Abstract TMP119: Early Cerebral Ischemic Events in Symptomatic Carotid Stenosis are Related to Plaque Inflammation

Background and aims: Symptomatic carotid stenosis is associated with an increased risk of early stroke recurrence. Severity of the stenosis, current basis of revascularization, explains only the cerebral ischemic mechanism of regional hypoperfusion. Plaque inflammation, the initiating event for plaque rupture and thromboembolism (artery-to-artery embolism), is not evaluated routinely. Using 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography (CT) and high resolution magnetic resonance imaging (HR-MRI), we investigated the role of plaque imaging and stroke recurrence in our cohort of stroke patients with recently symptomatic carotid stenosis.

Methods: This ongoing prospective study included consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). FDG uptake was quantified as mean standardized uptake values (SUV, g/ml). The ratio of T1 hyperintensity of carotid plaque to the ipsilateral sternocleidomastoid muscle (SCM) was recorded on T1-weighted fat suppressed images. Patients were followed prospectively for stroke recurrence within 90-days. Embolic potential of carotid plaque is estimated by presence of spontaneous microembolic signals (MES) on extended transcranial Doppler monitoring of ipsilateral middle cerebral artery.

Results: Of the 33 patients included in the study, 6 (18%) suffered from recurrent cerebral ischemic event in the same vascular territory within 90-days. Compared to patients without subsequent cerebral ischemic events, patients with recurrent cerebral ischemia showed higher mean T1 carotid-SCM ratio (2.49 versus 1.53; p<0.0001) and higher mean SUV value in the carotid plaque (3.52g/ml versus 1.51g/ml; p<0.0001). Higher T1 carotid-SCM ratio on HR-MRI (OR 4.249, 95%CI 1.818-5.18; p<0.0001), higher mean SUV on FDG-PET (OR 3.050, 95%CI 5.586-28.571; p=0.005) and MES on TCD (OR 2.186, 95%CI 1.652-47.619;p=0.037) were independent predictors of recurrent cerebral ischemia.

Conclusions: FDG-PET/CT and HR-MRI imaging of carotid stenosis helps in identification of patients at higher risk of subsequent cerebral ischemic events and may aid in better therapeutic decision-making.

Abstract TP443: Early Cognitive Decline in Patients with Symptomatic Carotid Stenosis is Related to Plaque Inflammation and Concomitant Intracranial Stenosis

Background and aims: Symptomatic carotid stenosis is associated with an increased risk of early stroke recurrence. Post-stroke vascular cognitive impairment is highly prevalent with significant functional consequences. However, reliable biomarkers for early prediction of cognitive decline are not well established. We postulated that regional hypoperfusion due to carotid stenosis would impair cognitive performance. Hence, we evaluated the cognitive parameters at baseline and their natural course during 90-days of follow up.

Methods: This ongoing prospective study included consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). Data regarding demographics and vascular risk factors were recorded. Cognitive parameters were assessed with the 30-point mini-mental scale (MMSE) and Montreal Cognitive Assessment (MoCA). All patients underwent carotid duplex sonography and 18-fluorodeoxyglucose (FDG) Positron Emission Tomography (PET) of carotid arteries. Embolic potential of the carotid plaque is estimated by presence of spontaneous microembolic signals (MES) on extended transcranial Doppler monitoring of the middle cerebral arteries. Patients are followed prospectively for change in cognitive parameters.

Results: Of the 33 patients included in this study, 7 (21%) demonstrated deterioration of their cognitive parameters (MMSE in 4, MOCA in 5 and both in 6) during 90-day follow up. Only high Standard Uptake Value (SUV) on PET (3.62g/ml in cognitive-deterioration group versus 1.72g/ml in the unaffected group; p=0.01) and presence of concomitant intracranial stenosis (p=0.01) were associated with cognitive deterioration. Of the 7 cases who underwent carotid revascularization, 5 (71%) demonstrated improved cognitive performance at day-90.

Conclusions: Early cognitive decline is common among patients with symptomatic stenosis of the extracranial carotid artery, especially when associated with concomitant intracranial stenosis and plaque inflammation.

