Adult Cerebral Malaria: Acute and Subacute Imaging Findings, Long-term Clinical Consequences

Cerebral malaria is an important cause of mortality and neurodisability in endemic regions. We show magnetic resonance imaging (MRI) features suggestive of cytotoxic and vasogenic cerebral edema followed by microhemorrhages in 2 adult UK cases, comparing them with an Indian cohort. Long-term follow-up images correlate ongoing changes with residual functional impairment.

Neuroimaging findings in 4342 hospitalized COVID-19 subjects: A multicenter report from the United States and Europe

BACKGROUND AND PURPOSE

To determine the incidence of acute neuroimaging (NI) findings and comorbidities in the coronavirus disease of 2019 (COVID-19)-infected subjects in seven U.S. and four European hospitals.

METHODS

This is a retrospective study of COVID-19-positive subjects with the following inclusion criteria: age >18, lab-confirmed COVID-19 infection, and acute NI findings (NI+) attributed to COVID-19 on CT or MRI brain. NI+ and comorbidities in total hospitalized COVID-19-positive (TN) subjects were assessed.

RESULTS

A total of 37,950 COVID-19-positive subjects were reviewed and 4342 underwent NI. NI+ incidence in subjects with NI was 10.1% (442/4342) including 7.9% (294/3701) in the United States and 22.8% (148/647) in Europe. NI+ incidence in TN was 1.16% (442/37,950). In NI (4342), incidence of ischemic stroke was 6.4% followed by intracranial hemorrhage (ICH) (3.8%), encephalitis (0.5%), sinus venous thrombosis (0.2%), and acute disseminated encephalomyelitis (ADEM) (0.2%). White matter involvement was seen in 57% of NI+. Hypertension was the most common comorbidity (54%) before cardiac disease (28.8%) and diabetes mellitus (27.7%). Cardiac disease (p < .025), diabetes (p < .014), and chronic kidney disease (p < .012) were more common in the United States.

CONCLUSION

This multicenter, multinational study investigated the incidence and spectrum of NI+ in 37,950 hospitalized adult COVID-19 subjects including regional differences in incidences of NI+, associated comorbidities, and other demographics. NI+ incidence in TN was 1.16% including 0.95% in the United States and 2.09% in Europe. ICH, encephalitis, and ADEM were common in Europe, while ischemic strokes were more common in the United States. In this cohort, incidence and distribution of NI+ helped characterize the neurological complications of COVID-19.

Imaging Approach to Venous Sinus Thrombosis

Cerebral venous thrombosis (CVT) is a rare cerebrovascular disease caused by an occlusion of the cerebral venous sinuses or cortical veins. It has a favorable prognosis if diagnosed and treated early. CVT can be difficult to diagnose on clinical grounds, and imaging plays a key role. We discuss clinical features and provide an overview of current neuroimaging methods and findings in CTV.

Antiphospholipid antibodies and neurological manifestations in acute COVID-19: A single-centre cross-sectional study

BACKGROUND

A high prevalence of antiphospholipid antibodies has been reported in case series of patients with neurological manifestations and COVID-19; however, the pathogenicity of antiphospholipid antibodies in COVID-19 neurology remains unclear.

METHODS

This single-centre cross-sectional study included 106 adult patients: 30 hospitalised COVID-neurological cases, 47 non-neurological COVID-hospitalised controls, and 29 COVID-non-hospitalised controls, recruited between March and July 2020. We evaluated nine antiphospholipid antibodies: anticardiolipin antibodies [aCL] IgA, IgM, IgG; anti-beta-2 glycoprotein-1 [aβ2GPI] IgA, IgM, IgG; anti-phosphatidylserine/prothrombin [aPS/PT] IgM, IgG; and anti-domain I β2GPI (aD1β2GPI) IgG.

FINDINGS

There was a high prevalence of antiphospholipid antibodies in the COVID-neurological (73.3%) and non-neurological COVID-hospitalised controls (76.6%) in contrast to the COVID-non-hospitalised controls (48.2%). aPS/PT IgG titres were significantly higher in the COVID-neurological group compared to both control groups (p < 0.001). Moderate-high titre of aPS/PT IgG was found in 2 out of 3 (67%) patients with acute disseminated encephalomyelitis [ADEM]. aPS/PT IgG titres negatively correlated with oxygen requirement (FiO2 R=-0.15 p = 0.040) and was associated with venous thromboembolism (p = 0.043). In contrast, aCL IgA (p < 0.001) and IgG (p < 0.001) was associated with non-neurological COVID-hospitalised controls compared to the other groups and correlated positively with d-dimer and creatinine but negatively with FiO2.

