Spin-lattice relaxation time in water/graphene-oxide dispersion

We present the results of the calculations of the spin-lattice relaxation time of water in contact with graphene oxide by means of all-atom molecular dynamics simulations. We fully characterized the water-graphene oxide interaction through the calculation of the relaxation properties of bulk water and of the contact angle as a function of graphene oxide oxidation state and comparing them with the available experimental data. We then extended the calculation to investigate how graphene oxide alters the dynamical and relaxation properties of water in different conditions and concentrations. We show that, despite the diamagnetic nature of the graphene oxide, the confining effects of the bilayers strongly affect the longitudinal relaxation properties of interfacial water, which presents a reduced dynamics due to hydrogen bonds with oxygen groups on graphene oxide. This property makes graphene oxide an interesting platform to investigate water dynamics in confined geometries and an alternative contrast-agent for magnetic resonance imaging applications, especially in view of the possibility to functionalize graphene oxide from theranostic perspectives.

Tracking COVID-19 in the United States With Surveillance of Aggregate Cases and Deaths

Early during the COVID-19 pandemic, the Centers for Disease Control and Prevention (CDC) leveraged an existing surveillance system infrastructure to monitor COVID-19 cases and deaths in the United States. Given the time needed to report individual-level (also called line-level) COVID-19 case and death data containing detailed information from individual case reports, CDC designed and implemented a new aggregate case surveillance system to inform emergency response decisions more efficiently, with timelier indicators of emerging areas of concern. We describe the processes implemented by CDC to operationalize this novel, multifaceted aggregate surveillance system for collecting COVID-19 case and death data to track the spread and impact of the SARS-CoV-2 virus at national, state, and county levels. We also review the processes established to acquire, process, and validate the aggregate number of cases and deaths due to COVID-19 in the United States at the county and jurisdiction levels during the pandemic. These processes include time-saving tools and strategies implemented to collect and validate authoritative COVID-19 case and death data from jurisdictions, such as web scraping to automate data collection and algorithms to identify and correct data anomalies. This topical review highlights the need to prepare for future emergencies, such as novel disease outbreaks, by having an event-agnostic aggregate surveillance system infrastructure in place to supplement line-level case reporting for near-real-time situational awareness and timely data.

Hepatocellular liver injury in hospitalized patients affected by COVID-19: Presence of different risk factors at different time points

BACKGROUND

Prevalence and clinical impact of increased liver function tests in patients affected by Coronavirus disease 2019 (COVID-19) is controversial.

AIMS

This observational study evaluates the prevalence of transaminases elevation in hospitalized patients affected by COVID-19 and investigates the presence of factors associated with hepatocellular injury and with mortality.

METHODS

Data of 292 adult patients with confirmed COVID-19 admitted to the Ente Ospedaliero Cantonale (Switzerland) were retrospectively analyzed.

RESULTS

Transaminases were increased in about one-third of patients on hospital admission and two-thirds of patients during the hospital stay. On hospital admission, transaminases were more commonly elevated in younger patients, who also reported elevated C reactive protein and a higher degree of respiratory failure. Independent factors associated with abnormal transaminases during hospitalization were drugs, in particular paracetamol (OR=2.67; 95% CI=1.38-5.18; p = 0.004) and remdesivir (OR=5.16; 95% CI=1.10-24.26; p = 0.04). Mortality was independently associated to age (OR = 1.09; 95% CI=1.05-1.13; p<0.001), admission to intensive care unit (OR=5.22; 95% CI=2.28-11.90; p<0.001) and alkaline phosphatase peak (OR=1.01; 95% CI=1.00- 1.01; p = 0.01).

CONCLUSIONS

On hospital admission, factors associated with liver damage were linked to demographic and clinical characteristics (age, inflammation and hypoxia) while, during hospitalization, drug treatment was related to development and progression of hepatocellular damage. Mortality was associated with alkaline phosphate peak value.

Relevance of chronic hepatitis E in liver transplant recipients: a real-life setting

The chronic course of hepatitis E virus (HEV) infections in orthotopic liver transplant (OLT) recipients has been described previously, but prospectively collected data are rare. We aimed to study the role of chronic hepatitis E in OLT in a real-life setting. Therefore, 287 adult OLT recipients (169 male [59%], median age 56 years) were prospectively tested by HEV polymerase chain reaction assay (lower level of detection = 10 IU/mL), irrespective of their level of liver enzymes. In 4 patients (1.4%), chronic HEV infection was diagnosed. All 4 patients were male, and their age (median 48.5 years), the time since transplantation (median 45.5 months), and bilirubin level (median 0.6 mg/dL) did not differ significantly from the total cohort. However, alanine transaminase and aspartame transaminase levels were significantly higher in HEV-infected patients (75-646 U/L, median 216 U/L and 68-317 U/L, median 108 U/L) than in non-infected patients (6-617 U/L, median 41 and 6-355 U/L, median 36; P = 0.004 and 0.040, Mann-Whitney test). In 3 patients, liver biopsy was performed and revealed signs of inflammation and chronic liver disease, as enlarged densely infiltrated portal tracts with mild-to-moderate interface hepatitis. All infected patients were treated with ribavirin with the starting dose adjusted to renal function (400-800 mg/day). In 2 patients, dose reduction was necessary. Transaminases normalized in all 4 patients, and all patients cleared their infection within 3 months of ribavirin treatment. However, 1 patient experienced viral relapse 12 weeks after discontinuation. Ribavirin medication was re-started and viral clearance occurred within 8 weeks and persisted. Sequence analysis of the HEV genome of this patient revealed that he was infected with an HEV variant, which recently has been shown to have a reduced response to ribavirin in cell culture. The risk of chronic HEV infections in OLT recipients in low-endemic countries should not be overestimated. No case of chronic hepatitis E was observed in patients with normal liver enzymes, indicating that general screening of all OLT recipients is not necessary. However, if chronic hepatitis E develops, it can be treated efficiently with ribavirin.

Antagonism of histamine H4 receptors exacerbates clinical and pathological signs of experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE

The histamine H4 receptor has a primary role in inflammatory functions, making it an attractive target for the treatment of asthma and refractory inflammation. These observations suggested a facilitating action on autoimmune diseases. Here we have assessed the role of H4 receptors in experimental autoimmune encephalomyelitis (EAE) a model of multiple sclerosis (MS).

EXPERIMENTAL APPROACH

We induced EAE with myelin oligodendrocyte glycoprotein (MOG35-55 ) in C57BL/6 female mice as a model of MS. The histamine H4 receptor antagonist 5-chloro-2-[(4-methylpiperazin-1-yl)carbonyl]-1H-indole (JNJ7777120) was injected i.p. daily starting at day 10 post-immunization (D10 p.i.). Disease severity was monitored by clinical and histopathological evaluation of inflammatory cells infiltrating into the spinal cord, anti-MOG35-55 antibody production, assay of T-cell proliferation by [(3) H]-thymidine incorporation, mononucleate cell phenotype by flow cytometry, cytokine production by elisa assay and transcription factor quantification of mRNA expression.

