Measure Of Reserve Research Articles

Algorithm for Complementary and Alternative Medicine Practice and Research in Type 2 Diabetes

To develop a model to direct the prescription of nutritional and botanical medicines in the treatment of type 2 diabetes for both clinical and research purposes. Available literature on nutritional and botanical medicines was reviewed and categorized as follows: antioxidant/anti-inflammatory; insulin sensitizer; and beta-cell protectant/insulin secretagogue. Literature describing laboratory assessment for glycemic control, insulin resistance, and beta-cell reserve was also reviewed and a clinical decision tree was developed. Clinical algorithms were created to guide the use of nutritional and botanic medicines using validated laboratory measures of glycemic control, insulin sensitivity, and beta-cell reserve. Nutrient and botanic medicines with clinical trial research support include coenzyme Q10, carnitine, alpha-lipoic acid, N-acetylcysteine, vitamin D, vitamin C, vitamin E, chromium, vanadium, omega-3 fatty acids, cinnamon (Cinnamomum cassia), fenugreek (Trigonella foenum-graecum), and gymnema (Gymnema sylvestre). Clinical algorithms can direct supplementation in clinical practice and provide research models for clinical investigation. Algorithms also provide a framework for integration of future evidence as it becomes available. Research funding to investigate potentially beneficial practices in complementary medicine is critically important for optimal patient care and safety.

Induction of TRPC6 Channel in Acquired Forms of Proteinuric Kidney Disease

Injury to podocytes and their slit diaphragms typically leads to marked proteinuria. Mutations in the TRPC6 gene that codes for a slit diaphragm-associated, cation-permeable ion channel have been shown recently to co-segregate with hereditary forms of progressive kidney failure. Herein is shown that induced expression of wild-type TRPC6 is a common feature of human proteinuric kidney diseases, with highest induction observed in membranous nephropathy. Cultured podocytes that are exposed to complement upregulate TRPC6 protein. Stimulation of receptor-operated channels in puromycin aminonucleoside-treated podocytes leads to increased calcium influx in a time- and dosage-dependent manner. Mechanistically, it is shown that TRPC6 is functionally connected to the podocyte actin cytoskeleton, which is rearranged upon overexpression of TRPC6. Transient in vivo gene delivery of TRPC6 into mice leads to expression of TRPC6 protein at the slit diaphragm and causes proteinuria. These studies suggest the involvement of TRPC6 in the pathology of nongenetic forms of proteinuric disease.

Evaluation of the utility of multiple endocrine and ultrasound measures of ovarian reserve in the prediction of cycle cancellation in a high-risk IVF population

Unexpectedly poor response leading to IVF cycle cancellation is a distressing treatment outcome. We have prospectively assessed several markers of ovarian reserve in a high risk IVF population to determine their utility in predicting IVF cycle cancellation. Eighty-four women at high risk of cycle cancellation due to raised FSH, previous poor response and/or age > or =40 years attending for high-dose short protocol IVF treatment had baseline measures of FSH, inhibin B, anti-Müllerian hormone (AMH), antral follicle count (AFC) and ovarian volume. A GnRH agonist was then administered and, 24 h later, estradiol (E(2)) and inhibin B measures were repeated. Fifty-seven per cent of patients in this study had a poor response to stimulation, and 15% were cancelled. Using multivariate logistic regression, we found that day 3 inhibin B levels were the best predictor of cycle cancellation with an area under the receiver operating curve (ROC AUC) = 0.78 (P = 0.017). When only considering baseline variables, mean ovarian volume was the best predictor of cycle cancellation (ROC AUC = 0.78; P = 0.016). AMH concentrations were the best predictor of a poor response (P = 0.003), and AMH was also predictive of cycle cancellation (P = 0.007) with very little inter-cycle variability. None of the parameters studied were predictive of ongoing pregnancy. This group of at-risk patients had a high rate of poor response to simulation and cancellation. Although several measures of ovarian reserve were able to predict cycle cancellation, none were able to predict pregnancy. AMH was predictive of both cycle cancellation and poor response with little inter-cycle variability.