Comparison of semen analysis by manual and automated method

Background: Semen analysis is used to evaluate male fertility. The aim of this study was to compare the results of semen analysis using manual method and automated sperm analyzer.Materials and Methods: This was a comparative study of 50 cases of semen analysis done in the Department of Pathology at the B.P. Koirala Institute of Health Sciences from March 2009 to March 2010. The automated sperm analyzer did not show the WHO parameters of patients who had functional sperm count (FSC) less than five hundred thousand (500,000). Semen analysis of each of the case included in the study was done by manual and automated method (using SQAII-P analyzer).Results: Out of 31 patients, the mean age of the patients was 28.56 years with youngest patient of 20 years and eldest of 45 year. Sensitivity and specificity was 100% in analysis of sperm concentration by both the methods. Sperm motility analysis showed 100% sensitivity and 81.81% specificity. Sperm morphology analysis showed 100% sensitivity and 34.48% specificity.Conclusion: It was observed that the automated method is much quicker and precise than the conventional, manual method for semen analysis.

Externally limited defect generation in multiwalled carbon nanotubes upon thermal annealing, and possible mechanism

Structural defects in multiwalled carbon nanotubes (MWCNTs) are found to increase upon moderate thermal annealing below 1400 K in an argon atmosphere. The defects are estimated using the ID/IG ratio in Raman spectroscopy of MWCNTs and confirmed by a direct observation using high-resolution transmission electron microscopy (HRTEM). HRTEM shows that the structural defects are created due to large damage to the outer walls of the nanotubes, while inner walls do not sustain any damage. The generation of defects on MWCNTs is attibuted to mechanical abrasion between the MWCNTs in contact, augmented by the momentum transfer from the flow of hot gas. A possible mechanism is proposed and experimentally validated by means of modulating the chemical environment of annealing from argon to hydrogen.

Structural analysis of lead magnesium niobate using synchrotron powder X-ray diffraction and the Rietveld method

The room-temperature synchrotron powder X-ray diffraction pattern of the single phase perovskite lead magnesium niobate (PMN) has shown significant broadening in the q range ∼ 5-7 Å(-1) compared with standard LaB6 synchrotron powder X-ray diffraction data, taken under similar conditions. This broadening/asymmetry lies mainly towards the lower 2θ side of the Bragg peaks. Attempts to fit this data with the paraelectric cubic phase (Pm\bar 3m) and the local rhombohedral phase (R3m) corresponding to polar nanoregions (PNRs) are made using the Rietveld method. Rietveld refinements show that neither cubic (Pm\bar 3m) nor rhombohedral (R3m) symmetry can fit this XRD pattern satisfactorily. The two-phase refinement fits the experimental data satisfactorily and suggests that the weight percentage of the PNRs is approximately 12-16% at room temperature. The unit-cell volume of these rhombohedral PNRs is approximately 0.15% larger than that of the unit cell volume of the paraelectric cubic phase.

Mask-less deposition of Au-SnO2 nanocomposites on CMOS MEMS platform for ethanol detection

Here we report on the mask-less deposition of Au-SnO2 nanocomposites with a silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) micro electro mechanical system (MEMS) platform through the use of dip pen nanolithography (DPN) to create a low-cost ethanol sensor. MEMS technology is used in order to achieve low power consumption, by the employment of a membrane structure formed using deep reactive ion etching technique. The device consists of an embedded tungsten micro-heater with gold interdigitated electrodes on top of the SOI membrane. The tungsten micro-heater is used to raise the membrane temperature up to its operating temperature and the electrodes are used to measure the resistance of the nanocomposite sensing layer. The CMOS MEMS devices have high electro-thermal efficiency, with 8.2 °C temperature increase per mW power of consumption. The sensing material (Au-SnO2 nanocomposite) was synthesised starting from SnO nanoplates, then Au nanoparticles were attached chemically to the surface of SnO nanoplates, finally the mixture was heated at 700 °C in an oven in air for 4 h. This composite material was sonicated for 2 h in terpineol to make a viscous homogeneous slurry and then 'written' directly across the electrode area using the DPN technique without any mask. The devices were characterised by exposure to ethanol vapour in humid air in the concentration range of 100-1000 ppm. The sensitivity varied from 1.2 to 0.27 ppm(-1) for 100-1000 ppm of ethanol at 10% relative humid air. Selectivity measurements showed that the sensors were selective towards ethanol when they were exposed to acetone and toluene.