KEY RESULTS

Treatment with JNJ7777120 exacerbated EAE, increased inflammation and demyelination in the spinal cord of EAE mice and increased IFN-γ expression in lymph nodes, whereas it suppressed IL-4 and IL-10, and augmented expression of the transcription factors Tbet, FOXP3 and IL-17 mRNA in lymphocytes. JNJ7777120 did not affect proliferation of anti-MOG35-55 T-cells, anti-MOG35-55 antibody production or mononucleate cell phenotype.

CONCLUSIONS AND IMPLICATIONS

H4 receptor blockade was detrimental in EAE. Given the interest in the development of H4 receptor antagonists as anti-inflammatory compounds, it is important to understand the role of H4 receptors in immune diseases to anticipate clinical benefits and also predict possible detrimental effects.

Modeling selective local interactions with memory

Recently we developed a stochastic particle system describing local interactions between cyanobacteria. We focused on the common freshwater cyanobacteria Synechocystis sp., which are coccoidal bacteria that utilize group dynamics to move toward a light source, a motion referred to as phototaxis. We were particularly interested in the local interactions between cells that were located in low to medium density areas away from the front. The simulations of our stochastic particle system in 2D replicated many experimentally observed phenomena, such as the formation of aggregations and the quasi-random motion of cells. In this paper, we seek to develop a better understanding of group dynamics produced by this model. To facilitate this study, we replace the stochastic model with a system of ordinary differential equations describing the evolution of particles in 1D. Unlike many other models, our emphasis is on particles that selectively choose one of their neighbors as the preferred direction of motion. Furthermore, we incorporate memory by allowing persistence in the motion. We conduct numerical simulations which allow us to efficiently explore the space of parameters, in order to study the stability, size, and merging of aggregations.

Assessment of baseline characteristics and risk factors among Emergency Department patients presenting with recent onset atrial fibrillation: a retrospective cohort study

BACKGROUND

The Cardioversion of Atrial Fibrillation in Emergency (CAFE) study was an observational, retrospective, multicenter study focusing on patients with recent onset atrial fibrillation (AF) seen in six different Emergency Departments (ED) of Rome, Italy.

AIM

The aim of this study was to present the baseline characteristics and risk factors of the patients enrolled to the CAFE study.

MATERIALS AND METHODS

We retrospectively reviewed 3085 eligible patients diagnosed with recent onset AF in any of the EDs between January 2008 and December 2009. Inclusion criteria required documented ICD-9 primary discharge/admission diagnosis of AF in the ED and stable hemodynamic conditions at presentation (systolic blood pressure > 90 mmHg). Exclusion criteria were permanent AF or an ongoing acute coronary syndrome.

RESULTS

Median age was 71 years (interquartile ranges, 62-78 years) and 50.8% were men. Palpitations was the most common symptom at ED presentation and was present in 73.5% of the study subjects. Hypertension was the most prevalent comorbidity, affecting 59.3% of the patients evaluated, and the presence of previous episode(s) of AF was also common (52.3%). Regarding home treatment, the drugs most prescribed were antiplatelets (31.2%) and diuretics (25.2%). A CHADS2 score of 0 was found in 814 patients (26.4%), while a CHADS2 score of 1 was reported in 1114 patients (36.1%). Finally, a CHADS2 score ≥ 2 was reported in 1157 patients (37.5%).

CONCLUSIONS

The present study represents an important snapshot of demographics, comorbidities, risk factors and anticoagulation management about patients with recent onset AF. Disparities were noted in anticoagulation management, suggesting that this is still a main problem among patients with AF.

Modeling local interactions during the motion of cyanobacteria

Synechocystis sp., a common unicellular freshwater cyanobacterium, has been used as a model organism to study phototaxis, an ability to move in the direction of a light source. This microorganism displays a number of additional characteristics such as delayed motion, surface dependence, and a quasi-random motion, where cells move in a seemingly disordered fashion instead of in the direction of the light source, a global force on the system. These unexplained motions are thought to be modulated by local interactions between cells such as intercellular communication. In this paper, we consider only local interactions of these phototactic cells in order to mathematically model this quasi-random motion. We analyze an experimental data set to illustrate the presence of quasi-random motion and then derive a stochastic dynamic particle system modeling interacting phototactic cells. The simulations of our model are consistent with experimentally observed phototactic motion.

B7-h1 and a mathematical model for cytotoxic T cell and tumor cell interaction

The surface protein B7-H1, also called PD-L1 and CD274, is found on carcinomas of the lung, ovary, colon, and melanomas but not on most normal tissues. B7-H1 has been experimentally determined to be an antiapoptotic receptor on cancer cells, where B7-H1-positive cancer cells have been shown to be immune resistant, and in vitro experiments and mouse models have shown that B7-H1-negative tumor cells are significantly more susceptible to being repressed by the immune system. We derive a new mathematical model for studying the interaction between cytotoxic T cells and tumor cells as affected by B7-H1. By integrating experimental data into the model, we isolate the parameters that control the dynamics and obtain insights on the mechanisms that control apoptosis.

Cardiac autonomic regulation after lung exposure to carbon nanotubes

The ultrafine (UF) component of airborne pollution may impair cardiovascular autonomic control, a high-risk condition for cardiovascular adverse events. Since engineered nanoparticles, such as single-walled carbon nanotubes (SWCNTs) share physicochemical properties with UF, they might have similar adverse effects. Aim of the study was to evaluate arterial baroreflex function (BRF) at baseline, 24 h after the first instillation, immediately before the second one, and 2 weeks later, in adult Wystar-Kyoto conscious rats undergoing two intratracheal instillations of SWCNT (eight rats) or phosphate buffer saline (PBS) (five rats) at 2-week interval. During each session, 30-min continuous recording of arterial pressure and pulse interval was performed by a telemetered catheter implanted in the abdominal aorta of the rats. BRF was studied by the sequence technique. SWCNTs dispersed in PBS (1 mg/ml) were administered immediately after sonication (1 microg/g body weight). A significant decrease in the number of baroreflex sequences (from 498 +/- 27.1 at baseline to 287 +/- 40.2 at the recording performed after 4 weeks; P < 0.05) was observed in SWCNT-instilled rats, whereas no significant change was detected in controls. These data suggest that SWCNTs may alter the BRF, thus affecting the autonomic cardiovascular control regulation.

