How heat waves, ozone and sunlight hours affect endocrine and metabolic diseases emergency admissions? A case study in the region of Madrid (Spain)

BACKGROUND

Studies which analyse the joint effect of acoustic or chemical air pollution variables and different meteorological variables on neuroendocrine disease are practically nonexistent. This study therefore sought to analyse the impact of air pollutants and environmental meteorological variables on daily unscheduled admissions due to endocrine and metabolic diseases in the Madrid Region from January 01, 2013 to December 31, 2018.

MATERIAL AND METHODS

We conducted a longitudinal, retrospective, ecological study of daily time series analysed by Poisson regression, with emergency neuroendocrine-disease admissions in the Madrid Region as the dependent variable. The independent variables were: mean daily concentrations of PM₁₀, PM_2.5, NO₂ and O₃; acoustic pollution; maximum and minimum daily temperatures; hours of sunlight; relative humidity; wind speed; and air pressure above sea level. Estimators of the statistically significant variables were used to calculate the relative risks (RRs).

RESULTS

A statistically significant association was found between the increase in temperatures in heat waves, RR: 1.123 95% CI (1.001-1.018), and the number of emergency admissions, making it the main risk factor. An association between a decrease in sunlight and an increase in hospital admissions, RR: 1.005 95% CI (1.002 1.008), was likewise observed. Similarly, ozone, in the form of mean daily concentrations in excess of 44 μg/m³, had an impact on admissions due to neuroendocrine disease, RR: 1.010 95% CI (1.007-1.035). The breakdown by sex showed that in the case of women, NO₂ was also a risk factor, RR: 1.021 95% CI (1.007-1.035).

CONCLUSION

The results obtained in this study serve to identify risk factors for this disease, such as extreme temperatures in heat waves, O₃ or NO₂. The robust association found between the decrease in sunlight and increase in hospital admissions due to neuroendocrine disease serves to spotlight an environmental factor which has received scant attention in public health until now.

Translation and Validation of the Spanish Version of the SARC-F Questionnaire to Assess Sarcopenia in Older People

OBJECTIVES

The revised European consensus on sarcopenia definition and diagnosis (EWGSOP2) includes the SARC-F questionnaire, the most valid and consistent sarcopenia screening tool, as the mandatory first step. Our aim was the translation, cross-cultural adaptation, and validation of the SARC-F questionnaire as a culturally-responsive Spanish-language version for the European population.

STUDY DESIGN

Cross-sectional descriptive study, applying the two-step WHO methodology for translation and cross-cultural adaptation of health questionnaires, and harmonization with the Mexican-Spanish version. European Union Geriatric Medicine Society recommendations for SARC-F validation in European languages were considered.

PARTICIPANTS

Outpatient clinics of a university hospital.

INCLUSION CRITERIA

stable, ambulatory (including aids), community-dwelling population ≥65 years old.

MAIN OUTCOME MEASURES

The self-reported 5-item SARC-F questionnaire was administered; scores ≥4 indicated sarcopenia. Sensitivity, specificity, accuracy-likelihood ratios, predictive values, and kappa statistics were calculated and consecutively compared with European Working Group on Sarcopenia in Older People (EWGSOP) and EWGSOP2 criteria.

RESULTS

This Spanish version, administered in an average 70s, has adequate internal consistency (Cronbach alpha=0.779). For the validation study, 90 (43.3%) of 208 potentially eligible subjects (81.4 ± 5.9 years old, 75.6% women) were included. SARC-F identified 51 (56.7%) subjects with sarcopenia and 39 (43.3%) without the disease. Prevalence was 17.8% per EWGSOP and 25.6% per EWGSOP2 (58% accuracy and fair agreement: sensitivity, 78.3%; specificity, 50.8%).

CONCLUSIONS

SARC-F is a feasible tool, suitable for bedside assessment in community-dwelling older patients. Wide diffusion of this culturally-responsible SARC-F Spanish version is expected as EWGSOP2 is adopted and sarcopenia assessment is broadly implemented in Spain.

Frailty Related Factors as Predictors of Functional Recovery in Geriatric Rehabilitation: The Sarcopenia And Function in Aging Rehabilitation (SAFARI) Multi-Centric study

BACKGROUND

Frailty-related characteristics, such as sarcopenia, malnutrition and cognitive impairment, are often overlooked, both in clinical practice and research, as potential contributors to functional recovery during geriatric rehabilitation.

