Source and symptoms of COVID-19 among hospital workers in Milan

Background

Healthcare workers (HCWs) are commonly infected by SARS-CoV-2 and represent one of the most vulnerable groups. Adequate prevention strategies are necessary to guarantee HCWs’ safety, as well as to prevent dissemination of the infection among patients.

Aims

To describe a case series of SARS-CoV-2-positive HCWs in a large public healthcare organization in Milan (Italy) during the most devastating weeks of the epidemic and analyse the sources, symptoms and duration of SARS-CoV-2 infection.

Methods

This study included 172 SARS-CoV-2-positive HCWs who were infected between the 25th of February and the 7th of April 2020. A nasopharyngeal swab (NPS) and RT-PCR were used to indicate.

Results

Initially, the most common sources of infection were other positive HCWs (49%). Medical doctors and nursing assistants were most frequently infected, with infection rates of 53/1000 and 50/1000, respectively. COVID-19 departments were less affected than internal medicine, surgery, intensive care, or emergency room. The most commonly reported symptom was mild cough, while loss of smell (anosmia) and loss of taste (ageusia) were reported as moderate and severe by 30–40% of HCWs. The time necessary for 50% of workers to recover from the infection was 23 days, while it took 41 days for 95% of HCWs to become virus-free.

Conclusions

HCWs are commonly infected due to close contacts with other positive HCWs, and non-COVID departments were most affected. Most HCWs were asymptomatic or subclinical but contact tracing and testing of asymptomatic HCWs help identify and isolate infected workers.

Insulin clearance as the major player in the hyperinsulinaemia of black African men without diabetes

AIM

To investigate relationships between insulin clearance, insulin secretion, hepatic fat accumulation and insulin sensitivity in black African (BA) and white European (WE) men.

METHODS

Twenty-three BA and twenty-three WE men with normal glucose tolerance, matched for age and body mass index, underwent a hyperglycaemic clamp to measure insulin secretion and clearance, hyperinsulinaemic-euglycaemic clamp with stable glucose isotope infusion to measure whole-body and hepatic-specific insulin sensitivity, and magnetic resonance imaging to quantify intrahepatic lipid (IHL).

RESULTS

BA men had higher glucose-stimulated peripheral insulin levels (48.1 [35.5, 65.2] × 10³ vs. 29.9 [23.3, 38.4] × 10³ pmol L^-1  × min, P = .017) and lower endogeneous insulin clearance (771.6 [227.8] vs. 1381 [534.3] mL m^-2 body surface area min ^-1 , P < .001) compared with WE men. There were no ethnic differences in beta-cell insulin secretion or beta-cell responsivity to glucose, even after adjustment for prevailing insulin sensitivity. In WE men, endogenous insulin clearance was correlated with whole-body insulin sensitivity (r = 0.691, P = .001) and inversely correlated with IHL (r = -0.674, P = .001). These associations were not found in BA men.

CONCLUSIONS

While normally glucose-tolerant BA men have similar insulin secretory responses to their WE counterparts, they have markedly lower insulin clearance, which does not appear to be explained by either insulin resistance or hepatic fat accumulation. Low insulin clearance may be the primary mechanism of hyperinsulinaemia in populations of African origin.

Ethnic differences in intrahepatic lipid and its association with hepatic insulin sensitivity and insulin clearance between men of black and white ethnicity with early type 2 diabetes

Intrahepatic lipid (IHL) is linked with reduced hepatic insulin sensitivity and insulin clearance. Despite their high risk for type 2 diabetes (T2D), there have been limited investigations of these relationships in black populations. We investigated these relationships in 18 white European (WE) and 18 black West African (BWA) men with T2D <5 years. They underwent magnetic resonance imaging to quantify IHL, a hyperinsulinemic euglycaemic clamp with [6,6 ² H₂ ] glucose infusion to assess hepatic insulin sensitivity and a hyperglycaemic clamp to assess insulin clearance. BWA men had lower IHL than WE men (3.7 [5.3] vs 6.6 [10.6]%, P = 0.03). IHL was inversely associated with basal hepatic insulin sensitivity in WE but not BWA men (BWA: r = -0.01, P = 0.96; WE: r = -0.72, P = 0.006) with a significant interaction by ethnicity (P_interaction  = 0.05); however, IHL was not associated with % suppression of endogenous glucose production by insulin in either ethnicity. IHL showed a trend to an association with insulin clearance in BWA only (BWA: r = -0.42, P = 0.09; WE: r = -0.14, P = 0.58). The lack of association between IHL and hepatic insulin sensitivity in BWA men indicates IHL may play a lesser detrimental role in T2D in BWA men.

Associations Between Pancreatic Lipids and β-Cell Function in Black African and White European Men With Type 2 Diabetes

CONTEXT

Intrapancreatic lipid (IPL) has been linked to β-cell dysfunction. Black populations disproportionately develop type 2 diabetes (T2D) and show distinctions in β-cell function compared with white populations.

OBJECTIVE

We quantified IPL in white European (WE) and black West African (BWA) men with early T2D and investigated the relationships between IPL and β-cell insulin secretory function (ISF).

DESIGN, SETTING, AND PARTICIPANTS

We performed a cross-sectional assessment of 18 WE and 19 BWA middle-age men with early T2D as part of the South London Diabetes and Ethnicity Phenotyping study.

MAIN OUTCOME MEASURES

The participants underwent Dixon MRI to determine IPL in the pancreatic head, body, and tail and subcutaneous and visceral adipose tissue volumes. Modeled first- and second-phase ISFs were comprehensively determined using C-peptide measurements during a 3-hour meal tolerance test and a 2-hour hyperglycemic clamp test.

