The relationship between self-rated health, stress, health care, overall quality of life and weight in a rural population.

OBJECTIVE: To determine if there is a relationship between self-rated health, stress, health care, satisfaction, overall quality of life scores and weight. DESIGN: A mailed survey and retrospective chart review of people living in the Bella Coola Valley who attend the Bella Coola Medical Clinic. STUDY POPULATION: Adults living in the Bella Coola Valley who are registered with the Bella Coola Medical Clinic. MAIN OUTCOME MEASURES: Self-rated health, stress, health care received, satisfaction with health, happiness, overall quality of life scores and weight (body mass index). RESULTS: An estimated 1734 residents live in the Bella Coola and are registered with the clinic. A total of 968 useable surveys were returned for a response rate of 56% (968/1734). Nine hundred and eighteen survey respondents had a recent weight in kilograms documented; 803 survey respondents had a height documented. A higher weight was associated with poorer self-rated health, higher stress levels, and lower satisfaction with health. It was also associated with lower self-esteem and satisfaction scores, particularly in younger obese people. A higher weight was not correlated with spirituality, overall quality of life, health care rating, or happiness scores. CONCLUSION: Increasing weight may contribute to poorer health, higher stress, lower satisfaction with health and poorer self-esteem. However, we found no evidence that increased weight impairs happiness or overall quality of life. This may be one reason for the lack of success of weight loss strategies that focus on happiness and overall quality of life to increase readiness and motivation. Alternatively, focussing on secondary medical benefits and self-esteem may be useful.

Endurance and performance during multiple intense high +Gz exposures with effective anti-G protection.

BACKGROUND: In many high-intensity wartime scenarios, pilots may be required to fly multiple, strenuous missions during the same day. HYPOTHESIS: New anti-G protection allows fighter pilots to endure multiple high +G, exposures during several sorties in a limited time interval. METHODS: Nine well-trained centrifuge subjects were exposed to tactical aerial combat maneuvers using balanced pressure breathing during G (PBG) and an extended coverage anti-G suit. The centrifuge exposures consisted of five simulated sorties during a 4-h period, each consisting of four engagements with rapid onset cycles (6 G x s(-1)) varying between +4 G, and -9 GC. The subjects executed a tracking task before, during, and after each engagement and verbally indicated their effort level. Neck muscle strength was measured before and after the test. RESULTS: Seven of the nine subjects could endure all five sorties during the 4-h period. On a scale from 0 (no effort) to 11 (maximum possible effort), highest effort level during runs varied from 5.5 to 11 units (mean 8.7). Maximal heart rate varied from 140-173 bpm (mean 159) and minimum finger oxygen saturation from 75-93% (mean 88). Maximal peripheral and central light-loss varied from 0 to 100% (mean 71 and 40, respeclively). Three G-LOCs (two in the same subject) and four cases of near loss of consciousness occurred. The general fatigue recovery time varied from 9 to 48 h (mean 21). The tracking tests showed that performance deteriorated significantly during all G exposures; the neck muscle contraction was impaired by 12% (p = 0.035) after the C exposures. CONCLUSION: It is possible to train subjects to withstand five simulated flight sorties during a 4-h period with a total of up to 80 peaks to +9 Gz and 80 peaks to +8 Gz using PBCG and an extended coverage anti-G suit.

Ankle biomechanics during four landing techniques.

PURPOSE: An understanding of landing techniques is important for the prevention of injuries in a number of athletic events. There is a risk of injury to the ankle during landings, and the kinematics and forces involved in different landing strategies may be related to the occurrence of trauma. METHODS: In the current study, four drop conditions from a 30.48-cm (12-inch) height were tested. The conditions were a) BN: Bent knee (self-selected), Natural (self-selected) plantar flexor contraction; b) SN: Stiff-knee, Natural plantar flexors; c) SP: Stiff-knee, Plantar flexors absorbing the impact; and d) SH: Stiff-knee, absorbing most of the impact in the Heels. Peak vertical forces and accelerations were measured, and Achilles tendon forces and stiffnesses were calculated. RESULTS: Peak vertical forces and peak tibial accelerations were highest for the SH condition (2418 N and 20.7 G), whereas peak Achilles tendon force was highest for SP drops. The overall average AT stiffness was 166,345 N x m(-1). CONCLUSIONS: The results from the study were used in an extensive cadaver study to investigate ankle injuries. The data from the current study indicate that athletes may not use their full energy absorbing potential in landings during sporting activities.

Prosthetic arm monitoring system using a programmable interface controller.

