High Basal Metabolism Research Articles

Effect of Concentrate Feeding Frequency on Growth Performance of Sirohi Goat Kids

Background: The growth rate and body weight increased with increment in feed frequencies due to microbial activities enhancing nutrient absorption in the animal’s body (Yaunas et al., 2014, Bawala et al., 2009). The efficacy of growth by increased feeding frequency is due to a large improvement in the efficiency of food utilization. Smaller ruminants require more frequent feedings than larger ruminants because of their higher basal metabolism. Methods: The effects of concentrate feeding frequency on growth performance were assessed in a three-month trial including twenty-one female Sirohi goat kids. Three groups (T1, T2 and T3) containing concentrate were randomly assigned to feed the Sirohi goat kids once, twice, or three times a day. Throughout the ninety-day trial, uniform management techniques and feeding like green or dry fodder were kept up. Each animal was given an exact quantity of food and water each morning during the trial and the remaining feed and water were weighed the next morning. Result: Total daily feed intake was significantly (P less than 0.01) higher in T3 (885.88±4.06 g/d) than in T2 (775.03±7.52 g/d) and T1 (702.54±5.78 g/d). Average daily weight gain (ADG) was significantly (P less than 0.01) higher in T3 (43.68±1.8 g) than in T1 (32.30±2.61 g) and T2 (37.73±2.42 g). Non-significantly differing feed conversion ratio (3.06±0.31) in T3 than in T2 (3.16±0.29) and T1 (3.39±0.31), indicating a positive impact of thrice-a-day concentrate feeding on feed intake and growth but not affect feed efficiency in goat kids.

Selective breeding for high voluntary exercise in mice increases maximal (VO2max), but not basal metabolic rate.

In general, sustained high rates of physical activity require a high maximal aerobic capacity (VO2max), which may also necessitate a high basal aerobic metabolism (BMR), given that the two metabolic states are linked via shared organ systems, cellular properties, and metabolic pathways. We tested the hypotheses that (a) selective breeding for high voluntary exercise in mice would elevate both VO2max and BMR, and (b) these increases are accompanied by increases in the sizes of some internal organs (ventricle, triceps surae muscle, liver, kidney, spleen, lung, brain). We measured 72 females from generations 88 and 96 of an ongoing artificial selection experiment comprising 4 replicate High Runner (HR) lines bred for voluntary daily wheel-running distance and 4 non-selected Control (C) lines. With body mass as a covariate, HR lines as a group had significantly higher VO2max (+13.6%, P<0.0001), consistent with previous studies, but BMR did not significantly differ between HR and C lines (+6.5%, P=0.181). Additionally, HR mice did not statistically differ from C mice for whole-body lean or fat mass, or for the mass of any organ collected (with body mass as a covariate). Finally, mass-independent VO2max and BMR were uncorrelated (r=0.073, P=0.552) and the only statistically significant correlation with an organ mass was for VO2max and ventricle mass (r=0.285, P=0.015). Overall, our results indicate that selection for a behavioral trait can yield large changes in behavior without proportional modifications to underlying morphological or physiological traits.

Relationship Between Weight Status And Basal Metabolism In Schoolchildren

There is currently a scientific trend to study the association between energy balance and its impact on health from the earliest stages of life. The aim of this study was to examine whether diet quality and physical activity moderate the association between weight status and basal metabolism in a sample of Murcian primary school children aged 8-12 years. Basal metabolism was calculated according to height, sex, and weight, with fixed coefficients following validated formulae. Physical activity was measured with the Krece-Plus test; the KIDMED questionnaire was used to quantify diet quality and nutritional status was assessed by body mass index (BMI; kg/m2) adjusted for sex and age. The results obtained indicate that overweight schoolchildren have a higher basal metabolism than their normal-weight peers considering their diet quality and physical activity level (p&amp;lt;.001, for both). Also, the effects of weight status on basal metabolism may be moderated by diet quality (p&amp;lt;.05) but not by physical activity (p&amp;gt;.05). These results may be of particular interest to educational and health personnel since generating strategies to improve school children’s eating habits, especially towards higher diet quality, could be vital as a method to increase basal metabolic energy expenditure and their overall health.