Recurrent myocardial ischaemia during combination antiviral therapy in a patient with chronic hepatitis C and normal aminotransferase levels

A 63-year-old man with chronic hepatitis C and persistently normal alanine aminotransferase levels was treated with peginterferon alpha-2a (180 microg weekly) and ribavirin (800 mg daily). Hepatitis C virus-ribonucleic acid was negative at week 4. After 12 weeks of therapy, haemoglobin levels had decreased by 3.5mg/dL, and he developed a syncope episode with electrocardiographic signs of myocardial ischaemia. Antiviral treatment was stopped and the ischaemia-like electrocardiographic changes resolved completely within 2 months. Eight months later, because of the previous rapid virological response and patient motivation, he was treated again with peginterferon and ribavirin. Baseline and weekly electrocardiographic recordings were obtained during treatment. At week 4 hepatitis C virus-ribonucleic acid was negative. At week 8, when the haemoglobin levels had decreased by 3.4 mg/dL, the patient developed the same ischaemia-like changes that occurred during the previous treatment. Antiviral therapy was stopped and the electrocardiographic ischaemia-like changes disappeared after 1 month. The patient neither had a history of previous cardiovascular diseases, nor evidence of current disease at myocardial scintigraphy. However, a coronary microvessel spasm, possibly related to drug-toxicity and/or anaemia could not be excluded. This case indicates the need of strict electrocardiographic monitoring in elderly patients undergoing treatment with peginterferon and ribavirin.

Maternal and fetal hemodynamic effects induced by nitric oxide donors and plasma volume expansion in pregnancies with gestational hypertension complicated by intrauterine growth restriction with absent end-diastolic flow in the umbilical artery

OBJECTIVE

To evaluate the effect of plasma volume expansion (PVE) and nitric oxide (NO) donors, in addition to antihypertensive therapy for gestational hypertensive pregnancies complicated by intrauterine growth restriction (IUGR) with absent end-diastolic flow (AEDF) in the umbilical artery (UA).

METHODS

This was a case-control study into which 32 gestational hypertensive pregnancies with IUGR and AEDF were enrolled. Sixteen of these were treated with antihypertensive drugs, NO donors and PVE (Group A), and 16, matched for maternal age, gestational age and fetal conditions, were treated with antihypertensive drugs only (Group B). All patients underwent fetal and uteroplacental assessment and maternal echocardiography to evaluate total vascular resistance (TVR) and cardiac output before and 5-14 days after initiation of treatment.

RESULTS

After 5-14 days of treatment, the maternal TVR in Group A fell from 2170 +/- 248 to 1377 +/- 110 dynes.s.cm(-5) (P < 0.01), and that in Group B fell from 2090 +/- 260 to 1824 +/- 126 dynes.s.cm(-5) (P < 0.01), with the reduction being greater in Group A than in Group B (P < 0.01). There was a significant increase in cardiac output in Group A after 5-14 days of treatment vs. baseline (6.19 +/- 0.77 vs. 4.32 +/- 0.66, P < 0.001), and, after treatment, cardiac output was significantly greater in Group A than it was in Group B (6.19 +/- 0.77 vs. 4.70 +/- 0.44, P < 0.001). Reappearance of end-diastolic flow in the UA occurred in 14/16 patients in Group A but in no patients in Group B (87.5% vs. 0%, P < 0.05). The interval between detection of UA-AEDF and delivery was 28 +/- 16 days in Group A and 11 +/- 6 days in Group B (P < 0.05).

CONCLUSION

Administration of NO donors and PVE in gestational hypertensive pregnancies affected by IUGR and UA-AEDF appears to improve both maternal and fetal hemodynamics, inducing prolongation of gestation.

[Interaction between carbon nanotubes and cardiovascular autonomic nervous system regulation: proposal of an animal model and preliminary findings]

BACKGROUND

Altered autonomic cardiovascular regulation (ACR) may mediate the association between single-wall carbon nanotubes (SWCNT) exposure and adverse cardiovascular events.

MATERIAL AND METHODS

400 mg of SWCNT in 400 ml of phosphate buffer saline (PBS) or 400 ml of PBS were randomly given to 7 Wystar-Kyoto rats (400 g body wt) previously implanted in abdominal aorta with a telemetry transmitter for recordings of arterial pressure signals. Recordings were performed at baseline, 24 hours and two weeks after intratracheal instillation. The beat-by-beat time series of systolic arterial pressure (SAP) and PR interval were analyzed to identify sequences of three or more consecutive beats in which SAP and PR changed in the same (baroreflex sequences) or in the opposite direction (nonbaroreflex sequences). The mean individual slope of the sequences was calculated and taken as a measure of the baroreflex (BRS) and nonbaroreflex sensitivity for that period.

RESULTS

The 24 hour BRS response showed a 100% increase (from 4.6 to 9.2 msec/mmHg) in controls, whereas it was blunted in cases (from 5.1 to 6.1 msec/mmHg) (p < 0.05).

CONCLUSIONS

Our study demonstrates that this rat model is suitable to study the ACR during exposure to SWCNT and suggests a blunted BRS response after SWCNT instillation.

Shift work increases the frequency of duodenal ulcer in H pylori infected workers

AIM

To evaluate whether shift work is associated with an increased rate of peptic ulcer in H pylori infected workers.

METHODS

During a two year period, consecutive dyspeptic workers underwent non-invasive evaluation of H pylori status by means of urea 13C breath test or stool testing. Those testing positive were included in the study and divided into two main categories: day-time workers and shift workers. An upper gastrointestinal endoscopy was performed in all workers, and biopsy specimens were taken from the stomach to confirm the presence of H pylori infection (culture and histology).

RESULTS

A total of 247 day-time workers and 101 shift workers were included. The prevalence of duodenal ulcer was significantly higher in shift workers than in day-time workers (29 of 101 v 23 of 247; OR = 3.92, 95% CI 2.13 to 7.21), and persisted after multivariate analysis, taking into account possible confounding factors (OR = 3.96, 95% CI 2.10 to 7.47).

CONCLUSION

Shift work increases the ulcerogenic potential of H pylori infection and should be considered a risk factor for duodenal ulcer in infected shift workers. Treatment of infection in this high risk group may improve the health of workers and may reduce the economic impact of peptic ulcer.

Helicobacter pylori eradication and l-dopa absorption in patients with PD and motor fluctuations

OBJECTIVE

To investigate if Helicobacter pylori (HP) eradication could make an effective and long-lasting improvement in the pharmacokinetic and clinical response to l-dopa in patients with Parkinson disease (PD) and motor fluctuations.

METHODS

In a group of 34 HP-infected, motor-fluctuating patients with PD, the short-term (1-week) and long-term (3-month) beneficial effect of HP eradication (n = 17) was investigated in a double-blind fashion in comparison with a generic antioxidant treatment (n = 17), by means of pharmacokinetic, clinical, and gastrointestinal assessments. Results were compared with placebo treatment.

