Streamlining SARS-CoV-2 confirmatory testing to reduce false positive results

BACKGROUND

Confirmatory testing of SARS-CoV-2 results is essential to reduce false positives, but comes at a cost of significant extra workload for laboratories and increased turnaround time. A balance must be sought. We analysed our confirmatory testing pathway to produce a more refined approach in preparation for rising case numbers.

METHODS

Over a 10-week low prevalence period we performed confirmatory testing on all newly positive results. Turnaround time was measured and results were analysed to identify a threshold that could be applied as a cut-off for future confirmatory testing and reduce overall workload for the laboratory.

RESULTS

Between 22/06/20 and 31/08/20 confirmatory testing was performed on 108 newly positive samples, identifying 32 false positive results (30 %). Turnaround time doubled, increasing by an extra 17 h. There was a highly statistically significant difference between initial Relative Light Unit (RLU) of results that confirmed compared to those that did not, 1176 vs 721 (P < 0.00001). RLU = 1000 was identified as a suitable threshold for confirmatory testing in our laboratory: with RLU ≥ 1000, 55/56 (98 %) confirmed as positive, whereas with RLU < 1000 only 12/38 (32 %) confirmed.

CONCLUSIONS

False positive SARS-CoV-2 tests can be identified by confirmatory testing, yet this may significantly delay results. Establishing a threshold for confirmatory testing streamlines this process to focus only on samples where it is most required. We advise all laboratories to follow a similar process to identify thresholds that trigger confirmatory testing for their own assays, increasing accuracy while maintaining efficiency for when case numbers are high.

Tunicamycin Enhances Neuroinvasion and Encephalitis in Mice Infected with Venezuelan Equine Encephalitis Virus

Venezuelan equine encephalitis (VEE) viruses cause natural outbreaks in humans and horses and represent a significant biothreat agent. The effect of tunicamycin on the course of the disease in mice with VEE was investigated, and the combined effects of these agents was characterized. CD-1 mice given 2.5 μg of tunicamycin had > 1,000-fold more virus in the brain 48 hours after infection with the virulent VEE strain V3000 and >100-fold of the attenuated strain V3034 at all tested times than did untreated mice, indicating enhanced neuroinvasion. Tunicamycin did not alter the viremia profiles of these viruses nor the replication of V3000 in the brain itself. Tunicamycin alone caused ultrastructural blood-brain barrier damage, yet neuroinvasion by V3000 in treated mice appeared to occur via the olfactory system rather than the blood-brain barrier. Tunicamycin-treated, V3000-infected mice also exhibited earlier and more severe weight loss, neurological signs, neuronal infection, neuronal necrosis and apoptosis, and inflammation than untreated, V3000-infected mice. The mean survival time of tunicamycin-treated, V3000-infected mice was 7.3 days versus 9.9 days for untreated, V3000-infected mice. These studies imply that animals that ingest toxins similar to tunicamycin, including the agent of annual ryegrass toxicity in livestock, are conceivably at greater risk from infections by encephalitis viruses and that humans and horses exposed to agents acting similar to tunicamycin may be more susceptible to encephalitis caused by VEE viruses. The exact mechanism of tunicamycin-enhanced neuroinvasion by VEE viruses requires further study.

Effector T cells immune reactivity among patients with acute hepatitis E

Hepatitis E virus (HEV) is a leading cause of acute viral hepatitis in several developing countries. Information on cellular immune responses during acute hepatitis E is limited. We therefore studied peripheral blood mononuclear cells (PBMCs) from patients with acute hepatitis E and healthy adult subjects who lacked anti-HEV antibodies for enumeration of various T-cell subsets using flow cytometry and to assess HEV-specific T effector cell responses using interferon-gamma ELISPOT assays. The patients showed increased numbers of CD8(+) cells and CD4(+) CD8(+) cells compared with healthy controls. In addition, the proportion of PBMCs that produced interferon-gamma in response to recombinant HEV open reading frame (ORF) 2 and ORF 3 proteins were found to be higher in patients than in healthy controls. Using pools of 15-mer overlapping peptides corresponding to these recombinant proteins, the immunodominant regions in these proteins for interferon-gamma-producing cells were mapped to regions corresponding to amino acids 181-249 and 301-489 of HEV ORF2 protein. These data provide evidence for the activation of effector T cells during acute hepatitis E. These responses may play a role in viral clearance from the host in patients with HEV infection.

Indicators of pretreatment suicidal ideation in adults with major depressive disorder

OBJECTIVE

In order to evaluate the presence of treatment emergent suicidal ideation (SI), it becomes necessary to identify those patients with SI at the onset of treatment. The purpose of this report is to identify sociodemographic and clinical features that are associated with SI in major depressive disorder (MDD) patients prior to treatment with a selective serotonin reuptake inhibitor.

METHOD

This multisite study enrolled 265 out-patients with non-psychotic MDD. Sociodemographic and clinical features of participants with and without SI were compared post hoc.

RESULTS

Social phobia, bulimia nervosa, number of past depressive episodes, and race were independently associated with SI by one or more SI measure.

CONCLUSION

Concurrent social phobia and bulimia nervosa may be potential risk factors for SI in patients with non-psychotic MDD. Additionally, patients with more than one past depressive episode may also be at increased risk of SI.

Electroconvulsive therapy is equally effective in unipolar and bipolar depression

OBJECTIVE

To determine the relative efficacy of electroconvulsive therapy (ECT) in the treatment of bipolar (BP) and unipolar (UP) depressive illness and clarify its role in BP depression.

METHOD

Patients referred for ECT with both UP and BP depressions. [classified by Structured Clinical Interview for DSM (SCID-I) criteria for history of mania] were included in a multi-site collaborative, double-masked, randomized controlled trial of three electrode placements - right unilateral, bifrontal or bitemporal - in a permutated block randomization scheme.

RESULTS

Of 220 patients, 170 patients (77.3%) were classified as UP and 50 (22.7%) as BP depression in the intent-to-treat sample. The remission and response rates and numbers of ECT for both groups were equivalent.

CONCLUSION

Both UP and BP depressions remit with ECT. Polarity is not a factor in the response rate. In this sample ECT did not precipitate mania in depressed patients. Treatment algorithms for UP and BP depression warrant re-evaluation.

Painful physical symptoms and treatment outcome in major depressive disorder: a STAR*D (Sequenced Treatment Alternatives to Relieve Depression) report

BACKGROUND

Painful physical symptoms (PPS) are both common and reduce the likelihood of remission in major depressive disorder (MDD), based upon results of clinical trials in selected populations. Whether PPS significantly contribute to poorer treatment outcome overall in primary or specialty psychiatric care settings remains unclear.

METHOD

Out-patients (n=2876) with MDD were treated in the first step of the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial with citalopram up to 60 mg/day for up to 14 weeks. Presence of painful symptoms, as well as severity of depression, physical illness, and demographic and treatment factors were examined. Time to and overall rates of remission were analysed in relation to the presence of PPS.

