Linac stereotactic radiosurgery for the treatment of small arteriovenous malformations: lower doses can be equally effective

OBJECTIVE

The purpose of this study was to examine the efficacy and toxicity of treating small arteriovenous malformations (AVMs) (≤3 cm in diameter) with a median marginal applied dose of 14 Gy.

METHODS

Two hundred and thirteen patients diagnosed with AVMs were treated between January 1991 and December 2005. Seventy-three percent of the patients had hemorrhaged prior to treatment, 13% had had previous surgery and 19.2% had had previous embolization. The median follow-up duration was 48.1 months.

RESULTS

The Kaplan-Meier analysis estimated that the 36-month obliteration rate was 65.5% for patients undergoing their first stereotactic radiosurgery (SRS) and 68.3% for those undergoing repeated SRS. The Kaplan-Meier analysis estimated the 60-month AVMs obliteration rate for the entire cohort to be 82.4%. The median time to AVM obliteration was 40 ± 2.8 months. We found a statistically significant relationship between the time of obliteration and the following factors: site of the AVMs (sites other than brainstem), a higher prescribed dose and a positive history of previous hemorrhage. Thirteen patients (7.6%) experienced toxicities.

CONCLUSIONS

SRS was an effective and safe treatment for AVMs ≤3 cm in diameter, with acceptable toxicity.

Regulation of lipoprotein lipase gene expression by insulin and troglitazone in rainbow trout (Oncorhynchus mykiss) adipocyte cells in culture

Adipose tissue plays a central role regulating the balance between deposition and mobilization of lipid reserves. Lipoprotein lipase (LPL) is a key enzyme controlling lipid accumulation in mammals and fish. In the present study, we have examined the expression of LPL in rainbow trout cultured adipocytes and we have investigated the effect of troglitazone, a member of thiazolidinediones (TZDs), and insulin on its expression. LPL gene expression increased from day 1 until day 12 of culture, and the level was maintained up to day 21. The addition of insulin at 10 nM and 1.7 μM increased significantly LPL gene expression in undifferentiated cells (days 7 to 12 maintained in growth medium). Nevertheless, treatment of day 7 cells incubated in growth medium with troglitazone (5 μM) or troglitazone plus insulin (1 μM each), tended to enhance LPL expression. In addition, LPL mRNA levels increased significantly in the presence of 1 μM and 5 μM of troglitazone (days 7 to 12) when the cells were induced to differentiate by addition of differentiation medium. Although troglitazone alone (1 μM) did not stimulate lipid accumulation in the cells neither in growth nor in differentiation medium, the simultaneous presence of troglitazone (1 μM) and insulin (1 μM) increased significantly the content of triglycerides in adipocyte cells maintained in growth medium (days 7 to 12). These results indicate that insulin and troglitazone regulate LPL gene expression during adipocyte differentiation and suggest that both factors may have combined effects in the modulation of adipogenesis.

Glucose depletion in the airway surface liquid is essential for sterility of the airways

Diabetes mellitus predisposes the host to bacterial infections. Moreover, hyperglycemia has been shown to be an independent risk factor for respiratory infections. The luminal surface of airway epithelia is covered by a thin layer of airway surface liquid (ASL) and is normally sterile despite constant exposure to bacteria. The balance between bacterial growth and killing in the airway determines the outcome of exposure to inhaled or aspirated bacteria: infection or sterility. We hypothesized that restriction of carbon sources--including glucose--in the ASL is required for sterility of the lungs. We found that airway epithelia deplete glucose from the ASL via a novel mechanism involving polarized expression of GLUT-1 and GLUT-10, intracellular glucose phosphorylation, and low relative paracellular glucose permeability in well-differentiated cultures of human airway epithelia and in segments of airway epithelia excised from human tracheas. Moreover, we found that increased glucose concentration in the ASL augments growth of P. aeruginosa in vitro and in the lungs of hyperglycemic ob/ob and db/db mice in vivo. In contrast, hyperglycemia had no effect on intrapulmonary bacterial growth of a P. aeruginosa mutant that is unable to utilize glucose as a carbon source. Our data suggest that depletion of glucose in the airway epithelial surface is a novel mechanism for innate immunity. This mechanism is important for sterility of the airways and has implications in hyperglycemia and conditions that result in disruption of the epithelial barrier in the lung.