RESULTS

The WE men had greater mean IPL levels compared with BWA men (P = 0.029), mainly owing to greater IPL levels in the pancreatic head (P = 0.009). The mean IPL level was inversely associated with orally stimulated first-phase ISF in WE but not BWA men (WE, r = -0.554, P = 0.026; BWA, r = -0.183, P = 0.468). No association was found with orally stimulated second-phase ISF in either WE or BWA men. No associations were found between the mean IPL level and intravenously stimulated ISF.

CONCLUSIONS

The IPL levels were lower in BWA than WE men with early T2D, and the lack of inverse association with first-phase ISF in BWA men indicates that IPL might be a less important determinant of the development of T2D in BWA than in WE men.

Circulating innate immune markers and outcomes in treatment-naïve advanced non-small cell lung cancer patients

INTRODUCTION

Innate immunity represents the first step of activation of the immune system and dictates the quality of adaptive immune responses. Studies have reported links between systemic inflammatory or innate immune markers and prognosis in patients with lung cancer. To our knowledge, the prospective and concomitant study of these systemic markers has never been performed.

METHODS

Advanced treatment-naive non-small cell lung cancer (NSCLC) patients eligible for first-line platinum-based chemotherapy were prospectively included from December 2012 to July 2015 (N = 148). Blood samples of patients were collected before the first cycle for fresh NK cell phenotyping. Peripheral blood mononuclear cells were cryopreserved for natural cytotoxicity receptor (NCR) genotyping as well as sera for NCR's ligand quantification. Data on leukocytes, neutrophils and monocyte counts and lactate dehydrogenase (LDH) levels were extracted from electronic medical records.

RESULTS

Among all studied markers, monocytosis, neutrophilia, leucocytosis, high LDH and sBAG6 levels and reduced levels of NCR3 transcripts were associated with poor overall survival (OS) in univariate analysis. The levels of NCR3 transcripts was linked to age, number of metastatic sites, monocyte counts, LDH and sBAG6 levels. Neutrophilia was associated to high sBAG6 levels. NCR3 was the unique innate immune parameter that remained as an independent factor associated with both OS (P = 0.003) and progression-free survival (P = 0.009) in the multivariate analysis.

CONCLUSION

This study brought evidence that these biomarkers are entangled; parameters associated with an inflammatory process were related to reduced levels of NCR3 transcripts. Finally, the level of NCR3 transcripts was independently associated with outcomes in treatment-naive patients with advanced NSCLC.

Ethnic differences in insulin secretory function between black African and white European men with early type 2 diabetes

AIM

To test the hypothesis that men of black (West) African ethnicity (black African men [BAM]) with early type 2 diabetes (T2D) would have greater insulin secretory deficits compared with white European men (WEM), following prediabetic hypersecretion.

METHODS

In 19 BAM and 15 WEM, matched for age, body mass index and duration of diabetes, we assessed and modelled insulin secretory responses to hyperglycaemia stimulated intravenously (hyperglycaemic clamp) and orally (meal tolerance test).

RESULTS

With similar post-challenge glucose responses, BAM had lower second-phase C-peptide responses to intravenous glucose (BAM 70.6 vs WEM 115.1 nmol/L/min [ratio of geometric mean 0.55, 95% confidence interval {CI} 0.37, 0.83]; P = .006) and to oral glucose (BAM 65.4 vs WEM 88.5 nmol/L/min [mean difference -23.2, 95% CI -40.0, -6.3]; P = .009). Peripheral insulin response in BAM to oral glucose was preserved (BAM 47.4 vs WEM 59.4 nmol/L/min [ratio of geometric mean 0.89, 95% CI 0.59, 1.35]; P = .566), with relative reductions in insulin clearance (BAM 506.2 vs WEM 630.1 mL/m² BSA/min [mean difference -123.9, 95% CI -270.5, 22.6]; P = .095), associated with enhanced incretin responses (gastric inhibitory polypeptide incremental area under the curve: BAM 46.8 vs WEM 33.9 μg/L/min [mean difference 12.9, 95% CI 2.1, 23.7]; P = .021).

CONCLUSIONS

In early T2D, BAM had significantly lower insulin secretory responses to intravenous and oral stimulation than WEM. Lower insulin clearance, potentially driven by increased incretin responses, may act to preserve peripheral insulin concentrations. Tailoring early management strategies to reflect distinct ethnic-specific pathophysiology may improve outcomes in this high-risk population.

Association of free-living physical activity measures with metabolic phenotypes in type 2 diabetes at the time of diagnosis. The Verona Newly Diagnosed Type 2 Diabetes Study (VNDS)

BACKGROUND AND AIM

Lifestyle is considered a major determinant of risk of type 2 diabetes (T2D). We investigated whether daily physical activity (DPA) is associated with beta-cell function (BF) and/or insulin sensitivity (IS) in patients with T2D at the time of diagnosis.

METHODS AND RESULTS

In 41 subjects enrolled in the Verona Newly-Diagnosed Type 2 Diabetes Study we assessed: (1) IS, by euglycaemic insulin clamp; (2) BF, estimated by prolonged-OGTT minimal modeling and expressed as derivative and proportional control; (3) DPA and energy expenditure (EE), assessed over 48-h monitoring by a validated wearable armband system. Study participants (median [IQR]; age: 62 [53-67] years, BMI: 30.8 [26.5-34.3] Kg m^-2, HbA1c: 6.7 [6.3-7.3]%; 49.7 [45.4-56.3] mmol/mol) were moderately active (footsteps/day: 7773 [5748-10,927]; DPA_≥3MET: 70 [38-125] min/day), but none of them exercised above 6 metabolic equivalents (MET). EE, expressed as EE_TOT (total daily-EE) and EE_≥3MET (EE due to DPA_≥3MET) were 2398 [2226-2801] and 364 [238-617] Kcal/day, respectively. IS (M-clamp 630 [371-878] μmol/min/m²) was positively associated with DPA and EE, independent of age, sex and BMI (p < 0.05). Among the DPA and EE parameters assessed, DPA_≥3MET and EE_TOT were independent predictors of IS in multivariable regression analyses, adjusted for age, sex, BMI (R² = 16%, R² = 19%, respectively; p < 0.01). None of model-derived components of BF was significantly associated with DPA or accompanying EE.

