Accuracy of the Montreal Cognitive Assessment tool for detecting mild cognitive impairment: A systematic review and meta-analysis

INTRODUCTION

This systematic review evaluates the accuracy of the Montreal Cognitive Assessment (MoCA) for detecting mild cognitive impairment (MCI).

METHODS

We searched MEDLINE, PSYCInfo, EMBASE, and Cochrane CENTRAL (1995-2021) for studies comparing the MoCA with validated diagnostic criteria to identify MCI in general practice. Screening, data extraction, and risk of bias assessment were performed independently, in duplicate. Pooled sensitivity and specificity for MoCA cutoffs were estimated using bivariate meta-analysis.

RESULTS

Thirteen studies [2158 participants, 948(44%) with MCI] were included; 10 used Petersen criteria as the reference standard. Risk of bias of studies were high or unclear for all domains except reference standard. Sensitivity and specificity were 73.5%(95% confidence interval: 56.7-85.5) and 91.3%(84.6-95.3) at cutoff <23; 79.5%(67.1-88.0) and 83.7%(75.4-89.6) at cutoff <24; and 83.8%(75.6-89.6) and 70.8(62.1-78.3) at cutoff <25.

DISCUSSION

MoCA cutoffs <23 to <25 maximized the sum of sensitivity and specificity for detecting MCI. The risk of bias of included studies limits confidence in these findings.

Subjective difficulty in a verbal recognition-based memory task: Exploring brain-behaviour relationships at the individual level in healthy young adults

The vast majority of fMRI studies of task-related brain activity utilize common levels of task demands and analyses that rely on the central tendencies of the data. This approach does not take into account perceived difficulty nor regional variations in brain activity between people. The results are findings of brain-behavior relationships that weaken as sample sizes increase. Participants of the current study included twenty-six healthy young adults evenly split between the sexes. The current work utilizes five parametrically modulated levels of memory load centered around each individual's predetermined working memory cognitive capacity. Principal components analyses (PCA) identified the group-level central tendency of the data. After removing the group effect from the data, PCA identified individual-level patterns of brain activity across the five levels of task demands. Expression of the group effect significantly differed between the sexes across all load levels. Expression of the individual level patterns demonstrated a significant load by sex interaction. Furthermore, expressions of the individual maps make better predictors of response time behavior than group-derived maps. We demonstrated that utilization of an individual's unique pattern of brain activity in response to increasing a task's perceived difficulty is a better predictor of brain-behavior relationships than study designs and analyses focused on identification of group effects. Furthermore, these methods facilitate exploration into how individual differences in patterns of brain activity relate to individual differences in behavior and cognition.

Outcomes of transfemoral-transcatheter aortic valve replacement with Sapien-3 valve in liver cirrhosis patients

Background

Little is known about the outcomes of liver cirrhosis patients with severe aortic stenosis (AS) who undergo transcatheter aortic valve replacement (TAVR).

Methods

We undertook a retrospective analysis of consecutive patients with severe symptomatic AS who underwent transfemoral-TAVR with Sapien-3 valve at our Clinic between April 2015 and December 2018, yielding 32 patients with liver cirrhosis on imaging including ultrasound and/or computed tomography. Their baseline characteristics, procedural and long-term outcomes after TAVR with the non-cirrhotic group were compared, along with their management strategies as per the hepatology team.

Results

Among 1028 patients, 32 were assigned to the cirrhosis, and 996 were assigned to the non-cirrhosis (control) group. Compared with the control group cirrhotic patients were slightly younger in age (74.5 vs 81.2 years), had a slightly higher BMI (31.3 vs 29.3), and had a higher incidence of prior history of myocardial infarction (38% vs 33%). Baseline variables including the history of smoking, hypertension, diabetes, and atrial fibrillation were comparable in both groups. Among cirrhotic patients (n=32), the most common etiologies were non-alcoholic steatohepatitis (NASH) (37.5%), Alcoholism (18.75%), and Hepatitis C (12.5%). The mean MELD-NA score was 11.8 and 67% of patients were Child PUGH Class A and 33% were Child PUGH Class B and all patients had a Child PUGH score of ≥5. 53% of patients (n=17) in the cirrhosis group were evaluated by Hepatology and 12.5% (n=4) were evaluated for a liver transplant but only 1 patient had a liver transplant post-TAVR. Compared with the control group cirrhotic patients had similar 1-year mortality (12% vs 12%, p=1), had a lower rate of 30-day new pacemaker post tavr (6% vs 9% p=0.85), had a higher rate of 1-year readmission for heart failure (12% vs 5% p=0.12) and similar 1-year major adverse cardiac and cerebrovascular event (MACCE) rate (15% vs 14% p=0.98)

Conclusion

Patients with severe AS undergoing TAVR with concomitant liver cirrhosis demonstrate comparable outcomes compared with their non- cirrhotic counterparts. NASH followed by alcoholic cirrhosis was found to be most common etiology.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Microglial activation increases cocaine self-administration following adolescent nicotine exposure