INTERPRETATION

Our findings show that aPS/PT IgG is associated with COVID-19-associated ADEM. In contrast, aCL IgA and IgG are seen much more frequently in non-neurological hospitalised patients with COVID-19. Characterisation of antiphospholipid antibody persistence and potential longitudinal clinical impact are required to guide appropriate management.

FUNDING

This work is supported by UCL Queen Square Biomedical Research Centre (BRC) and Moorfields BRC grants (#560441 and #557595). LB is supported by a Wellcome Trust Fellowship (222102/Z/20/Z). RWP is supported by an Alzheimer's Association Clinician Scientist Fellowship (AACSF-20-685780) and the UK Dementia Research Institute. KB is supported by the Swedish Research Council (#2017-00915) and the Swedish state under the agreement between the Swedish government and the County Councils, the ALF-agreement (#ALFGBG-715986). HZ is a Wallenberg Scholar supported by grants from the Swedish Research Council (#2018-02532), the European Research Council (#681712), Swedish State Support for Clinical Research (#ALFGBG-720931), the Alzheimer Drug Discovery Foundation (ADDF), USA (#201809-2016862), and theUK Dementia Research Institute at UCL. BDM is supported by grants from the MRC/UKRI (MR/V007181/1), MRC (MR/T028750/1) and Wellcome (ISSF201902/3). MSZ, MH and RS are supported by the UCL/UCLH NIHR Biomedical Research Centre and MSZ is supported by Queen Square National Brain Appeal.

Serum and cerebrospinal fluid biomarker profiles in acute SARS-CoV-2-associated neurological syndromes

Preliminary pathological and biomarker data suggest that SARS-CoV-2 infection can damage the nervous system. To understand what, where and how damage occurs, we collected serum and CSF from patients with COVID-19 and characterized neurological syndromes involving the PNS and CNS (n = 34). We measured biomarkers of neuronal damage and neuroinflammation, and compared these with non-neurological control groups, which included patients with (n = 94) and without (n = 24) COVID-19. We detected increased concentrations of neurofilament light, a dynamic biomarker of neuronal damage, in the CSF of those with CNS inflammation (encephalitis and acute disseminated encephalomyelitis) [14 800 pg/ml (400, 32 400)], compared to those with encephalopathy [1410 pg/ml (756, 1446)], peripheral syndromes (Guillain-Barré syndrome) [740 pg/ml (507, 881)] and controls [872 pg/ml (654, 1200)]. Serum neurofilament light levels were elevated across patients hospitalized with COVID-19, irrespective of neurological manifestations. There was not the usual close correlation between CSF and serum neurofilament light, suggesting serum neurofilament light elevation in the non-neurological patients may reflect peripheral nerve damage in response to severe illness. We did not find significantly elevated levels of serum neurofilament light in community cases of COVID-19 arguing against significant neurological damage. Glial fibrillary acidic protein, a marker of astrocytic activation, was not elevated in the CSF or serum of any group, suggesting astrocytic activation is not a major mediator of neuronal damage in COVID-19.

The emerging spectrum of COVID-19 neurology: clinical, radiological and laboratory findings

Preliminary clinical data indicate that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with neurological and neuropsychiatric illness. Responding to this, a weekly virtual coronavirus disease 19 (COVID-19) neurology multi-disciplinary meeting was established at the National Hospital, Queen Square, in early March 2020 in order to discuss and begin to understand neurological presentations in patients with suspected COVID-19-related neurological disorders. Detailed clinical and paraclinical data were collected from cases where the diagnosis of COVID-19 was confirmed through RNA PCR, or where the diagnosis was probable/possible according to World Health Organization criteria. Of 43 patients, 29 were SARS-CoV-2 PCR positive and definite, eight probable and six possible. Five major categories emerged: (i) encephalopathies (n = 10) with delirium/psychosis and no distinct MRI or CSF abnormalities, and with 9/10 making a full or partial recovery with supportive care only; (ii) inflammatory CNS syndromes (n = 12) including encephalitis (n = 2, para- or post-infectious), acute disseminated encephalomyelitis (n = 9), with haemorrhage in five, necrosis in one, and myelitis in two, and isolated myelitis (n = 1). Of these, 10 were treated with corticosteroids, and three of these patients also received intravenous immunoglobulin; one made a full recovery, 10 of 12 made a partial recovery, and one patient died; (iii) ischaemic strokes (n = 8) associated with a pro-thrombotic state (four with pulmonary thromboembolism), one of whom died; (iv) peripheral neurological disorders (n = 8), seven with Guillain-Barré syndrome, one with brachial plexopathy, six of eight making a partial and ongoing recovery; and (v) five patients with miscellaneous central disorders who did not fit these categories. SARS-CoV-2 infection is associated with a wide spectrum of neurological syndromes affecting the whole neuraxis, including the cerebral vasculature and, in some cases, responding to immunotherapies. The high incidence of acute disseminated encephalomyelitis, particularly with haemorrhagic change, is striking. This complication was not related to the severity of the respiratory COVID-19 disease. Early recognition, investigation and management of COVID-19-related neurological disease is challenging. Further clinical, neuroradiological, biomarker and neuropathological studies are essential to determine the underlying pathobiological mechanisms that will guide treatment. Longitudinal follow-up studies will be necessary to ascertain the long-term neurological and neuropsychological consequences of this pandemic.

