A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude.

Early to Middle Miocene sea-level oscillations of approximately 40-60 m estimated from far-field records1-3 are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene4,5. Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during the Early Miocene (~17.72-17.40 Ma). Geochemical and petrographic data show glacimarine sediments recovered at International Ocean Discovery Program (IODP) Site U1521 in the central Ross Sea derive from West Antarctica, requiring the presence of a WAIS covering most of the Ross Sea continental shelf. Seismic, lithological and palynological data reveal the intermittent proximity of grounded ice to Site U1521. The erosion rate calculated from this sediment package greatly exceeds the long-term mean, implying rapid erosion of West Antarctica. This interval therefore captures a key step in the genesis of a marine-based WAIS and a tipping point in Antarctic ice-sheet evolution.

Factors Influencing Serum Concentrations of Immunoglobulin D in the Adult Population: An Observational Study in Spain.

Immunoglobulin D (IgD) is the least studied of immunoglobulin classes. This study sought to investigate the potential relationship between demographic, metabolic, lifestyle and immunological factors, and serum IgD concentrations in a general adult population. We measured serum IgD concentrations by means of a commercial turbidimetric assay in 413 individuals (median age, 55 years; 45% males), randomly selected from the adult population of a Spanish municipality. Serum IgD concentrations displayed considerable variation in the population, ranging from undetectable (<6.7 mg/l) to 878 mg/l. Serum IgD concentrations were undetectable in 78 cases (18.9%) and >100 mg/l in 39 cases (9.4%). Median IgD was 21.9 mg/l. Serum IgD concentrations were negatively associated with age and positively associated with smoking, after adjustment for potential confounders. Overweight individuals showed lower concentrations of IgD than did normal-weight individuals. Atopy (positivity of skin tests to aeroallergens) was not significantly associated with IgD concentrations, although non-symptomatic atopics showed higher IgD concentrations. No consistent association was observed between serum IgD concentrations and gender, metabolic syndrome, or alcohol consumption. No significant association was found between baseline IgD concentrations and development of either allergic or immune disease after a median 11.4 years of follow-up. In conclusion, serum IgD concentrations in adults show a wide variation in the population and may be influenced by common factors, particularly age and smoking habit. These factors should be taken into account when defining reference ranges for serum IgD concentrations.

Simultaneous tyrosine and serine phosphorylation of STAT3 transcription factor is involved in Rho A GTPase oncogenic transformation.

Stats (signal transducers and activators of transcription) are latent cytoplasmic transcription factors that on a specific stimulus migrate to the nucleus and exert their transcriptional activity. Here we report a novel signaling pathway whereby RhoA can efficiently modulate Stat3 transcriptional activity by inducing its simultaneous tyrosine and serine phosphorylation. Tyrosine phosphorylation is exerted via a member of the Src family of kinases (SrcFK) and JAK2, whereas the JNK pathway mediates serine phosphorylation. Furthermore, cooperation of both tyrosine as well as serine phosphorylation is necessary for full activation of Stat3. Induction of Stat3 activity depends on the effector domain of RhoA and correlates with induction of both Src Kinase-related and JNK activities. Activation of Stat3 has biological implications. Coexpression of an oncogenic version of RhoA along with the wild-type, nontransforming Stat3 gene, significantly enhances its oncogenic activity on human HEK cells, suggesting that Stat3 is an essential component of RhoA-mediated transformation. In keeping with this, dominant negative Stat3 mutants or inhibition of its tyrosine or serine phosphorylation completely abrogate RhoA oncogenic potential. Taken together, these results indicate that Stat3 is an important player in RhoA-mediated oncogenic transformation, which requires simultaneous phosphorylation at both tyrosine and serine residues by specific signaling events triggered by RhoA effectors.

Serum cytokeratins in alcoholic liver disease: contrasting levels of cytokeratin-18 and cytokeratin-19.