RESULTS

Differently from the antioxidant-treated patients, the HP-eradicated patients showed a significant increase of l-dopa absorption, which was coupled with a significant improvement of clinical disability and with a prolonged "on-time" duration, whereas gastritis/duodenitis scores significantly decreased in line with a better l-dopa pharmacokinetics.

CONCLUSIONS

These data demonstrate a reversible Helicobacter pylori (HP)-induced interference with l-dopa clinical response related to the impaired drug absorption, probably due to active gastroduodenitis. Therefore, the authors suggest that HP eradication may improve the clinical status of infected patients with Parkinson disease and motor fluctuations by modifying l-dopa pharmacokinetics.

Maternal total vascular resistance and concentric geometry: a key to identify uncomplicated gestational hypertension

OBJECTIVE

To evaluate the prognostic impact of elevated total vascular resistance (TVR) on the outcome of pregnancy in early mild gestational hypertension (EMGH).

DESIGN

Prospective observational study.

SETTING

Data collected from women with EMGH referred to the obstetrics outpatient clinic of Tor Vergata University from June 2003 to June 2005.

POPULATION

A total of 268 women with EMGH (systolic and diastolic blood pressure [BP] 140-150 mmHg and 90-99 mmHg, respectively, without significant proteinuria).

METHODS

Women had a maternal echocardiographic examination and BP examination within 24 hours of diagnosis. From this, the TVR was calculated and the geometric pattern of the left ventricle assessed.

MAIN OUTCOME MEASURES

Fetal/maternal adverse outcomes (pre-eclampsia, preterm delivery, placental abruption, other maternal medical problems, fetal distress, neonatal low birthweight, admittance to neonatal intensive care unit and perinatal death).

RESULTS

Ninety-two out of the 268 pregnancies showed adverse outcomes (34.3%). The best independent predictor for the composite of maternal and fetal complications was TVR (OR 64.4, 95% CI 25.9-160.1). The cutoff value was 1340 dyn seconds/cm(5) with a sensitivity and a specificity of 90 and 91%, respectively. Concentric geometry of the left ventricle was also an independent predictor (OR 4.72, 95% CI 1.85-12.04).

CONCLUSIONS

Echocardiography could help in identifying women with EMGH who subsequently develop maternal and fetal complications, allowing a classification in high-risk (TVR > 1340 dyn seconds/cm(5), concentric geometry of the left ventricle) and low-risk women (TVR < 1340 dyn seconds/cm(5), nonconcentric geometry of the left ventricle) for adverse outcomes of pregnancy.

CagA-positive Helicobacter pylori strains may influence the natural history of atherosclerotic stroke

OBJECTIVE

To test the hypothesis that infection with virulent cytotoxin-associated gene-A (CagA)-bearing Helicobacter pylori strains influences the atherosclerotic process and the clinical course in atherosclerotic stroke patients.

METHODS

ELISA was used to assess the seroprevalence of infection by H. pylori and CagA-positive strains in 185 patients. Intima-media thickness (IMT) was determined by Doppler ultrasound. Baseline, 1-week, and 1-month NIH Stroke Scale (NIHSS) scores were used to evaluate the short-term clinical course.

RESULTS

H. pylori infection was found in 79% of patients; 58% of these tested positive for CagA. IMT was higher among CagA-positive patients than among CagA-negative ones (1.13 +/- 0.26 mm vs 0.97 +/- 0.15 mm; univariate analysis, p = 0.0001; multivariate analysis, odds ratio [OR], 2.36; 95% CI, 1.57 to 3.54; p = 0.0001) or H. pylori-negative ones (1.01 +/- 0.17 mm; univariate analysis, p = 0.007; multivariate analysis, OR, 1.90; 95% CI, 1.22 to 2.97; p = 0.005). CagA-positive patients had poorer initial outcomes based on serial measurements of the NIHSS score (repeated measures analysis of variance, p < 0.0001). No significant difference in IMT and NIHSS score was found between H. pylori-positive and H. pylori-negative patients.

CONCLUSIONS

Infection with cytotoxin-associated gene-A-positive Helicobacter pylori strains in atherosclerotic stroke patients is associated with greater intima-media thickness and poorer short-term outcome compared with cytotoxin-associated gene-A-negative patients.

Helicobacter pylori duodenal colonization is a strong risk factor for the development of duodenal ulcer

AIM

To test the hypothesis that duodenal colonization represents the final crucial step in the development of Helicobacter pylori related duodenal ulcer.

METHODS

Patients with non-ulcer dyspepsia who had gastric colonization by H. pylori were included in the study. At baseline endoscopy, we evaluated the prevalence of duodenal colonization (culture, urease testing and histology), and cytotoxin-associated gene A status (polymerase chain reaction). No patients received eradication during 1 year follow-up. At this time, endoscopy was repeated and the incidence of duodenal ulcer was assessed.

RESULTS

Among 181 patients completing follow-up, 53 (29%) had duodenal colonization: 72% of them were cytotoxin-associated gene A positive, versus 37% patients without duodenal colonization (P < 0.001). Duodenal ulcer developed in 12 (22.6%) patients with duodenal colonization and in two (1.6%) without duodenal colonization (odds ratio for duodenal ulcer: 6.29, 95% confidence intervals 2.44-17.45). The incidence of duodenal ulcer was similar among cytotoxin-associated gene A positive and cytotoxin-associated gene A negative subjects with duodenal colonization: 21.05% versus 26.6%.

CONCLUSIONS

The assessment of duodenal colonization by H. pylori in patients with non-ulcer dyspepsia is strongly predictive for the subsequent development of duodenal ulcer and may help to stratify patients at risk for this disease.

Abnormal maternal cardiac function precedes the clinical manifestation of fetal growth restriction

OBJECTIVE

To compare maternal hemodynamics in women whose fetuses are small-for-gestational age (SGA) with those in women with fetal growth restriction (FGR) before manifestation of the clinical disease.

METHODS

Thirty-five normotensive pregnant women with fetal abdominal circumference < 10th centile, normal fetal anatomy and normal umbilical artery pulsatility index (PI) underwent maternal echocardiographic examinations between 27 and 30 weeks of gestation. Pregnancies were followed until delivery and fetuses were retrospectively classified as either SGA or FGR and the maternal hemodynamic data were compared.

RESULTS

Nineteen SGA and 16 FGR patients were retrospectively identified after delivery. Heart rate, stroke volume, cardiac output, left atrial function and left ventricular mass index were higher, while mean blood pressure and total vascular resistance were lower in the SGA group compared with the FGR group. A significant inverse linear correlation was found between total vascular resistance and weight centile (r = 0.83; P < 0.0001).

CONCLUSIONS

Mothers of SGA fetuses show hemodynamic features similar to those with physiological pregnancies suggesting that their fetuses are likely to be constitutionally small and not pathologically growth-restricted.

