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PubMed2003

Effect of diet and Helicobacter pylori infection to the risk of early gastric cancer.

BACKGROUND: The association of dietary habits and Helicobacter pylori infection with early gastric cancer is still unclear. METHODS: A hospital-based case-control study was conducted in Korea. Sixty-nine patients were newly diagnosed as having early gastric cancer at the Division of Gastroenterology, Asan Medical Center, and 199 healthy subjects who visited the Health Promotion Center of the this same hospital for annual health examinations were selected as controls. Helicobacter pylori infection status was assayed by ELISA, and information for dietary habits was obtained by interview using a semi-quantitative food frequency questionnaires. Preference for salty taste was also evaluated using a sensitive test. RESULTS: H. pylori seropositivity was observed in 88% of cases, as compared with 75% of controls (OR = 5.3, 95% confidence interval:1.7-16.5). Adaptive salt concentration was significantly and positively associated with early gastric cancer risk (p < 0.01). Decreased risks of early gastric cancer were observed in association with intakes of clear broth, raw vegetables, fruits, fruit or vegetable juices, and soybean curds. On the other hand, a high intake of salt-fermented fish and kimchi were associated with an elevated risk of early gastric cancer. Subjects with positive H. pylori infection and a high salty preference had a 10-fold higher risk of early gastric cancer than subjects without H. pylori infection and with a low salty preference (p for interaction = 0.047). CONCLUSION: Some dietary factors and H. pylori infection are significantly associated with early gastric cancer. In particular, high-salty diets may enhance the effect of H. pyori infection in gastric carcinogenesis.

Adult↗
PubMed2004

Effect of liquid flavor supplementation of the diet on dairy cows in the transition period.

A 9-wk trial was conducted to study the performance of 24 Holstein cows during the transition period (3 wk prepartum to 6 wk postpartum). Cows were assigned to either a control or liquid-flavored (0.52 mL/kg of feed) total mixed ration in a randomized complete block design. The diets contained corn silage, alfalfa haylage, cottonseed, and a grain mix based on ground corn and soybean meal. Cows were fed to ensure 10% orts, and the diet provided (on a dry matter basis) 13% crude protein, 32% acid detergent fiber, 44% neutral detergent fiber, and 1.54 Mcal/kg of NEL prepartum and 17.5% crude protein, 30% acid detergent fiber, 40% neutral detergent fiber, and 1.57 Mcal/kg of NEL postpartum. An additional 2.3 kg of alfalfa hay was fed during the first 5 d postpartum. Weekly means of dry matter intake (DMI), milk yield, milk protein, milk fat, SNF, somatic cell counts, and body weight (BW) were analyzed using a repeated measures procedure. There was no effect of treatment on these variables, and least squares means were 16.9 and 15.7 kg/d for DMI, 38 and 35.3 kg/d for milk yield, 3.10 and 3.11% for milk protein, 3.69 and 3.74% for milk fat, 8.37 and 8.16% for SNF, 1.99 x 10(5) and 4.33 x 10(5) for somatic cell count, and 631 and 651 kg for BW for cows fed control and flavored diets, respectively. Individual cow daily DMI data were fitted to an exponential model describing pre- and postpartum feed consumption [DMI = a - b x e(-c x t), where DMI was measured in kg, a = asymptotic DMI, b = potential fractional increase in DMI, c = fractional rate of increase in DMI, and t = days prior to calving or days in milk]. Fractional rates of increase in DMI were similar: 0.139 and 0.123/d for control and flavored diets, respectively. Data for both groups were separately analyzed using multiple regression with 3.5% fat-corrected milk as the dependent variable and BW and DMI as independent variables. More BW was mobilized per unit increase in 3.5% fat-corrected milk in cows fed the control than in cows fed the flavored diet. Cows fed the control diet tended to be in more negative energy balance during early lactation than cows fed the flavored diet. It was concluded that feeding flavor improved energy balance of cows in early lactation and may reduce the risk of health or reproductive problems.

Animal Feed↗
PubMed1985

Outcome of pregnancy in the rat with mild hyperphenylalaninaemia and hypertyrosinaemia: implications for the management of "human maternal PKU".