Serum cytokeratin (CK) levels are widely used as tumor markers. Serum levels of CK-18, a tumor marker also known as tissue polypeptide specific antigen (TPS), are increased in patients with alcoholic liver disease. Cytokeratin-18 is the main component of Mallory bodies, a hallmark of alcoholic hepatitis, which may also contain CK-19. Serum levels of CK-18 and CK-19, a tumor marker also known as CYtokeratin FRAgment 21-1 (CYFRA 21-1) were investigated in (a) heavy drinkers with alcoholic liver disease (n=15), (b) patients with malignancy (n=22), and (c) healthy controls (n=10). Serum levels of CYFRA 21-1 (CK-19) were markedly increased in patients with malignancy, but were similar in heavy drinkers and healthy controls. In contrast, serum levels of TPS (CK-18) in heavy drinkers were higher than those of healthy controls, and even tended to be higher than those of patients with malignancy. Both CK-19 and CK-18 levels were higher in cases of alcoholic hepatitis than in cases of fatty liver. Correlation with hepatocyte CK inclusions was stronger for serum TPS (CK-18) than for CYFRA 21-1 (CK-19). In conclusion, serum CYFRA 21-1 (CK-19) and TPS (CK-18) show a different pattern of increase that could reflect the composition of the altered hepatocyte CK network in alcoholic liver disease. Their usefulness as tumor markers, particularly that of serum TPS (CK-18), may be limited in patients with alcoholic liver disease.

Assay of beta-N-acetylhexosaminidase isoenzymes in urine by means of determination of their activation energy without removing endogenous low-molecular-mass components.

The determination of the activation energy of beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52), using 3,3'-dichlorophenylsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide as substrate, allows its isoenzyme composition to be evaluated in different biological specimens. However, in the analysis of urine samples, it is necessary first to remove the endogenous low-molecular-mass components, as these provoke an over-estimation of the activation energy of the Hex and, consequently, of the relative proportion of Hex B isoenzyme. The study of this interference has allowed urea to be characterised as the only urinary metabolite that is responsible, and to establish a mathematical expression for the correction, in relation to the endogenous urea concentration, of the activation energy of the Hex obtained experimentally in samples of native urine. The results thus obtained for the isoenzyme composition of urinary Hex are similar to those found using an electrophoretic separation procedure.

Thermodynamic characterisation of the mutated isoenzyme A of beta-N-acetylhexosaminidase in GM2-gangliosidosis B1 variant.

Here we report the determination of the activation energies of the plasma isoenzymes of beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52), isolated by chromatography in DEAE-cellulose, using the neutral chromogenic substrate 3,3'dichlorophenylsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide. The activation energy of mutated Hex A isoenzyme (Ea approximately 71.5 kJ/mol) from a patient with GM2-gangliosidosis B1 variant, homozygote for the G533-->A (Arg178His) mutation, was significantly higher than that of normal Hex A (Ea approximately 41.8 kJ/mol) and analogous to that of Hex B isoenzyme (Ea approximately 75.1 kJ/mol). The determination of this thermodynamic variable of Hex in different biological specimens could allow for a straightforward biochemical characterisation of the GM2-gangliosidosis B1 variant.

Pharmacological modification of the serotonergic transmitter system and beta-N-acetylhexosaminidase activity in rats.

The enzyme activity and activation energy of plasma beta-N-acetylhexosaminidase (Hex) was determined in rats whose serotonergic system had been pharmacologically altered. In the group of animals treated with 5-hydroxytryptophan, in the different dissected brain regions (brain stem, cortex and hippocampus) significantly higher levels of serotonin and 5-hydroxyindolacetic acid were found, and significantly lower in the group treated with p-chlorophenylalanine, than in the control group. In the total number of animals studied (n = 21), a statistically significant correlation was found between the plasma concentration of 5-hydroxyindolacetic acid and the levels of this metabolite in the different brain regions (p < 0.001). No significant differences were found for the activity of Hex in the plasma, or for its activation energy, which is a marker of its isoenzyme composition, among the three groups of animals. The results obtained using our experimental model in rats do not confirm the hypothesis of other authors who suggest that the Hex responds secondary to increases or decreases of serotonin turnover, and could be a biological test to monitor the serotonin status in psychiatric patients.

[Surgical treatment of hypospadias. Apropos of 700 hypospadias surgically treated (1966-1988). Indications and results. Current trends of the surgical treatment]. / Consideraciones sobre el tratamiento quirúrgico del hipospadias. A propósito de 700 hipospadias intervenidas (1966-1988). Indicaciones y resultados. Tendencias actuales del tratamiento quirúrgico.