With the rise of e-cigarette use, teen nicotine exposure is becoming more widespread. Findings from clinical and preclinical studies show that the adolescent brain is particularly sensitive to nicotine. Animal studies have demonstrated that adolescent nicotine exposure increases reinforcement for cocaine and other drugs. However, the mechanisms that underlie these behaviors are poorly understood. Here, we report reactive microglia are critical regulators of nicotine-induced increases in adolescent cocaine self-administration. Nicotine has dichotomous, age-dependent effects on microglial morphology and immune transcript profiles. A multistep signaling mechanism involving D2 receptors and CX3CL1 mediates nicotine-induced increases in cocaine self-administration and microglial activation. Moreover, nicotine depletes presynaptic markers in a manner that is microglia-, D2- and CX3CL1-dependent. Taken together, we demonstrate that adolescent microglia are uniquely susceptible to perturbations by nicotine, necessary for nicotine-induced increases in cocaine-seeking, and that D2 receptors and CX3CL1 play a mechanistic role in these phenomena.

Adolescents are particularly sensitive to nicotine. Here the authors show that in mice, microglial activation contributes to the enhanced sensitivity to cocaine caused by nicotine exposure in young mice.

Early Progressive Maxillary Changes with Nasoalveolar Molding: Randomized Controlled Clinical Trial

OBJECTIVES

Quantitative assessment of 3-dimensional progressive changes of the maxillary geometry in unilateral cleft lip palate (UCLP) with and without nasoalveolar molding (NAM).

METHODS

The study was designed as a prospective 2-arm randomized controlled clinical trial conducted in parallel. Forty infants with nonsyndromic UCLP were randomly assigned into a NAM-treated group (n = 20) and non-NAM treated group (n = 20). A total of 120 laser-scanned maxillary casts were collected and blindly analyzed via a modified algorithm at T0 (initial visit; baseline), T1 (after 3 wk; first interval), and T2 (after 6 wk; second interval). The main outcome measures were the amount and rate of cleft gap changes, the midline position, and the transverse, sagittal, and vertical growth through intervals.

RESULTS

More than 50% of the cleft gap (56.42%; P < 0.001) was reduced in the first 3 wk of alveolar molding (AM). The end point of the AM was obtained in 6 wk (86.25%; P < 0.001); then, the kinks of the greater segment were noticed. The AM effect decreased as far as posterior; the anterior arch width reduced slightly (1.23%; P < 0.001), while the middle and posterior arches increased slightly (P > 0.999 and P = 0.288, respectively). The posterior arch width was the least changing and was considered a baseline, while the anterior was the pivot of the segment rotation. Both groups showed different patterns of segment rotation and sagittal growth. The non-NAM treated group showed a slight increase in cleft gap length, arch width, and midline position.

CONCLUSION

Based on this study, it was concluded that the NAM treatment is effective in minimizing cleft severity and realigning maxillary segments without the deterioration of the transverse and vertical arch growth. Near follow-up visits are recommended to monitor the rapid gap reduction within the first 3 wk. Further trials are recommended to compare the outcomes regarding the sagittal growth to reference values (ClinicalTrials.gov NCT03029195).

KNOWLEDGE TRANSFER STATEMENT

The results of this study will help clinicians understand nasoalveolar molding biomechanics that may improve the treatment outcomes for patients with unilateral cleft lip and palate. The trial data can be a valuable guide to the qualitative and quantitative predictive virtual molding in computer aided design-simulated nasoalveolar molding therapy. The modified algorithm can be used by researchers to quantify the rate, the sequence, and the direction of the maxillary segments movement in unilateral cleft lip and palate.

P6438Trends of acute kidney injury following percutaneous coronary interventions

Introduction

Acute kidney injury (AKI) is a significant in-hospital complication in patients undergoing percutaneous coronary interventions (PCI) and has been shown to be associated with poor outcomes. Prior studies have shown an upward trend of AKI post PCI which may be related to a multitude of factors. In this study, we aim to discern whether the recent changes in AKI definition, awareness of risk calculators, and preventive measures have been effective in changing the inclining trend.

Methods

Patients who underwent PCI during hospitalization were identified retrospectively in the Nationwide Readmission Database (NRD) from January 2010 to December 2014. All patients older than 18 years were included in the current study. Patient demographics and comorbidities were identified using appropriate ICD-9 codes. The primary outcome is the temporal trends of AKI following PCI and secondary outcomes are temporal trends in mortality, length of stay and hospitalization cost in patients with AKI. Continuous variables were expressed as means ± standard deviation or median (IQR), and categorical variables were expressed as percentages (%). All statistical tests were two-sided.

