Frequency, severity and duration of immune reconstitution events in HIV-related tuberculosis

SETTING

Patients were enrolled in a prospective trial of rifabutin-based tuberculosis (TB) treatment for human immunodeficiency virus related TB. Antiretroviral therapy (ART) was encouraged, but not required.

OBJECTIVE

To evaluate the frequency, risk factors and duration of immune reconstitution events.

DESIGN

Patients were prospectively evaluated for immune reconstitution events, and all adverse event reports were reviewed to identify possible unrecognized events.

RESULTS

Of 169 patients, 25 (15%) developed immune reconstitution events related to TB. All 25 were among the 137 patients who received ART during TB treatment, so the frequency in this subgroup was 18% (25/137). Risk factors for an immune reconstitution event in multivariate analysis were Black race, the presence of extra-pulmonary TB and a shorter interval from initiation of TB treatment to initiation of ART. The most common clinical manifestations were fever (64%), new or worsening adenopathy (52%) and worsening pulmonary infiltrates (40%). Twelve patients (48%) were hospitalized for a median of 7 days, six underwent surgery and 11 had needle aspiration. The median duration of events was 60 days (range 11-442).

CONCLUSION

Immune reconstitution events were common among patients receiving ART during TB treatment, produced substantial morbidity and had a median duration of 2 months.

Quality control for microarray analysis of human brain samples: The impact of postmortem factors, RNA characteristics, and histopathology

The quality of results from microarray studies depends on RNA quality, which can be significantly influenced by postmortem factors. The aim of this study was to determine which postmortem factors and/or RNA electropherogram characteristics best correspond to microarray output and can be used to prospectively screen RNA prior to microarray analysis. Total RNA was extracted (N=125) from gray and white matter of postmortem frontal and occipital lobe tissue, acquired from normal controls, and patients with schizophrenia, bipolar disorder or major depression. Electropherograms were generated by the Agilent BioAnalyzer 2100, allowing calculation of the 28S/18S ratio, the 18S/baseline peak ratio and the RNA Integrity Number (RIN). These values were compared to post-hybridization image analysis of Affymetrix microarrays. The postmortem variables correlated with some quality measures but could not be used as effective screening tools. Logistic regression demonstrated that all three electropherogram measures were predictive for microarray quality, and that the RIN threshold predictive of "good quality" (>35% present calls) was most consistent with that of prior studies. The optimal RIN must be determined by the investigator's specifications for false inclusion and false exclusion. In contrast to RIN, the quality threshold for the 28S/18S ratio has proven unacceptably variable, due to sensitivity to slight differences in protocol and/or tissue source. In conclusion, the measures we found useful as screening criteria do not replace the need to exclude samples after a microarray analysis is performed, as an acceptable percent call rate and other measures of microarray quality represent the desired endpoint.

NK Cells Lyse T Regulatory Cells in Human Infection with An Intracellular Pathogen (B167)

Previously we found that regulatory T cells (CD4+CD25+Foxp3+ cells, Tregs) expand in response to M.tuberculosis (M. TB) through mechanism that depend on prostaglandin E2 production. In the current study, we determined the role of NK cells in regulating Tregs expansion in human M. TB infection. M. TB whole cell lysate (TB lysate) resulted in regulatory T cell expansion (15.33±1.02% vs 1.5±0.22%, P<0.001). Addition of monokine-activated NK cells (IL-12, IL-15 and IL-18) markedly inhibited Treg expansion (6.2±1.2% vs 15±1.5%, P<0.001) but freshly isolated NK cells had no effect. NK cells activated with TB lysate-stimulated monocytes also reduced Tregs expansion (13.2±0.3% to 3.4±1.4%, P<0.001) confirming the physiological relevance of this effect. Reduced Tregs expansion was not due to inhibition of PGE2 production or because of IFN γ. Monokine activated NK cells lysed TB lysate-expanded Tregs, but not freashly isolated Tregs (% specific lysis of 21±3% vs 1±1% P<0.001), nor T regs depleted T cells. Anti-NKG2D and anti-NKp46 reduced the % specific lysis of expanded Tregs from 22±3% to 7±3% and 8±3%, respectively (P<0.001) but abs to CD16, DNAM-1, and 2B4 had no effect. NKG2D ligand, ULBP1 expression was markedly upregulated on expanded T regs, compared to T regs depleted cells ( 31±5% vs 2.1 ±0.4%, P=0.002) and freshly isolated Tregs (4.6±1.1%). Anti -ULBP1 significantly inhibited the NK mediated lysis of expanded Tregs (specific lysis of 27±4% vs 9±2%, P<0.001) but abs to ULBP2, ULBP3 and MICA/B had no effect. These finding suggest that NK cells reduce the frequency of M.TB-expanded T regs by direct lysis.

