Effects of hyperthyroidism and hypothyroidism on glutamine metabolism by skeletal muscle of the rat.

1. The effects of hyperthyroidism and hypothyroidism on the concentrations of glutamine and other amino acids in the muscle and plasma and on the rates of glutamine and alanine release from incubated isolated stripped soleus muscle of the rat were investigated. 2. Hyperthyroidism decreased the concentration of glutamine in soleus muscle but was without effect on that in the gastrocnemius muscle or in the plasma. Hyperthyroidism also increased markedly the rate of release of glutamine from the incubated soleus muscle. 3. Hypothyroidism decreased the concentrations of glutamine in the gastrocnemius muscle and plasma but was without effect on that in soleus muscle. Hypothyroidism also decreased markedly the rate of glutamine release from the incubated soleus muscle. 4. Thyroid status was found to have marked effects on the rate of glutamine release by skeletal muscle per se, and may be important in the control of this process in both physiological and pathological conditions.     

The configuration of the sesquiterpenoid 4-hydroxy-myoporone (athanagrandione)

The conversion of eremoacetal to (?)-1-(furan-3-yl)-4-hydroxy-4,8-dimethylnonane-1,6-dione establishes the configuration of (?)-4-hydroxymyoporone (athanagrandione) as R.     

The effect of tumour bearing on skeletal muscle glutamine metabolism.

1. The effects of tumour bearing on glutamine metabolism in rat skeletal muscle were examined using the Walker 256 carcinosarcoma. 2. There was a rapid and marked decrease in skeletal muscle glutamine content, which was correlated with the size of the tumour, and a decrease in plasma glutamine concentration. 3. The rate of release of glutamine from EDL muscle in vitro was increased in cachectic, tumour bearing animals, but was unaffected from the soleus muscle of the same animals. 4. It is hypothesized that the increase in the rate of muscle glutamine release during cachexia represents a response of this tissue in order to satisfy the demand for glutamine by the tumour or by cells of the immune system.     

Dilated thin-walled blood and lymphatic vessels in human endometrium: a potential role for VEGF-D in progestin-induced break-through bleeding

Progestins provide safe, effective and cheap options for contraception as well as the treatment of a variety of gynaecological disorders. Episodes of irregular endometrial bleeding or breakthrough bleeding (BTB) are a major unwanted side effect of progestin treatment, such that BTB is the leading cause for discontinued use of an otherwise effective and popular medication. The cellular mechanisms leading to BTB are poorly understood. In this study, we make the novel finding that the large, dilated, thin walled vessels characteristic of human progestin-treated endometrium include both blood and lymphatic vessels. Increased blood and lymphatic vessel diameter are features of VEGF-D action in other tissues and we show by immunolocalisation and Western blotting that stromal cell decidualisation results in a significant increase in VEGF-D protein production, particularly of the proteolytically processed 21 kD form. Using a NOD/scid mouse model with xenografted human endometrium we were able to show that progestin treatment causes decidualisation, VEGF-D production and endometrial vessel dilation. Our results lead to a novel hypothesis to explain BTB, with stromal cell decidualisation rather than progestin treatment per se being the proposed causative event, and VEGF-D being the proposed effector agent.     

Body composition determinants of metabolic phenotypes of obesity in nonobese and obese postmenopausal women

Objective : Although obesity is typically associated with increased cardiovascular risk, a subset of obese individuals display a normal metabolic profile (“metabolically healthy obese,” MHO) and conversely, a subset of nonobese subjects present with obesity‐associated cardiometabolic abnormalities (“metabolically obese nonobese,” MONO). The aim of this cross‐sectional study was to identify the most important body composition determinants of metabolic phenotypes of obesity in nonobese and obese healthy postmenopausal women. Design and Methods : We studied a total of 150 postmenopausal women (age 54 ± 7 years, mean ± 1 SD). Based on a cardiometabolic risk score, nonobese (body mass index [BMI] ≤ 27) and obese women (BMI > 27) were classified into “metabolically healthy” and “unhealthy” phenotypes. Total and regional body composition was assessed with dual‐energy X‐ray absorptiometry (DXA). Results : In both obese and nonobese groups, the “unhealthy” phenotypes were characterized by frequent bodyweight fluctuations, higher biochemical markers of insulin resistance, hepatic steatosis and inflammation, and higher anthropometric and DXA‐derived indices of central adiposity, compared with “healthy” phenotypes. Indices of total adiposity, peripheral fat distribution and lean body mass were not significantly different between “healthy” and “unhealthy” phenotypes. Despite having increased fat mass, MHO women exhibited comparable cardiometabolic parameters with healthy nonobese, and better glucose and lipid levels than MONO. Two DXA‐derived indices, trunk‐to‐legs and abdominal‐to‐gluteofemoral fat ratio were the major independent determinants of the “unhealthy” phenotypes in our cohort. Conclusions : The “metabolically obese phenotype” is associated with bodyweight variability, multiple cardiometabolic abnormalities and an excess of central relative to peripheral fat in postmenopausal women. DXA‐derived centrality ratios can discriminate effectively between metabolic subtypes of obesity in menopause.     