CONCLUSIONS

Our study highlighted moderate levels of DPA and total EE as potential determinants of IS, but not BF, in T2D at the time of diagnosis. Intervention studies are needed to conclusively elucidate the effect of DPA on these features.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov.

UNIQUE IDENTIFIER

NCT01526720.

Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab

Background

Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity.

Patients and methods

Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel.

Results

A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A.

Conclusion

Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.

Towards a classification strategy for complex nanostructures

The range of possible nanostructures is so large and continuously growing, that collating and unifying the knowledge connected to them, including their biological activity, is a major challenge. Here we discuss a concept that is based on the connection of microscopic features of the nanomaterials to their biological impacts. We also consider what would be necessary to identify the features that control their biological interactions, and make them resemble each other in a biological context.

Detecting the shape of anisotropic gold nanoparticles in dispersion with single particle extinction and scattering

The shape and size of nanoparticles are important parameters affecting their biodistribution, bioactivity, and toxicity. The high-throughput characterisation of the nanoparticle shape in dispersion is a fundamental prerequisite for realistic in vitro and in vivo evaluation, however, with routinely available bench-top optical characterisation techniques, it remains a challenging task. Herein, we demonstrate the efficacy of a single particle extinction and scattering (SPES) technique for the in situ detection of the shape of nanoparticles in dispersion, applied to a small library of anisotropic gold particles, with a potential development for in-line detection. The use of SPES paves the way to the routine quantitative analysis of nanoparticles dispersed in biologically relevant fluids, which is of importance for the nanosafety assessment and any in vitro and in vivo administration of nanomaterials.

A Novel Insulin/Glucose Model after a Mixed-Meal Test in Patients with Type 1 Diabetes on Insulin Pump Therapy

Current closed-loop insulin delivery methods stem from sophisticated models of the glucose-insulin (G/I) system, mostly based on complex studies employing glucose tracer technology. We tested the performance of a new minimal model (GLUKINSLOOP 2.0) of the G/I system to characterize the glucose and insulin dynamics during multiple mixed meal tests (MMT) of different sizes in patients with type 1 diabetes (T1D) on insulin pump therapy (continuous subcutaneous insulin infusion, CSII). The GLUKINSLOOP 2.0 identified the G/I system, provided a close fit of the G/I time-courses and showed acceptable reproducibility of the G/I system parameters in repeated studies of identical and double-sized MMTs. This model can provide a fairly good and reproducible description of the G/I system in T1D patients on CSII, and it may be applied to create a bank of “virtual” patients. Our results might be relevant at improving the architecture of upcoming closed-loop CSII systems.

Interleukin-6 as a potential positive modulator of human beta-cell function: an exploratory analysis-the Verona Newly Diagnosed Type 2 Diabetes Study (VNDS) 6

AIMS

Recent studies in mouse models of T2D showed that interleukin-6 (IL-6), released from skeletal muscle, is associated with increased glucose-dependent insulin secretion. Few data currently exist exploring the relationship between IL-6 and beta-cell function in humans. We investigated whether IL-6 is positively associated with beta-cell function in newly diagnosed T2D. We extended the same analyses to IL-10, because it regulated similarly to IL-6 in skeletal muscle, and TNF-α and C-reactive protein (CRP), as general biomarkers of inflammation.

METHODS

In 330 VNDS participants, we assessed (1) basal plasma concentrations of IL-6, IL-10, TNF-α, and CRP; (2) beta-cell function, estimated by OGTT minimal modeling and expressed as derivative (DC) and proportional control (PC); (3) insulin sensitivity, by euglycemic insulin clamp.

RESULTS

IL-6 was positively associated with PC in both univariate analysis (p = 0.04) and after adjustment for age, sex, BMI, HbA1c, and M-clamp (p = 0.01). HbA1c was the major independent contributor to the overall variance of PC (16 %), followed by BMI and IL-6 (~2 % each). Similar results were obtained for IL-10 (p = 0.048, univariate; p = 0.04, fully adjusted). TNF-α and CRP were not significantly associated with any component of beta-cell function.

CONCLUSIONS

Our data are the first evidence in human subjects that an endocrine loop involving IL-6 may act as positive modulator of glucose-dependent insulin secretion. Further functional studies are needed to corroborate IL-6 system as a potential druggable target in diabetes.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01526720 ( http://www.clinicaltrial.gov ).

Is common genetic variation at IRS1, ENPP1 and TRIB3 loci associated with cardiometabolic phenotypes in type 2 diabetes? An exploratory analysis of the Verona Newly Diagnosed Type 2 Diabetes Study (VNDS) 5

BACKGROUND AND AIMS

Insulin resistance is a hallmark of type 2 diabetes (T2DM), it is often accompanied by defective beta-cell function (BF) and is involved in the pathophysiology of cardiovascular disease (CVD). Commonalities among these traits may recognize a genetic background, possibly involving the genetic variation of insulin signaling pathway genes. We conducted an exploratory analysis by testing whether common genetic variability at IRS1, ENPP1 and TRIB3 loci is associated with cardiovascular risk traits and metabolic phenotypes in T2DM.

METHODS AND RESULTS

In 597 drug-naïve, GADA-negative, newly-diagnosed T2DM patients we performed: 1) genotyping of 10 independent single-nucleotide polymorphisms covering ∼ 90% of common variability at IRS1, ENPP1 and TRIB3 loci; 2) carotid artery ultrasound; 3) standard ECG (n = 450); 4) euglycaemic insulin clamp to assess insulin sensitivity; 5) 75 g-OGTT to estimate BF (derivative and proportional control) by mathematical modeling. False discovery rate of multiple comparisons was set at 0.20. After adjustment for age, sex and smoking status, rs4675095-T (IRS1) and rs4897549-A (ENPP1) were significantly associated with carotid atherosclerosis severity, whilst rs7265169-A (TRIB3) was associated with ECG abnormalities. Rs858340-G (ENPP1) was significantly associated with decreased insulin sensitivity, independently of age, sex and body-mass-index. No consistent relationships were found with BF.

