The perspectives of biomarker-based electrochemical immunosensors, artificial intelligence and the Internet of Medical Things toward COVID-19 diagnosis and management

The World Health Organization (WHO) has declared the COVID-19 an international health emergency due to the severity of infection progression, which became more severe due to its continuous spread globally and the unavailability of appropriate therapy and diagnostics systems. Thus, there is a need for efficient devices to detect SARS-CoV-2 infection at an early stage. Nowadays, the reverse transcription polymerase chain reaction (RT-PCR) technique is being applied for detecting this virus around the globe; however, factors such as stringent expertise, long diagnostic times, invasive and painful screening, and high costs have restricted the use of RT-PCR methods for rapid diagnostics. Therefore, the development of cost-effective, portable, sensitive, prompt and selective sensing systems to detect SARS-CoV-2 in biofluids at fM/pM/nM concentrations would be a breakthrough in diagnostics. Immunosensors that show increased specificity and sensitivity are considerably fast and do not imply costly reagents or instruments, reducing the cost for COVID-19 detection. The current developments in immunosensors perhaps signify the most significant opportunity for a rapid assay to detect COVID-19, without the need of highly skilled professionals and specialized tools to interpret results. Artificial intelligence (AI) and the Internet of Medical Things (IoMT) can also be equipped with this immunosensing approach to investigate useful networking through database management, sharing, and analytics to prevent and manage COVID-19. Herein, we represent the collective concepts of biomarker-based immunosensors along with AI and IoMT as smart sensing strategies with bioinformatics approach to monitor non-invasive early stage SARS-CoV-2 development, with fast point-of-care (POC) diagnostics as the crucial goal. This approach should be implemented quickly and verified practicality for clinical samples before being set in the present times for mass-diagnostic research.

The effect of COVID-19 on general anaesthesia rates for caesarean section. A cross-sectional analysis of six hospitals in the north-west of England

At the onset of the global pandemic of COVID-19 (SARS-CoV-2), guidelines recommended using regional anaesthesia for caesarean section in preference to general anaesthesia. National figures from the UK suggest that 8.75% of over 170,000 caesarean sections are performed under general anaesthetic. We explored whether general anaesthesia rates for caesarean section changed during the peak of the pandemic across six maternity units in the north-west of England. We analysed anaesthetic information for 2480 caesarean sections across six maternity units from 1 April to 1 July 2020 (during the pandemic) and compared this information with data from 2555 caesarean sections performed at the same hospitals over a similar period in 2019. Primary outcome was change in general anaesthesia rate for caesarean section. Secondary outcomes included overall caesarean section rates, obstetric indications for caesarean section and regional to general anaesthesia conversion rates. A significant reduction (7.7 to 3.7%, p < 0.0001) in general anaesthetic rates, risk ratio (95%CI) 0.50 (0.39-0.93), was noted across hospitals during the pandemic. Regional to general anaesthesia conversion rates reduced (1.7 to 0.8%, p = 0.012), risk ratio (95%CI) 0.50 (0.29-0.86). Obstetric indications for caesarean sections did not change (p = 0.17) while the overall caesarean section rate increased (28.3 to 29.7%), risk ratio (95%CI) 1.02 (1.00-1.04), p = 0.052. Our analysis shows that general anaesthesia rates for caesarean section declined during the peak of the pandemic. Anaesthetic decision-making, recommendations from anaesthetic guidelines and presence of an on-site anaesthetic consultant in the delivery suite seem to be the key factors that influenced this decline.

Evaluation of MTBDRsl for detecting resistance in Mycobacterium tuberculosis to second-line drugs

SETTING: Patients with presumed multidrug-resistant tuberculosis (MDR-TB) and undergoing MDR-TB treatment from Rajasthan, India.OBJECTIVE: To compare the GenoType^® MTBDRsl v.1.0 (MTBDRsl) assay capacity to detect resistance to ofloxacin, amikacin, capreomycin, kanamycin and ethambutol in Mycobacterium tuberculosis with phenotypic drug susceptibility testing (DST) using MGIT^™960™ in sputum samples and isolates.DESIGN: Fifty-three smear-positive sputum samples were tested directly by MTBDRsl and 205 MDR-TB isolates were processed using MTBDRsl and DST for five drugs on MGIT960. DNA sequencing was performed in isolates with discordance in the results between the two methods for the gyrA, gyrB and rrs genes.RESULT: Sensitivity and specificity of MTBDRsl was found to be respectively 93.1% and 100% for fluoroquinoline, respectively 75-78% and 100% for aminoglycosides/cyclopeptides, respectively 70% and 92% for ethambutol and respectively 92.3% and 100% for extensively drug-resistant (XDR) TB detection. On sequencing eight discordant isolates for quinolones, mutations were seen in 12.5% of the gyrB gene and among 20 discordant isolates for aminoglycosides/cyclopeptides in the rrs gene in 15% isolates. The turnaround time was 2 days for MTBDRsl vs. 10 days for MGIT960.CONCLUSIONS: MTBDRsl can be used as an initial rapid test for detecting XDR-TB, resistance to quinolones and aminogycosides/cyclopeptides in smear-positive sputum samples.