The surgical treatment of hypospadias is very complex. The objective is to obtain a satisfactory urinary and genital function with an equal morphological, anatomical and aesthetic result. Our contribution covers 22 years of surgical multicentre experience (700 cases). We evaluate the surgical indication, results, complications, associated malformations and study protocols. The anterior forms 590 (82%) were treated using the Duckett Magpi, Mathieu, Duplay and Leveuf techniques. Posterior forms 110 (18%) with a wide variety of techniques. Results have been encouraging in both. We have objectively evaluated the evolution of the indications, as well as the application of different techniques depending on the extent of urethral malformation.

[Bivalve transinusal anatrophic nephrolithotomy. Anatomic considerations. New technique]. / Nefrolitotomía anatrófica transinusal bivalva. Consideraciones anatómicas. Nueva tecnica.

The paper describes the experience accumulated over a 9- year period on surgical treatment of coralliform lithiasis. The treatment implied the use of an original technique inspired in the surgical concepts divulged by Gil-Vernet, Kelly and Dufour. Ninety-four patients have been effectively treated with this technique, known as the Bivalve Transinusal Anathropic Nephrothomy. The surgical technique applied is described and analyzed.

Incidence and factors associated with delayed graft function in renal transplantation at Carlos Van Buren Hospital, January 2000 to June 2008.

Delayed graft function (DGF) is defined as the need for dialysis within the first week after renal transplantation, and slow graft function as persistence of serum creatinine concentration of at least 3 mg/dL on day 5 after the procedure. In the present study, we analyzed the incidence and risk factors for DGF at our center. This retrospective study included 106 patients who underwent renal transplantation between January 2000 and June 2008. Of these, 11 patients were excluded. Two of the remaining 95 patients received organs from living donors, and 93 received cadaver organs. Variables analyzed included donor age, cause of death, cause of chronic renal failure, recipient age, method and time of long-term renal replacement therapy, residual diuresis, panel of reactive antibodies (PRA), HLA mismatch, sex compatibility, cold and warm ischemia times, biopsy-confirmed episodes of acute rejection, urine output in the operating room and in the first 24 hours after the procedure, and intraoperative induction therapy. Data were analyzed using the chi(2) and Fisher exact tests and analysis of variance, and are given as mean (SD) and frequency. Variables associated with DGF at univariate analysis (P < .05) were divided between risk factors and predictors of DGF for inclusion in logistic regression models. The incidence of DGF was 32.6%; slow graft function, 16.8%; and immediate graft function, 50.5%. Cold ischemia time longer than 20 hours (P = .02) and donor age (P = .008) were directly associated with DGF. Twenty-four-hour urine output was a strong predictor of DGF. Patients with DGF demonstrated a 25% incidence of an episode of acute rejection before discharge from the hospital. No difference in DGF was observed for use of intraoperative induction therapy.

Antimicrobial properties of moderately halotolerant bacteria from cenotes of the Yucatan peninsula.

AIMS: Isolation and antimicrobial evaluation of aquatic bacterial strains from two cenotes. METHODS AND RESULTS: A total of 258 bacterial strains were isolated from the water and sediment of two cenotes in the Yucatan peninsula, all of which were screened against six pathogenic micro-organisms. Antimicrobial activity was detected in 46 of the isolated strains against at least one of the target strains tested. Antimicrobially active isolates were identified as: Aeromonas, Bacillus, Burkholderia, Photobacterium, Pseudomonas, Serratia, Shewanella, Stenotrophomonas genera, and 13 remained unidentified. All antimicrobially active strains were able to grow in salt medium at a concentration of 75 g l(-1), thus classifying as moderately halotolerant bacteria. Most of the antimicrobially active strains exhibited a broad action spectrum, where 61% was because of uncharacterized antimicrobial substances, 25% because of bacteriocins and 13% because of siderophores. Ten strains were able to biosynthesize biosurfactant metabolites. CONCLUSIONS: Native bacteria from the Yucatan peninsula showed an interesting antimicrobial activity, diverse mode of action and moderate halotolerance to salt. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on bacterial isolates from cenotes of the Yucatan peninsula and their antimicrobial characterization, with great potential for future biotechnological applications.

Assay of serum/plasma beta-N-acetylhexosaminidase isoenzymes by heat inactivation using a continuous spectrophotometric method adapted to a centrifugal analyzer.