CONCLUSION

Some associations were found between intermediate phenotypes of CVD and common genetic variation of gatekeepers along the insulin signaling pathway. These results need be replicated to support the concept that in T2DM the CVD genetic risk clock may start ticking long before hyperglycemia appears. ClinicalTrials.gov Identifier: NCT01526720.

Type 2 diabetes mellitus: a disease of the governance of the glucose-insulin system: an experimental metabolic control analysis study

BACKGROUND AND AIMS

The relatives role of each component of the glucose-insulin system in determining hyperglycemia in type 2 diabetes is still under debate. Metabolic Control Analysis (MCA) quantifies the control exerted by each component of a system on a variable of interest, by computing the relevant coefficients of control (CCs), which are systemic properties. We applied MCA to the intravenous glucose tolerance test (IVGTT) to quantify the CCs of the main components of the glucose-insulin system on intravenous glucose tolerance.

METHODS AND RESULTS

We combined in vivo phenotyping (IVGTT/euglycaemic insulin clamp) and in silico modeling (GLUKINSLOOP.1) to compute the CCs of intravenous glucose tolerance in healthy insulin-sensitive (n = 9, NGR-IS), healthy insulin-resistant (n = 7, NGR-IR) and subdiabetic hyperglycemic (n = 8, PreT2DM) individuals and in patients with newly diagnosed type 2 diabetes (n = 7, T2DM). Altered insulin secretion and action were documented in NGR-IR and PreT2DM groups, but only 1st phase insulin secretion was significantly lower in T2DM than in PreT2DM (p < 0.05). The CCs changed little in the nondiabetic groups. However, several CCs were significantly altered in the patients (e.g. CCs of beta cell: -0.75 ± 0.10, -0.64 ± 0.15, -0.56 ± 0.09 and -0.19 ± 0.04 in NGR-IS, NGR-IR, PreT2DM and T2DM, respectively; p < 0.01 by MANOVA), and they could not be corrected by matching in silico nondiabetic and T2DM groups for 1st phase secretion.

CONCLUSIONS

Type 2 diabetes is characterized not only by loss of function of the elements of the glucose-insulin system, but also by changes in systemic properties (CCs). As such, it could be considered a disease of the governance of the glucose-insulin system.

Variants and haplotypes of TCF7L2 are associated with β-cell function in patients with newly diagnosed type 2 diabetes: the Verona Newly Diagnosed Type 2 Diabetes Study (VNDS) 1

CONTEXT

Intronic variants of TCF7L2 are confirmed genetic risk factors for type 2 diabetes and are associated to alterations in beta cell function in nondiabetic individuals.

OBJECTIVE

The objective of the study was to test whether TCF7L2 variability may affect β-cell function also in patients with type 2 diabetes.

DESIGN

This was a cross-sectional association study.

SETTING

The study was conducted at a university hospital referral center for diabetes.

PATIENTS

Patients included 464 (315 males and 149 females) glutamic acid decarboxylase-negative patients [age: median 59 yr (interquartile range: 52-65); body mass index: 29.3 kg/m(2) (26.5-32.9); fasting plasma glucose: 7.0 mmol/liter (6.1-8.0)] with newly diagnosed type 2 diabetes.

INTERVENTION(S)

Interventions included frequently sampled oral glucose tolerance test and euglycemic insulin clamp.

MAIN OUTCOME MEASURE(S)

β-Cell function (derivative control and proportional control); insulin sensitivity; genotypes of the following TCF7L2 single-nucleotide polymorphisms: rs7901695, rs7903146, rs11196205, and rs12255372.

RESULTS

Both rs7901695 and rs7903146 diabetes risk alleles were associated with reduced proportional control of β-cell function (P = 0.019 and P = 0.022, respectively). Two low-frequency haplotypes were associated with extreme (best and worst) phenotypes of β-cell function (P < 0.01). No associations between TCF7L2 genotypes and insulin sensitivity were detected.

CONCLUSIONS

TCF7L2 diabetes risk variants, either as single-nucleotide polymorphisms or as haplotypes, detrimentally influence β-cell function and might play a role in determining the metabolic phenotype of patients with newly diagnosed type 2 diabetes.

Prediabetes in obese youth: a syndrome of impaired glucose tolerance, severe insulin resistance, and altered myocellular and abdominal fat partitioning

BACKGROUND

Impaired glucose tolerance is common among obese adolescents, but the changes in insulin sensitivity and secretion that lead to this prediabetic state are unknown. We investigated whether altered partitioning of myocellular and abdominal fat relates to abnormalities in glucose homoeostasis in obese adolescents with prediabetes.

METHODS

We studied 14 obese children with impaired glucose tolerance and 14 with normal glucose tolerance, of similar ages, sex distribution, and degree of obesity. Insulin sensitivity and secretion were assessed by the euglycaemic-hyperinsulinaemic clamp and the hyperglycaemic clamp. Intramyocellular lipid was assessed by proton nuclear magnetic resonance spectroscopy and abdominal fat distribution by magnetic resonance imaging.

