Investigating the involvement of the ATF6α pathway of the unfolded protein response in adipogenesis.

The unfolded protein response (UPR) is activated by endoplasmic reticulum stress resulting from an accumulation of unfolded or mis-folded proteins. The UPR is divided into three arms, involving the activation of ATF-6, PERK and IRE-1, that together act to restrict new protein synthesis and increase the production of chaperones. Recent studies have implicated the PERK and IRE-1 components of the UPR in adipocyte differentiation. In this study, we investigate the importance of ATF6α during adipogenesis using stable knockdown of this protein in the model adipogenic cell line, C3H10T1/2. Reduction of ATF6α expression by >70% resulted in impaired expression of key adipogenic genes and reduced lipid accumulation following the induction of adipogenesis. In contrast, loss of ATF6α did not impair the ability of cells to undergo osteogenic differentiation. Overall, our data indicate that all three arms of the UPR, including ATF6α, must be intact to permit adipogenesis to occur.

Use of field-based tests to identify risk factors for injury to fast bowlers in cricket.

OBJECTIVE: To identify risk factors for injury to cricket fast bowlers using field-based tests. DESIGN: Prospective cohort study. SETTING: High performance Australian cricket. PARTICIPANTS: Ninety-one male adolescent and adult fast bowlers (aged 12-33 years). ASSESSMENT OF RISK FACTORS: A field-based pre-participation screening, consisting of musculoskeletal, fitness and anthropometric assessments and analysis of bowling technique was undertaken. Bowlers were prospectively monitored over the 2003-4 season and bowling workload and injuries were recorded. Logistic regression was used to identify injury risk factors. MAIN OUTCOME MEASUREMENT: Repetitive microtrauma injury to the trunk, back or lower limb associated with fast bowling. RESULTS: Two variables were identified as independent predictors of injury in the multivariate logistic regression analysis. Bowlers with hip internal rotation of < or =30 degrees on the leg ipsilateral to the bowling arm were at a significantly reduced risk of injury (OR 0.20, 95% CI 0.06 to 0.73) compared with bowlers with >40 degrees of rotation. Bowlers with an ankle dorsiflexion lunge of 12.1-14.0 cm on the leg contralateral to the bowling arm were at a significantly increased risk (OR 4.03, 95% CI 1.07 to 15.21) than bowlers with a lunge of >14 cm. Bowlers with a lunge of < or =12 cm were also at an increased risk, but not significantly so (OR 1.38, 95% CI 0.40 to 4.84). CONCLUSIONS: Biomechanical research is needed to investigate how these two intrinsic risk factors increase injury risk so that appropriate interventions can be developed.

Is bowling workload a risk factor for injury to Australian junior cricket fast bowlers?

OBJECTIVES: To examine whether bowling workload is a risk factor for overuse injury to Australian junior cricket fast bowlers and to evaluate the appropriateness of current bowling workload guidelines. METHODS: Forty four male fast bowlers (mean (standard deviation) age 14.7 (1.4) years) were monitored prospectively over the 2002-2003 season. Bowlers completed a daily diary to record bowling workloads and self reported injuries, which were validated by a physiotherapist. Bowling workload prior to the first injury (for those bowlers who were injured) was compared to workload across the whole season for uninjured bowlers. RESULTS: Eleven (25%) bowlers reported an overuse-type injury, with seven of these sustaining a back injury. Injured bowlers had been bowling significantly more frequently than uninjured bowlers (median number of days since the previous bowling day: 3.2 v 3.9 days, Mann-Whitney U = 105.0, p = 0.038). Compared with bowlers with an average of > or =3.5 rest days between bowling, bowlers with an average of <3.5 rest days were at a significantly increased risk of injury (risk ratio (RR) = 3.1, 95% confidence interval (CI) 1.1 to 8.9). There were also trends towards an increased risk of injury for those who bowled an average of > or =2.5 days per week (RR = 2.5, 95% CI 0.9 to 7.4) or > or =50 deliveries per day (RR = 2.0, 95% CI 0.7 to 5.4). CONCLUSIONS: This study has identified high bowling workload as a risk factor for overuse injury to junior fast bowlers. Continued research is required to provide scientific evidence for bowling workload guidelines that are age-specific for junior fast bowlers.