The Brain Reserve Hypothesis, Brain Atrophy and Aging

Background: Researchers have used the concept of brain reserve to explain the dissociation between pathological brain damage and cognitive and functional performance. A variety of brain reserve hypotheses exist, and different empirical strategies have been employed to investigate these variants. Objective: The study investigates (i) the relationship between measures of brain burden (atrophy, white matter hyperintensities (WMH)) and measures of reserve (education, creativity, and intelligence); (ii) the relationship between cognitive decline and reserve; (iii) whether measures of reserve mediate the effect of atrophy on estimated cognitive change, and (iv) the association between brain risk factors, education and atrophy. Methods: A cross-sectional study of a sample of 446 individuals 60–64 years of age who underwent MRI scans as part of a large epidemiological study. Measures were taken of education, intelligence, creativity, cognitive speed, brain volume, WMH, estimated cognitive decline from earlier in life and brain atrophy. Results: No association was found between estimated cognitive decline and brain burden (atrophy, WMH). Risk factors for brain insult were not associated with greater brain atrophy in the less well educated. Neither education, nor any other measure including intelligence or creativity, provided a buffer for cognitive decline in individuals with high levels of brain atrophy. Conclusion: Little support was found for the brain reserve hypothesis.

Mineralogical budgeting of potassium in soil: A basis for understanding standard measures of reserve potassium

AbstractThe study was conducted to investigate the relationship between some standard measures of soil reserve potassium (K) and soil mineralogy. Eight different agricultural soils from the N temperate and S boreal regions were studied and analyzed both by standard methods (exchangeable K, 2 M HCl‐ and aqua regia–extractable K) and by quantitative mineralogical methods based on X‐ray powder diffraction analysis of spray‐dried bulk soils. Linear regression and multivariate methods were used to assess the relationships between standard measures of soil reserve K and a number of soil chemical, physical, and mineralogical properties. A mineralogical budgeting approach, to estimate total K and its speciation between different mineral phases, is shown to be accurate after validation against total K analyzed geochemically. This approach enabled us to determine that both HCl‐ and aqua regia–extractable K were highly correlated with K in dioctahedral phyllosilicates and extracted 1%–17% and 5%–45% of total K, respectively. Neither extraction showed any obvious relationship to K in feldspar, which is frequently a larger reservoir of K in the soils examined.

Autologous transplantation in elderly patients with multiple myeloma: are we asking the right questions?

Multiple myeloma is a disease of the elderly. Survival outcomes remain unacceptably low in older adults with multiple myeloma. To date, no obvious difference in tumor biology has been elucidated to explain the survival disparity between older and younger patients. Multiple factors including comorbidity, performance status, decreased physiologic reserve and potentially undertreatment contribute to poor outcomes in elderly patients with multiple myeloma. High-dose chemotherapy with autologous stem cell transplantation (ASCT) is increasingly being used to treat elderly patients with multiple myeloma in an effort to improve survival outcomes. Recent case comparison studies, and preliminary transplant registry data suggest that selected older patients can be treated with high-dose chemotherapy effectively with similar toxicity and survival benefits compared to younger patients. Traditional upper age limits for autologous transplantation are being challenged along with the definition of 'elderly' itself. Ultimately, the role of high-dose chemotherapy with stem cell rescue in the upfront treatment of older adults with multiple myeloma can only be established by prospective randomized trials. In the process of designing studies to investigate the use of ASCT in older patients, multiple issues unique to the elderly population will need to be considered. First, it will be critical to develop and validate patient selection algorithms that incorporate measures of comorbidity, cognitive function, physiologic reserve and psychosocial function to identify patients most likely to tolerate and benefit from ASCT. Second, preparative and conditioning regimens will need to be further tailored to maximize the benefit to risk ratio. Finally, outcome measures in clinical trials should include disability and quality of life measures, which may be equally important in making treatment decisions for older patients. The future application and study of autologous transplantation in older patients with multiple myeloma provides a unique opportunity to challenge ageism and serve as a model for development of tailored assessments and interventions in this population.