17 Improving Frailty Identification and Comprehensive Geriatric Assessment (CGA) Completion on the Wards

Introduction

The Comprehensive Geriatric Assessment (CGA) is known to deliver substantial and measurable health improvements to frail older people, including increased independence and a reduction in mortality.1 The Clinical Frailty Scale (CFS) can detect older adults at higher risk of complicated course and longer hospital stay.2 Despite the known benefits, previous audits has shown poor documentation on geriatric wards at Southend Hospital. Therefore, we devised a Quality Improvement Project to improve the uptake of both these.

Methods

A total of two Plan Do Study Act (PDSA) cycles were completed where CGA completion and CFS documentation was audited. Each cycle lasted two weeks (25 patients). Qualitative feedback was obtained from the members of multidisciplinary team to aid improvements. The baseline audit was based on the introduction of a 2-page ward proforma for all new patients. The first intervention was an improved 2-page ward-proforma. The second intervention was a single page ward-proforma.

Results

Originally, 40% of new patients admitted onto the ward had a CGA assessment and CFS score. After the first intervention, 79% (19) patients had a CFS score and a CGA assessment. 21% had a full CGA completed and 58% had partial CGA. Feedback included wanting a single page proforma to increase uptake. Questions needed to be more unambiguous and more tick boxes. After the second intervention 100% (25) patients had a CFS score and a CGA assessment. 40% (10) had a full CGA completed and 60% (15) had a partial CGA. Feedback include incorporating the ward round documentation to avoid repetition.

Conclusions

The results show that by using a focused, concise and user-friendly proforma, uptake of the Comprehensive Geriatric Assessment and Clinical Frailty Scale can be significantly increased, bringing substantial and measurable health improvements to frail older people admitted to elderly care wards.

References

1. Welsh TJ, Gordon AL, Gladman JR. Int J Clin Pract. 2014;68(3):290–293.

2. Juma S, Taabazuing MM, Montero-Odasso M. Can Geriatr J. 2016;19(2):34–39.

P3730Left atrial appendage perimeter measurement by cardiac CT is superior to transesophageal echocardiography for Watchman device sizing

Background

Left atrial appendage occlusion with Watchman device traditionally relies on accurate left atrial appendage (LAA) ostium diameter measurement by 2D or 3D transesophageal echocardiogram (TEE). Alternate methods of ostium measurement including area-derived diameter and perimeter-derived diameter using cardiac computed tomography (CT) have been proposed.

Purpose

We aim to use CT technology with an advanced medical imaging application to measure LAA ostium perimeter for improved pre-procedural device sizing.

Methods

We performed a retrospective analysis of 92 patients with atrial fibrillation (Afib) who underwent Watchman implantation with pre-procedural TEE and cardiac CT between May 2015 and December 2018. LAA characteristics including ostial or landing zone perimeter, minimum and maximum diameters were acquired utilizing 3mensio Structural Heart Imaging Program. Proposed Watchman device size was estimated utilizing ostium perimeter by CT and compared to the current standard utilizing ostium diameter by 2D-TEE. Both measurements were then compared to actual implanted Watchman device size which met the P.A.S.S. criteria of position, anchor, size and seal.

Results

Watchman device sizing based on novel LAA landing zone perimeter size by CT had a very high correlation with the actual implanted Watchman size (Pearson coefficient r=0.94, p<0.001). Traditional TEE based Watchman sizing only had a modest correlation with the implanted Watchman size (Pearson coefficient r=0.66, p<0.001). CT predicted Watchman size had a significantly higher agreement compared to current standard TEE based sizing (93.4% vs 47.8%), inter-rater agreement was very high for CT based Watchman sizing compared to current standard TEE based sizing (Cohen's kappa = 0.91 vs Cohen's kappa = 0.32, p<0.001, p<0.001 respectively). Bland-Altman analysis also showed better correlation with CT based sizing compared to TEE (see Figure 1).

Figure 1

Conclusion

CT LAA perimeter sizing is superior to the current standard TEE based Watchman sizing. Larger, multi-center studies may be necessary to further validate our results.

The psoriasis-protective TYK2 I684S variant impairs IL-12 stimulated pSTAT4 response in skin-homing CD4+ and CD8+ memory T-cells