OBJECTIVE

The aim of the study was to identify frailty-related characteristics associated with functional recovery in a cohort of post-orthopedic surgery and post-stroke older adults.

DESIGN

Multi-centric cohort study. Participanst and Settings: Patients over 65 years, admitted to three geriatric rehabilitation units, in Spain and Italy, after an orthopedic event or a stroke, from December 2014 to May 2016.

MEASUREMENTS

The Absolute Functional Gain (AFG) defined as the difference between Barthel Index score at discharge and at admission, and the Relative Functional Gain (RFG) that represents the percentage of recovery of the function lost due to the event, were selected as outcomes. Both outcomes were analyzed as continuous and dichotomous variables. Analyses were also stratified as diagnostic at admission.

RESULTS

We enrolled 459 patients (mean age±SD=80.75±8.21 years), 66.2% women, 69.5% with orthopedic conditions and with a length of stay of 28.8±9.1 days. Admission after a stroke (Odds Ratio=0.36, 95% Confidence Interval=0.22-0.59]) and a better functional status at admission (OR=0.96, 95% CI=0.94-0.97), were associated with a lower likelihood of AFG, while a better pre-event Barthel index (OR=1.03 for each point in score, 95% CI=1.01-1.04), being able to walk (OR=2.07, 95% CI=1.16-3.70), and a better cognitive status at admission (OR=1.05, 95% CI=1.01-1.09), were associated with a higher chance of AFG. Post-stroke patients with delirium at admission had a re-duced chance of AFG (OR=0.25, 95% CI=0.07-0.91]). Patients admitted after an ortho-pedic event with better pre-event functional status (OR=1.04, 95% CI=1.02-1.06) and able to walk at admission (OR=2.79, 95% CI=1.29-6.03]) had an increased chance of AFG. Additionally, in both diagnostics groups, a better handgrip strength increased the chance of RFG.

CONCLUSIONS

Among frailty-related variables, physical, cognitive and muscular function at admission could be relevant for functional improvement during geriatric reha-bilitation. If confirmed, this data might orient targeted interventions.

Yeasts isolated from figs (Ficus carica L.) as biocontrol agents of postharvest fruit diseases

Fresh fruit is highly perishable during postharvest life, mainly due to fungal growth. Thus, fungal control is an important goal for the fruit industry. In this work, a selection of antagonistic yeasts isolated from fig and breba crops were screened in vitro. The isolated yeasts were challenged with three moulds isolated from decayed figs and breba crops, identified as Penicillium expansum M639 and Cladosporium cladosporioides M310 and M624, and pathogenic moulds Botrytis cinerea CECT20518 and Monilia laxa CA1 from culture collections. Two yeast isolates, Hanseniaspora opuntiae L479 and Metschnikowia pulcherrima L672, were selected for their ability to inhibit the growth of aforementioned moulds. These yeasts reduced the radial growth of moulds on PDA by between 45.23% and 66.09%. Antagonistic activity was associated with the interaction of live yeast cells with moulds. M. pulcherrima L672 apparently parasitised C. cladosporioides isolates. In addition, challenges were assayed using wounded apples and nectarines, with significant reductions in percent infection and lesion size for all moulds tested. To our knowledge, this is the first report identifying H. opuntiae as an antagonist against different pathogenic moulds.

A novel antioxidant formulation designed to treat male infertility associated with oxidative stress: promising preclinical evidence from animal models

STUDY QUESTION

Does a novel antioxidant formulation designed to restore redox balance within the male reproductive tract, reduce sperm DNA damage and increase pregnancy rates in mouse models of sperm oxidative stress?

SUMMARY ANSWER

Oral administration of a novel antioxidant formulation significantly reduced sperm DNA damage in glutathione peroxidase 5 (GPX5), knockout mice and restored pregnancy rates to near-normal levels in mice subjected to scrotal heat stress.

WHAT IS KNOWN ALREADY

Animal and human studies have documented the adverse effect of sperm DNA damage on fertilization rates, embryo quality, miscarriage rates and the transfer of de novo mutations to offspring. Semen samples of infertile men are known to be deficient in several key antioxidants relative to their fertile counterparts. Antioxidants alone or in combination have demonstrated limited efficacy against sperm oxidative stress and DNA damage in numerous human clinical trials, however these studies have not been definitive and an optimum combination has remained elusive.