Assessment of Adrenal Reserve in Pregnancy: Defining the Normal Response to the Adrenocorticotropin Stimulation Test

Normal pregnancy is a state of hypercortisolism, making adrenal insufficiency difficult to diagnose. We sought to identify a normative, minimum-response threshold for the ACTH stimulation test in pregnancy. We hypothesized that salivary free cortisol (SaFC) would prove a more physiological and less variable measure of adrenal reserve in pregnancy than serum cortisol (SC). This is a prospective study of normal controls. The study was conducted in an obstetrical clinic in a tertiary care hospital. Patients included 36 healthy ambulatory pregnant women (aged 18-37 yr) with singleton pregnancies. The 250-microg ACTH stimulation test was performed in the healthy pregnant volunteers. Based on their gestational age at the time of recruitment, women were studied in one of the trimesters and were restudied at 11-14 wk postpartum. Total SC, aldosterone, and SaFC concentrations were measured before and after ACTH. The response in pregnancy was compared with postpartum values. Basal SC (P = 0.01), aldosterone (P = 0.001), and SaFC (P = 0.01) values progressively increased during the trimesters of pregnancy and decreased postpartum, confirming that pregnant women have increased basal glucocorticoid and mineralocorticoid production. There was enhanced responsiveness of the maternal adrenal glands to ACTH stimulation as pregnancy progressed, as measured by peak stimulated SaFC (P = 0.009) and aldosterone (P = 0.01). In the milieu of altered binding globulins, SaFC is a more consistent, binding-globulin-independent measure of stimulated adrenal function than total SC. Minimum criteria for the normal SaFC response to ACTH stimulation in the second and third trimesters of pregnancy and postpartum have been generated based on a predominantly African-American group of subjects. Reliable data are available for the evaluation of the adrenal axis in pregnancy with a noninvasive, outpatient measure of SaFC. Glucocorticoid therapy in pregnancy should take into account that adrenal reserve increases as pregnancy progresses.

Reduced Heart Rate Variability: An Indicator of Cardiac Uncoupling and Diminished Physiologic Reserve in 1,425 Trauma Patients

Measurements of a patient's physiologic reserve (age, injury severity, admission lactic acidosis, transfusion requirements, and coagulopathy) reflect robustness of response to surgical insult. We have previously shown that cardiac uncoupling (reduced heart rate variability, HRV) in the first 24 hours after injury correlates with mortality and autonomic nervous system failure. We hypothesized: Deteriorating physiologic reserve correlates with reduced HRV and cardiac uncoupling. There were 1,425 trauma ICU patients that satisfied the inclusion criteria. Differences in mortality across categorical measurements of the domains of physiologic reserve were assessed using the chi test. The relationship of cardiac uncoupling and physiologic reserve was examined using multivariate logistic regression models for various levels of cardiac uncoupling (>0 through 28% reduced HRV in the first 24 hours). Of these, 797 (55.9%) patients exhibited cardiac uncoupling. Deteriorating measures of physiologic reserve reflected increased risk of death. Measures of acidosis (admission lactate, time to lactate normalization, and lactate deterioration over the first 24 hours), coagulopathy, age, and injury severity contributed significantly to the risk of cardiac uncoupling (area under receiver operator curve, ROC=0.73). The association between deteriorating reserve and cardiac uncoupling increases with the threshold for uncoupling (ROC=0.78). Reduced heart rate variability is a new biomarker reflecting the loss of command and control of the heart (cardiac uncoupling). Risk of cardiac uncoupling increases significantly as a patient's physiologic reserve deteriorates and physiologic exhaustion approaches. Cardiac uncoupling provides a noninvasive, overall measure of a patient's clinical trajectory over the first 24 hours of ICU stay.

