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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↗
PubMed1998

Assessing transitional phenomena with the transitional object memory probe.

Winnicott's concept of transitional relatedness has captured the interest of psychoanalysts because it provides an understanding of the dialectical process occurring between inner and outer reality, and by extension, between analyst and analysand. Clinical observations related to transitional phenomena have led the authors to develop a projective early memory probe that assesses transitional phenomena. The transitional object early memory probe was tested both for its empirical validity and for its clinical utility in psychodynamic psychotherapy. Construct validity was assessed by comparing memory scores to the Rorschach Transitional Object Scale, as well as to therapist ratings of patient behaviors. Results demonstrated moderate correlations between early memory scores and Rorschach scale scores. Equally important was the finding that early memory scores were significantly correlated with therapist ratings of key behavioral patterns in therapy. A case vignette highlights the clinical application of the transitional object probe in assessing the capacity for transitional relatedness. In this case, the data gleaned from the patient's memories provided the therapist with a sharper focus on their role in the patient's growing capacity for more vital and creative contact with reality.

Adult↗
PubMed1996

Role of segmental colonic transit time studies to select patients with slow transit constipation for partial left-sided or subtotal colectomy.

This prospective study investigated the value of segmental colonic transit time studies in the surgical treatment of slow transit constipation. Overall, 346 patients with chronic constipation were analysed; slow transit constipation was diagnosed in 86 (25 per cent). Based on the results of segmental colonic transit time studies, 18 patients underwent partial left-sided colectomy and 24 subtotal colectomy. Recurrent constipation was seen in three of 18 patients and seven of 24 respectively. Severe abdominal discomfort was noted in six of 18 and 15 of 24 respectively. Disabling diarrhoea and faecal incontinence developed in two of 14 and five of 20 patients with an anastomosis respectively. Although these results indicate that segmental colonic transit time studies are useful in selecting patients with slow transit constipation for partial left-sided or subtotal colectomy, both procedures should be performed with prudence.

Adolescent↗
PubMed2005

Radionuclear transit to assess sites of delay in large bowel transit in children with chronic idiopathic constipation.

PURPOSE: Chronic idiopathic constipation (CIC) with soiling in children may result from slow colonic transit (SCT) or anorectal dysfunction and/or psychological problems known as functional fecal retention (FFR). Evidence is accumulating that SCT and FFR need different treatments, but they are poorly distinguished by solid marker studies. The authors used radionuclear transit scintigraphy to categorize children with CIC as having either FFR or SCT. METHODS: Children (N = 101) with CIC (and soiling) who were referred for further investigation after failure of standard treatments (diet, laxatives) received radiolabeled colloid orally, and scintillation images were collected at 0 to 2, 6, 24, 30 and 48 hours (total radiation dosage = 2 standard x-rays). Radioactivity in 6 regions (precolonic, ascending, transverse, descending, rectosigmoid, and evacuated feces) was measured, and the median position (geometric center) of radioactivity at each time was determined. RESULTS: In children, meals normally reach the cecum at 6 hours and are evacuated in 30 to 58 hours. Fifty patients had retention of radioactivity in the proximal colon at 48 hours, indicating SCT. Analysis of the images and the geometric center showed that passage through the ascending colon and transverse colon was delayed in SCT. In 24 patients, radioactivity was passed by 30 hours, indicating normal transit or possible FFR. Twenty-two patients had retention in the rectum, indicating definite FFR. Five studies were borderline. CONCLUSIONS: Radionuclear transit scintigraphy is useful for categorizing patients with CIC as having either FFR or SCT, allowing for different treatments. Radionuclear transit scintigraphy provides more detail and greater sensitivity than solid marker studies in diagnosing CIC. Radionuclear transit scintigraphy showed that half of our patients had SCT.

Cecum↗
PubMed2002

Abnormalities of GI transit in bloated irritable bowel syndrome: effect of bran on transit and symptoms.