Maternal cardiac systolic function and total body water estimation in normal and gestational hypertensive women

We assessed total body water (TBW) content and cardiac function in 25 normotensive (N) and 22 gestational hypertensive (GH) women matched for age, gestational age, and prepregnancy body mass index (BMI) during the third trimester of gestation. Patients underwent maternal echocardiography, bioelectrical impedance analysis (BIA), and hematocrit (Hct %) evaluation. The TBW:Hct ratio (water balance index, WBI) was calculated. Hct was significantly lower in N vs. GH women (31.9+/-2.2% vs. 36.2+/-2.5; p<0.001). There was no difference in TBW between the two groups. WBI was higher in N vs. GH women (1.35+/-0.20 l.kg(-1) x m(-2) vs. 1.19+/-0.18; p<0.001). N subjects showed a higher stroke volume than GH patients (78.0+/-9.7 ml vs. 67.9+/-10.2; p=0.001). Atrial function was higher in N vs. GH women (left atrial fractional area change 57.4+/-5.1% vs. 42.5+/-7.5; p<0.001). A correlation was found between stroke volume and WBI ( r=0.93, p<0.0001). Maternal cardiac function and WBI are strongly related and might help in understanding the mechanisms of adaptation in normal and hypertensive pregnancy.

Abnormal maternal cardiac function and morphology in pregnancies complicated by intrauterine fetal growth restriction

OBJECTIVE

To explore maternal cardiac function through an echocardiographic evaluation, in a group of nulliparous patients with intrauterine fetal growth restriction during the third trimester of pregnancy.

METHODS

Twenty-one consecutive nulliparous pregnant women who had fetuses with intrauterine growth restriction (IUGR) and abnormal umbilical artery Doppler pulsatility index (PI) underwent maternal echocardiographic examination during the third trimester of gestation. The data were then compared with those obtained from 21 normal nulliparous women who had fetuses with an estimated fetal weight > 10th percentile and a normal umbilical artery Doppler PI who were considered as the control group.

RESULTS

Heart rate was slightly lower in the IUGR group, whereas blood pressure and total vascular resistance were higher compared with the control subjects. End-diastolic volume, stroke volume and cardiac output were lower in the IUGR patients compared with normal patients. The IUGR group had smaller left atrial maximal dimensions and greater left atrial minimal areas compared with the control subjects. Left atrial function was depressed in the IUGR group. A smaller left ventricular mass was present in the IUGR patients compared with the control subjects. Isovolumetric relaxation time (IVRT) was prolonged in the IUGR patients compared with the controls.

CONCLUSIONS

The absence of a 'correct' maternal cardiovascular compensatory response to abnormal trophoblastic invasion, might be one of the factors that slowly determine the conditions of reduced placental perfusion and eventually of the development of fetal growth restriction.

New proposal for numerical simulations of theta-vacuum-like systems

We propose a new approach to perform numerical simulations of theta-vacuum-like systems, test it in two analytically solvable models, and apply it to CP3. The main new ingredient in our approach is the method used to compute the probability distribution function of the topological charge at theta=0. We do not get unphysical phase transitions (flattening behavior of the free energy density) and reproduce the exact analytical results for the order parameter in the whole theta range within a few percent.

Energy metabolism pathways in rat muscle under conditions of simulated microgravity

Evidence from rats flown in space suggests that there is a decrease in the ability of the soleus muscle to oxidize long chain fatty acids during space flight. The observation suggests that a shift in the pathways involved in muscle fuel utilization in the absence of load on the muscle has occurred. It is also possible that the reduction is part of a general down-sizing of metabolic capacity since energy needs of inactive muscle are necessarily less. The rodent hind limb suspension model has proved to be a useful ground based model for studying the musculo-skeletal systems changes that occur with space flight. Microarray technology permits the screening of a large number of the enzymes of the relevant pathways thereby permitting a distinction to be made between a shift fuel utilization pattern or a general decrease in metabolic activity. The soleus muscle was isolated from 5 control and 5 hindlimb suspended rats (21 days) and the Affymetrix system for assessing gene expression used to determine the impact of hindlimb unloading on fuel pathways within the muscle of each animal. RESULTS: Suspended rats failed to gain weight at the same rate as the controls (337 +/- 5 g vs 318 +/- 6 g, p < 0.05) and muscle mass from the soleus was reduced (135 +/- 3 mg vs 48 +/- 4 mg, p < 0.05). There was a consistent decrease (p < 0.05) in gene expression of proteins involved in fatty acid oxidation in the suspended group whereas glycolytic activity was increased (p < 0.05). Gene expressions of individual key regulatory enzymes reflected these changes. Carnitine palmitoyltransferase I and II were decreased (p < 0.05) whereas expression of hexokinase, phosphofructokinase and pyruvate kinase were increased (p < 0.05). CONCLUSION: Disuse atrophy is associated with a change in mRNA levels of enzymes involved in fuel metabolism indicative of a shift in substrate utilization away from fat towards glucose.

DNA microarray analysis of the contused spinal cord: effect of NMDA receptor inhibition

Spinal cord injury (SCI)-induced neurodegeneration leads to irreversible and devastating motor and sensory dysfunction. Post-traumatic outcomes are determined by events occurring during the first 24 hours after SCI. An increase in extracellular glutamate concentration to neurotoxic levels is one of the earliest events after SCI. We used Affymetrix DNA oligonucleotide microarrays (with 1,322 DNA probes) analysis to measure gene expression in order to test the hypothesis that SCI-induced N-methyl-D-aspartate (NMDA) receptor activation triggers significant postinjury transcriptional changes. Here we report that SCI, 1 hour after trauma, induced change in mRNA levels of 165 genes and expression sequence tags (ESTs). SCI affected mRNA levels of those genes that regulate predominantly transcription factors, inflammation, cell survival, and membrane excitability. We also report that NMDA receptor inhibition (with -(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate [MK-801]) reversed the effect of SCI on about 50% of the SCI-affected mRNAs. Especially interesting is the finding that NMDA receptor activation participates in the up-regulation of inflammatory factors. Therefore, SCI-induced NMDA receptor activation is one of the dominant, early signals after trauma that leads to changes in mRNA levels of a number of genes relevant to recovery processes. The majority of MK-801 effects on the SCI-induced mRNA changes reported here are novel. Additionally, we found that the MK-801 treatment also changed the mRNA levels of 168 genes and ESTs that had not been affected by SCI alone, and that some of their gene products could have harmful effects on SCI outcome.