In attempting to determine the effects of mildly elevated maternal phenylalanine (Phe) blood levels on the developing fetal rat brain, a dietary supplement of Phe was given, under taste cover of Aspartame. Phe and tyrosine (Tyr) levels were mildly elevated throughout pregnancy without evidence of malnutrition. Mild hyperphenylalaninaemia with concurrent hypertyrosinaemia induced in rats prior to conception resulted in microcephaly and lasting behavioural problems in the offspring, specifically hyperactivity and learning difficulties. Dams fed Tyr to produce Tyr levels equivalent to the Phe-fed animals showed only the learning difficulties among the offspring. alpha-Methyl Phe, a Phe hydroxylase inhibitor, fed in conjunction with Phe, at the level relevant to these experiments, resulted in raised Tyr levels and does not provide a better method of determining whether mildly elevated maternal Phe levels alone, or Phe and Tyr in combination, cause the abnormality found in the offspring of Phe-supplemented dams. Therapeutic addition of Tyr to diets of mothers with even mild hyperphenylalaninaemia should be approached with caution as mild co-elevation of Phe and Tyr in the fetus may be harmful. In the face of such a possible therapeutic dilemma alternatives, such as dietary additions of other essential amino acids to limit fetal brain damage, need to be explored.

Animals↗
PubMed1994

No effect of oral or sample temperature on sensory assessment of fat content.

This work examined the possible influences of oral and sample temperature on the perception of fat content of a model food system. Melting or related phenomena may contribute to the greater sensation of fat content and the highly acceptable textural characteristics associated with certain fats. Thirty-one adults assessed the fat content of 0%, 12%, 24%, 36%, and 48% oil-in-water emulsions prepared with a commercial cocoa butter substitute having a melting range of 17-41 degrees C. Samples were evaluated at combinations of sample and mouth temperatures of 20 and 36 degrees C, with oral temperatures manipulated by repeated cold- and warm-water rinses prior to assessments. There were no significant differences amongst these treatments on perceived fat content of the samples, nor were subject characteristics of age or body composition related to judgments of fat content in these stimuli. Although previous studies had shown that degree of fat saturation is associated with enhanced perception of fat content (11), that does not appear to be related to the degree or occurrence of melting in the mouth over the ranges studies here.

Adolescent↗
PubMed2003

A randomized, placebo-controlled trial of topiramate in amyotrophic lateral sclerosis.

OBJECTIVE: To determine if long-term topiramate therapy is safe and slows disease progression in patients with ALS. METHODS: A double-blind, placebo-controlled, multicenter randomized clinical trial was conducted. Participants with ALS (n = 296) were randomized (2:1) to receive topiramate (maximum tolerated dose up to 800 mg/day) or placebo for 12 months. The primary outcome measure was the rate of change in upper extremity motor function as measured by the maximum voluntary isometric contraction (MVIC) strength of eight arm muscle groups. Secondary endpoints included safety and the rate of decline of forced vital capacity (FVC), grip strength, ALS functional rating scale (ALSFRS), and survival. RESULTS: Patients treated with topiramate showed a faster decrease in arm strength (33.3%) during 12 months (0.0997 vs 0.0748 unit decline/month, p = 0.012). Topiramate did not significantly alter the decline in FVC and ALSFRS or affect survival. Topiramate was associated with an increased frequency of anorexia, depression, diarrhea, ecchymosis, nausea, kidney calculus, paresthesia, taste perversion, thinking abnormalities, weight loss, and abnormal blood clotting (pulmonary embolism and deep venous thrombosis). CONCLUSIONS: At the dose studied, topiramate did not have a beneficial effect for patients with ALS. High-dose topiramate treatment was associated with a faster rate of decline in muscle strength as measured by MVIC and with an increased risk for several adverse events in patients with ALS. Given the lack of efficacy and large number of adverse effects, further studies of topiramate at a dose of 800 mg or maximum tolerated dose up to 800 mg/day are not warranted.

Adult↗
PubMed2003

Physical and emotional stress have differential effects on preference for saccharine and open field behaviour in rats.