Activity of serum/plasma beta-N-acetylhexosaminidase (EC 3.2.1.52) was determined by means of a continuous spectrophotometric method using 3,3'-dichlorophenylsulphonphthaleinyl-N-acetyl-beta-D-glucosaminid e as substrate, with very satisfactory results. Incubation of an undiluted aliquot (1 ml) of samples at 52 degrees C for 8 hours with an adjusted pH 5.5-6.0 provoked only the inactivation of isoenzyme A, thus allowing the evaluation of beta-N-acetylhexosaminidase isoenzyme composition. In 25 serum samples from control subjects and pregnant women, a good correlation between the percentage of isoenzyme B obtained by this procedure and the fluorimetric assay of O'Brien et al. (New Engl J Med 1970; 273:15-20) was found (r = 0.983, S(yx) = 1.51), with no statistically significant difference between the means (43.2 vs 42.8%). In 84 healthy adult subjects, an average value of 30.3% for the proportion of isoenzyme B was obtained, with an interval of 25.4-35.0%, in agreement with results reported by other authors.

Assay of beta-N-acetylhexosaminidase isoenzymes in different biological specimens by means of determination of their activation energies.

The activation energy (Ea) of beta-N-acetylhexosaminidase (Hex, EC 3.2.1.52) was determined with 3,3'-dichlorophenylsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide as substrate, with a much higher value being found for the Hex B isoenzyme (Ea = 75.1 kJ/mol) than for the Hex A isoenzyme (Ea = 41.8 kJ/mol). This fact allowed for the development of a fast and reliable thermodynamic method to determine the isoenzyme composition of Hex in different biological specimens (serum/plasma, saliva, cerebrospinal fluid, seminal plasma, urine, and leukocyte lysates). The results in serum given by the proposed method may be superimposed upon those obtained by the heat inactivation assay of O'Brien et al. (N Engl J Med 1970;273:15-20), and the catalytic activity calculated for Hex A offers a good correlation with that obtained by using the specific substrate 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide-6 sulfate (n = 25, r = 0.953).

Plasma beta-N-acetylhexosaminidase isoenzyme composition and temperature conversion factors.

Using the chromogenic substrate 3,3'-dichlorophenylsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide for the activity determination of plasma beta-N-acetylhexosaminidase (Hex), the temperature conversion factors (TCF) offer a highly significant positive correlation with the relative proportion of Hex B isoenzyme (P< 0.001). The calculation of TCF 37 degrees/25 degrees C allows the isoenzyme composition of Hex to be determined quickly and cheaply. The results may be superimposed over those obtained in a previously described method based on the calculation of the enzyme's activation energy using four temperatures. However, the use of TCF 37 degrees/30 degrees C does not appear to comply with the required demands.

[Meningitis caused by Candida in a premature infant]. / Meningitis por Candida en un prematuro.

A case of Candida meningitis in a premature infant treated with amphotericin B IV for 41 days, resulted in negative CSF cultures after 5 days of therapy. Amphotericin B was also given intraventricularly for 21 days; purulent meningitis was a complication from this kind of therapy. Psychometric evaluation showed a mental age of 3 months in a chronological age of 7 months. Only one premature infant has been reported in the literature with intraventricular amphotericin B treatment. A review of Candida meningitis diagnosed before death in infants less than 1 year of age and a discussion of the modern therapy is presented.

[Interconversion of the results for erythrocyte zinc protoporphyrin expressed in different units]. / Interconversión de los resultados de protoporfirina zinc eritrocitaria expresados en distintas unidades.

As stated in a recent document of the National Committee for Clinical Laboratory Standards (NCCLS Document C42-P, April 1995), expression of the results of erythrocyte zinc protoporphyrin (ZPP) in different units is a main source of confusion which may hamper the wide use of this test. The possible inter-conversion of the ZPP values expressed as microgram/g Hb, microgram/dL blood and microgram/dL red cells was assessed. It was found that in all cases, despite a good correlation between these values (r > or = 0.939), the error of the estimation was higher than allowed by the American College of Pathologists criteria. Such findings show that ZPP values expressed in different units cannot be inter-converted as a function of the corresponding regression equation. Similarly, the use of hematofluorometers with an analogic-digital converter to express results as microgram ZPP/ dL blood might pose an additional source of error.

Relationship between plasma ammonia concentration and beta-N-acetylhexosaminidase isoenzyme activities in liver cirrhosis.

