Optical parameters of embedded abnormalities in tissues as determined by Monte Carlo simulation

Photon propagation through tissue phantoms, made of heart, adipose, and spleen tissues was simulated by Monte Carlo procedure. To detect the presence of deep-seated abnormalities, phantoms of heart with adipose and spleen tissues embedded into it were created and simulations were performed to scan the tissue surface with a source and four detector model. Profiles drawn showed variation in parameters such as backscattered intensity in regions where adipose and spleen tissues were embedded. This study shows that depending on the type of embedded tissue the backscattered fraction as measured at 2?mm from the input fiber is altered. This is enhanced for adipose and decreased for spleen tissue. This is not only shown in scanned profiles on the surface but also in constructed images.     

Development of biological tissue-equivalent phantoms for optical imaging

Optical characteristics of freshly isolated tissues depend on their color and composition. The surface backscattered profile, which account for the tissue compositional variation in fresh excised sheep's heart, lungs, bone and muscle, were measured by multi-probe reflectometer. Optical phantoms were prepared from paraffin wax by mixing a specific combination of wax color materials till the surface backscattered profile of these matched with that of the biological tissues. The optical parameters absorption coefficient (micro(a)), reduced scattering coefficient (micro(s)) and anisotropy factor (g) of these phantoms, are the same as that of biological tissues and are obtained by matching their surface backscattered profiles with that as simulated by Monte Carlo procedure. The maximum and minimum values of absorption coefficient are for the phantoms of lungs (1.0 cm(-1)) and muscle (0.02 cm(-1)), whereas, for scattering coefficient these values are for muscle (21.2 cm(-1)) and bone (13.08 cm(-1)).     

Immunohistochemical localization of irisin in mole rats (Spalax leucodon)

Irisin was first identified in skeletal muscle cells. It is an exercise protein that is secreted into the circulation; it causes conversion of white adipose tissue to brown adipose tissue. We investigated irisin immunoreactivity in mole rat (Spalax leucodon) tissues. We examined cerebellum, pituitary, heart, liver, pancreas, spleen, uterus, kidney and striated muscle in female adult mole rats. Tissues were processed, embedded in paraffin, sectioned at 5 μm and stained immunohistochemically for irisin. Irisin immunostaining was detected in the cytoplasm of stained cells; the cytoplasm of Purkinje cells was unstained. We found that irisin may be synthesized in many tissues. The function of locally synthesized irisin currently is unknown.     

Placental transfer of halogenated benzenes (pentachloro-, pentachloronitro-, and hexabromo-) in rats.

The present study was carried out to provide information on the placental transfer of three organohalogens of environmental concern. Pentachloro-, pentachloronitro-, and hexabromobenzene were administered per os to rats daily on days 6 through 15 of gestation at level of 40, 100, and 200 mg/kg body weight. On day 22, the dams were killed and fetuses removed by caesarean section. Maternal brain, heart, kidney, liver, spleen and adipose tissue as well as whole fetus, fetal liver and fetal brain were analyzed for organohalogen residue by GLC. Pentachlorobenzene accumulated in the fetus to a greater extent than hexabromobenzene. In maternal tissues pentachlorobenzene accumulated to the greatest extent in adipose tissue, followed by liver, spleen, brain, heart and kidney. With hexabromobenzene, the greatest accumulation was observed in adipose tissue, followed by spleen, liver, heart, kidney and brain. Pentachloronitrobenzene was not detected (0.05 p.p.m.) in any maternal or fetal tissue.     

Short-term handling of the slimming agent oleoyl-estrone in liposomes (Merlin-2) by the rat

Female adult rats were injected in the jugular vein with oleoyl-³H-estrone incorporated into liposomes. The label rapidly disappeared from the blood, being taken up by the tissues, mainly liver, spleen and lung, which filtered most of the label. However, many other tissues, such as the heart, brown adipose tissue, adrenals and visceral fat incorporated significant amounts of oleoyl-estrone. The analysis of the form in which the label remained 10 min after the injection showed that it was hydrolysed in a large proportion even in liver and lungs. However, in most tissues (brain, brown and white - periovaric - adipose tissues and ovaries), intact oleoyl-estrone accounted for less than one quarter of all tissue label, and less than 10% in the case of subcutaneous adipose tissue and uterus. This rapid destruction of oleoyl-estrone is in agreement with the active role of this compound in the control of body weight.     

