Genes and Pathways Involved in the Progression of Malignant Pleural Mesothelioma: A Meta-analysis of Genome-Wide Expression Studies

Malignant pleural mesothelioma (MPM) is a rare and aggressive neoplasm of the pleural tissue that lines the lungs and is mainly associated with long latency from asbestos exposure. This tumor has no effective therapeutic opportunities nowadays and has a very low five-year survival rate. In this sense, identifying molecular events that trigger the development and progression of this tumor is highly important to establish new and potentially effective treatments. We conducted a meta-analysis of genome-wide expression studies publicly available at the Gene Expression Omnibus (GEO) and ArrayExpress databases. The differentially expressed genes (DEGs) were identified, and we performed functional enrichment analysis and protein-protein interaction networks (PPINs) to gain insight into the biological mechanisms underlying these genes. Additionally, we constructed survival prediction models for selected DEGs and predicted the minimum drug inhibition concentration of anticancer drugs for MPM. In total, 115 MPM tumor transcriptomes and 26 pleural tissue controls were analyzed. We identified 1046 upregulated DEGs in the MPM samples. Cellular signaling categories in tumor samples were associated with the TNF, PI3K-Akt, and AMPK pathways. The inflammatory response, regulation of cell migration, and regulation of angiogenesis were overrepresented biological processes. Expression of SOX17 and TACC1 were associated with reduced survival rates. This meta-analysis identified a list of DEGs in MPM tumors, cancer-related signaling pathways, and biological processes that were overrepresented in MPM samples. Some therapeutic targets to treat MPM are suggested, and the prognostic potential of key genes is shown.

Síndrome nefrótico secundario a podocitopatía en infección por SARS-COV2

Introducción: el síndrome respiratorio agudo severo inducido por coronavirus-2 (SARS-CoV-2) se caracteriza por la instalación de una afectación pulmonar. Sin embargo, existen reportes de afectación renal concomitante, con manifestaciones clínicas como hematuria, proteinuria y daño renal agudo. Objetivo: presentamos dos casos clínicos de síndrome nefrótico asociado a enfermedad por coronavirus (COVID-19). Presentación del caso: un paciente presentó evidencia histológica de cambios mínimos y fusión de pedicelos de podocitos en muestras histológicas evaluadas por microscopía electrónica. Discusión: la proteinuria en  COVID-19 puede ser secundaria a lesiones glomerulares y tubulares agudas, con un origen multifactorial: factores hemodinámicos, tormentas de citocinas, infecciones secundarias, nefrotoxicidad inducida por fármacos e infección viral directa de las células del túbulo proximal y podocitos. Esta última podría deberse a una infección directa por el virus debido al mayor tropismo renal de este. Conclusión: el presente informe presenta dos casos de síndrome nefrótico secundario a podocitopatía en pacientes con infección aguda por COVID-19.

Severe gastrointestinal injury associated with SARS-CoV-2 infection: Thrombosis or Inflammation?: A retrospective case series study

OBJECTIVES

Acute gastrointestinal injury (AGI) associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a low incidence of complications in patients admitted to the intensive care unit (ICU). Pathophysiological knowledge related to AGI is limited, as few studies have been published on this topic. Therefore, this study was carried out to identify the clinical and histopathological features of patients with SARS-CoV-2 infection and grade IV AGI.

METHODS

This is a retrospective case study of fifteen patients with SARS-CoV-2 infection and grade IV AGI who underwent emergency surgery.

RESULTS

This study revealed a mortality rate of 62.5%. The most frequent gastrointestinal symptoms were abdominal distension (100%) and increased gastric residual volume (93.3%). Distended bowel loops on plain abdominal radiography (90%) and intestinal pneumatosis on computed tomography (50%) were the most frequent imaging findings. Surgical exploration revealed intestinal ischemia (66.6%) and necrosis (46.6%), and histopathology showed ischemic and liquefactive necrosis with mixed inflammatory involvement and absence of thrombosis as the cause of AGI.

CONCLUSIONS

AGI associated with severe SARS-CoV-2 infection has a high mortality rate and poses a diagnostic challenge in the ICU. The complex pathophysiology and histopathological findings indicate an associated inflammatory phenomenon as the main alteration in the absence of thrombosis, as per the intestinal biopsies of the cases studied. Further clinical studies are required to gain a better understanding of this pathology.

The Effects of Chemotherapeutics on the Ovarian Cancer Microenvironment

High-grade serous ovarian cancer (HGSOC) is characterized by a complex and dynamic tumor microenvironment (TME) composed of cancer-associated fibroblasts (CAFs), immune cells, endothelial cells, and adipocytes. Although most approved therapies target cancer cells, a growing body of evidence suggests that chemotherapeutic agents have an important role in regulating the biology of the diverse cells that compose the TME. Understanding how non-transformed cells respond and adapt to established therapeutics is necessary to completely comprehend their action and develop novel therapeutics that interrupt undesired tumor-stroma interactions. Here, we review the effects of chemotherapeutic agents on normal cellular components of the host-derived TME focusing on CAFs. We concentrate on therapies used in the treatment of HGSOC and synthesize findings from studies focusing on other cancer types and benign tissues. Agents such as platinum derivatives, taxanes, and PARP inhibitors broadly affect the TME and promote or inhibit the pro-tumorigenic roles of CAFs by modifying the bidirectional cross-talk between tumor and stromal cells in the tumor organ. While most chemotherapy research focuses on cancer cells, these studies emphasize the need to consider all cell types within the tumor organ when evaluating chemotherapeutics.