Results

Among the 2,712,473 patients who underwent PCI from 2010 to 2014, 162,286 (6%) patients developed AKI post PCI. Mean age was 69.22±12.34 years and 65% of them were males. The percentage of cases with AKI rose almost twofold from 2010 to 2014 (4.8% to 8.1%, p-value <0.005), despite the lack of a significant change in patient's demographics and comorbidities over the years. Among patients with a history of Chronic Kidney Disease (CKD) the incidence of AKI increased from 20.3% to 24.2%, and in patients without CKD history the incidence of AKI almost doubled (2.6% to 5.0%) from 2010 to 2014. There was a slight decrease in in-hospital mortality (9.4% to 8.8%) and median length of stay (7 days to 5 days), and a slight increase in the mean cost of hospitalization ($124,755.1 to $133,902.17) from 2010 to 2014.

AKI Incidence and mortality trend

Conclusion

This large cohort study shows a consistent uptrend of AKI in patients undergoing PCI from 2010 to 2014. Despite this, the mortality and length of stay are decreasing while the cost of hospitalization only slightly increased in patients with AKI. Thus, future drives to implement renal protective measures and advanced studies to identify new preventive therapies are needed to reduce the incidence of AKI post-PCI.

P5331Aspirin use for prevention of cardiovascular events in patients with high lipoprotein(a): a population-based study

Background

High lipoprotein(a) [Lp(a)] levels have been shown to increase Myocardial Infarction (MI) and all-cause mortality. However, studies evaluating the optimal preventive measures for that subset of cardiac patients are scarce. This study aims to study the outcomes of aspirin use versus no aspirin for the prevention of all-cause mortality and myocardial infarction in patients with high Lp(a) levels.

Purpose

We sought to determine the effect of Aspirin in reducing the rate of MI and all-cause mortality among patients with high lipoprotein(a) [Lp(a) ≥50mg/dL]

Methods

Patients who attended the preventive cardiology clinic from 2005 to 2016 and included in the Preventive Cardiology Database were included in the current single-center, retrospective, observational cohort study that was conducted according to the guidelines of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology Statement) checklist. The primary outcome was the incidence of myocardial infarction and the secondary outcome was all-cause mortality. Patients were excluded in cases of I) Lp(a)a <50mg/dL, II) history of malignancy, or III) being on anticoagulation/ dual antiplatelet therapy. The median duration of follow-up was 92 months from time of Lp(a) measurement to the last follow-up. Continuous variables were expressed as means ± standard deviation or median (IQR), and categorical variables were expressed as percentages (%). All statistical tests were two-sided. A propensity score-matched analysis was performed with 1:1 nearest match for Age, Gender, Race, Smoking status, BMI, Diabetes, Peripheral artery disease, Carotid artery disease, coronary artery disease, chronic kidney disease, Heart failure, Hypertension, Dyslipidemia, Stroke, family history of coronary artery disease, Lp (a), LDL, HDL, Triglycerides, glucose and total cholesterol.

Results

1,805 patients fulfilled the inclusion and exclusion criteria out of 7,410 patients initially identified with recorded Lp(a) levels in the Preventive Cardiology Database. Of these, 376 patients were taking aspirin, and 1429 patients were not receiving aspirin. After propensity score matching for different baseline characteristics and comorbidities as mentioned above, 316 patients were matched in each group. Patients who were on Aspirin had a significantly lower rate of MI events compared to patients who were not on aspirin (6.96% vs 12.02%, P=0.03) and a lower rate, however statistically non-significant, of all-cause mortality (2.84% vs 4.11%, P=0.385).

Conclusion

The use of aspirin in patients with elevated Lp(a) levels significantly lowers the rate of myocardial infarction events. Larger randomized clinical trials are warranted to evaluate the use of aspirin for primary and secondary prevention of major adverse cardiovascular events in patients with high Lp(a) levels.

P6525Impact of acute arrhythmias on in-hospital mortality in patients undergoing angioplasty

Introduction

Arrhythmia is one of the most common complications in patients undergoing percutaneous coronary interventions (PCI). Prior attempts to address these arrhythmias “aggressively” did not show improvement in survival. This study aims to investigate the impact of acute arrhythmias on in-hospital mortality in patients undergoing angioplasty in the United States.

Methods

Data about patients undergoing PCI between January 2010 and December 2014 on the Nationwide Readmission Database (NRD) was queried from the Healthcare Cost and Utilization Project (HCUP). All patients undergoing PCI were identified with the appropriate ICD-9 procedure codes. Binominal logistic regression testing was utilized to perform a multivariate analysis and different patient baseline characteristics were adjusted for including age, gender, LOS, diabetes mellitus, hypertension, renal failure, and cancer diagnosis. Odds Ratio (OR) of in-hospital mortality following acute arrhythmia were reported alongside 95% Confidence Intervals (CI).

Results

A total of 2,712,078 patients underwent PCI during hospitalization from January 2010 to December 2014. Out of those, 56,985 (2.1%) patients died while hospitalized. Most of the patients who died were older (mean age 70.73±12.9) and males (59.3%). After adjusting for age, female gender, hypertension, diabetes, heart failure, anemia, malignancy, psychiatric disorder, and longer length of stay; ventricular and supraventricular arrhythmias were found to be predictors of in-hospital mortality. Atrial fibrillation had an OR of 1.588 (95% CI: 1.551–1.626), ventricular tachycardia an OR of 2.191 (95% CI: 2.133–2.250), and ventricular fibrillation an OR of 4.143 (95% CI: 4.031–4.258).

