Drinking hot beverages is not associated with risk of oesophageal cancers in a Western population

We performed a nationwide population-based case-control study of hot beverage consumption and oesophageal cancer in Sweden. Drinking beverages very hot did not increase the risk for oesophageal squamous cell carcinoma, oesophageal adenocarcinoma, or gastric cardia adenocarcinoma.

Antioxidants and cancers of the esophagus and gastric cardia

Antioxidant vitamins have attracted considerable attention in previous studies of esophageal squamous-cell carcinoma, but dietary studies of adenocarcinoma of the esophagus and gastric cardia remain sparse. Treating these tumors as distinct diseases, we studied intakes of vitamin C, beta-carotene and alpha-tocopherol in a nationwide population-based case-control study in Sweden, with 185, 165, and 258 cases of esophageal adenocarcinoma, esophageal squamous-cell carcinoma, and gastric cardia adenocarcinoma, respectively, and 815 controls. Subjects with a high parallel intake of vitamin C, beta-carotene, and alpha-tocopherol showed a 40-50% decreased risk of both histological types of esophageal cancer compared with subjects with a low parallel intake. Antioxidant intake was not associated with the risk of gastric cardia adenocarcinoma. Separately, vitamin C and beta-carotene reduced the risk of esophageal cancers more than alpha-tocopherol. We found that antioxidant intake is associated with similar risk reductions for both main histological types of esophageal cancer. Our findings indicate that antioxidants do not explain the diverging incidence rates of the 2 histological types of esophageal cancer. Moreover, our data suggest that inverse associations with esophageal squamous-cell carcinoma and adenocarcinoma may be stronger among subjects under presumed higher oxidative stress due to smoking or gastroesophageal reflux, respectively. Our results may be relevant for the implementation of focused, cost-effective preventive measures.

Utility of on-site cytopathology assessment for bronchoscopic evaluation of lung masses and adenopathy

STUDY OBJECTIVES

To determine the extent to which on-site cytopathology assessment improves diagnostic yield when sampling lung nodules or masses and/or hilar or mediastinal lymphadenopathy by fiberoptic bronchoscopy (FOB).

DESIGN

Prospective cohort study.

SETTING

Two teaching hospitals in Baltimore, MD.

PATIENTS

Consecutive adult patients (>/= 18 years) undergoing FOB for evaluation of lung nodules or masses and/or hilar or mediastinal lymphadenopathy.

INTERVENTION

Prospective collection of data on patient factors and details of the procedure on standardized report forms.

MEASUREMENTS AND RESULTS

The primary outcome measure was a new diagnosis obtained by FOB. On-site assessment was used in 81 of 204 cases (40%), and overall diagnostic yield was 62%. Yield was greater when on-site cytopathology assessment was used, in unadjusted analysis (81% vs 50%, p < 0.001) and in a multivariate model (odds ratio, 4.5; 95% confidence interval, 2.1 to 10.0). Other significant predictors of a new diagnosis included older patient age, higher dose of narcotic used during FOB, and shorter procedure time.

CONCLUSIONS

We conclude that diagnostic yield was greater when on-site cytopathology was used to assist FOB evaluation of intrathoracic adenopathy and/or lung nodules or masses. Increasing the use of on-site cytopathology assessment may improve the quality of FOB services.

Relationships among dopamine transporter affinities and cocaine-like discriminative-stimulus effects

RATIONALE

The discriminative-stimulus effects of cocaine have been reported to be mediated by indirect agonist actions initiated by the blockade of dopamine uptake, and the potencies of drugs that have discriminative-stimulus effects like cocaine are directly related to their dopamine transporter binding affinities. The binding to the dopamine transporter by cocaine and many of its analogs has been reported to fit better using a two-site model than a one-site model.

OBJECTIVES

The present study examined the relationship among binding affinities of dopamine uptake inhibitors at these two sites and their potencies to produce discriminative-stimulus effects.

METHODS

The inhibition constants (K(i) values) were derived for unlabeled dopamine uptake inhibitors for displacement of [(3)H]WIN 35,428 from rat caudate putamen membranes. These K(i) values were related to the ED(50) values obtained in rats trained to discriminate 10 mg/kg cocaine from saline injections under a fixed-ratio 20 schedule of food reinforcement.

