Sex-associated differences in cold-induced UCP1 synthesis in rodent brown adipose tissue

OBJECTIVE: To evaluate the usefulness of new ELISA for human parvovirus B19 (B19) antibodies and PCR for the diagnosis of acute onset of B19 polyarthritis. METHODS: We evaluated the reproducibility and sensitivity on the detection of anti-B19 antibody by ELISA using recombinant VP-1 and VP-2 (empty particle), and then studied for the prevalence of IgM and IgG B19 antibody in 125 samples for anti-B19 tests. The random study on anti-B19 antibody assay as well as PCR for B19-DNA was also performed in 130 cases with acute onset of arthritis excluding those with known origins, 224 with rheumatoid arthritis and 149 with other categories. RESULTS: The results by using B19-empty particle ELISA were reproducible and showed the assay was a sensitive way for clinical use. IgM anti-B19 antibodies were positive not only in all samples from erythema infectiosum, but also often in those from hemolytic anemia, pure red cell aplasia, fetal hydrops, hepatic injury, fever of unknown origin. Among 130 with acute onset of arthritis, 21 showed positive tests for IgM anti-B19 antibody and/or B19 DNA. On the other hand, 4 among 224 patients with rheumatoid arthritis were positive for IgM anti-B19 antibody, but all of 149 in control group were negative for IgM anti-B19 antibodies and for B19 DNA. CONCLUSION AND DISCUSSION: Anti-B19 ELISA using B19-empty particle which has been introduced as a routine test system, is a useful tool for the diagnosis of acute onset of B19 arthritis. An additional examination using PCR for B19 DNA may contribute for understanding persistent B19 polyarthritis or reactivation of B19 infection.     

Use of cytosolic triacylglycerol hydrolysis products and of exogenous fatty acid for the synthesis of triacylglycerol secreted by cultured rat hepatocytes

In this study, we examined whether chronic severe diabetes may affect ischaemic and post-ischaemic regional myocardial dysfunction in vivo in the dog. Diabetes was chemically induced in randomized animals and major metabolic alterations were observed confirming the severity and chronicity of the diabetes. After 70 days, halothane-anaesthetized dogs underwent a 20-min coronary occlusion, followed by reperfusion. During ischaemia, global left ventricle function (dP/dtmax) was more altered (P<0.005) in diabetics ( n=10) than in controls (n=10), whereas area-at-risk (29+/-2.5% of the left ventricle in diabetics v 32.4+/-1.9% in controls) and ischaemic subendocardial myocardial blood flow (radioactive microsphere technique, 0.11+/-0.02 v 0.10+/-0.03 ml/min/g) were similar. During reperfusion, both groups developed significant (P<0.05) regional myocardial dysfunction (somomicrometry, 41+/-14% of baseline in controls and 66+/-8% in diabetics), whereas the difference between groups was not significant. No dog of either group developed myocardial cell necrosis on tissue histology. Multivariate analyses, including the severity of prior ischaemia and the occurrence of ventricular fibrillation as covariables, confirmed that myocardial stunning was not increased in diabetics, although ischaemia was clearly less-well-tolerated in diabetic dogs as global (dP/dtmax) as well as regional myocardial function were significantly (P<0.05) more altered in diabetics during ischaemia. Whilst alteration of arachidonate and cholesterol metabolism may partly explain this apparent paradox, further studies are required to resolve this issue.     

Sex differences in lean and adipose tissue distribution by magnetic resonance imaging: anthropometric relationships

This study compared total and regional adipose tissue (AT) and lean tissue (LT) distribution measured by magnetic resonance imaging (MRI) in obese, android women (n = 40) and mean (n = 17). Women had significantly (P < 0.01) greater subcutaneous AT (39.6 +/- 11.6 vs 30.7 +/- 7.5 L) but significantly (P < 0.01) less visceral AT (2.5 +/- 1.1 vs 4.8 +/- 2.1 L) and LT (42.8 +/- 4.7 vs 58.2 +/- 6.2 L) compared with men. Segmentation of the visceral AT volume demonstrated that women had significantly (P < 0.01) less intraperitoneal (1.98 +/- 0.84 vs 3.74 +/- 1.61 L) and extraperitoneal AT (0.51 +/- 0.23 vs 1.04 +/- 0.47 L). When the legs, hip and pelvic region, and abdomen and torso regions were compared, women had significantly greater absolute quantities of subcutaneous AT and significantly less LT in all regions (P < 0.01); however, in all regions the relative distribution of both was similar. Anthropometric prediction of MRI-measured total AT gave SEs of 7.7% for women and 7.5% for men, for visceral AT 30% for women and 19% for men. Anthropometric prediction of LT gave SEs of 6.5% for women and 3.6% for men.     

