bluuebunny/crossref_metadata_2025_split huggingface dataset:
Testosterone and leptin in a group of Chinese with and without diabetes
Authors: Ng W. Y. , Lui K. F. , Thai A. C. 
Published: March 2003

Summary Aim: Leptin levels in the overweight and differences between men and women may be confounded by sex hormones in obesity‐related type 2 diabetes. We carried out a study of leptin and testosterone and the effect of diabetes on this relationship in 71 Chinese subjects (51 with type 2 diabetes and 20 healthy non‐diabetics) of whom 32 were overweight (body mass index (b.m.i.) > 25.0 kg/m2). Methods and results: Leptin levels were similar in the diabetic (median 7.4, interquartile range 4.2–10.6 ng ml–1) and non‐diabetic (11.3 (6.0–16.3) ng ml–1) subjects. Testosterone and free testosterone in diabetics and non‐diabetics were similar for both gender. Regardless of diabetes status, testosterone and its free form tend to increase in overweight women and decrease in men. Leptin correlated with testosterone in women with diabetes (Pearson correlation coefficient r = 0.495, p = 0.037) but not in diabetic men. Sixty‐eight per cent of leptin variance was affected by b.m.i, insulin, sex (female) and diabetes status in a regression model that excluded testosterone (total and free). However, testosterone and insulin were predictors of leptin changes in the non‐diabetic subjects. In diabetes, b.m.i., sex (female) and insulin remained as predictors of leptin changes. Conclusions: These results suggest that apart from body adiposity, testosterone also influences leptin levels and that diabetes has a significant effect on this association.
Insulin resistance: an independent risk factor for cardiovascular disease?
Authors: Balkau B. , Eschwège E. 
Published: March 2003

SummarySummary. Population‐based studies have shown that patients with type 2 diabetes have a higher cardiovascular morbidity and mortality and an increased all‐cause mortality compared with non‐diabetic subjects. In non‐diabetic subjects, hyperinsulinaemia not only has been associated with an increased cardiovascular risk, but is also related with a number of other cardiovascular risk factors – hyperglycaemia, hypertension, dyslipidaemia, and a central body fat distribution – that constitute the insulin resistance syndrome and are also characteristic of type 2 diabetes. After 23 years of follow‐up in the Paris Prospective Study, both fasting and 2‐h insulin concentrations were related with all‐cause mortality in a U‐shaped fashion, with low and high concentrations being associated with an increased risk, independently of other risk factors; in contrast, while high insulin levels carried an increased risk for cardiovascular and coronary heart disease mortality, this was not independent of other risk factors.
Time‐course changes in plasma endothelin‐1 and its effects on the mesenteric arterial bed in streptozotocin‐induced diabetic rats
Authors: Makino A. , Kamata K. 
Published: March 2003

Summary Aim: To examine the mechanisms underlying the elevated plasma endothelin‐1 (ET‐1) in diabetes and its vascular effects. Results: Relationships between the plasma ET‐1 level and the levels of other plasma constituents (glucose, cholesterol, and triglyceride) were found in 10‐week streptozotocin (STZ)‐induced diabetic rats. In contrast, at 1 week after the STZ injection only plasma ET‐1 and glucose levels were elevated, suggesting that the hyperglycaemia might trigger the excess production of ET‐1. Incubation with high glucose promoted the release of ET‐1 from the isolated mesenteric arterial bed. In STZ‐induced diabetic rats, the maximum contractile response of the mesenteric arterial bed to ET‐1 was significantly reduced, and the vasoconstriction and vasodilation induced by the ETB‐receptor agonist IRL‐1620 in this bed were significantly impaired. The vascular responses induced by these ET receptor agonists were restored to normal by chronic treatment of diabetic rats with insulin for 7 or 4 weeks. Conclusions: These results suggest: (1) that the marked increase in plasma glucose in STZ‐induced diabetic rats elevates the plasma ET‐1; and (2) that the decreased contractile and vasodilator responses of the mesenteric arterial bed to ET‐1 receptor agonists may be due to desensitization of not only ETA, but also ETB receptors, an effect secondary to the elevation of plasma ET‐1.
Treatment of familial hypertriglyceridaemia with acarbose
Authors: Malaguarnera M. , Giugno I. , Ruello P. , Maugeri D. , Pistone G. 
Published: March 2003