Gene expression profiling of acute spinal cord injury reveals spreading inflammatory signals and neuron loss

We have completed the first large-scale gene expression study of acute spinal cord injury (SCI) in rat. Oligonucleotide microarrays containing 1,200 gene-specific probes were used to quantify mRNA levels, relative to uninjured controls, in spinal cords injured using a standard contusion model. Our results revealed a marked loss of neuron-specific mRNAs at the injury site. The surviving cells showed a characteristic inflammatory response that started at the injury site and spread to the distal cord. Changes in several mRNA levels were associated with putative regenerative responses in the spinal cord. Notably, phosphodiesterase 4, nestin, glia-derived neurite promoting factor, and GAP-43 mRNAs increased significantly. Other mRNAs clustered temporally and spatially with these regeneration-associated genes. Thus we have described global patterns of gene expression following acute SCI, and we have identified targets for future study and possible therapeutic intervention.

Spontaneous baroreflex modulation of heart rate and heart rate variability during orthostatic stress in tetraplegics and healthy subjects

OBJECTIVE

This study was addressed to investigate the contribution of vagal and sympathetic mechanisms to the genesis of low-frequency (LF) oscillations of RR-interval.

DESIGN

To this aim, we utilized the pathophysiological model of tetraplegics, who have intact vagal afferent and efferent pathways of the baroreceptor reflex arc but interrupted medullary-spinal sympathetic pathways.

METHODS

We studied nine complete, traumatic, tetraplegics (C4-C7, TET) and 10 normally healthy subjects (NR) at rest and during physiological baroreceptors unloading induced by 70 degrees head-up tilt. Autoregressive power spectral analysis was used to investigate RR-interval and systolic arterial pressure (SAP) variabilities. Baroreflex modulation of sinus node was assessed by the spontaneous baroreflex sequences method.

RESULTS

Both at-rest and during-tilt LF and high frequency (HF) components were detected in RR-interval of NR, whereas in TET only the HF component was observed in both conditions (with one exception). Baroreflex sensitivity (BRS) did not significantly differ between TET and NR at rest, and underwent a significant and similar decrease during tilt in both groups, being accompanied in NR by a significant increase in LF relative power. Spectral analysis of SAP provided results similar to RR-interval. Tilt also slowed the centre frequency of the LF components of RR-interval and SAP.

CONCLUSIONS

During unperturbed physiological conditions, a change in efferent vagal activity to the heart from baroreflex stimulation by spontaneous arterial pressure changes, is unlikely to contribute on its own to the genesis of LF heart period oscillations in humans who lack the ability to modulate sympathetic nerve traffic to the heart. However, the possibility that a baroreflex modulation of LF oscillations require an intact sympathetic control should be carefully considered.

Maternal diastolic function in asymptomatic pregnant women with bilateral notching of the uterine artery waveform at 24 weeks' gestation: a pilot study

OBJECTIVE

To study second-trimester maternal cardiac adaptation in asymptomatic patients at risk, on the basis of abnormal uterine artery Doppler, for the development of gestational hypertension or having a small-for-gestational age fetus. Fetal and maternal outcomes were verified at the end of pregnancy.

METHODS

Thirty-six normotensive women with abnormal uterine artery waveforms underwent maternal echocardiographic examination at 24 weeks' gestation.

RESULTS

Twenty-one women (58.3%) subsequently showed normal outcome; 12 patients developed gestational hypertension (33.3%) and three (8.3%) had small-for-gestational age newborns. Left ventricular outflow tract, left ventricular diastolic dimensions and atrial and ventricular function were significantly lower in the pathological outcome group. Diastolic function parameters were significantly different between the two groups: peak mitral E-wave and A-wave and A-wave duration showed lower values in the pathological outcome group. Isovolumetric relaxation time of the left ventricle was significantly longer in the pathological outcome group. The prevalence of an altered geometric pattern was 14.3% (3/21) in the normal and 80% (12/15) in the pathological outcome groups (P < 0.001).

CONCLUSIONS

Women who subsequently develop a complication of pregnancy tend to display abnormal cardiac adaptation. An abnormal placentation process, expressed by an elevated resistance index and the presence of notches in the uterine artery waveform, are likely to cause an adaptative mechanism involving the whole cardiovascular system. A pathological outcome of pregnancy is associated with the failure of this process.

C-reactive protein is increased in patients with degenerative aortic valvular stenosis

OBJECTIVES

The goal of this study was to assess the presence of systemic inflammation in degenerative aortic valvular stenosis.

BACKGROUND

Local inflammatory changes, resembling those observed in atherosclerosis, have been recently reported in degenerative aortic valvular stenosis. It is presently unknown whether systemic signs of inflammation, similar to those observed in atherosclerosis, may be present in this disorder.

METHODS

C-reactive protein (CRP) was measured by enzyme immunoassay in 141 subjects: 62 with trileaflet degenerative valvular aortic stenosis and 79 volunteers with similar demographic and clinical characteristics. IgG antibodies against Helicobacter pylori (enzyme-linked immunosorbant assay) and Chlamydia pneumoniae (microimmunofluorescence assay) were also measured.

RESULTS

C-reactive protein levels (mg/dl, mean +/- SD) were 0.848 +/- 1.42 in patients and 0.394 +/- 0.50 in controls (p = 0.0001, Mann-Whitney U test). Seroprevalence of H. pylori was 68.7% in patients and 79.7% in controls (p = NS), whereas seroprevalence of C. pneumoniae infection was higher in patients than it was in controls (59.7% vs. 33%, p = 0.003; chi-square test). After adjustment for various covariates in multiple logistic regression, the odds ratio for degenerative aortic stenosis was 3.41 for C. pneumoniae infection (95% confidence intervals [CI]: 1.60 to 7.30) and 2.76 for CRP (95% CI: 1.08 to 7.05). There was no significant difference in patients or controls in CRP levels according to the serostatus for C. pneumoniae.

CONCLUSIONS

Systemic signs of inflammation, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis. They do not seem to be linked to C. pneumoniae or H. pylori infection.

Maternal diastolic dysfunction and left ventricular geometry in gestational hypertension

The objective of this study was to evaluate diastolic parameters and left ventricular geometry in gestational hypertension. Twenty-one consecutive pregnant women with gestational hypertension and 21 normotensive women matched for age and gestational age were enrolled in the third trimester of gestation. Echocardiographic and uterine color Doppler evaluations were performed. Systolic, diastolic, and mean blood pressure, total vascular resistance (TVR), and uterine resistance index were higher in hypertensive women than in control subjects (P<0.01). Left atrial function and cardiac output were significantly lower in gestational hypertension (P<0.01). Patients with gestational hypertension had longer left ventricular isovolumetric relaxation time (IVRT) (P<0.0001); lower velocity-time integral of the A wave (P<0.05) and of the diastolic pulmonary vein flow (P<0.05); and higher velocity-time integral of the reverse pulmonary vein flow (P<0.05). Systolic fraction of the pulmonary vein flow was higher in women with gestational hypertension than in control subjects (P<0.01); the difference in duration of pulmonary vein flow and A wave was closer to 0 in gestational hypertension (P<0.0001). Altered left ventricular geometry was found in 100% of hypertensive patients and in 19.05% of normotensive patients (P<0.001). IVRT, left ventricular end-systolic volume, atrial function, and uterine resistance index were directly related to TVR (P<0.01); deceleration time of the E wave showed a quadratic correlation with TVR (P<0.01). Gestational hypertension is characterized by an altered cardiac geometric pattern of concentric hypertrophy. The altered geometric pattern assessed during gestational hypertension is associated, in our study, with depressed systolic function, high TVR, altered diastolic function, and left atrial dysfunction. Deceleration time of the E wave, IVRT, and left atrial fractional area change, found in concomitance with the highest TVR, may be useful in the evaluation of cardiac function and hemodynamics present in pregnancy-induced hypertension.