Influence of the Basal Metabolic Profile on the Evolution of the Pediatric Patient with Obesity

Purpose: To study how basal metabolism influences the somatometric evolution of the child and adolescent population with obesity in a pediatric endocrinology clinic. Material and Methods: Study of the entire population diagnosed with childhood obesity in a tertiary hospital by means of a multichannel impedanceometry study, TANITA BF 430. Results: 100 patients were selected by chance and studied from a database with 1400 records. Most of the patients who attend to these consultations for obesity are girls, between 8 and 11 years old. All the patients studied had a basal metabolism lower than the calculated theoretical ideal. The group of boys at the beginning of their follow-up showed a higher basal metabolism and more similar than the group of girls. Girls had a higher amount of fat mass compared to boys at the beginning of their follow up. After their first year of follow-up, both groups achieved a decrease in the percentage of fat mass, double in the case of boys compared to girls. After three years of the study, it was observed that 54% of the boys achieved a reduction in their FM compared to 36% of the girls. In overall terms, weight reduction is not achieved in this pediatric population. However it is observed a decrease in fat content in the medium term (1-3 years). The reduction of this fat mass could be a protection factor against cardiovascular diseases in adults. Given the same adherence to nutritional programs, it is believed that physical exercise rates influence this reduction. It was also observed that the most relevant data in the evolution of obesity in these patients is the basal metabolism that they present at the beginning of their follow-up. Discussion: Childhood obesity is a problem of increasing importance in our society. Understanding its characteristics would allow different strategies to be taken for a better treatment and diagnosis of these cases. Boys, in general, achieve a greater reduction in fat mass in the same follow-up time. Due to sexual dimorphism, or a higher rate of physical activity. Bioelectrical impedanceometry measurement is a simple, cheap and easy to use method in clinical practice to evaluate the energy consumption and the body composition of the patient. In “healthy child” health programs and even in schools, an impedanceometry machine could be purchased to focus physical activity efforts on those boys and girls with a lower basal metabolism, adding a greater consumption factor such as physical exercise. Thus, it would be possible to increase the requirements and the basal metabolism of the patient would increase, favoring the loss of fat mass. Regarding the use of conventional scales, in this type of patients, if we only look at the weight variable, a bias could be created since it would not be noticed that there has been a decrease in fat content at the cost of an increase in muscle mass. Conclusion: We consider that it should be recommendable to supply with a multichannel impedanceometry every pediatric endocrine consultation room as it is a non-invasive, and easy-to-use test that can provide a great amount of information about the evolution of these patients, since we believe that focusing efforts on those boys and girls who have a worse basal metabolism could contribute to improving the efficiency and effectiveness of the scarce health resources that we have.

