Responses of domestic fowl to repeated +Gz acceleration

The responses of domestic fowl to repeated exposures of 4 min to +6Gz (8 times daily, 5 d weekly) are reported. Survivorship curves for the test group of 48 birds divided into three response categories: mode I, highly susceptible, with all individuals dying on the first day; mode II, more tolerant, with mortality occurring within the first 20 d of treatment; and mode III, highly tolerant, with mortality occurring only after 20 d of treatment. Observations of lymphocyte frequency, an index of systemic stress, and postmortem observations indicate that this heterogeniety has a biological basis.     

A 4-year follow-up study of a rural community with endemic Chagas' disease

The paper reports on a 4-year follow-up study that represents the continuation of a previous cross-sectional study on Chagas'' disease carried out in a rural community (Belén) in Venezuela. The earlier study included 1210 persons all over 5 years of age out of a total of 1656 inhabitants and demonstrated a high prevalence of Chagas'' infection (47.3%) and a high rate of Chagas'' disease seropositivity among those with chronic myocardial heart disease (84.8%); heart disease was found in 17.3% of persons studied. The follow-up study was based on 812 persons and established that in the sample the frequency of Chagas'' infection was 16.3% and that of heart disease 2.2%. Clinical, electrocardiographic and radiological analyses were made on patients with previous heart disease as well as on new patients. Different evolutive electrocardiographic patterns have been found, including variations ranging from normal to definitively abnormal.     

The Study of Exercise and Nutrition in Older Rhode Islanders (SENIOR): translating theory into research

Innovative and effective health promotion interventions targeted on older adults within a public health framework will be increasingly important as the US population ages dramatically. The benefits of healthier lifestyles for older adults include increased functional ability and improved quality of life. The Study of Exercise and Nutrition in Older Rhode Islanders (SENIOR) Project is a multibehavioral health promotion intervention for community-dwelling older adults focusing on increasing exercise and fruit and vegetable consumption. Intervention materials are stage-tailored for each individual, and include manuals, newsletters, expert system assessments and reports, and telephone coaching. The primary purpose of the SENIOR Project is to investigate the relative effectiveness of a multiple-behavior intervention-based on a single theoretical framework-compared to single-behavior interventions. The secondary purposes are to investigate the intervention's effects on both functional ability and general health outcomes, and how older adults move along a continuum of changing health behaviors. The Transtheoretical Model of Health Behavior Change, the conceptual framework for the SENIOR Project, was chosen for the following reasons: performance potential with older adults, individual tailoring on a stage basis, technological features, and interdisciplinary research base and community partnership.     

Physiological studies on neurons in the dorsal cochlear nucleus of cat

Results reported here support the conclusion that an individual neuron in the dorsal cochlear nucleus (DCN) can exhibit pauser, buildup, and chopper patterns in response to tone pips. Fusiform cells have been previously identified as the principal cell exhibiting these patterns. Fusiform cells can also exhibit an onset response followed by suppression of spontaneous activity at their characteristic frequency (CF). Off CF only suppression is seen. These neurons are characterized by a restricted excitatory region near threshold. All these cells can exhibit nonmonotonic rate curves, narrow excitatory regions, and inhibitory sidebands. Nonmonotonicity occurred in 34% of pausers, 52% of buildup, 89% of onsets with a graded response, and 50% overall in the DCN cells. Chopper units occur as often as the other types combined in the DCN. Only 14% show nonmonotonic rate curves. Those with high-spontaneous activity also show inhibitory sidebands. Cells with a predominant buildup pattern occur most frequently in the fusiform cell layer, whereas pausers occur throughout the DCN below the molecular layer. Intracellular potentials often reflect the average response pattern. Sharply delimited response areas indicate that these cells may be useful for performing a spectral analysis. These cells show almost no phase locking suggesting that temporal encoding is an unlikely function. It is suggested that the effects of anesthetic on the function of the DCN is not as marked as previously indicated.     

Tolerance of domestic fowl to high sustained +Gz.

A system is described for the acceleration treatment of domestic fowl. A reasonable endpoint for acceleration tolerance is provided by a bradycardia which occurs fairly close to the lethal limit. In a group of 61 male Rhode Island Red chickens exposed to 6 Gz, the mean tolerance (+/- S.D.) was 11.1 +/- 10.6 min. Among individuals, the acceleration tolerance is inversely related to both body size and age, and positively to pre-treatment heart rate.     