Tyrosine kinase 2 (TYK2) belongs to the Janus kinase (JAK) family of tyrosine kinases, which transmit signals from activated cytokine receptors. GWAS have consistently implicated TYK2 in psoriasis susceptibility. We performed an in-depth association analysis of TYK2 using GWAS and resequencing data. Strong genetic association of three nonsynonymous variants in the exonic regions of the TYK2 gene (rs34536443, rs12720356, and rs2304256) were found. rs12720356 encoding I684S is predicted to be deleterious based on its location in the pseudokinase domain. We analyzed PBMCs from 29 individuals representing the haplotypes containing each of the significantly associated signals. STAT4 phosphorylation was evaluated by phospho-flow cytometry after CD3/CD28 activation of cells followed by IL-12 stimulation. Individuals carrying the protective I684S variant manifested significantly reduced p-STAT4 levels in CD4 + CD25 + CD45RO+ (mean Stimulation Index (S.I.) 48.08, n = 10) and CD8 + CD25 + CD45RO + cells (S.I. 55.71, n = 10), compared to controls homozygous for the ancestral haplotype (S.I. 68.19, n = 10 (p = 0.002) and 76.76 n = 10 (p = 0.0008) respectively). Reduced p-STAT4 levels were also observed in skin-homing, cutaneous lymphocyte associated antigen (CLA)-positive CD4 and CD8 cells from I684S carriers. No significant changes in p-STAT4 for the psoriasis-associated variant rs34536443 was found. These data establish the functional significance of the TYK2 I684S variant in psoriasis susceptibility.

Clinical and Molecular Phenotypes of Low-Penetrance Variants of NLRP3: Diagnostic and Therapeutic Challenges

OBJECTIVE

Cryopyrin-associated periodic syndromes (CAPS) result from gain-of-function mutations in the NLRP3 gene, which causes excessive release of interleukin-1β (IL-1β) and systemic inflammation. While pathogenetic NLRP3 variant phenotypes are well-characterized, low-penetrance NLRP3 variants represent a significant clinical challenge. The aims of this study were to determine the clinical phenotype, the in vitro biologic phenotype, and the effect of anti-IL-1 treatment in patients with low-penetrance NLRP3 variants.

METHODS

A multicenter study of consecutive symptomatic patients with low-penetrance NLRP3 variants recruited from 7 centers between May 2012 and May 2013 was performed. The observed findings were transferred into a study database, from which they were extracted for analysis. Controls were patients with a known pathogenetic NLRP3 variant. Clinical presentation and CAPS markers of inflammation were captured. Functional assays of inflammasome activation, including caspase 1 activity, NF-κB release, cell death, and IL-1β release, were performed. Treatment effects of IL-1 were determined. Comparisons between low-penetrance and pathogenetic NLRP3 variants were performed.

RESULTS

The study included 45 patients, 21 of which were female (47%); 26 of the patients (58%) were children. NLRP3 low-penetrance variants identified in the patients were Q703K (n = 19), R488K (n = 6), and V198M (n = 20). In the controls, 28 had pathogenetic NLRP3 variants. Patients with low-penetrance NLRP3 variants had significantly more fever (76%) and gastrointestinal symptoms (73%); eye disease, hearing loss, and renal involvement were less common. Functional inflammasome testing identified an intermediate phenotype in low-penetrance NLRP3 variants as compared to wild-type and pathogenetic NLRP3 variants. All treated patients responded to IL-1 inhibition, with complete response documented in 50% of patients.

CONCLUSION

Patients with low-penetrance NLRP3 variants display a distinct clinical phenotype and an intermediate biologic phenotype, including IL-1β and non-IL-1β-mediated inflammatory pathway activation.

Pancreatic polypeptide and its central Y4 receptors are essential for cued fear extinction and permanent suppression of fear

Background and purpose

Avoiding danger and finding food are closely related behaviours that are essential for surviving in a natural environment. Growing evidence supports an important role of gut‐brain peptides in modulating energy homeostasis and emotional‐affective behaviour. For instance, postprandial release of pancreatic polypeptide (PP) reduced food intake and altered stress‐induced motor activity and anxiety by activating central Y₄ receptors.

Experimental approach

We characterized [K³⁰(PEG2)]hPP_2‐36 as long‐acting Y₄ receptor agonist and injected it peripherally into wildtype and Y₄ receptor knockout (Y4KO) C57Bl/6NCrl mice to investigate the role of Y₄ receptors in fear conditioning. Extinction and relapse after extinction was measured by spontaneous recovery and renewal.

Key results

The Y4KO mice showed impaired cued and context fear extinction without affecting acquisition, consolidation or recall of fear. Correspondingly, peripheral injection of [K³⁰(PEG2)]hPP_2‐36 facilitated extinction learning upon fasting, an effect that was long‐lasting and generalized. Furthermore, peripherally applied [K³⁰(PEG2)]hPP_2‐36 before extinction inhibited the activation of orexin‐expressing neurons in the lateral hypothalamus in WT, but not in Y4KO mice.

Conclusions and implications

Our findings suggests suppression of excessive arousal as a possible mechanism for the extinction‐promoting effect of central Y₄ receptors and provide strong evidence that fear extinction requires integration of vegetative stimuli with cortical and subcortical information, a process crucially depending on Y₄ receptors. Importantly, in the lateral hypothalamus two peptide systems, PP and orexin, interact to generate an emotional response adapted to the current homeostatic state. Detailed investigations of feeding‐relevant genes may thus deliver multiple intervention points for treating anxiety‐related disorders.