Children with upper extremity limb deficiency are often prescribed a prosthetic arm to assist with daily function. Three types of prostheses are available: passive, active body-powered, and active myoelectric; costs range from $3,000 to $15,000. Clinicians rely on parent and child feedback regarding the usefulness of the prosthesis, and may assess the child's skill in using the device in a controlled setting. However, these methods do not provide an objective quantification of the wear and use of the device during daily activities. The purpose of this project is to develop a sensor to record the amount of time per day the prosthetic arm is worn, and to count the number of times per day the child activates (closes) the prosthetic hand (or terminal device). The system that has been developed can be integrated unobtrusively into a child's prosthetic arm. A programmable interface controller (PIC) with interface circuitry and memory was developed to record the daily wear pattern and hand usage of the prosthesis at 15-minute intervals. Memory and battery capacities are sufficient to record data over a three-month period. A personal computer interface downloads the collected data and may be used to reprogram the device for different time periods of data collection. All components, including the battery, have a mass of 87 grams and fit inside the forearm cavity of a 9-year old's prosthesis. Controlled trials are underway at Shriners Hospital for Children, Northern California, to determine system reliability.

Pressurized sleeves and gloves for protection against acceleration-induced arm pain.

BACKGROUND: Acceleration (or G) induced arm pain may develop in centrifuge runs and in flight with low arm position and assisted pressure breathing during G (PBG) in combination with an extended coverage anti-G suit. To decrease this arm pain, pressurized sleeves and gloves were developed. METHODS: Eight subjects who earlier exhibited G-induced arm pain were tested on the centrifuge. The G-exposures consisted of a gradual onset run up to a maximum of +9 G2, rapid onset runs to +3, +4, +5, +6, +7, +8, and +9 Gz and a simulated aerial combat maneuver (SACM) with peaks up to +9 Gz. On separate days, the subjects were tested without the sleeves and gloves, and with the sleeves and gloves pressurized to a maximum of 40, 60, or 80 mmHg at +9 Gz. The subjects reported their left and right arm pain on a subjective rating scale. RESULTS: G-induced arm pain, usually starting above +6 Gz, was often the reason for termination of the G-exposure without the pressurized sleeves and gloves. The pressurized sleeves and gloves significantly (p < 0.001) decreased arm pain, put no significant difference was found among the different pressures used. Heart rate was not different with and without the pressurized sleeves and gloves. CONCLUSIONS: The pressurized sleeves and gloves are an effective method to alleviate and sometimes eliminate G-induced arm pain.

Ankle biomechanics during impact landings on uneven surfaces.

Inversion sprains of the lateral ligaments of the ankle are one of the most common of all sporting injuries. While the strains in the anterior talofibular (ATFL) and calcaneofibular (CFL) ligaments have been measured in quasi-static conditions, the dynamic strains during an actual traumatic event have not been determined. The present investigation determined the strains and strain rates in the ATFL and CFL during an in vitro inversion sprain. The ATFL tended to have higher strain and strain rate values than the CFL, which may explain why it is more often injured than the CFL.

A biomechanical analysis of a medial unloading brace for osteoarthritis in the knee.

OBJECTIVES: The goals of the study were to measure the force applied to the lateral side of the knee by a valgus loading brace designed for patients with medial compartment osteoarthritis (OA) and to compare the varus moment at the knee during level gait with and without the brace. METHODS: Five subjects diagnosed with medial compartment OA were fitted with a custom Monarch valgus loading knee brace. A 3-dimensional videobased motion analysis system and force plate information were used to calculate forces and moments at the knee. An instrumented condylar bladder was used to determine the force applied to the knee by the brace. The varus moments for the braced and unbraced trials were compared during gait at 15%, 20%, 25%, and 30% of stance. RESULTS: The Monarch brace significantly reduced the varus moment at 20% and 25% of stance. The valgus force measured with the custom condylar bladder remained fairly constant throughout the first 80% of the stance phase. CONCLUSIONS: The reduced various moment observed for the braced condition demonstrates the biomechanical function of the brace in 5 subjects and may contribute to a reduction of pain for patients with medial compartment OA.

Recombinant leptin for weight loss in obese and lean adults: a randomized, controlled, dose-escalation trial.

