Complete characterization of the DQB1 first exon polymorphism

Here we report an additional source of variation resulting from genetic polymorphism in HLA-DQbeta1 genes, namely, allelic diversity in the first exon of the HLA-DQB1 locus, which encodes the leader peptide sequence. Six different variants, including a novel polymorphic site, were detected among the DBQ1 haplotypes.

Inspiratory neural drive response to hypoxia adequately estimates peripheral chemosensitivity in OSAHS patients

The aim of the present study was to examine the relationships between the responses to progressive isocapnic hypoxia and hypoxic withdrawal test in patients with obstructive sleep apnoea-hypopnoea syndrome (OSAHS) and to analyse the determinants of carotid body sensitivity in OSAHS. Nineteen consecutive OSAHS patients and 13 healthy subjects were selected. Ventilatory (delta V'I/Sa,O2/BSA) and inspiratory neural drive (delta P0.1/Sa,O2) responses to progressive isocapnic hypoxia were determined. Peripheral chemosensitivity was evaluated by the hypoxic withdrawal test, which measures the decrease in ventilation caused by two breaths of 100% oxygen (%delta V'I). Withdrawal response and ventilatory and inspiratory neural drive responses to hypoxia were lower in OSAHS patients than in control subjects. In patients with OSAHS, %delta V'I correlated significantly with delta V'I/Sa,O2/BSA and with delta P0.1/Sa,O2. On stepwise multiple linear regression analysis, a strong correlation between %delta V'I and delta P0.1/Sa,O2 was found. Moreover, %delta V'I, delta V'I/Sa,O2/BSA and delta P0.1/Sa,O2 were significantly correlated with minimum arterial oxygen saturation and with arousal index. Obstructive sleep apnoea-hypopnoea syndrome patients have a strong relationship between peripheral chemosensitivity and respiratory response to hypoxia, suggesting that hypoxic stimulation of central chemoreceptors is minimally relevant in obstructive sleep apnoea-hypopnoea syndrome. Moreover, sensitivity of the carotid body in patients with obstructive sleep apnoea-hypopnoea syndrome is related to sleep disruption and to nocturnal hypoxia.

Improved reperfusion and clinical outcome with enoxaparin as an adjunct to streptokinase thrombolysis in acute myocardial infarction. The AMI-SK study

AIMS

To establish whether the addition of enoxaparin (a low-molecular-weight heparin) to streptokinase therapy improves early and sustained coronary patency and clinical outcome in patients with evolving myocardial infarction.

METHODS AND RESULTS

A total of 496 patients with acute myocardial infarction treated with streptokinase were randomized to an intravenous bolus (30 mg) and subcutaneous injections (1mg x kg(-1), twice daily) of enoxaparin (n=253), or placebo (n=243) for 3-8 days. The median duration of treatment in both groups was 5 days. ST-segment resolution at 90 min and 180 min measured by electrocardiogram was improved in patients receiving enoxaparin. Complete, partial and no ST-segment resolution at 180 min was observed in 36%, 44% and 19% in the enoxaparin group vs 25%, 44% and 31% in the placebo group, respectively (P=0.004). Assessment of the primary end-point revealed improved TIMI-3 flow with enoxaparin vs placebo (70% vs 58%, P=0.01). Combined TIMI-2 and -3 flow was also improved (88% vs 72%, P=0.001), as was TIMI frame count (P=0.003). The triple clinical end-point of death, reinfarction and recurrent angina at 30 days was reduced with enoxaparin (13% vs 21%, P=0.03).

CONCLUSION

Streptokinase in combination with enoxaparin is associated with better ST-segment resolution and better angiographic patency at days 5-10, suggesting more effective reperfusion. This was associated with a significant reduction in clinical events, indicating less reocclusion.