POS1005 ASSESSMENT OF DAREA AND MODIFIED DAREA IN AN ARGENTINIAN-GUATEMALAN REACTIVE ARTHRITIS COHORT

Background:

Reactive Arthritis (ReA) is an inflammatory joint disease and, as in rheumatoid or psoriatic arthritis, composite indices are the most useful tools to measure disease activity. The Disease Activity Index for Reactive Arthritis (DAREA) is the only developed index for ReA, which requires a 66/68 joint count and CRP for its assessment, the latter being difficult to acquire in our setting. Therefore, we developed a simplified index, the modified DAREA (DAREAm), with a lower joint count and ESR for its evaluation.

Objectives:

1) To evaluate the DAREA and the DAREAm in a cohort of patients with diagnosis of ReA and post-infectious arthritis 2) To assess the correlation of the DAREA and DAREAm with several clinical variables, functional capacity and quality of life in a cohort of patients with ReA.

Methods:

Patients with diagnosis of ReA (Calin’79) and post-infectious arthritis were included. Demographic data were collected, patient´s pain and global assessment were evaluated through a visual analog scale (VAS) and a 3-point scale (no pain = 0, mild = 1, moderate = 2, severe = 3), physician´s global assessment, morning stiffness (MS) and VAS fatigue. Functional capacity was assessed by HAQ and quality of life according to EuroQol-5 dimensions (EQ-5D), and the activity indices DAS28, DAREA and DAREAm were calculated. Statistical analysis: a descriptive analysis of the variables and correlation between numerical variables with Spearman rank correlation were performed.

Results:

57 patients were included, 53 with diagnosis of ReA, the majority post urogenital (63%) and gastrointestinal (17%), and 4 with diagnosis of post-infectious arthritis. Fifty six percent were male, mean age: 40 years old (SD ± 14) and median ReA duration: 15 months (IQR 2-45). The number of painful and swollen joints in a 66/68 joint count showed a median of 2 (IQR 0-3) and 1 (IQR 1-2) respectively. Median VAS pain 43 (IQR 15-70), patient´s disease activity 40 (IQR 20-60) and physician´s 40 (IQR 20-60), MS 10 (IQR 0-50) and fatigue 30 (IQR 0-80). Median DAS28 3.6 (IQR 2.3-4.3), DAREA 7.4 (IQR 2.5-10.6), DAREAm 8.6 (IQR 4.6-12.7), HAQ 0.625 (IQR 0.125-1). The dimensions with the greatest compromise in the EQ-5D were pain/discomfort (63%) and anxiety/depression (51%), and the median VAS EQ-5D was 60 (IQR 32-80). DAREA correlated with DAREAm (rs= 0.89; p <0.001), DAS28 (rs= 0.84; p <0.001), medical VAS (rs= 0.60; p <0.001), MS (rs= 0, 50; p <0.001), HAQ (rs= 0.53; p <0.001), VAS fatigue (rs= 0.57; p <0.001) and mobility subscales of the EQ5D (rs= 0.56; p <0.001), pain/discomfort (rs= 0.49; p <0.001) and anxiety/depression (rs= 0.61; p <0.001). The DAREAm correlated with DAS28 (rs= 0.93; p <0.001), physician VAS (rs= 0.58; p <0.001), fatigue VAS (rs= 0.53; p <0.001), HAQ (rs= 0 .51; p <0.001) and the EQ5D subscales: mobility (rs= 0.64; p <0.001), pain/discomfort (rs= 0.56; p <0.001) and anxiety/depression (rs= 0.66; p <0.001)

Conclusion:

This is the first study that assess activity indices in a cohort of patients with ReA. The DAREAm demonstrated a very good correlation with both DAREA and DAS28. We encourage the use of this simplified index in daily practice to evaluate patients with ReA.

Disclosure of Interests:

None declared.

Influence of Sparger Type and Regime of Fluid on Biomass and Lipid Productivity of Chlorella vulgaris Culture in a Pilot Airlift Photobioreactor

The effect of different types of spargers and the influence of the air flow rate on biomass and lipids production by Chlorella vulgaris was evaluated. These data allowed correlation of the hydrodynamic behavior of the photobioreactor with the byproducts production. The hydrodynamic characterization was developed by determining the mixing time (tM), hold-up, and total volumetric mass transfer coefficient of CO2, kLa(CO2)T, at increasing air flow rates for three different spargers: star-shaped, cross-shaped and porous glass surface sparger. The hydrodynamic characterization showed that the tM decreased, while the hold-up values and the kLa(CO2)T increased as a result of the increment in the volumetric air flow rate between 5 to 17 L min–1. The highest biomass and lipid concentrations were determined at the higher aeration rate (20 L min–1), which was correlated with the lower tM, the higher hold-up and kLa(CO2)T values. Biomass and lipid production showed an inverse correlation. The highest biomass concentration (750 mg L–1) and the lowest lipid concentration (10 mg L–1) were measured with the star sparger. In contrast, when the lowest biomass concentration was obtained (240 mg L–1), the highest lipid concentration of 196 mg L–1 was measured with the glass sparger. The maximum biomass productivity values were determined at the lower aeration rate and the star sparger, with the minimum power per unit of volume, which could be useful for a cost-effective process.