Role of insulin and IGF-I on the regulation of glucose metabolism in European sea bass (Dicentrarchus labrax) fed with different dietary carbohydrate levels

The roles of insulin and insulin-like growth factor-I (IGF-I) in the regulation of glucose metabolism were assessed in European sea bass juveniles fed with distinct dietary carbohydrate levels. Three isonitrogenous diets were formulated to contain 10% (10%PGS) or 30% (30%PGS) pregelatinized starch or no starch (control). The highest plasma glucose and insulin levels were observed 6h after feeding in fish receiving the 30%PGS diet. Although plasma IGF-I was higher at 6h than at 24h after feeding, no effect of dietary carbohydrate level was noticed within each sampling time. Increasing dietary carbohydrate level resulted in an increase of liver but not of muscle glycogen content. Hepatic glucokinase (GK) and glucose-6-phosphate dehydrogenase (G6PD) activities increased with the dietary carbohydrate content, whereas pyruvate kinase (PK) activity was higher in fish fed the carbohydrate containing diets than the carbohydrate-free diet. GK activity was higher 6h than 24h after feeding, whereas the opposite was observed for G6PD activity. Data suggest that under the nutritional conditions assayed plasma glucose is an insulin secretagogue. Furthermore, insulin appears to have a more important role than IGF-I in stimulating hepatic glucose uptake, thus enhancing GK activity and leading to an increase in liver glycogen content to maintain glucose homeostasis.

Insulin and insulin-like growth factor I signaling pathways in rainbow trout (Oncorhynchus mykiss) during adipogenesis and their implication in glucose uptake

Primary cultures of rainbow trout ( Oncorhynchus mykiss ) adipocytes were used to examine the main signaling pathways of insulin and insulin-like growth factor I (IGF-I) during adipogenesis. We first determined the presence of IGF-I receptors (IGF-IR) and insulin receptors (IR) in trout preadipocytes ( day 5) and adipocytes ( day 14). IGF-IRs were more abundant and appeared to be in higher levels in differentiated cells than in preadipocytes, whereas IRs were detected in lower but constant levels throughout the culture. The cells were immunoreactive against ERK1/2 MAPK, and AKT/PI3K, components of the two main signal transduction pathways for insulin and IGF-I receptors. Stimulation of MAPK phosphorylation by IGF-I was higher in preadipocytes than in adipocytes, while no effects were observed in MAPK phosphorylation after incubation of cells with insulin. AKT phosphorylation increased in the presence of both insulin and IGF-I, with higher levels of stimulation in adipocytes than in preadipocytes. Activation of both pathways was blocked by the use of specific inhibitors of MAPK (PD98059) and AKT (wortmannin). We describe here, for the first time, the effects of IGF-I and insulin on 2-deoxyglucose uptake in primary culture of trout adipocytes. IGF-I was more potent in stimulating glucose uptake than insulin, and PD98059 and wortmannin inhibited the stimulation of glucose uptake by this growth factor, suggesting that IGF-I plays an important metabolic role in trout adipocytes. Our results suggest that differential activation of the MAPK and AKT pathways are involved in the IGF-I- and insulin-induced effects of trout adipocytes during the various stages of adipogenesis.

[Vasoconstriction is required for edema of contralateral lung after reperfusion injury of one lung]

Ischemia-reperfusion (IR) lung injury is a significant cause of morbidity and mortality in certain clinical scenarios that include transplantation, thromboendarterectomy and reexpansion injury of the lung. Edema of the contralateral lung after IR injury of one lung has been reported and this study was aimed to clarify the pathophysiology of this phenomenon. One-lung ischemia/hypoxia followed by reperfusion with either blood or an acellular plasma substitute was achieved in an isolated rabbit lung model by hilum clamping. After reperfusion, we studied the isolated effects of vasoconstriction and inflammation on contralateral lung injury by using papaverine or hydrocortisone as vasodilator and anti-inflammatory, respectively. We observed that IR of one lung induces edema of the contralateral lung. Absence of leukocytes and platelets in the perfusate or use of hydrocortisone completely inhibits IR injury. Moreover, papaverine suppresses edema of the contralateral, but not that of the reperfused lung. We concluded that IR of one lung produces edema in the contralateral lung that requires vasoconstriction of the latter.