Stress may influence the sensitivity of subjects to rewarding stimuli and stress modality may differentially affect this sensitivity. This relation was investigated in our animal model using chronic physical (repeated mild foot shocks) and emotional (witness) stress. Previous research has established that the two stressors have differential long-term effects on behaviour, where physical stress caused inactivity in a small open field and emotional stress hyperactivity. Rats were stressed on 5 consecutive days and tested for locomotor activity in a small open field (day 10) and saccharine preference (day 11). The preference for graded concentrations of saccharine over water was used as a measure for their sensitivity to reward. Physical stress treatment induced a long-term decrease both in preference for saccharine and open field activity compared to control treatment. Emotional stress animals showed an increase in open field behaviour activity and a slight increase in saccharine preference. Physical stress seems to cause anhedonia, while emotional stress might cause an increased sensitivity to reward. In conclusion, stress can induce differential long-term effects on sensitivity to positive stimuli and the response to novelty depending on stress modality.

Adaptation, Psychological↗
PubMed2006

Tobacco chippers show robust increases in smoking urge after alcohol consumption.

OBJECTIVE AND RATIONALE: Heavy social drinkers often engage in occasional cigarette smoking, especially in the context of consuming large quantities of alcohol. The current study assessed alcohol's effects on smoking urge as a function of alcohol dose and time course in tobacco chippers with heavy social drinking patterns. METHOD: The study assessed 39 chippers who underwent three separate evening sessions. Each subject received a placebo (1% volume alcohol as a taste mask), a low alcohol dose (two to three drinks equivalent), and a high alcohol dose (four to five drinks equivalent) in random order. No smoking was permitted during the sessions and the participants were abstinent from smoking for at least 3 h before arrival. Throughout the session, cigarette craving was assessed by the Brief Questionnaire of Smoking Urges and alcohol response was assessed by the Biphasic Alcohol Effects Scale (BAES). RESULTS: The results showed that alcohol significantly increased cigarette craving in a dose-dependent manner (p<0.001). At the high alcohol dose, craving was heightened during the rising portion of the blood alcohol curve (BAC). There was a strong relationship between BAC and craving for positive reinforcement and this relationship was partially mediated by BAES stimulation, but not sedation. CONCLUSIONS: The findings show that alcohol directly increases smoking urge in chipper smokers. Tobacco chippers may crave cigarettes more during heavier than during lighter drinking bouts, and this effect appears to be driven by heightened stimulation levels rather than as a means to offset alcohol's sedative effects.

Adult↗
PubMed2005

Real-time flavor release from French fries using atmospheric pressure chemical ionization-mass spectrometry.

Flavor release from French fries was measured with atmospheric pressure chemical ionization-mass spectrometry (APCI-MS) using both assessors (in vivo) and a mouth model system (in vitro). Several volatiles measured with APCI were identified with MS-MS. The effect of frying time, salt addition, and an alternative process using superheated steam was determined on I(max) (maximum intensity of compounds) and on t(max) (time of maximum intensity). In vitro a "chewing" frequency of 0.60 Hz caused an increased t(max) for low molecular weight compounds compared to the other frequencies tested. Above 0.93 Hz further increase in the frequency did not affect t(max). Trends observed with in vivo experiments could be verified with in vitro experiments. I(max) correlated well with frying time. Addition of salt resulted in a decreased t(max), suggesting a salting-out effect. The alternative process caused a layer of oil on the surface, and this resulted in a higher t(max), but no effect on I(max) was found. This phenomenon may be critical for the sensory quality and would not have been observed with static volatile measurements, demonstrating the value of flavor release measurements.

Food Handling↗
PubMed2001

Chemical sensor based on nonlinearity: principle and application.