RESULTS

Of the participants, 80% complained of PPS. These patients, both in primary and specialty psychiatric settings, had significantly lower remission rates and took longer to remit. Increasing severity of PPS was associated with greater physical illness burden, lower socio-economic status, absence of private insurance and being female, African-American or Hispanic. After adjustment for these factors, patients with PPS no longer had significantly poorer treatment outcomes.

CONCLUSIONS

Presence and severity of PPS is an indicator of MDD that may have poorer treatment outcome with an initial selective serotonin reuptake inhibitor. These poorer treatment outcomes are multifactorial, however, and are not explained by the presence and severity of pain per se.

Residual symptoms after remission of major depressive disorder with citalopram and risk of relapse: a STAR*D report

BACKGROUND

Many patients with major depressive disorder (MDD) who experience full symptomatic remission after antidepressant treatment still have residual depressive symptoms. We describe the types and frequency of residual depressive symptoms and their relationship to subsequent depressive relapse after treatment with citalopram in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) trial.

METHOD

Participants in primary (n=18) and psychiatric (n=23) practice settings were openly treated with citalopram using measurement-based care for up to 14 weeks and follow-up for up to 1 year. We assessed 943 (32.8% of 2876) participants who met criteria for remission to determine the proportions with individual residual symptoms and any of the nine DSM-IV criterion symptom domains to define a major depressive episode. At each visit, the 16-item Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR16) and the self-report Frequency, Intensity, and Burden of Side Effects Rating (FIBSER) scale were used to assessed depressive symptoms and side-effects respectively.

RESULTS

More than 90% of remitters had at least one residual depressive symptom (median=3). The most common were weight increase (71.3%) and mid-nocturnal insomnia (54.9%). The most common residual symptom domains were sleep disturbance (71.7%) and appetite/weight disturbance (35.9%). Those who remitted before 6 weeks had fewer residual symptoms at study exit than did later remitters. Residual sleep disturbance did not predict relapse during follow-up. Having a greater number of residual symptom domains was associated with a higher probability of relapse.

CONCLUSIONS

Patients with remission of MDD after treatment with citalopram continue to experience selected residual depressive symptoms, which increase the risk of relapse.

Preadult onset vs. adult onset of major depressive disorder: a replication study

OBJECTIVE

In the first 1500 participants with major depressive disorder (MDD) that entered the sequenced treatment alternatives to relieve depression (STAR*D) study, those with preadult onset MDD were more likely to be women and to have a more chronic, severe and disabling form of depression than those with adult onset MDD. This study seeks to replicate these findings.

METHOD

The second wave of STAR*D enrollees included 2541 out-patients with MDD, divided into preadult (before age 18) and adult (age 18 or later) onset groups.

RESULTS

Participants with a preadult onset of MDD (38%) were younger, ill for longer and more likely to be women than those with adult onset MDD (62%). After adjusting for age, duration of illness and gender, participants with preadult onset MDD also had higher rates of family history of depression, more past suicide attempts, and lower rates of obsessive compulsive and panic disorder.

CONCLUSION

Preadult onset MDD may be associated with a more familial form of depression with more suicidality than adult onset MDD.

Co-infection by Semliki forest virus and malarial parasite modulates viral multipucation, pathogenesis and cytokines in mice

Environmental, technological and societal factors continue to have a dramatic effect on infectious diseases worldwide and are considered to be facilitating the emergence of several infectious diseases at a time. Co-infection with different species of viral and malaria infections are currently emerging problems of dual infection in the developing as well as developed countries. Understanding of interactions between the host, malaria and virus infection is of current concern and we have initiated studies to delineate the mechanisms involved during the progression of Semliki forest virus (SFV) and Plasmodium yoelii (P. yoelii) infection in mice. Enhanced virus multiplication and up-regulation of cytokine mRNA level in P. yoelii and SFV co-infected mice were observed on day 4 post-infection compared to respective controls. Collectively, our observations indicate that malaria infection may influence virus multiplication, pathogenesis and up-regulation of cytokine mRNA during co-infection in mice.

Hydroxyl radical formation resulting from the interaction of nickel complexes of L-histidine, glutathione or L-cysteine and hydrogen peroxide

L-histidine, L-cysteine, reduced glutathione (GSH) and other bioligands, which are ubiquitously present in biological systems, are recognized as antioxidants. Studies have shown that nickel (II) complexed with these ligands catalyzes the disproportionation of H2O2, leading to the generation of hydroxyl radicals (OH radical). However, none of the studies could provide information regarding effective concentrations at which these ligands act either as pro-oxidant or antioxidant. Therefore, the observed paradoxical behaviour of biological antioxidants in nickel-induced oxidative response was evaluated. Benzoic acid (BA) is hydroxylated by OH radical to form highly fluorescent dihydroxy benzoate (OH-BA). We used this model to study the effect of nickel complexes of L-histidine, GSH or L-cysteine on the hydroxylation of BA. The concentration-dependent effect of L-histidine, GSH and L-cysteine, or nickel on the hydroxylation of BA was studied. The hydroxylation of BA was significantly enhanced up to 1:0.5 molar ratio (Ni:hist or GSH). However, beyond 1:0.5 molar ratios, histidine/GSH inhibited the hydroxylation and complete inhibition was observed at 1:1 molar ratios. Sorbitol and caffeic acid, considered as scavengers of hydroxyl radicals, inhibited nickel-induced hydroxylation of BA. The present study demonstrates paradoxical behaviour of these bioligands. They act as pro-oxidant at lower ligand ratios and as antioxidant at higher ligand ratios. The redox properties of nickel complexes with histidine, GSH or cysteine reported here may be crucial for the toxicity of nickel.

Scavenging action of zinc and green tea polyphenol on cisplatin and nickel induced nitric oxide generation and lipid peroxidation in rats

OBJECTIVE

Toxic metal ions have been implicated in the generation of reactive oxygen species (ROS) and nitric oxide (NO). Metallothionines (MT) and plant flavonoids have been reported in the intervention against oxidative damage. We investigated the effect of zinc induced MT and green tea polyphenol (GTP) in reducing the oxidative responses induced by nickel and platinum.

METHODS

Zinc (10 mg/kg b. wt, sc) was administered to rats twice at a gap of 24 hrs and GTP (10 mg/100 mL in drinking water) was fed ad libitum for 8 days. Nickel chloride (150 umol/kgb.wt, ip) and cisplatin (50 mumol/kg b.wt, sc) was administered to rats 24 h after Zn or GTP pre-treatment. Animals of all the groups were sacrificed 16 hrs after treatment and biochemical markers for toxicity were monitored.

RESULTS

Zinc or GTP pre-treatment caused significant protection against nickel or cisplatin enhanced mortality in rats, and reduction in lipid peroxidation and NO.