Determination of elastic moduli of thin layers of soft material using the atomic force microscope

We address three problems that limit the use of the atomic force microscope when measuring elastic moduli of soft materials at microscopic scales. The first concerns the use of sharp cantilever tips, which typically induce local strains that far exceed the linear material regime. We show that this problem can be alleviated by using microspheres as probes, and we establish the criteria for their use. The second relates to the common use of the Hertz contact mechanics model, which leads to significant errors when applied to thin samples. We develop novel, simple to use corrections to apply for such cases. Samples that are either bonded or not bonded to a rigid substrate are considered. The third problem concerns the difficulty in establishing when contact occurs on a soft material. We obtain error estimates for the elastic modulus resulting from such uncertainty and discuss the sensitivity of the estimation methods to error in contact point. The theoretical and experimental results are compared to macroscopic measurements on poly(vinyl-alcohol) gels.     

First record of shape Saturnius papernai Overstreet, 1977 in the Black Sea,with a review of the genus shape Saturnius Manter, 1969 (Digenea,Bunocotylidae)

Saturnius papernai Overstreet, 1977 is recorded from the stomach of Mugil cephalus L. (Osteichthyes, Mugilidae) in the Black Sea (a new geographical record) off the southern part of the Bulgarian coast. The species is redescribed and figured on the basis of the Black Sea specimens. Some amendments to the generic diagnosis are proposed concerning the presence of a uterine seminal receptacle and a posterior (third) circular flange. It is proposed that the occurrence of S. papernai is a feature of one of the three shoals of M. cephalus in the Black Sea, i.e. the Balkan shoal. In a zoogeographical analysis, S. papernai is regarded as a Mediterranean immigrant, probably a characteristic element of only the South-Western Faunistic Region of the Black Sea. A review of the genus Saturnius Manter, 1969 is presented.     

Cytochemical and Histochemical Aspects of the Digestive Gland Cells of the Mussel Mytilus galloprovincialis (L.) in Relation to Function

The epithelium of the digestive tubules of the mussel Mytilus galloprovincialis is comprised of two cell types, namely digestive and basophilic cells. In basophilic cells, the secretory granules are beta-glucuronidase immunoreactive, a fact that enhances the hypothesis that beta-glucuronidase is synthesized in basophilic cells. A novel observation at the ultrastructural level is the pinocytic activity associated with the formation of coated pits. This observation constitutes direct evidence for endocytic processes taking place in basophilic cells. The use of cryostat sections from the same digestive tubules reveals, in many instances, a very pronounced neutral lipid accumulation in the same structures giving a positive reaction for N-acetyl-beta-hexosaminidase, indicating the association of those lipids with lysosomes. In some mussels, a high content of lipofuscin was observed in the lysosomes of the digestive cells. In these cases, the lysosomal structures show a limited neutral lipid content, and a weaker N-acetyl-beta-hexosaminidase reaction. In the digestive cells, the carbohydrate content of the lysosomes, and very well-developed canal system in the apical part of cells are discussed in relation to their function.     

Autometallographic localization of heavy metals in resin sections, cryosections and isolated cells of the mussel Mytilus galloprovincialis (L.)

In the present study, autometallography (AMG) has been performed on resin-embedded tissue sections, cryosections, as well as on isolated cells from the digestive gland, the gills and the haemolymph of mussels (Mytilus galloprovincialis) collected from the field. The AMG reaction was more intense in cryosections and isolated cells compared to resin sections. This intense AMG reaction found in cryosections and in isolated cells and the time effectiveness of the procedures enhances their use in a variety of studies, such as biomonitoring, even if small amount of metals are to be detected. In addition, the preparation of isolated cells does not require specific instruments or qualified personnel and, thus, the use of isolated cells is encouraging for AMG applications, although further laboratory investigation is required. On the other hand, the use of resin-embedded tissue sections for AMG applications, even though it is complicated and time consuming, leads to a high preservation of structural morphology and allows the exact localization of metals in discrete cellular compartments.