Expression of CB1 cannabinoid receptor in the anterior cingulate cortex in schizophrenia, bipolar disorder, and major depression

The human endogenous cannabinoid system is an appealing target in the investigation of psychiatric disorders. In schizophrenia, endocannabinoids and their receptors are involved in the pathology of the disease. Previous studies reported an increased radioligand binding to cannabinoid receptors 1 (CB(1)) in schizophrenia, both in the dorsolateral prefrontal cortex and in the anterior cingulate cortex (ACC). We analyzed the expression of the CB(1) receptors in the ACC at the protein level using immunohistochemistry. In a quantitative postmortem study, 60 patients suffering from schizophrenia, bipolar disorder, major depression and controls were included. Numerical densities of neurons and glial cells immunopositive for CB(1) receptors were evaluated. No evidence of an increased or decreased density of CB(1) receptor immunopositive cells in schizophrenia or bipolar disorder was found. In major depression, CB(1) receptor immunopositive glial cells in the grey matter were decreased. Furthermore, our data show that different medications have an impact on the expression of CB(1) receptors in the ACC.

Reduced expression of human endogenous retrovirus (HERV)-W GAG protein in the cingulate gyrus and hippocampus in schizophrenia, bipolar disorder, and depression

The human endogenous retrovirus (HERV)-W multicopy family was identified in human DNA from the previously characterized multiple sclerosis associated retroviral element (MSRV). Upregulation of the HERV-W POL has been reported in cerebrospinal fluid of patients with schizophrenia. The expression of capsid (GAG) protein of HERV-W was studied by immunohistochemistry and western blotting in postmortem brain tissue of the anterior cingulate cortex and hippocampal formation of normal controls and of patients with schizophrenia, bipolar disorder and major depression. A physiological expression of GAG protein was detected in neurons as well as astroglial cells in normal brain both in the anterior cingulate cortex and in the hippocampal formation. There was a statistically significant reduction of this expression in neurons and astroglial cells in brains from individuals with schizophrenia, major depression, and bipolar disorder. The results from the present study confirm that GAG protein encoded by the HERV-W multicopy gene family is expressed in cells of the central nervous system under normal conditions. Our findings of a cell type-, brain region- and disease-specific reduced expression in schizophrenia, major depression, and bipolar disorder are compatible with a pathophysiological role of HERVs in human brain disorders. The causes and biological consequences of this differential regulation will be the subject of further investigations.

Cotrimoxazole-induced psychosis: a case report and review of literature

We present a case of acute psychosis in a 46-year-old woman who had been treated orally with cotrimoxazole because of a severe infection of the urinary tract. She had started to develop psychotic symptoms with bizarre behavior two days before admission. Following discontinuation of antibiotic therapy, including cessation of treatment with cotrimoxazole and the induction of antipsychotic treatment, her mental state resolved to a stable premorbid level within 36 hours.

