Short-term effects of tropospheric ozone and other environmental factors on emergency admissions due to pregnancy complications: A time-series analysis in the Madrid Region

Air pollution has been linked to adverse neonatal outcomes, mainly in the case of prolonged exposures. This study focuses on the short-term effects on maternal health. We conducted a retrospective ecological time-series study in the Madrid Region covering the period 2013-2018. The independent variables were mean daily concentrations of tropospheric ozone (O3), particulate matter (PM10/PM2.5) and nitrogen dioxide (NO2), as well as noise levels. The dependent variables were daily emergency hospital admissions due to complications in pregnancy, childbirth and the puerperium. Poisson generalised linear regression models were fitted to quantify the relative and attributable risks, controlling for trend, seasonality, the autoregressive nature of the series, and a number of meteorological factors. There were 318 069 emergency hospital admissions due to obstetric complications across the 2191 days of study. Of this total: 13 164 (95%CI: 9930-16 398) admissions were attributable to exposure to O3, the only pollutant to show a statistically significant (p < 0.05) association with admissions due to hypertensive disorders; and 10 575 (95%CI: 3573-17 566) admissions were attributable to daytime noise levels, while admissions due to hyperemesis gravidarum and vomiting were related to exposure to night noise. Other pollutants which also displayed statistically significant associations were: NO2 concentrations, with admissions due to vomiting and preterm labour; PM10 concentrations, with premature rupture of membranes: and PM2.5 concentrations, with total complications. Exposure to a range of air pollutants, and ozone in particular, is associated with a higher number of emergency hospital admissions due to gestational complications. Hence, surveillance of environmental effects on maternal health should be intensified, and plans and strategies to minimise these should be drawn up.

Short-term impact of noise, other air pollutants and meteorological factors on emergency hospital mental health admissions in the Madrid region

BACKGROUND

A number of environmental factors, such as air pollution, noise in urbanised settings and meteorological-type variables, may give rise to important effects on human health. In recent years, many studies have confirmed the relation between various mental disorders and these factors, with a possible impact on the increase in emergency hospital admissions due to these causes. The aim of this study was to analyse the impact of a range of environmental factors on daily emergency hospital admissions due to mental disorders in the Madrid Autonomous Region (MAR), across the period 2013-2018.

METHODOLOGY

Longitudinal ecological time series study analysed by Generalised Linear Models with Poisson regression, with the dependent variable being daily Emergency Hospital Mental Health Admissions (EHMHA) in the MAR, and the independent variable being mean daily concentrations of chemical pollutants, noise levels and meteorological variables.

RESULTS

EHMHA were related statistically significantly in the short term with diurnal noise levels. Relative risks (RRs) for total admissions due to mental disorders and self-inflicted injuries, in the case of diurnal noise was RR: 1.008 95%CI (1.003 1.013). Admissions attributable to diurnal noise account for 5.5% of total admissions across the study period. There was no association between hospital admissions and chemical air pollution.

CONCLUSION

Noise is a variable that shows a statistically significant short-term association with EHMHA across all age groups in the MAR region. The results of this study may serve as a basis for drawing up public health guidelines and plans, which regard these variables as risk factors for mental disorders, especially in the case of noise, since this fundamentally depends on anthropogenic activities in highly urbanised areas with high levels of traffic density.

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.

Short-term effects of air pollution and noise on emergency hospital admissions in Madrid and economic assessment

INTRODUCTION

The aim of this study was to study the effect of air pollution and noise has on the population in Madrid Community (MAR) in the period 2013-2018, and its economic impact.

METHODS

Time series study analysing emergency hospital admissions in the MAR due to all causes (ICD-10: A00-R99), respiratory causes (ICD-10: J00-J99) and circulatory causes (ICD-10: I00-I99) across the period 2013-2018. The main independent variables were mean daily PM_2.5, PM₁₀, NO₂, 8-h ozone concentrations, and noise. We controlled for meteorological variables, Public Holidays, seasonality, and the trend and autoregressive nature of the series, and fitted generalised linear models with a Poisson regression link to ascertain the relative risks and attributable risks. In addition, we made an economic assessment of these hospitalisations.