Effects of pregnancy on insulin receptor in liver, skeletal muscle and adipose tissue of rats

The mechanism responsible for insulin resistance during pregnancy remains unclear. Considerable evidence indicates that the insulin receptor plays an important role in insulin sensitivity. It seems possible that the hormonal milieu during gestation could have an effect on the insulin receptor. In the present study, measurements of tyrosine phosphorylation and protein content of the insulin receptor and expression of its gene in liver, skeletal muscle and adipose tissue indicate that during pregnancy significant changes occur in these parameters. We found that at the end of early gestation (day 10), muscle and adipose tissue are very sensitive to insulin action because the amount, phosphorylation and gene expression of insulin receptor is higher than in late gestation (days 15-20), while the tissue which is most sensitive to insulin action in late gestation is the liver. Our hypothesis is that these results are connected with changes in the concentrations of estradiol and progesterone observed during pregnancy. In conclusion, our previous and present findings seem to demonstrate that the different concentrations of gestational hormones play an important role in insulin sensitivity in this period and that each tissue responds in the most appropriate manner to guarantee the gestation in its entirety.

[Parathyroid cyst. Report of one case]

Parathyroid cysts are rare in clinical practical. We report of 33 years old woman, with a cystic lesion in the right lobe of thyroid. The content of the cyst obtained through needle aspiration, showed a high PTH concentration (parathyroidhormone). The patient underwent surgery and the cyst was removed. The anatomopathological diagnosis was a parathyroid cyst.

IgE-mediated anaphylaxis to Thiomucase, a mucopolyssacharidase: allergens and cross-reactivity

BACKGROUND

Thiomucase is a mucopolysaccharidase obtained from ovine tissues mainly used to facilitate the diffusion of local anaesthetics and in the treatment of cellulitis. A patient with an anaphylaxis in relation to the intramuscular administration of Thiomucase is reported.

OBJECTIVE

To investigate Thiomucase allergens and their possible relationship with dander allergens and animal albumins.

MATERIAL AND METHODS

Skin prick tests (SPT) and serum-specific IgE were performed with Thiomucase and danders. Thiomucase SDS-PAGE immunoblotting was performed in order to study allergens. RAST/CAP inhibition and SDS-PAGE immunoblotting inhibition were carried out to study the cross-reactivity.

RESULTS

Skin prick tests (SPT) were positive to Thiomucase, animal dander (cat, dog, sheep, other), bovine serum albumin (BSA), and echinococcus. Specific IgE was also positive to Thiomucase, animal dander (cat, dog, sheep, other), BSA and echinococcus. In the RAST-CAP inhibition assays BSA was nearly completely inhibited by Thiomucase, Thiomucase was partially inhibited by BSA and cat and Echinococcus granulosus was partially inhibited by sheep and Thiomucase. In the Thiomucase SDS-PAGE immunoblotting several proteins fixed IgE, ranging from 20 kDa to > 94 kDa, the strongest with 43 kDa. The IgE fixation to BSA, cat and sheep in the SDS-PAGE immunoblotting was completely inhibited by the preincubation of the serum with Thiomucase.

CONCLUSIONS

An IgE-mediated anaphylaxis to Thiomucase is documented. Multiple allergens are recognized in Thiomucase by the patient serum, the main with 43 kDa. Partial cross-reactivity with BSA, cat dander and sheep dander is documented.

Effect of treatment with different doses of 17-beta-estradiol on the insulin receptor

The mechanism for the development of insulin resistance in normal pregnancy is complex and is associated with serum levels of sex hormones. However, the influence of these hormones on the early steps of insulin action has not been extensively studied, although the potentially beneficial effect of estradiol on glucose homeostasis has been reported. In this paper, we attempted to determine the effect of 17-beta-estradiol on the insulin receptor of ovariectomized rats treated with different doses of hormones. Our results showed a tissue-dependent response to estradiol. We found that low doses of estradiol increased the amount of insulin receptors in liver and muscle on days 6 and 11 of treatment but not in adipose tissue, and after 16 days only the muscle responsed in this way. On the other hand, high doses of estradiol significantly decreased the amount of insulin receptors, at least in muscle and adipose tissue. We believe that the low concentrations of 17-beta-estradiol (similar to early pregnancy) could be responsible for the increase in insulin sensitivity by increasing the amount of insulin receptors in peripheral tissues. When the hormone levels were high (similar to late pregnancy) the amount of insulin receptors decreased in peripheral tissues, and insulin sensitivity is diminished just as in late pregnancy. The specific molecular mechanism for this action is as yet unknown.