Sex differences in the relation of visceral adipose tissue accumulation to total body fatness

With a newly developed short term enzyme linked immunosorbent assay kit (TOYOBO Co.), in which 2 kinds of anti-EPO monoclonal antibodies were used, we assayed EPO concentration in sera from patients with renal failure and hematological disorders. In this report, the EPO data were analysed in relation to serum iron concentrations, with ferritin and UIBC. In the patients with renal failure, there was no significant correlation between EPO concentration and serum iron, ferritin, nor UIBC concentration. On the other hand, in the patients with hematological disorders, there were two types. One was in patients with iron deficiency anemia, whose serum EPO was negatively correlated to serum iron (r = -0.64) and ferritin (r = -0.59), but positively related to UIBC (r = 0.27). The another was the pattern in patients with aplastic anemia, leukemia and MDS, whose serum EPO positively correlated to iron and ferritin but negatively correlated to UIBC. In the patients with aplastic anemia serum EPO had good correlation to serum iron (r = 0.62), ferritin (r = 0.60) and UIBC (r = -0.46). The relationship of EPO to iron in the patients with leukemia (r = 0.54), and EPO to ferritin in the patients with MDS (r = 0.42) show significantly positive correlation coefficient.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coordinated release of acylation stimulating protein (ASP) and triacylglycerol clearance by human adipose tissue in vivo in the postprandial period

The objective of this study was to determine whether Acylation Stimulating Protein (ASP) is generated in vivo by human adipose tissue during the postprandial period. After a fat meal, samples from 12 subjects were obtained (up to 6 h) from an arterialized hand vein and an anterior abdominal wall vein that drains adipose tissue. Veno-arterial (V-A) gradients across the subcutaneous adipose tissue bed were calculated. The data demonstrate that ASP is produced in vivo (positive V-A gradient) With maximal production at 3-5 h postprandially. The plasma triacylglycerol (TAG) clearance was evidenced by a negative V-A gradient. It increased substantially after 3 h and remained prominent until the final time point. There was, therefore, a close temporal coordination between ASP generation and TAG clearance. In contrast, plasma insulin and non-esterified fatty acid (NEFA) had an early (1-2 h) postprandial change. Fatty acid incorporation into adipose tissue (FIAT) was calculated from V-A glycerol and non-esterified fatty acid (NEFA) differences postprandially. FIAT was negative during the first hour, implying net fat mobilization. FIAT then became increasingly positive, implying net fat deposition, and overall followed the same time course as ASP and TAG clearance. There was a direct positive correlation between total ASP production and total FIAT (r = 0.566, P < 0.05). These data demonstrate that ASP is generated in vivo by human adipocytes and that this process is accentuated postprandially, supporting the concept that ASP plays an important role in clearance of TAG from plasma and fatty acid storage in adipose tissue.     

Regional variation in adipose tissue insulin action and GLUT4 glucose transporter expression in severely obese premenopausal women