STUDY DESIGN, SIZE, DURATION

The efficacy of the antioxidant formulation was evaluated in two well-established mouse models of oxidative stress, scrotal heating and Gpx5 knockout (KO) mice, (n = 12 per experimental group), by two independent laboratories. Mice were provided the antioxidant product in their drinking water for 2-8 weeks and compared with control groups for sperm DNA damage and pregnancy rates.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In the Gpx5 KO model, oxidative DNA damage was monitored in spermatozoa by immunocytochemical detection of 8-hydroxy-2'-deoxyguanosine (8OHdG). In the scrotal heat stress model, male fertility was tested by partnering with three females for 5 days. The percentage of pregnant females, number of vaginal plugs, resorptions per litter, and litter size were recorded.

MAIN RESULTS AND ROLE OF CHANCE

Using immunocytochemical detection of 8OHdG as a biomarker of DNA oxidation, analysis of control mice revealed that around 30% of the sperm population was positively stained. This level increased to about 60% in transgenic mice deficient in the antioxidant enzyme, GPX5. Our results indicate that an 8 week pretreatment of Gpx5 KO mice with the antioxidant formulation provided complete protection of sperm DNA against oxidative damage. In mouse models of scrotal heat stress, only 35% (19/54) of female mice became pregnant resulting in 169 fetuses with 18% fetal resorption (30/169). This is in contrast to the antioxidant pretreated group where 74% (42/57) of female mice became pregnant, resulting in 427 fetuses with 9% fetal resorption (38/427). In both animal models the protection provided by the novel antioxidant was statistically significant (P < 0.01 for the reduction of 8OHdG in the spermatozoa of Gpx5 KO mice and P < 0.05 for increase in fertility in the scrotal heat stress model).

LIMITATIONS, REASONS FOR CAUTION

It was not possible to determine the exact level of antioxidant consumption for each mouse during the treatment period.

WIDER IMPLICATIONS OF THE FINDINGS

Recent clinical studies confirm moderate to severe sperm DNA damage in about 60% of all men visiting IVF centers and in about 80% of men diagnosed with idiopathic male infertility. Our results, if confirmed in humans, will impact clinical fertility practice because they support the concept of using an efficacious antioxidant supplementation as a preconception therapy, in order to optimize fertilization rates, help to maintain a healthy pregnancy and limit the mutational load carried by children.

STUDY FUNDING/COMPETING INTERESTS

The study was funded by the Clermont Université and the University of Madrid. P.G. is the Managing Director of CellOxess LLC, which has a commercial interest in the detection and resolution of oxidative stress. A.M. and A.P. are employees of CellOxess, LLC. J.R.D., A.G.-A. and R.J.A. are honorary members of the CellOxess advisory board.

Columnar and surface aerosol load over the Iberian Peninsula establishing annual cycles, trends, and relationships in five geographical sectors

The study of atmospheric aerosol load over the Iberian Peninsula (IP) under a climatological perspective is accomplished by means of PM10 and AOD440 nm measurements from EMEP and AERONET networks, respectively, in the period 2000-2013. The PM10 annual cycles in five Iberian sectors show a main maximum in summer and a secondary maximum in spring, which is only observed in the southern area for the AOD climatology. The characteristics of PM10-AOD annual cycles of each geographical sector are explained by the different climatology of the air mass origins and their apportioning. The two magnitudes are correlated with a factor ranging between 20 and 90 depending on the sector. The temporal evolution of the aerosol load has shown a notable decrease in the IP since the 1980s. Statistically significant trends are obtained in the Northeastern sector with a reduction of 26% (period 1985-2000) for the total suspended particles, which continues for the PM10 data with a value of 35% per decade (2001-2013), and also in the whole column, 61% per decade in the AOD440 nm (2004-2013).