OBJECTIVES: Bloating is an important but poorly understood symptom in irritable bowel syndrome (IBS) that is often aggravated by bran. The aim of our study was to determine whether IBS patients with bloating responded to bran differently from healthy controls. METHODS: A total of 12 patients with IBS (according to Rome I criteria), all with moderate to severe bloating, and 12 healthy controls participated in a two way, double blind, randomized, cross-over trial of bran versus placebo (crushed biscuits) 15 g b.i.d. An average daily pain index and bloating score were derived from daily symptom diaries. On day 14, gastric emptying, small bowel transit, percent remaining in ascending colon, and geometric center of a meal marker at 24 h were calculated from scintigraphic images obtained after ingesting a Tc99m-labeled rice pudding meal with 15 g of either placebo or coarse bran. RESULTS: Results are given as median (range). Bran significantly increased the pain index and bloating (p < 0.02) in IBS patients but not controls. The most striking finding was that the small bowel transit time of the meal without bran was markedly faster in IBS patients than in controls, being 203 min (range 109-313) versus 367 min (219-543), p < 0.001. Although in controls bran accelerated small bowel transit time to 262 min (180-380), p = 0.03, and significantly reduced % remaining in the ascending colon from 22% (0-46) to 3% (0-25), p = 0.03, this was not seen in the IBS patients. Bran accelerated whole gut transit as assessed by geometric center at 24 h in both IBS patients and controls. CONCLUSIONS: Bran accelerates small bowel transit and ascending colon clearance without causing symptoms in controls. Small bowel transit is rapid in IBS patients with bloating and, unlike in healthy control subjects, cannot be further accelerated by bran, which nevertheless aggravates symptoms of pain and bloating. We speculate that bran-induced bloating may originate in the colon rather than the small bowel.

Adult↗
PubMed1999

A modified radiographic method for estimating segmental colonic transit time in subjects with rapid gut transit.

In this study on Indian subjects, the single X-ray method was assessed for its reliability in measuring the transit of particulate matter through the colon, and if inaccurate a suitable and simple alternative was to be devised. Radio-opaque markers were serially followed in 20 normal male volunteers. This was done by three 12 hourly radiographs and by stool collection to determine the transit time through the colon and its segments. It was compared with similar parameters calculated from the same data using one radiograph and three combinations of two radiographs each. The mean +/- SD colonic transit time determined by using three X-rays was 18.0 +/- 6.6 h which agreed well with the mean mouth-to-anus transit time of 24.2 +/- 6.8 h (mean +/- SDdiff = -6.2 +/- 2.9). When two of the three X-rays were used in various combinations, the best results were obtained with the method including radiographs at 12 and 36 h. Parameters calculated from a single radiograph done 36 h after the ingestion of makers showed lesser agreement with the results of the three radiograph method. Therefore in subjects with rapid gut transit, the simplified method for estimating the colonic and segmental transit times using a single X-ray is inaccurate. Using two radiographs enhances the accuracy.

Colon↗
PubMed1992

Transition time control analysis of a glycolytic system under different glucose concentrations. Control of transition time versus control of flux.

Control and Response Coefficients of transition time have been determined in a rat liver glycolytic system under different glucose concentrations. Results have been compared with the Flux Control and Flux Response Coefficients measured in the same conditions, showing that transition time and flux are different responses of the system, subject to different regulation and control. Control Coefficients of flux and transition time show a very different profile in each condition of glucose concentration assayed. Ratio of Flux Control coefficients of glucokinase over phosphofructokinase at 5 and 20 mM glucose concentration changes from 3.2 to 0.5, while the same ratio in the case of Transition Time Control Coefficients moves from 0.6 to 0.93. Moreover, the absolute values of Transition Time Control Coefficients in glycolytic conditions are one order of magnitude bigger than in gluconeogenic conditions. Values of Response Coefficients also show that the transition time has a bigger sensitivity to changes in glucose concentration than the flux in all conditions assayed, but particularly in glycolytic ones.

Animals↗
PubMed1987

Interaction of urinary Tamm-Horsfall protein with transitional cells and transitional epithelium.