CONCLUSION

It is proposed that inhibition of ROS and NO by GTP and zinc may prove useful as a selective pharmacological agent in the amelioration of metal toxicity.

Exacerbation of soft tissue lesions in lead exposed virus infected mice

OBJECTIVE

To investigate the effect of Lead (Pb) acetate exposure on Semliki forest virus (SFV) pathogenesis in mice.

METHODS

Different doses (62.5, 125, 250 and 500 mg/Kg body weight) of Pb dissolved in normal saline were given to mice by oral intubation in a sub-acute (28 days) and sub-chronic (90 days) regimen followed by SFV infection. Morbidity, mortality, clinical symptoms, mean survival time (MST), changes in body and organ weight, accumulation of lead in soft tissues, virus titre in brain and histopathological alterations were compared between lead exposed and infected groups.

RESULTS

Early appearance of virus symptoms, increased mortality, decreased MST, enhanced SFV titre and greater tissue damage were observed in lead exposed-SFV-infected mice.

CONCLUSION

Pre-exposure to lead increases the susceptibility of mice towards SFV infection. Further studies are suggested in view of the persistence of lead in the environment and the possibility of infection by microbial pathogens.

Lead exposure enhances virus multiplication and pathogenesis in mice

Suppression of the immune system by environmental xenobiotics may cause increased susceptibility of the host towards a variety of microbial pathogens an result in a life-threatening state. We investigated whether lead exposure would enhance susceptibility to Semliki Forest Virus (SFV). Mice orally exposed to lead acetate (62.5, 125, 250 or 500 mg/kg bw) exhibited increased mortality and decreased mean survival time compared to untreated animals on challenge with SFV. The mortality was associated with enhancement of high virus titer and earlier appearance of virus in lead-exposed mice. Histopathological studies observed enhancement of viral pathogenesis in a dose dependent pattern in the lead-dosed group challenged with SFV. The results indicate that exposure to lead enhanced susceptibility to viral infection. Environmental metal contamination and subsequent infection by pathogenic microbes points necessitate studies on the interaction of environmental pollutants on the immune system.

ECT remission rates in psychotic versus nonpsychotic depressed patients: a report from CORE

OBJECTIVE

To compare the relative efficacy of electroconvulsive therapy (ECT) in psychotic and nonpsychotic patients with unipolar major depression.

METHODS

The outcome of an acute ECT course in 253 patients with nonpsychotic (n = 176) and psychotic (n = 77) unipolar major depression was assessed in the first phase of an ongoing National Institute of Mental Health-supported four-hospital collaborative study of continuation treatments after successful ECT courses. ECT was administered with bilateral electrode placement at 50% above the titrated seizure threshold. The remission criteria were rigorous: a score <or=10 on the 24-item Hamilton Rating Scale for Depression (HRSD) after 2 consecutive treatments, and a decrease of at least 60% from baseline.

RESULTS

The overall remission rate was 87% for study completers. Among these, patients with psychotic depression had a remission rate of 95% and those with nonpsychotic depression, 83%. Improvement in symptomatology, measured by the HRSD, was more robust and appeared sooner in the psychotic patients compared with the nonpsychotic patients.

CONCLUSION

Bilateral ECT is effective in relieving severe major depression. Remission rates are higher and occur earlier in psychotic depressed patients than in nonpsychotic depressed patients. These data support the argument that psychotic depression is a distinguishable nosological entity that warrants separate treatment algorithms.

Vagus nerve stimulation (VNS) for treatment-resistant depression: efficacy, side effects, and predictors of outcome

This open pilot study of vagus nerve stimulation (VNS) in 60 patients with treatment-resistant major depressive episodes (MDEs) aimed to: 1) define the response rate; 2) determine the profile of side effects; and, most importantly; 3) establish predictors of clinical outcome. Participants were outpatients with nonatypical, nonpsychotic, major depressive or bipolar disorder who had not responded to at least two medication trials from different antidepressant classes in the current MDE. While on stable medication regimens, the patients completed a baseline period followed by device implantation. A 2-week, single blind, recovery period (no stimulation) was followed by 10 weeks of VNS. Of 59 completers (one patient improved during the recovery period), the response rate was 30.5% for the primary HRSD(28) measure, 34.0% for the Montgomery-Asberg Depression Rating Scale (MADRAS), and 37.3% for the Clinical Global Impression-Improvement Score (CGI-I of 1 or 2). The most common side effect was voice alteration or hoarseness, 55.0% (33/60), which was generally mild and related to output current intensity. History of treatment resistance was predictive of VNS outcome. Patients who had never received ECT (lifetime) were 3.9 times more likely to respond. Of the 13 patients who had not responded to more than seven adequate antidepressant trials in the current MDE, none responded, compared to 39.1% of the remaining 46 patients (p =.0057). Thus, VNS appears to be most effective in patients with low to moderate, but not extreme, antidepressant resistance. Evidence concerning VNS' long-term therapeutic benefits and tolerability will be critical in determining its role in treatment-resistant depression.

Hippocampal abnormalities in depression

A quantitative magnetic resonance imaging study of regional brain T1 spin-lattice relaxation times in 29 normal volunteers and in 20 patients with major depression revealed significantly shortened T1 relaxation times for the hippocampus in depressed patients. These differences were particularly prominent in elderly depressed patients. T1 relaxation times are reflective of the content and macromolecular environment of tissue water protons; shorter hippocampal T1 values may reflect differences in the content or organizational properties of hippocampal water protons. These findings are consistent with several lines of evidence that have implicated a role for the hippocampus in the regulation of mood and in the pathophysiology of the stress response, and they suggest that major depression may be associated with biophysical tissue changes in the aging hippocampus.

Aging of the human corpus callosum: magnetic resonance imaging in normal volunteers

A brain magnetic resonance imaging (MRI) study of the corpus callosum in 36 normal volunteers, ages 26-79 years, revealed that age was positively correlated with the T1 spin-lattice relaxation time of the corpus callosum and was negatively correlated with the corpus callosum cross-sectional area. T1 relaxation times are sensitive to the content and macromolecular environment of tissue water, and variations in callosal T1 may reflect differences in the content or relaxation properties of callosal water. Such changes also potentially could occur secondary to alterations in the composition of callosal myelin. This study confirms and extends prior morphological studies that have reported age-related dimensional changes in the corpus callosum and, in addition, provides evidence of age-related biophysical tissue differences in the human corpus callosum.

Cystic solitary intracerebral metastasis from prostate adenocarcinoma

Brain metastases from prostate adenocarcinoma are rare; spread to brain as the only site of metastasis is even rarer. We present a patient with a large, cystic, solitary intracerebral metastasis from prostate adenocarcinoma. The pertinent literature is reviewed.