RESULTS

The following associations were found: NO₂ with admissions due to natural (RR: 1.007, 95% CI: 1.004-1.011) and respiratory causes (RR: 1.012, 95% CI: 1.005-1.019); 8-h ozone with admissions due to natural (RR: 1.049, 95% CI: 1.014-1.046) and circulatory causes (RR: 1.088, 95% CI: 1.039-1.140); and diurnal noise (L_Aeq7-23h) with admissions due to natural (RR: 1.001, 95% CI: 1.001-1.002), respiratory (RR: 1.002, 95% CI: 1.001-1.003) and circulatory causes (RR: 1.003, 95% CI: 1.002-1.005). Every year, a total of 8246 (95% CI: 4580-11,905) natural-cause admissions are attributable to NO₂, with an estimated cost of close on €120 million and 5685 (95% CI: 2533-8835) attributed to L_Aeq7-23h with an estimated cost of close on €82 million.

CONCLUSIONS

Nitrogen dioxide, ozone and noise are the main pollutants to which a large number of hospitalisations in the MAR are attributed, and are thus responsible for a marked deterioration in population health and high related economic impact.

Mutations in HID1 Cause Syndromic Infantile Encephalopathy and Hypopituitarism

OBJECTIVE

Precursors of peptide hormones undergo posttranslational modifications within the trans-Golgi network (TGN). Dysfunction of proteins involved at different steps of this process cause several complex syndromes affecting the central nervous system (CNS). We aimed to clarify the genetic cause in a group of patients characterized by hypopituitarism in combination with brain atrophy, thin corpus callosum, severe developmental delay, visual impairment, and epilepsy.

METHODS

Whole exome sequencing was performed in seven individuals of six unrelated families with these features. Postmortem histopathological and HID1 expression analysis of brain tissue and pituitary gland were conducted in one patient. Functional consequences of the homozygous HID1 variant p.R433W were investigated by Seahorse XF Assay in fibroblasts of two patients.

RESULTS

Bi-allelic variants in the gene HID1 domain-containing protein 1 (HID1) were identified in all patients. Postmortem examination confirmed cerebral atrophy with enlarged lateral ventricles. Markedly reduced expression of pituitary hormones was found in pituitary gland tissue. Colocalization of HID1 protein with the TGN was not altered in fibroblasts of patients compared to controls, while the extracellular acidification rate upon stimulation with potassium chloride was significantly reduced in patient fibroblasts compared to controls.

INTERPRETATION

Our findings indicate that mutations in HID1 cause an early infantile encephalopathy with hypopituitarism as the leading presentation, and expand the list of syndromic CNS diseases caused by interference of TGN function. ANN NEUROL 2021;90:149-164.

Therapeutic enquiries about biological agents as a tool to identify safety aspects and patterns of use

Background

Biotechnological agents (BA) are increasingly being used in clinical practice. We aimed to determine, whether enquiries about them to a therapeutic consultation service have also become more frequent, and to describe the information requested in these consultations.

Methods

We retrospectively reviewed 14 104 therapeutic consultations collected in a computerised database between 2000 and 2014. Enquiries about BA (monoclonal antibodies, fusion proteins or cytokine antagonists) were chosen. Information on the type of BA, underlying condition, type of enquiry and affiliation of the enquirer was retrieved and compared with data from consultations about other agents.

Results

During the study period, 365 enquiries about 30 different BA were received. Only 4% of them were received before 2004, while 48.8% were received after 2010. Rituximab, infliximab, adalimumab and etanercept were most frequently enquired about. Agent selection (n=184) and/or adverse effects (n=174) were the most frequent reasons for making an enquiry. Most enquiries about an agent selection were made about an off-label use (n=164), mainly for systemic autoimmune diseases (n=61). Over half of the enquiries about adverse effects were about their teratogenic potential (n=96). Enquiries about BA more often requested an opinion (87.7% vs 77.7%) were made by physicians (89.9% vs 76.9%), from a hospital (81.6% vs 44.5%) and regarded a specific patient (87.4% vs 74.5%).

Conclusions

Therapeutic consultations about BA are increasing. Most of them are related to uncertainties of health professionals regarding any new medicine: their off-label use, actual adverse effects or the teratogenic potential of the involved agents.