Uropathogenic E. coli that express mannose sensitive adhesins adhere to agglutinated urinary Tamm-Horsfall protein (THP) and to exfoliated transitional epithelial cells coated with THP. Whether THP interacts with the transitional epithelium in vivo and facilitates adhesin mediated attachment of E. coli is not known. Using immunohistochemical techniques we could not identify THP associated with formalin-fixed, paraffin-embedded transitional epithelium from a variety of sites within the urinary tract. However, varying levels of THP associated with the washed exfoliated transitional cells from 10 different subjects were detected by indirect radioimmunoassay methodologies. After in vitro incubation in human urine the mean interaction of THP with the exfoliated transitional cells increased significantly but closely paralleled the mean interaction of THP with exfoliated vaginal and buccal epithelial cells after identical incubation. We conclude that the interaction of THP with transitional cells in vivo is nonspecific and occurs after detachment from the mucosa. THP may act as a natural host defense against E. coli bacteriuria by inhibition of adhesion mediated bacterial adherence to the urothelium.

Adhesins, Escherichia coli↗
PubMed1997

Renal vascular transit time and tubular transit time dispersion for 99Tcm-MAG3.

Renal transit time usually refers to tubular transit time, as introduced by Taplin, but other measures of renal transit have been proposed. Here we examine the vascular transit time (VTT, following Rutland) and the standard deviation of tubular transit time (SDTT, following Britton) in a group of 30 patients having baseline and ACE-inhibitor 99Tcm-MAG3 renography prior to arteriography. A same-day, low-dose/high-dose protocol was used for renography; only the post-captopril dose was high enough to measure VTT. Pre-captopril, the Spearman rank correlation coefficient for SDTT was rho = 0.52 (n = 53 kidneys; P < 0.0002); post-captopril, rho = 0.54 (n = 49 kidneys; P < 0.0002). For VTT, the post-captopril value was rho = 0.24 (n = 30 kidneys; N.S.). For comparison, the same statistics were calculated for Taplin's original measure of transit time: the time from injection to maximum count rate (peak time). Pre-captopril, for peak time, rho was 0.47 (n = 53 kidneys; P < 0.001); post-captopril, rho was 0.39 (n = 50 kidneys, P < 0.01). These findings confirm the diagnostic value of SDTT but not of VTT. SDTT correlated better than peak time with the arteriographic findings.

Adult↗
PubMed2001

Nature of the liquid crystalline phase transitions in the cesium pentadecafluorooctanoate (CsPFO)-water system: the nematic-to-isotropic transition.

Deuterium NMR spectroscopy of 2H2O has been used to monitor the magnetic-field-induced order on approaching a transition to a nematic phase in isotropic solutions of disklike micelles of cesium pentadecafluorooctanoate. Highly accurate data on the phase boundaries and spinodals have been obtained for solutions with volume fraction concentration straight phi between 0.078 and 0.201. The quantity TIN-T*, where T* is the spinodal limit of the isotropic phase and TIN is the temperature at which the nematic phase first appears on cooling, decreases linearly with decreasing concentration, extrapolating to zero only at zero concentration. Thus, there is no evidence to support the presence of a Landau point along the transition line as has previously been conjectured. The values for (TIN-T*)/TIN are in the range 10(-5)-10(-4), up to two orders of magnitude smaller than corresponding values reported for calamitic thermotropic nematics. The transition gap (phiNI-phiIN)/phiIN approximately 0.33% for phi<0.20 is also very small, although finite as required for a first-order phase transition. These data, when combined with previously measured properties, present an intriguing picture of the isotropic-to-nematic phase transition in a paradigmatic system of self-assembled diskotic particles. However, it is not completely clear, within the context of current theoretical understanding, whether the behavior of this system is explicable by hard-particle models, or if the self-assembly plays a crucial role in weakening the phase transition.

Journal Article↗
PubMed2002

Two experimental tests of a fluctuation-induced first-order phase transition: intensity fluctuation microscopy at the nematic-smectic-A transition.