Electronic spectra of 1-methyl and 2-methyl phenanthrenes and their radical cations

Electronic spectra of phenanthrene (P), 1-methyl phenanthrene (1-MeP), 2-methyl phenanthrene (2-MeP) and their monopositive ions are investigated experimentally as well as theoretically. The ions were produced by photo-oxidation of the hydrocarbons in boric acid matrix. The electronic absorption spectrum of 2-methyl phenanthrene cation (2-MeP+) is entirely new. For the interpretation of the electronic spectra of neutral and ionized MePs, semi-empirical AM1 (Austin Model 1) calculations are carried out for the first time. The bathochromic shifts in the spectral bands of the neutral and ionized MePs are attributed to 'conjugative' effect. The present experiments reveal that the 448 nm band of 1-methyl phenanthrene cation (1-MeP+) and the 486 nm band of 2-MeP+ show close matching with the respective 450 nm and 488 nm 'diffuse interstellar bands'. This suggests the possibility of the existence of such ionic species in the interstellar matter.

Vagus nerve stimulation. A potential therapy for resistant depression?

VNS builds on a long history of investigating the relationship of autonomic signals to limbic and cortical function and is one of the newest methods to physically alter brain function. VNS is a clinically useful anticonvulsant therapy in treatment resistant patients with epilepsy, and pilot data suggest that it has potential as an antidepressant therapy. The known anatomic projections of the vagus nerve suggest that VNS also might have other neuropsychiatric applications. Additional research is needed to clarify the mechanisms of action of VNS and the potential clinical utility of this intriguing new somatic portal into the CNS.

Cranial nerve root entry zone primary cerebellopontine angle gliomas: a rare and poorly recognized subset of extraparenchymal tumors

With the exception of patients with neurofibromatosis type II, pediatric extraparenchymal cerebellopontine angle (CPA) tumors of any sort are extremely rare. Most gliomas encountered in the CPA in either children or adults involve the CPA as exophytic extensions of primary brain stem and/or cerebellar tumors. We encountered an unusual case of a giant CPA pilocytic astrocytoma arising from the proximal trigeminal nerve, completely separate from the brain stem. A nine-year-old girl with no evidence for any neurocutaneous syndrome, presented with headaches, mild obstructive hydrocephalus, trigeminal hypesthesia and a subtle peripheral facial paresis. Pre-operative neuroimaging suggested a petroclival meningioma. The tumor was completely resected via a right pre-sigmoid, retro-labyrinthine, subtemporal, transtentorial ('petrosal') approach, using intraoperative neurophysiological monitoring, with minimal morbidity. This appears to be the first reported case of a pediatric primary CPA glioma and the seventh reported case of primary CPA glioma, overall. It represents the second reported case of a primary CPA pilocytic astrocytoma. Given the findings in this case and the six other cases of primary CPA gliomas reported in the literature, as well as the results of histological studies of normal cranial nerves, we hypothesize that the point of origin of these rare and unusual tumors is the root entry zone of the involved cranial nerves. The differential diagnosis of primary CPA tumors should be expanded to include cranial nerve root entry zone primary CPA gliomas.

Green tea polyphenols and tannic acid act as potent inhibitors of phorbol ester-induced nitric oxide generation in rat hepatocytes independent of their antioxidant properties

The deleterious effects of excessive release of nitric oxide (NO) have been implicated in the tissue damage and inflammation. In this study, the effect of various flavonoids and other oxidant scavenging chemical agents have been studied for their ability to inhibit 12-O-tetradecanoyl phorbol 13-acetate (TPA)-induced NO generation in rat hepatocyte. Hepatocytes activated with TPA (25-200 nM) released NO in a concentration- and time-dependent manner. Green tea polyphenols (GTP) and tannic acid (TA) were most effective in inhibiting TPA-induced NO generation (90%). These agents were also effective in inhibiting NO formation when added 2 h following TPA addition. The other oxidant scavengers, such as L-histidine, sodium azide, vitamin E and sodium benzoate, were not found to be effective even up to 1.0 mM concentration. These results suggest that TA and GTP are potent inhibitors of NOS activity and the inhibition of TPA-induced NO generation by these polyphenols is independent of their antioxidant activity. It is tempting to speculate that these agents could be utilized in the pharmacological manipulations of NO-dependent pathophysiological responses.

Differential antiproliferative and apoptotic response of sanguinarine for cancer cells versus normal cells

Sanguinarine, derived from the root of Sanguinaria canadendid, has been shown to possess antimicrobial, anti-inflammatory, and antioxidant properties. Here we compared the antiproliferative and apoptotic potential of sanguinarine against human epidermoid carcinoma (A431) cells and normal human epidermal keratinocytes (NHEKs). Sanguinarine treatment was found to result in a dose-dependent decrease in the viability of A431 cells as well as NHEKs albeit at different levels because sanguinarine-mediated loss of viability occurred at lower doses and was much more pronounced in the A431 carcinoma cells than in the normal keratinocytes. DNA ladder assay demonstrated that compared to vehicle-treated control, sanguinarine treatment of A431 cells resulted in an induction of apoptosis at 1-, 2-, and 5-microM doses. Sanguinarine treatment did not result in the formation of a DNA ladder in NHEKs, even at the very high dose of 10 microM. The induction of apoptosis by sanguinarine was also evident by confocal microscopy after labeling the cells with annexin V. This method also identified necrotic cells, and sanguinarine treatment also resulted in the necrosis of A431 cells. The NHEKs showed exclusively necrotic staining at high doses (2 and 5 microM). We also explored the possibility of cell cycle perturbation by sanguinarine in A431 cells. The DNA cell cycle analysis revealed that sanguinarine treatment did not significantly affect the distribution of cells among the different phases of the cell cycle in A431 cells. We suggest that sanguinarine could be developed as an anticancer drug.

Involvement of nitric oxide in nickel-induced hyperglycemia in rats

Nitric oxide is an important bioactive signaling molecule that mediates a variety of normal physiological functions which, if altered, could contribute to the genesis of many pathological conditions, including diabetes. In the present study we have shown the involvement of NO in nickel-induced hyperglycemia in male albino rats. Administration of nickel chloride (25 to 100 micromol/kg; ip) to overnight-fasted rats resulted in significant dose and time-dependent increase in plasma glucose, attaining maximum level at 1 h posttreatment and thereafter decreasing to normal levels by 4 h. The involvement of NO in nickel-induced hyperglycemia was evident by the observation that pretreatment of rats with NG-monomethyl-l-arginine (10 to 50 micromol/kg; ip), an inhibitor of nitric oxide synthase (NOS), significantly attenuated the nickel-mediated increase in the plasma glucose levels in a dose-dependent fashion. The activity of Ca(2+)-dependent NOS (constitutive form, c-NOS) was found to be significantly elevated in adrenals (5.5-fold) and brain (1.4-fold) at 1 and 2 h posttreatment, attaining normal levels by 4 h. In contrast, the activity of c-NOS in pancreas was significantly decreased (2.8-fold) with a concomitant increase (11.6-fold) in inducible NOS (i-NOS) at the same time interval. As observed by immunoblot analysis, a significant increase in i-NOS protein expression in the pancreas was observed at 1 and 2 h posttreatment. This was associated with a significant elevation in cGMP levels in adrenals, brain, and pancreas, possibly via the stimulation of cytosolic guanylate cyclase. This elevation in cGMP was abolished by low concentration of hemoglobin. These effects were associated with the accumulation of nickel in the target tissues. Taken together, our data suggest that nickel causes a significant increase in the levels of (i) cGMP and c-NOS in adrenals and brain and (ii) i-NOS in pancreas. These events may be responsible for modulating the release of insulin from pancreas finally leading to hyperglycemic condition in rats.