Objective Sleep Assessments in Patients with Postural Tachycardia Syndrome using Overnight Polysomnograms

STUDY OBJECTIVES

Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness, and diminished quality of life. The study objective was to assess objective sleep quality in POTS patients using overnight polysomnography.

METHODS

We studied 16 patients with POTS and 15 healthy control subjects performing daytime autonomic functions tests and overnight polysomnography at the Vanderbilt Clinical Research Center.

RESULTS

There were no significant differences in the objective sleep parameters including sleep efficiency, sleep onset latency, wake time after sleep onset, REM latency, percentage of time spent in N1, N2, N3, and REM sleep, arousal index, apnea-hypopnea index, or periodic leg movement index in POTS patients as compared with healthy control subjects. There were significant negative correlations between sleep efficiency and the change in HR from supine to stand (rs = -0.527; p = 0.036).

CONCLUSIONS

POTS patients do not have significant differences in objective sleep parameters as compared to control subjects based on overnight polysomnograms. Activation of the sympathetic nervous system may contribute significantly to the hyper arousal state and worsening of subjective estimates of sleep quality as previously reported in POTS patients.

Understanding the placebo effect in clinical trials for postural tachycardia syndrome

Postural tachycardia syndrome (POTS) is characterized by excessive increases in heart rate (HR) upon standing. Previous studies have shown that standing HR decreases over time in POTS patients given placebo. We hypothesized that this reduction is due to cardiovascular physiological alteration, as opposed to psychological benefit from perceived therapy. To prospectively test this hypothesis, we examined the effects of an open-label 'no treatment' intervention (NoRx) compared with a patient-blinded placebo on standing HR in POTS patients. Twenty-one POTS patients participated in a randomized cross-over trial with oral placebo versus NoRx administered at 0900 h. Seated blood pressure (BP) and HR were measured at baseline and every hour for 4 h. Similarly, BP and HR were measured while patients stood for 10 min at these time points. Standing HR decreased significantly over time with both NoRx (112±13 and 103±16 b.p.m. at baseline and 4 h, respectively) and placebo (112±14 and 102±16 b.p.m. at baseline and 4 h, respectively; Ptime<0.001), but this effect was not different between interventions (Pdrug=0.771). Postural tachycardia syndrome patients have exaggerated orthostatic tachycardia in the morning that decreases over time with either placebo or NoRx interventions, suggesting this phenomenon is due to cardiovascular physiological variation. These data highlight the need for a placebo arm in haemodynamic clinical trials in POTS and may have important implications for the diagnosis of these patients.

Positive C4d in kidney transplantation biopsy: clinical impact

BACKGROUND

Deposition of C4d in peritubular capillaries of renal graft is normally associated with the presence of antibody-mediated rejection. The clinical impact of its presence in patients with renal transplant in Colombia is uncertain, as well as the association in acute rejection and the response to the management and survival of the graft. The aim of this study was to determine the risk of having positive C4d in biopsies of patients with episodes of acute cellular rejection.

METHODS

We retrospectively reviewed 226 biopsies of kidney transplantation, all of them with acute rejection and histopathological findings classified according to Banff criteria 2009 and performed between January 2005 and December 2012 for graft dysfunction. C4d staining was performed by immunohistochemistry.

RESULTS

C4d staining was positive in 25 of 226 biopsies. Rejection time in patients with positive C4d was 15 months in average vs 8 months with negative C4d.

CONCLUSIONS

With the use of a multivariate analysis, we found that the unique risk for C4d in our population was the positive panel reactive antibodies and elapsed time between transplant and the rejection (odds ratio: 2.12, P = .034) and that the other variables analyzed are not related to the expression of C4d.

Within herd transmission and evaluation of the performance of clinical and serological diagnosis of foot-and-mouth disease in partially immune cattle herds

The control of foot-and-mouth disease (FMD) in vaccinated populations relies upon surveillance activities such as clinical inspections (CI) and serological monitoring. New evidence to refine current surveillance guidelines has been provided by evaluating (1) the diagnostic performance of CI and serological tests for detection of FMD virus (FMDV) non-structural proteins (NSP), and (2) the within-herd transmission of the virus in partially immune cattle. Data came from 23 affected herds during an epidemic of FMDV type O in Bolivia, in 2007. All cattle (n=957) in these herds were clinically inspected and serum samples were collected one month after the last animal with clinical signs was detected. Samples were tested for the presence of antibodies against NSP using the PANAFTOSA 3ABC-ELISA test and a subset of samples were tested using the enzyme-linked immunoelectrotransfer blot assay (EITB). Data from clinical and serological diagnoses were analysed using a Bayesian model. The sensitivity Se and specificity Sp of the tests, as well as the prevalence and the within-herd reproduction ratio R of FMDV were estimated. In addition, risk factors for infection were identified. The Se of CI, the 3ABC-ELISA and the EITB tests were estimated to be 0.30, 0.88 and 0.96 respectively. The estimated Sp, in the same order, were 0.88, 0.93 and 0.97. The within-herd prevalence of infected animals ranged from 0.04 to 0.91 and R ranged from 1.02 to 2.68. It was observed that cattle coming from areas with high vaccination coverage had a lower risk of becoming infected than home-bred cattle from the affected herds, where vaccination coverage was thought to be low. Although these estimates come from herds kept under specific conditions, they provide a reference for future surveillance design and can inform simulation models for surveillance and control of FMD in similar cattle populations.