Woodsmoke exposure and risk for obstructive airways disease among women.

OBJECTIVE: To investigate if exposure to firewood smoke and other indoor pollutants is a potential risk factor for obstructive airways disease (OAD) among women in Bogota in whom cigarette smoking and other known risk factors may not be the most frequent. DESIGN AND SETTING: We conducted a hospital-based case-control study to identify risk factors for OAD among women in Bogota. An interview was conducted using a modified questionnaire recommended by the American Thoracic Society for epidemiologic studies. PATIENTS: We compared 104 OAD cases with 104 controls matched by hospital and frequency matched by age. ANALYSIS: The odds ratio (OR) was used as the basic statistic to evaluate risk. Multivariate analysis (MA) was conducted by the Mantel-Haenszel procedure and by logistic regression. MAIN RESULTS: Univariate analysis showed that tobacco use (OR = 2.22; p < 0.01), wood use for cooking (OR = 3.43; p < 0.001), passive smoking (OR = 2.05; p = 0.01), and gasoline use for cooking (OR = 0.52; p = 0.02) were associated with OAD. Trends for years of tobacco use and years of wood cooking were present (p < 0.05). After MA, variables remained significant except gasoline use. CONCLUSIONS: This study showed that among elderly women of low socioeconomic status in Bogota, woodsmoke exposure is associated with the development of OAD and may help explain around 50% of all OAD cases. The role of passive smoking remains to be clarified. This work may set the basis for interventional studies in similar settings.

Functional reach improvement in normal older women after Alexander Technique instruction.

BACKGROUND: Functional reach (FR) is a clinical measure of balance. The Alexander Technique (AT) is a nonexercise approach to the improvement of body mechanics. This study investigated a possible relationship between FR performance and AT instruction. METHODS: Three groups comprised of women older than 65, with the exception of one male control, were studied: (i) a pilot group, and (ii) experimental and (iii) control groups. Groups 1 and 2 were given eight 1-hour, biweekly sessions of AT instruction with pre- and posttests in FR, whereas Group 3 was given only pre- and posttests in FR. RESULTS: Groups 1 and 2 both showed significant improvement in FR performance. Group 2 was retested 1 month after posttest and showed a slight decrease in FR performance. For Groups 1 and 2, a questionnaire allowing qualitative responses on a four-item scale showed an overall positive response to the AT instruction. CONCLUSIONS: AT instruction may be effective in improving balance and thereby reducing the incidence of falls in normal older women.

[Factors associated with hospital mortality in patients admitted to the intensive care unit in Colombia]. / Factores asociados con la mortalidad hospitalaria en pacientes admitidos en cuidados intensivos en Colombia.

OBJECTIVES: To describe the demographic features, reasons for hospital admission and factors associated with hospital mortality in patients admitted to intensive care in Colombia. METHOD: A cohort study of patients admitted to intensive care units (ICUs). Of 89 ICUs identified in Colombia, 20 in ten cities were invited to gather information on 200 consecutive patients admitted to each ICU. RESULTS: Three thousand sixty-six patient cases were available for analysis. The mean age was 53 years and 43% were women (men vs. women, p < 0.001). The most frequent cause of admission was medical (63.9%), acute myocardial infarction patients (7.1%) comprising the largest group. Severity of disease measured as APACHE II and III was a mean 14.0 (SD 6.9) and 48.3 (SD 23.5), respectively. Multivariate analysis, independent of adjustment for severity (APACHE II or III), showed that the factors associated with hospital death were the need for mechanical ventilation, pupillary response, transfer from a medical ward, and management by the ICU team prior to admission (p < 0.01). CONCLUSION: The most common reason for admission to an ICU in Colombia was myocardial infarction. Besides severity of disease, other variables related to medical care in Colombia are associated with hospital mortality, such as invasive ventilation. Although these variables may be artifacts related to disease severity, they are more likely to be related to quality of care.

Aircrew soft contact lens wear: a survey of USAF eyecare professionals.