The role of Neuropeptide Y in fear conditioning and extinction

While anxiety disorders are the brain disorders with the highest prevalence and constitute a major burden for society, a considerable number of affected people are still treated insufficiently. Thus, in an attempt to identify potential new anxiolytic drug targets, neuropeptides have gained considerable attention in recent years. Compared to classical neurotransmitters they often have a regionally restricted distribution and may bind to several distinct receptor subtypes. Neuropeptide Y (NPY) is a highly conserved neuropeptide that is specifically concentrated in limbic brain areas and signals via at least 5 different G-protein-coupled receptors. It is involved in a variety of physiological processes including the modulation of emotional-affective behaviors. An anxiolytic and stress-reducing property of NPY is supported by many preclinical studies. Whether NPY may also interact with processing of learned fear and fear extinction is comparatively unknown. However, this has considerable relevance since pathological, inappropriate and generalized fear expression and impaired fear extinction are hallmarks of human post-traumatic stress disorder and a major reason for its treatment-resistance. Recent evidence from different laboratories emphasizes a fear-reducing role of NPY, predominantly mediated by exogenous NPY acting on Y1 receptors. Since a reduction of fear expression was also observed in Y1 receptor knockout mice, other Y receptors may be equally important. By acting on Y2 receptors, NPY promotes fear extinction and generates a long-term suppression of fear, two important preconditions that could support cognitive behavioral therapies in human patients. A similar effect has been demonstrated for the closely related pancreatic polypeptide (PP) when acting on Y4 receptors. Preliminary evidence suggests that NPY modulates fear in particular by activation of Y1 and Y2 receptors in the basolateral and central amygdala, respectively. In the basolateral amygdala, NPY signaling activates inhibitory G protein-coupled inwardly-rectifying potassium channels or suppresses hyperpolarization-induced I(h) currents in a Y1 receptor-dependent fashion, favoring a general suppression of neuronal activity. A more complex situation has been described for the central extended amygdala, where NPY reduces the frequency of inhibitory and excitatory postsynaptic currents. In particular the inhibition of long-range central amygdala output neurons may result in a Y2 receptor-dependent suppression of fear. The role of NPY in processes of learned fear and fear extinction is, however, only beginning to emerge, and multiple questions regarding the relevance of endogenous NPY and different receptor subtypes remain elusive. Y2 receptors may be of particular interest for future studies, since they are the most prominent Y receptor subtype in the human brain and thus among the most promising therapeutic drug targets when translating preclinical evidence to potential new therapies for human anxiety disorders.

Structure and function of the amygdaloid NPY system: NPY Y2 receptors regulate excitatory and inhibitory synaptic transmission in the centromedial amygdala

The amygdala is essential for generating emotional-affective behaviors. It consists of several nuclei with highly selective, elaborate functions. In particular, the central extended amygdala, consisting of the central amygdala (CEA) and the bed nucleus of the stria terminalis (BNST) is an essential component actively controlling efferent connections to downstream effectors like hypothalamus and brain stem. Both, CEA and BNST contain high amounts of different neuropeptides that significantly contribute to synaptic transmission. Among these, neuropeptide Y (NPY) has emerged as an important anxiolytic and fear-reducing neuromodulator. Here, we characterized the expression, connectivity and electrophysiological function of NPY and Y2 receptors within the CEA. We identified several NPY-expressing neuronal populations, including somatostatin- and calretinin-expressing neurons. Furthermore, in the main intercalated nucleus, NPY is expressed primarily in dopamine D1 receptor-expressing neurons but also in interspersed somatostatin-expressing neurons. Interestingly, NPY neurons did not co-localize with the Y2 receptor. Retrograde tract tracing experiments revealed that NPY neurons reciprocally connect the CEA and BNST. Functionally, the Y2 receptor agonist PYY3-36, reduced both, inhibitory as well as excitatory synaptic transmission in the centromedial amygdala (CEm). However, we also provide evidence that lack of NPY or Y2 receptors results in increased GABA release specifically at inhibitory synapses in the CEm. Taken together, our findings suggest that NPY expressed by distinct populations of neurons can modulate afferent and efferent projections of the CEA via presynaptic Y2 receptors located at inhibitory and excitatory synapses.

NPY Y2 receptors in the central amygdala reduce cued but not contextual fear

The amygdala is fundamental for associative fear and extinction learning. Recently, also the central nucleus of the amygdala (CEA) has emerged as a site of plasticity actively controlling efferent connections to downstream effector brain areas. Although synaptic transmission is primarily mediated by glutamate and GABA, neuropeptides critically influence the overall response. While neuropeptide Y (NPY) acting via postsynaptic Y1 receptors exerts an important anxiolytic and fear-reducing action, the role of the predominantly presynaptic Y2 receptors is less defined. To investigate the role of Y2 receptors in the CEA we employed viral-vector mediated over-expression of the Y2 selective agonist NPY3-36 in fear conditioning and extinction experiments. NPY3-36 over-expression in the CEA resulted in reduced fear expression during fear acquisition and recall. Interestingly, this effect was blocked by intraperitoneal injection of a brain-penetrant Y2 receptor antagonist. Furthermore, over-expression of NPY3-36 in the CEA also reduced fear expression during fear extinction of CS-induced but not context-related fear. Again, fear extinction appeared delayed by peripheral injection of a Y2 receptor antagonist JNJ-31020028. Importantly, mice with over-expression of NPY3-36 in the CEA also displayed reduced spontaneous recovery and reinstatement, suggesting that Y2 receptor activation supports a permanent suppression of fear. Local deletion of Y2 receptors in the CEA, on the other hand, increased the expression of CS-induced freezing during fear recall and fear extinction. Thus, NPY inhibits fear learning and promotes cued extinction by reducing fear expression also via activation of presynaptic Y2 receptors on CEA neurons.