Protein tyrosine phosphatases

The molecular mechanisms of signal transduction have been at the focus of increasingly intense scientific research. As a result, our understanding of protein tyrosine kinase-mediated signaling has advanced at an unprecedented pace during the past decade. In contrast, the study of protein tyrosine phosphatases has lagged behind, but is now gathering momentum and is predicted to become a "hot topic" in the field within the next few years. This review summarizes the current state-of-the art in our understanding of the structure, regulation and role of protein tyrosine phosphatases with emphasis on the lymphocyte system.

Waldenström macroglobulinaemia: presenting features and outcome in a series with 217 cases

In this report we analyse the presenting features of a series of patients diagnosed with Waldenström macroglobulinaemia (WM) in Spain over the last 10 years. Criteria for diagnosis required a serum monoclonal IgM protein > or = 30 g/l and > 20% bone marrow lymphocytes. Two hundred and seventeen patients were included in the study, with a median age of 69 years and male/female ratio of 2:1. The most common symptoms at diagnosis were anaemia (38%), hyperviscosity (31%), B symptoms (23%), bleeding (23%) and neurological symptoms (22%). Sixty-one patients (27%) were asymptomatic at diagnosis and, to date, 32 of them have not received chemotherapy. Variables predicting a shorter survival free of therapy were haemoglobin < 12.5 g/dl and high beta2microglobulin (beta2M). The 83% of patients who did receive treatment were distributed as follows: chlorambucil/prednisone (43%), intermittent chlorambucil (11%), continuous chlorambucil (26%), cyclophosphamide/vincristine/prednisone (COP, 13.5%) and other (6.5%). Response to therapy was complete in 2%, partial in 48% and minor in 10%. Finally, 28% and 13% of patients presented stable and progressive disease, respectively, which was more common among patients treated with COP. Progression-free survival was 43% at 5 years, with three independent predictors for shorter progression-free survival (PFS): COP treatment, age > 65 and B symptoms at diagnosis. The 10-year projected overall survival (OS) was 55%. The two most frequent causes of death were development of second malignancies (31%), or infections (19%). The two main variables predicting a poor OS were hyperviscosity and high beta2M. In summary, this study favours the use of chlorambucil-based therapy as the standard treatment for WM, and describes a subset of patients who should be considered as suffering a smouldering form and who therefore do not require treatment for a long period of time.

Stratum corneum protein dynamics as evaluated by a spin-label maleimide derivative: effect of urea

The stratum corneum (SC) protein dynamics in the sulfhydryl group regions was studied by electron paramagnetic resonance (EPR) spectroscopy of a covalently attached maleimide derivative spin label. A two-state model for the nitroxide described the coexistence of two spectral components in the EPR spectra. The so-called strongly immobilized component arises from a spin-label fraction with the nitroxide moiety hydrogen-bonded to protein (rigid structure) and the weakly immobilized component is provided by the spin labels with higher mobility (approximately 10 times greater) exposed to the aqueous environment. The relative populations between these two states are in thermodynamic equilibrium. The apparent energetic gain for the nitroxide to form a hydrogen bond with the backbone rather than to be dissolved in the local environment was approximately 10 kcal/mol in the temperature range of 2-30 degrees C and approximately 6 kcal/mol in the range of 30-70 degrees C. Urea treatment caused a drastic increase in the segmental motion of the polypeptide chains that was completely reversible by its removal. Our analyses also indicated that the urea induced unfolding of the SC proteins opening the thiol group cavities. This work can also be useful to improve the spectral analysis of site-directed spin-labeling, especially for a more quantitative description of the nitroxide side chain mobility.