Reduced L-dopa absorption and increased clinical fluctuations in Helicobacter pylori-infected Parkinson's disease patients

We report that the area under the curve of L-dopa plasma concentration, following the administration of a single 250 mg L-dopa dose, is augmented after Helicobacter pylori (HP) eradication in six Parkinson's disease (PD) patients showing high IgG antibody titer against HP. A prolongation of L-dopa clinical benefit was also observed. We suggest that HP infection-activated gastric alterations may be responsible, at least in part, for the reported erratic efficacy of oral L-dopa therapy in some advanced PD patients. Given the high percentage of HP-positivity in the age cohorts including the largest prevalence of PD patients, we propose that HP eradication be recommended in all PD patients under L-dopa therapy.

Effects of a residential exercise training on baroreflex sensitivity and heart rate variability in patients with coronary artery disease: A randomized, controlled study

BACKGROUND

Myocardial ischemia and infarction impair baroreflex sensitivity (BRS), which when depressed is predictive of future cardiac events after myocardial infarction (MI). The main objective of this study was to determine whether exercise training improves BRS in patients with coronary artery disease.

METHODS AND RESULTS

Ninety-seven male patients with and without a previous MI were recruited after myocardial revascularization surgery and randomized into trained (TR) or untrained (UTR) groups. TR patients underwent a residential exercise program at 85% of maximum heart rate (HRmax) consisting of 2 daily sessions 6 times a week for 2 weeks. Eighty-six patients (45 TR and 41 UTR) completed the study. BRS was assessed at baseline and at the end of the protocol by the spontaneous baroreflex method. The standard deviation of mean R-R interval (RRSD) was also assessed as a measure of heart rate variability. At baseline, there were no significant differences between TR and UTR patients in any variable. In TR patients, BRS increased from 3.0+/-0.3 to 5.3+/-0.7 ms/mm Hg (P:<0.001), RRSD from 18.7+/-1.4 to 23.6+/-1.6 ms (P:<0.01), and R-R interval from 792. 0+/-15.5 to 851.3+/-20.5 ms (P:<0.001). No significant changes occurred in UTR patients. Increases in BRS and RRSD were significant in patients either with or without a previous MI.

CONCLUSIONS

Exercise training increases BRS and heart rate variability in patients with coronary artery disease. Improved cardiac autonomic function might add to the other benefits of exercise training in secondary prevention of ischemic heart disease.

Cytotoxin-associated gene A and vacuolating cytotoxin A in human isolates of Helicobacter pylori and their association with the clinical status of ulcer disease

OBJECTIVE

The aim of this study was to evaluate whether different Helicobacter pylori genotypes are associated with different clinical stages of peptic ulcer disease (PUD).

DESIGN

We assessed the virulence characteristics of H. pylori isolates from patients with active PUD (presence of an ulcer crater at endoscopy) and from those with PUD in remission (normal endoscopic findings or scar not induced by drugs in PUD patients).

METHODS

H. pylori isolates from biopsies of the gastric antrum were examined for cagA and vacA genotypes by PCR amplification and Western blot analysis. Descriptive statistical techniques and multivariate polytomous logistic regression were used to estimate adjusted odds ratio (OR) for cagA and vacA genotypes in patients with active PUD or PUD in remission. Patients with non-ulcer dyspepsia (NUD) were used as negative controls.

RESULTS

The cagA genotype and phenotype were found to be differently associated with disease status. In fact, the multivariate regression model showed that gastric colonization by CagA+ H. pylori strains was associated with an increased risk of active PUD (OR 2.58), whereas the OR for patients with PUD in remission was 0.94.

CONCLUSIONS

Our data indicate that the active ulcer status is more strongly associated with H. pylori strains carrying the pathogenicity island (PAI) than remission status. These results support the hypothesis that a dynamic equilibrium exists among bacterial populations with or without the PAI, and that the relapse of the peptic ulcer could be consequent to expansion of the H. pylori population carrying the PAI.

Incidence and risk factors associated with cardiac arrhythmias during rehabilitation after coronary artery bypass surgery

OBJECTIVE

To evaluate the clinical relevance of cardiac arrhythmias during rehabilitation after coronary artery bypass graft (CABG) surgery.

DESIGN

Survey of consecutive patients admitted to an inpatient cardiac rehabilitation center.

SETTING

A rehabilitation center acting as a reference for cardiology clinics lacking this facility. The program was performed in the inpatient setting.

PATIENTS

Two hundred sixty patients undergoing elective CABG surgery for angina.

INTERVENTIONS

Four-week cardiac rehabilitation program. A 24-hour electrocardiographic examination was performed during the first 2 days and, subsequently, on a daily basis.

MAIN OUTCOME MEASURES

Incidence and type of cardiac arrhythmias during rehabilitation; identification of factors associated with an increased risk of cardiac arrhythmias.

RESULTS

Cardiac arrhythmias were recorded in 33.5% of the patients and were more frequent in patients with hypertension (47%), diabetes (42.4%), and hyperlipidemia (36.5%), compared with patients free from these diseases (15.5%) (p < .05). Arrhythmias were also recorded in patients older than 70 years (49%), compared with those younger (29.2%) (p < .01), and in patients who discontinued amiodarone (64.3%) compared with those who did not interrupt the drug (16%) (p < .005). Arrhythmias precluded rehabilitation in 5% of the patients and caused death in one patient.

CONCLUSION

Surveillance for the development of cardiac arrhythmias during cardiac rehabilitation after CABG surgery may allow the early detection and treatment of arrhythmias in a substantial number of patients.

Maternal cardiac systolic and diastolic function: relationship with uteroplacental resistances. A Doppler and echocardiographic longitudinal study

OBJECTIVE

To test the hypothesis of the existence of a relationship between central and peripheral hemodynamic parameters by the longitudinal evaluation of maternal echocardiographic and uteroplacental resistance modifications during normal pregnancy.