Estimation of sleep disturbances using wrist actigraphy in patients with postural tachycardia syndrome

STUDY OBJECTIVES

Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness and diminished quality of life. The study objective was to assess sleep quality in POTS patients using wrist actigraphy.

DESIGN

Prospective study with control group.

METHODS

Patients with POTS (n = 36) and healthy subjects (n = 36) completed a detailed sleep log and actigraphy for 7 days.

RESULTS

Compared with healthy subjects, POTS patients have more self-reported problems including days with restless sleep (53 ± 30% vs. 21 ± 20%; P<0.001) and tiredness (75 ± 23% vs. 39 ± 27%; P<0.001). Using actigraphy, POTS patients have lower sleep efficiency (73 ± 13% vs. 79 ± 6%; P = 0.01). Actigraphy determined sleep onset latency (SOL) did not vary significantly in the two groups, but subjective SOL was higher in POTS patient (56 ± 66 min vs. 1 3 ± 9 min; P = 0.001). In POTS patients, there was a significant correlation between subjective complaints of tiredness and actigraphic sleep efficiency (Rs = -0.36; R(2) = 0.15; P = 0.01), significant correlations between actigraphic SOL and upright norepinephrine levels (P = 0.040), and between wake after sleep onset and standing heart rate (P = 0.02).

CONCLUSIONS

POTS patients have more sleep-related symptoms and poor sleep efficiency. The pattern of subjective vs. objective SOL mismatch is suggestive of sleep-state misperception. High norepinephrine correlated with actigraphic SOL, and this activation of the stress system may contribute significantly to a hyperarousal state with consequent insomnia, poor mental and physical health in POTS patients.

[Colorectal surgery in patients over 65 years of age]

BACKGROUND

There is a limited functional reserve in patients over 65 years of age which is conducive to more frequent postoperative complications. Disease extension at the time of diagnosis (clinical stage) and complete tumor resection are two independent risk factors that have a direct influence on survival.

AIMS

To describe the factors that influence morbidity and mortality in patients over 65 years of age after colorectal surgery.

MATERIAL AND METHODS

A retrospective, observational, descriptive study was carried out within the time frame of January 2004 and December 2009 on 105 colon cancer patients after colorectal surgery. They were divided into two groups, one under 65 years of age and the other over 65 years of age, in order to compare preoperative comorbidity, as well as morbidity and mortality 30 days after surgery.

RESULTS

Of the 105 patient total (53,3%), 56 were ≤ 65 years of age. There were complications in 42,8% of the patients, and those of early and less severe presentation were the most frequent; late complications were more frequent in patients ≤ 65 vs > 65 years of age (16,0% vs 10,2%). Overweight (BMI > 25 kg/m(2)) was observed in 35,0% of the study population. Patients > 65 years of age had fewer comorbidities. The most common causes of reintervention were anastomosis dehiscence and postoperative hemorrhage. Mortality in the group was 6,6% and sepsis was the most frequent cause of death.

CONCLUSIONS

Colorectal surgery in patients over 65 years of age has an acceptable complication frequency and a low mortality rate. Our results suggest that patients older than 65 years of age be treated with the same prospects for cure as younger patients.

White plague-like coral disease in remote reefs of the Western Caribbean

The health of coral reef communities has been decreasing over the last 50 years, due the negative effects of human activities combined with other natural processes. We present documentation of a White Plague Disease (WPD) outbreak in the Serrana Bank, an isolated Western Caribbean atoll with presumably inexistent pollutant inputs from local human settlements. In addition, this study summarizes seven years of observations on diseased corals in the nearby island of San Andrés, which in contrast is one of the most populated islands of the Caribbean. There was a massive coral mortality in the atoll lagoon (14 degrees 27'53.24", 80 degrees 14'22.27" W, and 12m depth) due to WPD on May 4 of 2003. Seventeen species were found dead or largely affected by the disease. The information resulting from GPS and manta-tow transects revealed that approximately 5.8 ha of reticulate Montastraea spp. patch reefs were lethally affected by the disease in the atoll. On May 8 of the same year we observed and calculated a mean coral cover of 7.03% (SD +/- 2.44), a mean diseased coral tissue cover of 5.5% (SD +/- 1.1) and a 13.4% (SD +/- 8.05) of recently dead coral covered with a thin filamentous algae layer; approximately 73% of mortalities caused by the disease occurred before the end of the outbreak. A rough estimate of 18.9% in recent coral cover reduction can be attributed to WPD. This represents about 82% of the total coral cover decline since 1995. Semi-enclosed environments such as atoll lagoons and the reticulate patch-reefs of Montastraea spp. seem to be particularly vulnerable to this kind of coral disease, which constitute an alert to increase the monitoring of the same kind of atoll environments. The WPD has been present in the area of the nearby island of San Andrés at a low prevalence level, with sporadic increasing peaks of disease proliferation. The peaks observed during 1999 and 2004 comprised increases of 266% and 355% respectively, suggesting an alarming progression of the disease in this area. This study includes new information of the epizoolotiology of White Plague Disease and documents the permanent prevalence and progression of the WPD in the area of San Andres Island.