Sex-specific embryonic origin of postnatal phenotypic variability

Preimplantation developmental plasticity has evolved in order to offer the best chances of survival under changing environments. Conversely, environmental conditions experienced in early life can dramatically influence neonatal and adult biology, which may result in detrimental long-term effects. Several studies have shown that small size at birth, which is associated with a greater risk of metabolic syndrome, is largely determined before the formation of the blastocysts because 70%–80% of variation in bodyweight at birth has neither a genetic nor environmental component. In addition, it has been reported that adult bodyweight is programmed by energy-dependent process during the pronuclear stage in the mouse. Although the early embryo has a high developmental plasticity and adapts and survives to adverse environmental conditions, this adaptation may have adverse consequences and there is strong evidence that in vitro culture can be a risk factor for abnormal fetal outcomes in animals systems, with growing data suggesting that a similar link may be apparent for humans. In this context, male and female preimplantation embryos display sex-specific transcriptional and epigenetic regulation, which, in the case of bovine blastocysts, expands to one-third of the transcripts detected through microarray analysis. This sex-specific bias may convert the otherwise buffered stochastic variability in developmental networks in a sex-determined response to the environmental hazard. It has been widely reported that environment can affect preimplantation development in a sex-specific manner, resulting in either a short-term sex ratio adjustment or in long-term sex-specific effects on adult health. The present article reviews current knowledge about the natural phenotypic variation caused by epigenetic mechanisms and the mechanisms modulating sex-specific changes in phenotype during early embryo development resulting in sex ratio adjustments or detrimental sex-specific consequences for adult health. Understanding the natural embryo sexual dimorphism for programming trajectories will help understand the early mechanisms of response to environmental insults.

Blood glucose control and quality of health care in non-insulin-treated patients with Type 2 diabetes in Spain: a retrospective and cross-sectional observational study

AIMS

To assess blood glucose control and quality of health care provided to non-insulin-treated patients with Type 2 diabetes mellitus in routine clinical practice in Spain.

METHODS

In this observational, retrospective, cross-sectional study, patients were grouped as either having good or suboptimal blood glucose control according to International Diabetes Federation or American Diabetes Association HbA(1c) goals. Clinical and socio-demographic data and compliance with the main standard level of care recommendations of the International Diabetes Federation were recorded during a routine visit. Correlates of glucose control were analysed by logistic regression.

RESULTS

Many patients were grouped as having suboptimal control under International Diabetes Federation (61.9%) or American Diabetes Association (45.0%) criteria. The mean number of accomplished International Diabetes Federation recommendations (7.3 out of 11) was higher for endocrinologists (than for internists or primary care physicians), and significantly more patients under their care were in the good glucose control group (than with primary care physicians). More recommendations were associated with blood glucose control using International Diabetes Federation than American Diabetes Association criteria, demanding higher quality of health care for achieving stricter goals. Some recommendations were poorly observed, particularly those concerning patients' education on diabetes, the prompt prescription of effective treatments and monitoring of complications. Diabetes complications were associated with being in the suboptimal control group. Patients' education on diabetes and HbA(1c) monitoring were associated with being in the good control group.

CONCLUSIONS

These results demonstrate the need for improvement in the management of patients with non-insulin-treated Type 2 diabetes in actual clinical practice in Spain. Such improvement would entail a stricter adherence to International Diabetes Federation recommendations.

Single- and multi-analyte determination of gonadotropic hormones in urine by Surface Plasmon Resonance immunoassay

Single- and multi-analyte detection of two gonadotropic hormones (follicle stimulating hormone (hFSH) and luteinizing hormone (hLH)) was achieved by a Surface Plasmon Resonance (SPR) immunoassay on untreated human urine samples. Multi-analyte detection was accomplished using two alternative formats which are based in the individual or simultaneous immobilization of the hormones on the sensor surface. The lowest detection limit for both hormones in urine was found to be 1 ng mL(-1), which in international units (IU) in terms of the World Health Organization (WHO) standards represents 8 mIU mL(-1) of hLH and 14 mIU mL(-1) of hFSH, respectively. The reliability of the assay was demonstrated by intra- and inter-assay variabilities < 6%, chip-to-chip variabilities < 5%, recoveries in the range of 80-120% and stability of the sensor response through more than 100 measurements. The sensitivity of this biosensing methodology renders it in a useful technique for the diagnosis of reproductive disorders, as well as for fertility monitoring.

Epidemiological characteristics of pregnancy, delivery, and birth outcome in women with multiple sclerosis in Argentina (EMEMAR study)

Background

The influence of pregnancy on Multiple Sclerosis (MS) has been extensively studied but such influence on Latin American women with MS has not been characterized. Our objective was to describe the course of pregnancy and birth outcome in Argentinean MS patients and the evolution of MS during pregnancy and after delivery.

Method

We used a retrospective design in eight MS centers in Argentina and administered a survey to women with definite MS (Mc Donald) with pregnancies during or after MS onset. We contacted 355 women of which 81 met inclusion criteria. We recorded 141 pregnancies.