Solubilized ubiquinol for preserving corneal function

Defective cellular metabolism, impaired mitochondrial function, and increased cell death are major problems that adversely affect donor tissues during hypothermic preservation prior to transplantation. These problems are thought to arise from accumulated reactive oxygen species (ROS) inside cells. Oxidative stress acting on the cells of organs and tissues preserved in hypothermic conditions before surgery, as is the case for cornea transplantation, is thought to be a major reason behind cell death prior to surgery and decreased graft survival after transplantation. We have recently discovered that ubiquinol – the reduced and active form of coenzyme Q10 and a powerful antioxidant – significantly enhances mitochondrial function and reduces apoptosis in human donor corneal endothelial cells. However, ubiquinol is highly lipophilic, underscoring the need for an aqueous-based formulation of this molecule. Herein, we report a highly dispersible and stable formulation comprising a complex of ubiquinol and gamma cyclodextrin (γ-CD) for use in aqueous-phase ophthalmic products. Docking studies showed that γ-CD has the strongest binding affinity with ubiquinol compared to α- or β-CD. Complexed ubiquinol showed significantly higher stability compared to free ubiquinol in different aqueous ophthalmic products including Optisol-GS® corneal storage medium, balanced salt solution for intraocular irrigation, and topical Refresh® artificial tear eye drops. Greater ROS scavenging activity was noted in a cell model with high basal metabolism and ROS generation (A549) and in HCEC-B4G12 human corneal endothelial cells after treatment with ubiquinol/γ-CD compared to free ubiquinol. Furthermore, complexed ubiquinol was more effective at lowering ROS, and at far lower concentrations, compared to free ubiquinol. Complexed ubiquinol inhibited lipid peroxidation and protected HCEC-B4G12 cells against erastin-induced ferroptosis. No evidence of cellular toxicity was detected in HCEC-B4G12 cells after treatment with complexed ubiquinol. Using a vertical diffusion system, a topically applied inclusion complex of γ-CD and a lipophilic dye (coumarin-6) demonstrated transcorneal penetrance in porcine corneas and the capacity for the γ-CD vehicle to deliver drug to the corneal endothelium. Using the same model, topically applied ubiquinol/γ-CD complex penetrated the entire thickness of human donor corneas with markedly greater ubiquinol retention in the endothelium compared to free ubiquinol. Lastly, the penetrance of ubiquinol/γ-CD complex was assayed using human donor corneas preserved for 7 days in Optisol-GS® per standard industry practices, and demonstrated higher amounts of ubiquinol retained in the corneal endothelium compared to free ubiquinol. In summary, ubiquinol complexed with γ-CD is a highly stable composition that can be incorporated into a variety of aqueous-phase products for ophthalmic use including donor corneal storage media and topical eye drops to scavenge ROS and protect corneal endothelial cells against oxidative damage.

Adaptive differentiation of growth, energetics and behaviour between piscivore and insectivore juvenile rainbow trout along the Pace-of-Life continuum.

Adaptive trade-offs are fundamental mechanisms underlying phenotypic diversity, but the presence of generalizable patterns in multivariate adaptation and their mapping onto environmental gradients remain unclear. To understand how life history affects multivariate trait associations, we examined relationships among growth, metabolism, anatomy and behaviour in rainbow trout juveniles from piscivore versus insectivore ecotypes along an experimental gradient of food availability. We hypothesized that (a) selection for larger size in piscivorous adults would select for higher juvenile growth at the cost of lower active metabolism; (b) elevated growth of piscivores would be supported by a greater productivity of their natal stream and more proactive foraging behaviours and (c) general patterns of multivariate trait associations would match the predictions of the Pace-Of-Life Syndrome. Relative to insectivores, piscivorous fry showed a pattern of higher growth (+63%), maximum food intake (+33%), growth efficiency (+41%) and standard metabolic rate (SMR; +47%), but lower active metabolic capacity (maximum metabolic rate [MMR; -17%], aerobic scope [AS; -48%]), suggesting that faster piscivore growth is supported by greater food intake and digestive capacity but is traded-off against lower scope for active metabolism. A similar trade-off appeared among organ systems, with piscivorous fry exhibiting an 83% greater investment in average mass of organs associated with food consumption and processing (i.e. stomach and intestine), but an apparently smaller relative investment in organs involved in cardiovascular or cognitive activities (heart and brain, respectively). Higher invertebrate drift in their natal rearing habitat, quicker behavioural transition to a novel food source and lower anxiety after a frightening event in piscivorous fry suggest that faster growth requires both proactive foraging behaviours and higher prey availability in the environment. Finally, the sampling of replicate insectivore populations confirmed their lower juvenile growth (-73% on average) and reduced environmental productivity of their natal streams (-45% lower drift abundance) relative to the piscivore ecotype. Our results suggest that selection for large adult body size influences selection on high juvenile growth, high basal metabolism and proactive behaviours, and that the intense phenotypic divergence between piscivorous and insectivorous rainbow trout may be constrained by environmental productivity.