Occupational transmission of an Orthopoxvirus infection during an outbreak in a colony of Macaca tonkeana in Lazio Region, Italy, 2015

Orthopoxviruses spill over from animal reservoirs to accidental hosts, sometimes causing human infections. We describe the surveillance and infection control measures undertaken during an outbreak due to an Orthopoxvirus occurred in January 2015 in a colony of Macaca tonkeana in the province of Rieti, Latio, Italy, which caused a human asymptomatic infection. According to the epidemiological investigation, the human transmission occurred after an unprotected exposure. The contacts among wild, captive and domestic animals and humans, together with decreased immunity against Orthopoxviruses in the community, may put animal handlers at risk of infection, especially after the cessation of smallpox vaccination. To reduce these threats, standard precautions including respiratory hygiene and transmission‐based precautions should be carefully applied also in veterinary medicine.

Genome-wide discovered psychosis-risk gene ZNF804A impacts on white matter microstructure in health, schizophrenia and bipolar disorder

Background. Schizophrenia (SZ) and bipolar disorder (BD) have both been associated with reduced microstructural white matter integrity using, as a proxy, fractional anisotropy (FA) detected using diffusion tensor imaging (DTI). Genetic susceptibility for both illnesses has also been positively correlated in recent genome-wide association studies with allele A (adenine) of single nucleotide polymorphism (SNP) rs1344706 of the ZNF804A gene. However, little is known about how the genomic linkage disequilibrium region tagged by this SNP impacts on the brain to increase risk for psychosis. This study aimed to assess the impact of this risk variant on FA in patients with SZ, in those with BD and in healthy controls. Methods. 230 individuals were genotyped for the rs1344706 SNP and underwent DTI. We used tract-based spatial statistics (TBSS) followed by an analysis of variance, with threshold-free cluster enhancement (TFCE), to assess underlying effects of genotype, diagnosis and their interaction, on FA. Results. As predicted, statistically significant reductions in FA across a widely distributed brain network (p < 0.05, TFCE-corrected) were positively associated both with a diagnosis of SZ or BD and with the double (homozygous) presence of the ZNF804A rs1344706 risk variant (A). The main effect of genotype was medium (d = 0.48 in a 44,054-voxel cluster) and the effect in the SZ group alone was large (d = 1.01 in a 51,260-voxel cluster), with no significant effects in BD or controls, in isolation. No areas under a significant diagnosis by genotype interaction were found. Discussion. We provide the first evidence in a predominantly Caucasian clinical sample, of an association between ZNF804A rs1344706 A-homozygosity and reduced FA, both irrespective of diagnosis and particularly in SZ (in overlapping brain areas). This suggests that the previously observed involvement of this genomic region in psychosis susceptibility, and in impaired functional connectivity, may be conferred through it inducing abnormalities in white matter microstructure.

Sensory gating deficits in the attenuated psychosis syndrome

BACKGROUND

Individuals with an "Attenuated Psychosis Syndrome" (APS) have a 20-40% chance of developing a psychotic disorder within two years; however it is difficult to predict which of them will become ill on the basis of their clinical symptoms alone. We examined whether P50 gating deficits could help to discriminate individuals with APS and also those who are particularly likely to make a transition to psychosis.

METHOD

36 cases meeting PACE (Personal Assessment and Crisis Evaluation) criteria for the APS, all free of antipsychotics, and 60 controls performed an auditory conditioning-testing experiment while their electroencephalogram was recorded. The P50 ratio and its C-T difference were compared between groups. Subjects received follow-up for up to 2 years to determine their clinical outcome.

