Marrow Fat Quality Differences by Sex in Healthy Adults.

Several studies have demonstrated the relationship between bone marrow adiposity (BMAT) and bone mass. 1H magnetic resonance spectroscopy is a noninvasive technique able to assess both BMAT quantity and quality. The aim of our study was to perform quantitative and qualitative analyses of BMAT and to investigate its association with bone mineral density (BMD) in healthy nonobese volunteers. Fifty-one healthy volunteers, 21 men and 30 women, underwent 1.5 T 1H magnetic resonance spectroscopy of the lumbar spine. BMD was determined by dual-energy X-ray absorptiometry of the lumbar spine. Correlation analysis was performed to evaluate association among lipids fractions, BMD, and age. The female and male volunteers had similar body mass index and BMD (p > 0.05). Our data demonstrated an inverse correlation of BMD and BMAT with age, with a stronger correlation of saturated lipids (r = 0.701; p < 0.0001) compared with unsaturated lipids (UL) (r = 0.278; p = 0.004). Importantly, female subjects had the highest amount of UL (confidence interval: 0.685%-1.722%; p < 0.001). Our study reports that men and women with similar BMD and body mass index have striking differences in bone marrow lipids composition, namely women have higher UL than men. In addition, we believe that our study brings new insights to the complex network involving BMAT and other factors that influence bone integrity.

Evaluation of oesophageal transit velocity using the improved Demons technique.

PURPOSE: This paper presents a novel method to compute oesophageal transit velocity in a direct and automatized manner by the registration of scintigraphy images. METHODS: A total of 36 images from nine healthy volunteers were processed. Four dynamic image series per volunteer were acquired after a minimum 8 h fast. Each acquisition was made following the ingestion of 5 ml saline labelled with about 26 MBq (700 µCi) technetium-99m phytate in a single swallow. Between the acquisitions, another two swallows of 5 ml saline were performed to clear the oesophagus. The composite acquired files were made of 240 frames of anterior and posterior views. Each frame is the accumulate count for 250 ms.At the end of acquisitions, the images were corrected for radioactive decay, the geometric mean was computed between the anterior and posterior views and the registration of a set of subsequent images was performed. Utilizing the improved Demons technique, we obtained from the deformation field the regional resultant velocity, which is directly related to the oesophagus transit velocity. RESULTS: The mean regional resulting velocities decreases progressively from the proximal to the distal oesophageal portions and, at the proximal portion, is virtually identical to the primary peristaltic pump typical velocity. Comparison between this parameter and 'time-activity' curves reveals consistency in velocities obtained using both methods, for the proximal portion. CONCLUSION: Application of the improved Demons technique, as an easy and automated method to evaluate velocities of oesophageal bolus transit, is feasible and seems to yield consistent data, particularly for the proximal oesophagus.

A novel dynamic scintigraphic technique for assessing duodenal contractions during gastric emptying in humans: a feasibility study.

Duodenal contractions are thought to play a role in the control of gastric emptying. Although noninvasive techniques, such as ultrasonography and MRI, have been proposed for studying duodenal contractile activity in humans, there are no reports on the use of scintigraphy for this purpose. This work aimed to describe a novel scintigraphic technique for assessing duodenal contractility during gastric emptying in humans, and to present preliminary data on the frequency and amplitude of contractions detected in three different duodenal segments. Fasted young healthy volunteers (N=12) were given either a liquid or a solid test meal of similar calorie content (400 kcal) labeled with 99mTc-phytate. Static images were collected to determine gastric emptying. Dynamic images of the anterior aspect of the abdomen (1 frame/s) were also acquired periodically in a standard position for 256 s at 15-30 min intervals. 'Activity versus time' curves were generated for regions of interest corresponding to the proximal, middle, and distal duodenal segments. Curves were digitally filtered and processed to estimate both dominant frequency (fast Fourier transform) and amplitude (mean ejection fraction) of postprandial duodenal contractions. There were no significant differences regarding dominant frequency among proximal, middle, and distal duodenal regions of interest. In addition, there were no significant differences between the liquid and the solid meal in terms of either frequency or amplitude of duodenal contractions. Characterization of duodenal contractions in humans using scintigraphy is feasible and yields consistent data for both the frequency and the amplitude of postprandial contractions, which seems to be rather independent of meal consistency.