Tonic TCR Signaling Inversely Regulates the Basal Metabolism of CD4+ T Cells.

The contribution of self-peptide-MHC signaling in CD4+ T cells to metabolic programming has not been definitively established. In this study, we employed LLO118 and LLO56, two TCRtg CD4+ T cells that recognize the same Listeria epitope. We previously have shown that LLO56 T cells are highly self-reactive and respond poorly in a primary infection, whereas LLO118 cells, which are less self-reactive, respond well during primary infection. We performed metabolic profiling and found that naive LLO118 had a dramatically higher basal respiration rate, a higher maximal respiration rate, and a higher glycolytic rate relative to LLO56. The LLO118 cells also exhibited a greater uptake of 2-NBD-glucose, in vitro and in vivo. We extended the correlation of low self-reactivity (CD5lo) with high basal metabolism using two other CD4+ TCRtg cells with known differences in self-reactivity, AND and Marilyn. We hypothesized that the decreased metabolism resulting from a strong interaction with self was mediated through TCR signaling. We then used an inducible knock-in mouse expressing the Scn5a voltage-gated sodium channel. This channel, when expressed in peripheral T cells, enhanced basal TCR-mediated signaling, resulting in decreased respiration and glycolysis, supporting our hypothesis. Genes and metabolites analysis of LLO118 and LLO56 T cells revealed significant differences in their metabolic pathways, including the glycerol phosphate shuttle. Inhibition of this pathway reverts the metabolic state of the LLO118 cells to be more LLO56 like. Overall, these studies highlight the critical relationship between peripheral TCR-self-pMHC interaction, metabolism, and the immune response to infection.

Retrospective analysis of the frequency and contributory causes of ascites syndrome in broilers in South Banat

Ascites syndrome is a multi-factorial, noncontagious disease of broilers. Chickens selected for rapid growth have a high basal metabolism and consequently increased demands for oxygen. Poor environmental conditions and other unfavourable factors which reduce the amount of available oxygen cause hypoxia, pulmonary hypertension, right ventricular dilation and right heart failure, which results in generalized passive hyperaemia of organs and ascites as the most striking gross pathology manifestation. The aim of the study was to investigate, retrospectively, the frequency of the disease in a selected district with widespread poultry production and to identify main factors that contribute to the outbreak of the disease. In the period from 2011 to 2017 ascites syndrome was diagnosed by post mortem examination of chickens in 12 out of 91 flocks with health disorders, examined in the Veterinary Specialized Institute "Pancevo". Based on anamnesis, signs of disease and pathomorphological findings, poor environmental conditions and inadequate feed were identified as main contributory factors. In the majority of cases ascites syndrome occurred in small flocks, raised in unsuitable environmental conditions.

Selection for high activity-related aerobic metabolism does not alter the capacity of non-shivering thermogenesis in bank voles

An intriguing question is how the capacity of non-shivering thermogenesis (NST)—a special mechanism supporting endothermic thermoregulation in mammals—is affected by selection for high exercise metabolism. It has been proposed that high NST could be a mechanism to compensate for a low basal production of heat. On the other hand, high basal or activity metabolism is associated with physiological characteristics such as high performance of the circulatory system, which are also required for achieving a high NST. Here we tested whether selection for high aerobic exercise performance, which correlates with an increased basal metabolic rate, led to a correlated evolution of maximum and facultative NST. Therefore, we measured the NST of bank voles, Myodes (= Clethrionomys) glareolus, from lines selected for 13–14 generations (n=46) for high aerobic metabolism achieved during swimming and from unselected, control lines (n=46). Open-flow respirometry was used to measure the rate of oxygen consumption (V·O2) in anesthetized bank voles injected with noradrenaline (NA). After adjusting for body mass, maximum NST (maximum V·O2 recorded after injection of NA) did not differ between the selected (2.38±0.08mLO2min−1) and control lines (2.36±0.08mLO2min−1; P=0.891). Facultative NST (= maximum NST minus resting metabolic rate of anesthetized animals) did not differ between the selected (1.49±0.07mLO2min−1) and control lines (1.50±0.07mLO2min−1; P=0.985), either. Therefore, our results suggest that NST capacity is not strongly linked to maximum activity-related aerobic metabolic rate.