RESULTS

Among the dopamine uptake inhibitors studied, the binding data for eight compounds (WIN 35,428, nomifensine, WIN 35,981, WIN 35,065-2, methylphenidate, cocaine, cocaethylene, and bupropion) were better fit by a two-site model than a one-site model. The data for the remaining eleven compounds (RTI-31, RTI-55, RTI-121, RTI-32, LU19-005, BTCP, GBR12909, GBR12935, mazindol, LU17-133, and EXP561) were better fit by a one-site model. Of the drugs that were fit best by a two-site model, there was a higher correlation among the K(i) values for the high-affinity site and the ED(50) values (R(2)=0.655; P=0.015) than there was for the low-affinity site (R(2)=0.543; P=0. 037). Of the remaining drugs, there was a high correlation among the K(i) values and the ED(50) values for the discriminative-stimulus effects (R(2)=0.523; P=0.012).

CONCLUSIONS

These data suggest that the discriminative-stimulus effects of cocaine are more closely related to actions mediated by high-affinity binding to the dopamine transporter than they are to actions mediated by the low-affinity site. The further assessment of the respective contributions of high- and low-affinity binding to the behavioral effects of cocaine will be greatly enhanced with the development of pharmacological tools that have a high degree of selectivity for one of these components.

Asymmetric generalization between the discriminative stimulus effects of nicotine and cocaine

The discriminative stimulus effects of nicotine and cocaine were studied, alone and in combination, in rats. Two sets of rats were trained to press one lever when injected intraperitoneally (i.p.) with either nicotine (0.1 mg/kg = 0.6 micromol/kg, Set 1) or cocaine (8.9 mg/kg base = 29.4 micromol/kg, Set 2), and another lever when injected with saline. Rats learned to discriminate drug from saline, and maintained discriminative control throughout the study (at > 85% drug-appropriate responding). In accordance with most previous findings, cocaine only partially substituted for nicotine (maximum = 41% nicotine-lever responding). The nicotinic agonist, nornicotine, produced dose-related, near-full substitution for nicotine (maximum = 76% nicotine-lever responding), whereas the peripherally acting nicotinic agonist, methylcarbamylcholine, did not substitute for nicotine. The muscarinic receptor agonist pilocarpine also failed to substitute for nicotine. However, in the cocaine-trained rats, nicotine substituted fully for cocaine in a dose-dependent manner, demonstrating that cross-generalization between the two drugs is not symmetrical. Finally, administration of each drug as a pre-treatment to the other yielded inconsistent increases in each drug's discriminative stimulus effects. The results are congruent with the view that the discriminative stimulus effects of nicotine and cocaine share common features, but the asymmetric pattern of cross-generalization and the interactions revealed in the combination tests also suggest that there are important differences between them.

Lifestyle and endometrial cancer risk: a cohort study from the Swedish Twin Registry

Case-control studies of lifestyle factors have been inconclusive in the study of endometrial cancer, and prospective data are scarce. Our aim was to examine the associations of physical activity, weight and weight change, fruit, vegetable, and alcohol consumption, socio-economic status, parity and presence of diabetes mellitus with the risk of endometrial cancer in a cohort study. In 1967, 11,659 women in the Swedish Twin Registry, born 1886-1925, answered a 107-item questionnaire, including questions about diet, physical activity and other lifestyle factors. Complete follow-up through 1992 was attained through record linkage to the Swedish Cancer and Death Registers. The relative risks for endometrial cancer were estimated in proportional hazards models that adjusted confidence limits for correlated outcomes. We observed 133 incident cases of endometrial cancer in the cohort. There was no clear pattern of risk over strata of alcohol or fruit and vegetable intake, although the data suggest an increased risk with very low fruit and vegetable intake. Increasing physical activity markedly decreased the risk of endometrial cancer (p for trend < 0.01), independently of weight and parity; the risk in the highest quartile, relative to the sedentary category, was 0.2 (95% CI 0.3-0.8). As expected, higher weight in middle age increased the risk (p for trend < 0.01), as did higher weight in early adulthood. Contrary to previous findings, weight gain did not have an effect independent of weight at enrollment. We did not find a genetic component to endometrial cancer. Our results confirm that environmental factors are the most important, especially physical activity, parity, and weight in young and middle age.