RESULTS

The P50 ratio was significantly higher and C-T difference lower in the APS group compared to controls. Of the individuals with APS who completed the follow-up (n=36), nine (25%) developed psychosis. P50 ratio and the C-T difference did not significantly differ between those individuals who developed psychosis and those who did not within the APS group.

CONCLUSION

P50 deficits appear to be associated with the pre-clinical phase of psychosis. However, due to the limitations of the study and its sample size, replication in an independent cohort is necessary, to clarify the role of P50 deficits in illness progression and whether this inexpensive and non-invasive EEG marker could be of clinical value in the prediction of psychosis outcomes amongst populations at risk.

The hubs of the human connectome are generally implicated in the anatomy of brain disorders

Brain networks or 'connectomes' include a minority of highly connected hub nodes that are functionally valuable, because their topological centrality supports integrative processing and adaptive behaviours. Recent studies also suggest that hubs have higher metabolic demands and longer-distance connections than other brain regions, and therefore could be considered biologically costly. Assuming that hubs thus normally combine both high topological value and high biological cost, we predicted that pathological brain lesions would be concentrated in hub regions. To test this general hypothesis, we first identified the hubs of brain anatomical networks estimated from diffusion tensor imaging data on healthy volunteers (n = 56), and showed that computational attacks targeted on hubs disproportionally degraded the efficiency of brain networks compared to random attacks. We then prepared grey matter lesion maps, based on meta-analyses of published magnetic resonance imaging data on more than 20 000 subjects and 26 different brain disorders. Magnetic resonance imaging lesions that were common across all brain disorders were more likely to be located in hubs of the normal brain connectome (P < 10(-4), permutation test). Specifically, nine brain disorders had lesions that were significantly more likely to be located in hubs (P < 0.05, permutation test), including schizophrenia and Alzheimer's disease. Both these disorders had significantly hub-concentrated lesion distributions, although (almost completely) distinct subsets of cortical hubs were lesioned in each disorder: temporal lobe hubs specifically were associated with higher lesion probability in Alzheimer's disease, whereas in schizophrenia lesions were concentrated in both frontal and temporal cortical hubs. These results linking pathological lesions to the topological centrality of nodes in the normal diffusion tensor imaging connectome were generally replicated when hubs were defined instead by the meta-analysis of more than 1500 task-related functional neuroimaging studies of healthy volunteers to create a normative functional co-activation network. We conclude that the high cost/high value hubs of human brain networks are more likely to be anatomically abnormal than non-hubs in many (if not all) brain disorders.

Alterations in white matter evident before the onset of psychosis

BACKGROUND

Psychotic disorders are associated with widespread reductions in white matter (WM) integrity. However, the stage at which these abnormalities first appear and whether they are correlates of psychotic illness, as opposed to an increased vulnerability to psychosis, is unclear. We addressed these issues by using diffusion tensor imaging (DTI) to study subjects at ultra high risk (UHR) of psychosis before and after the onset of illness.

METHODS

Thirty-two individuals at UHR for psychosis, 32 controls, and 15 patients with first-episode schizophrenia were studied using DTI. The UHR subjects and controls were re-scanned after 28 months. During this period, 8 UHR subjects had developed schizophrenia. Between-group differences in fractional anisotropy (FA) and diffusivity were evaluated cross sectionally and longitudinally using a nonparametric voxel-based analysis.

RESULTS

At baseline, WM DTI properties were significantly different between the 3 groups (P < .001). Relative to controls, first-episode patients showed widespread reductions in FA and increases in diffusivity. DTI indices in the UHR group were intermediate relative to those in the other 2 groups. Longitudinal analysis revealed a significant group by time interaction in the left frontal WM (P < .001). In this region, there was a progressive reduction in FA in UHR subjects who developed psychosis that was not evident in UHR subjects who did not make a transition.

CONCLUSIONS

People at UHR for psychosis show alterations in WM qualitatively similar to, but less severe than, those in patients with schizophrenia. The onset of schizophrenia may be associated with a progressive reduction in the integrity of the frontal WM.

White matter alterations related to P300 abnormalities in individuals at high risk for psychosis: an MRI-EEG study

BACKGROUND

Psychosis onset is characterized by white matter and electrophysiologic abnormalities. The relation between these factors in the development of illness is almost unknown. We studied the relation between white matter volumes and P300 in prodromal psychosis.