Molecular cloning and expression of bovine (Bos taurus) leptin receptor isoform mRNAs

We characterized Bos taurus leptin receptor (Ob-R) isoform mRNAs as well as their expression in different tissues, including some adipose depots (perirenal, subcutaneous and intermuscular adipose tissues). Based on the GenBank database sequences of the bovine partial Ob-R, primers were designed to amplify cDNAs of bovine Ob-R isoforms. The full-length cDNAs of bovine the Ob-R isoforms were cloned by combination with 3'-and 5'-RACE. Three bovine Ob-R isoform cDNAs were cloned and the sequence analyses revealed that these cDNAs were bovine Ob-R isoforms, i.e., the long form (Ob-Rb), the middle form (Ob-Ra) and the short form (Ob-Rc). The open reading frames of Ob-Ra, Ob-Rb and Ob-Rc gene were 2688, 3498 and 2673 bp, respectively. The deduced amino acid sequences suggested that the isoforms were single transmembrane proteins, and differed in the C-terminal amino acid sequences. The amino acid sequence of these bovine Ob-R isoforms showed 73-75% identity compared with the corresponding mouse isoforms. The tissue-specific expression of the bovine Ob-R isoforms were measured by semi-quantitative RT-PCR. Expression of Ob-Rb was highest in liver, heart, spleen and kidney, with lower expression in lung and testis, and slight expression in muscle. Ob-Ra was highly expressed in liver and spleen, whereas moderate expression was observed in heart, testis, and muscle, and its expression was the lowest in lung and kidney. Ob-Rc mRNA was expressed in the liver, heart, testis, kidney and muscle, but not in the lung and spleen. In adipose tissues, higher expression of Ob-Ra and Ob-Rb mRNA was observed in intermuscular adipose tissue than in subcutaneous or perirenal adipose tissues. Ob-Ra mRNA level was positively correlated with Ob-Rb mRNA level in the adipose tissues (r=0.81, P<0.05). The results demonstrated that each Ob-R isoform mRNA was differentially expressed in various tissues of cattle, which may be involved in the difference of peripheral actions for leptin.     

Fatty acid composition of liver, adipose tissue, spleen, and heart of mice fed diets containing t10, c12-, and c9, t11-conjugated linoleic acid

Conjugated linoleic acid (CLA) isomers have unique effects on tissue lipids. Here we investigated the influence of individual CLA isomers on the lipid weight and fatty acid composition of lipid metabolizing (i.e. liver and retroperitoneal adipose) and lipid sensitive (i.e. spleen and heart) tissues. Female mice (8 week old; n=6/group) were fed either a control or one of the two CLA isomer supplemented (0.5%) diets for 8 weeks. The cis-9, trans-11-CLA diet reduced the 18:1n-9 wt% by 20-50% in liver, adipose tissue, and spleen, reduced the spleen n-3 polyunsaturated fatty acid (PUFA) by 90%, and increased the n-6 PUFA wt% by 20-50% in all tissues except heart. The trans-10, cis-12-CLA reduced both the n-6 and n-3 PUFA wt% in liver (>50%), reduced the heart n-3 PUFA wt% by 25%, and increased the wt% of spleen n-3 PUFA by 700%. The functional consequences of such changes in tissue fatty acid composition need to be investigated.     

Existence of uncoupling protein-2 antigen in isolated mitochondria from various tissues.

Antibodies against Escherichia coli-expressed uncoupling protein-2 (UCP2) and uncoupling protein-3 (UCP3) were raised by operating the blotted proteins into the spleen of minipigs. The antisera reacted more intensively with the recombinant UCP2 and UCP3 than with uncoupling protein-1 (UCP1) isolated from brown adipose tissue. Moreover, anti-UCP2 and cross-reacting anti-UCP3 antibodies identified the presence of the UCP2/3 antigen in isolated mitochondria from rat heart, rat kidney, rat brain, rabbit epididymal white adipose tissue, hamster brown adipose tissue, and rabbit skeletal muscle. It has been concluded that UCP2 is expressed in these tissues (UCP3 in skeletal muscle); however their existence in mitochondria had not previously been demonstrated.     

