Representative dynamic ranges of spinal alignment during gait in patients with mild and severe adult spinal deformities

BACKGROUND CONTEXTSurgical correction strategies for adult spinal deformity (ASD) relies heavily on radiographic alignment goals, however, there is often debate regarding degree of correction and how static alignment translates to physical ability in daily life. Kinematic analysis has the potential to improve the concept of ideal spinal alignment by providing clinically meaningful estimates of dynamic changes in spinal alignment during activities of daily life.PURPOSEEstimate representative dynamic ranges of spinal alignment during gait among ASD patients using 3D motion tracking; compare dynamic alignment between mild and severe deformity patients and to healthy adults.STUDY DESIGN/SETTINGRetrospective review at a single institution.PATIENT SAMPLEFifty-two ASD patients and 46 healthy adults.OUTCOME MEASURESRadiographic alignment, kinematic spine motion, spatiotemporal gait measures, patient reported outcomes (VAS pain, ODI, SRS-22r).METHODSSpinal alignment was assessed radiographically and during standing and overground walking tests. Dynamic alignment was initialized by linking radiographic alignment to kinematic alignment during standing and at initial heel contact during gait. Dynamic changes in maximums and minimums during gait were made relative to initial heel contact for each gait cycle. Total range-of-motion (RoM) was measured for both ASD and healthy subjects. Dynamic alignment measures included coronal and sagittal vertical axes (CVA, SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), and pelvic tilt (PT). ASD patient's deformities were classified as either Mild or Severe based on the SRS-Schwab ASD classification.RESULTSSevere ASD patients had significantly larger dynamic maximum and minimums for SVA, TPA, LL, and PT (all p<.05) compared with Mild ASD patients. ASD patients exhibited little difference in dynamic alignment compared with healthy subjects. Only PT had a significant difference in dynamic RoM compared with healthy (p<.001).CONCLUSIONSMild and Severe ASD patients exhibited similar global dynamic alignment measures during gait and had comparable RoM to healthy subjects except with greater PT and reduced spatiotemporal performance which may be key compensatory mechanisms for dynamic stabilization.     

Older gay men's engagement with physical activity: A scoping review

Older gay men experience an elevated prevalence of adverse health conditions that may be compounded by age-related deterioration. Some of these conditions may be ameliorated by regular adherence to physical activity (PA). However, many gay men participate in less PA than their age-matched heterosexual counterparts. With a focus on gay men aged 60 and over, the aims of this review were to examine the evidence for older gay men's engagement with PA and the research approaches used to describe this group. A systematic search of six academic databases (Academic Search Premier, Cinahl, PubMed, Sport Discus, APA PsychInfo and APA PsychArticles) generated 23 papers from 1970 to 2020 that focused on older gay men's engagement with PA. Although surveys were well represented in the literature, further studies utilising qualitative methodological frameworks have the potential to inform targeted interventional programs aimed at reducing less health disparities. The value of PA in older adults lies principally in improved performance of activities of daily living, independent living, increased longevity, decreased cognitive decline and improved mental well-being.     

Familial Transmission of Alcohol Use Norms and Expectancies and Reported Alcohol Use

Members of 183 families (biological parents and one adult offspring) completed questionnaires on their quantity and frequency of alcohol use, what they would consider a "normal" quantity-frequency of alcohol use, "problem" quantity-frequency of use, flushing after alcohol use, and other expected physiological and subjective responses to alcohol. Within individuals, own quantity-frequency of alcohol use was moderately negatively correlated with flushing after one drink or less ("fast flushing"), but more highly positively correlated with judged normal alcohol use and with expected subjective effects. Spouse resemblances were low for quantity-frequency of alcohol use and flushing, but high for alcohol use norms and expected physiological and subjective responses. Parent-offspring resemblances were low to moderate for own alcohol use and flushing, but moderate to high for expected physiological and subjective effects. These results were discussed in terms of the effects of genetically transmitted flushing after alcohol use and culturally transmitted alcohol norms and expectations on alcohol use.     

GABA(A) receptors mediate inhibition of T cell responses

We describe the presence of functional GABA(A) receptors on T cells. GABA inhibited anti-CD3 and antigen-specific T cell proliferation in vitro in a dose-dependent manner that was 1) mimicked by the GABA(A) receptor agonist muscimol (but not the GABA(B) receptor agonist baclofen), 2) blocked by GABA(A) receptor antagonists and a GABA(A) receptor Cl- channel blocker (picrotoxin) and 3) enhanced by pentobarbital. These data suggest that GABA(A) receptors mediate this immune inhibition and that these receptors can be modulated in a similar fashion to their neuronal counterparts. Finally, GABA inhibited DTH responses in vivo. Thus, pharmacological modulation of GABA(A) receptors may provide new approaches to modulate T cell responses in inflammation and autoimmune disease.     

The trough: peak ratio and the normalization of blood pressure profiles

Experts from the Food and Drug Administration (FDA) of the USA have assumed that hypertensive patients are likely to achieve greatest benefit from therapy in which the antihypertensive effects do not vary excessively during the course of the day. They suggested that the ratio of the minimal (trough) effect to the maximal (peak) effect of the drug should be no lower than 0.5. The concept of the trough: peak ratio (TPR) raises many practical problems. Using actual data, the effect of a drug often shows erratic fluctuations with several local minima and maxima. Mean blood pressure levels for several hours have been used to estimate the trough and peak effects. Blood pressure averages over 4 h may e a good choice, because blood pressures measured 4 h apart are not correlated. The statistical distribution of the TPR is not Gaussian. Negative and very low or positive and very high individual ratios are frequently observed. Therefore, the individual TPR is of questionable clinical value, except when the ratio is applied for responders only. The TPR can be calculated for a sample. In that case, the bootstrap method can be used to estimate the error of the TPR. Most important is the question of why the TPR should be higher than 0.5. We introduced the concept of 'normalization of the blood pressure profile', namely 'reducing the blood pressure profiles in hypertensives to match those profiles in normotensives'. This concept leads very naturally to the TPR and justifies the lower limit of 0.5 for the TPR.     