Results

Involuntary abortion was observed in 16% of pregnancies (95% CI = 10–23). Thirty five women received immunomodulatory therapy (IMT) before 42 pregnancies. Twenty three (55%) out of 42 pregnancies were exposed to IMT. The mean time of IMT discontinuation before conception in 19 (45.2%) pregnancies without exposure, was 104 days (95% CI = 61.0–147.0). There were 103 deliveries: 79% full term. Birth defects were detected in 19% of pregnancies exposed to IMT (95% CI = 4–46) and in 2% of non-exposed (95% CI = 0.3–8.0). The mean relapse rate was: pre-pregnancy year: 0.22 (95% CI = 0.12–0.32); pregnancy: 0.31 in 1st (95% CI = 0.10–0.52), 0.19 (95% CI = 0.03–0.36) in 2nd, and 0.04 in 3rd trimester (95% CI = –0.04–0.12); 1st trimester post delivery: 0.82 (95% CI = 0.42–1.22).

Conclusion

We observed a higher rate of birth defects among infants exposed to immunomodulators in utero than those not exposed. The reduction in MS relapses during 2nd and 3rd trimester of pregnancy and its increase during postpartum is consistent with previous reports.

Determination of human growth hormone in human serum samples by surface plasmon resonance immunoassay

A surface plasmon resonance immunoassay has been developed to determine human growth hormone (hGH) directly and without pre-treatment in human serum samples. A binding inhibition immunoassay was employed. Antibody concentration, assay buffer and regeneration solution have been optimized in order to reach the best performance and the lower non-specific binding of the matrix components to the sensor surface. The lowest detection limit was 6 ng/mL, with a working range covering the physiological range. Reproducibility of the assay was excellent with both intra-assay and inter-assay relative standard deviations <5%, while a variation of 2.19% was obtained employing different sensor chips. Reutilization of the sensor surface allows its continuous use over 50 measurements with a signal drop <20%. The SPR immunoassay results were validated using enzyme-linked immunosorbent assay (ELISA) showing an excellent correlation (R(2)=0.985). A portable and fully automated system (Sensia SL) was employed in this work. This is the first SPR biosensor assay capable of detecting relevant concentrations of a clinical analyte in serum. This study shows the potentials of this device as a diagnostic tool for the detection of multiple clinical analytes.

[New targets for new anti-herpes drugs]

Although infections are often subclinical, herpes simplex virus (HSV) can cause mild to severe diseases, especially in immunocompromised patients. There are few drugs licensed for the treatment of HSV infections. Most target the viral DNA polymerase, such as acyclovir that remains the reference treatment some thirty years after its discovery! Extensive clinical use of this drug has led to the emergence of resistant strains, mainly in immunocompromised patients, these infections can be managed with only two drugs, foscarnet and cidofovir, both much more toxic than acyclovir. This highlights the crucial need for the development of new anti-herpes drugs that can inhibit infection by both wild-type viruses and drug-resistant strains. Over the last few years, significant efforts have been made to set up a range of strategies for the identification of potential new antiviral drugs. One alternative is to develop drugs with different mechanisms of action. The present article reviews potential viral and cellular targets that are now known to be involved in HSV multiplication and for which specific inhibitors with anti-HSV activity, at least in cell culture, have been identified. These drugs inhibit viral proteins involved in viral replication (DNA polymerase, ribonucleotide reductase or helicase-primase complex). Other drugs acting on cellular proteins needed for viral replication have also been described; these drugs are targetting cyclin-dependent kinases or the polyamine biosynthetic pathway.

On-line determination of 3,5,6-trichloro-2-pyridinol in human urine samples by surface plasmon resonance immunosensing

An immunochemical method for the analysis of 3,5,6-trichloro-2-pyridinol (TCP), a major urinary metabolite of chlorpyrifos, is developed using a surface plasmon resonance (SPR)-based biosensor. The stability of the assay was assessed by covalently linking the analyte derivative to a thin, gold-modified sensor surface. For optimization of analyte derivative immobilization, sensor chips were activated via alkanethiol monolayers with terminal amine or carboxyl groups. Binding inhibition tests were performed in untreated urine samples and compared to those obtained in distilled water and PBS was used as control. In all cases, similar detection limits, at the micrograms per litre level (0.1-0.24 microg L(-1)), were attained for TCP assays independently of the dilution buffer. Reproducibility of measurements was studied throughout more than 130 regeneration cycles, which allowed the repeated use of the same immunosensor surface without significant variation of the SPR signal. All measurements were developed in real-time in only 10 min, using a SPR portable system. The device could be applied as a valuable analytical method to both environmental screening and clinic diagnostics.