Conclusions

Ventricular and supraventricular arrhythmias are independent predictors of in-hospital mortality following angioplasty. Further studies are warranted to evaluate the optimal management for patients with acute arrhythmia following PCI.

Analysis of miR-146a and miR-142-3p as Potential Markers of Freshly Isolated or In Vitro-Expanded Human Treg cells

Regulatory CD4⁺ T cells (Tregs) are pivotal for prevention of autoimmunity. The use of Tregs is therefore of increasing interest in in vitro drug screening assays as well as for a cytotherapy per se against autoimmune disorders. For both purposes, in vitro expansion of peripheral blood Tregs is necessary and there is an increasing need to identify novel markers that can discriminate natural thymic-derived Tregs (tTregs) from other T cell subsets, and ideally, such markers should be stably expressed during in vitro expansion procedures. We screened for novel miRNAs differentially expressed in tTregs and identified miR-146a and 142-3p as possible candidates. We analysed freshly isolated naïve and activated tTregs and non-Treg subsets after or prior to in vitro expansion. We observed a tTreg-specific profile of these miRNAs together with FOXP3 and Helios in freshly isolated tTregs, but observed a decline in the same markers in activated tTregs as opposed to naïve tTregs. In vitro-expanded Tregs could be identified based on FOXP3 expression, but with loss of a discriminate profile for miRNA candidates and a decline in FOXP3 when activated tTregs were expanded. Our data demonstrate miR-146a and 142-3p as potential miRNA markers for discrimination between non-Treg cells and tTregs, but these miRNAs are not stable markers for in vitro-expanded Treg cells. In addition, the loss of FOXP3 in expansion of activated tTregs has implication for in vitro use of this cell subset in immunopharmacological assays and cytotherapy as FOXP3 is pivotal for suppressive function.

Genome-wide gene expression profiling of SCID mice with T-cell-mediated Colitis

Inflammatory bowel disease (IBD) is a multifactorial disorder with an unknown aetiology. The aim of this study is to employ a murine model of IBD to identify pathways and genes, which may play a key role in the pathogenesis of IBD and could be important for discovery of new disease markers in human disease. Here, we have investigated severe combined immunodeficient (SCID) mice, which upon adoptive transfer with concanavalin A-activated CD4(+) T cells develop inflammation of the colon with predominance in rectum. Mice with increasing level of inflammation was studied. RNA from rectum of transplanted and non-transplanted SCID mice was investigated by a genome-wide gene expression analysis using the Affymetrix mouse expression array 430A (MOE430A) including 22,626 probe sets. A significant change in gene expression (P = 0.00001) is observed in 152 of the genes between the non-transplanted control mice and colitis mice, and among these genes there is an overrepresentation of genes involved in inflammatory processes. Some of the most significant genes showing higher expression encode S100A proteins and chemokines involved in trafficking of leucocytes in inflammatory areas. Classification by gene clustering based on the genes with the significantly altered gene expression corresponds to two different levels of inflammation as established by the histological scoring of the inflamed rectum. These data demonstrate that this SCID T-cell transfer model is a useful animal model for human IBD and can be used for suggesting candidate genes involved in the pathogenesis and for identifying new molecular markers of chronic inflammation in human IBD.

Tolerogenic dendritic cells pulsed with enterobacterial extract suppress development of colitis in the severe combined immunodeficiency transfer model

Immunomodulatory dendritic cells (DCs) that induce antigen-specific T-cell tolerance upon in vivo adoptive transfer are promising candidates for immunotherapy of autoimmune diseases. The feasibility of such a strategy has recently proved its efficacy in animal models of allotransplantation and experimental allergic encephalitis, but the effect in inflammatory bowel disease has not yet been demonstrated. In severe combined immunodeficient (SCID) mice, adoptively transferred CD4(+) CD25(-) T cells repopulate the lymphoid tissues and lead to development of chronic colitis characterized by CD4(+) T-cell proliferation against enterobacterial extract in vitro. In this model, we adoptively transferred in-vitro-generated bone-marrow-derived DCs exposed to interleukin-10 (IL-10) and an enterobacterial extract. We show that these cells are CD11c positive with intermediate expression of CD40, CD80 and CD86 and have a diminished secretion of IL-6, IL-12 p40/70, tumour necrosis factor-alpha and keratinocyte-derived chemokine (KC) compared to DCs treated with enterobacterial extract alone. In vivo, these cells prevented weight loss in SCID mice adoptively transferred with CD4(+) CD25(-) T cells, resulted in a lower histopathology colitis score and tended to result in higher serum levels of IL-1alpha, IL-10, IL-12, IL-13, IL-17, KC and monokine induced by interferon-gamma (MIG). These data underscore the potential of using immunomodulatory DCs to control inflammatory bowel disease and demonstrate its potential use in future human therapeutic settings.