We have developed a new, extremely sensitive real-space technique (intensity fluctuation microscopy) to probe the order of the nematic-smectic-A (NA) transition. Using this technique, we show that the NA transition in 4'-n-octyl-4-cyanobiphenyl (8CB) is clearly first order, contrary to calorimetric studies but in agreement with conclusions drawn from front-velocity measurements. We characterize the strength of the discontinuity at the first-order transition by the dimensionless quantity t(0)=(T(NA)-T*)/T(*). By precisely measuring t(0), we have made the first detailed tests of predictions based on the Halperin-Lubensky-Ma (HLM) theory of fluctuation-induced, first-order phase transitions. First, we explore the effect of an external magnetic field on the NA transition. Although modest fields (of order 10 T) are predicted to drive the weakly first-order transition in pure 8CB second order, we observe no such effect; we establish instead that the lower bound on this critical field is approximately 30 T. Likewise, we observe no effect in mixtures of 8CB with its longer chemical homolog 4'-n-decyl-4-cyanobiphenyl (10CB). Second, we examine the dependence of t(0) as a function of 8CB-10CB mixture concentration and find that the data in mixtures with small nematic temperature range are well-fit by the parameters derived by Anisimov et al. based on calorimetric measurements. As we increase the nematic range (by using concentrations closer to pure 8CB), the measured t(0) deviates more and more from the HLM predictions. Smectic fluctuations, which are neglected in the HLM calculation, are an obvious candidate to explain such a discrepancy, but one's naive expectation is that they would reduce t(0) below the HLM levels, whereas the observed values are too large. However, a recent renormalization-group calculation concludes that smectic fluctuations, surprisingly, should indeed increase t(0), explaining the observations presented here.

Journal Article↗
PubMed2004

State transitions in Chlamydomonas reinhardtii. The role of the Mehler reaction in state 2-to-state 1 transition.

The light intensity-dependent transition to state 1 of dark-adapted anaerobic state 2 Chlamydomonas reinhardtii cells is stimulated by oxygen and by other electron acceptors for photosystem I, such as oxaloacetate and methylviologen. This suggests that the transition to state 1 requires the oxidation of the intersystem chain by photosystem I photochemistry. On the other hand, the mere oxidation in the dark of the chain-by addition of O2-leads only to a slow and incomplete transition. The light-driven stimulation by O2 of the state 1 transition is saturated at an O2 concentration of 15 to 20 microm, definitely higher than that of respiration. We suggest that this may represent the affinity for oxygen of the Mehler reaction, a conclusion that is confirmed by the observations that mitochondrial respiration is apparently not involved in modulating state 2-to-state 1 transition. The catalysis of the state 2-to-state 1 transition upon illumination of anaerobically adapted algae might represent, therefore, a relevant physiological role of this process in C. reinhardtii.

Algal Proteins↗
PubMed2001

Nomenclature of magnetic, incommensurate, composition-changed morphotropic, polytype, transient-structural and quasicrystalline phases undergoing phase transitions. II. Report of an IUCr Working Group on Phase Transition Nomenclature.

A general nomenclature applicable to the phases that form in any sequence of transitions in the solid state has been recommended by an IUCr Working Group [Acta Cryst. (1998). A54, 1028-1033]. The six-field notation of the first Report, hereafter I, was applied to the case of structural phase transitions, i.e. to transformations resulting from temperature and/or pressure changes between two crystalline (strictly periodic) phases involving modifications to the atomic arrangement. Extensive examples that illustrate the recommendations were provided. This second Report considers, within the framework of a similar six-field notation, the more complex nomenclature of transitions involving magnetic phases, incommensurate phases and transitions that occur as a function of composition change. Extension of the nomenclature to the case of phases with less clearly established relevance to standard schemes of transition in equilibrium systems, namely polytype phases, radiation-induced and other transient phases, quasicrystalline phases and their transitions is recommended more tentatively. A uniform notation for the translational periodicity, propagation vector or wavevector for magnetic and/or incommensurate substances is specified. The notation adopted for incommensurate phases, relying partly on the existence of an average structure, is also consistent with that for commensurate phases in a sequence. The sixth field of the nomenclature is used to emphasize the special features of polytypes and transient phases. As in I, illustrative examples are provided for each category of phase sequence.

Journal Article↗
PubMed1999

Measuring transitions through stages of exercise: application of latent transition analysis.

In this longitudinal study of 504 nursing staff members from seven Dutch nursing homes, which transitions in exercise behaviour had occurred over a 12-mo. period were investigated. For this purpose, latent transition analyses were employed. Latent transition analysis is an extension of Markov chain modelling and of Latent class analysis and has been especially developed to study dynamic latent variables. The data supported the notion that natural change in exercise occurs through various stages and that these are sequential in nature. Latent transition analysis was an effective method for the comparison of various models describing possible transitions over time and for estimation of the likelihood of the occurrence of such transitions.