Recent dynamics and condition of coral reefs in the Colombian Caribbean

Long-term monitoring data provide a basis to recognize changes in coral reef communities and to implement appropriate management strategies. Unfortunately, coral reef dynamics have been poorly documented at any temporal scale in the Southern Caribbean. Through the "National Monitoring System of Coral Reefs in Colombia" (Spanish acronym: SIMAC), we assessed 32 permanent plots at different depth levels in six reefs areas of the Colombian Caribbean from 1998 to 2004. Temporal trends in coral and algal cover were evaluated by repeated measures ANOVA. The model included the effect of depth levels (a fixed effect), monitoring plots (a random effect) as a nested factor within depths, and time (repeated factor). We found high spatial variability in major benthic components. Overall means indicated that algae were the most abundant biotic component in nearly all areas, ranging from 30.3% at Rosario to 53.3% at San Andrés. Live coral cover varied considerably from 10.1% at Santa Marta up to 43.5% at Urabá. Coral and algae cover per se are not always accurate reef indicators and therefore they need supplementary information. Temporal analyses suggested relative stability of coral and algal cover along the study but the causes for the observed trends were rarely identified. A significant decrease (p = 0.042) in coral cover was only identified for some monitoring plots in Tayrona-time x plot (depth level) interaction, and importantly, few coral species explained this trend. Significant increase (p = 0.005) in algal cover was observed over time for most plots in Rosario. Temporal trajectories in algal cover were influenced by depth-significant time x depth interaction-in San Andrés (increase, p = 0.004) and Urabá (decrease, p = 0.027). Algae trends were mainly explained by changes in algal turfs. Monitoring programs must focus on the mechanisms mediating the changes, in particular those concerning coral recovery and reef resilience in the current context of climate change.

[Factors related to haemolysis in the extraction of blood samples]

The choice of a venous access system to provide safe blood collection and reliable analytical results for that sample is of paramount importance in any accident and emergency department. The objective of this study was to identify the factors associated with haemolysis in venous blood samples, where the variables studied were: type of venipuncture (needle and catheter), type of catheter (3 catheters of 3 different materials) and diameter of the catheter. The sample was obtained from all patients who required a blood test in the accident and emergencies department of the Virgen del Camino Hospital over 34 days, collected in 3 different periods (September-November), involving a total of 1.933 procedures. Positive haemolysis determined by laboratory technicians was found in 2% (7/348) of samples obtained by needle compared to 14% (222/1585) obtained by catheter. We observe an 8% (39/475) of haemolysis in the samples taken by protective Teflon catheter, 18% (77/426) by Protectiv plus polyurethane and 15% (106/684) by BD-Nexiva Vialone. The haemolysis index fell with an increase in the size of the catheter, those of 18G showing 13% (115/867) and those of 20G showing 15% (107/708). The combination of catheter type and size maintains the smallest percentages of haemolysis in Teflon catheters and high diameters of 18G with 6% (19/301), less than half the haemolysis of the polyurethane catheters and a third of that for Vialone catheters respectively.

[Distribution patterns and bioerosion of the sea urchin Centrostephanus coronatus (Diadematoida: Diadematidae), at the reef of Playa Blanca, Colombian Pacific]

Regular sea-urchins are one of the main bioeroding organisms affecting coral reefs around the world. The abundance, distribution and bioerosion rate of the sea-urchin Centrostephanus coronatus, were determined in different reef zones of Playa Blanca fringing reef (Gorgona Island, Colombian pacific coast) during 1997 and 1998. The erosion rates were determined calcinating the gut content of the sea-urchins to eliminate all organic components and preserve the inorganic portion of calcium carbonate. C. coronatus showed the highest densities towards the central zones of the reef (plain-crest and front) (12.4 ind/m2; range 0-48 ind/m2). The highest mean bioerosion rate was 0.103 kgCaCO3/m2/yr in the reef plain-crest (0-0.69 kgCaCO3/m2/yr). In the other zones, (back reef and reef front) the mean bioerosion rates were 0.071 (range 0-0.39) and 0.052 (range 0-0.31) kgCaCO3/m2/yr respectively. According to the present data, it can be seen that the destruction of coralline skeletons, produced in this reef by sea-urchins is rather low, compared with the abrasion caused by these organisms in other places of the world. However, the combined action of C. coronatus and other bioeroding organisms (borers and grazers). along with some adverse environmental factors to corals, can be causing a negative balance between normal processes of reef accretion-destruction in Gorgona Island reefs.