Localization and characterization of tissue changes by laser backscattering imaging and Monte Carlo simulation

Laser backscattering from biological tissues depends on their composition and blood flow. The onset of the tissue abnormalities is associated with the change in composition at a specific location which may affect laser backscattering. The objective of the present work is to detect the compositional changes in tissue-equivalent phantom of fat, prepared by mixing paraffin wax with wax colors, and to characterize these in terms of their optical parameters. For this purpose these phantoms are scanned by a multi-probe non-contact automatic laser scanning system and images of the normalized backscattered intensity (NBI) are constructed. By scanning the background subtracted image of the phantom the location of the abnormality and its size from the full width at half maximum (FWHM) are determined. The data obtained by ultrasonic technique for localization of the abnormalities are in agreement with that as obtained by the present method. The optical parameters of the abnormality are obtained by matching the measured surface profiles of the abnormality with that of the profile obtained by Monte Carlo simulation. This analysis shows the possibility of detection of changes at the onset stage in tissues as required for planning of the photodynamic therapy.     

Genome-wide profiling of gene expression in 29 normal human tissues with a cDNA microarray.

We have performed a comprehensive analysis of the expression profiles in 25 adult and 4 fetal human tissues by means of a cDNA microarray consisting of 23,040 human genes. This study revealed a number of genes that were expressed specifically in each of those tissues. Among the 29 tissues examined, 4,080 genes were highly expressed (at least a five-fold expression ratio) in one or only a few tissues and 1,163 of those were expressed exclusively (more than a ten-fold higher expression ratio) in a particular tissue. Expression of some of the genes in the latter category was confirmed by northern analysis. A hierarchical clustering analysis of gene-expression profiles in nerve tissues (adult brain, fetal brain, and spinal cord), lymphoid tissues (bone marrow, thymus, spleen, and lymph node), muscle tissues (heart and skeletal muscle), or adipose tissues (mesenteric adipose and mammary gland) identified a set of genes that were commonly expressed among related tissues. These data should provide useful information for medical research, especially for efforts to identify tissue-specific molecules as potential targets of novel drugs to treat human diseases.     

Organ specific regulation of malic enzyme and hexosemonophosphate shunt dehydrogenases activity by high carbohydrate diet

The effect of starvation-refeeding transitions on the activity of malic enzyme and hexosemonophosphate shunt dehydrogenases in lipogenic and non-lipogenic tissues from rats was investigated. Starvation of the rats caused a decrease of malic enzyme activity in the liver, white and brown adipose tissue. Refeeding of the animals with high carbohydrate diet caused a several fold increase of malic enzyme activity in these tissues. Substitution of high fat for high carbohydrate diet resulted in only a slight increase of malic enzyme activity in the liver, white and brown adipose tissues. In the same rats, no significant effect of starvation-refeeding transition on malic enzyme activity in the kidney cortex, brain, heart, skeletal muscle and spleen was observed. The changes of the activity of hexosemonophosphate shunt dehydrogenases during starvation-refeeding transition essentially paralleled those of malic enzyme in all the tissues examined.     

Increased rates of fatty acid uptake and plasmalemmal fatty acid transporters in obese Zucker rats

Giant vesicles were used to study the rates of uptake of long-chain fatty acids by heart, skeletal muscle, and adipose tissue of obese and lean Zucker rats. With obesity there was an increase in vesicular fatty acid uptake of 1.8-fold in heart, muscle and adipose tissue. In some tissues only fatty acid translocase (FAT) mRNA (heart, +37%; adipose, +80%) and fatty acid-binding protein (FABPpm) mRNA (heart, +148%; adipose, +196%) were increased. At the protein level FABPpm expression was not changed in any tissues except muscle (+14%), and FAT/CD36 protein content was altered slightly in adipose tissue (+26%). In marked contrast, the plasma membrane FAT/CD36 protein was increased in heart (+60%), muscle (+80%), and adipose tissue (+50%). The plasma membrane FABPpm was altered only in heart (+50%) and adipose tissues (+70%). Thus, in obesity, alterations in fatty acid transport in metabolically important tissues are not associated with changes in fatty acid transporter mRNAs or altered fatty acid transport protein expression but with their increased abundance at the plasma membrane. We speculate that in obesity fatty acid transporters are relocated from an intracellular pool to the plasma membrane in heart, muscle, and adipose tissues.     

Sulphation of contraceptive steroids

The sulphation of a number of contraceptive steroids by rabbit tissue in vitro was investigated. With liver tissue the three synthetic gestagens (norethisterone, norgesterel and lynestrenol) were sulphated at different rates and none was sulphated as rapidly as dehydroepiandrosterone; sulphation occurred at the tertiary 17 beta-hydroxyl group. The synthetic oestrogen ethynyloestradiol was sulphated more rapidly than dehydroepiandrosterone, both mono and disulphates being formed. Of the other tissues studied, sulphation occurred with stomach and lung but not with heart, spleen, muscle, kidney or adipose tissue. These in vitro studies provide confirmation of in vivo findings regarding sulphate conjugates of the synthetic steroids.     