METHODS

We assessed white matter volume (detected using magnetic resonance imaging) and electrophysiologic response during an oddball task (P300) in healthy controls and individuals at high clinical risk for psychosis (with an "at-risk mental state" [ARMS]).

RESULTS

We included 41 controls and 39 patients with an ARMS in our study. A psychotic disorder developed in 26% of the ARMS group within the follow-up period of 2 years. The P300 amplitude was significantly lower in the ARMS group than in the control group. The ARMS group showed reduced volume of white matter underlying the left superior temporal gyrus and the left superior frontal gyrus and increased volume of white matter underlying the right insula and the right angular gyrus compared with controls. Relative to individuals who did not later become psychotic, the subgroup in whom psychosis subsequently developed had a smaller volume of white matter underlying the left precuneus and the right middle temporal gyrus and increased volume in the white matter underlying the right middle frontal gyrus. We observed a significant interaction in the right middle frontal gyrus: white matter volume was negatively associated with P300 amplitude in the ARMS group and positively associated with P300 amplitude in the control group.

LIMITATIONS

The voxel-based morphometry method alone cannot determine whether abnormal white matter volumes are due to an altered number of axonal connections or decreased myelination.

CONCLUSION

P300 abnormalities precede the onset of psychosis and are directly related to white matter alterations, representing a correlate of an increased vulnerability to disease.

Recent expansion of dengue virus serotype 3 in West Africa

Due to non-existing or limited surveillance in Africa, little is known about the epidemiology of dengue illness in the continent. Serological and virological data obtained from returning European travellers is a key complement to this often flawed information. In the past years, dengue 3 virus has emerged in West Africa and has been detected in travellers returning to Europe. The first dengue epidemic in Cape Verde with more than 17,000 cases from September to December 2009 demonstrated that dengue virus is still expanding worldwide to new territories.

Recent expansion of dengue virus serotype 3 in West Africa

Due to non-existing or limited surveillance in Africa, little is known about the epidemiology of dengue illness in the continent. Serological and virological data obtained from returning European travellers is a key complement to this often flawed information. In the past years, dengue 3 virus has emerged in West Africa and has been detected in travellers returning to Europe. The first dengue epidemic in Cape Verde with more than 17,000 cases from September to December 2009 demonstrated that dengue virus is still expanding worldwide to new territories.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

Functional atlas of emotional faces processing: a voxel-based meta-analysis of 105 functional magnetic resonance imaging studies

BACKGROUND

Most of our social interactions involve perception of emotional information from the faces of other people. Furthermore, such emotional processes are thought to be aberrant in a range of clinical disorders, including psychosis and depression. However, the exact neurofunctional maps underlying emotional facial processing are not well defined.

METHODS

Two independent researchers conducted separate comprehensive PubMed (1990 to May 2008) searches to find all functional magnetic resonance imaging (fMRI) studies using a variant of the emotional faces paradigm in healthy participants. The search terms were: "fMRI AND happy faces," "fMRI AND sad faces," "fMRI AND fearful faces," "fMRI AND angry faces," "fMRI AND disgusted faces" and "fMRI AND neutral faces." We extracted spatial coordinates and inserted them in an electronic database. We performed activation likelihood estimation analysis for voxel-based meta-analyses.

RESULTS

Of the originally identified studies, 105 met our inclusion criteria. The overall database consisted of 1785 brain coordinates that yielded an overall sample of 1600 healthy participants. Quantitative voxel-based meta-analysis of brain activation provided neurofunctional maps for 1) main effect of human faces; 2) main effect of emotional valence; and 3) modulatory effect of age, sex, explicit versus implicit processing and magnetic field strength. Processing of emotional faces was associated with increased activation in a number of visual, limbic, temporoparietal and prefrontal areas; the putamen; and the cerebellum. Happy, fearful and sad faces specifically activated the amygdala, whereas angry or disgusted faces had no effect on this brain region. Furthermore, amygdala sensitivity was greater for fearful than for happy or sad faces. Insular activation was selectively reported during processing of disgusted and angry faces. However, insular sensitivity was greater for disgusted than for angry faces. Conversely, neural response in the visual cortex and cerebellum was observable across all emotional conditions.

LIMITATIONS

Although the activation likelihood estimation approach is currently one of the most powerful and reliable meta-analytical methods in neuroimaging research, it is insensitive to effect sizes.

