Sensorimotor gating deficits in bipolar disorder patients with acute psychotic mania.

Background: Deficits in sensorimotor gating as assessed by prepulse inhibition (PPI) and habituation of the human startle response have been noted in schizophrenia and other patients with known dysfunction in the brain substrates that regulate PPI. During acute mania, bipolar disorder (BD) and schizophrenia patients present with symptoms that are similar. To determine if these clinical similarities extend to neurophysiologic domains, PPI and startle habituation were assessed in BD patients with acute psychotic mania and compared with a sample of acutely psychotic schizophrenia patients and a normal comparison group.

Doppler study of middle cerebral artery blood flow velocity and cerebral autoregulation during a simulated ascent of Mount Everest.

Objective: To explore cerebral hemodynamics in 8 healthy volunteers in a hypobaric chamber up to the altitude of Mount Everest after a progressive stepwise decompression to 8,848 m.

Methods: Physiological, clinical, and transcranial Doppler data were collected after at least 3 days at 5,000, 6,000, and 7,000 m and within 4 hours of reaching 8,000 m and returning to sea level.

Results: Three subjects were excluded at 8,000 and 8,848 m because of acute neurological deficits.

Working memory in schizophrenia: transient "online" storage versus executive functioning.

Working memory has been described as the temporary "online" storage and the subsequent manipulation and retrieval of information. It has been suggested that the prefrontal cortex is a primary site of working memory. Schizophrenia patients, who are thought to have prefrontal cortical dysfunction, have demonstrated inconsistent deficits on a variety of verbal and spatial working memory tests.

Cerebral hemodynamics during arterial and CO(2) pressure changes: in vivo prediction by a mathematical model.

The aim of this work was to analyze changes in cerebral hemodynamics and intracranial pressure (ICP) evoked by mean systemic arterial pressure (SAP) and arterial CO(2) pressure (Pa(CO(2))) challenges in patients with acute brain damage. The study was performed by means of a new simple mathematical model of intracranial hemodynamics, particularly aimed at routine clinical investigation. The model was validated by comparing its results with data from transcranial Doppler velocity in the middle cerebral artery (V(MCA)) and ICP measured in 44 tracings on 13 different patients during mean SAP and Pa(CO(2)) challenges.

Utility of predictive equations for estimating the prevalence and incidence of primary open angle glaucoma in the UK.

Aims: To assess the Tuck-Crick and the Quigley-Vitale predictive regression equations against fresh independent real world data for estimating the prevalence of primary open angle glaucoma (POAG) in the UK. To apply the equations to the elderly population of England and Wales, for which there is sample survey data on glaucoma, and demographic data.

Methods: Directly measured actual prevalence of POAG in a population sample of 1530 people was compared with the predicted prevalence derived by applying the Tuck-Crick and the Quigley-Vitale equations to the sample data.

[Monitoring of severely head-injured patients during the first 24 hours].

Monitoring of severely head-injured patients is essential to optimize cerebral haemodynamics and thus to limit intracranial hypertension and to prevent the occurrence of secondary systemic cerebral injuries. It includes continuous measurement of intracranial pressure, mean arterial pressure and venous jugular oxygen saturation. Assessment of circulatory velocity in the arteries of the polygon of Willis allows identification of intracranial hypertension, and later, a vasospasm in case of subarachnoid haemorrhage.

The deficit in cataract surgery in England and Wales and the escalating problem of visual impairment: epidemiological modelling of the population dynamics of cataract.

Background: The pool of old cases of cataract, the expected new cases, and the shortfall in cataract surgery and consequently the numbers dying with poor vision without the benefit of cataract surgery are regarded as escalating problems worldwide. Successive governments and the professional ophthalmic bodies have not had the wherewithal to estimate the magnitude or interaction of these elements in the population of the UK. This study has collected and applied the best available epidemiological data on cataract prevalence, incidence and service utilisation, and demography to address the problem of control of the cataract pool in the population of England and Wales.

Correlation between cerebral oxygen saturation measured by near-infrared spectroscopy and jugular oxygen saturation in patients with severe closed head injury.