High affinity binding of [3H]epibatidine to rat brain membranes

Several compounds, such as epibatidine, A-85380, and their analogs, have been identified recently as nAChR ligands whose affinities lie in the low picomolar range. Accurate measurement of such high affinities is fraught with certain technical difficulties, which may account for the inconsistency of previously reported affinities of epibatidine, ranging from 4 to 60 pM. Here, we demonstrate that (+/-)-[3H]epibatidine (1-500 pM) binds to a single population of sites in rat brain with KD of 8 +/- 2 pM. This affinity was confirmed in both kinetic experiments and competition assays with (+/-)-[3H]epibatidine and (-)-[3H]cytisine, which were performed under experimental conditions developed specifically for ligands with subnanomolar affinities. Variations from these conditions decreased the observed affinities.

Quality assessment through patient self-report of symptoms prefiberoptic and postfiberoptic bronchoscopy

STUDY OBJECTIVE

To apply the principles of quality improvement to measure the frequency and severity of symptoms that result from fiberoptic bronchoscopy (FOB), and to identify opportunities to improve FOB practice by identifying factors about patients and the process of care that predict these symptoms.

DESIGN

Concurrent longitudinal cohort study.

PATIENTS

Four hundred ninety-three adult patients who underwent FOB.

MEASUREMENTS AND RESULTS

Patients completed questionnaires just prior to FOB and again at 48 h postprocedure. Patients were asked to rate the severity of nose pain, throat pain, swallowing pain, and chest pain, and the frequency of coughing, hemoptysis, phlegm, shortness of breath, wheezing, difficulty swallowing, fever, and chills. Symptom severity was reported on a four-point ordinal scale.

FINDINGS

Significant worsening was found for nose pain, throat pain, swallowing pain, and hemoptysis. Shorter patients experienced more throat pain and hemoptysis, and longer procedure time predicted nose pain and hemoptysis.

CONCLUSIONS

Bronchoscopy causes nose pain, throat pain, swallowing pain, and hemoptysis to a larger extent than previously has been recognized. There are opportunities to improve the patient experience with bronchoscopy by using smaller bronchoscopes in shorter patients, shortening the procedure length, and reanesthetizing the nares in longer procedures.

Amphetamine-induced conditioned activity and sensitization: the role of habituation to the test context and the involvement of Pavlovian processes

Behaviours associated with drug action can sometimes be elicited, in the absence of drug, by exposure to stimuli that were present during drug administration. Such a finding is usually interpreted as a conditioned drug effect. Often, however, the outcome could arise if drug administration in a particular environment retarded behavioural habituation to that environment. To test the 'habituation hypothesis' of conditioned drug effects, mice received 10 daily injections of d-amphetamine ('paired' group) or saline ('unpaired') in test boxes, and the converse injections in the colony room. Another group received saline in both environments. The apparatus and procedures yielded minimal habituation of behaviours (ambulation and rearing) over sessions. Only the paired group demonstrated behavioural sensitization, indicating environment-specific sensitization. The paired group also showed more ambulation and rearing than the others on the critical test of conditioning (saline injection in test box); moreover, their conditioning test scores were higher than those of the other groups on their first exposure to the test boxes, contradicting the habituation hypothesis. Further supporting the involvement of Pavlovian conditioning, levels of ambulation and rearing measured for 10 min before each injection increased in the paired group, relative to the unpaired groups, over successive pairing sessions. Tests controlling for differential handling/injection experience produced results consistent with those previously obtained. Together, the findings are incompatible with the habituation hypothesis, and further support the role of Pavlovian conditioning.

How mature is your organization's prevention effort? Four stages of managed care health promotion

Rooted in prevention since the 1973 HMO Act, managed care has weathered seasons enough to put down roots in patient education and preventive services. Now it shows a readiness for re-potting. For health promotion to reach full maturity and realize its highest calling, its roots need to spread into the community. Analysts have posited four stages of managed care market penetration; similarly, I propose four stages of maturation in managed care-based prevention initiatives (Table 1). These stages of prevention are based on an analysis of more than 100 presentations from a series of "Managed Care to Managed Health" conferences sponsored by The Institute for Research and Education, Health-System Minnesota in Minneapolis. The following descriptions of the stages of maturation illustrate the development of prevention efforts--from patient education and preventive services in early stages to improving the health of enrollees and ultimately the community in later stages.