Characterization of monocyte-derived dendritic cells maturated with IFN-alpha

Dendritic cells (DC) are promising candidates for cancer immunotherapy. These cells can be generated from peripheral blood monocytes cultured with granulocyte macrophage-colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). In order to obtain full functional capacity, maturation is required, but the most potent reagents such as LPS or polyriboinosinic polyribocytidylic acid (Poly I:C) are not approved for clinical use. We tested the ability of type I interferon (IFN) to induce such maturation. We found that 24-h IFN-alpha co-culture of day 7 monocyte-derived DC generated with GM-CSF and IL-4 induces increased numbers of DC positive for CD54 and CD40 together with the co-stimulatory molecule CD80 but not the activation marker CD83. Also, IFN-alpha maturation leads to an increase in IP-10 and MCP-1 chemokine secretion, but only a minor increase in IL-12p40 secretion. In line with this, maturation with IFN-alpha has only a small effect on induction of autologous T-cell stimulatory capacity of the DC. However, an increase in DC allogeneic T-cell stimulatory capacity was observed. These data suggest that IFN-alpha has a potential as a maturation agent used in DC-based cancer vaccine trials, but not as a single reagent.

Regulatory T cells in experimental colitis

Induction and maintenance of peripheral tolerance are important mechanisms to maintain the balance of the immune system. Growing evidence indicates that dysregulation of mucosal T cell responses may lead to loss of tolerance to commensal flora and to the development of inflammatory bowel diseases (IBD). Many studies suggest that active suppression of enteroantigen reactive cells mediated by regulatory T cells contributes to the maintenance of natural intestinal immune homeostasis. The use of the multiple animal models has not only improved our understanding of IBD, but also contributed to new suggestions of treatment strategies involving the use of regulatory T cells. The present review summarizes our current knowledge of regulatory T cells and their involvement in experimental IBD. The well-characterized SCID T cell transfer model and the naturally occurring regulatory CD4+CD25+ T cells are highlighted.

Phenotypic and functional characterization of clinical grade dendritic cells generated from patients with advanced breast cancer for therapeutic vaccination

Dendritic cells (DC) are promising candidates for cancer immunotherapy. However, it is not known whether in vitro-generated monocyte-derived DC from cancer patients are altered compared with DC from healthy donors. In a clinical phase I/II study, monocyte-derived DC were generated in vitro utilizing granulocyte macrophage colony-stimulating factor and rh-interleukin-4 (IL-4) and used for cancer immunotherapy. In this study, we tested the effect of various maturation cocktails and performed a comparative evaluation of the DC phenotype and functional characteristics. Polyriboinosinic polyribocytidylic acid (Poly I:C) + tumour necrosis factor-alpha (TNF-alpha) induced significant IL-12 p70 secretion, which was increased after addition of a decoy IL-10 receptor. The lymph node homing chemokine receptor CCR-7 expression was induced by TNF-alpha + IL-1beta + IL-6 + prostaglandin E2 but was not induced by Poly I:C + TNF-alpha. In general, DC from patients had an intermediate maturity phenotype with a significantly higher expression of CD40 and CD54 compared with healthy donors. In vitro analyses showed an unimpaired capacity of the patient-derived DC for antigen-specific (cytomegalovirus, tetanus and keyhole limpet haemocyanin) T-cell stimulation, whereas the allostimulatory capacity of patient-derived DC was significantly decreased. These data suggest that patient-derived DC are more differentiated but are less sensitive to maturation-inducing agents than DC obtained from healthy individuals.

Method for patterning stretched DNA molecules on mica surfaces by soft lithography

Lambda DNA was stretched and patterned on mica surface using soft lithography. A highly diluted solution of amino propyl trimethoxy silane in hexane was deposited on a line patterned polydimethylsiloxane (PDMS) stamp. The functionalized stamp was then used to pick up DNA by molecular combing while the line patterns are parallel to the liquid surface. The stamp was then microcontact printed on freshly cleaved mica. We successfully obtained stretched DNA pattern on mica surface. DNA was found to be stretched in patterns perpendicular to those carved on the stamp. The stretched DNA population was large enough to be used for molecular biology mapping studies. Furthermore, the possibility of locating stretched DNA molecules in the desired position by stamping makes this method a good candidate for assembling non-semiconductor molecular devices.

Immunobiological effects of glucosamine in vitro

Glucosamine (GlcN) and N-acetyl-d-glucosamine (GlcNAc) were assayed in vitro for their effects on proliferation, cytotoxicity and cytokine secretion in primary and secondary mixed lymphocyte cultures (MLCs). In addition, we studied the effect of GlcN and GlcNAc on the proliferation of purified CD4+ T cells exposed to immobilized anti-CD3 antibody. The present data show that GlcN, but not GlcNAc, inhibits CD4+ T-cell proliferation, the generation of alloreactive cytotoxic T lymphocytes (CTLs) and the secretion of interferon-gamma (IFN-gamma) and interleukin-5 (IL-5) in primary MLC. In secondary T helper-2 (Th2)-polarized MLC, GlcN, but not GlcNAc, inhibits IL-4 and IL-5 secretion, whereas no effect was found on IFN-gamma secretion in Th1-polarized MLC. Dendritic cells treated with GlcN showed a 75-80% decreased capacity for antigen cross-presentation and allostimulation. In cellular bioassays, GlcN was shown to inhibit the stimulatory activity of IL-4 and IL-2, as well as the cytotoxic activity of tumour necrosis factor-alpha (TNF-alpha). In conclusion, GlcN suppresses unprimed T-cell responses by interfering with antigen-presenting cell functions and by a direct inhibitory effect on T-cell proliferation. In addition, GlcN inhibits the secretion of cytokines in antigen-stimulated unprimed T cells and primed Th2-polarized cells.