CONTEXT: The protein hormone leptin is important to the homeostatic regulation of body weight. Treatment with exogenous leptin may affect weight loss. OBJECTIVE: To determine the relationship between increasing doses of exogenous leptin administration and weight loss in both lean and obese adults. DESIGN: A randomized, double-blind, placebo-controlled, multicenter, escalating dose cohort trial conducted from April 1997 to October 1998. SETTING: Four university nutrition and obesity clinics and 2 contract clinical research clinics. PARTICIPANTS: Fifty-four lean (body mass index, 20.0-27.5 kg/m2; mean [SD] body weight, 72.0 [9.7] kg) and 73 obese (body mass index, 27.6-36.0 kg/m2; mean [SD] body weight, 89.8 [11.4] kg) predominantly white (80%) men (n = 67) and women (n = 60) with mean (SD) age of 39 (10.3) years. INTERVENTIONS: Recombinant methionyl human leptin self-administered by daily morning subcutaneous injection (0 [placebo], 0.01, 0.03, 0.10, or 0.30 mg/kg). In part A, lean and obese subjects were treated for 4 weeks; in part B, obese subjects were treated for an additional 20 weeks. Lean subjects consumed a eucaloric diet to maintain body weight at the current value, and obese subjects were prescribed a diet that reduced their daily energy intake by 2100 kJ/d (500-kcal/d) from the amount needed to maintain a stable weight. MAIN OUTCOME MEASURES: Body weight, body fat, and incidence of adverse events. RESULTS: Weight loss from baseline increased with increasing dose of leptin among all subjects at 4 weeks (P = .02) and among obese subjects at 24 weeks (P = .01) of treatment. Mean (SD) weight changes at 4 weeks ranged from -0.4 (2.0) kg for placebo (n = 36) to -1.9 kg (1.6) kg for the 0.1 mg/kg dose (n = 29). Mean (SD) weight changes at 24 weeks ranged from -0.7 (5.4) kg for the 0.01 mg/kg dose (n = 6) to -7.1 (8.5) kg for the 0.30 mg/kg dose (n = 8). Fat mass declined from baseline as dose increased among all subjects at 4 weeks (P = .002) and among obese subjects at 24 weeks of treatment (P = .004); more than 95% of weight loss was fat loss in the 2 highest dose cohorts at 24 weeks. Baseline serum leptin concentrations were not related to weight loss at week 4 (P = .88) or at week 24 (P = .76). No clinically significant adverse effects were observed on major organ systems. Mild-to-moderate reactions at the injection site were the most commonly reported adverse effects. CONCLUSIONS: A dose-response relationship with weight and fat loss was observed with subcutaneous recombinant leptin injections in both lean and obese subjects. Based on this study, administration of exogenous leptin appears to induce weight loss in some obese subjects with elevated endogenous serum leptin concentrations. Additional research into the potential role for leptin and related hormones in the treatment of human obesity is warranted.

Muscle activity in the slalom turn of alpine skiing and in-line skating.

The electromyographic (EMG) activity of seven muscles of the trunk and lower extremity in five male masters level ski racers during a slalom turn in both alpine skiing and in-line skating was recorded using a telemetry system. Measurements were made on separate testing days using slopes commonly used in each activity (24 slope alpine skiing, 5 in-line skating). Qualitative video recorded at 60 Hz was analyzed to partition the turning cycle in both slalom skiing and in-line skating into initiation and turning phases. The EMG data from each turning cycle were normalized to standard isometric contractions (SIC's) for each muscle in order to quantitatively compare the amplitude characteristics of each phase of the turning cycle in both slalom skiing and in-line skating. The turning phase of in-line skating was found to be significantly longer (55%) than in slalom skiing, most likely due to significantly lower subject velocities recorded during in-line skating (8.5 m/s vs 10.2 m/s). All muscles were active at moderate to high levels (48-172% of SIC) during each phase of the turning cycle in both slalom skiing and in-line skating. The EMG amplitude characteristics were similar for six of the muscles in both slalom skiing and in-line skating for each of the turning phases. Only the erector spinae displayed significantly higher average and peak amplitudes in slalom skiing for both phases. It is concluded that the muscle activity patterns associated with the slalom turn of in-line skating are similar but notably more quasi-static than in slalom skiing.

Nucleic acid vibrational circular dichroism, absorption, and linear dichroism spectra. II. A DeVoe theory approach.

The DeVoe polarizability theory is used to calculate vibrational circular dichroism (VCD) and infrared (IR) absorption spectra of four polyribonucleotides: poly(rA) x poly(rU), poly(rU) x poly(rA) x poly(rU), poly(rG) x poly(rC), and poly(rC+) x poly(rI) x poly(rC). This is the first report on the use of the DeVoe theory to calculate VCD, oriented VCD, IR absorption, and IR linear dichroism (LD) spectra of double- and triple-stranded polyribonucleotides. Results are reported for DeVoe theory calculations--within the base-stretching 1750-1550 cm(-1) spectral region--on several proposed multistranded polyribonucleotide geometries. The calculated spectra obtained from these proposed geometries are compared with previously reported measured and calculated VCD and IR spectral results. Base-base hydrogen-bonding effects on the frequencies and magnitudes of the base carbonyl stretching modes are explicitly considered. The good agreements found between calculated and measured spectra are proposed to be further evidence of the usefulness of the DeVoe theory in drawing three-dimensional structural conclusions from measured polyribonucleotide VCD and IR spectra.