Protective effect of fruits and vegetables on stomach cancer in a cohort of Swedish twins

Observational studies, primarily of a case-control design, have shown an inverse association of fruit and vegetable consumption with the risk of stomach cancer, a finding tentatively attributed to anti-oxidant vitamins. Ensuing randomized-intervention trials of these vitamins, however, have been mostly negative. Therefore, the seemingly protective effect of fruit and vegetables in case-control studies is suspected to be influenced by the information bias inherent in the retrospective assessment of exposure, particularly since pre-conceptions about the wholesome effects of these foods are common among the public. Our aim was to examine the association of fruit and vegetable intake with the risk of stomach cancer in a prospective cohort study. Fruit and vegetable consumption was assessed in 1967 in 11,546 individuals in the Swedish Twin Registry, along with a wide range of potentially confounding factors. Complete follow-up through 1992 was attained through record linkage to the National Cancer and Death Registers. The relative risk of stomach cancer was estimated in proportional hazards models, with confidence intervals (CIs) adjusted for correlated outcomes. The risk of stomach cancer was inversely related to fruit and vegetable consumption. Controlling for potentially confounding factors, the relative risk among subjects with the lowest compared to those with the highest intake was 5.5 (95% CI 1.7-18.3) with a statistically significant dose-risk trend (p < 0.05). Our results indicate that information bias is not likely to explain the discrepancy between the results of observational studies and of randomized-intervention trials.

Protective effect of fruits and vegetables on stomach cancer in a cohort of Swedish twins

Observational studies, primarily of a case-control design, have shown an inverse association of fruit and vegetable consumption with the risk of stomach cancer, a finding tentatively attributed to anti-oxidant vitamins. Ensuing randomized-intervention trials of these vitamins, however, have been mostly negative. Therefore, the seemingly protective effect of fruit and vegetables in case-control studies is suspected to be influenced by the information bias inherent in the retrospective assessment of exposure, particularly since pre-conceptions about the wholesome effects of these foods are common among the public. Our aim was to examine the association of fruit and vegetable intake with the risk of stomach cancer in a prospective cohort study. Fruit and vegetable consumption was assessed in 1967 in 11,546 individuals in the Swedish Twin Registry, along with a wide range of potentially confounding factors. Complete follow-up through 1992 was attained through record linkage to the National Cancer and Death Registers. The relative risk of stomach cancer was estimated in proportional hazards models, with confidence intervals (CIs) adjusted for correlated outcomes. The risk of stomach cancer was inversely related to fruit and vegetable consumption. Controlling for potentially confounding factors, the relative risk among subjects with the lowest compared to those with the highest intake was 5.5 (95% CI 1.7-18.3) with a statistically significant dose-risk trend (p < 0.05). Our results indicate that information bias is not likely to explain the discrepancy between the results of observational studies and of randomized-intervention trials.

The dopamine D4 receptor antagonist L-745,870: effects in rats discriminating cocaine from saline

The contribution of dopamine D4 receptors to the discriminative stimulus effects of cocaine was evaluated by testing the selective dopamine D4 receptor antagonist, L-745,870 (3-([4-(4-chlororphenyl) piperazin-1-yl] methyl)-1 H-pyrrolo[2,3-b] pyridine), alone and in combination with cocaine, in rats trained to discriminate cocaine (10 mg/kg) from saline. The antagonist (1-10 mg/kg) failed to engender cocaine-appropriate responding when injected alone, and failed to modify the cocaine dose-response curve when injected as a pre-treatment; however, it reduced response rates dose-dependently. Conversely, the dopamine 'D1-like' receptor antagonist, SCH 39166 ((-)-trans-6,7,7a,8,9, 13b-hexahydro-3-chloro-2hydroxy-N-methyl-5H-benzo[d]napth o-¿2,1-b¿azepine, produced surmountable antagonism. Results suggest that dopamine D4 receptors play a negligible role in cocaine's discriminative stimulus effects, and further support a critical involvement of dopamine D1-like receptors.