Insulin action and GLUT4 expression were examined in adipose tissue of severely obese premenopausal women undergoing gastrointestinal surgery. Fat samples were taken from three different anatomical regions: the subcutaneous abdominal site, the round ligament (deep abdominal properitoneal fat), and the greater omentum (deep abdominal intraperitoneal fat). The stimulatory effect of insulin on glucose transport and the ability of the hormone to inhibit lipolysis were determined in adipocytes isolated from these three adipose depots. Insulin stimulated glucose transport 2-3 times over basal rates in all adipocytes. However, round ligament adipose cells showed a significantly greater responsiveness to insulin when compared to subcutaneous and omental adipocytes. Round ligament fat cells also displayed the greatest sensitivity and maximal antilipolytic response to insulin. We also investigated whether regional differences in fat cell insulin-stimulated glucose transport were linked to a differential expression of the GLUT4 glucose transporter. GLUT4 protein content in total membranes was 5 and 2.2 times greater in round ligament adipose tissue than in subcutaneous and omental fat depots, respectively. Moreover, GLUT4 mRNA levels were 2.1 and 3 times higher in round ligament than in subcutaneous or omental adipose tissues, respectively. Adipose tissue GLUT4 protein content was strongly and negatively associated (r = -0.79 to -0.89, p < 0.01) with the waist-to-hip ratio but not with total adiposity. In conclusion, these results demonstrate the existence of site differences in adipose tissue insulin action in morbidly obese women. The greater insulin effect on glucose transport in round ligament adipocytes was associated with a higher expression of GLUT4 when compared to subcutaneous abdominal and omental fat cells. Moreover, despite the regional variation in GLUT4 expression, an increased proportion of abdominal fat was found to be associated with lower levels of GLUT4 in all adipose regions investigated.     

Intra-abdominal adipose tissue in young children

OBJECTIVE: Intra-abdominal adipose tissue (IAAT) is associated with the metabolic complications of obesity. However the time course for the development of IAAT is not clearly defined because it is generally difficult to measure directly. The purposes of this short communication are to present data supporting the existence of IAAT in young children using direct measurement with computed tomography imaging, and to examine the relationship between IAAT and anthropometric indices in 16 healthy children (6.4 +/- 1.2 years; 24.8 +/- 5.4 kg). DESIGN: Total body fat (6.4 +/- 3.5 kg) and fat free mass (18.4 +/- 3.6 kg) were determined by bioelectrical resistance. Fat distribution was estimated from eight individual skinfold measurements, the ratio of three trunk skinfolds to three extremity skinfolds (0.78 +/- 0.20), and the waist:hip ratio (0.90 +/- 0.08). RESULTS: Mean abdominal subcutaneous adipose tissue (SCAT) was 65.3 +/- 44.8 cm2, and mean IAAT was 8.3 +/- 5.8 cm2. The ratio of IAAT to SCAT was 0.15 +/- 0.08, and the ratio of IAAT to total body fat was 1.44 +/- 0.84 cm2/kg. IAAT was significantly correlated with body weight (r = 0.54; P = 0.03), all skinfold measures (range r = 0.60-0.78; P = 0.02 to 0.0003) except at the calf, fat mass (r = 0.69; P = 0.003), and the trunk to extremity skinfold ratio (r = 0.78; P = 0.0003). There was no significant correlation between IAAT and the waist:hip ratio (r = 0.21). CONCLUSIONS: These preliminary results establish the existence of IAAT in young children and suggest that individual trunk skinfold measurements and the trunk:extremity skinfold ratio provide a better indication of IAAT compared to the waist:hip ratio. However, as with adults, the relationship between intra-abdominal adipose tissue and anthropometry in children is complex.     

Lipoprotein and hormone-sensitive lipases in porcine adipose tissue

Lipoprotein lipase (LPL) is an adipocyte enzyme that cleaves fatty acids from circulating lipoproteins. Fatty acids enter the cell to be oxidized or esterified. Hormone-sensitive lipase (HSL) is an adipocyte enzyme that cleaves fatty acids from intracellular triacylglycerol. The HSL is activated by phosphorylation. Assays for the two lipases are complex because the hydrophobic substrate, triacylglycerol, must be presented as a gum-based suspension or as a detergent-based emulsion to a relatively hydrophilic enzyme. A convenient, stable glycerol/phospholipid suspension of the substrate was used for measurement of porcine adipose tissue LPL and HSL in vitro. This substrate was excellent for LPL. It produced rates five times those using a more complex and less convenient gum-based substrate suspension. The LPL activity was released by heparin, had a pH optimum of approximately 8.5, was activated by serum, and was inhibited by NaCl and protamine. This LPL assay measures enzyme capacity. The same substrate was used to measure an adipose tissue lipase activity that had a pH optimum below 7, was not activated by serum, and was not inhibited by NaCl or protamine. These are all characteristics of HSL. Despite the convenience, this substrate was not appropriate for porcine adipose tissue HSL because the rates were only 30 to 50% of those produced with a more complex, less convenient gum-based substrate suspension. Furthermore, incubation of enzyme or tissue slices with insulin, or agents that elevate cAMP concentration, did not modulate this lipase activity, as expected. These incubations poorly modulated LPL activity.     