Determinants of accelerated small intestinal transit in alcohol-related chronic pancreatitis.

Patients with chronic pancreatitis may have abnormal gastrointestinal transit, but the factors underlying these abnormalities are poorly understood. Gastrointestinal transit was assessed, in 40 male outpatients with alcohol-related chronic pancreatitis and 18 controls, by scintigraphy after a liquid meal labeled with (99m)technetium-phytate. Blood and urinary glucose, fecal fat excretion, nutritional status, and cardiovascular autonomic function were determined in all patients. The influence of diabetes mellitus, malabsorption, malnutrition, and autonomic neuropathy on abnormal gastrointestinal transit was assessed by univariate analysis and Bayesian multiple regression analysis. Accelerated gastrointestinal transit was found in 11 patients who showed abnormally rapid arrival of the meal marker to the cecum. Univariate and Bayesian analysis showed that diabetes mellitus and autonomic neuropathy had significant influences on rapid transit, which was not associated with either malabsorption or malnutrition. In conclusion, rapid gastrointestinal transit in patients with alcohol-related chronic pancreatitis is related to diabetes mellitus and autonomic neuropathy.

Gastrointestinal transit, appetite, and energy balance in gastrectomized patients.

BACKGROUND: Alterations in gastrointestinal tract physiology after gastrectomy may affect appetite and energy balance. OBJECTIVE: The objective of this study was to examine energy balance, appetite, and gastrointestinal transit in subjects with gastrectomy. DESIGN: Seven subjects with total gastrectomy (TG) and 14 subjects with partial gastrectomy (PG), who were free from signs of recurrent disease, and 10 healthy control subjects were studied. Resting energy expenditure (REE) was measured by indirect calorimetry and compared with REE predicted by the Harris-Benedict equation (mREE/pREE%). Gastrointestinal transit was measured by scintigraphy. Habitual food intake was assessed, and appetite was measured during scintigraphy after ingestion of a test meal (361 kcal). RESULTS: Body mass index was not different among the groups. mREE/pREE% was higher in patients with PG (P < 0.01) than in control subjects. The TG group showed higher energy intake (P < 0.05) than the PG group and control subjects. Gastric emptying was faster in the PG group than in control subjects, and gastrointestinal transit was accelerated in both PG and TG groups. An intense, precocious postprandial fullness and a relatively early recovery of hunger and prospective consumption sensations were seen in these patients. CONCLUSIONS: Patients with PG or TG have higher than predicted energy expenditure, which in TG seems to be compensated for by increased energy intake. These patients have preserved postprandial appetite responses and precocious postprandial fullness, which seem to be associated with disturbances in gastrointestinal transit of the ingested meal and are likely to be independent of vagal fiber integrity or stomach-released ghrelin.

Comparison between manual and automated techniques for assessment of data from dynamic antral scintigraphy.

OBJECTIVE: This work aimed at determining whether data from dynamic antral scintigraphy (DAS) yielded by a simple, manual technique are as accurate as those generated by a conventional automated technique (fast Fourier transform) for assessing gastric contractility. METHODS: Seventy-one stretches (4 min) of "activity versus time" curves obtained by DAS from 10 healthy volunteers and 11 functional dyspepsia patients, after ingesting a liquid meal (320 ml, 437 kcal) labeled with technetium-99m (99mTc)-phytate, were independently analyzed by manual and automated techniques. RESULTS: Data obtained by both techniques for the frequency of antral contractions were similar. Contraction amplitude determined by the manual technique was significantly higher than that estimated by the automated method, in both patients and controls. The contraction frequency 30 min post-meal was significantly lower in patients than in controls, which was correctly shown by both techniques. CONCLUSIONS: A manual technique using ordinary resources of the gamma camera workstation, despite yielding higher figures for the amplitude of gastric contractions, is as accurate as the conventional automated technique of DAS analysis. These findings may favor a more intensive use of DAS coupled to gastric emptying studies, which would provide a more comprehensive assessment of gastric motor function in disease.

Factors associated with abnormal gastric emptying in alcohol-related chronic pancreatitis.