Novel chemical sensors based on a time-dependent nonlinear response are reviewed. The strategy is to artificially mimic information transduction in living organisms. In taste and olfaction, information of chemical structure and concentration is transformed into nervous impulses in the nervous cell, i.e., time-dependent multi-dimensional information. Because the excitation and pulse generation in the nervous cell are typically nonlinear phenomena, it may be worthwhile to utilize the nonlinearity as the multi-dimensional information for molecular recognition. The principle of a "nonlinear" sensor is that a sinusoidal modulation is applied to a system, and the output signal is analyzed. The output signal of the sensor is characteristically deformed from the sinusoidal input depending on the chemical structure and concentration of the chemical stimuli. The characteristic nonlinear responses to chemical stimuli are discussed in relation to the kinetics of chemical compounds on the sensor surface. As a practical application, we introduced electrochemical sensors based on the differential capacitance, semiconductor gas sensors under the application of sinusoidal temperature or diffusion change, and a chemical sensor based on the spatio-temporal information. We demonstrated that mutli-dimensional information based on nonlinearity can provide quite useful information for the analysis of chemical species, even in the presence of another analyte or an interference with a single detector.

Artificial Organs↗
PubMed1995

Tomato juice, chocolate drink, and other fluids suppress volitional drinking of alcohol in the female Syrian golden hamster.

Although the hamster generally prefers alcohol at a level similar to that of the rat or mouse selectively bred to consume alcohol, the drinking hamster demonstrates neither physical dependence on alcohol nor elevated blood levels of alcohol, which are two typical criteria characterizing an animal model of alcoholism. The present investigation was designed to determine whether a third criterion of an animal model (i.e., consumption of high levels of alcohol in the presence of a palatable fluid, fulfilled by the P rat) would be met by the female Syrian golden hamster (Mesocricetus auratus). A standard 3-bottle preference test was undertaken in 6 female hamsters over an 11 day period, in which water was presented in one tube and, in a second tube, a v/v solution of alcohol which was increased in concentration from 3% to 50% on each day as follows: 3%, 5%, 7%, 9%, 12%, 15%, 20%, 25%, 30%, 40%, and 50%. Then each hamster was offered its individually determined, maximally preferred concentration of alcohol for 4-8 days, which was 20%, 25%, or 30% alcohol. The mean absolute intake of alcohol during this period was 17.9 +/- 1.1 g/kg per day, whereas the mean proportion of alcohol to total fluid was 0.68 +/- 0.05. Then over a 4-day interval, a solution of tomato juice, peach juice, mango juice, dextrose and a chocolate beverage (Ensure Plus), all made isocaloric to the alcohol solutions with dextrose, was placed in the third tube simultaneously with water and the individually preferred concentration of alcohol.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Drinking↗
PubMed2002

Multidisciplinary examination of patients with illness attributed to dental fillings.

OBJECTIVE AND METHODS: In 1993, a special Amalgam Clinic was established at Huddinge University Hospital. Residents in the Stockholm County area with morbidity attributed to dental fillings ('amalgam disease'), were referred to this clinic. Patients were examined by a dentist (n 428), a physician (n 379), and a psychologist (n 360). Sixty-nine per cent were women and 31% men; the mean patient age was 46 years. RESULTS: Oral symptoms included tender or aching teeth (60%), metallic taste (54%), sore mouth (43%) and dry mouth (43%). Signs of moderate or severe temporomandibular joint dysfunction were found in 81 cases, glossitis in 30 and oral lichen in 26 cases. Common general symptoms included diffuse pain (78%), general weakness (75%), extreme fatigue (68%) and dizziness (68%). Seven per cent of the patients suffered from previously undiagnosed medical conditions (thyroid dysfunction, anaemia, cardiopathy, renal disease, cancer). In 26 subjects, skin patch testing revealed allergy to mercury, gold or palladium. The median concentration of mercury was 10 nmol L-1 in whole blood, 3 nmol L-1 in plasma and 10 nmol L-1 in urine, i.e. normal levels. Earlier mental trauma was common, and in the psychological questionnaire SCL-90, clear tendencies to somatization were found. Only a few cases of severe psychiatric illness were observed. No positive correlation was found between the amount of amalgam and somatic symptoms or psychological effect parameters. CONCLUSIONS: The results do not support the hypothesis that release of mercury from amalgam fillings is the cause of 'amalgam disease', but suggest that there may be various explanations for the patient's complaints.

Acute Disease↗
PubMed2003

Nonexercise muscle tension and behavioral fidgeting are positively correlated with food availability/palatability and body weight in rats.