Regional differences in anti-Negro prejudice.

"Public opinion polling techniques were employed with 366 randomly selected respondents in eight roughly matched communities in the North and South to investigate anti-Negro prejudice… . in anti-Negro prejudice, externalizing personality findings are of equal importance in the North and South, and socio-cultural and social adjustment factors are considerably more important in the South and account for the sharp differences in the regions." 30 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Activation of cholesterol synthesis in preference to fatty acid synthesis in liver and adipose tissue of transgenic mice overproducing sterol regulatory element-binding protein-2

We investigated the suitability of a lyophilized bovine hemoglobin (LBH) preparation containing various fractions of oxyhemoglobin (O2Hb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) for quality assessment in multicomponent analysis (MCA) of hemoglobin derivatives. It was demonstrated that a stable preparation of these components after reconstitution yields a hemoglobin solution that is spectrophotometrically equivalent with a fresh bovine hemoglobin solution. The preparation was found to be stable for at least 1 year when it is kept at 2-8 degrees C and for 1 h after reconstitution. We determined the fractions of O2Hb, COHb, and MetHb of several LBH preparations, using the complete spectra of 480-650 nm with 2-nm intervals and absorptivities as determined for pure LBH solutions. A field trial involving various types of multiwavelength hemoglobin photometers showed the suitability of LBH as a quality-control material. Computer models of the various common multiwavelength hemoglobin photometers may be useful for establishing more accurate target values of LBH preparations for each type of photometer and for studying the importance of the influence of specific factors such as wavelength selection, absorptivity values, and interfering dyes.     

Intrinsic regulation of blood flow in adipose tissue

Previous studies on intact human subcutaneous tissue have shown, that blood flow remains constant during minor changes in perfusion pressure. This so-called autoregulatory response has not been demonstrable in isolated preparations of adipose tissue. In the present study on isolated, denervated subcutaneous tissue in female rabbits only 2 of 12 expts. revealed an autoregulatory response during reduction in arterial perfusion pressure. Effluent blood flow from the tissue in the control state was 15.5 ml/100 g-min (S.D. 6.4, n = 12) corresponding to slight vasodilatation of the exposed tissue. Following total ischemia all experiments showed a period with reactive hyperemia, and both duration of hyperemia and excess flow was related to the duration of the ischemia. This response therefore seems more resistant to the experimental procedure, while autoregulation of blood flow to lowered pressure is more susceptible to surgical exposure of the tissue. During elevation of arterial perfusion pressure blood flow in the isolated tissue showed a transient increase and then almost returned to the level during normotension, indicating an elevated vascular resistance. Raising of venous pressure elicited vasoconstriction with pronounced flow reduction. These two reactions may be important for local regulation of blood flow in subcutaneous tissue during orthostatic changes in arterial and venous pressure. It is concluded that the response in adipose tissue to changes in arterial pressure (autoregulation), venous pressure and total ischemia appear to be elicited by different mechanisms.     

Regional, developmental, and cell cycle-dependent differences in mu, delta, and kappa-opioid receptor expression among cultured mouse astrocytes

Of all skeletal muscles examined in the rat, the spinotrapezius (S) and diaphragm (D) have the closest fiber-type composition. However, their oxidative capacities differ by two- to threefold. We have developed an intravital microscopy preparation to study diaphragm microcirculation in vivo. Using this preparation and the standard spinotrapezius model first described by S. D. Gray (1973, Microvasc. Res. 5, 395-400), we tested the hypothesis that pronounced microcirculatory differences would exist between these two muscles as a function of their disparate oxidative capacities. The lineal density of all capillaries in the spinotrapezius was 33.6 +/- 1.5 compared to 65.1 +/- 3.3 capillaries/mm in the diaphragm (P < 0.001). In the diaphragm compared with the spinotrapezius muscle, a significantly (P < 0.05) greater proportion of capillary countercurrent flow (D, 29 +/- 6% vs 8 +/- 6%) existed. Within both muscles, there was a similar proportion of capillaries supporting red blood cell (RBC) flow (S, 89 +/- 7% vs D, 92 +/- 2%). However, the diaphragm supported significantly (P < 0.001) greater intracapillary RBC velocities (D, 302 +/- 11 vs S, 226 +/- 9 micron/s) and fluxes (D, 33.4 +/- 1.1 vs S, 19.2 +/- 2.1 cells/s) compared with the spinotrapezius. Capillary "tube" hematocrit was greater (P = 0.01) in the diaphragm (0.32 +/- 0.02) than in the spinotrapezius (0.22 +/- 0.03) muscle. These data demonstrate that microcirculatory flow characteristics in resting muscle can be regulated independent of muscle fiber-type composition and may be related to muscle oxidative capacity.     