Vagus nerve stimulation (VNS) for treatment-resistant depressions: a multicenter study

BACKGROUND

Vagus Nerve Stimulation (VNS) delivered by the NeuroCybernetic Prosthesis (NCP) System was examined for its potential antidepressant effects.

METHODS

Adult outpatients (n = 30) with nonpsychotic, treatment-resistant major depressive (n = 21) or bipolar I (n = 4) or II (n = 5; depressed phase) disorders who had failed at least two robust medication trials in the current major depressive episode (MDE) while on stable medication regimens completed a baseline period followed by NCP System implantation. A 2-week, single-blind recovery period (no stimulation) was followed by 10 weeks of VNS.

RESULTS

In the current MDE (median length = 4.7 years), patients had not adequately responded to two (n = 9), three (n = 2), four (n = 6), or five or more (n = 13) robust antidepressant medication trials or electroconvulsive therapy (n = 17). Baseline 28-item Hamilton Depression Rating Scale (HDRS(28)) scores averaged 38.0. Response rates (> or =50% reduction in baseline scores) were 40% for both the HDRS(28) and the Clinical Global Impressions-Improvement index (score of 1 or 2) and 50% for the Montgomery-Asberg Depression Rating Scale. Symptomatic responses (accompanied by substantial functional improvement) have been largely sustained during long-term follow-up to date.

CONCLUSIONS

These open trial results suggest that VNS has antidepressant effects in treatment-resistant depressions.

Vagus nerve stimulation: a new tool for brain research and therapy

Biological psychiatry has a long history of using somatic therapies to treat neuropsychiatric illnesses and to understand brain function. These methods have included neurosurgery, electroconvulsive therapy, and, most recently, transcranial magnetic stimulation. Fourteen years ago researchers discovered that intermittent electrical stimulation of the vagus nerve produces inhibition of neural processes, which can alter brain electrical activity and terminate seizures in dogs. Since then, approximately 6000 people worldwide have received vagus nerve stimulation for treatment-resistant epilepsy. We review the neurobiology and anatomy of the vagus nerve and provide an overview of the vagus nerve stimulation technique. We also describe the safety and potential utility of vagus nerve stimulation as a neuroscience research tool and as a putative treatment for psychiatric conditions. Vagus nerve stimulation appears to be a promising new somatic intervention that may improve our understanding of brain function and has promise in the treatment of neuropsychiatric disorders.

Prostate cancer chemoprevention by green tea: in vitro and in vivo inhibition of testosterone-mediated induction of ornithine decarboxylase

Recently, we have shown that ornithine decarboxylase (ODC), a rate-controlling enzyme in the polyamine biosynthetic pathway, is overexpressed in prostate cancer (PCA) and prostatic fluid in humans (R. R. Mohan et al., Clin. Cancer Res., 5: 143-147, 1999). ODC is also characterized as an androgen-responsive gene, and the androgenic stimulation regulates the development and growth of both normal and tumorigenic prostate cells. Thus, chemopreventive approaches aimed toward the modulation of ODC could be effective against PCA. Green tea polyphenols (GTPs) possess strong chemopreventive properties against a variety of animal tumor models and in some human epidemiological studies. At least two epidemiological studies have suggested that people who consume tea regularly may have a decreased risk of PCA. In this study, we investigated the effect of GTPs against testosterone-mediated induction of ODC in human prostate carcinoma cells, LNCaP as an in vitro model, and in Cpb:WU rats and C57BL/6 mice as in vivo models. Treatment of LNCaP cells with testosterone resulted in induction of ODC activity in a dose-dependent manner. Pretreatment of the cells with GTPs resulted in a significant inhibition of testosterone-caused induction of ODC activity in a dose-dependent manner. Similar effects of GTPs were observed in anchorage-independent growth assay of LNCaP cells where pretreatment of the cells with GTP was found to result in dose-dependent inhibition of colony formation. Testosterone treatment of the cells resulted in a significant increase in the level of ODC mRNA, and this increase was almost completely abolished by prior treatment of the cells with GTPs. The administration of testosterone (10 mg/kg body weight, i.p.) to sham-operated and castrated Cpb:WU rats resulted in 2- and 38-fold increases in ODC activity, respectively, in the ventral prostate. Oral feeding of 0.2% GTPs in drinking water for 7 days before testosterone administration resulted in 20 and 54% decreases in testosterone-caused induction of ODC activity in sham-operated and castrated rats, respectively. Similar results were obtained with C57BL/6 mice, where testosterone treatment at similar dosage resulted in a 2-fold increase in ODC activity in the ventral prostate and prior oral feeding with 0.2% GTPs resulted in 40% inhibition in this induction.

Effects of nicardipine and labetalol on the acute hemodynamic response to electroconvulsive therapy

STUDY OBJECTIVE

To examine the acute hemodynamic effects of intravenous (i.v.) nicardipine and its ability to attenuate the hyperdynamic response to electroconvulsive therapy (ECT), when used alone or in combination with labetalol.

DESIGN

Prospective, randomized, double-blind, positive-control, clinical investigation.

SETTING

University hospital.

PATIENTS

36 patients undergoing ECT.

INTERVENTIONS

In a series of three studies, the hemodynamic effects of nicardipine were assessed prior to, during, and after ECT. After administration of glycopyrrolate 0.1 mg i.v., placebo (saline) or nicardipine was administered by rapid infusion (1, 2.5, 5, 10, and 15 mg) or bolus injection (1.25, 2.5, and 5 mg), either alone or in combination with labetalol 10 mg i.v. Unconsciousness was induced with methohexital 1 mg/kg i.v.; succinylcholine 1.2 to 1.5 mg/kg i.v. was administered for muscle relaxation. A bilateral electrical stimulus was delivered and the durations of motor and electroencephalographic (EEG) seizures were noted.