Optical immunosensor for fast and sensitive detection of DDT and related compounds in river water samples

A surface plasmon resonance (SPR) based immunosensor has been developed for the monitoring of environmentally persistent pollutants like DDT, its metabolites and analogues in real water samples. A reusable immunosurface is provided via the covalent attachment of the analyte derivative to a self-assembled alkanethiol monolayer formed onto the SPR gold-thin layer. The regeneration of the sensor surface allowed the performance of 270 assay cycles within an analysis time of 20 min for each assay cycle. Immunoassays based on a binding inhibition format were performed by using two monoclonal antibodies (MAbs) with different selectivity. Low limits of detection (LODs), in the sub-nanogram per litre range, were attained for DDT-selective (15 ng L-1) and DDT group-selective immunoassays (31 ng L-1). Both assays were carried out in spiked river water samples without significant effect of the matrix. SPR measurements were validated using gas-chromatography-mass spectrometry. The comparison between methods was in good agreement showing an excellent correlation coefficient (r2=0.995). The SPR analysis of DDT proved to be three times more sensitive than colorimetric ELISAs without the need of labelling and a much lower time of response. Our SPR biosensor portable platform (beta-SPR) is already commercialised by the company SENSIA, S.L. (Spain).

Multi-analyte SPR immunoassays for environmental biosensing of pesticides

Multi-analyte detection of environmentally relevant pesticides is performed by using a two-channelled surface plasmon resonance (SPR) biosensor. The special design of the SPR instrument allows the determination of several analytes (DDT, chlorpyrifos and carbaryl) via different immobilization formats. First, simultaneous pesticide monitoring is possible by flowing chlorpyrifos, carbaryl or DDT samples separately over each channel of the SPR system, wherein their corresponding recognition element was previously immobilized. The second approach is based on the multiple and combined immobilization of several analyte recognition elements on the sensing surface of one individual flow cell. In this format, the analysis time for all three pesticides varied from 40 to 60 min depending on the number of regeneration cycles. In most cases, similar detection limits were attained for the target analyte irrespective of the assay format, with sensitivity values at the nanogram per litre level (18-50 ng L(-1)). The assay reproducibility was proved through the repeated use of the same sensor surface for over more than 200 assay cycles, whereas the absence of biosensor response to non-related analytes showed the specificity and reliability of the analysis. The SPR instrument, including optics, electronics and microfluidics, is already commercialised by the company SENSIA, SL.

Determination of carbaryl in natural water samples by a surface plasmon resonance flow-through immunosensor

The analysis of carbaryl in natural water samples was accomplished using a portable immunosensor based on surface plasmon resonance (SPR) technology. The assay was based on a binding inhibition immunoassay format with the analyte derivative covalently immobilized on the sensor surface. An alkanethiol self-assembled monolayer (SAM) was formed onto the gold-coated sensor surface to allow the reusability of the same sensing surface during 220 regeneration cycles. Reproducibility was evaluated by performing three independent assays in triplicate on 3 different days. The batch-assay variability was also calculated using three different gold-coated sensor surfaces. The intra- and inter-day relative standard deviation were 8.6 and 15.3%, respectively, whilst a variation of 7.4% in assay sensitivity was obtained by employing different sensor chips. The lowest detection limit, calculated as the concentration providing a 10% decrease of the blank signal, was of 1.38 microg L(-1). Matrix effects were also evaluated in different water types, showing I50 values (carbaryl concentrations that produced a 50% decrease of the blank signal) within the range of carbaryl standard curves in distilled water (2.78-3.55 microg L(-1)). The carbaryl immunoassay performance was validated with respect to conventional high-performance liquid chromatography-mass spectrometry (HPLC-MS). The correlation between methods was in good agreement (r2 = 0.998, 0.999 and 0.999) for the three types of natural water samples tested. A complete assay cycle, including regeneration, is accomplished in 20 min. All measurements were carried out with the SPR sensor system (beta-SPR) commercialised by the company SENSIA, SL (Spain). The small size and low-time of response of the beta-SPR platform would allow its utilization in real contaminated locations.