FINDINGS

Peripheral glucose disposal was significantly lower in individuals with impaired than in those with normal glucose tolerance (mean 35.4 [SE 4.0] vs 60.6 [7.2] micromoles per kg lean body mass per min; p=0.023) owing to a reduction in non-oxidative glucose disposal metabolism (storage). Individuals with impaired glucose tolerance had higher intramyocellular lipid content (3.04 [0.43] vs 1.99 [0.19]%, p=0.03), lower abdominal subcutaneous fat (460 [47] vs 626 [39] cm2, p=0.04), and slightly higher visceral fat than the controls (70 [11] vs 47 [6] cm2, p=0.065), resulting in a higher ratio of visceral to subcutaneous fat (0.15 [0.02] vs 0.07 [0.01], p=0.002). Intramyocellular and visceral lipid contents were inversely related to the glucose disposal and non-oxidative glucose metabolism and positively related to the 2 h plasma glucose concentration.

INTERPRETATION

In obese children and adolescents with prediabetes, intramyocellular and intra-abdominal lipid accumulation is closely linked to the development of severe peripheral insulin resistance.

Prevalence of nosocomial infections in Italy: result from the Lombardy survey in 2000

A one-day survey was carried out in 88 out of 113 public hospitals in Lombardy to obtain prevalence rates of hospital-acquired infections (HAIs) by hospital departments and to identify the pathogens more frequently involved. In total 18667 patients were surveyed, representing 72% of the average daily total of occupied beds in public hospitals in Lombardy. The overall prevalence of HAI was 4.9%. The highest prevalence was observed in intensive care units and in spinal units. The prevalence of bloodstream infections was 0.6%; pneumonia 1.1%; urinary tract infections 1.6% and gastrointestinal infections 0.4%. In surgical patients the prevalence of surgical site infections was 2.7%. The most frequently isolated pathogen from all sites of infections was Escherichia coli (16.8%), followed by Staphylococcus aureus (15.0%), Pseudomonas aeruginosa (13.2%) and Candida spp. (8.7%). Methicillin-resistant S. aureus accounted for 23% of all isolated S. aureus. The results provide baseline data for rational priorities in allocation of resources, for further studies and for infection control activities.

Altered blood pressure variability in patients with congestive heart failure

OBJECTIVE

Congestive heart failure (CHF) is characterized by sympathetic overactivity but reduced variability of heart interval and sympathetic nerve activity; little information exists, however, about the alterations in blood pressure variability in this syndrome, especially during excitatory manoeuvres such as tilting or exercise.

DESIGN AND METHODS

Nine patients with CHF (age 62+/-1 years, NYHA class II-III, ejection fraction 33+/-1%, peak VO2 14.1+/-3.2 ml/min per kg body weight [mean +/- SEM]) and eight healthy control subjects (age 58+/-1 years) with normal left ventricular function were studied. Blood pressure (Finapres), R-R interval (ECG) and respiration (nasal thermistor) were recorded during 15-min periods of supine rest, 70 degree head-up tilting, submaximal bicycling exercise and post-exercise recovery. Total variance and the power of the spectral components of blood pressure (HF, respiratory-related; LF, 0.03-0.14 Hz; and VLF, 0.02-0.003 Hz) were measured.

RESULTS

Compared with control subjects, CHF patients have, first, a normal overall blood pressure variability during supine rest but a failure to increase this variability in response to head-up tilt and exercise; second, a suppressed LF spectral component of blood pressure at rest and in response to head-up tilt and exercise; and third, reappearance of LF blood pressure power during postexercise recovery.

CONCLUSIONS

In CHF patients, overall blood pressure variability and its LF spectral component are altered at rest and during sympathoexcitatory manoeuvres. Somewhat paradoxically, however, the depressed LF blood pressure power is partially restored during a 15-min recovery period, indicating that at least part of the CHF-related alterations of blood pressure variability have the potential to revert back towards normal under appropriate physiological circumstances.

[Anesthesia in early surgery and endovascular therapy for aneurysmic subarachnoid hemorrhage]

Early surgery after SAH is frequently performed. The most important problems for anesthesiologists are the risk of rebleeding, the alteration of autoregulation and CO2 responsiveness, cardiac, respiratory and electrolytic alterations. In this phase the brain may be ischemic-edematous or haemorrhagic-compressive and the choice of anesthetic agent is made on the basis of cerebral conditions. The main goal is to control ICP and maintain adequate CPP. The endovascular treatment with Guglielmi detachable coils is usually performed in patients with poor neurologic and/or medical conditions. General anaesthesia under aggressive monitoring is advisable to control systemic pressure and to avoid movements.

Prevention and treatment of vasospasm

Cerebral vasospasm is a frequent and severe complication of SAH. Angiographic vasospasm may be seen in 70% of patients and delayed cerebral ischemic deficits are observed in 30% of patients. Since vasodilator drugs cannot reverse cerebral vasospasm, treatment is directed to prevent vasospasm and to prevent or reverse ischemic deficits. The mainstay of treatment of vasospasm is the hypertensive hypervolemia dilution (triple H therapy); the mainstay of prevention is the calcium channel blocker nimodipine. The efficacy of triple H therapy has not been demonstrated in randomized clinical trials, while several randomized trials have demonstrated that nimodipine reduces poor outcome due to vasospasm in all grades of patients. Some randomized, clinical trials are recently performed on the efficacy of rTPA (on the basis of the correlation between the amount of cisternal blood and the incidence and severity of vasospasm) and of tirilazed (on the basis of the role of lipidic peroxidation and free radical generation in the pathogenesis of spasm). Balloon angioplasty and/or super-selective intra-arterial infusion of papaverine can be considered when patient is refractory to medical and pharmacological treatment.

Contribution of the neuro-intensivist in the choice of treatment of patients with aneurysm

During the last years embolization with Guglielmi detachable coils has provided a new alternative of treatment of intracranial aneurysms. Neuroanesthesiologists and neurointensivists have an important role in the selection of the patients to traditional surgical treatment or endovascular treatment. This selection must be a team decision on the basis of the patient's conditions. The main contribution of neuroanesthesiologists is to evaluate the patient's medical and neurologic conditions and to prospect the anesthesiological problems in each technique, especially when the patient is treated in acute phase after SAH.