Implementation of a virtual laboratory for training on sound insulation testing and uncertainty calculations in acoustic tests

This paper describes a methodology and case study for the implementation of educational virtual laboratories for practice training on acoustic tests according to international standards. The objectives of this activity are (a) to help the students understand and apply the procedures described in the standards and (b) to familiarize the students with the uncertainty in measurement and its estimation in acoustics. The virtual laboratory will not focus on the handling and set-up of real acoustic equipment but rather on procedures and uncertainty. The case study focuses on the application of the virtual laboratory for facade sound insulation tests according to ISO 140-5:1998 (International Organization for Standardization, Geneva, Switzerland, 1998), and the paper describes the causal and stochastic models and the constraints applied in the virtual environment under consideration. With a simple user interface, the laboratory will provide measurement data that the students will have to process to report the insulation results that must converge with the "virtual true values" in the laboratory. The main advantage of the virtual laboratory is derived from the customization of factors in which the student will be instructed or examined (for instance, background noise correction, the detection of sporadic corrupted observations, and the effect of instrument precision).

Assessment of noise exposure during commuting in the Madrid subway

Because noise-induced hearing impairment is the result not only of occupational noise exposure but also of total daily noise exposure, it is important to take the non-occupational exposure of individuals (during commuting to and from their jobs, at home, and during recreational activities) into account. Mass transit is one of the main contributors to non-occupational noise exposure. We developed a new methodology to estimate a representative commuting noise exposure. The methodology was put into practice for the Madrid subway because of all Spanish subway systems it covers the highest percentage of worker journeys (22.6%). The results of the application highlight that, for Madrid subway passengers, noise exposure level normalized to a nominal 8 hr (L(Ex,8h-cj) ) depends strongly on the type of train, the presence of squealing noise, and the public address audio system, ranging from 68.6 dBA to 72.8 dBA. These values play an important role in a more complete evaluation of a relationship between noise dose and worker health response.

Reduction in Calculated Uncertainty of a Noise Map by Improving the Traffic Model Data Through Two Phases

The influence of applying European default traffic values to the making of a noise map was evaluated in a typical environment like Palma de Mallorca. To assess these default traffic values, a first model has been created and compared with measured noise levels. Subsequently a second traffic model, improving the input data used for the first one, has been created and validated according to the deviations. Different methodologies were also examined for collecting model input data that would be of higher quality, by analysing the improvement generated in the reduction in the uncertainty of the noise map introduced by the road traffic noise emission.

Lack of linkage and association of adrenomedullin and its receptor genes in French Caucasian rheumatoid arthritis trio families

OBJECTIVE

Rheumatoid arthritis (RA) is characterized by hyperplasia of fibro-blast-like synoviocytes (FLSs), in part due to apoptosis resistance. Adrenomedullin, an anti-apoptotic peptide, is secreted more by RA than osteoarthritis FLSs. Adrenomedullin binds to a heterodimeric functional receptor, of calcitonin receptor-like receptor (CRLR) coupled with a receptor activity-modifying protein-2 (RAMP-2), which is also overexpressed by rheumatoid synoviocytes. Since adrenomedullin decreases RA FLS apoptosis, possibly contributing to the development of pannus, study of adrenomedullin and its receptor genes might reveal a linkage and association in French Caucasian RA trio families.

METHODS

Within each of 100 families, one RA-affected patient and both parents underwent genotyping for polymorphisms of adrenomedullin, CRLR and RAMP-2, by PCR-restricted fragment-length polymorphism (RFLP) or Taqman 5' allelic discrimination assay. Statistical analysis relied on the transmission disequilibrium test, the affected family-based controls and the genotype relative risk. Haplotypes of CRLR were inferred, and linkage and association studies were performed.

RESULTS

No significant transmission disequilibrium or association between the three genes and RA was observed. CRLR haplotypes revealed two major haplotypes, but no significant linkage with RA.

CONCLUSION

Our findings provided no significant linkage or association of adrenomedullin and CRLR-RAMP-2 genes with RA in the studied trio families. The two CRLR polymorphisms rs3771076 and rs3771084 should be investigated in larger samples.