Adult↗
PubMed2005

Calculating colon transit time with radionuclide-filled capsules in constipated patients: a new method for colon transit study.

BACKGROUND: Colon motility disorders require reliable methods for calculating segmental colonic transit time. This study evaluated bowel transit time by means of a safe, easy, cheap, non-digestive, and non-disintegrating radionuclide-filled capsule that provided accurate and clear images. METHODS: Radionuclide-filled mini-containers (MCs) were prepared from infusion sets by an apparatus used for sealing blood bags or plasmapheresis sets. In vitro stability studies were performed by immersing 5% methylene blue dye-filled MCs in buffers of variable pH and enzymes simulating the conditions in the stomach and the small bowel. Colon transit scintigraphy was performed with MCs filled with iodine 131 (n = 5) and thallium 201 (n = 8) that were placed in a commercially available capsule. RESULTS: By in vitro acid, base, and intestinal enzyme resistance tests, no methylene blue leakage was determined visually and by spectrophotometric analysis. Accurate and clear images were obtained for colon transit study in constipated patients. After excretion of MCs in the feces, abdominal, myocardial, thyroid, and urinary bladder region counts were found to show the same activity as the background. Radionuclide leakage from MCs was not determined in vivo by gamma camera. CONCLUSIONS: This is a suitable, safe, easy, and cheap method to provide accurate and clear images for colon transit study in constipated patients.

Adult↗
PubMed1988

Transitional cell carcinoma of the prostate following intravesical therapy for transitional cell carcinoma of the bladder.

From 1983 to 1986, 63 male patients received various regimens of intravesical therapy for superficial transitional cell carcinoma of the bladder. Of these 63 patients 10 were subsequently diagnosed as having transitional cell carcinoma of the prostate. Five of the 10 patients had no tumor remaining in the bladder at diagnosis of transitional cell carcinoma of the prostate. In 3 patients tumor in the prostate was more invasive than tumor in the bladder. In 2 patients tumor involvement was greater in the bladder than in the prostate. Patients undergoing treatment with intravesical therapy for transitional cell carcinoma of the bladder, especially those receiving multiple courses for prolonged periods, should be monitored closely for the development of transitional cell carcinoma of the prostate.

Administration, Intravesical↗
PubMed2004

Central CRF, urocortins and stress increase colonic transit via CRF1 receptors while activation of CRF2 receptors delays gastric transit in mice.

Recently characterized selective agonists and developed antagonists for the corticotropin releasing factor (CRF) receptors are new tools to investigate stress-related functional changes. The influence of mammalian CRF and related peptides injected intracerebroventricularly (i.c.v.) on gastric and colonic motility, and the CRF receptor subtypes involved and their role in colonic response to stress were studied in conscious mice. The CRF(1)/CRF(2) agonists rat urocortin 1 (rUcn 1) and rat/human CRF (r/h CRF), the preferential CRF(1) agonist ovine CRF (oCRF), and the CRF(2) agonist mouse (m) Ucn 2, injected i.c.v. inhibited gastric emptying and stimulated distal colonic motor function (bead transit and defecation) while oCRF(9-33)OH (devoid of CRF receptor affinity) showed neither effects. mUcn 2 injected peripherally had no colonic effect. The selective CRF(2) antagonist astressin(2)-B (i.c.v.), at a 20 : 1 antagonist: agonist ratio, blocked i.c.v. r/hCRF and rUcn 1 induced inhibition of gastric transit and reduced that of mUcn 2, while the CRF(1) antagonist NBI-35965 had no effect. By contrast, the colonic motor stimulation induced by i.c.v. r/hCRF and rUcn 1 and 1h restraint stress were antagonized only by NBI-35965 while stimulation induced by mUcn 2 was equally blocked by both antagonists. None of the CRF antagonists injected i.c.v. alone influenced gut transit. These data establish in mice that brain CRF(1) receptors mediate the stimulation of colonic transit induced by central CRF, urocortins (1 and 2) and restraint stress, while CRF(2) receptors mediate the inhibitory actions of these peptides on gastric transit.

Animals↗