MEASUREMENTS AND MAIN RESULTS

Mean arterial pressure (MAP) and heart rate (HR) values were recorded at 1- to 5-minute intervals throughout the study period. When administered as a rapid infusion, nicardipine 5 mg i.v. produced a significant decrease in MAP; however, nicardipine dosages of 10 to 15 mg i.v. did not produce a significantly greater decrease in MAP than 5 mg. Bolus administration of nicardipine 1.25 to 5 mg produced a rapid onset of its hemodynamic effects without exacerbating the cardiovascular depressant effects of methohexital. However, the decrease in MAP was accompanied by an increase in HR after administration of the 5 mg i.v. bolus dose. The acute hyperdynamic response to ECT was most effectively controlled by nicardipine 2.5 to 5 mg i.v. bolus, in combination with labetalol 10 mg i.v. Seizure duration was not significantly altered by the use of nicardipine as part of the anesthetic regimen for ECT.

CONCLUSION

Nicardipine 2.5 mg i.v. bolus in combination with labetalol 10 mg i.v. was the most effective pretreatment regimen for preventing the acute hyperdynamic response to ECT. However, this combination produced a 20% decrease in MAP immediately prior to ECT and a lower MAP at the time of discharge.

Is oral clonidine effective in modifying the acute hemodynamic response during electroconvulsive therapy?

Clonidine decreases the stress-induced sympathoadrenal responses to painful stimuli and improves hemodynamic stability during general anesthesia. Because acute hypertensive responses are often observed immediately after electroconvulsive therapy (ECT), we designed a prospective, randomized, placebo-controlled, cross-over study to assess the effects of four different oral doses of clonidine (0.05-0.3 mg per os) on the acute hemodynamic response to ECT. Anesthesia was induced with methohexital 1 mg/kg followed by succinylcholine, 1.3 mg/kg i.v. A total of 110 treatments were evaluated in 22 patients. Noninvasive mean arterial pressure (MAP) and heart rate (HR) values, duration of motor and electroencephalographic (EEG) seizure activity, and recovery times were recorded. Clonidine produced a dose-related decrease in MAP before and after ECT. Although clonidine 0.2-0.3 mg per os decreased the peak MAP value after ECT, the changes in MAP from the prestimulation values were similar in all treatment groups. Clonidine produced no significant changes in HR, duration of motor and EEG seizure activity, or recovery times after anesthesia. These data suggest that clonidine decreases the peak MAP value after ECT by decreasing MAP immediately before the ECT stimulus.

IMPLICATIONS

Oral clonidine (0.2-0.3 mg) decreases the acute hypertensive response after electroconvulsive therapy; however, this antihypertensive effect was achieved by decreasing the blood pressure before the electrical stimulus.

Acute hemodynamic responses to electroconvulsive therapy are not related to the duration of seizure activity

STUDY OBJECTIVE

To test the hypothesis that the magnitude of the acute hemodynamic response to electroconvulsive therapy (ECT) is related to the duration of the seizure activity in patients receiving different dosages of intravenous (i.v.) lidocaine.

DESIGN

Randomized, double-blind, placebo-controlled, cross-over study.

SETTING

University-affiliated hospital.

PATIENTS

21 ASA physical status I, II, and III patients undergoing four consecutive maintenance ECT treatments for chronic depression.

INTERVENTIONS

Patients received lidocaine 50 mg, 100 mg, 200 mg i.v., or saline prior to induction of anesthesia via a standardized anesthetic technique.

MEASUREMENTS AND MAIN RESULTS

Noninvasive blood pressure (BP) and heart rate (HR), as well as the duration of motor and electroencephalographic (EEG) seizure, were measured. The duration of motor and EEG seizures (means +/- SD) were 37 +/- 13 sec and 64 +/- 21 sec, 25 +/- 11 sec and 52 +/- 43 sec, 17 +/- 12 sec and 32 +/- 17 sec, 1 +/- 3 sec and 18 +/- 10 sec in the saline, lidocaine 50 mg, 100 mg, 200 mg groups, respectively. Although the duration of seizure activity was decreased in a dose-related fashion after lidocaine pretreatment, the peak increases in BP and HR were similar in the lidocaine and saline treatment groups.

CONCLUSIONS

Despite producing dose-related decreases in the duration of both motor and EEG seizure activity, lidocaine failed to attenuate the acute hemodynamic response to ECT. Thus, the acute hemodynamic response to ECT is not related to the duration of seizure activity.

In vitro 1H-magnetic resonance spectroscopy of postmortem brains with schizophrenia

Some evidence suggests that thalamic dysfunction could explain some of the signs and symptoms of schizophrenia. We measured the absolute concentrations of amino acid metabolites in thalamus, frontal pole, and cerebellar vermis in extracts of postmortem brains from 8 schizophrenics and 10 controls using high-resolution 1H-magnetic resonance spectroscopy. The concentrations of N-acetyl aspartate, glutamate, and valine tended to be reduced in the thalamus of the schizophrenic group. Although it is difficult to ascribe significance to the "tendencies," these data may tend to support other data suggesting decreased thalamic volume or neuronal number in schizophrenia.

Regional metabolic alterations in Alzheimer's disease: an in vitro 1H NMR study of the hippocampus and cerebellum

The concentrations of selected metabolites in the hippocampus and cerebellum of 13 Alzheimer's diseased (AD) and four nondemented postmortem brains were measured using high resolution 1H NMR spectroscopy. For both the hippocampal region and the cerebellum, the putative neuronal marker N-acetyl aspartate (NAA) was significantly lower in AD brains relative to the nondemented brains. For the hippocampal region, the NAA concentration correlated inversely with semiquantitative assessments of neuronal loss and neurofibrillary tangles. The gamma-aminobutyric acid levels in both hippocampus and cerebellum of an age- and a postmortem interval-matched subset of AD brains were lower than those of the controls. Because the cerebellum is generally thought to be unaffected by AD, the NAA decrease in the Alzheimer cerebellum may be due to lesions of either the Alzheimer or non-Alzheimer type in contralateral cerebrum.

The suboccipital cavernous sinus

The authors studied the microsurgical anatomy of the suboccipital region, concentrating on the third segment (V3) of the vertebral artery (VA), which extends from the transverse foramen of the axis to the dural penetration of the VA, paying particular attention to its loops, branches, supporting fibrous rings, adjacent nerves, and surrounding venous structures. Ten cadaver heads (20 sides) were fixed in formalin, their blood vessels were perfused with colored silicone rubber, and they were dissected under magnification. The authors subdivided the V3 into two parts, the horizontal (V3h) and the vertical (V3v), and studied the anatomical structures topographically, from the superficial to the deep tissues. In two additional specimens, serial histological sections were acquired through the V3 and its encircling elements to elucidate their cross-sectional anatomy. Measurements of surgically and clinically important features were obtained with the aid of an operating microscope. This study reveals an astonishing anatomical resemblance between the suboccipital complex and the cavernous sinus, as follows: venous cushioning; anatomical properties of the V3 and those of the petrous-cavernous internal carotid artery (ICA), namely their loops, branches, supporting fibrous rings, and periarterial autonomic neural plexus; adjacent nerves; and skull base locations. Likewise, a review of the literature showed a related embryological development and functional and pathological features, as well as similar transitional patterns in the arterial walls of the V3 and the petrous-cavernous ICA. Hence, due to its similarity to the cavernous sinus, this suboccipital complex is here named the "suboccipital cavernous sinus." Its role in physiological and pathological conditions as they pertain to various clinical and surgical implications is also discussed.