Adrenergic receptors mediating depolarization in brown adipose tissue

Adrenergic receptors mediating depolarization in in vitro neonatal rat brown adipose tissue (BAT) have been characterized by use of adrenergic agonists and antagonists. Releasable endogenous catecholamine was present in BAT as demonstrated by tyramine- and 1,1-dimethyl-4-phenylpiperazinium iodide- (DMPP) induced depolarization in BAT from normal rats and its absence when BAT from reserpinized rats was used. In BAT from reserpinized rats l-norepinephrine, l-phenylephrine, and l-isoproterenol all similarly depolarized the bronw adipocytes over the concentration range of 10(-8) to 10(-6) M with a maximal depolarization of about 25 mV. Dopamine and d-norepinephrine were more than 100 times less potent. The beta-adrenergic blocker propranolol competitively inhibited isoproterenol-induced depolarization, whereas the alpha-adrenergic blackers, phentolamine and phenoxybenzamine, inhibited the phenylephrine-induced depolarization with much smaller inhibitory effects on the isoproterenol-induced depolarization. Both phenylephrine and isoproterenol elicited transient depolarizations when briefly added to the bathing medium while continuously recording from the same cell. Both the agonist and antagonist studies are interpreted as indicating the presence of both alpha- and beta-adrenergic receptors on BAT cells which mediate catecholamine-induced depolarization.     

Polycyclic musk fragrances in human adipose tissue and human milk

Polycyclic musk fragrances-substituted indane and tetraline derivatives-which are intensively utilized in cosmetics and detergents were determined in a total of 14 human adipose tissue samples and 5 human milk samples by GC/EI/MS in the SIM mode. The residue levels ranged from 16 to 189 micrograms/kg fat for HHCB and from 8 to 58 micrograms/kg fat for AHTN, respectively. In a few samples also ADBI, AHDI and ATII were detected at lower levels. In analogy to the nitro musks, the dermal sorption of these lipophilic compounds from cosmetics and detergents is discussed as a possible contamination route.     

Multihormonal control of ob gene expression and leptin secretion from cultured human visceral adipose tissue: increased responsiveness to glucocorticoids in obesity

The direct role of hormones on leptin synthesis has not yet been studied in cultured adipose cells or tissue from lean and obese subjects. Moreover, this hormonal regulation has never been addressed in human visceral fat, although this site plays a determinant role in obesity-linked disorders. In this study, we investigated the hormonal control of ob expression and leptin production in cultured visceral adipose tissue from lean and obese subjects. We more particularly focused on the interactions between glucocorticoids and insulin. We also briefly tackled the role of cAMP, which is still unknown in man. Visceral (and subcutaneous) adipose tissues from eight obese (body mass index, 41 +/- 2 kg/m2) and nine nonobese (24 +/- 1 kg/m2) subjects were sampled during elective abdominal surgery, and explants were cultured for up to 48 h in MEM. The addition of dexamethasone to the medium increased ob gene expression and leptin secretion in a time-dependent manner. Forty-eight hours after dexamethasone (50 nmol/L) addition, the cumulative integrated ob messenger ribonucleic acid (mRNA) and leptin responses were, respectively, approximately 5- and 4-fold higher in obese than in lean subjects. These responses closely correlated with the body mass index. The stimulatory effect of the glucocorticoid was also concentration dependent (EC50 = approximately 10 nmol/L). Although the maximal response was higher in obese than in lean subjects, the EC50 values were roughly similar in both groups. Unlike dexamethasone, insulin had no direct stimulatory effect on ob gene expression and leptin secretion. Singularly, insulin even inhibited the dexamethasone-induced rise in ob mRNA and leptin release. This inhibition was observed in both lean and obese subjects, whereas the expected stimulation of insulin on glucose metabolism and the accumulation of mRNA species for the insulin-sensitive transporter GLUT4 and glyceraldehyde-3-phosphate dehydrogenase occurred in lean patients only. This inhibitory effect was already detectable at 10 nmol/L insulin and was also observed in subcutaneous fat. Although a lowering of intracellular cAMP concentrations is involved in some of the effects of insulin on adipose tissue, this cannot account for the present finding, because the addition of cAMP to the medium also decreased ob mRNA and leptin secretion (regardless of whether dexamethasone was present). In conclusion, glucocorticoids, at physiological concentrations, stimulated leptin secretion by enhancing the pretranslational machinery in human visceral fat. This effect was more pronounced in obese subjects due to a greater responsiveness of the ob gene and could contribute to the metabolic abnormalities associated with central obesity by para/endocrine actions of hyperleptinemia on adipocytes and liver. Unlike dexamethasone, insulin had no direct stimulatory effect on ob gene expression and leptin secretion, and even prevented the positive response to dexamethasone by a cAMP-independent mechanism that remained functional despite insulin resistance.     