CONCLUSION

Our study has detailed neurofunctional maps to use as normative references in future fMRI studies of emotional facial processing in psychiatric populations. We found selective differences between neural networks underlying the basic emotions in limbic and insular brain regions.

Reduced fractional anisotropy of corpus callosum in first-contact, antipsychotic drug-naive patients with schizophrenia

BACKGROUND

Corpus callosum is the most important commissure of the brain and therefore represents a first-choice candidate to challenge hypotheses of disrupted inter-hemispheric connectivity and white matter pathology in patients with schizophrenia. Recent studies on diffusion tensor imaging (DTI) of corpus callosum yielded promising but equivocal evidence of reduced fractional anisotropy (FA) in schizophrenia patients who were, for the most part, chronic cases on medication for a lengthy period of time. To exclude potentially confounding effects of the course of the disorder and its treatment, we compared callosal FA of first-contact, antipsychotic drug-naive schizophrenia patients (n=21) and healthy controls (n=21).

METHODS

Splenium and genu FA were obtained by two independent observers utilizing large, rectangular, tractography-guided regions of interest outlined on directional color-coded maps. Inter-observer agreement on FA was evaluated by means of the Bland and Altman and the Passing and Bablok procedures together with an estimate of the intra-class correlation coefficient.

RESULTS

Strong inter-observer agreement of FA values emerged from each of the three statistical approaches utilized. ANCOVA showed a significant effect on FA for the interaction between patient-control membership and callosal region (F=5.354; p=0.026); post hoc multiple comparisons demonstrated that, when compared to the controls, the patients had lower mean FA values (p=0.005) in the splenium but not in the genu and that this difference tended to be more evident in males (p=0.090).

CONCLUSIONS

Lowered mean FA values in the splenium of first-contact, antipsychotic drug-naive patients with respect to healthy controls strongly support the hypothesis that processes operant at least since the earliest phases of the disorder and independent from exposition to antipsychotic drugs contribute to reduced anisotropy in schizophrenia.

Laterality effect on emotional faces processing: ALE meta-analysis of evidence

Recognizing emotion from facial expressions draws on diverse psychological processes implemented in a large array of neural structures. Two major theories of cerebral lateralization of emotional perception have been proposed: (i) the Right-Hemisphere Hypothesis (RHH) and (ii) the Valence-Specific Hypothesis (VSH). To test these lateralization models we conducted a large voxel-based meta-analysis of current functional magnetic resonance imaging (fMRI) studies employing emotional faces paradigms in healthy volunteers. Two independent researchers conducted separate comprehensive PUBMED (1990-May 2008) searches to find all functional magnetic resonance imaging studies using a variant of the emotional faces paradigm in healthy subjects. Out of the 551 originally identified studies, 105 studies met inclusion criteria. The overall database consisted of 1785 brain coordinates which yield an overall sample of 1600 healthy subjects. We found no support for the hypothesis of overall right-lateralization of emotional processing. Conversely, across all emotional conditions the parahippocampal gyrus and amygdala, fusiform gyrus, lingual gyrus, precuneus, inferior and middle occipital gyrus, posterior cingulated, middle temporal gyrus, inferior frontal and superior frontal gyri were activated bilaterally (p=0.001). There was a valence-specific lateralization of brain response during negative emotions processing in the left amygdala (p=0.001). Significant interactions between the approach and avoidance dimensions and prefrontal response were observed (p=0.001).

Involvement of nitric oxide-soluble guanylyl cyclase pathway in the control of maximal dentate gyrus activation in the rat

Nitric oxide/soluble Guanylyl cyclase (NO/sGC) pathway on the maximal dentate gyrus activation (MDA) was studied in rats. The cerebral NO levels were modified by administrating 7-Nitroindazole (7-NI), a selective inhibitor of neuronal NOS, and L-arginine, a precursor of the synthesis of NO. 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ), a specific inhibitor of the NO-sGC pathway, was administered to study the involvement of cGMP pathway. The epileptic activity of the dentate gyrus was obtained through the repetitive stimulation of the angular bundle; MDA parameters studied were: onset time, MDA duration and post-stimulus afterdischarge (AD) duration. 7-NI caused an increase of MDA onset time and a decrease of MDA and AD duration. L-arginine, induced an aggravation of the epileptiform phenomena. ODQ induced modifications of MDA parameters as those caused by 7-NI. Our results indicate that the nitrergic neurotransmission exerts a modulatory role in the proneness to the epileptogenic phenomena through the activation of sGC metabolic pathway.

