatidic acid, at pH 6.5, transitions detected by fluorescence polarization using the disc-like perylene molecule occurred about 10 degrees lower than those detected by DSC. Discrepancy between fluorescence and DSC methods is eliminated by using a rod-like molecule, diphenylhexatriene (DPH). Both techniques show that doubly ionizing the phosphate group reduces the Tc by about 9 degrees. Direct pH titration of fluidity can be accomplished and this effect is most dramatic when membranes are in their transition temperature range (ca. 50 degrees). Phosphatidic acid transitions occur at higher temperatures, and have appreciably lower transition enthalpies and entropies than phosphatidylcholine. These effect could not be explained simply on the basis of double layer electrostatics and several other factors were discussed in an attempt to rationalize the results. Addition of monovalent cations (0.01-0.5 M) is shown to increase the Tc of dipalmitoylphosphatidylglycerol by less than 3 degrees. However, addition of (1 x 10-3 M) Ca2+ abolishes the phase transition of both phosphatidyglycerol and phosphatidylserine in the range 0-70 degrees. Preliminary X-ray evidence indicates the phosphatidylserine-Ca2+ bilayers are in a crystalline state at 24 degrees. In contrast, 5 x 10-3 M Mg2+ only broadens the transition and increases the Tc indicating a considerable difference between the effects of Ca2+ and Mg2+. Neutralization of PS increases the Tc from 6 degrees (at pH 7.4) to 20-26 degrees (at pH 2.5-3.0) but does not abolish the transition, suggesting the Ca2+ effect involves more than charge neutralization. Addition of Ca2+ to mixed phosphatidylserine-phosphatidylcholine dispersions, induces a phase separation of the dipalmitoyl- (and also distearoyl-) phosphatidylcholine as seen by the appearance of a new endothermic peak at 41 degrees (58 degrees). Similarly, in mixed (dipalmitoyl) phosphatidic acid-phosphatidylcholine (2:1) dispersions, Ca2+ again can separate the phosphatidylcholine component.

Binding Sites↗
PubMed1979

Transit times through the cycle phases of jejunal crypt cells of the mouse. Analysis in terms of the mean values and the variances.

Mean transit times as well as variances of the transit times through the individual phases of the cell cycle have been determined for the crypt epithelial cells of the jejunum of the mouse. To achieve this the fraction of labelled mitoses (FLM) technique has been modified by double labelling with [3H] and [14C]thymidine. Mice were given a first injection of [3H]thymidine, and 2 hr later a second injection of [14C]thymidine. This produces a narrow subpopulation of purely 3H-labelled cells at the beginning of G2-phase and a corresponding subpopulation of purely 14C-labelled cells at the beginning of the S-phase. When these two subpopulations progress through the cell cycle, one obtains FLM waves of purely 3H- and purely 14C-labelled mitoses. These waves have considerably better resolution than the conventional FLM-curves. From the temporal positions of the observed maxima the mean transit times of the cells through the individual phases of the cycle can be determined. Moreover one obtains from the width of the individual waves the variances of the transit times through the individual phases. It has been found, that the variances of the transit times through successive phases are additive. This indicates that the transit times of cells through successive phases are independently distributed. This statistical independence is an implicit assumption in most of the models applied to the analysis of FLM curves, however there had previously been no experimental support of this assumption. A further result is, that the variance of the transit time through any phase of the cycle is proportional to the mean transit time. This implies that the progress of the crypt epithelial cells is subject to an equal degree of randomness in the various phases of the cycle.

Analysis of Variance↗