Changes in gastro-intestinal function in humans at an altitude of 3,500 m

Summary The gastric juice secretion, acid concentration and peptic activity were studied before and after pentagastrin stimulation in 10 sea level residents, first at sea level and then during 22 days sojourn at 3,500 m and in two other groups of 10 men, one of which consisted of natives of high altitude and the other of lowlanders acclimatized to high altitude. In addition, measurements of xylose excretion, energy, fat and protein utilization, along with fluid balance were made on sea level residents, referred to as sojourners, both at sea level and high altitude.The basal and maximal gastric juice volumes of the three groups at high altitude did not differ significantly. The maximal rate of acid production was lower in high altitude natives as compared to the other two groups. Peptic activity was higher in sojourners at high altitude, whereas it did not show any difference in acclimatised low landers as compared to sea level values of sojourners. There was no significant difference in D-xylose excretion in sojourners at high altitude. The food intake of sojourners was reduced at high altitude without any change in the efficiency of food utilization. There was no change in fluid balance.     

Report of the Ad Hoc Committee on Risk Factors for Coronary Artery Bypass Surgery

The Society of Thoracic Surgeons remains greatly concerned about the use of raw mortality data as the sole measure to determine quality of care following coronary artery bypass surgery. Use of such data without consideration of risk factors that are predictors of hospital mortality and of other indices of quality of care is inappropriate and misleading and may adversely affect the care of the high-risk cardiac surgical patient. The Society is committed to the principle of providing the public with accurate information regarding the conduct of coronary artery surgery. However, it believes that the data provided by HCFA do not provide this information and should not be used as the sole index of quality of care following coronary artery bypass surgery.     

Post‐Traumatic Heterotopic Ossification: An Old Problem in Need of New Solutions

Heterotopic ossification (HO) is the formation of pathological bone in ectopic sites and it can have serious consequences for functional outcomes. For many years, its main clinical relevance was as a rare complication of elective joint arthroplasty or CNS injury and a number of prophylaxes were developed to mitigate against it in these settings. As a consequence of changes in patterns of wounding and survival in conflicts since the turn of the century, post‐traumatic HO has become much more common and case severity has increased. It represents one of the main barriers to rehabilitation in a large cohort of combat‐injured patients. However, extant prophylaxes have not been shown to be effective or appropriate in this patient cohort. In addition, the lack of reliable early detection or means of predicting which patients will develop HO is another barrier to effective prevention. This review examines the current state of understanding of post‐traumatic HO including the historical context, epidemiology, pathophysiology, clinical issues, currently prophylaxis and detection, management, and potential future approaches. Our aims are to highlight the current lack of effective means of early detection and prevention of HO after major trauma and to stimulate research into novel solutions to this challenging problem. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1061–1068, 2018.     

Determination of genetic damage and urinary metabolites in fuel filling station attendants

Fuel (diesel and petrol) constitutes a complex mixture of volatile flammable liquid hydrocarbons among them benzene (BZ), toluene (TOL), and xylene (XYL) are considered to be the most hazardous, predominantly BZ because of its carcinogenic potency. Exposure to these compounds may have an impact on the health of the exposed subjects. Hence, genotoxicity and quantitative analysis of these compounds was performed in blood and urine samples of 200 workers exposed to fuel in filling stations and compared to controls. The level of genetic damage was determined by micronucleus test (MNT) in buccal epithelial cells (BEC) and chromosomal aberrations (CA) assay in peripheral blood lymphocytes (PBL) of fuel filling station attendants (FFSA) and compared to a matched control group. Urine analysis for BZ and its metabolites, phenol (Ph), trans, trans‐Muconic Acid (t, t‐MA), and S‐Phenyl Mercapturic Acid (S‐PMA) was done in all the study subjects. The results of our study revealed that exposure to BTX in petrol vapors induced a statistically significant increase in the frequency of micronuclei (MN) and CA in the exposed subjects than in controls (P < 0.05). There was a significant rise in the levels of urinary BZ, Ph, t, t‐MA, and S‐PMA in the exposed subjects. Our study highlights the significance of MNT, CA, and urinary metabolites as potential biological exposure indices of genetic damage in FFSA. This study suggests the need for regular monitoring of FFSA for possible exposure to BTX as a precautionary and preventive step to minimize exposure and reduce the associated health risks. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.     