Super obese behave different from simple and morbid obese patients in the changes of body composition after tailored one anastomosis gastric bypass (BAGUA).

Super obese patients behave different from simple and morbid obese patients when they reach final changes of body composition (BC) after bariatric surgery. This has led us to tailor One Anastomosis Gastric Bypass (BAGUA) to achieve better results in this group of patients. We studied 83 (37 diabetic and 46 nondiabetic BMI 30 and up) patients who completed all evaluation appointment (preoperative, 10 days, 1, 3, 6 and 12 months) after tailored BAGUA for diabesity. We used the Tanita body composition analyzer BC-420 MA by the method of single frequency impedance to analyze the evolution of BC in patients classified by BMI 30 - 34,9, 35 - 50, and >50. While preoperative excess weight presented dramatic decreases after tailored BAGUA in all the groups, super obese have different final BC. Diabetics retained more fat mass and visceral fat, where super obese have double (14 kg) that simple obese patients (6 kg), they lost more muscle mass, and have higher basal metabolism. The final BC is altered in all parameters if diabetes is added. The reduction of the preoperative excess weight is motivated largely by the tailored effect of BAGUA. Patients BMI 30-50 behaved homogeneous in BC after surgery while patients BMI >50 behave different. Super obese lose less weight, retained more fat mass, visceral fat, bone mass, and total water. This effect should be treated by more aggressive surgery by measuring the entire small intestine to make a proper exclusion (tailored) to achieve homogeneous effects.

Pro-oxidant and antioxidant responses in the liver and kidney of wild Goodea gracilis and their relation with halomethanes bioactivation

In mammals, it has been shown that halomethanes (HM) are bioactivated by enzymes such as CYP 2E1 and the theta isoform of GST to produce reactive metabolites. However, in fish, little information is available, although HM can form autochthonously in aquatic environments. This study assessed the effect of HM in dusky splitfin (Goodea gracilis) from three lakes of the Valley of Mexico by analysing specific HM biomarkers as well as a broad range of biomarkers. The concentration of HM was a function of its half-life (higher in deep waters), while its precursors and solar radiation are secondary factors that determine its concentration. The kidney showed higher basal metabolism than the liver, probably because of its function as a haematopoietic and filtration organ. Using integrated biological response version 2 (IBRv2), it was found that the hepatic and renal O₂· content is a pro-oxidant force capable of inducing oxidative stress (ROOH, TBARS and RC=O). Early damage was found to be dependent on low concentrations of HM in Major Lake, whereas late damage was observed in fish exposed to higher concentrations of HM in Zumpango Lake and Ancient Lake. The activities of enzymes involved in antioxidant defence seemed to be inefficient. The quantitative assessment of biomarkers (ANOVA) and the estimate of parameter A obtained from IBRv2 provided different information. However, the data support the greater predictive power of IBRv2, but it requires a series of interrelated biomarkers to infer these possibilities. G. gracilis presents marked patterns of adaptation, which are dependant on the HM concentrations in environmental mixtures, although the response is complex and many toxicants could induce similar responses.