Suppression of fatty acids synthesis in brown adipose tissue of mice fed diets rich in long chain fatty acids

The influence of dietary lipid on fatty acid synthesis in brown adipose tissue has been investigated by feeding different high-fat diets to cold-acclimated mice for a period of 2 weeks. Fatty acid synthesis was measured in vivo with 3H2O, and the fats used in the study were maize oil, beef tallow and medium chain triacylglycerol oil. In the mice fed the maize oil and the beef tallow diets fatty acids synthesis was inhibited in all tissue examined--interscapular brown adipose tissue, epididymal white adipose tissue, the liver and the carcass. Synthesis was more inhibited, however, in brown adipose tissue than in other tissues, and the inhibition was greater on the maize oil diet than on the beef tallow. The medium chain triacylglycerol oil had no inhibitory effect on fatty acid synthesis in any tissue, and hepatic synthesis was even elevated on this diet. It is concluded that fatty acid synthesis in brown adipose tissue, as in other lipogenic tissues, is subject to strong suppression by dietary long chain fatty acids, and particularly by linoleic acid.     

Effect of insulin on triacylglycerol synthesis and secretion by chicken hepatocytes in primary culture

Organophosphates are the most widely used pesticides throughout the world. The considerable amount brought out to the environment poses a risk on the whole population. As organophosphates are neurotoxic substances and their residues can persist in the environment for several weeks, their influence on the nervous system of humans and animals is of principal interest. In the present study, we investigated the alterations induced by dichlorvos, a common pesticide substance, in parameters of somatosensory evoked potentials and hippocampal evoked population spikes of rats. The changes of the cortical vs. hippocampal evoked responses were opposite and only hippocampal effects could be directly explained through an increased cholinergic activity.     

Estrone formation from dehydroepiandrosterone in cultured human breast adipose stromal cells

OBJECTIVE: To describe the phenotype in a family with dominantly inherited cone-rod dystrophy with chromosome assignment to a 19q locus, and to correlate this with current classifications of this retinal dystrophy. DESIGN: A detailed clinical examination including Goldmann perimetry was undertaken in all family members. Six members under the age of 30 years underwent dark-adapted electroretinography, color contrast-sensitivity measurement, dark-adapted static perimetry, and dark adaptometry. PATIENTS: The study included 34 affected and 22 unaffected patients in four generations of a pedigree that manifested autosomal dominant cone-rod retinal dystrophy linked to a chromosome 19q locus by genetic linkage analysis. RESULTS: Loss of visual acuity occurred in the first decade of life, onset of night blindness occurred after 20 years of age, and little visual function remained after the age of 50 years. Central and, later, peripheral retinal fundus changes were associated with central scotoma, pseudoaltitudinal field defects, and finally global loss of function. Psychophysical and electrophysiologic testing before the age of 26 years showed more marked loss of cone than rod function. CONCLUSIONS: The phenotype associated with this mutation does not fit well into previous subtypes of cone-rod dystrophy. Further studies will be needed to correlate specific genetic mutations in this group of conditions with the various clinical phenotypes.