Unlabelled: Near-infrared spectroscopy has been used to monitor cerebral oxygen saturation during cerebral circulatory arrest and carotid clamping. However, its utility has not been demonstrated in more complex situations, such as in patients with head injuries. The authors tested this method during conditions that may alter the arteriovenous partition of cerebral blood in different ways.

Measurement of the charge properties of articular cartilage by an electrokinetic method.

The charge structure of the surface of articular cartilage determines its interactions with the macromolecules and cells of synovial fluid. It may thereby be important to the physiological function and pathological degeneration of the tissue. To determine whether the electrokinetic properties of the surface differ from those of the bulk tissue, we measured the streaming potential generated by the flow of electrolyte over the surface of a cartilage plug mounted in a chamber built for that purpose.

Modeling cerebral autoregulation and CO2 reactivity in patients with severe head injury.

The mathematical model presented in a previous work is used to simulate the time pattern of intracranial pressure (ICP) and of blood velocity in the middle cerebral artery (VMCA) in response to maneuvers simultaneously affecting mean systemic arterial pressure (SAP) and end-tidal CO2 pressure. In the first stage of this study, a sensitivity analysis was performed to clarify the role of some important model parameters [cerebrospinal fluid (CSF) outflow resistance, intracranial elastance coefficient, autoregulation gain, and the position of the regulation curve] during CO2 alteration maneuvers performed at different SAP levels. The results suggest that the dynamic "ICP-VMCA" relationship obtained during changes in CO2 pressure may contain important information on the main factors affecting intracranial dynamics.

Changes in cerebral blood flow during PaCO2 variations in patients with severe closed head injury: comparison between the Fick and transcranial Doppler methods.

Object: The aim of this study was to reassess whether middle cerebral artery blood flow velocity (MCAv) variations measured by transcranial Doppler ultrasonography during acute PaCO2 manipulation adequately reflect cerebral blood flow (CBF) changes in patients with severe closed head injury.

Methods: The study was performed by comparing MCAv variations to changes in CBF as assessed by measurements of the difference in the arteriovenous content in oxygen (AVDO2). The authors initiated 35 CO2 challenges in 12 patients with severe closed head injury during the acute stage.

Refocusing neutralizing antibody response by targeted dampening of an immunodominant epitope.

Immunodominant epitopes are known to suppress a primary immune response to other antigenic determinants by a number of mechanisms. Many pathogens have used this strategy to subvert the immune response and may be a mechanism responsible for limited vaccine efficacies. HIV-1 vaccine efficacy appears to be complicated similarly by a limited, immunodominant, isolate-restricted immune response generally directed toward determinants in the third variable domain (V3) of the major envelope glycoprotein, gp120.

Self-starting Ti:sapphire holographic laser oscillator.

We demonstrate, for the first time to our knowledge, operation of a holographic laser oscillator that uses laser-pumped Ti:sapphire (Ti(3+) : Al(2)O(3)) as the gain medium. The device is self-starting and self-adaptive by virtue of spontaneous gain-grating formation. We present experimental results of the system that include gain-switched pulses of 25-60-ns duration in a TEM(00) mode and as much as 11 mJ of output energy from a plane output coupler and 47 mJ from an intracavity polarizer port.

Familial incidence of late ventricular potentials and electrocardiographic abnormalities in arrhythmogenic right ventricular dysplasia.

Familial forms of arrhythmogenic right ventricular dysplasia (ARVD) have been described. Signal-averaged electrocardiograms (SAECGs) and standard electrocardiograms have been used to detect ARVD. The purpose of this prospective study, for a given family member, was to evaluate the risk of having ARVD or only belonging to an affected family.

Changes in cerebral hemodynamics after a single dose of clonidine in severely head-injured patients.

alpha 2-Adrenergic agonists induce cerebral vasoconstriction, reduce intracranial pressure (ICP) in experimental animals and may be useful in the hemodynamic management of head-injured patients. We studied the effects of the alpha 2 agonist clonidine on the cerebral circulation in 12 head-injured patients (Glasgow Coma Scale score < 8). Middle cerebral artery flow velocity (MCAV), ICP, mean arterial pressure (MAP), and cerebral perfusion pressure (CPP), were continuously recorded before (T0), at the end (T1), and 30 min after (T2) a 10-min intravenous (i.

Selective expansion of specific T cell receptors in the inflamed colon of Crohn's disease.