Summary Aim: The evaluation of serum triglyceride levels has played an important role as an independent method for assessing the risk factor for coronary atherosclerosis. Fibrates, nicotinic acid, and omega‐3 polyunsaturated fish oils are the pharmacological tools most used today against hypertriglyceridaemia. Acarbose is a pseudotetrasaccharide of microbial origin which exerts a competitive, selective and reversible inhibition of the intestinal α glucoside‐hydrolase. We evaluated the efficacy and side‐effects of acarbose as a new and alternative drug in the treatment of hypertriglyceridaemia in non‐diabetic patients. Methods: We enrolled 30 non‐diabetic patients (18 men, 12 women; mean age 59.23 ± 6.27 years) without a family history of diabetes mellitus affected by familial hypertriglyceridaemia. The study covered a total period of 6.5 months: half of the patients were on 1.5 months of ‘run in’ diet only followed by 5 months of therapeutic diet plus acarbose; and half were on the therapeutic diet plus placebo. We gave 30 dividable pills to all patients. The administration was as follows: half a pill before lunch and half a pill before dinner while on the ‘run in’ diet. Fifteen patients (group A) took acarbose while the reminder (group B) took a placebo (50 mg of starch); these were distributed randomly and the test was double blind. The 20 weeks of study were divided in five 4‐week periods. Fasting serum concentrations of total cholesterol, triglycerides, HDL‐cholesterol (HDL‐c), LDL‐cholesterol (LDL‐c) and glucose were determined at the starting of the study and after each treatment cycle. Glucose values were determined 2 h after lunch at the beginning of the study and at the end of the first, third and fifth month of treatment. All parameters assessed have been analysed by anova. Results: The serum total cholesterol, LDL‐c levels observed in the two groups did not change during the course of treatment. We observed a noteworthy progressive reduction of mean baseline triglyceride levels until the fourth month (p < 0.05) in acarbose‐treated patients, with an increase in HDL‐c (p < 0.008). Conclusions: We maintain that acarbose may be a useful therapeutic tool in addition to the diet in order to reduce triglyceride serum levels in non‐diabetic patients.
Erythrocyte insulin receptor tyrosine kinase activity is increased in glyburide‐treated patients with type 2 diabetes in good glycaemic control
Authors: Santos R. F. , Nomizo R. , Oliveira E. , Ursich M. , Wajchenberg B. , Reaven G. M. , Azhar S. 
Published: March 2003

Summary Aim: The goal of this study was to test the hypothesis that insulin receptor tyrosine kinase activity of isolated erythrocytes would be greater in glyburide‐treated patients with type 2 diabetes in good glycaemic control (n = 13) than in untreated patients (n = 12) with significant fasting hyperglycaemia. Methods: The two groups were similar in age, sex distribution, and body mass index. By selection, glyburide‐treated patients had significantly (p < 0.001) lower (mean ± s.e.m.) fasting glucose (6.9 ± 0.4 vs. 13.9 ± 0.8 mmol/l) and HbAIC (7.4 ± 0.2 vs. 11.8 ± 0.9%) concentrations. In addition, insulin‐stimulated tyrosine kinase activity was increased in erythrocytes from glyburide ‐treated patients (p < 0.01). Results: Although insulin receptor number was similar in solubilized erythrocytes from the two groups, tyrosine kinase activity per insulin receptor was significantly (p < 0.02) greater in erythrocytes from glyburide‐treated patients with type 2 diabetes. Conclusions: These findings are quite similar to previously published data in metformin‐treated patients. As such, it is suggested that decreases in insulin receptor tyrosine kinase activity may contribute to the loss of insulin sensitivity in hyperglycaemic subjects (glucotoxicity), and that an improvement in glycaemic control, irrespective of how it is achieved, will help rectify this abnormality.
N‐phenacylthiazolium bromide decreases renal and increases urinary advanced glycation end products excretion without ameliorating diabetic nephropathy in C57BL/6 mice
Authors: Schwedler S. B. , Verbeke P. , Bakala H. , Weiss M. F. , Vilar J. , Depreux P. , Fourmaintraux E. , Striker L. J. , Striker G. E. 
Published: March 2003