BACKGROUND: Patients with alcohol-related chronic pancreatitis (ARCP) may present with abnormal gastric emptying (GE), which has been ascribed mainly to nutrient maldigestion. Nevertheless, many patients also have diabetes with autonomic dysfunction and malnutrition and the role of these factors on abnormal GE has not been investigated. GOALS: To determine the influences of malabsorption, diabetes, malnutrition, and autonomic dysfunction on GE abnormalities in patients with ARCP. STUDY: Forty ARCP outpatients and 18 healthy controls were studied. GE was measured by scintigraphy after a standard, liquid, nutrient meal labeled with Technetium-phytate. Autonomic function was evaluated by cardiovascular tests. The influence of each factor on abnormal GE was assessed by Bayesian multiple regression analysis. RESULTS: In the ARCP group, GE was abnormal in 19 patients (47.5%), who showed either accelerated (N=12) or delayed emptying (N=7). Diabetes was highly prevalent (P<0.01) in ARCP patients with either rapid or delayed GE (18/19). Multiple regression analysis showed that not only diabetes, but also autonomic dysfunction has significant effects on abnormal GE, whereas malabsorption and malnutrition seemed not to be associated to abnormal emptying. CONCLUSIONS: A substantial proportion of patients with ARCP may have abnormal GE. Either delayed or accelerated GE seem to be related to underlying diabetes mellitus and autonomic neuropathy rather than to nutrient malabsorption and malnutrition.

Dynamic antral scintigraphy following solid and liquid meals in healthy human subjects.

AIMS: Dynamic antral scintigraphy (DAS), a non-invasive technique for the assessment of post-prandial gastric contractions, has been used to demonstrate abnormal contractility in several clinical conditions. The objective of the present study was to assess differences between solid and liquid meals regarding gastric contractions in healthy volunteers using DAS. METHODS: Ten healthy male volunteers were studied after ingesting solid or liquid meals [approximately 1670 kJ (approximately 400 kcal)] labelled with 99mTc phytate and administered in a random order. Gastric images were acquired for 120 min for gastric emptying half-time (T1/2) measurement. Dynamic (1 frame x s(-1)) images of the gastric antrum were acquired at 30 min intervals for 4 min for the assessment of antral contractility. RESULTS: Gastric emptying T1/2 values for solid and liquid meals were similar (58.1+/-19.06 min vs. 69.4+/-6.76 min; P=0.13). For the solid meal, average values for both frequency (3.08+/-0.15 cycles x min(-1) vs. 2.78+/-0.18 cycles x min(-1); P=0.003) and amplitude (33.94+/-5.2% variation vs. 24.09+/-7.37% variation; P=0.002) of antral contractions were significantly higher than those obtained with the liquid meal. For either of the test meals, none of the antral contractility variables correlated with gastric emptying T1/2. CONCLUSIONS: Dynamic antral scintigraphy is capable of detecting differences between solid and liquid meals concerning post-prandial gastric antral contractions under physiological conditions. The frequency and amplitude of gastric antral contractions after a solid meal are greater than after an exclusively liquid meal of similar calorie content, in spite of lack of a difference regarding gastric emptying.

Participação de estudantes de medicina como avaliadores em exame estruturado de habilidades clínicas (Osce) / Participation of medical students as examiners in an objective structured clinical examination

Descrevem-se duas experiências realizadas com o objetivo de verificar se estudantes de Medicina de etapas avançadas podem ser utilizados em Osce para avaliar habilidades clínicas básicas de alunos iniciantes. Na primeira experiência, 6 internos e 6 professores avaliaram 59 alunos do currículo tradicional em Osce com 6 estações focadas na anamnese, exame físico e comunicação com o paciente. As notas dadas pelos professores foram maiores que as dos estudantes em todas as estações, exceto uma (comunicação), mas não houve diferenças significantes entre elas, exceto numa estação de exame físico (p < 0,001) (teste de Wilcoxon). Na segunda experiência, 15 internos do currículo tradicional e 9 professores avaliaram 58 estudantes do 1º ano, currículo PBL, em Osce com 3 estações para avaliar anamnese, exame físico e manipulação de luvas esterilizadas. Os estudantes foram pareados aos professores, e cada um fez sua avaliação individualizada usando o mesmo protocolo. Em metade das estações, os valores médios das notas de professores e estudantes foram significativamente diferentes. Isso aparentemente se deveu à variação significativa entre as notas dos professores, o que não ocorreu com relação às notas dadas pelos estudantes avaliadores (p < 0,05) (teste de Wilcoxon e Anova – Turkey, Dunn). Conclui-se que estudantes em fase de treinamento podem ser utilizados como examinadores confiáveis em exame de habilidades clínicas de estudantes iniciantes, sendo que a variabilidade entre as notas que atribuem para a mesma tarefa parece ser inferior à que se verifica nas notas dos professores.