The USAF, when it approved soft contact lens (SCL) wear for aircrew in June 1989, chose a conservative approach that authorizes only daily-wear of extended-wear SCL's. The aircrew SCL program has been perceived as a success, and follow-up data are no longer being collected. A survey was sent to all USAF eyecare professionals to assess the types and extent of SCL-related ocular pathology, the magnitude of environmental SCL problems in the cockpit, and the brands of SCL's that are being fitted. Only two instances of ulcerative keratitis were reported. The most severe inflight problem reported was the dry cockpit environment. CSI-T (Pilkington Barnes-Hind) was the most frequently used spherical lens and the Hydrasoft Toric XW (CoastVision) was the most used toric lens. The USAF aircrew SCL program appears to be progressing successfully. However, the Ophthalmology Branch at Armstrong Laboratory will continue to monitor the program for serious medical complications.

The medical acceptability of soft contact lens wear by USAF tactical aircrews.

Seventy-two Tactical Air Command (TAC) aircrew members completed one full year of soft contact lens (SCL) wear. A daily-wear regimen, using extended-wear lenses, was used to minimize corneal stress. Baseline measurements of visual acuity with SCLs and with spectacles after SCL removal and ocular indicator gradings were compared to measurements at 5-d, 10-d, 1-month, 3-month, 6-month, and 12-month examinations. Visual acuity did not decrease during the test. No aircrew member developed corneal ulcers or other serious complications requiring elimination from the test. Two aircrew members lost a total of 9 "duties not to include flying" (DNIF) days: one flyer was grounded for 1 d with a corneal abrasion and another for 8 d with epithelial microcysts. The TAC SCL Test, as designed, was generally successful. The conservative approach to SCL wear during the test and the meticulous follow-up care by United States Air Force eye care professionals most likely contributed to the low ocular complication rate.

The durability of hydrogel extended-wear contact lenses worn for daily wear by USAF aircrew members.

Hydrogel extended-wear contact lenses, worn on a daily-wear regimen, were tested for 1 year by USAF aircrew members. A total of 62 eyes were fitted with Hydrocurve II (55% water content) spherical lenses, 29 with Hydrocurve II (55% water content) toric lenses, and 61 with CSI-T (38.5% water content) spherical lenses. The mean lens replacement rate for torn lenses per aircrew member was determined to be 1.45 lenses a year. The replacement rate of Hydrocurve II spherical lenses compared to CSI-T lenses was not statistically significant. However, the replacement rate for Hydrocurve II toric lenses was significantly lower than both Hydrocurve II spherical lenses and CSI-T lenses (p less than 0.01). The extended-wear lenses tested in this study appeared to be durable enough for the rigors of daily wear.

Rigid gas-permeable contact lens wear during + Gz acceleration.

This study was designed to determine how well rigid gas-permeable contact lenses maintain position on the cornea under high G forces, and the effect on visual acuity. One hyperopic and five myopic subjects were fitted with lenses made from Pasifocon C material (specific gravity = 1.07). Two lens diameters (8.8-9.4 mm and 9.6-10.0 mm) were compared upon the myopic subjects for centering on the cornea. Visual acuity was measured at + 1 Gz (baseline), +3 Gz, +4 Gz, +6 Gz, and +8 Gz in the straight-ahead, lateral, and up-gaze positions from three acuity charts mounted in the gondola. All lenses, as estimated from the videotape, decentered down the z axis 2-3 mm at high + Gz. Visual acuity was reduced at the higher +Gz levels to similar measurements in most subjects for both the contact lens and spectacle control rides. No lens displaced from the cornea or dislodged from the eye during any of the 25 centrifuge runs.

Contact lens wear with the USAF Protective Integrated Hood/Mask chemical defense ensemble.

The Protective Integrated Hood/Mask (PIHM) chemical defense aircrew ensemble blows air from the mask's plenum across the visor at a rate of approximately 15 L/min in order to prevent fogging of the visor and to cool the aircrew member's face. This study was designed to determine the effect of the PIHM airflow on soft contact lens (SCL) dehydration, contact lens comfort, and corneal integrity. There were 26 subjects who participated in this study: 15 SCL wearers, 6 rigid gas-permeable (RGP) wearers, and 5 nonspectacle wearing controls. Contrast acuity with the 3 Regan charts, subjective comfort, and relative humidity (RH) and temperature readings under the PIHM mask were monitored every 0.5 h during 6-h laboratory rides. Slit-lamp examinations and SCL water content measurements with a hand-held Abbe refractometer were made before and after the rides. High RH under the mask may have accounted for the moderate SCL dehydration (8.3%), no decrease in contrast acuity for any group, and lack of corneal stress. Although all groups experienced some inferior, epithelial, punctate keratopathy, RGP wearers had the most significant. SCLs performed relatively well in the PIHM mask environment. Testing with other parameter designs is necessary before recommending RGPs with the PIHM system.