Ammonia is known to increase the secretion of beta-N-acetylhexosaminidase (Hex) to the extracellular medium in cultured human fibroblasts and Hep G2 cells. We examined 35 patients with liver cirrhosis and the results revealed a significant increase for the plasma activities of total Hex and its isoenzymes Hex A and Hex B (p < 0.001). The partial correlations, with other biochemical markers of liver injury constant, between plasma ammonia concentration and the activity (r = 0.658) and the proportion in percentage of the Hex B isoenzyme (r = 0.692) were statistically significant (p < 0.001). The increased concentration of ammonia could explain, at least partially, an increased secretion of Hex B isoforms to the plasma in patients with liver disease.

Increased serum IgE in alcoholics: relationship with Th1/Th2 cytokine production by stimulated blood mononuclear cells.

BACKGROUND: Increased serum immunoglobulin (Ig) E values are frequently found in alcoholics. Cytokines produced by T-helper-2 (Th2) lymphocytes are required for IgE synthesis. Chronic alcoholism is associated with altered cytokine balance. This study analyzed the relationship between Th1 and Th2 cytokine production by stimulated peripheral blood mononuclear cells (PBMCs) and serum IgE levels, both in atopic and nonatopic alcoholics. METHODS: Twenty-five patients admitted to the hospital with alcohol withdrawal syndrome were included in the study. Five were classified as atopic and 20 as nonatopic by means of skin-prick tests. Interleukin-4 (IL-4), IL-10, IL-12, IL-13, and interferon gamma were measured in the supernatants of 48-hr cultures of PBMCs stimulated with phytohemagglutinin. Total serum IgE was measured by chemiluminescent enzyme immunoassay. Results were compared with those of 15 healthy controls (seven atopics and eight nonatopics). RESULTS: Total serum IgE concentrations were higher in alcoholics than in controls, in both atopic and nonatopic subjects. The ratio of IL-4 to interferon gamma production by phytohemagglutinin-stimulated PBMCs (as an approach to Th2/Th1 balance) was significantly lower in alcoholics than in healthy controls, both in the atopic and in the nonatopic group. No difference was observed regarding IL-10, IL-12, and IL-13 production between alcoholics and controls. No correlation was demonstrated between cytokine production and total serum IgE levels in any group. CONCLUSIONS: Increased total serum IgE is observed in alcoholics together with a paradoxically low ratio of Th2 to Th1 cytokine production by phytohemagglutinin-stimulated PBMCs. These findings are independent of the atopic status of patients.

Increased serum tissue polypeptide specific antigen (TPS) in alcoholics: a possible marker of alcoholic hepatitis.

BACKGROUND: Serum tissue polypeptide specific antigen (TPS) is widely used as a tumor proliferation marker. There is some evidence of an increase in serum TPS in benign liver diseases. The aim of the study was to evaluate serum TPS levels in alcoholics. METHODS: Seventy-seven alcoholics (64 men and 13 women) admitted to the hospital with ethanol withdrawal syndrome entered the study. Twenty-three patients were biopsied (12 of them had alcoholic hepatitis and 11 steatosis or fibrosteatosis). Serum TPS was determined by enzyme immunoassay in all cases. Results were compared with those of 24 healthy controls. RESULTS: Serum TPS levels were significantly increased in alcoholic patients compared with controls (median 365 units/liter and range 41-6400 units/liter versus median 79 units/liter and range 19-235 units/ liter, respectively, p < 0.0001). Seventeen alcoholics (22%) had a TPS value 10 times higher than the upper normal threshold level (> or = 1000 units/liter). Among alcoholics, serum TPS levels were higher in patients with alcoholic hepatitis than in those with steatosis or fibrosteatosis (median 1486 units/liter and range 176-5023 units/liter versus median 106 units/liter and range 41-221 units/liter, respectively, p = 0.0001), offering a better discriminant value for the diagnosis of alcoholic hepatitis than usual liver function parameters. Serum TPS values showed significant correlation with liver cell necrosis and Mallory's hyaline degeneration. TPS values decreased after alcohol abstinence during hospital admission. CONCLUSIONS: Serum TPS is frequently increased in alcoholics and may be a marker of alcoholic hepatitis. Specificity of this molecule as a tumor marker is limited in alcoholics.