Nucleic acid vibrational circular dichroism, absorption, and linear dichroism spectra. I. A DeVoe theory approach.

Infrared (IR) vibrational circular dichroism (VCD), absorption, and linear dichroism (LD) spectra of four homopolyribonucleotides, poly(rA), poly(rG), poly(rC), and poly(rU), have been calculated, in the 1750-1550 cm-1 spectral region, using the DeVoe polarizability theory. A newly derived algorithm, which approximates the Hilbert transform of imaginaries to reals, was used in the calculations to obtain real parts of oscillator polarizabilities associated with each normal mode. The calculated spectra of the polynucleotides were compared with previously measured solution spectra. The good agreement between calculated and measured polynucleotide spectra indicates, for the first time, that the DeVoe theory is a useful means of calculating the VCD and IR absorption spectra of polynucleotides. For the first time, calculated DeVoe theory VCD and IR absorption spectra of oriented polynucleotides are presented. The calculated VCD spectra for the oriented polynucleotides are used to predict the spectra for such measurements made in the future. The calculated IR spectra for the oriented polynucleotides are useful in interpreting the linear dichroism of the polynucleotides.

Endogenous amylase levels and response to supplemental feed enzymes in male turkeys from hatch to eight weeks of age.

Amylase and xylanase enzyme concentrations in the pancreas, small intestine, and crop were measured in Nicholas male poults fed diets with and without supplemental amylase and xylanase from 0 to 8 wk of age. Eight birds from each of three diets (control, amylase-supplemented, xylanase-supplemented) were killed every 3 d to determine the amylase and xylanase activity within the pancreas, small intestine, and crop. Pancreatic organ weight was not affected by diet, indicating an absence of dietary amylase effect upon pancreatic tissue growth. Pancreatic amylase activity was not consistently affected by diet. Amylase activity within the intestinal chyme increased sporadically with dietary amylase supplementation over the control and xylanase-supplemented diets. Increasing supplemental amylase activity levels may provide more conclusive evidence of an additive effect of dietary amylase and endogenous amylase activity. Xylanase supplementation within the feed did not affect endogenous amylase activity.

Effects of protein level and enzyme supplementation upon growth and rate of digesta passage of male turkeys.

An experiment was conducted to determine the effect of feeding enzyme supplements (Avizyme and protease) at two levels of dietary crude protein (24 and 28%) to male turkeys from 0 to 5 wk of age. The Avizyme-protease enzyme mixture was fed at five concentrations within each protein level in an effort to determine an optimal level of supplementation. Enzymes were added to the 24% protein diet to determine whether the supplements would enhance the growth performance of birds fed the lower protein diet to the level of those fed the 28% protein diet. Rate of passage was evaluated to determine whether an ANF effect corresponded to enzyme concentration or protein level. Dietary protein level significantly influenced growth. Birds fed the 28% protein diet had improved body weight gain, feed consumption, and feed efficiency of 11.5, 6.5, and 4.4%, respectively, when compared with birds fed the 24% protein diet. Enzyme addition to the 24% protein corn-soybean meal diet produced a graded response but did not improve growth over the control. Although enzyme supplementation improved poult utilization of the 24% protein diet, growth and feed utilization were not equal to the performance of the poults fed the 28% protein diet. When the enzyme mixture was added to the 28% diet, performance was not consistently altered. Rate of digesta passage was not different between the levels of dietary protein or among levels of enzyme supplementation, indicating that the applied protein levels did not deleteriously affect nutrient utilization.

Growth and intestinal morphology of male turkeys as influenced by dietary supplementation of amylase and xylanase.

Three diets, a control and two diets supplemented with an enzyme cocktail premix containing either amylase or xylanase, were each fed to 100 male poults (10 replicates of 10 poults per pen) from 0 to 5 wk of age to observe the effects upon body weight gain, feed intake, and feed efficiency. The amylase-supplemented diet significantly increased feed efficiency through the first 2 wk and significantly increased body weight gain and feed intake through the first 3 wk. Xylanase supplementation did not improve growth or feed efficiency over the control. Mean villus length within the jejunum and ileum was significantly increased at 2 and 3 wk of age by dietary supplementation of amylase when compared with the control and xylanase diets. These findings suggest that the increased growth associated with the amylase diet during 0 to 3 wk can, in part, be explained by the increase in absorptive surface area, allowing for increased digestion of available nutrients coupled with increased enzyme activity for carbohydrate degradation from the supplemental enzymes.

