Leptin enhances feeding suppression and neural activation produced by systemically administered bombesin

Leptin amplifies feeding inhibition and neural activation produced by either cholecystokinin or intragastric preloads, suggesting that leptin may increase the efficacy of gastrointestinal meal-related signals. To determine whether leptin would similarly potentiate the feeding inhibitory actions of another putative satiety peptide, we evaluated the effects of third ventricular leptin administration on food intake and c-Fos activation in response to systemically administered bombesin (BN). Leptin (3.5 microg) was administered 1 h before either 0.9% saline or BN (0.32 and 1.0 nmol/kg) followed by 30-min access to Ensure liquid diet. Although neither leptin nor 0.32 nmol/kg BN alone suppressed Ensure intake, the combination reduced intake by 28%. The higher BN dose (1.0 nmol/kg) produced a significant suppression by itself but was further enhanced in the presence of leptin. Consistent with the behavioral results, c-Fos activation in the nucleus of the solitary tract was increased by combined dosages of leptin and 0.32 nmol/kg BN beyond the individual response to either peptide. In the presence of leptin, BN produced a 3.4- to 5.2-fold increase in the number of c-Fos-positive cells in the nucleus of the solitary tract compared with when BN was given alone. These data provide further support for the hypothesis that the effect of leptin on food intake may be mediated, in part, by modulating meal-related satiety signals.

Clinical factors predicting fractures associated with an anterior shoulder dislocation

OBJECTIVES

To identify risk factors for fractures associated with an anterior shoulder dislocation treated in an emergency department (ED).

METHODS

A retrospective case-control study over five years of patients with an anterior shoulder dislocation was accomplished in a university-affiliated ED. Chart review identified possible predictors of fractures. Comparing the profile of patients having a clinically important fracture associated with their shoulder dislocation (cases) with those sustaining a noncomplicated dislocation (controls) provided the outcome measure.

RESULTS

A total of 334 patients were included in the study. Eighty-five (25.5%) had a clinically important fracture-dislocation, and the remaining 249 (74.5%) sustained a noncomplicated shoulder dislocation. Chi-square, logistic regression, and recursive partitioning analysis showed three significant factors for the presence of fracture-dislocation: 1) age 40 years or older, 2) a first episode of dislocation, and 3) mechanism of injury (i.e., a fall greater than one flight of stairs, a fight/assault episode, or a motor vehicle crash). A multiple logistic regression model estimated the significant adjusted odds ratios (and their 95% confidence intervals [95% CIs]) for each of the three factors: 5.18 (95% CI = 2.74 to 9.78), 4.23 (95% CI = 1.82 to 9.87), and 4.06 (95% CI = 1.95 to 8.48), respectively. A predictive model using any one of the three factors reached a sensitivity of 97.7% (95% CI = 91.8% to 99.4%), a specificity of 22.9% (95% CI = 18.1% to 28.5%), and a negative predictive value of 96.6% (95% CI = 88.3% to 99.6%).

CONCLUSIONS

Three risk factors predict clinically important fractures that are associated with shoulder dislocation: age, first episode, and mechanism of dislocation. A prospective validation may lead to standardized use of prereduction radiographs of the shoulder in the ED.

Meal-related stimuli differentially induce c-Fos activation in the nucleus of the solitary tract

Feedback signals arising from the oral cavity and upper gastrointestinal tract contribute to the control of meal size. To assess how these signals are integrated at central sites involved in ingestive control, we compared levels of c-Fos activation in the nucleus of the solitary tract (NTS) and area postrema (AP) in response to meal ingestion or gastric and duodenal infusions in the rat. Ingestion of a liquid diet to satiety induced significant fos-like immunoreactivity (FLI) at multiple levels of the NTS and within the AP. The restriction of intake to one-half the normal ingestion of a rat did not result in significant FLI, although gastric infusion of this liquid diet volume did. Fast bolus infusion resulted in greater FLI than did the same volume infused at a rate to mimic that of normal ingestion. Prior experience with gastric infusions did not affect the amounts of FLI within the NTS or AP. In rats with pyloric cuffs blocking flow from the stomach to the intestine, combined gastric load and duodenal nutrient elicited significantly greater FLI than either gastric or duodenal infusions alone. These data demonstrate that neural activation arising from meal-related stimuli are integrated at the level of the NTS.

Leptin amplifies the feeding inhibition and neural activation arising from a gastric nutrient preload

Leptin affects food intake by reducing meal size, suggesting that it may modulate the efficacy of within-meal satiety signals. To assess whether leptin would amplify the feeding inhibitory actions of a nutrient gastric preload, we compared liquid diet food intake and patterns of c-Fos activation in response to intraventricular leptin (3.5 microg), intragastric Ensure (10 ml over 10 min), or their combination. Leptin alone did not affect Ensure intake but significantly increased the suppression of intake produced by the intragastric preload. Within the nucleus of the solitary tract (NTS), leptin alone did not stimulate c-Fos but significantly elevated the number of c-Fos positive cells in response to intragastric Ensure at medial and rostral levels. Within the paraventricular nucleus (PVN), both leptin and the gastric load stimulated c-Fos expression, but the combination resulted in significantly greater number of c-Fos positive cells. These data demonstrate that leptin modulates the feeding inhibition produced by meal-related signals and suggest that this modulation occurs at the levels of the NTS and PVN.