Genetic variations of NLRP1: susceptibility in psoriasis

BACKGROUND

NACHT, LRR and PYD domain-containing protein (NLRP)1 is part of the inflammasome multiprotein complex involved in the production of interleukin (IL)-1β and IL-18, two cytokines strongly implicated in psoriasis pathogenesis. Genetic variations in NLRP1 are associated with a predisposition for chronic inflammatory conditions.

OBJECTIVES

The aim of the study was to investigate the role of genetic variation in the NLRP1 inflammasome in psoriasis susceptibility.

MATERIAL AND METHODS

Four haplotype-tagging single-nucleotide polymorphisms (SNPs) (rs6502867, rs8079034, rs878329 and rs12150220) were investigated by TaqMan allelic discrimination in a patient sample comprising 1847 individuals from 478 families and 802 healthy controls.

RESULTS

Using the transmission disequilibrium test, a significant increase in the transmission of the NLRP1 rs8079034C and rs878329C alleles to patients with psoriasis was demonstrated (P = 0·006 and P = 0·033, respectively). Furthermore, homozygosity for the rs878329C allele correlated with a younger age of onset. We also observed an increase in the expression of NLRP1 mRNA in the peripheral blood cells of patients with psoriasis. This was accompanied by a higher level of circulating IL-18 and appeared to be associated with the rs878329C allele.

CONCLUSIONS

Our data support the involvement of NLRP1 and the NLRP1 inflammasome in psoriasis susceptibility and further support the role of innate immunity in psoriasis.

Potential contribution of monoamine oxidase a gene variants in ADHD and behavioral co-morbidities: scenario in eastern Indian probands

Attention deficit hyperactivity disorder (ADHD) is the most frequently diagnosed behavioral disorder in children with a high frequency of co-morbid conditions like conduct disorder (CD) and oppositional defiant disorder (ODD). These traits are controlled by neurotransmitters like dopamine, serotonin and norepinephrine. Monoamine oxidase A (MAOA), a mitochondrial enzyme involved in the degradation of amines, has been reported to be associated with aggression, impulsivity, depression, and mood changes. We hypothesized that MAOA can have a potential role in ADHD associated CD/ODD and analyzed 24 markers in a group of Indo-Caucasoid subjects. ADHD probands and controls (N = 150 each) matched for ethnicity and gender were recruited following the Diagnostic and Statistical Manual for Mental Disorders-IV. Appropriate scales were used for measuring CD and ODD traits. Markers were genotyped by PCR-based methods and data obtained analyzed using the Cocaphase program under UNPHASED. Only eight markers were found to be polymorphic. rs6323 "G" allele showed higher frequencies in ADHD (P = 0.0023), ADHD + CD (P = 0.03) and ADHD + ODD (P = 0.01) as compared to controls. Haplotype analysis revealed statistically significant difference for three haplotypes in ADHD cases (P < 0.02). Statistically significant differences were also noticed for haplotypes in ADHD + CD and ADHD + ODD cases (P < 0.01). LD analysis showed significant variation in different groups. Multidimensionality reduction analysis showed independent as well as interactive effects of markers. Genotypes showed correlation with behavioral problems in ADHD and ADHD + CD. We interpret that MAOA gene variants may contribute to the etiology of ADHD as well as associated co-morbid CD and ODD in this ethnic group.

Mitochondrial electron transport chain complexes, catalase and markers of oxidative stress in platelets of patients with severe aluminum phosphide poisoning

Aluminum phosphide (ALP), a widely used fumigant and rodenticide, leads to high mortality if ingested. Its toxicity is due to phosphine that is liberated when it comes in contact with moisture. The exact site or mechanism of action of phosphine is not known, although it is widely believed that it affects mitochondrial oxidative phosphorylation. Basic serum biochemical parameters, activity of mitochondrial complexes, antioxidant enzymes and parameters of oxidative stress were estimated in the platelets of 21 patients who developed severe poisoning following ALP ingestion. These parameters were compared with 32 healthy controls and with 22 patients with shock due to other causes (cardiogenic shock (11), septic shock (9) and hemorrhagic shock (2)). The serum levels of creatine kinase-muscle brain and lactate dehydrogenase were higher in patients poisoned with ALP, whereas a significant decrease was observed in the activities of mitochondrial complexes I, II and IV. The activity of catalase was lower but the activities of superoxide dismutase and glutathione peroxidase were unaffected in them. A significant increase in lipid peroxidation and protein carbonylation was observed, whereas total blood thiol levels were lower. In patients severely poisoned with ALP, not only cytochrome c oxidase but also other complexes are involved in mitochondrial electron transport, and enzymes are also inhibited.