While certain measures of energy expenditure such as respiratory quotient and thermogenesis are readily quantifiable using existing animal models, the mechanism for and measurement of energy expenditure via nonexercise activity have not been thoroughly characterized. This low intensity form of physical exertion, associated with involuntary fidgeting and postural changes in man, was quantified in the present studies using passive measurement of muscle tension in rats. In particular, long-term weight loss and gain were induced using diet yoking and feeding of preferred foods in order to assess corresponding changes in locomotor activity and radiotelemetered measures of muscle tension, temperature and global activity. Hind limb muscle tension, but not body temperature, was increased 30-60% by enhancing the availability or palatability of food relative to the decreased muscle tension resulting from limited food availability. Enhancing food availability or palatability also produced a relative 5-15% increase in the amount of telemetered global activity. Importantly, neither diet yoking nor provision of a highly preferred diet altered a precise measure of behavioral locomotor activity. These results suggest that muscle tension and activity-in-place are positively correlated with weight change in the present studies and that these mechanisms of energy expenditure are mobilized by environmental changes in diet composition and meal pattern.

Animal Feed↗
PubMedDate not supplied

Bioinformatical analysis of G-protein-coupled receptors.

G-protein-coupled receptors play a key role in cellular signaling networks that regulate various physiological processes, such as vision, smell, taste, neurotransmission, secretion, inflammatory, immune responses, cellular metabolism, and cellular growth. These proteins are very important for understanding human physiology and disease. Many efforts in pharmaceutical research have been aimed at understanding their structure and function. Unfortunately, because they are difficult to crystallize and most of them will not dissolve in normal solvents, so far very few G-protein-coupled receptor structures have been determined. In contrast, more than 1000 G-protein-coupled receptor sequences are known, and many more are expected to become known soon. In view of the extremely unbalanced state, it would be very useful to develop a fast sequence-based method to identify their different types. This would no doubt have practical value for both basic research and drug discovery because the function or binding specificity of a G-protein coupled receptor is determined by the particular type it belongs to. To realize this, a statistical analysis has been performed for 566 G-protein-coupled receptors classified into seven different types. The results indicate that the types of G-protein-coupled receptors are predictable to a considerable accurate extent if a good training data set can be established for such a goal.

Algorithms↗
PubMed1988

A physicist looks at bacterial chemotaxis.

What is distinctive about bacterial chemotaxis, as compared to, for example, taste in the elephant, is the time over which decisions must be made. The lower limit is set by diffusion of chemicals to and from the cell surface, which demands long times for statistically significant counts. The upper limit is set by diffusion of the cell itself, which demands short times for well-defined swimming paths. For an organism the size of E. coli, temporal comparisons of the concentrations of chemicals in the environment must be made within a few seconds. Although such short time spans might be difficult for the biochemist, they are not so difficult for E. coli, because diffusion can carry a small molecule across the cell in about 1 msec. E. coli has the opposite problem: How does it integrate inputs from many receptors over periods 1000 times as long? The mechanisms for this signal processing are beginning to be understood. We know how most chemical attractants are identified, how temporal comparisons might be made, and how the behavioral output is effected. We know less about how sensory information crosses the cytoplasmic membrane, how the reactions that link the receptors to the flagella generate such high gain, and what actually controls the direction of flagellar rotation. One thing is quite clear: E. coli demands our admiration and respect.

Chemotaxis↗
PubMedDate not supplied

Olfactory learning in individually assayed Drosophila larvae.

Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction and olfactory learning. The brain of adult Drosophila, however, is still complex. We therefore chose to work on the larva with its yet simpler but adult-like olfactory system and provide evidence for olfactory learning in individually assayed Drosophila larvae. We developed a differential conditioning paradigm in which odorants are paired with positive ("+" fructose) or negative ("-" quinine or sodium chloride) gustatory reinforcers. Test performance of individuals from two treatment conditions is compared-one received odorant A with the positive reinforcer and odorant B with a negative reinforcer (A+/B-); animals from the other treatment condition were trained reciprocally (A-/B+). During test, differences in choice between A and B of individuals having undergone either A+/B- or A-/B+ training therefore indicate associative learning. We provide such evidence for both combinations of reinforcers; this was replicable across repetitions, laboratories, and experimenters. We further show that breaks improve performance, in accord with basic principles of associative learning. The present individual assay will facilitate electrophysiological studies, which necessarily use individuals. As such approaches are established for the larval neuromuscular synapse, but not in adults, an individual larval learning paradigm will serve to link behavioral levels of analysis to synaptic physiology.