Central leptin modulates behavioral and neural responsivity to CCK

The mechanisms through which leptin, the protein product of the ob gene, affects food intake remain to be determined. To assess whether the actions of leptin depend on modulation of within-meal satiety signals, we measured the effect of third ventricular leptin administration on the satiety actions of CCK. Leptin (10 micrograms) administered 1 h before 30-min access to a liquid diet had no effect on intake when administered alone, but doses of 3.5 or 10 micrograms dose dependently increased the suppression of intake produced by 1 nmol/kg CCK. Examination of patterns of c-Fos activation induced by 3.5 micrograms leptin and 1 nmol/kg CCK revealed that the combination produced significant c-Fos activation within the area postrema and the caudal and medial nucleus of the solitary tract (NST) compared with either leptin or CCK treatments alone. The leptin-CCK combination also resulted in increased c-Fos activation within the paraventricular nucleus of the hypothalamus above that produced by leptin alone. These data suggest that the actions of leptin in food intake are mediated through its ability to modulate responsivity to within-meal satiety signals.

Allelic loss of 9p21 and mutation of the CDKN2/p16 gene develop as early lesions during neoplastic progression in Barrett's esophagus

High frequency allelic loss of chromosome 9p21 has been reported in a number of human cancers, including those of the esophagus. The CDKN2 gene on chromosome 9p21 that encodes the p16 inhibitor of cyclinD/Cdk4 complexes is a target of allelic loss and inactivation in a variety of human cancers and cell lines. However, the roles of 9p21 allelic losses and CDKN2 mutations in human neoplastic progression in vivo remain controversial. We determined the prevalence of allelic loss at 9p21 and mutations in CDKN2 in esophageal adenocarcinomas and investigated the order in which they occurred relative to the development of aneuploidy and cancer during neoplastic progression. Aneuploid cell populations from 32 patients with Barrett's esophagus who had premalignant epithelium, cancer, or both, were purified by DNA content flow cytometric cell sorting and evaluated by polymerase chain reaction. Twenty-four of 32 informative patients (75%) had allelic loss at 9p21 in aneuploid cell populations. Premalignant epithelium was available for seven of the patients who had 9p21 allelic losses in cancer; allelic loss of 9p21 was detected before cancer in all seven (100%). Allelic loss of 9p21 preceded the development of aneuploidy in 13 of 15 patients (87%) who had aneuploid cell populations detected in premalignant epithelium, and the two events were detected simultaneously in the remaining two patients. Five of 22 aneuploid populations (23%) with 9p21 loss had somatic mutations in the remaining CDKN2 allele. The same mutations and 9p21 allelic losses were also found in the corresponding diploid cells from premalignant epithelium in all three cases that were evaluable. However, there was no evidence for mutation or homozygous deletion of p16 in the other 17 patients with 9p21 allelic loss. Our results indicate that 9p21 allelic losses and CDKN2 mutations develop as early lesions in diploid cells before aneuploidy and cancer during neoplastic progression in Barrett's esophagus.

Lead-contaminated house dust and urban children's blood lead levels

OBJECTIVES

This study assessed the relationship between lead-contaminated house dust and urban children's blood lead levels.

METHODS

A random-sample survey was used to identify and enroll 205 children, 12 to 31 months of age, who had resided in the same house since at least 6 months of age. Children's blood and household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for elevated blood lead (> or = 10 micrograms/dL).

RESULTS

Children's mean blood lead level was 7.7 micrograms/dL. In addition to dust lead loading (micrograms of lead per square foot), independent predictors of children's blood lead were Black race, soil lead levels, ingestion of soil or dirt, lead content and condition of painted surfaces, and water lead levels. For dust lead standards of 5 micrograms/sq ft, 20 micrograms/sq ft, and 40 micrograms/sq ft on noncarpeted floors, the estimated percentages of children having blood lead levels at or above 10 micrograms/dL were 4%, 15%, and 20%, respectively, after adjusting for other significant covariates.

CONCLUSIONS

Lead-contaminated house dust is a significant contributor to lead intake among urban children who have low-level elevations in blood lead. A substantial proportion of children may have blood lead levels of at least 10 micrograms/dL at dust lead levels considerably lower than current standards.

Risk and natural history of colonic neoplasia in patients with primary sclerosing cholangitis and ulcerative colitis

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) has been suggested as a risk factor for the development of colorectal cancer in ulcerative colitis (UC); however, previous studies of this association have been limited by small numbers of patients with PSC or have been performed retrospectively. This study prospectively evaluates the risk and natural history of colonic tumorigenesis in patients with PSC and UC and compares it with patients with UC without PSC.