Comparative utilization in vivo of [U-14C] glycerol, [2-3H] glycerol, [U-14C] glucose and [1-C14] palmitate in the rat

Female rats were injected i.v. with comparable trace amounts of [U-14C] glycerol, [2-3H] glycerol, [U-14C] glucose, or [1-14C] palmitate, and killed 30 min afterwards. The radioactivity remaining in plasma at that time was maximal in animals receiving [U-14C] glucose while the appearance of radioactive lipids was higher in the [U-14C] glycerol animals than in other groups receiving hydrosoluble substrates. The carcass, more than the liver, was the tissue where the greatest proportion of radioactivity was recovered, while the greatest percentage of radioactivity appeared in the liver in the form of lipids. The values of total radioactivity found in different tissues were very similar when using either labelled glucose or glycerol but the amount recovered as lipids was much greater in the latter. The maximal proportion of radioactive lipids appeared in the fatty-acid form in the liver, carcass, and lumbar fat pads when using [U-14C] glycerol as a hydrosoluble substrate, and the highest lipidic fraction appeared in adipose tissue as labelled, esterified fatty acids. In the spleen, heart, and kidney, most of the lipidic radioactivity from any of the hydrosoluble substrates appeared as glyceride glycerol. The highest proportion of radioactivity from [1-14C] palmitate appeared in the esterified fatty acid in adipose tissue, being followed in decreasing proportion by the heart, carcass, liver, kidney, and spleen. Thus at least in part, both labelled glucose and glycerol are used throughout different routes for their conversion in vivo to lipids. A certain proportion of glycerol is directly utilized by adipose tissue. The fatty acids esterification ability differs among the tissues and does not correspond directly with the reported activities of glycerokinase, suggesting that the alpha-glycerophosphate for esterification comes mainly from glucose and not from glycerol.     

A juxtarenal myelolipoma in a cottontop marmoset (Saguinus oedipus): A case report

A myelolipoma was surgically removed from the abdomen of a 15-year-old female cottontop marmoset (Saguinus oedipus). Because of its close adherence to the right kidney, a unilateral nephrectomy was performed. The post-surgical recovery was uneventful. A myelolipoma is a circumscribed mass of bone marrow elements embedded in mature adipose tissue. These masses have been reported in the adrenal glands, paravertebral tissue, intrathoracic tissues, and mesentery of man. A similar condition has been observed in the liver and spleen of both captive and wild felidae. This report documents the first observation of this tumor-like condition in nonhuman primates with the possible exception of a subcutaneous myeloliposarcoma in a potto.     

Distribution and quantification of β-3 adrenergic receptor in tissues of sheep

The β-3 adrenergic receptor (ADRB3) is a G-protein coupled receptor involved in regulating lipolysis, as part of homeostatic regulation. In this study, South African Mutton Merino and Shanxi Dam Line were used to study the distribution and quantification of ADRB3 in adipose (subcutaneous, omental, retroperitoneal, mesenteric and perirenal fat) and non-adipose (heart, liver, spleen, lung and kidney) tissues of sheep. The protein was determined by immunohistochemical technique and by mRNA abundance via real-time polymerase chain reaction. ADRB3 was detected in all studied tissues with abundance in adipose tissues higher than in non-adipose tissues (P < 0.001). For adipose tissues, greater expression was found in deep deposits such as great omental and retroperitoneal fat than in subcutaneous fat (P < 0.05). Significant differences (P < 0.05) both for mRNA and for protein expression also existed between the two sheep flocks. These findings are consistent with the known function of ADRB3 in mediating lipolysis and homeostasis in adipose tissues.     