A base substitution in the interleukin-10 (IL-10) promoter between Sp1 and ets-1 binding sites is not associated with variation of IL-10 levels

Interleukin 10 (IL-10) may play an important anti-inflammatory and immunoregulatory role in asthma. In this study, we investigated the role of a C to A substitution at position -627 of the IL-10 promoter, located in a necessary transcriptional region, which contains a number of putative transcriptional binding sites. The -627 nucleotide position is itself flanked by Sp-1 and ets-1 binding sites. We studied the allele frequency in 53 unrelated subjects from an admixed Caucasian, Asian and Pacific Islander group with personal or family histories of asthma. The frequency of homozygous C/C, heterozygous C/A, and homozygous A/A alleles at position -627 was 0.28, 0.44 and 0.28, respectively. In vitro assays indicated no differences between the C/C and A/A forms in binding transcriptional factors, especially Sp-1 factor, or in promoter activity. Moreover, in this selected population, there was no association between the C to A substitution and serum IL-10 levels. The mean level of IL-10 serum was determined to be 3.87 +/- 1.23 pg/ml in subjects carrying the A/A genotype, 3.47 +/- 0.57 for C/C genotype and 3.13 +/- 0.41 for the heterozygous (C/A genotype). This requires confirmation by comparing to non-asthmatic subjects. We conclude that although the -627 A allele occurs frequently (50% of alleles) in this selected group, in vitro assays and serum IL-10 levels suggest that the -627C-->A substitution represents a silent or neutral variant in the IL-10 promoter.

A re-examination of the association of 'early pregnancy factor' activity with fractions of heterogeneous molecular weight distribution in pregnancy sera

The association of 'early pregnancy factor' ('EPF') activity in early pregnancy sera with multiple fractions of heterogeneous molecular mass was re-examined to test whether previously perplexing observations could be explained by a new multi-factorial model of the serum components required for this activity expression. Gel permeation fractionation of human pregnancy sera revealed 'EPF' activity associated with fractions containing components ranging in MW from < or = 1 kDa to > or = 500 kDa. A significant activity peak was observed eluting on the total volume (Vt) of the column, indicating the presence of active molecules of very low molecular mass. Multiple activity peaks were also observed in the macromolecular fractionation region ranging in apparent molecular weight from 12 kDa, through 25, 70 and 250 to > or = 500 kDa. Analysis of these fractions revealed that they all contained thioredoxin and active moieties of low molecular mass, with the latter probably directly associated with the former. Adsorption with specific anti-thioredoxin antibodies removed from these fractions the capacity to display 'EPF' activity. Further analyses revealed that in these fractions thioredoxin played a permissive role allowing the low molecular mass active moieties to express activity in the bioassay in the presence of otherwise counteracting substances. The results of these studies are consistent with the proposal that 'EPF' activity expression in pregnancy sera is due to the presence of a multi-factorial system in which thioredoxin plays an essential permissive role in concert with active moieties of low molecular mass.

Molecular mechanisms of the antihormonal and antiimplantation effects of norethisterone and its A-ring reduced metabolites

Norethisterone (NET) has been used as a contragestational postcoital agent. It is biotransformed to 5 alpha dihydro-NET (5 alpha-NET) and 3 beta,5 alpha tetrahydro-NET (3 beta,5 alpha-NET) in target tissues. The participation of these metabolites in NET effects is unknown. We have examined the antiimplantation and antiprogestational effects of NET and its metabolites, in adult mated female rabbits, by assessing the number of implantation sites and the expression products of the uteroglobin (UTG) gene in the uterus, and by comparing them with those of RU-486 and estradiol. Steroids were daily administered s.c. at several doses for 7 consecutive days, starting 24 hr after coitus. To assure that fertilization occurred in all animals, the presence of early pregnancy factor was determined. The results demonstrated that high doses (5 mg/kg) of NET reduced both implantation and the expression of the UTG gene. On the other hand, lower doses (1.5 mg/kg) of 5 alpha-NET produced an antiimplantation effect and suppressed UTG synthesis and its mRNA. These effects were similar to those of RU-486. At lower doses (1 mg/kg), both estradiol and the estrogenic metabolite 3 beta,5 alpha-NET were also effective in inhibiting implantation and UTG gene expression. The overall results suggest that NET metabolites exert antiimplantation and antiprogestational effects through their interaction with progesterone and estrogen receptors, and provide an explanation for the molecular mechanisms involved in the postcoital contraceptive action of NET.

The 'early pregnancy factor' revisited; the effect of ammonium sulfate on the capacity of pregnant mouse sera to express activity in the rosette inhibition assay

The effect of ammonium sulfate on the capacity of sera of pregnant animals to induce the expression of increased rosette inhibition titres in the rosette inhibition assay, that is, to express the so-called early pregnancy factor activity, was reinvestigated. The results show that the sera of pregnant mice contain low molecular mass (less than 1 kDa) moieties active in the rosette inhibition assay. Some of these moieties could be removed from the macromolecular components of sera by dialysis; however, most, or at least the most potent, of these molecules were shown to be associated with macromolecular components of the sera and were not removed by dialysis. Treatment of sera of pregnant mice with 40% ammonium sulfate released the bound low molecular mass moieties and these moieties partitioned into the supernatant fraction, whereas the macromolecular components to which they were bound partitioned into the pellet fraction. Extensive dialysis removed the low molecular mass active moieties from the supernatant fraction. The macromolecular components remaining in the supernatant retentate fraction obtained after extensive dialysis counteracted the action of the low molecular mass moieties in a dose-dependent manner in inducing increased rosette inhibition titres. However, macromolecular components in the extensively dialysed pellet fraction associated with the low molecular mass moieties in the absence of ammonium sulfate and modified their dose-response characteristics in the biological assay.(ABSTRACT TRUNCATED AT 250 WORDS)

A description of the basic system of components in pregnant mice sera responsible for 'early pregnancy factor' activity