[Vitamin B complex and homocysteine in chronic renal failure]

Metabolic, biochemical, and hormonal changes occur in chronic renal failure usually associated with hyponutrition states. In predialysis patients, knowing the nutritional state about water-soluble vitamins such as thiamine, riboflavin, pyridoxine, cianocobalamine, and folic acid is becoming more and more important since some of the manifestations of chronic renal failure may be due to the deficiency of some of these water-soluble vitamins. The metabolic pathways in which most of these vitamins participate are interrelated and it is difficult to understand how the individual deficits of each vitamin affect renal pathology. This work aims at reviewing not only this issue but also the status of these water-soluble vitamins that different authors have found in groups of predialysis patients. On the other hand, the issue on the high prevalence of hyperhomocysteinemia in chronic renal failure as the main mortality risk factor due to cardiovascular pathologies as well as the implication of these vitamins in the metabolism of homocysteine, and consequently in plasma levels of this metabolite in predialysis patients is reviewed.

Successful Kidney Transplantation Reduces Hyperplastic Parathyroid Gland

INTRODUCTION

In dialysis patients, the parathyroid glands (PTGs) may increase progressively, producing abnormal bone metabolism. Changes in PTG volume among patients with hyperplastic PTGs are not well known after kidney transplantation. This study investigated PTG volume by ultrasound (US).

METHODS

US of PTG was performed immediately (US-0) and 12 months after (US-12) transplantation to identify glands in all recipients. We calculated the percentage reduction in PTG volume (R%PTG). We declared it significant when it was > or =35%. Bone biochemical markers and renal function were recorded sequentially.

RESULTS

Among engrafted patients, parathyroid US-0 was performed in 47 and US-0 and US-12 in 36. Some visible gland was observed upon US-0 in 13 recipients, a group that showed higher pretransplantation parathyroid hormone (PTH) levels than the remaining 34 patients with no visible glands (627 +/- 360.0 vs 280 +/- 240.9 pg/mL; P < .05). Of 36 recipients with US-0 and US-12, the baseline study identified PTGs in 12 patients (p+ group), while the remaining 24 had no identified glands (p- group). In the p+ group, no PTG, at US-12 were visible in four patients, and a significant R%PTG was observed in three at this time, representing a reduction in gland volume after transplantation among 58.3% of p+ patients. There was a progressive reduction in PTH among both groups. Patients with glandular volume reduction displayed better renal function: serum creatinine 1.7 +/- .79 versus 2.9 +/- .74 mg/dL (P < .05).

CONCLUSIONS

Transplantation reversed hyperparathyroidism and PTG volume among recipients who achieved nearly normal renal function.

[Posttransplant regression of uremic tumoral calcinosis]

Uremic tumoral calcinosis is the massive calcium-phosphate deposits in periarticular tissues, usually around large joints. It has been described between 1-7% hemodialysis patients and although its etiopathogenesis is unknown, it is associated to severe hyperparathyroidism, elevation of the serum calcium-phosphorus product or hiperphosphataemia. We describe the case of tumoral calcinosis in the shoulder due to hiperphosphataemia and elevated calcium-phosphorus product, treated with low calcium intensive dialysis and fast relapse that disappears after renal transplantation.

Effect of Statin Treatment on Oxidative Stress and Renal Function in Renal Transplantation

The beneficial action of statins on the lipid profile, cardiovascular disease, and death is well known. Besides their lipid-lowering role, these drugs have pleiotropic action that derive from their prevention of the synthesis of isoprenoids, mediators in cell signaling. Thus, due to their antioxidant capacity, statins can decrease the production of reactive oxygen species by inhibiting NAD(P)H oxidase activity. Previous studies by our group have described increased oxidative stress status in renal transplantation that might benefit from HMG CoA reductase inhibitor therapy. The aim of this study was to assess the influence of statins on stress parameters and their relevance to renal function in kidney transplantation. In 58 transplanted patients a first blood sample was obtained, without statins followed by 21 patients treated with statins (group 1) and 37 patients without drug (group 0) for a 6-month study period. We collected clinical data as well biochemical results on lipid profile, creatinine and oxidative stress. Lipid profile reduction was significant among group 1 compared with group 0. An increased glutathione peroxidase (GPx) among observed in all patients was greater in the statin-treated group (P = .006). No differences in creatinine or Cockroft-Gault values were observed between before versus after drug administration. In conclusion, statin treatment in renal transplantation improves the lipid profile and may increase GPx-measured antioxidant capacity but appears to have no short-term effect on renal function.