NPY controls fear conditioning and fear extinction by combined action on Y₁ and Y₂ receptors

BACKGROUND AND PURPOSE

Neuropeptide Y (NPY) and its receptors have been implicated in the control of emotional-affective processing, but the mechanism is unclear. While it is increasingly evident that stimulation of Y₁ and inhibition of Y₂ receptors produce prominent anxiolytic and antidepressant effects, the contribution of the individual NPY receptor subtypes in the acquisition and extinction of learned fear are unknown.

EXPERIMENTAL APPROACH

Here we performed Pavlovian fear conditioning and extinction in NPY knockout (KO) and in NPY receptor KO mice.

KEY RESULTS

NPY KO mice display a dramatically accelerated acquisition of conditioned fear. Deletion of Y₁ receptors revealed only a moderately accelerated acquisition of conditioned fear, while lack of Y₂ receptors was without any effect on fear learning. However, the strong phenotype seen in NPY KO mice was reproduced in mice lacking both Y₁ and Y₂ receptors. In addition, NPY KO mice showed excessive recall of conditioned fear and impaired fear extinction. This behaviour was replicated only after deletion of both Y₁ and Y₂ receptors. In Y₁ receptor single KO mice, fear extinction was delayed and was unchanged in Y₂ receptor KO mice. Deletion of NPY and particularly Y₂ receptors resulted in a generalization of conditioned fear.

CONCLUSIONS AND IMPLICATIONS

Our data demonstrate that NPY delays the acquisition, reduces the expression of conditioned fear while promoting fear extinction. Although these effects appear to be primarily mediated by Y₁ receptors, the pronounced phenotype of Y₁Y₂ receptor double KO mice suggests a synergistic role of Y₂ receptors in fear acquisition and in fear extinction.

Bilateral symmetrical facial swelling owing to tuberculous gummas

Metastatic tuberculous abscesses and gummas are unusual forms of cutaneous tuberculosis. They result from haematogeneous spread of the mycobacterium from a primary focus during a period of impaired immunity. A 5-year-old boy is reported who presented with spinal tuberculosis and bilateral subcutaneous swelling of the cheeks owing to tuberculous gummas.

Prognostic value of FLT3 mutations among different cytogenetic subgroups in acute myeloid leukemia (AML)

7015

Background: Mutations of the FLT3 gene (in special internal tandem duplication -ITD) are common in normal karyotype AML (NK-AML) and are associated with shorter relapse free and overall survival (OS). The frequency of FLT3 mutations is lower in other cytogenetic subgroups and the impact on outcome is unclear. Methods: The records of patients (pts) with newly diagnosed AML (from 2003 to 2007) were reviewed. Pts were divided among three cytogenetic subgroups: Good-risk (t(8;21), Inv(16)/t(16;16)) Intermediate-Risk (Diploid,-Y) and Poor Risk (-5,-7, 11q abnormalities). FLT3 ITD and tyrosine kinase domain (TKD) mutations were determined on baseline DNA samples by a PCR based method with 1% sensitivity. Since the frequencies of FLT3 mutations were lower in good- and poor-risk subgroups, ITD/TKD mutations were considered together in the analysis, while in the intermediate risk group they were analyzed separately. Survival curves stratified by FLT3 mutation were estimated by Kaplan Meier plots and compared by logrank test. A Cox model was fit for OS, and non-significant variables were eliminated in a step-down fashion with a p- value cut-off of p = .10. Results: A total of 481 pts were included (65 pts=good risk, 272 pts=intermediate risk and 144 pts= poor risk). Prevalence of FLT3 mutations is shown in the Table. No difference was found in median OS between FLT3-mutated and FLT3- wild type pts in the good risk group (not reached (NR) vs NR, P = 0.57) nor in the poor risk group (55 vs 24 weeks, P = 0.44). In intermediate risk, OS was worse in FLT3-ITD positive pts (33 vs 89 weeks, P < 0.0001) but not in FLT3-TKD positive pts (77 vs 70 weeks, P = 0.89). In the Cox model, FLT3 mutations were prognostic for OS only in intermediate risk pts with FLT3-ITD (HR 2.63, P < 0.0001). Conclusions: In our cohort of pts, FLT3 mutations did not have a prognostic impact in AML with good and poor risk karyotype.

[Table: see text]

No significant financial relationships to disclose.