Quantification of total mitochondrial DNA and mitochondrial common deletion in the frontal cortex of patients with schizophrenia and bipolar disorder

Data published during the last decade are suggestive of a role for mitochondrial dysfunction in the pathogenesis of schizophrenia, bipolar disorder and other psychiatric diseases. In order to determine if the mitochondrial deficits reported in the literature are caused by abnormalities in the mitochondrial DNA of psychiatric patients, we quantified mitochondrial DNA (mtDNA) levels and the 5 kb common mitochondrial deletion (CD) in postmortem frontal cortex tissue. The mitochondrial CD and mtDNA levels were measured in tissue obtained from the frontal cortex (Brodmann Area 46) of 144 individuals (45 patients with schizophrenia, 40 patients with bipolar disorder, 44 controls, and 15 patients with major depression). These variables were measured using newly developed SYBR green and TaqMan real time PCR assays. Both the TaqMan and the SYBR green assays gave similar results. There was no statistically significant difference for the quantity of the common mitochondrial deletion between controls and patients. We also did not detect a difference in the mtDNA levels amongst the diagnosis groups. There were statistically significant differences for the evaluated parameters for smokers, schizophrenic patients on antipsychotic drugs at time of death, and bipolar patients with antidepressant use and alcohol abuse. Based on this study and other reports, we conclude that neither the common mitochondrial deletion nor changes in mitochondrial DNA levels are likely to account for the mitochondrial changes associated with bipolar disorder or schizophrenia. The effect of premortem agonal factors and medication on mitochondrial dysfunction still needs further elucidation.

Phosphoinositide 3-kinase gamma/delta inhibition limits infarct size after myocardial ischemia/reperfusion injury

Although phosphoinositide 3-kinases (PI3Ks) play beneficial pro-cell survival roles during tissue ischemia, some isoforms (gamma and delta) paradoxically contribute to the inflammation that damages these same tissues upon reperfusion. We therefore considered the possibility that selectively inhibiting proinflammatory PI3K isoforms during the reperfusion phase could ultimately limit overall tissue damage seen in ischemia/reperfusion injuries such as myocardial infarction. Panreactive and isoform-restricted PI3K inhibitors were identified by screening a novel chemical family; molecular modeling studies attributed isoform specificity based on rotational freedom of substituent groups. One compound (TG100-115) identified as a selective PI3K gamma/delta inhibitor potently inhibited edema and inflammation in response to multiple mediators known to participate in myocardial infarction, including vascular endothelial growth factor and platelet-activating factor; by contrast, endothelial cell mitogenesis, a repair process important to tissue survival after ischemic damage, was not disrupted. In rigorous animal MI models, TG100-115 provided potent cardioprotection, reducing infarct development and preserving myocardial function. Importantly, this was achieved when dosing well after myocardial reperfusion (up to 3 h after), the same time period when patients are most accessible for therapeutic intervention. In conclusion, by targeting pathologic events occurring relatively late in myocardial damage, we have identified a potential means of addressing an elusive clinical goal: meaningful cardioprotection in the postreperfusion time period.

The effect of word concreteness on recognition memory

Concrete words that are readily imagined are better remembered than abstract words. Theoretical explanations for this effect either claim a dual coding of concrete words in the form of both a verbal and a sensory code (dual-coding theory), or a more accessible semantic network for concrete words than for abstract words (context-availability theory). However, the neural mechanisms of improved memory for concrete versus abstract words are poorly understood. Here, we investigated the processing of concrete and abstract words during encoding and retrieval in a recognition memory task using event-related functional magnetic resonance imaging (fMRI). As predicted, memory performance was significantly better for concrete words than for abstract words. Abstract words elicited stronger activations of the left inferior frontal cortex both during encoding and recognition than did concrete words. Stronger activation of this area was also associated with successful encoding for both abstract and concrete words. Concrete words elicited stronger activations bilaterally in the posterior inferior parietal lobe during recognition. The left parietal activation was associated with correct identification of old stimuli. The anterior precuneus, left cerebellar hemisphere and the posterior and anterior cingulate cortex showed activations both for successful recognition of concrete words and for online processing of concrete words during encoding. Additionally, we observed a correlation across subjects between brain activity in the left anterior fusiform gyrus and hippocampus during recognition of learned words and the strength of the concreteness effect. These findings support the idea of specific brain processes for concrete words, which are reactivated during successful recognition.