Development of real-time and conventional RT-PCR assays for the detection of potato yellow vein virus (PYVV)

Potato yellow vein virus (PYVV) is considered a quarantine pathogen in the European and Mediterranean Plant Protection Organization (EPPO) area. This virus is widespread and damaging at its centre of origin in South America. Current detection methods are either time-consuming or difficult to interpret. This paper reports the development of a sensitive, high throughput, real-time reverse transcription (RT)-PCR assay, based on TaqMan chemistry, suitable for PYVV detection. In addition, a reliable conventional RT-PCR assay for PYVV detection is also presented. Although less sensitive (1000 times less sensitive in direct comparison), this method requires less sophisticated equipment and as such should be a useful alternative to the real-time technique in some testing laboratories. The two assays presented here could assist in the implementation of quarantine measures for PYVV identification and in routine indexing of PYVV for the production of virus-free seed potatoes in areas of South America where the virus is highly damaging.

Relationship between oxidative stress parameters and atherosclerotic signs in the carotid artery of stable renal transplant patients

Reactive oxygen species (ROS) may participate in atheroma plaque formation, which may be noninvasively diagnosed by Doppler ultrasound of carotid artery. We sought to determine the relationship between the presence of carotid artery lesions and oxidative parameters to identify factors that may influence these lesions in renal transplant patients. Fifty renal transplanted patients with stable renal function and without diabetes mellitus were studied for more than 1 year posttransplantation. Echo Doppler examination of the carotid artery was performed to assess the intimal media thickness (IMT), atheroma plaques, calcification, and stenosis. Data were collected on oxidative parameters: malondialdehyde (MDA), glutathione peroxidase (GPx), catalase, superoxide dismutase (SOD), glutathione reductase (GR), and lipid profile. The serum GPx level among patients without atheroma plaques, calcification, or stenosis was higher than in those with ultrasound signs. The LDL cholesterol fraction was lower in patients with no ultrasound signs of atherosclerotic lesions; total cholesterol values showed the same behavior. In conclusion, transplanted patients with atheromatous plaques, calcification, and carotid stenosis have a greater degree of hypercholesterolemia and lower antioxidant activity (lower GPx). Recipient age was the principal risk factor for the presence of increased IMT, atheroma plaque, calcification, and/or stenosis of carotid artery in renal transplant patients.

Interleukin-1 receptor antagonist is upregulated during diet-induced obesity and regulates insulin sensitivity in rodents

AIMS/HYPOTHESIS

The IL-1 receptor antagonist (IL-1Ra) is an anti-inflammatory cytokine known to antagonise the actions of IL-1. We have previously shown that IL-1Ra is markedly upregulated in the serum of obese patients, is correlated with BMI and insulin resistance, and is overexpressed in the white adipose tissue (WAT) of obese humans. The aim of this study was to examine the role of IL-1Ra in the regulation of glucose homeostasis in rodents.

METHODS

We assessed the expression of genes related to IL-1 signalling in the WAT of mice fed a high-fat diet, as well as the effect of Il1rn (the gene for IL-1Ra) deletion and treatment with IL-1Ra on glucose homeostasis in rodents.

RESULTS

We show that the expression of Il1rn and the gene encoding the inhibitory type II IL-1 receptor was upregulated in diet-induced obesity. The blood insulin:glucose ratio was significantly lower in Il1rn ( -/- )animals, which is compatible with an increased sensitivity to insulin, reinforced by the fact that the insulin content and pancreatic islet morphology of Il1rn ( -/- ) animals were normal. In contrast, the administration of IL-1Ra to normal rats for 5 days led to a decrease in the whole-body glucose disposal due to a selective decrease in muscle-specific glucose uptake.

CONCLUSIONS/INTERPRETATION

The expression of genes encoding inhibitors of IL-1 signalling is upregulated in the WAT of mice with diet-induced obesity, and IL-1Ra reduces insulin sensitivity in rats through a muscle-specific decrease in glucose uptake. These results suggest that the markedly increased levels of IL-1Ra in human obesity might contribute to the development of insulin resistance.