Propofol anaesthesia in spontaneously breathing paediatric patients during magnetic resonance imaging

BACKGROUND

The aim of this study was to evaluate the use of propofol to induce and maintain anaesthesia in spontaneously breathing paediatric patients (age 2 weeks-11 years) during Magnetic Resonance Imaging (MRI) of the CNS.

METHODS

All patients were spontaneously breathing, without intubation, and received supplemental O2. Pulse rate, blood pressure (BP), electrocardiogram and EtCO2 were recorded in all patients, and in 38 subjects SpO2 was also monitored. Patients were divided in 2 groups according to their body weights: Group A (n = 34, bwt < or = 10 kg), and Group B (n = 48, bwt > 10 kg).

RESULTS

Dosage of propofol during the time of induction (from insertion of the i.v. cannula to positioning on the MRI table) was significantly higher in smaller children (Group A; 5.4 +/- 2.2 (SD) mg/kg) as compared to children with bwt above 10 kg (Group B; 3.7 +/- 1.6 mg/kg). Propofol dosage for maintenance of anaesthesia was significantly higher in smaller children (Group A: 10.1 +/- 5.7 vs Group B: 7.1 +/- 3.0 mgkg-1 h-1, P = 0.003). During the time of induction, transient episodes of reduced BP (< or = 20%) occurred in 6 patients in Group A and 2 patients in Group B. During anaesthesia in Group B there was 1 episode of oxygen desaturation (95%), and 3 episodes of short and mild increases of EtCO2(< or = 52 mmHg). No other side effects occurred in any patient. MRI studies were successfully completed, only 3 sequences (Group A) had to be restarted.

CONCLUSION

Propofol can be safely used for total intravenous anaesthesia in children undergoing MRI.

Peri-operative prophylaxis with phenytoin: dosage and therapeutic plasma levels

Early postoperative epilepsy is a frequent complication of supratentorial intracranial surgery. The lack of consensus on prophylaxis of early postoperative seizures with phenytoin (PHT) may be due to the different dosages used in several studies, owing to inadequate therapeutic plasma level. The aim of this study was to evaluate which dosage of PHT can maintain the therapeutic range in the early postoperative period. Twenty patients operated on for supratentorial neoplasms were randomly allocated to receive, during the last hour of the surgical procedure, loading doses of either 10 mg/kg (group A, n = 10) or 15 mg/kg (group B, n = 10) of PHT. PHT infusion rate never exceeded 30 mg/min. Six hours after the loading dose, PHT maintenance treatment (250 mg, i.v., every 8 hours) was started in all patients. PHT plasma levels were evaluated from the end of the intra-operative loading infusion up to 24 h. During the first six hours after the loading dose, phenytoin plasma levels fell below the therapeutic range (10-20 mg/l) in 7 out of the 10 patients receiving 10 mg/kg, while in the patients treated with 15 mg/kg, PHT plasma levels were always in the therapeutic range (P < or = 0.0001). PHT maintenance dose was sufficient to keep plasma levels within the therapeutic range in 8 patients in group A, and in all the patients in group B. It is concluded that a loading dose of 15 mg/kg, followed by postoperative treatment, is necessary to guarantee therapeutic plasma levels of phenytoin in the immediate postoperative period, when seizure risk is very high.

EGF stimulates lamellipod extension in metastatic mammary adenocarcinoma cells by an actin-dependent mechanism

Changes in lamellipod extension and chemotaxis in response to EGF were analysed for MTLn3 cells (a metastatic cell line derived from the 13762NF rat mammary adenocarcinoma). Addition of EGF produced a cessation of ruffling followed by extension of hyaline lamellipods containing increased amounts of F-actin at the growing edge. A non-metastatic cell line (MTC) derived from the same tumor did not show such responses. Lamellipod extension was maximal within 5 min, followed by retraction and resumption of ruffling. Maximal area increases due to lamellipod extension occurred at about 5 nM EGF. Chemotactic and chemokinetic responses, measured using a microchemotaxis chamber, were also greatest at 5 nM. Cytochalasin D inhibited EGF-stimulated responses including lamellipod extension, increases in F-actin in lamellipods, and chemotaxis. Nocodazole affected chemotaxis at higher concentrations but not EGF-induced lamellipod extension. We conclude that polymerization of F-actin at the leading edges of lamellipods is necessary for extension of lamellipods and chemotaxis of MTLn3 cells in response to EGF. The motility and chemotaxis responses of this metastatic cell line have strong similarities to those seen in well-characterized chemotactic cells such as Dictyostelium and neutrophils.

Cardiac and carotid structure in arterial hypertension and in hypertrophic cardiomyopathy

The aim of this study was to measure intima-media thickness (IMT) of the common carotid artery (CCA) in patients with hypertrophic cardiomyopathy (HCM) and in hypertensive patients with left ventricular hypertrophy (LVH). We studied 73 subjects: 20 normotensive healthy subjects as control group (I); 20 patients with essential hypertension without LVH (II); 20 hypertensives with LVH (III), and 13 normotensive patients with HCM (IV). Each subject underwent a complete echocardiographic and vascular ultrasonographic study in order to assess left ventricular parameters and the IMT at the level of the CCA. Left ventricular mass index (LVMI) was significantly higher in groups III and IV than in groups I and II (156 +/- 18 and 157 +/- 31 vs. 94 +/- 14 and 98 +/- 10 g/m2, respectively, p < 0.01), while IMT was significantly greater in group III but not in the others [0.88 +/- 0.04 vs. 0.61 +/- 0.03 (I), 0.64 +/- 0.03 (II) and 0.61 +/- 0.04 (IV) mm, p < 0.01]. The correlation between LVMI and IMT was statistically significant within all the hypertensive patients (r = 0.48, p < 0.01) but not in the HCM group (r = 0.17, p = NS). The hypertensive patients with LVH showed structural alterations (related to hemodynamic and humoral factors) both at cardiac and vascular level while in patients with HCM the cardiac alterations (due to a genetic disorder) were not associated with changes at the level of the large arteries.