Cholesterol and other cardiovascular risk factors in a working population in Ile-De-France (France): First results of the PCV-METRA study

In 1989, the French PCV-METRA Group (PCV-METRA = Prévention Cardio-Vasculaire en Médecine du Travail) started a large prospective survey of cardiovascular (CDV) morbidity and mortality and of CVD risk factors, especially cholesterol, in a working population in Ile-de-France, a region including Paris. This report presents the first results of this study, based on a sample of 5758 men and 2603 women, aged 18–65 years. The variables examined included the levels of total cholesterol (TC), High-density-lipooprotein cholesterol (HDL-C), low-density-lipoprotein cholesterol (LDL-C), and the other major CVD risk factors (smoking, sedentary way of life, hypertension, hypercholesterolemia, use of oral contraceptives and familial history of CVD risks). TC and LDL-C significantly increased with age. The changes with age were significantly different in men and women. The levels were similar in both sexes at less than 30 yrs, increased sharply for men after age 30 and were significantly higher in men than in women from 30 to 55 yrs. Beyond 55 yrs, no difference was obserbed between the two sexes. In contrast, HDL-C was higher in women at all age ranges. In the total sample, 35% of men and 21% of women were hypercholesterolemic (TC 2.4 g/ L). Our observations fully confirm and refine previous findings in the US and in other European countries. In addition, a substantial set of data on CVD risk factors for the working population in France, especially for female subjects for whom data are scanty, is now available.Corresponding author.     

Factors involved in the differential response to ethanol,barbital and pentobarbital in rats selectively bred for ethanol sensitivity

Two lines of rats, least affected (LA) and most affected (MA), had been selectively bred for their differential sensitivity to ethanol. Both males and females of the LA strain were observed to be less sensitive than their MA counterparts to the acute hypnotic and motor-impairing effects of ethanol. However, a lower ethanol metabolic rate of the MA males suggests that both CNS and metabolic factors contribute to their enhanced sensitivity to ethanol. By contrast, no differences were observed between the LA and MA males with respect to the hypnotic and subhypnotic effects of pentobarbital or to the clearance of this drug. MA females were more sensitive only to the hypnotic effects of pentobarbital, probably because of a smaller apparent volume of distribution. No strain difference was observed in the hypnotic effect or clearance of barbital. These observations suggest that, in spite of a differential sensitivity to ethanol, the LA and MA lines do not differ in their response to the barbiturates tested.     

Metabolism-based inactivation of neuronal nitric-oxide synthase by components of cigarette and cigarette smoke.

It has been shown that administration of cigarette smoke to rats leads to loss of neuronal nitric-oxide synthase (nNOS) activity and nNOS protein in penile tissue. The exact mechanism for this loss of activity and protein is not known. In the current study, we investigated whether extracts prepared from cigarette smoke or from the cigarette itself could directly inhibit nNOS activity. We discovered that the cigarette smoke extract and the cigarette extract cause a time-, concentration-, and calmodulin-dependent inactivation of nNOS in an in vitro system containing the purified enzyme. L-Arginine, but not D-arginine, protects nNOS from this time-dependent inactivation, suggesting an active site directed event. The kinetics of inactivation are consistent with the metabolism-based or suicide inactivation of nNOS. Based on studies with other metabolism-based inactivators, this cigarette-mediated inactivation may render nNOS more susceptible to proteasomal degradation and thereby may explain the loss of nNOS protein in vivo. The component(s) responsible for nNOS inactivation is not volatile, is not retained by a 3,000 molecular weight cut-off membrane, binds to activated charcoal, and is highly water-soluble under both acidic and basic conditions. The discovery of a direct inactivation of nNOS by an organic, cationic compound(s) present in tobacco and tobacco smoke provides a basis for further study of not only the mechanisms responsible for the biological effects of tobacco but also a search for a potentially novel inactivator of nNOS.     

Implantation of a composite bifurcated cryopreserved aorto-iliac-femoral homograft in a patient with Candida albicans endocarditis

A 35 year old woman, cocaine addict, suffered Candida albicans aortic valve endocarditis complicated with embolisation of infected vegetations in the distal abdominal aorta. She underwent successful staged aortic valve replacement followed by transaortic and transfemoral thrombectomy. One month later an arteriogram disclosed partial occlusion of the left iliac artery, bilateral aneurysmal degeneration of both iliac arteries and right iliac artery-right iliac vein fistula. She was operated again, performing re-laparotomy and re-exploration. A composite bifurcated cryopreserved homograft was implanted end-to-side between the infrarenal abdominal aorta, right external iliac artery and left common femoral artery. The right iliac artery-iliac vein fistula was obliterated with suture. The patient had an uneventful recovery but a relapsing arterio-venous fistula was diagnosed by arteriography. Three months later she underwent percutaneous transluminal closure of the reopened fistula. At present, 17 months after the implantation of the homograft, the patient is symptom-free, on antifungal agents and with arteriographic and clinical evidence of a well-functioning arterial homograft.