Assessment of the post-prandial distribution of intragastric contents using an automated technique.

The distribution of intragastric contents has been studied using operator-dependent methods. We devised an automated technique for determining post-prandial intragastric distribution of radiolabeled meals, based on the calculation of the 'center of activity' (CA) of the radioactivity contained in the stomach in any given scintigraphic image. Twelve healthy volunteers and eleven functional dyspepsia (FD) patients ingested a liquid meal (320 mL, 450 kcal) labeled with (99m)Technetium-phytate. Images of the stomach were acquired every 5-10 min for 2 h, and counted to determine the percentage of total activity retained in the upper half of the stomach, as visually delineated. Each image was then processed using an algorithm for calculating a CA value representing the average of image-forming points corrected by pixel number. The relative CA position along the main longitudinal axis of the stomach, as defined by a digital 'skeletonizing' process, was expressed in a '0 to 1' scale. In the FD patients, the average of all CA determinations was significantly higher than in the controls (0.56, 0.30-0.80 versus 0.48, 0.33-0.68, p < 0.05) and correlated significantly with proximal stomach retention values assessed by a visual method (R = -0.64, p < 0.001). Assessing post-prandial intragastric distribution by a novel automated method is feasible and yields reliable data, while being much less operator dependent.

Relationships between intragastric food maldistribution, disturbances of antral contractility, and symptoms in functional dyspepsia.

We investigated the relationships between intragastric food maldistribution and antral dysmotility in functional dyspepsia, and whether these abnormalities relate to meal-induced symptoms. Intragastric distribution of food throughout gastric emptying was determined in patients (n = 24) and controls (n = 38) after a liquid nutrient meal labeled with (99m)technetium phytate. Antral contractility was also periodically assessed by dynamic scintigraphy and postprandial symptoms were monitored with visual analog scales. Residence of food in the proximal stomach was decreased in 8 (33%) and antral contractility was increased in 9 (37.5%) and decreased in 2 (8%) patients. Proximal and distal stomach motor abnormalities were neither significantly correlated nor associated. Increased antral contractility was significantly correlated (Rs = 0.54; P < .01) with postprandial nausea. We conclude that diminished residence of food in the proximal stomach and disturbed antral contractility occur independently in different subsets of functional dyspepsia patients. Increased antral contractility seems to play a role in postprandial nausea in functional dyspepsia.

Diminished retention of food in the proximal stomach correlates with increased acidic reflux in patients with gastroesophageal reflux disease and dyspeptic symptoms.

This work aimed at evaluating the intragastric distribution of food in patients with GERD and dyspepsia and its relationship to acidic reflux episodes. Gastric emptying and food retention in the proximal stomach were evaluated by scintigraphy in 12 healthy subjects and 19 patients with GERD and dyspepsia after a liquid test meal. Patients also underwent 24-hr esophageal pH monitoring, which included a 2-hr postprandial period following a similar test meal. Total gastric emptying was similar in patients and controls, whereas proximal gastric retention (AUCprox/AUCtot) was significantly decreased in patients (mean +/- SD: 0.48 +/- 0.07 vs. 0.56 +/- 0.06; P = 0.02). Within the GERD-dyspepsia group, a significant negative correlation was found between proximal gastric retention and the number of acidic reflux episodes. We concluded that abnormally decreased retention of gastric contents in the proximal stomach after a liquid meal may contribute to the pathogenesis of acidic reflux episodes in patients with GERD and dyspepsia.

Effects of myenteric denervation on gastric epithelial cells and gastric emptying.