猪雌激素受体关联受体a基因的克隆、表达及其对脂肪细胞脂质聚集的影响

雌激素受体关联受体α(Estrogen-related receptor α,ERRα)是调控机体能量代谢的关键转录调控因子,其在白色脂肪组织中的作用尚不清楚。本研究旨在通过touch down-PCR方法克隆猪ERRα基因的ORF序列;通过Western blotting和细胞免疫荧光染色法分析其在猪各组织及成熟脂肪细胞中的表达模式;利用ERRα特异性抑制剂XCT790处理原代培养的猪成熟脂肪细胞,探讨其对成熟脂肪细胞甘油三酯聚集的影响。结果显示,所克隆的猪ERRα基因ORF序列长1269bp(GenBank Accession No.FJ446485,尚未公布),编码422个氨基酸,其核苷酸和氨基酸序列与其他物种高度同源;ERRα蛋白高表达于猪白色脂肪组织(White adipose tissue,WAT)、肾脏以及心脏中,在脾脏中表达量较低;细胞免疫荧光化学染色显示,ERRα蛋白广泛分布于脂肪细胞的细胞核和胞浆中;XCT790在10μmol/L浓度时显著抑制了ERRα蛋白的表达和成熟脂肪细胞中甘油三酯的聚集。本研究将为有效调控体脂沉积提供新的靶点和理论参考。     

Distribution of superoxide dismutase in the ground squirrel (Citellus citellus): effect of the hibernation and arousal

The activity of superoxide dismutase (SOD) was studied in the liver, kidney, interscapular brown adipose tissue (IBAT), lung, heart and spleen of the active and hibernating ground squirrel (Citellus citellus). One group was examined immediately after the arousal from the hibernation. A considerable activity of this enzyme was found in homogenates of all tissues studied except the lung. This activity was lower in the liver and lung of the ground squirrel than in the rat (P less than 0.01). In the other tissues studied the enzyme activity was about the same level in both animals. In the ground squirrel hibernation didn't produce the significant change in SOD activity, as compared with the active state, except in the spleen. Tested immediately after the arousal, SOD activity was significantly higher in all tissues studied except in the IBAT, as compared with the hibernating ones (P less than 0.01).     

Mammalian adipose tissue and muscle are major sources of lipid transfer protein mRNA

The plasma cholesteryl ester transfer protein (CETP) catalyzes the transfer of cholesteryl esters from high density lipoproteins (HDL) to triglyceride-rich lipoproteins and plays a major role in the catabolism of HDL. Lipoprotein lipase (LPL) is the rate-limiting enzyme for hydrolysis of circulating triglyceride and is involved in HDL formation. We show that tissues containing LPL are major sources of CETP mRNA in several mammalian species, including some with low cholesteryl ester transfer activity in plasma. In hamsters, adipose tissue and heart were found to be the richest sources of both CETP and LPL mRNA; in situ hybridization studies showed that the same cell types (i.e. adipocytes or myocytes) contained CETP and LPL mRNA in these tissues. Isolated adipocytes synthesized active CETP. Dietary studies revealed a complex pattern of response of CETP mRNA levels in different tissues, which showed partial similarity to the changes in LPL mRNA abundance. However, high cholesterol diets resulted in increased CETP mRNA abundance in adipose tissue, heart, and skeletal muscle, without equivalent changes in LPL mRNA. Plasma HDL cholesteryl ester levels showed strong inverse correlations with CETP mRNA abundance in adipose tissue. The results suggest a conserved function of CETP in adipose tissue and heart, such as a co-ordinate action with LPL to enhance HDL turnover. Although there is considerable overlap in the tissue- and cell-specific pattern of CETP and LPL gene expression, dietary studies revealed only limited parallelism in response at the mRNA level. The increase in CETP mRNA in peripheral tissues in response to increased dietary cholesterol suggests that local induction of CETP synthesis may help to recycle cholesterol deposited in these tissues during lipolysis of dietary lipoproteins.     

Lipoprotein lipase: size of the functional unit determined by radiation inactivation

Radiation inactivation was used to determine the functional molecular weight of lipoprotein lipase (LPL) in rat heart and adipose tissues. This technique reveals the size of the smallest unit required to carry out the enzyme function. Supernatant fractions of the tissue homogenates were exposed to high energy electrons at -135 degrees C. LPL activity showed a simple exponential decay in all samples tested. Because changes in nutritional state shift the distribution of LPL between the capillary endothelial and parenchymal cells within heart and adipose tissues, fasted and refed rats were used for the radiation studies. The functional molecular weight was calculated to be 127,000 +/- 15,000 (mean +/- SD) daltons for heart and adipose. Thus, the smallest unit required for enzyme function was the same in both of these tissues and did not vary with nutritional state. The data suggest that, compared with LPL monomer sizes reported in the range 55,000 to 72,000, this active unit constitutes a dimer.