Infection with Human Herpesvirus Type 8 and Kaposi’s Sarcoma in Sardinia

BACKGROUND

A cross-sectional study was conducted in the provinces of Sassari (northern Sardinia, covered by a population-based cancer registry), and of Cagliari (southern Sardinia) to estimate the prevalence of infection with human herpesvirus type 8 (HHV8) and the incidence of classic Kaposi's sarcoma (KS) among HHV8-infected individuals.

PATIENTS AND METHODS

Sera from 297 hospitalized persons potentially at risk of developing classic KS (i. e., those aged 50 years or older) were tested for antibodies against HHV8. HHV8 seroprevalence rates (with 95% confidence intervals-CI) and yearly incidence rates (IR/100,000) of KS were calculated according to age and sex.

RESULTS

Of tested individuals, 32.0% had antibodies against HHV8 in Sassari and 30.0% in Cagliari. Estimated IR of KS among HHV8-positive persons and KS:HHV8 ratio were two times higher in Sassari (1:3,891) than in Cagliari (1:8,114), and higher in men (1:2,846 in Sassari; 1:5,483 in Cagliari) as compared to women (1:6,827 in Sassari; 1:12,489 in Cagliari).

CONCLUSIONS

Although the overall prevalence of HHV8 seemed similar in Sassari and in Cagliari, the risk of KS was higher in Sassari, suggesting that different cofactor(s), or different distribution of the same cofactor(s) between the two provinces of Sardinia, might have played a role in KS development.

Prevalence of human herpesvirus (HHV)-8 infection among carriers of cardiovascular disease

Infectious agents, such as herpesviruses, have been hypothesized to be involved in development of atheromatous plaque. The study aim was to evaluate the possibility that HHV-8 infection could be an additional risk factor for the establishment of cardiovascular disease. HHV-8 seroprevalence was determined by immunofluorescence in a population of cardiovascular disease patients (n=50) as compared to an age- and sex-matched group of control subjects (n=47); HHV-8 genome was detected in DNA extracted from circulating PBMC and from atheromatous lesions by PCR with primers specific for the minor virus capsid gene (ORF 26). The seroprevalence of HHV-8 was significantly increased in the patients as compared to the control population, while the presence of HHV-8 genome was observed in PBMC from 2 patients and 1 control. Virus-specific DNA was found in 2 out of 4 atheromatous plaques. The higher seroprevalence in patients suffering from vascular diseases as compared to age-and sex-matched controls suggests that HHV-8 infection could be an additional risk factor for the establishment of cardiovascular disease, although the data on the persistence of viral DNA in PBMC or in the arterial lesions are too exiguous to definitively support this hypothesis. More extensive studies are needed to define the exact role of HHV-8 infection in the establishment and progression of atheromatous lesions.

Further evidence against the implication of active cytomegalovirus infection in vascular atherosclerotic diseases

The possible contribution of cytomegalovirus (CMV) to pathogenetic events associated with atherosclerotic lesion establishment and progression is still controversial. We evaluated the possibility that active ongoing CMV infection could be correlated to evolution of unstable atheromatous lesion, by analyzing patients suffering from unstable angina (n=61), acute myocardial infarction (n=43), stable angina (n=26) and peripheral arteriopathy (n=22) as compared to healthy subjects (n=30). Particularly, we assessed: past exposure to CMV by evaluating anti-CMV IgG antibodies; ongoing CMV infection by evaluating anti-CMV IgM antibodies and circulating interleukin (IL)-8 in serum; and CMV DNAemia in peripheral blood mononuclear cells (PBMC). Mean IgG values were significantly increased in patients from all groups, as compared to healthy subjects. CMV-specific IgM, as well as CMV DNAemia, were undetectable in both controls and patients. Circulating IL-8, significantly elevated in a group of individuals experiencing active CMV infection, was not significantly higher in cardiovascular disease patients, as compared to control subjects. These findings confirm previous evidence from the increased exposure to CMV infection in patients with atheromatous lesions. However, they provide further evidence against a direct implication of active systemic CMV infection in the pathogenesis of cardiovascular diseases, particularly those involving plaque instability.