Method for stretching DNA molecules on mica surface in one direction for AFM imaging

An efficient method was developed to stretch DNA molecules on an atomically flat surface for AFM imaging. This method involves anchoring DNA molecules from their 5' ends to amino silanized mica surfaces. N-Succinimidyl6-[3'-(2-pyridyldithio) propionamido]hexanoate (LC-SPDP), a heterobifunctional cross-linker with a flexible spacer arm was used for this purpose. The immobilization process was carried out by introducing a thiol group to the 5' end of DNA by PCR. Thiolated molecules were then reacted with the cross linker to conjugate with its 2-pyridyl disulphide group via sulfhydryl exchange. The resulting complex was deposited on amino silanized mica where NHS-ester moiety of the cross linker reacted with the primary amino group on the surface. Samples were washed by a current of water and dried by an air jet in one direction parallel to the surface. DNA molecules were shown to be fully stretched in one direction on imaging them by AFM.

CD4+ T regulatory cells from the colonic lamina propria of normal mice inhibit proliferation of enterobacteria-reactive, disease-inducing Th1-cells from scid mice with colitis

Adoptive transfer of CD4+ T cells into scid mice leads to a chronic colitis in the recipients. The transferred CD4+ T cells accumulate in the intestinal lamina propria (LP), express an activated Th1 phenotype and proliferate vigorously when exposed ex vivo to enteric bacterial antigens. As LP CD4+ T cells from normal BALB/c mice do not respond to enteric bacterial antigens, we have investigated whether colonic LP-derived CD4+ T cells from normal mice suppress the antibacterial response of CD4+ T cells from scid mice with colitis. LP-derived CD4+ T cells cocultured with bone marrow-derived dendritic cells effectively suppress the antibacterial proliferative response of CD4+ T cells from scid mice with colitis. The majority of these LP T-reg cells display a nonactivated phenotype and suppression is independent of antigen exposure, is partly mediated by soluble factor(s) different from IL-10 and TGF-beta, and is not prevented by the addition of high doses of IL-2 to the assay culture. Functionally and phenotypically the T-reg cells of the present study differ from previously described subsets of T-reg cells. The presence of T cells with a regulatory potential in the normal colonic mucosa suggests a role for these cells in the maintenance of local immune homeostasis of the gut.

Patterning DNA on microm scale on mica

Double-stranded DNA molecules were patterned by selective adsorption to aminosilane patterns on mica surfaces. Line patterns with 10 microm spacing were made by photolithography and transferred to a polymer stamp. The stamp was then used for applying aminosilane molecules by microcontact-printing technique on mica substrates. We applied DNA in Tris-EDTA (TE) buffer solution on the patterned substrate, and incubated it for 5 min at room temperature. The sample was then rinsed with pure water, and dried with nitrogen gas. Tapping mode force microscopy showed that DNA was adsorbed selectively on the aminosilanized parts of the mica substrate. We also tried to bridge two aluminum electrodes with DNA using AC electrophoresis.

Method for orienting DNA molecules on mica surfaces in one direction for atomic force microscopy imaging

An efficient method was developed to stretch DNA molecules on an atomically flat surface for AFM imaging. This method involves anchoring DNA molecules from their 5' ends to amino silanized mica surfaces. N-Succinimidyl6-[3'-(2-pyridyldithio) propionamido]hexanoate (LC-SPDP), a heterobifunctional cross-linker with a flexible spacer arm was used for this purpose. Immobilization was carried out by introducing a thiol group to the 5' end of DNA by PCR. Thiolated molecules were then reacted with the cross linker to conjugate with its 2-pyridyl disulphide group via sulfhydryl exchange. The resulting complex was deposited on amino silanized mica where NHS-ester moiety of the cross linker reacted with the primary amino group on the surface. Samples were washed by a current of water and dried by an air jet in one direction parallel to the surface. DNA molecules were fully stretched in one direction on imaging them by AFM.