Cognitive Reserve and the Relationship Between Depressive Symptoms and Awareness of Deficits in Dementia

Cognitive Reserve and the Relationship Between Depressive Symptoms and Awareness of Deficits in Dementia

Cognitive Reserve and the Relationship Between Depressive Symptoms and Awareness of Deficits in Dementia

Depression and low cognitive reserve are linked to impaired awareness in dementia, although their relative contributions are unknown. The authors investigated the impact of depressive symptoms and cognitive reserve on awareness in questionable and mild dementia. Sixty-six patients completed measures of cognitive reserve, awareness, and depressive symptoms. Cognitive reserve and its interaction with depressive symptoms accounted for significant proportions of variance in awareness; depressive symptoms alone did not. Depressive symptoms and awareness were positively related in high, but not low, cognitive reserve groups. Findings suggest cognitive reserve moderates the depression/awareness relationship in dementia, which may explain previously discrepant findings.

Reproduction and ovarian ageing

Female fertility rates are inherently linked to a woman's age, which is in turn related to ovarian function. Reproductive potential declines gradually until 37-38 years of age, from when the rate of decline hastens. Approximately 1% of women suffer from premature ovarian ageing, and many may not have completed their families. This paper reviews the physiology and fertility consequences of ovarian ageing, premature ovarian failure, measures of ovarian reserve and methods of fertility preservation.

Reproductive ageing and ovarian function: is the early follicular phase FSH rise necessary to maintain adequate secretory function in older ovulatory women?

Serum FSH elevations and decreases in inhibin B have been consistently demonstrated in the early follicular phase of cycles in women of advanced reproductive age. However, secretory products of the dominant follicle (estradiol and inhibin A) in the serum of older ovulatory women are maintained at levels similar to those of their younger counterparts. The goal of this investigation was to determine if ovarian secretory capacity is dependent on relative FSH levels and if basal measures of ovarian reserve reflect ovarian secretory capacity. We administered equivalent low, but effective doses of recombinant FSH for 5 days to a group of older subjects (40-45 years, n=9) and younger controls (20-25 years, n=10) after pituitary suppression with a GnRH agonist. Outcome measures included follicular development as determined by serial transvaginal ultrasound examinations and serum levels of estradiol, inhibin A and inhibin B. Serum levels of estradiol and inhibin A were not statistically different between the two groups, while the number of large follicles formed was greater in the younger subjects. Basal parameters of ovarian reserve were not significantly correlated with ovarian secretory capacity, but did correlate with the number of follicles recruited in response to low-dose FSH. By providing equivalent serum levels of FSH in older and younger reproductive aged women, this study demonstrates that the secretory capacity of recruited follicles is maintained in older reproductive aged women.

Estimating Capacity Utilization from Survey Data

In this paper, we review the history and concepts behind the Federal Reserve's measures of capacity and capacity utilization, summarize the methods used to construct the measures, and describe the principal source data for these measures - the Census Bureau's Survey of Plant Capacity. We show that the aggregate manufacturing utilization rate from the Survey of Plant Capacity does not exhibit the cyclical bias possessed by utilization rates from the less statistically rigorous utilization rate surveys previously used to estimate the Federal Reserve's measures. At the detailed industry level, utilization rates from the Survey of Plant Capacity for several industries do appear to possess a cyclical bias, but we demonstrate that this bias is removed in the construction of the Federal Reserve capacity measures. We further show that the Federal Reserve measures, by combining the Census survey utilization rates with other indicators of capacity, do not discard significant information contained in the Census rates. In fact, the Federal Reserve procedures add to the predictive content of the Census utilization rates in models of capital spending, capacity expansion, and changes in price inflation.