METHODS

Twenty patients with PSC and UC and 25 control patients with UC were followed prospectively by colonoscopic surveillance using extensive mucosal biopsy sampling. All control patients with UC had disease extending beyond the sigmoid colon of > or = 8 years' duration; patients with PSC and UC were studied regardless of disease duration.

RESULTS

Forty-five percent (9 of 20) of the patients with PSC and UC had dysplasia compared with 16% (4 of 25) of the control patients with UC (P < or = 0.002). Prior liver transplantation did not affect the risk of colonic dysplasia. The time course for progression to dysplasia was similar between the patients with PSC and UC and the patients with UC; however, the patients with PSC and UC were five times more likely to develop dysplasia.

CONCLUSIONS

Patients with PSC and UC represent a subset of patients with UC who are at markedly increased risk for colonic neoplasia and who need close colonoscopic surveillance with extensive biopsy sampling.

A side-by-side comparison of dust collection methods for sampling lead-contaminated house dust

The Environmental Protection Agency is required to set a standard for lead-contaminated house dust, but whether dust lead loading (micrograms/ft2) or concentration (micrograms/g) is more predictive of children's blood lead levels, which dust collection method should be used, and which surfaces should be sampled are unknown. Using a random sample of sequential births, we enrolled 205 urban children, 12 to 30 months of age, who had lived in the same house since at least 6 months of age. Samples of dust were obtained from predetermined surfaces in each child's residence using a wipe method and two vacuum methods, the Baltimore repair and maintenance method (BRM) and the dust vacuum method (DVM). Other potential sources of environmental exposure also were analyzed for lead, including soil, water, and paint. In general, dust lead loading is more predictive of children's blood lead levels than is dust lead concentration. Dust lead loading as measured with the BRM sampler explained more of the variation in children's blood lead levels than did wipe loading and DVM loading (13.7, 10.1, and 5.9%, respectively, adjusted for other significant predictors). The partial correlation between BRM lead loading and children's blood lead was significantly different than that for DVM lead loading, but it was not significantly different than that for wipe lead loading. Of the four surfaces measured, noncarpeted floors and interior window sills or wells were significantly associated with children's blood lead levels in multiple regression models. These data indicate that dust lead loading is more predictive of children's blood lead levels than is dust lead concentration and that, to determine if a housing unit is safe for children, noncarpeted floors and interior window sills or window wells should be measured using either the BRM or wipe sampling method.

Long-term survival of medically treated patients in the Coronary Artery Surgery Study (CASS) Registry

BACKGROUND

This study describes the impact of clinical, angiographic, and demographic characteristics on the long-term survival of Coronary Artery Surgery Study (CASS) patients while they were under medical treatment. Revascularization rates for the population are also provided.

METHODS AND RESULTS

All CASS patients who had not received heart surgery before enrollment (23,467 patients) were included in this survival analysis while they were under medical treatment or surveillance. Follow-up time ranged from 0 to 17 years (median, 12 years). Long-term vital status is known for 95.8% of these patients. Log-rank tests, Kaplan-Meier survival curves, and Cox proportional-hazards regression are used to describe and assess the impact of patient characteristics on survival. Characteristics that had a significant impact on survival, in order of observed explanatory power, are age, number of diseased vessels, congestive heart failure score, smoking history, ejection fraction, sex, presence of left main coronary artery disease, presence of diabetes, left ventricular wall motion score, presence of other illnesses, history of myocardial infarction, and presence of left main equivalent disease. Overall, 12-year survival for patients with zero-, one-, two- and three-vessel disease is 88%, 74%, 59%, and 40%, respectively. Twelve-year survival for patients with at least one diseased vessel and ejection fractions in the ranges of 50% to 100%, 35% to 49%, and 0% to 34% is 73%, 54%, and 21%, respectively. High myocardial jeopardy, high anginal class, and two or three proximal diseased vessels characterize the profile of patients most likely to have received surgical treatment during follow-up.

CONCLUSIONS

These results contribute to the understanding of the natural history of coronary artery disease and are also of historical interest. The poor survival of patients with three-vessel disease and low ejection fractions continues to emphasize the importance of considering revascularization for these patients.

[Predictive value of preoperative acidity tests in ulcer recurrence after supraselective vagotomy]

The authors have analysed the predictive value of the basal and peak gastric acidity levels, measured preoperatively, in a series of 27 supraselective vagotomies. They recommend care in the choice of this operation for hypersecretors and they propose criteria for the preoperative selection of the candidates. They suggest determination of the preoperative basal gastric acidity level and a cimetidine suppression test to identify patients at high risk for recurrence of the ulcer.

[Psychoanalysis with the child.]

The author examines the specific nature of child psychoanalysis, its characteristics in Quebec and elsewhere, and the criteria for this kind of analysis. She analyses what distinguishes child psychoanalysis from other forms of therapy (including family therapy), its impact on the family as a whole, how the parents feel about the consultation, the importance of play and the imaginary world, and the process of treatment.