Changes in region- and cell type-specific expression patterns of neutral amino acid transporter 1 (ASCT-1) in the anterior cingulate cortex and hippocampus in schizophrenia, bipolar disorder and major depression

Although, the pathogenetic mechanisms of schizophrenia, bipolar disorder, and major depression are not clearly understood, various neurotransmitter systems are reported to have altered expression patterns of their receptor and transporter proteins. Changes in the expression of the neutral amino acid transporter 1 (ASCT-1) protein in the anterior cingulate gyrus and the hippocampus were investigated using immunohistochemistry and western blotting. A significant decrease in ASCT-1 immunoreactivity in neurons in the cingulate cortex as well as astrocytes of the white matter was seen in schizophrenia. In bipolar disorder and major depression, similar results were seen for neurons. In the hippocampus, there was a striking loss of immunoreactivity on astrocytes, neurons and interneurons in multiple regions in schizophrenia and bipolar disorder, while only minor changes were seen in major depression. The altered expression of ASCT-1 in neurons and astrocytes reflects profound changes in glutamatergic neurotransmission and highlights a significant role of astrocytes in the pathophysiology of neurotransmission in these major psychiatric disorders.

Spatial attention: more than intrinsic alerting?

It has been proposed that the right hemisphere alerting network co-activates, either directly or via the brainstem, the attention system in the parietal cortex involved in spatial attention. The observation that impaired alertness and sustained attention can predict the outcome of neglect might suggest such a relationship, too. In the present fMRI study, we intended to analyse and compare the functional anatomy of two attentional conditions both involving intrinsic (endogenous) alerting and fixation but differing with respect to the degree of spatially distributed attention by using the same paradigm under two different attentional conditions. In a group of ten participants, both a focused and a distributed visuospatial attention condition evoked similar patterns of activation in dorsolateral prefrontal regions, in the anterior cingulate gyrus, in the superior and inferior parietal cortex as well as in the superior temporal gyrus and in the thalamus. These activation foci were stronger in the right hemisphere under both conditions. After subtraction of the alertness condition with focused spatial attention, distributed spatial attention with stimuli appearing at unpredictable locations within both visual fields induced additional bilateral activations only in the left and right superior parietal cortex and in the right precuneus suggesting that these regions are specific for a more widespread dispersion of spatial attention.

Endothelial barrier disruption by VEGF-mediated Src activity potentiates tumor cell extravasation and metastasis

VEGF is unique among angiogenic growth factors because it disrupts endothelial barrier function. Therefore, we considered whether this property of VEGF might contribute to tumor cell extravasation and metastasis. To test this, mice lacking the Src family kinases Src or Yes, which maintain endothelial barrier function in the presence of VEGF, were injected intravenously with VEGF-expressing tumor cells. We found a dramatic reduction in tumor cell extravasation in lungs or livers of mice lacking Src or Yes. At the molecular level, VEGF compromises the endothelial barrier by disrupting a VE-cadherin–β-catenin complex in lung endothelium from wild-type, but not Yes-deficient, mice. Disrupting the endothelial barrier directly with anti–VE-cadherin both amplifies metastasis in normal mice and overcomes the genetic resistance in Yes-deficient mice. Pharmacological blockade of VEGF, VEGFR-2, or Src stabilizes endothelial barrier function and suppresses tumor cell extravasation in vivo. Therefore, disrupting Src signaling preserves host endothelial barrier function providing a novel host-targeted approach to control metastatic disease.