A review on the role of quinones in renal disorders

Quinones are electron and proton carriers that play a primary role in the aerobic metabolism of virtually every cell in nature. Most physiological quinones are benzoquinones. They undergo highly regulated redox reactions in the mitochondria, Golgi apparatus, plasma membrane and endoplasmic reticulum. Important consequences of these electron transfer reactions are the production of and protection against reactive oxygen species (ROS). Quinones have been extensively studied for both their cytotoxic as well as cellular protective properties and they have been particularly useful in rational drug design. The role of quinones in medicine is explored in this literature review with a particular focus on renal diseases. Due to their high basal metabolism and detoxification role, the kidneys are particularly sensitive to oxidative stress. Regardless of the underlying etiology, ROS plays an important role in both acute kidney injury (AKI) and chronic kidney diseases (CKD). Depending on the oxidative state of the kidney, quinones can be nephrotoxoic or nephro-protective. Many factors play a role in the interaction between quinones and the kidney and the consequences of this are just beginning to be explored.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-2-139) contains supplementary material, which is available to authorized users.

Proteomic analysis of liver development of lean Pekin duck (Anas platyrhynchos domestica)

The liver plays vital roles in digestion, metabolism and immune defense. To elucidate the molecular mechanism of nutrient metabolism and antioxidation of lean Pekin duck liver from hatching to slaughter, the proteome changes were investigated using 2-DE, MS, quantitative real-time PCR and bioinformatics. A total of 59 differentially expressed proteins were identified. Proteins involved in transportation were highly up-regulated in newborn ducks whereas 37 proteins associated with metabolism, defense and antioxidation were up-regulated in adult ducks. The over-expression of proteins at the last developmental stage presumably occurs to fulfill the needs of multiple functions of the liver. However, the over-expressed proteins related to transportation during the first developmental stage are involved in maintaining the high basal metabolism of newborn ducks. The functional enrichment analysis also confirmed these results. Furthermore, the protein interaction network predicted 28 proteins acting as key nodes for liver development. The validated expression between proteins and genes provides us target genes for future genetic analyses to improve the health and performance of these ducks. These significant advanced proteome data expand our knowledge on the physiology of the duck liver, thereby providing a potentially valuable foundation for molecular breeding to enhance feed efficiency and immunity and for optimizing the feeding strategy.

Dynamical Properties of BOLD Activity from the Ventral Posteromedial Cortex Associated with Meditation and Attentional Skills

Neuroimaging data suggest a link between the spontaneous production of thoughts during wakeful rest and slow fluctuations of activity in the default mode network (DMN), a set of brain regions with high basal metabolism and a major neural hub in the ventral posteromedial cortex (vPMC). Meta-awareness and regulation of mind-wandering are core cognitive components of most contemplative practices and to study their impact on DMN activity, we collected functional MRI (fMRI) data from a cohort of experienced Zen meditators and meditation-naive controls engaging in a basic attention-to-breathing protocol. We observed a significant group difference in the skewness of the fMRI BOLD signal from the vPMC, suggesting that the relative incidence of states of elevated vPMC activity was lower in meditators; furthermore, the same parameter was significantly correlated with performance on a rapid visual information processing (RVIP) test for sustained attention conducted outside the scanner. Finally, a functional connectivity analysis with the vPMC seed revealed a significant association of RVIP performance with the degree of temporal correlation between vPMC and the right temporoparietal junction (TPJ), a region strongly implicated in stimulus-triggered reorienting of attention. Together, these findings suggest that the vPMC BOLD signal skewness and the temporal relationship of vPMC and TPJ activities reflect the dynamic tension between mind-wandering, meta-awareness, and directed attention, and may represent a useful endophenotype for studying individual differences in attentional abilities and the impairment of the latter in specific clinical conditions.