Highly sensitive detection of biomolecules with the magneto-optic surface-plasmon-resonance sensor

The characteristics of a novel magneto-optic surface-plasmon-resonance (MOSPR) sensor and its use for the detection of biomolecules are presented. This physical transduction principle is based on the combination of the magneto-optic activity of magnetic materials and a surface-plasmon resonance of metallic layers. Such a combination can produce a sharp enhancement of the magneto-optic effects that strongly depends on the optical properties of the surrounding medium, allowing its use for biosensing applications. Experimental characterizations of the MOSPR sensor have shown an increase in the limit of detection by a factor of 3 in changes of refractive index and in the adsorption of biomolecules compared with standard sensors. Optimization of the metallic layers and the experimental setup could result in an improvement of the limit of detection by as much as 1 order of magnitude.

Nanomechanics of the formation of DNA self-assembled monolayers and hybridization on microcantilevers

Biomolecular interactions over the surface of a microcantilever can produce its bending motion via changes of the surface stress, which is referred to nanomechanical response. Here, we have studied the interaction forces responsible for the bending motion during the formation of a self-assembled monolayer of thiolated 27-mer single-stranded DNA on the gold-coated side of a microcantilever and during the subsequent hybridization with the complementary nucleic acid. The immobilization of the single-stranded DNA probe gives a mean surface stress of 25 mN/m and a mean bending of 23 nm for microcantilevers with a length and thickness of about 200 microm and 0.8 microm, respectively. The hybridization with the complementary sequence could not be inferred from the nanomechanical response. The nanomechanical response was compared with data from well-established techniques such as surface plasmon resonance and radiolabeling, to determine the surface coverage and study the intermolecular forces between neighboring DNA molecules anchored to the microcantilever surface. From both techniques, an immobilization surface density of 3 x 10(12) molecules/cm(2) and a hybridization efficiency of 40% were determined. More importantly, label-free hybridization was clearly detected in the same conditions with a conventional sensor based on surface plasmon resonance. The results imply that the nanomechanical signal during the immobilization process arises mainly from the covalent attachment to the gold surface, and the interchain interactions between neighboring DNA molecules are weak, producing an undetectable surface stress. We conclude that detection of nucleic acid hybridization with nanomechanical sensors requires reference cantilevers to remove nonspecific signals, more sensitive microcantilever geometries, and immobilization chemistries specially addressed to enhance the surface stress variations.

Infections in diabetic foot ulcers

Foot ulcers and infections are common in diabetic patients. A 30-month-long descriptive study was conducted in our hospital in which we analyzed microbiological isolates of all patients admitted with diabetic foot infections. The predominant flora identified were Staphylococcus aureus and coagulase-negative Staphylococcus, followed by Enterococcus spp., Streptococcus spp., and enterobacteriaceaes. In 27 positive cultures (42%) polymicrobial flora were found. There were only 5% anaerobic bacteria. There appears to be a relationship between the sample collection system and microbiological isolates.

Reduction of the cesarean delivery rate in Ecuador

OBJECTIVE

This quasi-experimental study tested a method to safely reduce the rate of cesarean delivery in Ecuador.

METHOD

Hospital policy was modified to provide co-management for cesarean candidates at the major maternity hospital in Quito. Cesarean rates before (n=14743) and after (n=12351) the intervention were compared by chi-square and multiple logistic regression with other major maternity hospitals (before, n=12514; after, n=9590). Characteristics of cesarean candidates who had vaginal or cesarean deliveries in the intervention hospital were compared by chi-square (n=1584).

RESULT

Cesarean rates declined by 4.5% (P<0.001) in the intervention hospital. A smaller (2.1%, P<0.01) reduction occurred in the other major public hospital in Quito where students of the co-principal investigator attempted to reduce cesarean delivery. Cesarean rates were unchanged in the public maternity hospitals of other major cities.

CONCLUSION

Case co-management, a simple, locally appropriate, and inexpensive intervention, safely reduced surgical delivery, hospital stay and cost of care.