Chronic myeloid leukemia (CML) with e1a2 BCR-ABL fusion transcript type: Analysis of characteristics, outcomes, and prognostic significance

7030

Background: The most common BCR-ABL fusion transcripts in CML are e13a2 (b2a2) and e14a2 (b3a2). Rarely, other transcripts like e1a2 are seen. Currently, there is no published series of data on efficacy of imatinib or other tyrosine kinase inhibitors (TKIs) in CML with e1a2. Methods: We analyzed records of 1,292 CML patients treated with TKI at our institution between January 2000 and November 2008. Results: 14 CML patients with e1a2 transcripts were identified, 9 in chronic phase (CP), 1 in accelerated phase (AP), and 4 in blast phase (BP). Median age at diagnosis was 60 (range 28–86) years, median follow-up 39.5 (range 2–109) months. Of the 9 in CP, 3 received interferon and then imatinib after interferon failure, 6 received TKI as first-line therapy (5 imatinib, 1 nilotinib): 5 achieved CHR only, 1 CCyR, 1 MCyR, 1 PCyR, and 1 did not respond to imatinib. 5 patients (2 post-interferon failure - 1 in CHR, 1 in PCyR; 3 frontline imatinib - 1 in CHR, 1 in CCyR, 1 non-responder) progressed to advanced phases (3 myeloid BP, 1 lymphoid BP, 1 AP) at a median 48 (range 4–92) months after CML diagnosis; with only 1 alive and in CMR after allogeneic SCT. AP patient received various TKIs sequentially and achieved only CHR with disappearance of clonal evolution. BP patients received Hyper-CVAD+imatinib/dasatinib or idarubicin+Ara-C; 2 did not respond, 1 had CCyR lasting 12 months with Hyper-CVAD+Imatinib and 1 had CMR after allogeneic SCT lasting 2 months. In all 14 patients, cytogenetic responses lasted 1–9 months before being lost and none (except 2) achieved MMR or CMR on imatinib or other TKI therapy. Six patients (5 CP, 1 AP) were alive at a median 39 (range 2–85) months after initial diagnosis: 4 with CHR (2 on imatinib, 1 nilotinib, 1 bosutinib), 1 with MCyR on imatinib, and 1 with CMR after allogeneic SCT. Conclusions: CML with e1a2 BCR-ABL fusion transcripts is rare and is associated with an inferior outcome to therapy with TKI, with responses being usually short-lived. These patients need to be identified as high-risk patients and monitored closely for efficacy during therapy with TKI.

No significant financial relationships to disclose.

An animal model for studying endoscopic ultrasound changes of early chronic pancreatitis with histologic correlation: a pilot study

BACKGROUND AND STUDY AIMS

Due to the difficulty in obtaining pancreatic tissue for histology in humans, we developed an animal model for studying endoscopic ultrasound (EUS) changes of early chronic pancreatitis. This report on the animal model describes the serial changes of early chronic pancreatitis by EUS and correlates results with histology.

MATERIALS AND METHODS

Four 60 - 80-lb dogs were used in the study. Pancreatic EUS was performed to provide baseline images prior to any procedure. At laparotomy, a guide wire was passed into the pancreatic duct, and a 5-Fr pancreatic stent was introduced over the wire into the pancreatic duct. Animals were divided into two survival groups - 2 weeks and 4 weeks. In each group, EUS examination was performed under anesthesia to image the pancreas and then followed by euthanasia. Sequential pancreatic sections were taken from the head, body, and tail of the pancreas. EUS findings were correlated with histologic results with respect to degree of fibrosis, inflammation, and edema.

RESULTS

At baseline EUS, the pancreas appeared homogeneous with only a few echogenic septations and echogenic margins of the main pancreatic duct. At 2 and 4 weeks poststenting, EUS images showed the following changes: lobularity, hyper and hypoechoic foci, increased echogenic septations, visible pancreatic duct side branches, and irregular margins of the main pancreatic duct.

CONCLUSIONS

The dog model for chronic pancreatitis appears to be a promising method for studying sequential changes of chronic pancreatitis by EUS and correlating results with histology.

Radicular cyst associated with a deciduous molar: A case report with unusual clinical presentation

This article presents case report of a patient with radicular cyst associated with a primary molar with an unusual clinical presentation. The management comprised of enucleation of the cystic sac under general anesthesia.

Structural and functional analysis of a salt stress inducible gene encoding voltage dependent anion channel (VDAC) from pearl millet (Pennisetum glaucum)

We have cloned and characterized a gene encoding voltage-dependent anion channel from Pennisetum glaucum (PgVDAC). PgVDAC was identified while isolating genes that were differentially up-regulated following salt stress. The genomic organization of PgVDAC clone was well conserved compared to other plant VDAC genes in terms of number of introns, their position and phasing, however, the primary amino acid sequence of voltage dependent anion channel (VDAC) proteins did not show much conservation with other plant VDACs but their secondary and tertiary structures are well conserved as predicted by in silico structural and CD spectra analyses and results show it to be a typical membrane-spanning beta-barrel leading to the formation of pore in the membrane. The heterologous expression of PgVDAC protein in yeast strain lacking the endogenous mitochondrial VDAC gene could not functionally complement it as was also previously observed for the potato VDAC. Using real-time quantitative PCR analysis it was found that transcript expression profile of PgVDAC was quantitatively and kinetically up-regulated in response to salinity, desiccation, cold and exogenous application of salicylic acid (SA); however, there was no effect of exogenous application of abscisic acid (ABA) on its expression. Constitutive over-expression of PgVDAC appears to be deleterious in transgenic rice plant; however, low level of up-regulation imparted salinity stress adaptive response. A search for a more suitable inducible transgene system is currently under way to understand PgVDAC expression levels in plant development and its role in stress adaptation.