Venlafaxine treatment stimulates expression of brain-derived neurotrophic factor protein in frontal cortex and inhibits long-term potentiation in hippocampus

Antidepressant action may involve stimulation of brain-derived neurotrophic factor (BDNF). BDNF also regulates long-term potentiation (LTP). We hypothesized that the 5-HT and norepinephrine reuptake inhibitor, venlafaxine, would stimulate BDNF expression and alter LTP more effectively than the selective 5-HT reuptake inhibitor, citalopram. To test this, we administered venlafaxine or citalopram to rats for 1 or 3 weeks; control rats received vehicle only. We measured BDNF protein in hippocampal and frontal cortex homogenates, and serum. We assessed LTP in area cornu ammonis region 1 (CA1) of in vitro hippocampal brain slices. We also examined input/output function to determine if basal synaptic transmission in area CA1 was altered. Compared to vehicle control, frontal cortex BDNF protein was significantly greater after three, but not one, weeks of venlafaxine treatment. In contrast, citalopram (1 or 3 weeks) did not stimulate BDNF. The stimulatory effect of venlafaxine treatment on BDNF was superimposed on a general time-dependent decrease in expression which was seen in both vehicle control and citalopram-treated animals. LTP was significantly impaired in slices from venlafaxine-treated rats after both 1 and 3 weeks of treatment, but LTP appeared normal in slices from citalopram-treated and vehicle control rats. The LTP impairment caused by venlafaxine treatment was independent of changes in BDNF: LTP was impaired after only 1 week of treatment, prior to any effect on BDNF, and LTP magnitude was not correlated with BDNF protein concentration. Input/output function was significantly but equally reduced after 3 weeks of citalopram, venlafaxine, or control treatment. Decreased BDNF protein in citalopram and vehicle control animals, and decreased input/output function may be consequences of individual housing of animals, which we used to ensure proper dosing. Venlafaxine stimulation of BDNF and inhibition of LTP may be related to the reported effectiveness of venlafaxine in treatment of depression.     

Reverse LISS plating for intertrochanteric Hip Fractures in elderly patients

Background  

Fractures of the intertrochanteric hip are common and the treatment of unstable fractures generally requires an operative approach. In elderly patients, osteoporosis makes internal fixation problematic and frequently contributes to failed fixation and poor clinical results. We have attempted to apply the Less Invasive Stabilization System (LISS) in reverse position for the repair of intertrochanteric hip fractures in elderly patients with osteoporotic bones. A retrospective review is presented of the cases of 28 elderly patients with stable and unstable fractures of the intertrochanteric hip treated using the reverse LISS.     

Survey of Geriatricians on the Effect of Fecal Incontinence on Nursing Home Referral

OBJECTIVES: Determine the effect of fecal incontinence (FI) on healthcare providers' decisions to refer patients for nursing home (NH) placement. DESIGN: Survey. SETTING: Questionnaires were e‐mailed to participants' homes or offices. Participants could also volunteer at the 2008 American Geriatric Society annual meeting in Washington, DC. PARTICIPANTS: Two thousand randomly selected physician members and all 181 nurse practitioner members of the American Geriatrics Society were surveyed. MEASUREMENTS: The survey presented a clinical scenario of a 70‐year‐old woman ready for discharge from a hospital and asked about the likelihood of making a NH referral if the patient had no incontinence, urinary incontinence (UI) alone, or FI. Subsequent questions modified the clinical situation to include other conditions that might affect the decision to refer. A second survey of respondents to Survey 1 addressed possible moderators of the decision to refer (e.g., family caregiver presence, diarrhea or constipation, other physical or psychiatric limitations). Significance of differences in the relative risk (RR) for NH referral was tested using the chi‐square test. RESULTS: Seven hundred sixteen members (24.7% response rate) completed the first survey, and 686 of the 716 (96%) completed the second. FI increased the likelihood of NH referral (RR=4.71, P<.001) more than UI did (RR=1.90, P<.001). Mobility restrictions, cognitive decline, and multiple chronic illnesses increased the likelihood of NH referral more than FI alone (P<.001 for each), but in all scenarios, adding FI further increased the likelihood of referral (P<.001). Having family caregivers willing to help with toileting attenuated the likelihood of referral. CONCLUSION: FI increases the probability that geriatricians will refer to a NH. More‐aggressive outpatient treatment of FI might delay or prevent NH referral, improve quality of life, and reduce healthcare costs.     

Attributing Hardy-Weinberg Disequilibrium to Population Stratification and Genetic Association in Case-Control Studies

Loci exhibiting Hardy-Weinberg disequilibrium (HWD) are often excluded from association studies, because HWD may indicate genotyping error, population stratification or selection bias. For case-control studies, HWD can result from a genetic effect at the locus. We extend the modelling to accommodate both stratification and genetic effects. Theoretical genotype frequencies and HWD coefficients are derived under a general genetic model for a population with two strata. Maximum likelihood is used to estimate model parameters and a test for lack of fit identifies the models most consistent with the data. Simulations were used to assess the method.
The technique was applied to a group of ethnically and clinically heterogeneous kidney stone formers and controls, both exhibiting HWD for the R990G SNP of the CASR gene. Results indicate the best fitting model incorporates both stratification and genetic association. The ability of our method to apportion HWD to stratification and genetic effects may well be a significant advance in dealing with heterogeneity in case-control genetic association studies.