Differential actions of the dopamine agonist bromocriptine on growth of SMtTW tumors exhibiting a prolactin and/or a somatotroph cell phenotype: relation to dopamine D2 receptor expression

Dopamine (Da) and Da agonists are known to inhibit secretion and proliferation of normal and tumoral PRL cells, through receptors of D2 subtype. Because of the lack of an experimental model, the relationship between bromocriptine (BR) sensitivity and D2 receptor expression is poorly documented. Such a relationship was analyzed using five lineages of spontaneous transplantable rat pituitary tumors (SMtTW) exhibiting different PRL/GH phenotypes. From plasma PRL and GH concentrations of rats bearing the tumors and tumor messenger RNA contents, tumors were classified as PRL (SMtTW2), somatotroph (SMtTW10), or somatomammotroph (SMtTW5) tumors. Two lineages (SMtTW3 and SMtTW4) represented variants producing PRL and GH but with a high predominance of PRL. With the exception of SMtTW4 tumors, which were malignant, all the tumors were benign and differed in their growth rate. Hormone production and growth of tumors with a PRL or a somatomammotroph phenotype were reduced by about 90% under BR treatment, whereas somatotroph tumors and the PRL malignant tumors were totally insensitive to BR. D2 receptor messenger RNA was present in all BR-sensitive tumors and was not detected in BR-resistant tumors. In conclusion, using five lineages of SMtTW tumors that are representative of the most frequent tumors encountered in human pituitary pathology, we found a full concordance between tumor responses to BR and the expression of D2 receptor by the tumors. The identification of a tumor lineage with a malignant phenotype, secreting high amounts of PRL and presenting a resistance to BR, supports the idea that Da-resistant prolactinomas are aggressive tumors.

Cell-to-cell communication in the anterior pituitary: evidence for gap junction-mediated exchanges between endocrine cells and folliculostellate cells

The ability of rat anterior pituitary cells to communicate through gap junctions (GJ) was studied using a fluorescent molecule, Lucifer Yellow (LY), which freely passes through GJ channels. The probe was introduced into the cell cytoplasm by using either the cut-end loading method on intact tissue, or cell microinjection on cultured cells. The identification of communicating cells was performed by immunofluorescence labeling of specific hormones in endocrine cells and of S100 protein in folliculostellate (FS) cells. Rat anterior pituitary cells in their physiological organization, i.e. in the intact tissue, exhibited a high level of coupling through GJ. LY-labeled cells were found up to 300-microns apart from its site of introduction. The communicating cells were primarily PRL cells, GH cells, and FS cells. Only a few LH, TSH, and ACTH cells were labeled with LY. Anterior pituitary cells, isolated from the rat tissue by mild protease treatment and cultured for 3 days, reestablished functional GJ as demonstrated by microinjection of LY into individual cells. By immunolabeling of specific hormones and/or S100 protein, we found a GJ coupling between FS cells, and between FS cells and endocrine cells, including PRL cells. The communication between FS cells was by far the most frequent. In conclusion, we demonstrate the presence of functional GJ between anterior pituitary cells of the same type and between anterior pituitary cells having distinct differentiated functions.

Cyclic guanosine 3',5' monophosphate concentrations in pre-eclampsia: effects of hydralazine

OBJECTIVE

To elucidate the role of the L-arginine:nitric oxide pathway in pregnancy and pre-eclampsia.

PARTICIPANTS

Pregnant women (nulliparous, age <25 years). Normotensive pregnancy (n=22) was defined when blood pressure remained at levels of <120/80 mmHg and there was no proteinuria. Women with pre-eclampsia (n=22) had blood pressure measurements of >140/90 mmHg and proteinuria of >300 mg/l. Nonpregnant normotensive women (n=22) were studied as controls.

STUDY DESIGN

Blood samples were taken for measurements of ionised calcium, atrial natriuretic factor, cyclic guanosine 3'5' monophosphate (GMP),arginine and asymmetric dimethylarginine. Urine samples were collected for determination of cyclic GMP excretion. Cyclic GMP concentrations were also determined in 12 women with severe pre-eclampsia before and after treatment with hydralazine.

RESULTS

L-arginine, asymmetric dimethylarginine and atrial natriuretic factor were not different in any group. Cyclic GMP concentrations in plasma [0.94 (SD 0.23) nM] as well as in urine [50.1 (SD 15.7) microM] were increased significantly (P<0.05) in normal pregnancy compared to nonpregnant controls [plasma mean 0.46 (SD 0.12) nM and urine mean 18.4 (SD 10.3) microM], but not in the pre-eclampsia group [plasma mean 0.48 (SD 0.10) nM and urine mean 24.1 (SD 14.5) microM]. Concentrations of cyclic GMP in plasma and urine increased significantly (P<0.05) in women treated with hydralazine.

CONCLUSIONS

The differences in cyclic GMP concentrations may reflect differences in nitric oxide production. Hydralazine increases cyclic GMP concentrations in severely pre-eclamptic women. This action could explain the antihypertensive effect of hydralazine.