Summary Aims  Advanced glycation end products (AGE), which form from the non‐enzymatic reaction of proteins and sugars, have been implicated in the pathogenesis of diabetic nephropathy. Recently, a compound [N‐phenacylthiazolium bromide (PTB)] has been described which cleaves α,β‐dicarbonyl compounds. In the present study we used diabetic C57BL/6 mice to determine if PTB altered renal AGE levels and reduced diabetic glomerulosclerosis.Methods  Mice with stable hyperglycaemia induced by streptozotocin were given daily subcutaneous injections of either PTB (10 μg/g) or saline for 12 weeks. Renal‐collagen bound AGE and urinary AGE‐peptides were measured by ELISA using an anti‐AGE‐RNase antibody. Renal collagen‐released Nε(carboxymethyl)lysine (CML) and pentosidine were determined by high pressure liquid chromatography (HPLC). Glomerular lesions (volume and mesangial/total surface area) were evaluated by computer‐assisted image analysis. We determined urinary protein/creatinine ratio as a functional parameter. AGE localization was examined by immunohistochemistry using the anti‐AGE‐RNase antibody.Results  Renal collagen‐bound AGE were decreased and urinary AGE excretion was increased in PTB‐treated diabetic mice. However, collagen‐released CML and pentosidine were similar in both groups. Glomerular histology and morphometric analysis revealed also no differences between PTB‐and saline‐treated diabetic mice. The urinary protein/creatinine ratio was unaffected by PTB‐treatment. AGE staining by anti‐AGE‐RNase antibody was present in Bowman's capsules, glomerular basement membranes and cortical tubules. It was decreased in all structures in PTB‐treated diabetic mice.Conclusion  In summary, PTB decreased renal AGE accumulation but did not ameliorate glomerular lesions or proteinuria. Thus, cleavage of AGE by PTB is not sufficient to prevent development of diabetic nephropathy in C57BL/6 mice.
Insulin‐sensitizing action of rosiglitazone is enhanced by preventing hyperphagia
Authors: Pickavance L. C. , Buckingham R. E. , Wilding J. P. H. 
Published: March 2003

SUMMARY Aim  We investigated whether pair‐feeding to prevent hyperphagia would potentiate the insulin‐sensitizing effect of rosiglitazone in chow‐fed and insulin‐resistant dietary obese rats, and studied the role of leptin and hypothalamic neuropeptide Y as mediators of weight gain during treatment.Methods  Dietary obese and chow‐fed rats (575 ± 10 vs. 536 ± 7 g; p < 0.01) were given rosiglitazone (30 mg/kg p.o.) or vehicle daily for 14 days.Results  Energy intake and weight gain were greater in rosiglitazone‐treated ad‐lib‐fed rats (body weight: chow + 24 ± 2 g, rosiglitazone‐treated + 55 ± 2 g, p < 0.001; dietary obese + 34 ± 2 g, rosiglitazone‐treated + 74 ± 7 g, p < 0.001). Half of each rosiglitazone‐treated group were pair‐fed to vehicle‐treated controls. Rosiglitazone normalized circulating free fatty acids (FFAs) and insulin sensitivity in dietary obese rats (homeostasis model assessment (HOMA): chow‐fed controls, 3.9 ± 0.3; dietary obese controls, 6.7 ± 0.7; rosiglitazone‐treated, ad lib‐fed dietary obese, 4.2 ± 0.5; both p < 0.01). Insulin sensitivity improved further with pair‐feeding (HOMA: 2.9 ± 0.4; p < 0.05 vs. rosiglitazone‐treated, ad lib‐fed dietary obese), despite unchanged FFAs. Qualitatively similar findings were made in chow‐fed rats. Pair‐feeding prevented rosiglitazone‐related weight gain in chow‐fed, but not dietary obese rats (body weight: + 49 ± 5 g, p < 0.001 vs. untreated dietary obese controls). Adipose tissue OB mRNA was elevated in dietary obese rats, reduced 49% (p < 0.01) by rosiglitazone treatment, and further (by 16%) with pair‐feeding (p < 0.0001). Plasma leptin, however, only fell in the pair‐fed group. Hypothalamic neuropeptide Y mRNA was unchanged throughout, suggesting that weight gain associated with high‐dose rosiglitazone treatment is independent of hypothalamic neuropeptide Y.Conclusions  Food restriction potentiates the insulin‐sensitizing effect of rosiglitazone in rats, and this effect is independent of a fall in FFAs.
Site‐specific regulation of oestrogen receptor‐α and ‐β by oestradiol in human adipose tissue
Authors: Anwar A. , McTernan P. G. , Anderson L. A. , Askaa J. , Moody C. G. , Barnett A. H. , Eggo M. C. , Kumar S. 
Published: March 2003