To identify disease-specific T cell changes that occur in Crohn's disease (CD), the T cell receptor BV repertoires of lamina propria lymphocytes (LPL) isolated from both the inflamed and "disease-inactive" colons of seven CD patients were compared by the quantitative PCR and DNA sequence analysis. It was observed that the BV repertoires of LPL isolated from the disease-active and disease-inactive parts of the colon from the same individual were very different. Furthermore, nearly all of the differences occurred in CD4+ LPL, with very few differences in the CD8+ population of LPL.

CD4+ cell oligoclonality in Crohn's disease: evidence for an antigen-specific response.

To identify disease-specific T cell changes that occur in Crohn's disease (CD) the T-cell receptor (TCR) BV repertoires of lamina propria lymphocytes (LPL) from both disease-active and disease-inactive colonic tissue of three CD patients were compared by a quantitative polymerase chain reaction (qPCR) and CDR3 length analysis. It was observed that the BV repertoires of LPL isolated from the disease-active and disease-inactive parts of the colon of the same individual were different, and most of the differences occurred in CD4+ LPL with very few differences in the CD8+ populations of LPL. Although the pattern of BV segments that was increased in disease-active relative to disease-inactive tissue was different for all three CD patients, there was an increase in the levels of BV11, 13S2, 15, 16, and 17 segments in the disease-active tissue of all three patients.

Amphetamine on Rorschach measures in normal subjects.

Twenty-two normal undergraduate men were administered either d-amphetamine (0.2 mg/kg or 0.4 mg/kg) or placebo in a double-blind, counterbalanced design.

[Cardiovascular effects of a calcium channel blocker in hypoxia caused by altitude].

Objective: High altitude pulmonary oedema can be successfully treated and prevented by calcium channel blockers. Moreover, calcium entering in the cells could explain the congestive phenomena of acute mountain sickness (AMS). These findings led us to study the action of a calcium channel blocker, isradipine, in the prevention of non-complicated AMS.

Construction of an HIV-1 peptide vaccine containing a multideterminant helper peptide linked to a V3 loop peptide 18 inducing strong neutralizing antibody responses in mice of multiple MHC haplotypes after two immunizations.

Peptide constructs comprised of multideterminant Th peptides from the envelope glycoprotein of HIV previously identified to induce proliferative responses in four different haplotypes of mice and IL-2 responses in 52 to 73% of HIV positive, Ag-responsive patients, were colinearly synthesized with the peptide 18 of the V3 loop of HIV-1 gp 160, corresponding to the principal neutralizing determinant of HIV-IIIB. The segments containing clusters of overlapping Th epitopes were called cluster peptides. Cognate help for peptide 18 antibody was elicited after a single immunization in all strains of mice that had previously responded to a T cell epitope encompassed by the cluster peptides.

Cellular localization of simian immunodeficiency virus in lymphoid tissues. I. Immunohistochemistry and electron microscopy.

Simian immunodeficiency virus (SIV) is a lentivirus with genetic relatedness to the human immunodeficiency viruses (HIV-1 and HIV-2). It induces a fatal syndrome in rhesus monkeys that closely parallels the clinical course of AIDS in humans. The authors used double-labeling immunohistochemical procedures on rhesus lymph node and spleen taken during different time periods after SIV infection to localize the p27 gag protein to specific cellular immunophenotypes.

Monoclonal antibodies against human immunodeficiency virus (HIV) type 2 core proteins: cross-reactivity with HIV type 1 and simian immunodeficiency virus.

Four mouse monoclonal antibodies were developed after immunization with one human immunodeficiency virus (HIV) type 2 isolate and were tested for reactivity with different HIV-1, HIV-2, and simian immunodeficiency virus (SIV) isolates in an immunofluorescence assay and by immunological blot analysis. One of them, an anti-capsid (p24) antibody, called R1C7, reacted with all HIV-1, HIV-2, and SIV isolates tested, thus identifying an epitope shared by all HIV and SIV. Another anti-capsid antibody, named A4F6, reacted with three HIV-2 isolates (HIV-2NIH-Z, LAV-2Rod, and LK001 ST9), some SIV isolates (STLV-IIIAGM, SIV-251, and SIV-309), but no HIV-1 isolates.