Radically altered T cell receptor signaling in glycopeptide-specific T cell hybridoma induced by antigen with minimal differences in the glycan group

A T cell hybridoma raised against the synthetic glycopeptide T(72)(Tn) was used to study whether the initial TCR signaling events are markedly different when the hybridoma is stimulated with glycopeptides closely related to the cognate glycopeptide antigen. T(72)(Tn) has an alpha-D-GalNAc group O-linked to the central threonine in the decapeptide VITAFTEGLK, and the hybridoma is known to be highly specific for this carbohydrate group. T(72)(Tn)-pulsed APC induced tyrosine phosphorylation of the TCR-zeta 21- and 23-kDa proteins and the downstream p42/44 MAP kinase and strong IL-2 secretion. APC pulsed with T(72)(alpha-D-GlcNAc), which differs from T(72)(Tn) solely by the orientation of a hydroxy group in the carbohydrate structure, completely failed to induce detectable tyrosine phosphorylation and IL-2 secretion. APC pulsed with S(72)(Tn), which differs from T(72)(Tn) by not having a methyl group in the serine amino acid side chain to which the glycan is attached, induced partial tyrosine phosphorylation of the TCR-zeta 21-kDa protein, no tyrosine phosphorylation of the MAP kinases and no IL-2 production. Molecular modeling of the MHC/glycopeptide complex revealed that the dramatic difference between the stimulatory power of T(72)(Tn) and T(72)(alpha-D-GlcNAc) is mainly due to very small differences in the TCR exposed carbohydrate structure.

Accumulation of plant galactolipid affects cell morphology of Escherichia coli

Monogalactosyldiacylglycerol (MGDG) is a major constituent of thylakoid membrane in chloroplasts. Therefore, it is considered to have an important role in the maintenance of the complicated structure of the thylakoid membrane. We have succeeded in cloning the enzyme for MGDG synthesis and overexpressed it in Escherichia coli. In this study we analyzed the morphology of the E. coli harboring the gene. The fatty acid composition of its membrane lipids did not differ between the wild type and transformant, except for the appearance of MGDG. However, transformant cells appeared to be elongated. DAPI staining revealed the entire intracellular region of filamentous cells to be stained; therefore, the elongation of the cells is probably due to a defect in cell division. Atomic force microscopy revealed that the transformant had a smooth but scratched surface. It was concluded that the excessive accumulation of a non-bilayer lipid, MGDG, interfered with the translocation of proteins across the plasma membrane, including those for cell division.

Mapping cell wall polysaccharides of living microbial cells using atomic force microscopy

Functionalized atomic force microscope tips were used to sense specific forces of interaction between ligand-receptor pairs and to map the positions of polysaccharides on a living microbial cell surface. Gold-coated tips were functionalized with concanavalin A using a cross-linker with a spacer arm of 15.6 A. It was possible to measure the binding force between concanavalin A and mannan polymers on the yeast (Saccharomyces cerevisiae) cell surface. This force ranged from 75 to 200 pN. The shape of the force curve indicated that the polymers were pulled away from the cell surface for a fairly long distance that sometimes reached several hundred nanometres. The distribution of mannan on the cell surface was mapped by carrying out the force measurement in the force volume mode of atomic force microscopy (AFM). During the measurement, the maximum cantilever deflection after contact between the tip and the sample was kept constant at 10 nm using trigger mode to keep the pressing force on the sample surface as gently as possible at a force of 180 pN. This regime was used to minimize the non-specific adhesion between the tip and the cell surface. Specific molecular recognition events took place on specific areas of the cell surface that could be interpreted as reflecting a non-uniform distribution of mannan on the cell surface.

Comparative study between sonography, pathology and UGP in women with perimenopausal bleeding

Adenocarcinoma is the commonest primary malignancy encountered in the endometrium. Adenomatous hyperplasia represents an important precancerous endometrial lesion. In this study, different techniques have been applied in a trial to early detect endometrial carcinoma and to distinguish between hyperplasia with minimal and high risk of progression to endometrial adenocarcinoma. Eighty women were included in this study and classified into 4 groups: 10 with adenocarcinoma, 28 with simple hyperplasia, 12 with hyperplasia with atypia and 30 normal healthy women. All individuals were subjected to Doppler endovaginal ultrasonography (EVS) for endometrial thickness and uterine artery resistance index (RI). Endometrial biopsy was taken for histopathological examination and DNA analysis. 24-hr urine was collected for the estimation of UGP by ELISA using reagents supplied by Ciba Corning Diagnostica, Alameda, CA, USA (Triton UGP-EIA). On referring to histopathological findings, no single parameter was seen to be specific and sensitive enough to differentiate between benign and malignant endometrial lesions. Doppler endovaginal ultrasonography could detect 76% of endometrial abnormalities. DNA ploidy and UGP showed equal sensitivity rate (60%) in endometrial carcinoma but DNA ploidy was more specific than UGP (0% and 10% false positivity in benign endometrial diseases respectively.