Src blockade stabilizes a Flk/cadherin complex, reducing edema and tissue injury following myocardial infarction

Ischemia resulting from myocardial infarction (MI) promotes VEGF expression, leading to vascular permeability (VP) and edema, a process that we show here contributes to tissue injury throughout the ventricle. This permeability/edema can be assessed noninvasively by MRI and can be observed at the ultrastructural level as gaps between adjacent endothelial cells. Many of these gaps contain activated platelets adhering to exposed basement membrane, reducing vessel patency. Following MI, genetic or pharmacological blockade of Src preserves endothelial cell barrier function, suppressing VP and infarct volume, providing long-term improvement in cardiac function, fibrosis, and survival. To our surprise, an intravascular injection of VEGF into healthy animals, but not those deficient in Src, induced similar endothelial gaps, VP, platelet plugs, and some myocyte damage. Mechanistically, we show that quiescent blood vessels contain a complex involving Flk, VE-cadherin, and beta-catenin that is transiently disrupted by VEGF injection. Blockade of Src prevents disassociation of this complex with the same kinetics with which it prevents VEGF-mediated VP/edema. These findings define a molecular mechanism to account for the Src requirement in VEGF-mediated permeability and provide a basis for Src inhibition as a therapeutic option for patients with acute MI.

Intrasubject reproducibility of presurgical language lateralization and mapping using fMRI

BACKGROUND

fMRI is becoming a standard tool for the presurgical lateralization and mapping of brain areas involved in language processing. However, its within-subject reproducibility has yet to be fully explored.

OBJECTIVE

To evaluate within-test and test-retest reliability of language fMRI in consecutive patients undergoing evaluation for epilepsy surgery.

METHODS

Thirty-four unselected patients were investigated once (within-test reliability) and 12 patients twice (test-retest reliability). The imaging series consisted of an alternating 25-second synonym judgment condition with a 25-second letter-matching condition repeated 15 times. Reproducibility of activation maps of the first and second half of session 1 or activation maps of sessions 1 and 2 was evaluated by comparing one global and three regional lateralization indexes (Broca's area, remaining prefrontal cortex, temporoparietal area) and on a voxel-by-voxel basis (intraclass correlation coefficient, percentage overlap, correlation of t-values).

RESULTS

Global and regional language lateralization was achieved with high reliability within and across sessions. Reproducibility was evenly distributed across both hemispheres but not within each hemisphere. Frontal activations were more reliable than temporoparietal ones. Depending on the statistical threshold chosen, the voxel-by-voxel analysis revealed a mean overlap of activations derived from the first and second investigation of up to 48.9%.

CONCLUSION

Language fMRI proved sufficiently reliable for the determination of global and regional lateralization of language representation in individual unselected patients with epilepsy.

Comparison between mitochondrial DNA sequences in low grade astrocytomas and corresponding blood samples

BACKGROUND/AIMS

To identify somatic mutations in the mitochondrial DNA of glioblastomas, in a previous study the displacement loops of 17 glioblastomas and corresponding blood samples were sequenced and instabilities in repeats or transitions were detected in seven tumours. This study was extended by sequencing 10 DNA samples of diffuse astrocytomas (World Health Organisation grade II) and corresponding blood samples.

METHODS

The 10 DNA samples of diffuse astrocytomas and corresponding blood samples were amplified and sequenced using fluorescent nucleotides.

RESULTS

No sequence differences were detected, with the exception of a quantitative shift between two genotypes heteroplasmic within the hypervariable region 2, which can be interpreted as mitotic drift. In the glioblastoma series, any particular somatic mutation was usually found in only one tumour. The only frequent alteration was coupled to a mitochondrial germline polymorphism under-represented in the low grade astrocytoma group. Moreover, a single mutation in two patients with secondary glioblastomas had already been detected in diffuse astrocytomas of these individuals.

CONCLUSIONS

A lower percentage of mitochondrial DNA mutations in low grade tumours cannot be deduced from these data.

Uterine leiomyosarcoma metastatic to the brain stem

A patient with a history of an uterine leiomyosarcoma presented with diplopia, gait disturbances, and hypesthesia of the right face. MRI of the head showed a lesion located in the pons and causing obstructive hydrocephalus. Open biopsy revealed a metastatic tumor with histological features of leiomyosarcoma. Despite whole-brain irradiation, the patient died due to respiratory arrest. This case illustrates that brain stem metastasis may occur as a rare complication in uterine leiomyosarcoma.