Encoding timing and intensity in the ventral cochlear nucleus of the cat

Physiological response properties of neurons in the ventral cochlear nucleus have a variety of features that are substantially different from the stereotypical auditory nerve responses that serve as the principal source of activation for these neurons. These emergent features are the result of the varying distribution of auditory nerve inputs on the soma and dendrites of the various cell types within the nucleus; the intrinsic membrane characteristics of the various cell types causing different responses to the same input in different cell types; and secondary excitatory and inhibitory inputs to different cell types. Well-isolated units were recorded with high-impedance glass microelectrodes, both intracellularly and extracellularly. Units were characterized by their temporal response to short tones, rate vs. intensity relation, and response areas. The principal response patterns were onset, chopper, and primary-like. Onset units are characterized by a well-timed first spike in response to tones at the characteristic frequency. For frequencies less than 1 kHz, onset units can entrain to the stimulus frequency with greater precision than their auditory nerve inputs. This implies that onset units receive converging inputs from a number of auditory nerve fibers. Onset units are divided into three subcategories, OC, OL, and OI. OC units have extraordinarily wide dynamic ranges and low-frequency selectivity. Some are capable of sustaining firing rates of 800 spikes/s at high intensities. They have the smallest standard deviation and coefficient of variation of the first spike latency of any cells in the cochlear nuclei. OC units are candidates for encoding intensity. OI and OL units differ from OC units in that they have dynamic ranges and frequency selectivity ranges much like those of auditory nerve fibers. They differ from one another in their steady-state firing rates; OI units fire mainly at the onset of a tone. OI units also differ from OL units in that they prefer frequency sweeps in the low to high direction. Primary-like-with-notch (PLN) units also respond to tones with a well-timed first spike. They differ from onset cells in that the onset peak is not always as precise as the spontaneous rate is higher. A comparison of spontaneous firing rate and saturation firing rate of PLN units with auditory nerve fibers suggest that PLN units receive one to four auditory nerve fiber inputs. Chopper units fire in a sustained regular manner when they are excited by sound.(ABSTRACT TRUNCATED AT 400 WORDS)     

Late outcome of isolated gastric bypass

OBJECTIVE: To complete a long-term (>5 years) follow-up of patients undergoing isolated gastric bypass for severe obesity. SUMMARY BACKGROUND DATA: Previous experience as well as randomized trials suggested that the ideal operation for obesity should rely on manipulation of satiety rather than the production of malabsorption. Such an operation should incorporate a small gastric pouch of less than 30 mL placed in a dependent position on the lesser curvature of the stomach, not dependent on staples, and separated from the remaining stomach with a retrocolic, retrogastric Roux-en-Y gastrojejunostomy without external support. METHODS: The authors established an obesity clinic where patients were seen six times during the first year and semiannually thereafter. Emphasis was placed on defining success in terms of approximation to normal body-mass index. RESULTS: Of 274 patients, 243 (89%) were followed up for 5.5 +/- 1.5 years. Before surgery, the patients were obese (n = 13), morbidly obese (n = 134), or super-obese (n = 96). The obese and morbidly obese group achieved an excellent result, and the super-obese a good result. Individual results showed considerable variation from the mean. CONCLUSIONS: This study of isolated gastric bypass with a 5.5-year follow-up rate of 88.6% revealed a success rate of 93% in obese or morbidly obese patients and 57% in super-obese patients. Isolated gastric bypass compares favorably with biliopancreatic diversion in terms of weight loss, maximum weight loss, weight regain, current body-mass index, and percentage of patients with a body-mass index less than 35 kg/m2.     

Perceptions and beliefs about body size, weight, and weight loss among obese African American women: a qualitative inquiry.

The purpose of this qualitative study was to explore perceptions and beliefs about body size, weight, and weight loss among obese African American women in order to form a design of weight loss intervention with this target population. Six focus groups were conducted at a community health clinic. Participants were predominantly middle-aged with a mean Body Mass Index of 40.3 +/- 9.2 kg/m(2). Findings suggest that participants (a) believe that people can be attractive and healthy at larger sizes; (b) still feel dissatisfied with their weight and self-conscious about their bodies; (c) emphasize eating behavior as the primary cause for weight gain; (d) view pregnancy, motherhood, and caregiving as major precursors to weight gain; (e) view health as the most important reason to lose weight; (f) have mixed experiences and expectations for social support for weight loss; and (g) prefer treatments that incorporate long-term lifestyle modification rather than fad diets or medication.