The supernatant and pellet retentate fractions obtained from sera from pregnant mice by ammonium sulfate fractionation and extensive dialysis cannot alone induce increased rosette inhibition titres in the rosette inhibition assay. In combination, however, the mixtures can induce increased rosette inhibition titres mimicking the activity of pregnancy sera previously ascribed to the early pregnancy factor. The studies described herein demonstrated that the supernatant retentate fractions derived from sera of pregnant mice were functionally equivalent to a platelet-activating factor (PAF) or a serum stimulus because they stimulated the spleen cells used in the assay to produce active moieties and cooperated with pure thioredoxin in allowing for expression of activity. Conversely, the pellet retentate fractions obtained from sera of pregnant mice were shown to be functionally equivalent to thioredoxin in that they cooperated with a PAF stimulus to allow for the expression of increased rosette inhibition titres. The supernatant retentate fractions obtained from sera from male mice were found to be functionally equivalent to the corresponding supernatant retentate fractions obtained from sera from pregnant mice in stimulating the production of active moieties and in cooperating with thioredoxin or the pellet fractions derived from sera from pregnant mice in allowing for increased rosette inhibition titres. The pellet retentate fractions obtained from male mouse sera, however, were not functionally equivalent to either thioredoxin or the corresponding pellet retentate fractions obtained from pregnancy sera. Consideration of these data led to a basic description of the system of components in pregnancy sera which is responsible for the expression of early pregnancy factor activity.

Site-directed mutagenesis of human thioredoxin. Identification of cysteine 74 as critical to its function in the "early pregnancy factor" system

Thioredoxin has been identified as a key component of the "early pregnancy factor" system, a system of components present in pregnancy sera which expresses a lymphocyte modifying activity in an assay known as the rosette inhibition assay. Although thioredoxin alone is inactive, addition of thioredoxin to lymphocytes in combination with nonpregnancy sera or platelet-activating factor results in a positive response. We have changed several amino acids of human thioredoxin by site-directed mutagenesis to investigate the residues required for this cooperative function. Conversion of the two active site residues (cysteines 32 and 35) to serines results in a protein devoid of classical redox activity; however, this protein retained its ability to cooperate with non-pregnancy sera or platelet-activating factor in the rosette inhibition assay. Vertebrate thioredoxins contain an additional conserved pair of cysteine residues in the C-terminal portion of the protein. Changing both to serines resulted in no change in redox activity but completely abolished function in the rosette inhibition assay. Further study revealed this function was solely dependent on cysteine 74 as conversion of only cysteine 74 to serine abolished function, whereas replacement of only cysteine 70 with serine had no effect. The nonfunctional mutants counteracted the action of pregnancy serum in the assay strongly supporting the hypothesis that thioredoxin is an integral part of the early pregnancy factor system with residue cysteine 74 having an important role.

Identification of molecules involved in the 'early pregnancy factor' phenomenon

An isolated preparation from ovine placental extracts which was active in the rosette inhibition assay mimicking the activity of the so-called 'early pregnancy factor' (EPF) has been shown to contain a 12 kDa polypeptide which could be partially resolved from low-molecular-weight active moieties. N-terminal amino acid sequence analysis of the polypeptide indicated that it was ovine thioredoxin, an identification confirmed by isolation and complete sequence analysis of the corresponding cDNA. The cDNA for human thioredoxin was expressed in Escherichia coli and the recombinant protein isolated and purified. Pure recombinant thioredoxin alone did not induce the expression of increased rosette inhibition titres (RITs) when tested in the rosette inhibition assay; but, when tested in combination with cell stimuli such as platelet-activating factor (PAF) or serum, it allowed the expression of increased RITs where none was achieved in its absence. Thioredoxin acted in the assay to reverse a refractory state normally induced by these stimuli, allowing lipoxygenase-dependent moieties also induced by the stimuli to exert their effects, resulting in the expression of increased RITs. Antibodies to recombinant thioredoxin removed from pregnancy sera the capacity to induce increased RITs, i.e. to express EPF activity, thus establishing a role for thioredoxin or thioredoxin-like proteins and associated molecules in the mechanisms which allow pregnancy sera to induce increased RITs. Based on a consideration of these and other results, a new model for the study of the EPF phenomenon is presented and discussed.

Leukotrienes are active in the rosette inhibition assay mimicking the action of 'early pregnancy factor'

Lipoxygenase metabolites have been found to be active in the rosette inhibition assay by inducing increased rosette inhibition titres. Leukotrienes B4, C4, D4 and E4 were identified as possessing this activity. The cycloxygenase products, prostaglandins E2, D2 and F2 alpha had no such activity; however, prostaglandin E2 and to a lesser degree prostaglandin D2 could counteract the activity of the leukotrienes in this assay. The identified leukotrienes are the first characterised molecules known to display activity in the assay. In this respect they mimic the action of early pregnancy serum, an action ascribed to a so called 'early pregnancy factor'.

Partial characterization of the PAF-induced soluble factors which mimic the activity of 'early pregnancy factor'

Platelet-activating factor (PAF) stimulated mouse spleen cells to release soluble factors (termed S2 factors) which were capable of inducing increased rosette inhibition titres when applied to fresh mouse spleen cells in the rosette inhibition assay. In this ability the S2 factors mimic that of pregnancy serum, an action previously ascribed to 'early pregnancy factor'. The PAF-stimulated production of these S2 factors was not influenced by inhibitors of cyclooxygenase metabolism, but was completely inhibited by the lipoxygenase inhibitors, diethyl carbamazine and nordihydroguaiaretic acid. The S2 factors had a lipid-like character in that they were extractable in organic solvents. The calcium ionophore A23187 also stimulated the production of these factors which may well be products of the lipoxygenase pathway of arachidonic acid metabolism.