SUMMARY Aim  To examine the expression of oestrogen receptors α and β (ERα and ERβ) and their regulation by 17β‐oestradiol (E2) in stromal cells and adipocytes from human subcutaneous (s.c.) and omental (o.m.) adipose tissue.Methods  Subcutaneous and o.m. abdominal adipose tissues were obtained from 10 women (mean age 63.5 ± 4.8 years; mean weight 75.6 ± 6.7 kg) undergoing elective or cosmetic surgery. Immunohistochemistry and RT‐PCR analysis were used to detect the presence of ERα and ERβ. The regulation of ERα and ERβ by E2 (10−7 M to 10−9 M) was examined using Western immunoblotting analysis in both s.c. and o.m. stromal cells and mature adipocytes cultured in serum‐free, phenol red‐free medium.Results  Immunostaining of s.c. and o.m. adipose tissue showed that the ER subtypes were localized predominantly within the nucleus. Western analysis demonstrated that E2 treatments differentially altered ERα and ERβ expression in s.c. and o.m. adipocytes. In s.c. and o.m. stromal cells, E2 (10−8 M) produced a significant up regulation relative to control of 66 kDa ERα (s.c.:1.87 ± 0.22; o.m.:1.97 ± 0.17; p < 0.05) and 60 kDa ERβ (s.c.:1.66 ± 0.3; o.m.: 1.68 ± 0.16; p < 0.05). In s.c. adipocytes, however, ERα expression significantly decreased with E2 10−8 M relative to control while ERβ expression increased (ERα 0.58 ± 0.06, ERβ: 1.47 ± 0.11; p < 0.05). In o.m. adipocytes, the inhibition of ERα with E2 was not observed (ERα 1.86 ± 0.36, ERβ:1.03 ± 0.15, p < 0.05)Conclusions  ERα and ERβ are expressed but differentially regulated by E2 in s.c. and o.m. adipocytes and stromal cells. The upregulation of ERβ by E2 suggests that E2 maintains the expression of these receptors. The feed‐back inhibition of ERα expression by E2 in s.c. but not o.m. adipocytes observed in vitro is consistent with the data from ERα knock out mice where s.c. fat is increased. Selective ER modulators may have different effects in different adipose sites.
Blood glucose‐ and triglyceride‐lowering effect of trans‐dehydrocrotonin, a diterpene from Croton cajucara Benth., in rats
Authors: Silva R. M. , Santos F. A. , Rao V. S. N. , Maciel M. A. , Pinto A. C. 
Published: March 2003

Aim: The objective of this study was to assess in rats the antidiabetic effects (i.e. reduction of hyperglycaemia and hypertriglyceridaemia) of trans‐dehydrocrotonin (t‐DCTN), a bioactive diterpene isolated from the popular medicinal plant Croton cajucara.Methods: Hyperglycaemia was induced by intraperitoneal injection of streptozotocin (STZ) and hypertriglyceridaemia by oral administration of ethanol in rats. The blood glucose levels were measured by the glucose oxidase method using commercially available enzyme kits.Results: Treating rats with t‐DCTN (50 mg/kg) significantly reduced STZ‐induced increases in blood glucose levels as well as ethanol‐induced increases in blood triglycerides.Conclusion: The results suggest that t‐DCTN has an antidiabetic potential that warrants further research on its mechanism and clinical significance.
Cell surface glycoconjugates in the olfactory system of lungfish Protopterus annectens Owen
Authors: Franceschini Valeria , Lazzari Maurizio , Ciani Franco 
Published: March 2003

AbstractFranceschini, V. Lazzari, M. and Ciani, F. 2000. Cell surface glycoconjugates in the olfactory system of lungfish Protopterus annectens Owen. —Acta Zoologica (Stockholm) 81: 131–137Lectin binding was performed on the olfactory system of lungfish Protopterus annectens to identify specific glycoconjugates on the cell surface of olfactory receptor cells. The lectin histochemical patterns and the Western blot analysis indicate that the receptor cells of the olfactory mucosa are characterized by high density of α‐N‐acetyl‐
d‐galactosamine residues on the saccharidic chains of the surface glycoproteins. Other lectins display a regional pattern between the regions of the olfactory bulbs. This different histochemical lectin pattern might be due to a different regional segregation of the olfactory projections. On the other hand it could allow the identification of an area corresponding to the accessory olfactory bulb of terrestrial vertebrates in the ventrolateral region of Protopterus olfactory bulb. The presence in the dipnoan olfactory system of a vomeronasal organ homologous to the organ in amphibians is discussed. Moreover, the selective lectin binding on the surface of primary olfactory neurones suggests that specific cell surface glycoproteins may have a role in the axonal growth due to the continuous cycle of proliferation and the death of olfactory receptor cells.
Circulatory organs of abdominal appendages in primitive insects (Hexapoda: Archaeognatha, Zygentoma and Ephemeroptera)
Authors: Gereben‐Krenn Barbara‐Amina , Pass Günther 
Published: March 2003