METHODS

Forty-three healthy normotensive primigravidae were evaluated at 12 +/- 1, 21 +/- 1, and 33 +/- 1 weeks of gestation with uterine artery color Doppler and maternal echocardiographic examinations to identify morphologic, systolic, and diastolic variables.

RESULTS

Cardiac output and stroke volume significantly increased during pregnancy. Uterine resistance index (RI) decreased from the first to the second trimesters (0.72 +/- 0.10 versus 0.54 +/- 0.09, P < 0.001). Left atrial dimensions increased during pregnancy (33.8 +/- 1.9 cm, 38.1 +/- 1.8 cm, 39.3 +/- 2.1 cm, P < 0.001). Left atrial function also increased. Left ventricular mass increased (132 +/- 18 g, 162 +/- 16 g, 174 +/- 27 g, P < 0.001). Diastolic function parameters showed significant modifications: E wave velocity and E/A ratio decreased; A wave velocity and deceleration time of the E wave (DtE) increased; the left ventricular isovolumetric relaxation time (IVRT) decreased significantly (88.7 +/- 6.7 ms, 75.6 +/- 7.7 ms, 71.1 +/- 5.0 ms, P < 0.001) showing a correlation with left atrial dimensions and RI (r = -0.38, r = 0.47, respectively; P < 0.001).

CONCLUSIONS

Diastolic cardiac function varies during pregnancy. A relationship between preload (left atrial enlargement), afterload (RI reduction), morphologic, and diastolic function modifications (IVRT reduction, DtE prolongation) appears to exist as a consequence of the hemodynamic modifications which occur during physiologic pregnancy. Diastolic function analysis maybe useful to identify women who fully adapt to pregnancy, and to understand the mechanisms that might be involved in women who show abnormal uterine artery Doppler waveforms.

Infection with Helicobacter pylori and leukocyte response in patients with myocardial infarction

To test whether Helicobacter pylori may contribute to the inflammatory response following myocardial infarction, the levels of IgG antibodies to Helicobacter pylori and some parameters of leukocyte activity were measured in 63 patients and 61 comparable controls. Helicobacter pylori-positive patients showed a significantly higher expression of the adhesion molecule LFA-1 on neutrophils than Helicobacter pylori-negative patients (433+/-29.0 vs. 398.8+/-38.9 mean fluorescence channels; P<0.0001), whereas no significant difference for any parameters tested was found in control subjects. These data suggest a role of Helicobacter pylori in inducing a leukocyte response following myocardial infarction.

Leukocyte count and aggregation during the evolution of cerebral ischemic injury

We evaluated leukocyte aggregation by means of the leukergy test and count in 26 patients with atherothrombotic stroke and in 10 patients with transient ischemic attacks. The evaluation was performed within 24 h from the onset of symptoms and then repeated on day 2, 4, 6 and 8. Data were compared with those of 10 healthy controls. Stroke patients were followed until day 30 when a clinical examination and brain computed tomography were performed to evaluate the extent and outcome of cerebral damage. Both leukocyte aggregation and count were significantly increased in stroke patients with respect to controls. While leukocyte count was not able to differentiate the severity of neurological impairment in stroke patients, leukocyte aggregation was significantly higher in major than in minor stroke patients on days 2 and 4 (p < 0.05). Moreover, while values of leukocyte count recorded at entry remained substantially stable in the following determinations in all groups, leukocyte aggregation showed a significant increase (p < 0.05) on day 4 with respect to all the other determinations in major stroke patients. These findings show that the extent and temporal profile of changes in leukocyte count and aggregation are different in patients with cerebrovascular disease and suggest an involvement of altered leukocyte rheology in the development of cerebral ischemic injury.

Mild brain ischemia increases cerebral lipid peroxidation and activates leukocytes in the peripheral blood of rats

This study evaluated local and systemic leukocyte changes, respectively in the jugular and femoral veins, after an acute reduction of cerebral blood flow (oligoemia) in rats submitted either to permanent bilateral carotid occlusion (BCO) (no. = 36) for 5 hours or to sham operation (no. = 33). In a subgroup of rats (no. = 13) the extent of neural damage was histologically assessed. As a marker of biochemical brain changes the entity of the iron-ascorbate induced lipid peroxidation of synaptosomes was assessed in vitro by measuring malondialdehyde (MDA) reactive products. Five hours after surgery, the percentage of aggregated leukocytes and of activated neutrophils reducing the NBT were significantly higher in BCO rats (p < 0.05). However, leukocyte changes did not differ significantly between the jugular and the femoral districts. The brains of BCO rats showed tiny foci of neuronal necrosis. Synaptosomes obtained from the BCO animals showed a small but highly significant increase of MDA production (p < 0.01). Long-lasting brain oligoemia increases the production of lipid peroxidative metabolites, and causes the occurrence of tiny foci of neuronal necrosis in different brain regions. The lack of a significant gradient in aggregated leukocytes and activated neutrophils between the jugular and femoral venous districts demonstrates that leukocytes are stimulated in the peripheral blood by even mild biochemical and morphological brain damage.

Leucocyte rheological properties are altered in patients with diffuse atherosclerosis

To evaluate whether atherosclerosis may be associated with altered leucocyte rheology, we assessed leucocyte count (by Coulter counter), aggregation (by means of the leukergy test) and expression of adhesion molecules integrin LFA-1 and CD 44 (by means of immunofluorescence staining and flow cytometry) in 9 patients with carotid plus lower limb artery atherosclerosis (group A), 14 patients with carotid atherosclerosis only (group B) and 23 controls without atherosclerosis (group C). The level of LFA-1 (calculated as mean fluorescence channels-MFCs) on neutrophils, lymphocytes and monocytes was significantly higher (p < 0.05) in group A and B patients than in controls (group A-mean +/- SE: 383.77 +/- 9.42 vs 295.45 +/- 5.76; 474.22 +/- 8.86 vs 388.35 +/- 7.84; 457.66 +/- 12.03 vs 396.25 +/- 4.37. Group B: 322.42 +/- 6.36 vs 295.45 +/- 5.76; 421.42 +/- 7.21 vs 388.35 +/- 7.84; 415.71 +/- 7.73 vs 396.25 +/- 4.37, respectively); furthermore, the MFC of LFA-1 on neutrophils was significantly different (p < 0.05) between group A and B patients. The percentage of aggregated leucocytes was significantly higher (p < 0.05) in group A patients (4.46 +/- 1.07) than those in groups B (1.75 +/- 0.38) and C (1.43 +/- 0.25), whereas no significant difference was detected between groups B and C. Leucocyte number and expression of CD44 were not significantly different among the 3 groups. In conclusion, changes in leucocyte rheology are present in patients with atherosclerosis and may contribute to chronic ischaemia.