A comparison of oxygen uptake efficiency slope in normal and implant cardiac resynchronization therapy subjects

Introduction: In this study we aimed to determine the validity and usefulness of the oxygen uptake efficiency slope (OUES) as a variable to compare normal and heart failure subjects implanted with cardiac resynchronization therapy defibrillator (CRT-D) devices. Methods: Exercise tests were performed on a treadmill (modified CAEP protocol) by 18 biventricular patients (post implant ∼ 4wks, NYHA II-III) and 25 normal volunteers. Expired gas was continuously analyzed. Peak Vo2 and Ve/VCO2 slopes were determined from the CPX ventilatory data. The OUES was calculated from the data using then entire exercise duration using the OUES equation VO2=a log Ve+b, where VO2 is oxygen uptake (ml/kg/min) and Ve is minute ventilation (L/min) and the constant “a” is OUES. A comparison of the OUES between the normal and BiV patients was performed. Results: Summary data are illustrated in the table. The mean OUES and peak VO2 for the normal volunteers was significantly higher compared to CRT-D baseline. VE/VCO2 slope was significantly lower in normal compared to CRT-D baseline. Conclusion: Our results suggest that OUES is an objective measure of cardiopulmonary reserve that can potentially discriminate between normal and heart failure subjects. This may be a useful tool for the detection of functional status changes.*ResultsNormalCRT-D BaselineOUES37.4+9.117.8+6.5*Peak VO236.5+7.715.2+4.4*VE/VCO2 slope31.3+.537.7+1.2*p<0.001 compared to normals

Estimating Capacity Utilization from Survey Data

In this paper, we review the history and concepts behind the Federal Reserve&amp;amp;#x27;s measures of capacity and capacity utilization, summarize the methods used to construct the measures, and describe the principal source data for these measures--the Census Bureau&amp;amp;#x27;s Survey of Plant Capacity. We show that the aggregate manufacturing utilization rate from the Survey of Plant Capacity does not exhibit the &amp;amp;quot;cyclical bias&amp;amp;quot; possessed by utilization rates from the less statistically rigorous utilization rate surveys previously used to estimate the Federal Reserve&amp;amp;#x27;s measures. At the detailed industry level, utilization rates from the Survey of Plant Capacity for several industries do appear to possess a cyclical bias, but we demonstrate that this bias is removed in the construction of the Federal Reserve capacity measures. We further show that the Federal Reserve measures, by combining the Census survey utilization rates with other indicators of capacity, do not discard significant information contained in the Census rates. In fact, the Federal Reserve procedures add to the predictive content of the Census utilization rates in models of capital spending, capacity expansion, and changes in price inflation.

Chronicle of the Liquidity Effect Foretold

Conventional accounts of the immediate mechanism whereby the Federal Reserve raises short-term interest rates require the Fed to reduce the supply of reserves in order to raise interest rates. This paper shows in popular monetary models that although the Fed can have an immediate effect on interest rates purely by announcing a change in the target without changing reserves, these models imply that by the end of the maintenance period, one should see some combination of a drop in nonborrowed reserves, drop in excess reserves, or increase in borrowed reserves in order to ratify the Fed's intended interest rate hike. Using aggregate reserves of depository institutions data, this paper looks at what happens to various reserve measures during maintenance periods in which there was a change in the Fed funds target. An institutionally motivated time-varying parameter model is built to predict each monetary aggregate. Using three different measures of monetary policy, two of an unanticipated change in the funds target and the change in the target itself, a negative correlation between the target change and what happens to three of the five corresponding reserve aggregates is found. The sign and magnitude of the finding for the target is consistent with the standard results from the literature regarding the liquidity effect. Nevertheless, these results are not replicated when using the proxies for unanticipated changes.

The myocardial performance index during low-dose dobutamine echocardiography in control subjects and patients with a recent myocardial infarction: a new index of left ventricular functional reserve?