Decreased mesopontine choline acetyltransferase levels in schizophrenia. Correlations with cognitive functions

The objective was to replicate a reported decrease of choline acetyltransferase (ChAT) in the mesopontine tegmentum of deceased schizophrenics and to see if such a decrease is related to their cognitive status as measured during life. Rigorous antemortem psychiatric evaluations were performed on our large population of schizophrenic patients. Mesopontine tissue was collected promptly following death from eight of these patients, from an additional five schizophrenics without systematic premortem psychiatric evaluation, and from control subjects. ChAT content of this brain tissue was determined using Western immunoblot analysis. There were 13 schizophrenic patients and 8 control subjects. The mean age of subjects in the two groups was similar (64 +/- 9 yr vs 63 +/- 10 yr). Even in the face of reduced post mortem intervals in the patients with schizophrenia, mesopontine tegmental ChAT concentrations were depressed by 70% in schizophrenic patients (1.28 +/- 1.74 vs 4.39 +/- 3.20 ng ChAT/micrograms tissue protein, P < 0.01), and correlated with orientation and reasoning (rs = 0.90 and 0.98, respectively) in those subjects assessed antemortem. Mesopontine ChAT concentrations are depressed in schizophrenia and correlate significantly with measures of cognitive performance in patients with this disorder.

Metal-independent putative superoxide dismutase mimics in chemistry, biology, and medicine

The excessive generation of superoxide radicals O2-. with inadequate available defence provided by the enzyme superoxide dismutase (SOD) may result in the development and exacerbation of many of mankind's common illnesses. The native SOD proves too problematic to be used for the prevention and cure of such diseases. A number of metal-independent synthetic SOD mimics, based on organic nitroxides, have been tried as therapeutic interventions. Among the widely studied mimics, 2-ethyl-2,5,5-trimethyl-3-oxazolidinanyl, 2,2,6,6-tetramethyl-1-piperidimyloxy, nitrosoureas, and triazene derivatives have indicated promising results with possible future applications in chemistry, biology, and medicine.

Evidence for the involvement of nitric oxide in cisplatin-induced toxicity in rats

Cisplatin treatment of rats results into a significant increase in the activity of Ca(2+)-independent nitric oxide synthase (NOS) in kidneys and liver. Significant enhancement of lipid peroxidation in gastric mucosa, kidneys and liver was also observed. The administration of NG-nitro-L-arginine methyl ester, an inhibitor of NOS, markedly reduced renal and gastrointestinal toxicity, and also decreased the content of blood urea nitrogen, serum creatinine, and incidence of diarrhoea along with a significant inhibition in lipid peroxidation in the target organs. The present report, while demonstrating the beneficial effect of the blockade of NO pathways during cisplatin chemotherapy, may be helpful in developing strategies for combating some of the toxic side-effects of the drug.

Comparative evaluation of chelating agents on the mobilization of cadmium: a mechanistic approach

A comparative evaluation of chelating agents, namely, diethyl dithiocarbamate (DDC), dimethyl dithiocarbamate (DMDC), 1,4,8,11-tetraazacyclotetradecane (CYCLAM), 1,4,8,12-tetraazacyclopentadecane (TACPD), 2,3-dimercaptosuccinic acid (DMSA), and 2,3-dimercapto-1-propane sulfonate (DMPS) was conducted to assess their efficacy against acute cadmium (Cd) toxicity. DMSA and DMPS appeared to be most effective in reducing mortality as well as Cd burden of liver, kidneys, and brain in cadmium intoxicated mice. DMDC reduced Cd levels only in liver and kidneys, while DDC significantly enhanced its level in brain. CYCLAM and TACPD significantly increased the Cd level in liver and kidneys and were ineffective in brain. The therapeutic index as well as therapeutic efficacy was highest for DMSA followed by DMPS and DMDC. A fair degree of correlation was found to exist between (1) stability constant of Cd chelates and percent survival (r = .438, (2) stability constant and percent transport (r = .479), and (3) percent survival and percent transport (r =.447). However, the lipophilicity did not show any appreciable correlation with percent survival and stability constant of Cd chelates.

The comparative effects of methohexital, propofol, and etomidate for electroconvulsive therapy

The intravenous anesthetics which are commonly used for electroconvulsive therapy (ECT) possess dose-dependent anticonvulsant properties. Since the clinical efficacy of ECT depends on the induction of a seizure of adequate duration, it is important to determine the optimal dose of the hypnotic for use during ECT. We compared the duration of seizure activity and cognitive recovery profiles after different doses of methohexital, propofol, and etomidate administered to induce hypnosis prior to ECT. Ten outpatients with major depressive disorders receiving maintenance ECT participated in this prospective, randomized, cross-over study. Patients were premedicated with glycopyrrolate, 0.2 mg intravenously (i.v.), and labetalol, 20-30 mg i.v., and hypnosis was induced with an i.v. bolus injection of methohexital or propofol (0.75, 1.0, and 1.5 mg/kg), or etomidate (0.15, 0.2, and 0.3 mg/kg), administered over 10-15 s. Adequate muscle paralysis was achieved with succinylcholine, 1.0-1.4 mg/kg i.v. Each patient's seizure threshold was determined prior to enrollment in the study and the electrical stimulus variables were kept constant throughout the study period. After delivery of a bilateral electrical stimulus, the duration of the resulting electroencephalographic (EEG) and motor seizures were recorded. A total of 90 ECT treatments were evaluated. The durations of EEG and motor seizures were longest after etomidate and shortest after propofol. There were no significant dose-related differences in motor and EEG seizure durations (means +/- SD) after the low, intermediate, and high doses of etomidate of 44 +/- 11 and 77 +/- 19, 43 +/- 10 and 76 +/- 34, 42 +/- 16 and 78 +/- 56 s, respectively. Conversely, both methohexital and propofol, 0.75, 1.0, and 1.5 mg/kg, produced dose-dependent decreases in motor and EEG seizure durations (i.e., 37 +/- 10 and 58 +/- 12, 36 +/- 8 and 62 +/- 24, and 29 +/- 13 and 48 +/- 20 for methohexital; 34 +/- 15 and 56 +/- 29, 31 +/- 8 and 50 +/- 17, and 20 +/- 6 and 33 +/- 12 for propofol, respectively). The awakening times were similar, regardless of the hypnotic or dose administered.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of cis-platinum induced nephrotoxicity by zinc histidine complex : the possible implication of nitric oxide

Cisplatin is a prominent member of the effective broad spectrum antitumor drugs. The clinical usage of cisplatin is, however, restricted due to some adverse side effects including renal toxicity. The present study demonstrates the protective effect of a Zinc-chelate of histidine, [Zn-Hist], against cisplatin induced nephrotoxicity and gastrointestinal toxicity as shown by decreases in BUN, creatinine and lower incidence of diarrhoea. The observed inhibition in cisplatin induced renal and hepatic lipid peroxidation by [Zn-Hist] pretreatment, suggests an importance for Zn in stabilisation of membrane integrity probably through the displacement of the redox-active metals that may be responsible for inducing peroxidative damage at target sites. The findings also suggest that cisplatin may play biochemical role in arginine-metabolism including nitric oxide (NO) production.