The lack of beta-adrenoceptors results in enhanced insulin sensitivity in mice exhibiting increased adiposity and glucose intolerance

We and others have previously shown that triple knockout mice lacking the beta1/beta2/beta3-adrenoceptors (beta-less mice) developed a progressive obesity at adulthood. Here, we studied the glucose homeostasis in beta-less mice before the onset of obesity. We show that beta-less mice have increased fat mass and are glucose intolerant. In addition, we observed that beta-less mice have impaired glucose-induced insulin secretion and exhibit an increase in liver PEPCK gene expression in the fed state, suggesting that they have increased gluconeogenesis. Although these characteristics are usually associated with insulin resistance, beta-less mice exhibit enhanced insulin sensitivity during insulin tolerance tests. This is keeping with the results obtained during euglycemic-hyperinsulinemic clamps showing that beta-less mice display increased insulin responsiveness with normal suppression of hepatic glucose production. Altogether, our results suggest that an intact beta-adrenergic system is required to regulate overall glucose homeostasis and, in particular, insulin-mediated glucose uptake, most likely at the level of muscles and adipose tissue.

Modulation Factors of Oxidative Status in Stable Renal Transplantation

Reactive oxygen species (ROS) trigger a biomolecular alteration that causes functional and structural changes. In renal transplantation, there is an increase in oxidative phenomena related to endothelial dysfunction, inflammation, and atherosclerosis, the main cause of cardiovascular complications and chronic allograft failure. The present study was designed to assess the oxidative state of transplant patients with stable renal function, in order to establish differences in oxidative, biochemical, and clinical parameters between patients treated with tacrolimus versus cyclosporine. We studied 67 stable kidney transplant patients treated with calcineurin inhibitors who were not receiving cholesterol-lowering therapy, and 14 healthy subjects. Data were collected on biochemical parameters: lipid profile (apoA, apoB, total cholesterol and fractions, and triglycerides); urea; and creatinine; oxidative parameters: malondialdehyde (MDA) as a lipid peroxidation marker, glutathione peroxidase (GPx), catalase, superoxide dismutase (SOD), glutathione reductase (GR), and antibodies against oxidized LDL; and clinical variables. Transplanted patients showed a higher oxidative status (MDA increase and GPx decrease) than healthy subjects. The oxidative status did not differ between the cyclosporine and tacrolimus cohorts. Some factors during the posttransplant period, such as delayed graft function, cytomegalovirus infection, and microalbuminuria, which may damage renal function, produce a decreased antioxidant capacity (lower GPx).

Hypothyroidism in rats decreases peripheral glucose utilisation, a defect partially corrected by central leptin infusion

AIMS/HYPOTHESIS

The aims of this work were to determine the effect of hypothyroidism on insulin-stimulated glucose turnover and to unravel the potential mechanisms involved in such an effect.

METHODS

Hypothyroidism was induced by administration of propylthiouracil, with partial T4 substitution. Euglycaemic-hyperinsulinaemic clamps, associated with the labelled 2-deoxy-D-glucose technique for measuring tissue-specific glucose utilisation, were used. To assess a possible involvement of leptin in the modulation of glucose metabolism by hypothyroidism, leptin was infused intracerebroventricularly for 6 days. A group of leptin-infused rats was treated with rT3 to determine a potential role of T3 in mediating the leptin effects.

RESULTS

Compared with euthyroid rats, hypothyroid animals exhibited decreased overall glucose turnover and decreased glucose utilisation indices in skeletal muscle and adipose tissue. Leptinaemia in hypothyroid rats was lower while resistin mRNA expression in adipose tissue was higher than in euthyroid animals. Intracerebroventricular leptin infusion in hypothyroid rats partially restored overall, muscle and adipose tissue insulin-stimulated glucose utilisation and improved the reduced glycaemic response observed during insulin tolerance tests. The leptin effects were due neither to the observed increase in plasma T3 levels nor to changes in the high adipose tissue resistin expression of hypothyroid rats. The administration of leptin to hypothyroid animals was accompanied by increased expression of muscle and adipose tissue carnitine palmitoyl transferases, decreased plasma NEFA levels and reduced muscle triglyceride content.

CONCLUSIONS/INTERPRETATION

Hypothyroidism is characterised by decreased insulin responsiveness, partly mediated by an exaggerated glucose-fatty acid cycle that is partly alleviated by intracerebroventricular leptin administration.