Nicotinamide methylation in patients with cirrhosis

Methylation reactions play an important role in the transformation of endogenous and exogenous substances. Up to 85% of all transmethylation reactions occur in the liver. Several studies have shown that these metabolic processes are greatly influenced by the presence of hepatic diseases. We investigated the methylation of nicotinamide in 16 control subjects and in 29 patients with cirrhosis (19 Child A, 10 Child B). The basal serum value of N-methyl-nicotinamide was measured in all subjects. In seven controls and in nine patients with cirrhosis (5 Child A and 4 Child B), the serum levels and urinary excretion (5 and 24 h) of N-methyl-nicotinamide were also evaluated after oral administration of nicotinamide (1.5 mg/kg body weight). The basal serum levels of N-methyl-nicotinamide were significantly (p < 0.05) higher in patients with cirrhosis (Child A: median 34 ng/ml, 16th percentile 24, 84th percentile 61; Child B median 45, 16th percentile 34, 84th percentile 81) than in controls (median 22, 16th percentile 13, 85th percentile 28). After the nicotinamide load the urinary excretion and the time course of serum N-methyl-nicotinamide in cirrhosis were also higher (p < 0.05) than in controls (24 h urinary excretion = 66.2 mg +/- 5 S.D. in cirrhosis; 47.2 +/- 10.3 in controls) (area under the serum concentration versus time curve = 68 micrograms.ml-1.min-1 +/- 22 S.D. in cirrhosis; 32 +/- 15 in controls). In conclusion, our results show that cirrhosis does not impair the efficiency of nicotinamide methylation.

[Cardiac and vascular hypertrophy in juvenile borderline hypertension: echocardiographic and ultrasonographic study]

BACKGROUND

High resolution ultrasonography is a noninvasive technique that allows us to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries, with accuracy and reproducibility.

METHODS

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensive (age 24 +/- 4 years) and in 20 normotensive subjects (age 24 +/- 4 years), as a control group. Both carotid axes were scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high resolution steerable linear array of 5 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider.

RESULTS

In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mmHg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2). The intima-media thickness of both the CCA and BIF was significantly higher in borderlines than in normotensives (CCA 0.6 +/- 0.08 vs 0.4 +/- 0.05 mm, p < 0.001; BIF 0.7 +/- 0.08 vs 0.5 +/- 0.08, p < 0.001). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.

CONCLUSIONS

Our data show that ultrasonography provides direct evidence that in young borderline hypertensives the increased left ventricular mass is associated with vascular hypertrophy.

Ultrasonographic evaluation of cardiac and vascular changes in young borderline hypertensives

We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 20 borderline hypertensives (age 24 +/- 4 years) and in 20 normotensive subjects (age 23 +/- 6 years), as a control group. Both carotid axes have been scanned from different views on a transversal and longitudinal section. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In borderline patients blood pressure (147.8 +/- 10.5/90.7 +/- 6.6 mm Hg) and left ventricular mass index (102.5 +/- 15.3 g/m2) were significantly higher than in normotensive subjects (blood pressure 120.5 +/- 11.5/78.0 +/- 5.4 mm Hg; left ventricular mass 90.5 +/- 14.3 g/m2, p < 0.01 and p < 0.05 respectively). The intima-media thickness of both the CCA and BIF was significantly higher in borderline hypertensives than in normotensives (CCA 0.6 +/- 0.08 vs. 0.4 +/- 0.05 mm, p < 0.01; BIF 0.7 +/- 0.08 vs. 0.5 +/- 0.08, p < 0.01). In the whole population there was a statistically significant correlation between the carotid wall thickness and the left ventricular mass.(ABSTRACT TRUNCATED AT 250 WORDS)

[Risk of postoperative epilepsy in acute surgery of cerebral aneurysms]

Forty-nine patients operated during an early clipping phase of cerebral aneurysm were reviewed; none had an associated ventricular flooding and/or intraparenchymal hematoma. Starting from the day of operation 37 patients were treated with anticonvulsant drugs using methods and dosages where were unlikely to guarantee efficacious cover. Forty-two patients made a satisfactory recovery, 5 patients died and 2 had severe neurological sequelae; 2 patients (4.4%) had early seizures during the first week after operation. In view of the inadequate cover of the anticonvulsant drugs and the homogeneous clinical characteristics of patients included in the study, the low number of attacks suggests an overall re-evaluation of anticonvulsant treatment and the need to select patients with a higher risk of an epileptic attack.

[Early epilepsy in surgery of extra-axial supratentorial neoplasms]

A retrospective study was performed to evaluate the incidence of seizure and anticonvulsant prophylaxis in 138 patients operated from september 1987 to august 1989 for extra-axial supratentorial tumors. 15 patients (10.9%) developed seizures in the early post-operative period. We have considered the importance of histological type and side of lesions, a previous history of epilepsy and the pre and intraoperative prophylaxis. We can say that there is a statistical significance between sellar and middle cranial fossa tumors and the frequency of post-operative epilepsy and that anticonvulsant prophylaxis can reduce post-operative seizure. There is no statistical significance between the previous history of epilepsy the type of anesthesia and post-operative seizure.

[Ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension]

High resolution ultrasonography allows the accurate and reproducible measurement of thickness and lumen diameter of carotid arteries. We investigated Common carotid (CCA) and bifurcation intima-media thickness in 40 hypertensive patients, 20 without left ventricular hypertrophy (LVH) (age 42 +/- 10 years) and 20 with LVH (age 44 +/- 12 years), all free from other important cardiovascular risk factors. Both carotid axes were scanned from different views (anterior, lateral, posterior) on traversal and longitudinal section, using a high resolution steerable (HRS) 5.0 MHz linear array. Carotid diameter and thickness from longitudinal section were measured. CCA parameters were taken 20 mm caudally to flow divider. Using the B-mode as a guide we assessed LVH presence with M-mode technique when left ventricular mass index (LVMI) > or = 135 g/m2 for men and > or = 110 g/m2 for women. In hypertensive patients with LVH, left ventricular mass was significantly higher than in those without LVH (156 +/- 38 vs 98 +/- 10 g/m2, p < 0.01). Even blood pressure was significantly higher in hypertrophic group (172 +/- 21/108 +/- 9 vs 158 +/- 11/99 +/- 12 mmHg, p < 0.01), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness scanned in both CCA and bifurcation resulted significantly higher in hypertensives with LVH (CCA: 0.85 +/- 0.02 mm vs 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 mm vs 0.70 +/- 0.03 mm, p < 0.01). We also noticed a statistically significant correlation between carotid wall thickness and left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)

[Continuous monitoring of O2 saturation in cerebral blood. A guide for the nursing of brain trauma patients in coma]

Manual ventilation is frequently performed by nurses to control increases in intracranial pressure (ICP) or during physiotherapy in head injured comatose patients. The effects of manual ventilation (n = 251) on ICP, cerebral perfusion pressure (CPP) and EEG have been studied in 18 mechanically ventilated patients. A fall in ICP was easily obtained but a fall in arterial blood pressure was often present at the same time. Thus a reduction in CPP resulted in 36% of occasions. Prophylactic boluses of thiopental (n = 67) before noxious stimuli obtained a fall in ICP in 99% of occasions but resulted in a decrease in CPP in 46%. The fall in ICP, due to the decrease in cerebral blood flow (CBF) by hypocapnia or metabolic depression and/or arterial hypotension, may be beneficial in hyperaemic brains but may precipitate cerebral hypoxia in ischaemic lesions. Relevant information about cortical metabolism (CMR) may be obtained from EEG monitoring by Cerebral Function Monitor but, unfortunately, no data about CBF are clinically available. The Authors suggest that the continuous monitoring of jugular bulb oxygen saturation (SjO2) may offer a clinically useful index of CBF adequacy to CMR. Findings from a preliminary study in 5 patients demonstrate that a severe decrease in SjO2 has been frequently caused by manual ventilation, hypothetically related to severe cerebral ischemia. High levels of SjO2 have been induced by endotracheal suction and physiotherapy, probably related to severe hyperemia. As prevention of ischaemic and hyperaemic insults is a major goal of treatment, the A. suggest that these undesirable effects of nursing might be avoided if nurses could take advantage of continuous monitoring of SjO2.

Prevalence of physiological valvular regurgitation in hypertensive patients: echocardiographic and color Doppler study

Since the advent of the Doppler color flow echocardiography, the presence of a small degree of insufficiency of the cardiac valves has been detected with relative frequency in structurally and functionally normal hearts. Data about this so-called 'physiological' regurgitation are presently available only in normotensive subjects and athletes. We therefore studied the prevalence of this phenomenon in a group of patients with essential hypertension compared to a population of normotensive subjects. To this purpose, a Doppler color flow echocardiographic study was performed in 130 essential hypertensive patients (72M/58F; age 44.2 +/- 13.5 years; BP 154.3 +/- 12.8/98.3 +/- 7.1 mm Hg) without any evidence of left ventricular hypertrophy or cardiopathy and in 100 normal subjects (59M/41F; age 41.2 +/- 14.8 years; BP 119.1 +/- 8.1/79.2 +/- 8.1 mm Hg). We conclude that in patients with essential hypertension the physiological regurgitant jets are present in one or more cardiac valves; moreover, the regurgitation of the mitral and aortic valve is found with more frequency than in the normotensive control group (36.1 vs. 27.0% and 17.7 vs. 11.0%, respectively). These data suggest that the increased afterload of the left ventricle may play an important role in the pathogenesis of even minor degree of insufficiency of the cardiac valves. As this finding does not appear to have a pathological relevance, the main clinical implication of this study is that it is not advisable to create a jatrogenic heart disease in the hypertensive patients routinely screened by the echo-Doppler technique.

Echocardiographic and ultrasonographic evaluation of cardiac and vascular hypertrophy in patients with essential hypertension

High-resolution ultrasonography is a noninvasive technique that allows to investigate the cardiovascular system, in particular the wall thickness and the lumen diameter of the arteries with accuracy and reproducibility. We measured the intima-media thickness of the common carotid artery (CCA) and of its bifurcation (BIF) in 40 patients with essential hypertension, 20 of them with left ventricular hypertrophy (LVH; age 42 +/- 10 years) and 20 without LVH (age 44 +/- 12 years); no other major cardiovascular risk factor was present in all the patients. Both carotid axes have been scanned from different views (anterior, lateral, posterior) on a transversal and longitudinal section using a high-resolution steerable linear array of 5.0 MHz. Carotid diameter and thickness were measured in the longitudinal section. CCA parameters were assessed 20 mm caudally to the flow divider. In patients with LVH, blood pressure (172 +/- 21/108 +/- 9 mm Hg) and left ventricular mass index (156 +/- 38 g/m2) were significantly (p < 0.01) higher than in patients without LVH (blood pressure: 158 +/- 11/99 +/- 12 mm Hg; left ventricular mass index: 98 +/- 10 g/m2), while there was no difference in serum glycemia, triglycerides, total and fractioned cholesterol levels. The intima-media thickness of both the CCA and BIF was significantly higher in the hypertensives with LVH (CCA: 0.85 +/- 0.02 vs. 0.65 +/- 0.02 mm; BIF: 0.93 +/- 0.04 vs. 0.70 +/- 0.03 mm, p < 0.01). There was a statistically significant correlation between the carotid wall thickness and the left ventricular mass index.(ABSTRACT TRUNCATED AT 250 WORDS)