Brucella lipopolysaccharides induce cyclooxygenase-2 expression in monocytic cells

Human brucellosis is characterized by the presence of both acute inflammatory episodes and chronic inflammation with granuloma formation. On this basis, the proinflammatory effects of smooth lipopolysaccharide of Brucella (S-LPS) were addressed and compared to those of LPS from Escherichia coli. For this purpose, the induction of cyclooxygenase-2 (COX-2), the production of the chemokine monocyte chemoattractant protein-1 (MCP-1), and the activation of the nuclear factor kappa B (NF-kappa B) were studied. S-LPS was found to induce both COX-2 expression and MCP-1 production; however, the potency of E. coli LPS exceeded that of Brucella S-LPS by some orders of magnitude. However, at concentrations above 1 microg/ml, all of the LPS produced comparable effects, including their ability to activate the NF-kappa B system. These observations help explain the inflammatory events associated with Brucella infection and the ability of Brucella to produce monocyte recruitment and granuloma formation.

Topographic changes of focal adhesion components and modulation of p125FAK activation in stretched human periodontal ligament fibroblasts

Mechanical stress has been shown in vitro to modulate integrin-beta1-mediated activation of p125FAK/FAK. To test the hypothesis whether this also applies to periodontal ligament fibroblasts (PDLs), we subjected human PDLs to mechanical stretch and analyzed stress-induced changes of p125FAK activation by quantitative immunoprecipitation of p125FAK and changes in the topography of molecules localizing in focal adhesions by indirect immunofluorescence. Generally, all components of focal contacts under study-including detection of phosphotyrosine, i.e., integrin-beta1, p125FAK, and paxillin-revealed a relative co-localization during stretch application. Under stretch, we observed a re-distribution of all components from the cell periphery to the cytoplasm following the main axes. Tyrosine phosphorylation of p125FAK was monitored up to 72 hours under stretch. While the amount of p125FAK remained essentially constant, the activation of p125FAK was clearly modulated. Tyrosine phosphorylation of p125FAK increased from 15 minutes up to 1 hour and declined after stretching periods of 24, 48, and 72 hours. The analysis of our data indicated a stretch-induced redistribution of focal adhesion components and a modulation of p125FAK activation, suggesting alterations in focal adhesions and their associated signal cascade.

Fatal pulmonary thromboembolism after laparoscopic cholecystectomy

A 67-year-old woman presented with severe cardiopulmonary insufficiency 17 days after an uneventful laparoscopic cholecystectomy. Pulmonary thromboembolism was demonstrated by transthoracic echocardiogram and later confirmed at surgery. With the aid of a cardiopulmonary bypass, a thrombectomy of the right atrium and the pulmonary artery was accomplished. The patient could not be weaned off cardiopulmonary bypass and ultimately died. We therefore recommend antithromboembolism therapy with low-molecular-weight heparin in selected cases of laparoscopic cholecystectomy.

Comparative pharmacokinetics and pharmacodynamics of amlodipine in hypertensive patients with and without type II diabetes mellitus

Recent clinical trials aimed at attenuating complications in diabetes mellitus have generated interest in the impact of drug formulation and altered pharmacokinetics and pharmacodynamics in diabetes. Specifically, it has been proposed that the diabetic state may alter the pharmacokinetics of several cardiovascular drugs, including some calcium antagonists. The present study investigates the effects of diabetes mellitus on the pharmacokinetics and pharmacodynamics of amlodipine in hypertensive subjects with and without diabetes mellitus to determine whether the diabetic state alters these parameters. This trial consisted of a 2-week placebo washout phase, a 2-week titration phase, and a 2-week maintenance phase. Study patients included 18 hypertensive patients with type II diabetes mellitus and 10 nondiabetic hypertensive patients. Blood samples were collected after administration of amlodipine and AUC, Cmax, and tmax were determined. The acute 24-hour pharmacodynamic response to amlodipine was assessed by blood pressure and telemetric heart rate measurements. There were no significant differences for either amlodipine 5 or 10 mg in AUC (p = 0.40 for 5 mg; p = 0.59 for 10 mg), Cmax (p = 0.41 for 5 mg; p = 0.45 for 10 mg), and tmax (p = 0.79 for 5 mg; p = 0.67 for 10 mg) between diabetic and nondiabetic hypertensive subjects. Similarly, the 24-hour pharmacodynamic effects of amlodipine on systolic blood pressure, diastolic blood pressure, and heart rate did not differ between diabetic and nondiabetic subjects as assessed by repeated-measures analysis of variance. Because of the theoretical basis for anticipating that diabetes mellitus may provoke important pharmacokinetic and pharmacodynamic alterations, our study provides an important database in clearly demonstrating that the diabetic milieu did not alter the pharmacokinetics or pharmacodynamics of amlodipine.