Role of glucocorticoids in the physiopathology of excessive fat deposition and insulin resistance

Glucocorticoids are important hormones in the regulation of metabolic homeostasis. We infused normal rats with dexamethasone given intracerebroventricularly (i.c.v.) for 3 days. This resulted in hyperphagia, hyperinsulinemia, and marked insulin resistance. Similar metabolic defects were observed following i.c.v. infusion of neuropeptide Y (NPY) in normal rats. As central dexamethasone infusion enhanced NPY content in the arcuate nucleus, it suggested that its metabolic effects are mediated by NPY. Moreover, due to the lack of effects observed in vagotomized animals, activation of the parasympathetic nervous system by central dexamethasone infusion is proposed. Glucocorticoid action is known to involve prereceptor metabolism by enzymes such as 11beta-HSD-1 that converts inactive into active glucocorticoids. Mice overexpressing 11beta-HSD-1 in adipose tissue were shown to be obese and insulin resistant. We recently observed that adipose tissue 11beta-HSD-1 mRNA expression is increased at the onset of high-fat diet-induced obesity and positively correlated with the degree of hyperglycemia. In human obesity, increased adipose tissue 11beta-HSD-1 expression and activity were also reported. Resistin is a new adipose tissue-secreted hormone shown to play a role in glucose homeostasis by increasing hepatic glucose production and inhibiting muscle and adipose tissue glucose utilization. We observed increased adipose tissue resistin expression in the early phase of high-fat diet-induced obesity as well as decreased resistin expression in response to leptin. A positive correlation between glycemia and adipose tissue resistin expression further suggested a role of this hormone in the development of insulin resistance. The melanocortin system is another important player in the regulation of energy balance. Peripheral administration of a melanocortin agonist decreased food intake and body weight and favored lipid oxidation, effects that were more marked in obese than in lean rats. It is proposed that both resistin and melanocortin agonists may influence adipose tissue 11beta-HSD-1, thereby decreasing or enhancing glucose metabolism.

Changes in glycemia by leptin administration or high- fat feeding in rodent models of obesity/type 2 diabetes suggest a link between resistin expression and control of glucose homeostasis

Resistin is an adipose-derived hormone that has been proposed as a link among obesity, insulin resistance, and diabetes. In agreement with a role of resistin in insulin resistance, the administration of recombinant resistin led to glucose intolerance in mice and impaired insulin action in rat liver. However, the regulation of resistin expression by physiological conditions, hormones, or agents known to modulate insulin sensitivity does not always support the association between resistin and obesity-induced insulin resistance. In the present study we investigated the effects of leptin administration on adipose resistin expression in insulin-resistant and obese ob/ob mice. We show that the expression of resistin mRNA and protein in adipose tissue is lower in ob/ob than in wild-type control mice, in agreement with the reduced adipocyte resistin mRNA level reported in several models of obesity. Leptin administration in ob/ob mice resulted in improvement of insulin sensitivity concomitant with a decrease in resistin gene expression. The lack of effect of leptin on resistin in db/db mice indicated that the leptin inhibitory action on resistin expression requires the long leptin receptor isoform. In addition, we demonstrated that the effect of leptin on resistin expression was centrally mediated. High-fat feeding in C57BL/6J wild-type mice, which is known to induce the development of obesity and insulin resistance, produced an increase in resistin expression. Interestingly, in both ob/ob and high fat-fed mice we obtained a striking positive correlation between glycemia and resistin gene expression. In conclusion, our results demonstrate that leptin decreases resistin expression and suggest that resistin may influence glucose homeostasis.

Up-regulation of fatty acid metabolizing-enzymes mRNA in rat spinal cord during persistent peripheral local inflammation

Persistent peripheral inflammation is associated with repetitive painful inputs into the spinal cord, leading to a chronic pain state. Related dramatic changes occur in the central nervous system (CNS) including central sensitization, which results in hyperalgesia. This neural plasticity involves in part fatty acids as functional and structural compounds. We hypothesized that central modification of fatty acids metabolism might occur after prolonged peripheral noxious stimulation. In the present study, the regulation of genes involved in fatty acids metabolism in the rat CNS was investigated during a chronic pain state. Using semiquantitative RT-PCR, we explored in the neuraxis the mRNA expression of brain acyl-CoA synthetases (ACS) and acyl-CoA oxidase (ACO), which are major fatty acid-metabolizing enzymes, following complete Freund's adjuvant (CFA) injection into a hind paw. Similar spinal up-regulation of the isoforms ACS2, ACS3, ACS4, and of ACO was detected early after 30 min, reaching a maximal after 6 h post-injection. Other peaks were also observed after 4 and 21 days post-inoculation, corresponding to the acute and chronic inflammation, respectively. Induction occurred only in the lumbar spinal cord ipsilaterally to the inflamed paw and was completely inhibited by a local anaesthesia of the sciatic nerve, suggesting a neural transmission of the inducing signal. Moreover, intrathecal injection of MK801, a noncompetitive NMDA antagonist, partially prevented these inductions, highlighting the involvement of the neurotransmitter glutamate in the central ACS and ACO up-regulation. These findings suggest that the fatty metabolism is stimulated in the CNS during a chronic pain state.