The influence of myenteric denervation on gastric emptying and epithelial cell population was studied by chemical lesion of myenteric neurons of rat stomach with benzalkonium chloride. Three groups were evaluated: denervated, denervated with pyloroplasty, and control. After three months, the animals were submitted to functional (gastric emptying of liquids) and morphological (neuronal counting; mucosal area, height, and volume; mucous, chief, and parietal cell population; parietal cell area; and gastrin-G and somatostatin-D cell population) studies. After benzalkonium chloride treatment, there was significant delay in gastric emptying of liquids and an increase in mucosal area of all gastric portions, in antral mucosal volume, in parietal cell area, and gastrin-G cell and somatostatin-D cell populations. These changes did not occur when denervation was combined with pyloroplasty, indicating that after denervation, gastric distension and stasis are the major stimuli for parietal cell hypertrophy and G and D cell hyperplasia

Effect of isosorbide dinitrate and atropine of the lower esophageal sphincter pressure in chagasic patients

El efecto del dinitrato de isosorbide (5 mg, sublingual) y atropina (12 ug/Kg, i.v.) sobre la presión del esfínter inferior del esófago de pacientes chagásicos con compromiso esofágico y de un grupo control, fue estudiado por el método m,aanométrico. La presión fue medida cada 5 minutos por espacio de una hora después de haber administrado la referida substancia. Cuando el efecto del dinitrato de isosorbide fue estudiado, la presión del esfínter inferior fue de 15.3 ñ 1.9 mmHg (media ñ EEM) en pacientes chagásicos (N=5) y 25.4 ñ 5.6 mmHg en el grupo control (N=9) (P > 0,05). La reducción de la presión del esfínter es obtenida entre 10 a 20 minutos de la administración del dinitrato de isosorbitol por un tiempo de 40 minutos en los controles y de 5 a 60 minutos en los chagásicos (P < 0.05). En el grupo de chagásicos se apreció una reducción más intensa durante todo el tiempo en que fue medida la presión (P < 0.05). Cuando se estudió el efecto de la atropina, la presión del esfínter inferior fue de 20.6 ñ 1.8 en pacientes chagásicos (N=14) y 23.7 ñ 2.5 mmHg en los controles (N=9) (P > 0.05). La atropina reduce la presión del esfínter tanto en chagásicos como en individuos normales, pero más intensamente en el grupo control durante los primeros 30 minutos del estudio (P < 0.05). La acción de la propia musculatura puede ser el principal factor en el mantenimiento de la presión del esfínter en los pacientes chagásicos con participación secundaria del sistema colinérgico excitatorio

Effect of isosorbide dinitrate and atropine of the lower esophageal sphincter pressure in chagasic patients

El efecto del dinitrato de isosorbide (5 mg, sublingual) y atropina (12 ug/Kg, i.v.) sobre la presión del esfínter inferior del esófago de pacientes chagásicos con compromiso esofágico y de un grupo control, fue estudiado por el método m,aanométrico. La presión fue medida cada 5 minutos por espacio de una hora después de haber administrado la referida substancia. Cuando el efecto del dinitrato de isosorbide fue estudiado, la presión del esfínter inferior fue de 15.3 ñ 1.9 mmHg (media ñ EEM) en pacientes chagásicos (N=5) y 25.4 ñ 5.6 mmHg en el grupo control (N=9) (P > 0,05). La reducción de la presión del esfínter es obtenida entre 10 a 20 minutos de la administración del dinitrato de isosorbitol por un tiempo de 40 minutos en los controles y de 5 a 60 minutos en los chagásicos (P < 0.05). En el grupo de chagásicos se apreció una reducción más intensa durante todo el tiempo en que fue medida la presión (P < 0.05). Cuando se estudió el efecto de la atropina, la presión del esfínter inferior fue de 20.6 ñ 1.8 en pacientes chagásicos (N=14) y 23.7 ñ 2.5 mmHg en los controles (N=9) (P > 0.05). La atropina reduce la presión del esfínter tanto en chagásicos como en individuos normales, pero más intensamente en el grupo control durante los primeros 30 minutos del estudio (P < 0.05). La acción de la propia musculatura puede ser el principal factor en el mantenimiento de la presión del esfínter en los pacientes chagásicos con participación secundaria del sistema colinérgico excitatorio (AU)