UGP in urogenital disorders: Egyptian experience

UGP (Urinary gonadotropin peptide) also know as urinary gonadotropin fragment (UGF) or the beta-core of hCG (c beta hCG), was identified as a peptide with a molecular weight of 10.5 kD, having the same amino acid sequence as the core section of the beta-subunit of human chorionic gonadotropin. UGP has been found in normal pregnancy urine as well as in the urine of patients with gestational trophoblastic and non-trophoblastic malignancies. The aim of the present work was to investigate the clinical value of UGP in Egyptian patients with urogenital disorders. The study included 793 cases (462 males and 331 females) classified into 5 groups: 277 with bladder cancer, 121 with benign urinary tract disorders, 27 with different gynecological malignancies, 53 with benign gynecological disease and 315 apparently healthy individuals as a control group. The normal females included 88 premenopausal and 71 postmenopausal women. UGP was determined in 24- hour urine samples from all cases, and in morning urine samples from 151 subjects by ELISA technique using the reagents supplied by Ciba Corning Diagnostics, CA, USA (Triton UGP - EIA). The results of this study revealed significant elevation of UGP in cancer patients when compared to either normal controls or patients with benign diseases. Females in the control and benign diseases groups expressed higher UGP values than males and UGP in postmenopausal women was significantly elevated when compared to premenopausal control females. A a tumor marker, UGP was more sensitive and more specific in bladder than in gynecological cancer. A significant correlation (r = 0.934) was obtained between UGP levels in 24-hr and morning urine samples.

Method for immobilizing microbial cells on gel surface for dynamic AFM studies

The processes of cell growth and budding of the yeast cells Saccharomyces cerevisiae, which were gently immobilized on 3% agar and submerged in culture medium, were successfully imaged with an atomic force microscope for 6-7 h. Similar experiments on chemically fixed cells did not detect any appreciable change in their appearance except in a few scannings at the very beginning, indicating that the dissolution of agar and/or scraping of its surface by the scanning tip, if any, did not significantly interfere with the images taken thereafter. The increment in the height of many of the untreated cells, accompanied by their lateral enlargement, was taken as an indication of successful imaging of the growth process of yeast cells, together with an image of a growing daughter cell attached to its mother cell.

Vector competence of autogenous and anautogenous Culex pipiens mosquitoes for Wuchereria bancrofti

Vector competence of autogenous and anautogenous Culex pipiens; derived from North Sinai Governorate, Egypt, for the human filaria parasite Wuchereria bancrofti was studied. After feeding on the same microfilaremic volunteers both biotypes were readily infected with the parasite (infection rates > 80%) and supported its development to the infective stage within 11 - 12 days. Infective rates of both autogenous and anautogenous mosquitoes were similar (> 95%). However, autogenous Cx. pipiens developed significantly less number of infective stage larvae (4.7 +/- 1.4 L3 / female) than did anautogenous siblings (6.7 +/- 3.6 L3 / female) (P < 0.05). Moreover, autogenous females were observed to contain twice the number of L3 larvae in the thoracic muscles and less larvae in the head region compared to autogenous counterparts. Vector competence characteristics of Cx. pipiens derived from a filariasis endemic area in Qalubiya Governorate were similar to those of anautogenous mosquitoes of North Sinai. These findings indicate that autogenous Cx. pipiens may be less efficient vector of W. bancrofti in endemic areas of Egypt.

Percutaneous ethanol injection for the treatment of symptomatic cystic metastases from ovarian carcinoma. Work in progress

Two patients with symptomatic cystic metastases from ovarian epithelial carcinoma underwent ultrasound (US)-guided percutaneous aspiration and temporary injection of 99% ethanol into the cyst. In the first case, the patient initially underwent surgical resection of the mass and received systemic chemotherapy, but the cyst recurred 2 months later. Percutaneous aspiration and ethanol sclerotherapy were performed twice in the second case; fluid reaccumulated 2 months after the initial procedure. No side effects occurred. During the follow-up period (8 months in the first case and 4 months in the second), no clinical recurrence of the initial symptoms was noted. At the end of that period, a recurrent but asymptomatic cystic lesion was revealed at US examination in the first case. In the second case, a minimal asymptomatic residual collection was depicted with computed tomography. The results indicate that this technique should be considered in patients with symptomatic cystic metastases from ovarian carcinoma and may have potential benefit in the palliative treatment of such lesions.

Preoperative segmental localization of hepatic metastases: utility of three-dimensional CT during arterial portography

To evaluate the accuracy of a fast three-dimensional (3D) reconstruction technique in determining the segmental location of hepatic metastases, 14 patients (40 metastases) were prospectively investigated before surgery with dynamic two-dimensional (2D) computed tomography during sequential arterial portography (CTAP). All patients underwent subsequent hepatic tumor resection within 4 days. After computer-generated mapping of hepatic venous structures with high attenuation and metastases with low attenuation, 3D reconstruction was performed. Thirty-six of the 40 lesions (90%) were detected with 2D and 3D CTAP. The accuracy in determining the segmental location of hepatic metastases was 78% (28 of the 36 metastases) for 2D CTAP and 94% (34 of the 36 metastases) for 3D CTAP. The difference in localization rates between 2D CTAP and 3D CTAP was statistically significant. The 3D CTAP technique provides vital data unattainable with other imaging modalities that improve the preoperative assessment of the resectability of hepatic metastases and allows planning a safer surgical approach.