Rotational strength of double-pinning techniques in repair of transverse fractures in femurs of dogs.

Transverse midshaft fractures of femurs from freshly euthanatized dogs were stabilized by means of 6 methods: (1) 3.5-mm bone plate and screws, (2) single intramedullary pin, (3) double intramedullary pins retrograded proximally and driven distally to the level of the femoral trochlea, (4) double intramedullary pins retrograded distally and driven proximally into the trochanteric region, (5) double intramedullary pinning in Rush pin fashion, and (6) multiple intramedullary pinning that filled the medullary cavity at the fracture site. All bones were subjected to torsional stress. The measured strain was converted to forces of torque and correlated with bone diameter to normalize the data. The forces of torque from each fixation technique were compared with each other and with the mean torque force necessary to fracture intact femurs. Torsional shear applied to plated femurs resulted in failure at a mean level of 33.8% of the calculated theoretic moment. Torsional forces were concentrated at one end of the plate and catastrophically failed at that point, whereas the fracture site remained rigidly fixed. There was no significant difference in the initial moment of torsional failure between the single intramedullary pin technique (0.05 Nm) and the double-pinning techniques (0.03 to 0.04 Nm). The multiple-pinning technique was 1.8 to 3 times as effective in resisting rotational forces, compared with the other pinning techniques, but not significantly so.

Improved allograft survival in nonidentical living related donor transplants using donor-specific blood transfusions.

A total of 78 consecutive HLA nonidentical living related donor transplant recipients with moderate to high stimulating mixed lymphocyte culture indexes underwent a deliberate donor-specific blood transfusion protocol. Of the patients 67 were first and 11 were second allograft recipients. Patients were monitored for immunological responses by cytotoxic B-cold, B-warm and T-warm antibody responses to a random panel of 30 donors, and by serial crossmatches to their donor subset B and T lymphocytes at 5C and 37C before beginning the protocol and after each donor-specific blood transfusion. Patients were followed from 3 months to 2 1/2 years, with allograft survival rates reported by the actuarial method. Survival rates of first allograft recipients were 96.0 plus or minus 2.77, 93.97 plus or minus 3.37, 93.97 plus or minus 3.37 and 90.68 plus or minus 4.50 per cent at 3 and 6 months, and 1 and 2 years, respectively. Of the patients entering the protocol for a primary transplant 20.18 per cent had persistently positive crossmatches. With increasing numbers of previous random blood transfusions a statistically significant sensitization rate was noted. Patient sensitization showed a general pattern of initial development of B-warm lymphocytotoxins resulting in positive B-warm crossmatches, which progressed to T-warm lymphocytotoxins and positive T-warm crossmatches if donor-specific blood transfusions continued. However, on development of B-warm positive crossmatches reversion to a negative crossmatch with successful transplantation was possible upon cessation of transfusions. No patient in the study was rendered nontransplantable due to donor-specific blood transfusions. All 5 patients who were completely disparate suffered amnestic type rejection episodes but following control of the rejection the course mimicked that of mixed lymphocyte culture identical living related donor transplants. Donor-specific blood transfusion is highly successful among first allograft recipients and success in extending the procedure to more disparate relatives is noted.

Prospective HLA-DR matching in cadaveric renal transplants: a single center study.

We reviewed 77 potential cadaveric allograft recipients who had undergone prospective HLA-A and B locus and HLA-DR antigen identification. Matching was accomplished, giving first priority to HLA-DR compatibility and relying on HLA-A and B antigen matching only in situations of total HLA-DR incompatibility. Complete HLA-DR identification occurred in 56 per cent of all patients. There were 15 patients (19.5 per cent) who received a 2/2 HLA-DR perfect match, with 86.7 plus or minus 8.8 per cent 1-year actuarial graft survival, and 41 (53 per cent) who received a 1/2 HLA-DR match, with 58.2 plus or minus 7.8 per cent 1-year actual allograft survival. Finally, 21 patients (27 per cent) received a 0/2 HLA-DR match, with 64.9 plus or minus 10.7 per cent actual survival. These results and their mirrored mismatching results showed statistically significant allograft success in only the HLA-DR 2/2 matches. Matching for HLA 2 DR donors proved a statistically significant success over the other HLA-DR allograft matches and the older controversial matching system based on HLA-A and B locus antigens. The restricted gene polymorphism of the HLA-DR systems allows for a relatively high percentage of perfect HLA-DR matches.