The USAF Aircrew Medical Contact Lens Study Group: operational problems.

BACKGROUND: Although soft contact lens (SCL) wear for aircrew with refractive errors was approved in June 1989, aircrew with certain ocular disorders, such as keratoconus, have been waivered to fly with contact lenses (CL) since the 1960's. These aircrew are members of the United States Air Force (USAF) Medical Contact Lens Study Group and are fitted [with SCL's or hard contact lenses (HCL)] and followed by the Ophthalmology Branch at Armstrong Laboratory; Brooks Air Force Base, TX. Because HCL's are perceived to be more susceptible to a disabling foreign body (FB) under a lens and are more difficult to remove in flight, Study Group aircrew are the only USAF HCL wearers allowed to fly. METHODS: The medical records of the 142 aircrew members followed for CL wear between 1970 and 1993 were retrospectively examined to determine the type of CL worn, crew position, and the medical reason for CL wear. The Study Group was then surveyed to ascertain whether there were any significant operational problems for aircrew wearing medically indicated CL's. Aircrew were divided into HCL (51 surveys returned) and SCL (44 surveys returned) wearers to compare each modality's efficacy in the flight environment. RESULTS: HCL wearers were more likely than SCL wearers to have endured at least one FB incursion under a lens during flight (p = 0.053). HCL wearers were also more likely to have had a lens come off-center at least once in their careers during flight (p = 0.035). Both groups reported problems with CL dryness in the 5-15% relative humidity of the cockpit. Only four aircrew reported any CL-related Duties Not Involving Flying (DNIF) days during their careers. CONCLUSION: Because HCL's are necessary to correct vision adequately to return aircrew with keratoconus and other corneal anomalies to the cockpit, the USAF needs to continue to investigate the use of rigid gas-permeable HCL's with aircrew.

A comparison of stereopsis with ANVIS and F4949 night vision goggles.

BACKGROUND: This study was undertaken to see if the model of NVG affects stereoacuity. METHODS: We tested 13 male and 2 female aircrew with the Aviator's Night Vision Imaging System (ANVIS) and F4949 NVGs. Visual acuity was measured using the NVG Resolution Grid and stereopsis was determined using a modified Howard-Dolman test. RESULTS: In simulated light conditions, average stereoscopic threshold using the F4949 NVG (17.35 arc s) was not significantly better than the ANVIS NVG (18.42 arc s), the mean difference being 1.07 arc s (95% confidence limits, -2.85 to 4.99). CONCLUSIONS: The Howard-Dolman test proved to be effective in eliminating monocular clues, thus validating its use in testing NVG stereopsis. The distribution of visual acuities across subjects and goggle models was too narrow to evaluate the effect of visual acuity on stereoacuity in NVGs. Differences in trial means during the course of the study indicated the presence of a "learning" effect on the Howard-Dolman test.

The role of optometry in the USAF vision research program.

BACKGROUND AND METHODS: Optometry has played a significant role in the USAF vision research program since the early 1960s. The Air Force Institute of Technology (AFIT) sponsors active duty optometry officers for Ph.D. and masters programs in Physiological Optics at civilian universities. After training, they are assigned to research laboratories at Brooks AFB, TX, or Wright-Patterson AFB, OH. Senior research optometrists manage vision and medical research programs and have served on the staff of the United States Air Force (USAF) Surgeon General. RESULTS AND CONCLUSIONS: Research papers reporting on USAF vision research programs, especially those germane to improving aircrew combat effectiveness, have been published extensively by USAF optometrists in Air Force and joint services technical reports as well as the open literature. These programs include: refractive error trends, contact lenses, ophthalmic materials, night vision, aircraft transparency measurement, nuclear flashblindness, laser, and space flight. As long as vision remains the most important sensory input to the pilot, USAF optometrists will remain an integral part of the aerospace medical research team.