Virtual reality simulator for vitreoretinal surgery

AIM

To develop computer simulation of steps in vitreoretinal surgery using virtual reality technology.

MATERIAL AND METHODS

A workstation with three-dimensional position tracking stylus was attached to a Pentium II desktop PC with a graphic accelerator. Computer algorithms were developed using Open GL and Microsoft Visual C++ languages to control the interaction and update the visual feedback tracking the instruments. Soft tissue computer modelling was carried out to mimic the removal of a vitreous opacity. Lens touch with the instruments was also detected. Mathematical modelling to allow for lens distortion was taken into account.

RESULTS

A virtual reality computer model has been developed that can simulate initial steps of vitreoretinal surgery. Soft tissue modelling of the vitreous opacity and its removal by the vitrector was successfully simulated. The movements of the active and passive instruments in the dummy eye corresponded to the movements on the computer screen. On evaluation of the system, there was a minimal but discernable time lag between the stylus movement and the visual feedback. There was no tactile feedback when the lens touch was simulated. No further complex vitreoretinal surgery simulation was possible at this stage.

Evaluation of posturing in macular hole surgery

AIM

To objectively evaluate the postoperative face down posturing in macular hole surgery.

MATERIALS AND METHODS

An electronic device called 'Maculog' was developed consisting of three basic components, a mercury switch triggered by the angle of tilt placed inside an earpiece, a data-recording device connected to the earpiece with cables and a windows based software program, specially written to analyse the recorded data in the form of tables and graphs. Ten patients undergoing macular hole surgery were fitted with the device on the first postoperative day before discharge. They were also asked for a subjective record of their posturing times. Four patients were given a posturing chair to take home. The device was retrieved after the first week and the data were downloaded to a PC for analysis. The actual posturing times recorded on the device were compared to the patients' own recollections. Results In all ten patients the actual posturing time was less than the time they had recorded themselves. The average actual posturing time was 48% of the perceived posturing time. The worst time for posturing, as expected, was between midnight and early morning. The compliance was better in patients who used the posturing chair.

CONCLUSIONS

It is feasible to quantify the time of posturing using an electronic device and computer analysis. The study has shown that the actual posturing time is significantly less than the perceived posturing time. A further large study using 'Maculog' is now planned to correlate actual posturing time to the results of macular hole surgery.

Telemedicine in ophthalmology

Comprehensive telemedicine promises a world of medicine freed of geographic borders, time zones, and personnel shortages. It could open the door to more accessible medical delivery systems and economical widespread screening for disease. No region of the world would be too remote or too poor to receive high quality medical care. This article traces the development and current applications and initiatives in the field of telemedicine as applied to ophthalmology in the wider sense. Uses for clinical diagnosis and management, screening, research, education and peer interaction are discussed.

Prognostic significance of apoptosis in squamous cell carcinoma of oral cavity with special reference to TNM stage, histological grade and survival

Apoptotic count was assessed in 38 cases of squamous cell carcinoma of oral cavity by light microscopy and correlated with TNM stage, histological grade and survival. A direct correlation with the TNM stage (p = 0.0166) and an inverse correlation with the histological grade (p = 0.03) was found, however no correlation was found with the survival. Apoptotic count was significantly different between well and moderately differentiated carcinoma (p = 0.347) and well and poorly differentiated carcinoma (p = 0.0190). Thus apoptotic count may have prognostic value particularly in combination with staging and histological grade.

[Testing a computer-assisted bending machine for manufacturing orthodontic treatment elements]

The use of suitable orthodontic devices producing desired defined force systems is of importance for successful orthodontic treatment. Bending loops can be difficult and time-consuming. Computerised fabrication would enable very precise reproduction of individual loops. A bending machine has now been developed within the framework of a computer-assisted treatment concept. In this study, a prototype machine was used to fabricate U-, T- and delta loops made of stainless steel, cobalt chromium and titanium molybdenum wire. The various geometric parameters of each loop were measured to determine how precisely they had been produced. Furthermore, the force system of each loop were experimentally investigated during simulated activation in an orthodontic measurement and simulation system. The results indicate that the geometric parameters had an average error of 2.8 degrees for angles and 0.9 mm for lengths. Owing to the fabrication errors, loops of the same type produced different force systems. Overall, the new bending machine can fabricate different types of loop, but the requirements of very precise fabrication are currently not met. This fact, together with further limitations in terms of configuration, means that the machine cannot be used routinely at present. However, the machine can nevertheless be considered a good basis for further development.