AbstractThe abdominal circulatory organs and the haemolymph supply of the terminal filament and the cerci were investigated in a total of nine species (serial semithin sections, TEM, in vivo observations).In all investigated species, the dorsal vessel features a bidirectional flow. In the 10th abdominal segment, there is an intracardiac valve preventing flow in the anterior direction. The posterior portion of the dorsal vessel differs significantly from the anterior portion in design and wall structure. Pumping actions and frequencies do not correspond with each other in the two portions.Vessels supply haemolymph to the long terminal appendages. The terminal filament vessel is connected to the dorsal vessel, the two cercal vessels originate from a transverse septum at the base of the terminal filament. All taxa show the same flow pattern through the caudal appendages. Ephemeroptera have a unique spherical body at the posterior end of the dorsal vessel functioning as a backflow valve.The results indicate that the plesiomorphic state of the circulatory organs in the abdomen of primitive insects differ distinctly from that of higher insects which serve as bases for generalized schemes common to entomological textbooks.
Phylogenetic analysis of the pearlfish tribe Carapini (Pisces: Carapidae)
Authors: Parmentier E. , Castillo G. , Chardon M. , Vandewalle P. 
Published: March 2003

AbstractFishes of the tribe Carapini (Encheliophis and Carapus) share a noteworthy peculiarity: they shelter in holothurian echinoderms or bivalve hosts. Some species are considered parasitic, others commensal. This study focuses on the phylogeny of the tribe, using two other Carapidae species as an outgroup (Snyderidia canina and Onuxodon fowleri). Insofar as possible, the selected anatomical and behavioural characters where chosen in an ecomorphological perspective, as features that could be responses to various lifestyle‐related constraints. Our character selection also took into account the fact that some features are (presumably) linked. Such features were grouped together as a single trait to avoid their overvaluation.This methodology enabled commensals to be separated from parasites, the former belonging to Carapus and the latter to Encheliophis. Carapus species reflect in their morphology the constraints imposed by a diet of hard, mobile, elusive prey, showing predator‐type features: a strong dentition, a wide mouth opening, a robust food intake apparatus. On the other hand, the endoparasitic Encheliophis species show a generally weaker buccal apparatus and narrow mouth opening, in relation to the different constraints of their lifestyle where the diet constraints are less pronounced: they eat body parts of their host. Changes in both generic diagnoses are proposed and three species are transferred from Encheliophis to Carapus.
Scale morphogenesis and ultrastructure of dermis during embryonic development in the alligator (Alligator mississippiensis, Crocodilia, Reptilia)
Authors: Alibardi L. , Thompson M. B. 
Published: March 2003

AbstractFormation of scales in different body regions of embryonic alligators is described using light and electron microscopy. Transformation of the skin surface to produce scales takes place between stages 19 and 23, after which the shape of scales is complete over most of the embryonic surface. Scalation is not synchronous; different regions develop scales at different rates. Initially scales are formed on the back and dorsal side of the proximal tail and appear as undulations of the epidermis which form symmetrical (bumps) or asymmetrical (serrated) scale anlagen. No dermal condensations are apparent beneath the epidermis, although in some areas of the skin (belly, limbs) mesenchymal cells are more numerous within the bumps than in other areas. At stage 21, scalation has spread to the neck and belly but is absent or poorly developed over most areas of the flank, gular, jaw, limb and head regions. Grooves form between the outer edges of adjacent scales or interbump regions. A superficial denser dermis and a reticulated deep subdermis are visible in many scales from stage 21. The dermis forms a superficial loose and a deep dense layer from stage 22. Both loose and deep dermis, and sometimes the deep reticulate subdermis, move towards the surface to form the dermal core of scales, although the mechanism of this movement is not known. Bundles of collagen fibrils, with almost no elastic fibrils, are progressively deposited, especially in the denser dermis. At stage 22, the flank, gular and proximal areas of limbs form scales, but the head, jaw, distal limbs and digits still lack scales. The digits become scaled at stage 23 when scalation is well advanced in the other regions. By stage 24 most of the body is scaled and subsequent scale modifications occur only by growth. Five main types of scales are recognized by their shape: symmetrical scutes, asymmetrical scutes, overlapping scutes, tuberculate scales, and elevated asymmetrical scutes (tail verticils). Pigmentation, mainly due to epidermal melanocytes, is visible at embryonic stage 23 and progresses through stages 24 and 25.