Graph theoretical analysis of structural and functional connectivity MRI in normal and pathological brain networks

Graph theoretical analysis of structural and functional connectivity MRI data (ie. diffusion tractography or cortical volume correlation and resting-state or task-related (effective) fMRI, respectively) has provided new measures of human brain organization in vivo. The most striking discovery is that the whole-brain network exhibits "small-world" properties shared with many other complex systems (social, technological, information, biological). This topology allows a high efficiency at different spatial and temporal scale with a very low wiring and energy cost. Its modular organization also allows for a high level of adaptation. In addition, degree distribution of brain networks demonstrates highly connected hubs that are crucial for the whole-network functioning. Many of these hubs have been identified in regions previously defined as belonging to the default-mode network (potentially explaining the high basal metabolism of this network) and the attentional networks. This could explain the crucial role of these hub regions in physiology (task-related fMRI data) as well as in pathophysiology. Indeed, such topological definition provides a reliable framework for predicting behavioral consequences of focal or multifocal lesions such as stroke, tumors or multiple sclerosis. It also brings new insights into a better understanding of pathophysiology of many neurological or psychiatric diseases affecting specific local or global brain networks such as epilepsy, Alzheimer's disease or schizophrenia. Graph theoretical analysis of connectivity MRI data provides an outstanding framework to merge anatomical and functional data in order to better understand brain pathologies.

Basal Cerebral Metabolism May Modulate the Cognitive Effects of Aβ in Mild Cognitive Impairment: An Example of Brain Reserve

Inverse correlations between amyloid-beta (Abeta) load measured by Pittsburgh Compound-B (PiB) positron emission tomography (PET) and cerebral metabolism using [(18)F]fluoro-2-deoxy-d-glucose (FDG) in Alzheimer's disease (AD) patients, suggest local Abeta-induced metabolic insults. However, this relationship has not been well studied in mild cognitive impairment (MCI) or amyloid-positive controls. Here, we explored associations of Abeta deposition with metabolism via both region-of-interest-based and voxel-based analyses in amyloid-positive control subjects and patients with MCI or AD. Metabolism in parietal and precuneus cortices of AD patients was negatively correlated with PiB retention locally, and more distantly with PiB retention in frontal cortex. In amyloid-positive controls, no clear patterns in correlations were observed. In MCI patients, there were essentially no significant, negative correlations, but there were frequent significant positive correlations between metabolism and PiB retention. Metabolism in anterior cingulate showed positive correlations with PiB in most brain areas in MCI, and metabolism and PiB retention were positively correlated locally in precuneus/parietal cortex. However, there was no significant increase in metabolism in MCI compared to age-matched controls, negating the possibility that Abeta deposition directly caused reactive hypermetabolism. This suggests that, in MCI, higher basal metabolism could either be exacerbating Abeta deposition or increasing the level of Abeta necessary for cognitive impairment sufficient for the clinical diagnosis of AD. Only after extensive Abeta deposition has been present for longer periods of time does Abeta become the driving force for decreased metabolism in clinical AD and, only in more vulnerable brain regions such as parietal and precuneus cortices.

Missing organic carbon in Eocene marine sediments: Is metabolism the biological feedback that maintains end‐member climates?

Ocean chemistry is affected by pCO2 in the atmosphere by increasing the dissolution of solid calcium carbonate and elevating the dissolved inorganic carbon concentrations in seawater. Positive feedbacks between the ocean and atmosphere can maintain high atmospheric pCO2 and affect global climate. We report evidence for changes in the oceanic carbon cycle from the first high‐quality organic carbon (Corg) data set of Eocene sediments beneath the equatorial Pacific upwelling region (Leg 199 of the Ocean Drilling Program). Eocene Corg mass accumulation rates (MARs) are 10 times lower than Holocene rates, even though expected Corg MARs estimated from biogenic‐barium MARs (an indicator of biological production) equal or exceed modern fluxes. What happened to the missing Corg? Recent advances in ecology and biochemical kinetics show that the metabolism of nearly all animals, marine and terrestrial, is positively correlated by first principles to environmental temperatures. The approximately 10°C abyssal temperature difference from Eocene to Holocene should have radically reduced pelagic Corg burial, as we observe. We propose that higher basal metabolism and nutrient utilization/recycling rates in the Eocene water column and surface sediments precluded Corg sediment burial in the pelagic ocean. Increased rates of metabolism, nutrient utilization, and lowered Corg sedimentation caused by increased temperature may have acted as a biological feedback to maintain high atmospheric pCO2 and hothouse climates. Conversely, these same parameters would reverse sign to maintain low pCO2 when temperatures decrease, thereby maintaining “icehouse” conditions during cold climate regimes.