Ethical challenges in pharmacoepidemiological research in Colombia.

PURPOSE: To illustrate and to discuss some ethical challenges encountered during pharmacoepidemiological research in a developing country (Colombia), as well as the decisions made to solve them. METHODS: The authors in Bogotá describe three recent studies. The first one collected data from clinical records to evaluate the prescriptions patterns in recently graduated physicians. The second used an interrupted time series design, with a set of observations prior and after a combined intervention, to assess whether it improved the quality of intravenous antibiotic prescribing practices in a university-based hospital. The third evaluated pharmacists' advice in childhood acute respiratory infection and acute diarrhea through a community survey, followed by focus groups and in-depth interviews of key informers. RESULTS: The ethical issues raised by these studies include the need for obtaining informed consent from participants (physicians in Study 1 and drug sellers in Study 3), deciding when to intervene in case of gross prescription mistakes detected during the collection of data as part of the time series assessment (Study 2), the use of simulated clients to collect data in the community survey, and the use of study resources to buy, in some cases, useless medications (Study 3). CONCLUSION: Although ethical challenges in pharmacoepidemiology in non-industrialized countries like Colombia may be different from those in developed nations, ethical principles that guide research remain the same. The processes to safeguard these principles in Colombia for virtually all research are also universal in nature, and include the ethical review committee, subject privacy, informed consent, and disclosure of funding sources.

Potassium requirement of dairy cows in early and midlactation.

Two trials with lactating Holstein cows were to determine the percent potassium required in the ration. A midlactation study compared three potassium percentages (.46, .69, and .97% of dry matter) for five cows assigned to each treatment for a 10-wk experimental period. In an early lactation study, 15 cows were assigned at 2 wk postpartum to one of three treatments (.51, .75, and .99%) for an 8-wk experimental period. Feed intake was changed by treatment from a control period (all cows fed the high K ration) +1.3, -.3, and +.1 kg for the .46, .69, and .97 treatments and +3.4, +1.0, and +.5 kg for the .51, .75, and .99 treatments. Milk production and change in body weight differed significantly in the first trial but not in the second trial. Blood serum potassium was significantly different due to treatment in the second trial with changes in percent potassium of -.6, -.4 and +1.1 for the three treatments. A potassium content of .7% appears to be adequate for cows in mid to late lactation; however, the feed intake and potassium in serum indicate that .7% may not be optimal for high producing cows in early lactation.

Risk factors for multiorgan failure: a case-control study.

The aim of this study was to identify factors associated with Multiple Organ Failure (MOF), and assess possible interactions between the risk factors identified as such. We studied 40 MOF cases and 120 controls, out of all the surgery and trauma patients who needed intensive care at our institution in a 24-month period. The univariate analyses showed that age, hypovolemic shock, massive volume administration (MVA), sepsis, and time of evolution before arriving to the hospital (TE) were significantly associated with MOF. Logistic regression analysis showed that neither age nor MVA were independently associated with MOF after adjusting for all of the other variables. Interactions seemed to be present between age, sepsis, and shock. We conclude that in our surgery and trauma ICU adult patient population, hypovolemic shock, sepsis, and TE are independent risk factors for MOF. The importance of the association between shock and sepsis is discussed, as well as the possible relevance of TE as a risk factor.

Effect of dietary potassium percent for lactating dairy cows.

Three groups of Holstein cows (four cows per group) past the peak of lactation were fed dietary potassium as percent of dry matter as follows: .45% for 20 days to all groups; .45, .55, and .66% to the respective groups for 12 wk; and .66% to all groups for 19 days. Dietary potassium had no significant effect on milk fat and solids-not-fat contents of milk, milk production, or milk and blood serum cations (potassium, sodium, magnesium, calcium). However, body weights were affected. Symptoms common in potassium deficiency were not apparent. Average daily milk production, feed intake, and body weight gains for the 12 wk in kilograms were: 21.9, 15.8, and 15.7; 23.4, 16.4, and 54.5; and 22.8, 19.9, and 92.9 for the .45, .55, and .66% rations. When .66% potassium was fed to groups previously fed .45 and .55% potassium, feed intake increased by 3.6 kg and 1.3 kg but increased only .2 kg in the group previously fed .66%.