Animals↗
PubMed2005

Induction of cAMP response element-binding protein-dependent medium-term memory by appetitive gustatory reinforcement in Drosophila larvae.

The fruit fly Drosophila melanogaster has been successfully used as a model animal for the study of the genetic and molecular mechanisms of learning and memory. Although most of the Drosophila learning studies have used the adult fly, the relative complexity of its neural network hinders cellular and molecular studies at high resolution. In contrast, the Drosophila larva has a simple brain with uniquely identifiable neural networks, providing an opportunity of an attractive alternative system for elucidation of underlying mechanisms involved in learning and memory. In this paper, we describe a novel paradigm of larval associative learning with a single odor and a positive gustatory reinforcer, sucrose. Mutant analyses have suggested importance of cAMP signaling and potassium channel activities in larval learning as has been demonstrated with the adult fly. Intriguingly, larval memory produced by the appetitive conditioning lasts medium term and depends on both amnesiac and cAMP response element-binding protein (CREB). A significant part of memory was disrupted at very early phase by CREB blockade without affecting immediate learning performance. Moreover, we also show that synaptic output of larval mushroom body neurons is required for retrieval but not for acquisition and retention of the larval memory, including the CREB-dependent component.

Animals↗
PubMed2005

Neuroendocrine and cytokine profile of chronic mild stress-induced anhedonia.

A bidirectional relationship exists between depression and cardiovascular disease. Patients with major depression are more likely to develop cardiac events, and patients with myocardial infarction and heart failure are more likely to develop depression. A feature common to both clinical syndromes is activation of proinflammatory cytokines and stress hormones, including the hypothalamic-pituitary-adrenal axis and the renin-angiotensin-aldosterone system. In the present study we examined the hypothesis that exposure to chronic mild stress (CMS), an experimental model of depression that induces anhedonia in rats, is sufficient to activate the production of proinflammatory cytokines and stress hormones that are detrimental to the heart and vascular system. Four weeks of exposure of male, Sprague-Dawley rats to mild unpredictable environmental stressors resulted in anhedonia which was operationally defined as a reduction in sucrose intake without a concomitant effect on water intake. Humoral assays indicated increased plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), plasma renin activity, aldosterone, and corticosterone in the CMS exposed rats. Tissue TNF-alpha and IL-1beta were increased in the hypothalamus, and TNF-alpha was increased in the pituitary gland. These humoral responses to CMS, associated with anhedonia as an index of depression in the rat, are likely to be associated with neurohumoral mechanisms that may contribute to adverse cardiac events. The findings provide a basis for examining more directly the interactions among the central, endocrine, and immune systems in depression associated with heart disease.

Aldosterone↗
PubMed1998

Estrous cycle effects on operant responding for ethanol in female rats.

Human females have been reported to be uniquely sensitive to the deleterious effects of ethanol, thus it is important to study the characteristics of and mechanisms underlying alcohol consumption that may be specific to females. Models of ethanol self-administration in female rats that take into consideration the estrous cycle have the potential to provide important information concerning these characteristics and mechanisms. The purpose of this study was to explore the effect of the cycle on ethanol self-administration using a limited access operant paradigm. Female Wistar rats were trained to lever press for 10% ethanol versus water using a saccharin fading procedure. Responses were examined across the four phases of the estrous cycle. No effects of estrous cycle phase were observed when these rats were allowed to cycle freely. Subsequently, estrous phase effects were investigated in females whose cycles had been synchronized. Under this condition, an effect of estrous phase was present, with lower ethanol intake observed in estrus (and in some cases proestrus). Synchronized rats all showed at least one very clear 4-day estrous cycle, whereas free-running rats' cycles ranged from 3 to 5 days. Thus, it is more likely that synchronized rats were tested in the identical portion of each phase, when hormone levels were less variable. These results suggest that ethanol may be more reinforcing during diestrus than proestrus and estrus in female rats.

Alcohol Drinking↗