Background Wall-motion analysis during low-dose dobutamine echocardiography (LDDE) is a semiquantitative measure of left ventricular contractile reserve after myocardial infarction (MI). The Doppler echocardiographic myocardial performance index (MPI) is a quantitative measure of combined left ventricular systolic and diastolic function. We sought to characterize the changes in MPI during LDDE in control subjects and patients with MI, and to describe the relation of these changes to changes in regional systolic function. Methods MPI was obtained at rest and during LDDE (10 μg/kg/min) in 25 healthy volunteers (group 1) and 50 patients with a recent MI. Patients were divided into two subsets; those with (n = 23; group 2A) and those without (n = 27; group 2B) a contractile reserve defined as an improvement of wall motion in more than two contiguous infarct-zone segments during LDDE. ΔMPI was defined as the change from rest to LDDE. Results MPI decreased significantly during LDDE in groups 1 and 2A, whereas MPI increased in group 2B (ΔMPI = 0.12 ± 0.04 and 0.10 ± 0.08 vs −0.03 ± 0.08, P < .0001). On multivariate analysis, Δwall-motion score index predicted ΔMPI (β = 0.65, P < .0001) independently of age, sex, and the dobutamine-induced change in heart rate and systolic blood pressure. Conclusions Data suggest that the change in MPI during LDDE may provide a simple and quantitative measure of overall left ventricular functional reserve in patients with a recent MI.

Mortality in patients with microvascular disease.

Patients with chest pain/ischemic cardiac disease and normal coronary arteriography are thought to have a benign prognosis despite diminished quality of life. Many patients with hypertension fall into this group, at least in the early stage of their disease. Whether abnormalities in coronary flow reserve in these patients are associated with increased morbidity and mortality is unknown. One hundred sixty-eight patients with chest pain/ischemic cardiac disease and normal coronary angiograms who underwent invasive measures of coronary flow reserve were followed longitudinally. Mortality and quality of life were ascertained by query of the national death index and telephone administration of standardized questionnaires. Patient follow-up occurred at a mean of 8.5 years. In the abnormal coronary flow reserve group, 12 deaths (20%) were documented in 60 patients compared with eight out of 108 patients (7%; p=0.016) with normal coronary flow reserve. Coronary flow reserve did not predict impairment in functional health status in long-term follow-up. Thus, invasive measures of coronary flow reserve in patients with chest pain/ischemic cardiac disease and normal coronary angiograms predicted increased mortality. Surviving patients with chest pain/ischemic cardiac disease and normal coronary angiograms have significant morbidity.

AIRarg and AIRgluc as predictors of insulin secretory reserve

Various brief metabolic tests have been proposed as surrogate measures of insulin secretory reserve, which is normally determined by the more complicated and labor-intensive method of glucose potentiation of arginine-induced insulin secretion (GPAIS). This article provides correlations between insulin responses to intravenous arginine (AIRarg) and intravenous glucose (AIRgluc) in 39 normal control subjects in whom insulin secretory reserve was measured by GPAIS. The correlation coefficients were .78 and .77, respectively, both of which were highly statistically significant ( P < .001). These results indicate that either AIRarg or AIRgluc, tests that can be performed in less than 15 minutes, can be used as reliable predictors of insulin secretory reserve in normal controls and, presumably, in recipients of islet and pancreas transplantation.

Anti-Müllerian hormone and its role in ovarian function

Anti-Müllerian hormone (AMH) is expressed after birth in the ovary in the granulosa cells of healthy, small growing follicles. We have shown that AMH affects two important regulatory steps during folliculogenesis. At initial recruitment, AMH inhibits recruitment of primordial follicles into the growing pool, while at cyclic recruitment AMH lowers the FSH-sensitivity of follicles. In these ways, AMH plays an important role in regulation of ovarian follicle growth. AMH serum level is a strong candidate marker for ovarian reserve in women. In normo-ovulatory women, AMH serum levels correlated strongly with the number of antral follicles. In addition, AMH is a strong predictor for the number of oocytes retrieved in patients undergoing IVF treatment. The convenience of determination and its relative stable expression during the menstrual cycle indicate that further validation of the use of serum AMH is recommended as a clinical measure of ovarian reserve.