Induction of tolerance in renal transplantation using splenic transplantation: experimental study in a canine model

OBJECTIVE

To evaluate in a canine model the induction of tolerance to renal transplantation after splenectomy and splenosis.

MATERIALS AND METHODS

This prospective, experimental, comparative, longitudinal study included 4 experimental groups, each comprising 4 dogs. Group 1 (control group) underwent renal transplantation only; group 2 underwent renal transplantation and splenectomy; group 3 underwent renal transplantation and splenosis; and group 4 underwent renal transplantation, splenectomy, and splenosis. Survival and degree of rejection were compared between the 4 groups.

RESULTS

Splenosis improved renal function after transplantation, as indicated by increased serum creatinine concentration (group 3, 6.2 mg/dL vs group 1, 12.9 mg/dL). Comparison of weighted survival curves (corrected for degree of rejection) demonstrated a significant difference between group 2 (66.0 days) and group 4 (66.2 days) vs group 1 (52.7 days) and group 3 (41.2 days) (P = .05, Wilcoxon rank sum test).

CONCLUSION

These results suggest that in this experimental model of renal transplantation, splenosis and splenectomy induce clinical tolerance, as indicated by improved renal function and prolonged recipient survival.

Increasing early diagnosis of HIV through rapid testing in a street outreach program in Spain

Our goal was to analyze the results of a multicity program offering rapid HIV testing in a mobile unit in central locations. Between October 2006 and December 2007, 7138 persons were tested, providing a finger-prick blood sample and filling out a brief questionnaire while waiting for the results of the Determine((R)) test. Seventy people were classified as reactive and 3 as indeterminate. Confirmatory test results were obtained for 83.6%. Of the 56 reactive persons contacted, 2 were confirmed as negative, giving a positive predictive value of 96.6%. Those tested were primarily men (60.6%), persons with university education (47.4%), and included a large percentage of immigrants (26.2%), especially from Latin America, and 37.3% were men who have sex with men (MSM). Forty-seven percent had ever been tested for HIV. Global HIV prevalence was 0.98% (confidence interval [CI]: 0.75-1.21), 1.59%, (CI: 1.21-1.97) in men and 0.19%, (CI: 0.02-0.35) in women. In the tree analysis the high prevalence node included Latin Americans with only primary studies (study level finished at least at the age of 12). Of the 64% HIV-positive tests in 2007 with available CD4 counts, 18.75% had CD4 counts under 350. Street-based mobile units offering rapid HIV testing in selected sites, may diagnose HIV at an earlier stage of infection than clinic-based sites, and have a low rate of false-positives.

Molecular analysis of the replication region of the pCIZ2 plasmid from the multiple bacteriocin producer strain Enterococcus faecium L50

The sequence analysis of the 7383 bp plasmid pCIZ2 from Enterococcus faecium L50 enabled the identification of a DNA region involved in its replication. The structural organization of the pCIZ2 replication region is highly similar to those of well-known theta-replicating plasmids. It contains an untranslated region, the putative replication origin (ori), constituted by two sets of direct repeats of 12 and 22 bp (iterons), and followed by three open-reading frames (orf8 to orf10). orf8 encodes the replication initiation protein (RepE). The transcriptional start site of the replication locus was identified 13 nucleotides upstream of the repE start codon. A two-dimensional agarose gel electrophoresis analysis revealed pCIZ2 intermediates profile typical of the theta-type replication mechanism. Subcloning of different DNA fragments of the pCIZ2 replication region in Escherichia coli and, subsequently, in the plasmidless E. faecium L50/14-2 allowed the determination of the minimal replicon on a 1.2kb DNA fragment containing only the overall ori and repE which also act in trans. The involvement of orf9 in the plasmid copy number and in the plasmid stability was investigated. The pCIZ2 recombinant plasmids constitute narrow-host range shuttle cloning vectors (E. coli-E. faecium) that could be very useful for enterococcal genes studies, allowing an easy identification due to their histochemical recognition.

Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss)

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

[Effect of hypocapnia/alkalosis on the fluid filtration rate in isolated and perfused rabbit lungs]

Hypocapnia/alkalosis is a consequence of several lung and metabolic pathologies. The aim of this study was to determine whether the increase of fluid filtration rate (FFR) that occurs during Hypocapnia/alkalosis circumstances is determined by hypocapnia, alkalosis or both. 7 groups were formed (N=36) using isolated rabbit lungs. Group 1: Control (PCO2 6%, pH: 7.35-7.45); Group 2 (n=6): Hypocapnia/Alkalosis (CO2 1%, pH: 7.9); Group 3 (n=6): Hypocapnia/Normo-pH (CO2 1% pH 7.35-7.45), Group 4 (n=6) Normocapnia/Alcalosis (CO2 6%, pH: 7.9). Fenoterol, papaverine and hydrocortisone were added to Groups 5, 6 and 7 (n=4) respectively, all under Normocapnia/Alkalosis. FFR and Pulmonary Arterial Pressure (Pap) were considerably higher in group 2 than in control (FFR: 1.92g/min +/- 0.6 vs 0.0 g/min +/- 0.006). A strong influence exerted by pH was observed when Group 3 and group 4 were compared (FFR: 0.02 g/min +/- 0.009 vs 2.3 g/min +/- 0.9) and (Pap: 13.5 cmH2O +/- 1.4 vs 90 cmH2O +/- 15). A reduced effect was observed in groups 5 and 6 (papaverine and hydrocorisone) and a totally abolished effect was observed in group 7 (fenoterol) (FFR: 0.001 +/- 0.0003 mL/min and Pap: 14 +/- 0.8 cmH2O). Pulmonary edema induced by Hypocapnia/alkalosis is a consequence of alkalosis and not of hypocapnia. This effect could be due to inflammatory damage in the lung parenchyma and alkalosis-mediated vasoconstriction.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

The relation among the diameter of the great saphenous vein, clinical state and haemodynamic pattern of the saphenofemoral junction in chronic superficial venous insufficiency

OBJECTIVE

To find out if there is a relation among the diameter of the great saphenous vein (GSV) when it is incompetent, the clinical gravity of the varicose syndrome and the type of insufficiency of the saphenofemoral junction (SFJ) in patients with chronic venous insufficiency (CVI) by means of duplex exploration.

METHODS

The sample included 145 extremities, 38 normal as a control group and 107 with incompetence of the GSV. According to the results of the Valsalva and Parana manoeuvres in the SFJ, they were distributed into four groups. The diameter of the GSV and the clinical state according to the clinical, aetiological, anatomical and pathological element classification were recorded for each group.

RESULTS

Statistically significant differences were obtained for the diameter and the clinical state in patients with positive manoeuvres with regard to other groups. The diameter was greater and the clinical state more severe (C4, C5 and C6) when two manoeuvres were positive.

CONCLUSIONS

The presence of both positive manoeuvres in the SFJ is related to severe clinical states and greater diameters of the GSV, allowing the establishment of a prognosis of the CVI and the most suitable surgical approach.

[Analysis of lung cancer cases diagnosed in an internal medicine department: from January 2001 to September 2006]

BACKGROUND

Lung cancer is one of the main health problems in the developed world. Our aims were to determine the symptomatic time prior to a specific diagnosis, the clinical and histological characteristics of the cases of lung cancer diagnosed in a department of internal medicine, and to analyze the survival factors.