Microcalorimetric studies inBiomphalaria glabrata: The influence ofSchistosoma mansoni on the basal metabolism

1. The heat production of the snail,Biomphalaria glabrata, was determined inSchistosoma mansoni infected and uninfected animals. 2. Untreated and uninfected snails do not show a significantly higher heat production (1.02 μW/mg wet weight) when compared with untreated infected snails (0.96 μW/mg). A significant difference can be demonstrated by eliminating movements of the snail. The average heat production is 0.22 μW/mg wet weight in uninfected snails and 0.30 μW/mg (P<0.001) in infected animals. Infected snails restrict their movements to compensate for the higher basal metabolism. The physiological implications and possible controlling mechanisms are discussed.

ACTIVATING EFFECT CF PHOTO-METRAZOL ON THE EEG OF VARIOUS PSYCHOSES AND NEUROSES CASES

Summary PHOMAC was given to 176 psychoses and neuroses cases and clinical as well as biological investigation was set. The reactions to PHOMAC were classified into three types, namely, myoclonic response, convulsive response. and mixed response. Patients of manic depressive psychosis. neurosis, psychogenic reaction (hysteria), chronic alcoholism, and normal persons were found to show myoclonic responses only and patients of atypical endozenous pzychosis, psychopathy. and schizophrenia showed either myoclonic response or convulsive response, of which typical schizophrenia responded with the former only while epileptics showed all the three types. Convulsive response tendes to appear in cpileptics and those in whom epileptic factors could be suspected clinico-symptonatologically or in some other respects. Of schizophrenics, the group belonging to catatonic type gave evidently lower myoclonic threshold values than the other types. To compare the myoclonic threshold of each setting and with the same of normal persons as criterion, the cases of catatonia, chunk alcoholism, psychopithy, atypiczal endogenous psychosis and epilepsy showed low threshold values, while those of schizophrenia (excluding catatonia), manic depressive psychosis and neurosis returned high threshold values and psychogenic reaction cases (hysteria:) proved no significant disparity. in their values from normal persons. With the improvement of the clinical manifestations, the myoclonic threshold values of schizophrenics went lowered, whereas those of epileptics and endogenous psychosis upward. No such fluctuation was delectable with manic depressive psychotics, neurotics and the patients of psychogenic reaction (hysteria). As to the myoclonic threshold values of the cases of psychoses and neuroses represented by schizophrenia and manic depressive psychosis, the values were lower in those under 20 yrs of age than in those above it. The same availed in those with higher basal metabolism than in those with normal or lowered basal metabolic rate, again, in those showing abnormal E. E. G. under resting state with closed eyes than in those showing normal E. E. G., further, in slender persons than in fat and stout persons and, in those in states of lower vagotonic activation than those in higher vagotonic activation, respectively. Any sex difference was hardly observable concerning variance in threshold value.

Electromyographical studies on Graves' disease.

The characteristics of the EMG of Graves' disease is that the dis-tribution of spike discharge becomes more irregular than normal during, voluntary muscle contraction. This irregularity is due to the following 3 factors. 1. The spike discharges of different motor units are apt to approach. 2. The fluctuation of impulse interval of single motor unit becomes remarkable. 3. Mean impulse interval becomes shorter. This phenomenon shows a tendency of increase or decrease with toxic symptoms, i.e., high basal metabolism, tachycardia and the instability of the pulse. It is still unknown how this fluctuation occurs in what part of the motor unit. Further study is required.