Platelet-activating factor and serum components from oestrous mice co-operate to mimic the activity of 'early pregnancy factor' in the rosette inhibition assay

When male mouse spleen cells were incubated with a combination of platelet activating factor (PAF, 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and sera from female mice in oestrus, the cells displayed a markedly increased rosette inhibition titre (RIT) when subsequently tested in the rosette inhibition assay. Neither PAF nor oestrous mouse sera alone could induce this effect, the combined action was required. Lyso-PAF could not substitute for the PAF, nor could male mouse sera nor the sera from females in dioestrus or metoestrus substitute for the oestrous mouse serum requirement. Pro-oestrous mouse sera could replace oestrous mouse sera but were less effective in their dose-responses. Studies on the mechanism of action of the PAF and oestrous mouse serum components suggested that the PAF stimulated the production and release of soluble factors (termed S2 factors) which by themselves could induce increased RIT values when applied to fresh spleen cells. The PAF-stimulated cell populations were rendered refractory to the action of these S2 factors and did not display increased RIT values, unless oestrous mouse serum was added. This serum acted to reverse the refractory state, allowing the S2 factors to exert their effect, and so cells treated with PAF and oestrous mouse serum displayed increased RIT values.

Early pregnancy factor: large scale isolation of rosette inhibition test-active polypeptides from ovine placental extracts

Protocols are described for the isolation of substantial (mg) amounts of a rosette inhibition test (RIT)-active polypeptide fraction from ovine placental extracts. The main component of the preparation is a 12K polypeptide which contains a highly reactive thiol group. Oxidation may occur during isolation with the result that the final preparation is a mixture of the 12K polypeptide and a 25K disulphide linked dimer. The highly reactive thiol group was found to be directly involved in activity expression since gentle reduction followed by iodoacetylation resulted in a complete loss of activity. Antisera were prepared and the antibodies removed all the RIT activity from fresh ovine placental extracts, indicating that molecules related to those in the isolated preparation were responsible for all the activity in crude extracts. The antibodies also removed all the RIT activity from ovine and murine pregnancy sera, obtained both before and after implantation. Since EPF is defined as an RIT activity detected in pregnancy serum, these results establish that EPF activity is due to molecules similar to those isolated from the placental extracts. The availability of the preparative protocol and antibodies should hasten the biochemical definition of the EPF phenomenon.

Platelet-activating factor induces the expression of early pregnancy factor activity in female mice

When synthetic platelet-activating factor (PAF, 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) was injected into mature female mice during dioestrus, pro-oestrus or oestrus, it induced the expression of early pregnancy factor (EPF) activity in the sera of these animals within 1 h of injection. The sera of similarly injected males, metoestrous or immature females did not display any EPF activity. The results suggest that embryo-derived PAF may be the ovum factor responsible for triggering the generation of serum EPF activity during the preimplantation stages of pregnancy.

Single calcium channels in native sarcoplasmic reticulum membranes from skeletal muscle

Electrical properties of native sarcoplasmic reticulum membranes from rabbit skeletal muscle were investigated using the patch-clamp technique. Bilayers were assembled at the tip of patch pipettes from monolayers formed at the air-water interface of sarcoplasmic reticulum membrane suspensions. The membranes were found to contain a spontaneously active cation channel of small conductance (5 pS in 200 mM CaCl2, symmetrical solutions) that was selective for Ca2+ and Ba2+. Between 50 and 200 mM CaCl2 (symmetrical) the increase in conductance as a function of [Ca2+] fit a hyperbola (K0.5, 83 mM, and gamma max, 7.9 pS) that extrapolated to a single-channel conductance of 0.5 pS at physiological Ca2+ levels. The channel opened in bursts followed by long silent periods of up to a minute. During a burst the channel fluctuated very rapidly with time constants in the millisecond range. The mean burst duration was voltage dependent, increasing from 1.8 s at a pipette voltage of +60 mV to 4.1 s at +80 mV. Over this range, burst frequency decreased with increasing voltage such that the fraction of time spent in the open state (fb) remained constant. Application of 1.6 mM caffeine resulted in activation of the channel that appeared as an increase in mean burst duration. In contrast, 50 microM dantrolene significantly decreased burst frequency, whereas 10 microM nitrendipine had no effect. The functional and pharmacological properties of this Ca2+ channel suggest that it may be important in mediating Ca2+ release from the sarcoplasmic reticulum during excitation-contraction coupling.

A comparative analysis of two methods for the study of alcohol intake in Mexico

Two different methodologies were studied in a semi-rural community in Mexico city to investigate alcohol-intake patterns and attitudes towards drinking and drunkenness. One of the methods consisted of a household survey. The other used the anthropological informant's technique. These methods were compared only at those points where were found similarities in the data collected. We conclude that both methods give comparable estimates of what goes on in the community. Nevertheless the informant method is cheaper, results are obtained in less time and the community members are engaged in this problem, thus permitting future action to be taken.