[Malnutrition and mortality in hemodialyzed patients]

BACKGROUND

Due to the ageing of the general population and improved techniques, the acceptance rate of patients starting dialysis has increased. Mortality remains high and the factors involved include nutritional parameters, which also seem to be of value for prognosis in this population.

SCOPE OF THE STUDY

We proposed a prospective study in our haemodialysis population in order to establish the factors with the greatest predictive value for mortality.

PATIENTS AND METHODS

One hundred stabilized patients receiving this technique were included in the study, with registration of any concomitant pathologies, their severity and the presence of HBP; we carried out a clinical assessment measuring nutritional parameters and functional capacity, with anthropometric and analytical measurements with dialysis dosage and protein catabolism rate. The observation period lasted for one year. The statistical analysis compared survivors and dead patients by means of a bivariant analysis, and after selecting the significant variables, log regression was applied.

RESULTS

The annual death rate was 15%. The bivariant analysis highlights the greater age and the prevalence of vascular pathology prior to dialysis, with a greater severity score and prior weight loss, as well as a lessened functional capacity and clinical assessment score among the dead patients. The analytical parameters showed lymphocytes to be significantly lower among the deceased. The log regression analysis revealed the predictive value of severity, followed by initial vascular co-morbidity, lymphocyte levels less than 1,200 and the nutritional clinical assessment score.

CONCLUSIONS

1. Severity was the main factor predicting mortality. 2. The presence of vascular co-morbidity at the start of dialysis increased the likelihood of death by more than ten times. 3. Lymphopenia of less than 1,200 and low scores in the subjective overall assessment were predictors of mortality.

[The role of PET-FDG in questionable diagnosis of relapse in the presence of radionecrosis of brain tumors]

INTRODUCTION

Although CT and MR are sensitive techniques for the detection of cerebral tumours, both have limitations in distinguishing between tumour relapse (TR) and post-treatment radionecrosis (RN).

PATIENTS AND METHODS

In this study we have determined the usefulness of metabolic imaging with PET-FDG in such situations. We assessed 70 patients with CNS tumours (22 low grade astrocytomas, 25 high grade astrocytomas, 3 oligodendrogliomas, 13 metastatic tumours and 7 other tumours. All had been treated with radiotherapy and other treatments such as radiosurgery, chemotherapy or different types of surgery, and presented clinical pictures which made it necessary to decide the differential diagnosis of relapse or radionecrosis.

RESULTS

In the PET-FDG study visual and semiquantitative analysis was done by SUV (Standardized Update Value). Confirmation of the findings was obtained in 44 cases (24 TR and 20 RN). MR was doubtful or inconclusive in most cases, whilst with PET correct diagnosis was made in all cases.

CONCLUSIONS

Metabolic imaging with PET-FGD is better than anatomostructural imaging techniques for differential diagnosis between tumour relapse and radionecrosis in CNS tumours which have been treated. Prospective studies are necessary for evaluation of SUV as a factor for prognosis of survival.

Urinary albumin excretion in Spanish children. Niño Jesus Group

We measured urinary albumin excretion in 2,224 school-children (1,168 boys, 1,056 girls) aged 2-18 years, between 1989 and 1990 to establish reference values. We recorded all pathological antecedents and findings from physical examination, including anthropometric parameters and arterial blood pressure. The analytical study included serum total protein, albumin and creatinine. The second-morning urine and the nightly (rest) 10-h urine sample were collected and we determined the concentration of albumin and creatinine. We found a positive statistically significant correlation between the urinary albumin excretion (micrograms/10 h) and age, height, weight and body surface area. We suggest that it would be useful to relate the urinary albumin excretion to body surface area. The mean value for albumin excretion was 3.49 micrograms/ml in boys and 3.63 micrograms/ml in girls. The urinary albumin/creatinine ratio showed a high correlation with the albumin excretion (r = 0.958).