Dopaminergic mediation of the discriminative stimulus effects of bupropion in rats

Bupropion is a novel, non-tricyclic antidepressant with a primary pharmacological action of monoamine uptake inhibition. The drug resembles a psychostimulant in terms of its neurochemical and behavioural profiles in vivo, but it does not reliably produce stimulant-like effects in humans at clinically prescribed doses. Bupropion binds with modest selectivity to the dopamine transporter, but its behavioural effects have often been attributed to its inhibition of norepinephrine uptake. This experiment examines monoaminergic involvement in the discriminative stimulus effects of bupropion. Rats were trained to press one lever when injected i.p. with bupropion (17.0 mg/kg), and another lever when injected with saline. In substitution tests, dose-response curves were obtained for several monoamine uptake inhibitors. Nine of ten dopamine uptake blockers fully substituted for bupropion; the exception, indatraline (LU 19-005), partially substituted (71% bupropion-appropriate responding). Serotonin and norepinephrine uptake blockers (zimelidine and nisoxetine, respectively) produced negligible or limited substitution, and the anti-muscarinic dopamine uptake blocker benztropine produced limited partial substitution. A series of dopamine D1-like and D2-like receptor agonists were also tested: only the D2-like agonist RU 24213 fully substituted; three other D2-like agonists and four D1-like agonists partially substituted (50% < drug responding < 80%). Antagonism of the discriminative effects of bupropion was obtained with a D1- and a D2-like dopamine antagonist. The results demonstrate strong similarities with those obtained using other dopamine uptake inhibitors as training drugs, and support the view that the behavioural effects of bupropion are primarily mediated by dopaminergic mechanisms.

Conditioned grooming induced by the dopamine D1-like receptor agonist SKF 38393 in rats

Stimulation of dopamine D1-like receptors reliably increases grooming in rats and mice. The study examined whether the grooming response elicited by the prototypical D1-like agonist SKF 38393 (8 mg/kg s.c.) could be conditioned to the specific environment in which it occurred. Rats in one group (Paired) received SKF 38393 and rats in another group (Unpaired) received saline in observation boxes outside of their housing room; the rats were then scored for duration and frequency of grooming bouts over 25 min. The ordering of injections was reversed the next day in the rats, housing room. The procedure was repeated twice, with at least one intervening drug-free day, to give three conditioning trials. The D1-like agonist significantly increased grooming on each of the three conditioning trials, without obvious tolerance or sensitization, and the effect tended to persist for the duration of each trial. On the test trial for conditioned grooming, mean grooming duration was significantly greater in the Paired than the Unpaired group, suggesting that SKF 38393-induced grooming had been conditioned to the test environment. This is the first time that drug-elicited grooming has been conditioned to environmental cues.

Dopamine 'D2-like' receptor agonists in combination with cocaine: absence of interactive effects on locomotor activity

This study examined interactions between cocaine and drugs that act as direct agonists at subtypes of "D2-like" dopamine receptors. The drugs 7-OH-DPAT, quinpirole and RU24213 were studied alone and in combination with cocaine for their effects on locomotor activity in non-habituated mice. Locomotor activity was measured by photobeam crossings over 140 min. At the doses given (7-OH-DPAT: 0.006-6.4 mg/kg; quinpirole: 0.001-1 mg/kg; RU24213: 0.008-8 mg/kg) all three direct agonists dose-dependently reduced locomotor activity throughout the test, whereas cocaine (0.6-20 mg/kg) produced dose-related hyperactivity. Next, for each direct agonist, a series of doses was selected (up to threshold behaviourally-active doses) as pretreatments to a sub-maximally stimulant dose of cocaine (15 mg/kg). 7-OH-DPAT and quinpirole did not modulate the effects of cocaine; RU24213 produced, at best, a very modest attenuation of the effects of cocaine. Finally, a series of cocaine doses (below stimulant threshold) was given before a single dose of each direct agonist (the lowest dose to reduce activity significantly). Cocaine did not reliably alter the hypoactivity produced by any of the D2-like agonists. By demonstrating negligible interactions between cocaine and D2-like agonists, the results fail to demonstrate any necessary involvement of D2-like receptors in one of the behavioural effects of cocaine.