Exacerbation of nickel induced oxidative response by vitamin E

Vitamin E (alpha-tocopherol), a well known naturally occurring chain breaking antioxidant and a free radical scavenger was found to exacerbate nickel (Ni) toxicity in mice. Vitamin E (Vit. E) mediated enhancement of nickel toxicity was demonstrated by (i) enhanced mortality in mice treated with Ni and Vit. E (ii) increased hepatic lipid peroxidation, (iii) increased rate of benzoate hydroxylation, and (iv) liposomal membrane damage.

Sporadic encephalitis lethargica: a case treated successfully with ECT

A patient who presented with seizures, opisthotonos, catatonia, and autonomic dysfunction developed features consistent with sporadic encephalitis lethargica. She received a course of ECT and had full recovery.

An in vitro 1H nuclear magnetic resonance study of the temporoparietal cortex of Alzheimer brains

The concentrations of selected metabolites in the posterior temporoparietal cortex of 13 Alzheimer's diseased (AD) and four nondemented postmortem brains (of individuals between the ages of 63 and 95) were determined using high-resolution 1H nuclear magnetic resonance (NMR) spectroscopy. The estimates for glutamate and inositol for AD brains did not show any statistically significant difference (P > 0.05) from those for the nondemented brains. The putative neuronal marker N-acetyl aspartate (NAA), creatine, and GABA were decreased in AD brains compared with the nondemented brains. The estimates for creatine, glutamate, and GABA showed significant linear correlations with those of NAA. Creatine, glutamate, GABA, and NAA appeared to be negatively correlated with the neurofibrillary tangles. Our results support a neuronal loss in the posterior temporoparietal cortices of AD brains.

Anaesthesia for electroconvulsive therapy: use of propofol revisited

In three clinically depressed patients undergoing repeated electroconvulsive therapy (ECT) with either propofol or methohexitone, dose-dependent decreases in the duration of motor and EEG seizure activity were noted. Use of a 'minimally' hypnotic dose of propofol (0.75-1.0 mg kg-1) was associated with a seizure duration which was comparable to standard hypnotic doses of methohexitone. We conclude that doses of propofol < 1.5 mg kg-1 are associated with a clinically acceptable duration of EEG seizure activity (> 30 s) during ECT.

Anesthesia for electroconvulsive therapy: effects of propofol and methohexital on seizure activity and recovery

The influence of methohexital and propofol on seizure activity and recovery profiles was assessed in a randomized, crossover study involving 13 adult outpatients undergoing electroconvulsive therapy (ECT). Arterial blood pressure, heart rate, hemoglobin oxygen saturation, and electroencephalogram (EEG) activity were monitored during the ECT procedure. After premedication with glycopyrrolate, 0.2 mg intravenously (i.v.), and labetalol 20-30 mg i.v. hypnosis was induced with a bolus injection of either methohexital or propofol, 0.75 mg/kg. Muscle paralysis was achieved by administering succinylcholine, 1.4 mg/kg i.v. Ventilation was assisted using a face mask while administering 100% oxygen. Thereafter, an electrical stimulus was administered and the length of the resulting motor and EEG seizures was measured. Mood level and cognitive function were assessed prior to induction of anesthesia and after ECT. A total of 72 treatment sessions were evaluated. Each patient underwent a minimum of four treatments and received both induction drugs equally. Although the use of propofol was associated with significantly shorter motor and EEG seizure durations (mean +/- SEM) compared with methohexital (34 +/- 1.6 s and 52 +/- 2.9 s vs 39 +/- 1.5 s and 61 +/- 3.0 s, respectively), this difference was not clinically significant because the durations exceeded 30 s in both groups. Although awakening times were similar, both hemodynamic stability and cognitive recovery were more favorable after propofol. Compared with methohexital, the use of propofol was associated with a clinically insignificant decrease in seizure duration. However, propofol was associated with improved hemodynamic stability and an earlier return of cognitive function after ECT.

Acrylamide induced immunosuppression in rats and its modulation by 6-MFA, an interferon inducer

In the present communication, we describe acrylamide (ACR) induced immunotoxicity and its modulation by an interferon inducer, the 6th mycelial fraction acetone (6-MFA) of Aspergillus ochraceus ATCC 28706. ACR administration to rats produced a significant decrease in the weight of spleen (p < 0.001), thymus (p < 0.001) and mesenteric lymph nodes (p < 0.05). A decrease in cellularity of spleen (p < 0.001), thymus (p < 0.001), bone marrow (p < 0.001) and circulating blood lymphocyte population (p < 0.001) was also recorded. ACR suppressed the humoral as well as cell mediated immunity as assessed by erythrocyte antibody complement (EAC)-rosettes (p < 0.001), hemagglutination titre (p < 0.001), PFC (p < 0.001) and the delayed type hypersensitivity response against sheep red blood cells (SRBC, p < 0.001). ACR treated immunosuppressed rats when treated with 6-MFA restored the circulating lymphocyte number to the normal level and a partial recovery in the weight of spleen and thymus. Potentiation of EAC-rosettes, hemagglutination titre, IgM-PFC and DTH response against SRBC was observed. It is concluded that 6-MFA ameliorate the ACR induced toxicity. This study may be of significance in prevention of ACR toxicity.

Bicaudate index on magnetic resonance imaging: effects of normal aging

The bicaudate and bifrontal indices have been used in prior computed tomographic studies to investigate atrophy of the caudate nuclei in patients with Huntington's chorea and cerebral atrophy. However, the relationship between these indices and caudate volume has not been documented previously. In this study, we used high-field magnetic resonance imaging (MRI) to determine the effects of normal aging on the bicaudate and bifrontal indices and to study the relationship between these indices and caudate volume. The subjects were 49 normal volunteers, aged 22 to 82 years, who were without any significant neurologic or psychiatric disorders. Age was positively correlated with bicaudate index (r = .59; P < .0001) and bifrontal index (r = .40; P < .0047). Age was negatively correlated with caudate nuclei volume (r = -.47; P < .0005). Caudate volume was negatively correlated with bicaudate (r = -.27; P < .06) and bifrontal (r = -.31; P < .03) indices. These findings are consistent with prior reports of caudate nuclei degeneration with increasing age. Linear and volumetric caudate measurements with MRI may prove useful in the investigation of caudate nuclei function in the neuromotor decline with normal aging and in disorders such as Huntington's chorea.