RANTES stimulates cell-mediated transmission of HIV-1 infection

We wished to determine the effects of the beta-chemokine RANTES in an established system of cell-mediated transmission of HIV-1, that is, normal human umbilical vein endothelial cells (HUVEC) nonproductively infected with HIV-1, cocultivated with CD4+ T cells to rescue productive infection. The results indicate that the addition of RANTES to HUVEC, either before or after HIV-1 infection, stimulates HIV-1 rescue by CD4+ T cells. However, viral DNA is not increased in HUVEC, suggesting that the stimulation exerted by RANTES could be mediated by events following HUVEC infection. The mechanisms of increase seem to be related to the rescue phase, involving membrane interaction of abortively infected HUVEC with permissive T cells. In fact, a strong upregulation and polarization of intercellular adhesion molecule-1 (ICAM-1) is induced in HUVEC by RANTES, and antibodies against ICAM-1 inhibit HIV-1 rescue by T cells. These results indicate that RANTES, similarly to other inflammatory cytokines, may favor HIV-1 spreading and crossing of blood-tissue barriers by indirect mechanisms involving membrane interactions between nonproductively infected and permissive cells.

[Age-related changes in the renin-angiotensin-aldosterone system and the sympathetic nervous system in patients with essential hypertension]

The aim of this study was to evaluate age, plasmatic renin activity (PRA), plasma aldosterone levels and the total quantity of urinary catecholamines (TOT. UR. CAT.) in a large population of out-patients suffering from essential arterial hypertension (EAH). A total of 986 patients were examined (540 women and 426 men aged between 15 and 87 years) suffering form slight or moderate EAH (WHO stage 1-2). After a wash-out period of two weeks, systolic and diastolic arterial pressure was measured together with heart rate in clino- and orthostatism. Blood samples were collected to determine PRA and plasma aldosterone, and lastly a 24-hour urine collection was made to measure the total quantity of catecholamines. It emerged that there was a significant increase in systolic pressure, whereas heart rate and PRA diminished significantly when correlated with age; diastolic pressure was also considerably lower, but did not reach statistical significance. Moreover, it was found that there was a significant positive correlation between PRA and TOT. UR. CAT., whereas no correlation was found between age and plasma aldosterone and between blood pressure and the various endocrine parameters examined. These data confirm the changes in the biological, hemodynamic and endocrine profiles observed in elderly hypertensive patients in comparison to young hypertensive patients, and suggests that age may be an important predictive factor of the activity of both the renin-angiotensin and sympathetic nervous system which appear to be closely connected and gradually attenuated by age.

[Role of aldosterone in essential arterial hypertension complicated by chronic renal insufficiency]

The following parameters were studied in a group of patients suffering from essential arterial hypertension complicated by chronic renal insufficiency (CRI), mean age = 64.31 +/- 1.84, with creatinine clearance (CrC) ranging between 30 and 60 ml/min: blood pressure (systolic and diastolic arterial pressure), heart rate, plasmatic renin activity (PRA), plasma levels of aldosterone (ALDO) both in clino- and orthostatism, as well as some metabolic parameters. All parameters were compared with those in a group of age- and sex-matched patients with slight or moderate essential arterial hypertension. Before starting the study all patients completed a wash-out period of one week to annual the effects of other drugs which might interfere with the RAA system. PRA levels were within the norm, whereas plasma levels of ALDO were high both in clino- and orthostatism. ALDO levels were also found to be inversely correlated with those of CrC. From these data it emerges that hyperaldosteronism, as observed in these patients with CRI, is a relatively reliable marker of the extent of CRI and may occur independently of the activation of the RAA system, given that other factors, such as orthostatic stimulation, alterations in the acid-base equilibrium, and the degree of aldosterone hepatic and urinary clearance, contribute to its pathogenesis.

[Incidence of the most frequent complications in hypertensive patients]

The incidence of district (cardiac, cerebral, renal) and systemic vascular complications was studied in a population of 3992 hypertensive in-patients during the period from 1984 to 1988. The total number of male hypertensive patients was always higher (2355) than that of female hypertensive patients (1637). From the analysis of results it appears that 11.01% of male hypertensive patients and 15.85% of female hypertensive patients were diagnosed as being affected by uncomplicated essential arterial hypertension, whereas 88.97% of male and 84.12% of female hypertensive patients suffered from arterial hypertension with varying percentages of cardiac, cerebral, renal or systemic-type atheroarteriosclerotic complications. The prevalence of the male sex was particularly evident in the case of cardiac complications. Given the peak incidence of the various types of complications when analysed by decade of age, an earlier incidence of cardiac and renal complications was found in male hypertensive patients which anticipates the complications found in female hypertensive patients by approximately one decade. Lastly, the paper underlines the social importance of essential arterial hypertension and the need to develop efficacious primary and secondary prevention in order to reduce the incidence of complications which today represent the most severe aspect of hypertension.