Structural study of a possible neoplasia detected in Mytilus galloprovincialis collected from the Ria of Vigo (NW Spain)

Several specimens of Mytilus galloprovincialis, collected in the Ria of Vigo over a non-consecutive 2 yr period (1993 to 1994 and 1996 to 1997), presented a possible gonadal neoplasm, entailing morphologically abnormal germinal cells distributed throughout the follicle and invading the adjacent storage tissue. In some cases, affected cells were noted in gonoducts and in haemic sinusoids. Prevalence of this anomaly in the samples was 6%, and all affected individuals were found between April and June. During the rest of the year, individuals presented normal gonadal tissue.

Expression of multidrug efflux pump SmeDEF by clinical isolates of Stenotrophomonas maltophilia

The presence of the multidrug efflux pump SmeDEF was assessed in a collection of clinical isolates of Stenotrophomonas maltophilia. All isolates encoded this pump, as demonstrated by PCR. Forty-seven percent of the strains overproduced a protein of the same size that was immunoreactive against an anti-SmeF antibody, and 33% overexpressed the gene semD when they were tested by reverse transcription-PCR. A correlation between smeDEF overexpression and antibiotic resistance was observed.

Purification and characterization of insulin-mimetic inositol phosphoglycan-like molecules from grass pea (Lathyrus sativus) seeds

BACKGROUND

Signal transduction through the hydrolysis of glycosyl-phosphatidylinositol (GPI) leading to the release of the water-soluble inositol phosphoglycan (IPG) molecules has been demonstrated to be important for mediating some of the actions of insulin and insulin-like growth factor-I (IGF-I).

MATERIALS AND METHODS

In the present study, GPI from grass pea (Lathyrus sativus) seeds has been purified and partially characterized on the basis of its chromatographic properties and its compositional analysis.

RESULTS

The results indicate that it shows similarities to GPI previously isolated from other sources such as rat liver. IPG was generated from L. sativus seed GPI by hydrolysis with a GPI-specific phospholipase D (GPI-PLD). This IPG inhibited protein kinase A (PKA) in an in vitro assay, caused cell proliferation in explanted cochleovestibular ganglia (CVG), and decreased 8-Br-cAMP-induced phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression in cultured hepatoma cells.

CONCLUSIONS

Our data indicate that L. sativus seed IPG possess insulin-mimetic activities. This may explain why L. sativus seeds have been used in some traditional medicines to ameliorate diabetic symptoms.

Effect of treatment with different doses of 17-beta-estradiol on insulin receptor substrate-1

CONTEXT

Ovarian hormones modulate insulin sensitivity, but their exact role remains unclear.

OBJECTIVE

We tried to determine whether different doses of 17-beta-estradiol cause changes in the regulation of insulin receptor substrate (IRS-1) levels, and if so, the possible implications in insulin sensitivity.

DESIGN

Ovariectomized rats were treated with different doses of 17-beta-estradiol at 6, 11 and 16 days.

MAIN OUTCOME MEASURES

Immunoprecipitation and Western blotting for IRS-1 were performed in different tissues.

RESULTS

We found that estradiol treatment has an influence on the amount of IRS-1 but that it acts in different ways depending on the tissue studied, on the length of treatment, and on the doses employed.

CONCLUSIONS

Our results suggest that low concentrations of 17-beta-estradiol could be responsible for the upregulation of insulin receptor substrate 1, increasing insulin sensitivity in muscle and adipose tissue. However, insulin receptor substrate 1 is downregulated with high concentrations of 17-beta-estradiol, thus these high hormone plasma levels could favour insulin resistance in peripheral tissues. The role of 17-beta-estradiol seems to modulate insulin receptor substrate 1 levels in insulin dependent tissues, but in a different manner in each tissue. These novel findings are important for improving knowledge about the possible risk for insulin resistance in women taking oral contraceptives or receiving hormone replacement therapy at menopause.