MATERIAL AND METHODS

We studied retrospectively all patients diagnosed with lung cancer in the internal medicine department in the period between January 2001 and September 2006 reviewing clinical records. We specifically recorded age, gender, smoking habit, time and type of symptomatic presentation, radiological manifestations, methods of histological diagnosis, tumour staging, and performance status measured by ECOG classification. We also evaluated the factors associated with the survival time.

RESULTS

In this period 124 patients were diagnosed with lung cancer [mean age 68 +/-12 years, male 105 (85%), female 18 (15%), smokers 85%]. The mean symptomatic time before hospitalization was 74.5 +/-7 days. On hospitalization, respiratory symptoms were present in 40 (32%) patients. Tumour staging was carried out in 120 (97%) patients. In 96 (77%) patients non-small lung cancer was diagnosed, 62 (64%) in stage IV. In 28 (23%) patients small lung cancer was diagnosed, 22 (79%) in extended stage. Median time to diagnosis as an in-patient was 7 days. One hundred and thirteen (91%) patients died with a median survival time of 3 months. Factors associated with longer survival were the performance status and tumour stage.

CONCLUSIONS

In this community, lung cancer is diagnosed late and in advanced stages, with a high mortality rate. A better performance status and lower tumour stages appear to be associated with longer survival.

Diabetes team consultation: impact on length of stay of diabetic patients admitted to a short-stay unit

OBJECTIVE

To assess the impact of endocrinology team consultation on hospital stay and clinical outcomes of diabetic patients admitted with a primary non-diabetes-related diagnosis in a short stay unit (SSU).

METHODS

Patients admitted to the SSU between 2001 and 2005. Between 2001 and 2003 there was no endocrinology team consultation available and the management of hyperglycemia was handled by the SSU team alone. From 2003 until 2005 an endocrinology team was in charge of diabetes care. We compared in both periods: prevalence of diabetes, length of hospital stay, mortality, early readmissions and number of patients requiring conventional hospitalization.

RESULTS

In period 2001-2003, 1023 patients were admitted, among which 212 were diabetic (20.7%). Over the years 2003-2005, 892 patients were hospitalized, 223 were diabetic (25%). Clinical characteristics of diabetic patients from both periods were comparable, but glycaemia at admission was higher on the second period (217 mg/dl versus 198 mg/dl). The length of stay of diabetic patients in the second period decreased from 5.49 to 4.90 days. There were no significant differences in mortality (1.4% versus 0.4%) or in early re-admissions among the two periods.

CONCLUSIONS

The intervention of a diabetes team diminished the average length of stay of diabetic patients.

Insulin regulation of lipoprotein lipase (LPL) activity and expression in gilthead sea bream (Sparus aurata)

Lipoprotein lipase (LPL) is a key enzyme in lipoprotein metabolism by virtue of its capacity to hydrolyze triglycerides circulating in the form of lipoprotein particles. Here we analyzed the fasting effects of LPL in gilthead sea bream (Sparus aurata) and also present the first study in fish of the role of insulin as a potential modulator of both LPL activity and expression. Fasting for 2 weeks provoked a clear decrease in adipose tissue LPL activity, concomitant with lower levels of plasma insulin, while no effects were observed in red muscle. To elucidate the specific role of insulin, increases of plasma insulin were experimentally induced by arginine and insulin injections. However, arginine predominantly stimulated glucagon over insulin secretion in this fish species while LPL activity did not change significantly in adipose tissue. Instead, insulin administration induced an increase in adipose tissue LPL activity 3 h after the injection, whereas LPL activity in red muscle was not affected. Changes in LPL activity were accompanied by an increase in LPL mRNA levels in the adipose tissue of insulin-injected gilthead sea bream, although changes in LPL expression were delayed in time with respect to variations in LPL activity. Finally, LPL mRNA levels in red muscle were similar between control and insulin-injected gilthead sea bream, suggesting that insulin does not play a direct role in the regulation of LPL in this tissue. The current study shows that LPL activity is regulated by nutritional condition and underscores the importance of insulin as a modulator of LPL activity and expression in the adipose tissue of gilthead sea bream.