A clinico-histopathological study on skin appendageal tumors

Background: Skin Appendageal tumors are a large and diverse group of tumors that are commonly classified according to their state of appendageal differentiation: follicular, sebaceous, eccrine and apocrine. Objectives of this study were to study the clinic-epidemiological profile of skin appendageal tumors and to correlate the clinico-histopathological diagnosis.Materials and Methods: This was a retrospective and prospective study which included all cases of skin adnexal tumours diagnosed histologically during the period of f

Microvessel density in Prostatic Lesions : Relevance to prognosis

Background:  Angiogenesis is required for growth and metastasis of tumor tissue. Quantization of angiogenesis by calculating the microvessel density can be done in histopathology specimens with the help of immunochemistry. In this study we used anti CD 34 antibody to highlight the endothelial cells and thus calculate microvessel density. Most studies have shown a positive correlation of microvessel density with increasing pathological grade and have also shown microvessel density as an independent predictor of cancer progression and survival. The present study was to find out the microvessel density in benign and malignant lesions of prostate and also to correlate the vascularity with increasing grade of cancer.Materials and methods:  Sixty five prostatic biopsies were evaluated for microvessel density using CD34 monoclonal antibody. Comparison was done between BPH and Carcinoma Prostate. MVD was correlated with Gleason’s score, weight of specimen and increasing age of patient. Effect of prostatitis on Microvessel density was studied.Results: Microvessel density was significantly higher in carcinoma prostate than in Benign Prostatic Hyperplasia. There was positive correlation of Microvessel density with increasing Gleason’s score. Microvessel was significantly increased in patients having symptoms for more than a year and also with biopsies revealing prostatitis. However, there was no significant correlation between Microvessel density and weight of specimen or increasing age.Conclusion: Since Microvessel density was found to be significantly higher in Prostatic Carcinoma and it showed positive correlation with Gleason’s score it can be added as one of the indicators for predicting the disease outcome. 

Abstract WP125: Plaque Inflammation Imaging in Carotid Stenosis and Recurrent Cerebral Ischemia

Background and aims: Symptomatic carotid stenosis is associated with an increased risk of early stroke recurrence. Currently, therapeutic decisions are largely based on the luminal narrowing, which mainly explain the cerebral ischemia related to regional hypoperfusion. Plaque inflammation, the initiating event for plaque rupture and thromboembolism (artery-to-artery embolism), is not evaluated routinely in patients with carotid stenosis. Using combined 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET)/computed tomography (CT), we investigated the role of plaque inflammation and stroke recurrence in our cohort of stroke patients with recently symptomatic carotid stenosis.

Methods: This ongoing prospective study aims to include consecutive patients within 30-days of recent stroke and ipsilateral carotid stenosis (≥50%). FDG uptake is quantified as mean standardized uptake values (SUV, g/ml). Patients are followed prospectively for stroke recurrence. Embolic potential of the carotid plaque is estimated by presence of spontaneous microembolic signals (MES) on continuous transcranial Doppler monitoring of the middle cerebral arteries (MCA) for 40 minutes.

Results: Of the 22 patients included in the study, 5 suffered from recurrent cerebral ischemic event in the same vascular territory within 90 days. In patients with recurrent cerebral ischemia, the mean SUV value in the carotid plaque on the side of symptomatic carotid stenosis was higher (3.46g/ml) as compared to the patients without stroke recurrence (1.72g/ml; p=0.03). MES were noted in 3/5 cases with recurrent cerebral ischemia as compared to 2/17 cases (p=0.001)

Conclusions: FDG-PET/CT aids in the imaging of plaque inflammation and identification of patients with higher risk of subsequent cerebral ischemic events. This ongoing study intends to develop a robust prediction model for risk stratification based on luminal stenosis and plaque characteristics for better therapeutic decision-making.

Abstract WMP110: Improvement in Cortical Versus Subcortical Perfusion After Superficial Temporal Artery- Middle Cerebral Artery (MCA) Bypass in Patients With Severe Stenosis of Intracranial Carotid and MCA

Background and Objective: The role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We have recently reported the improvement in clinical and various cerebral hemodynamic parameters after STA-MCA bypass surgery for severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR). Using acetazolamide challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT), we evaluated the differential improvement in metabolic perfusion in cortical and subcortical structures after STA-MCA bypass surgery.

Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) for CVR assessment using breath-holding index (BHI). Patients with impaired BHI (<0.69) were further evaluated with acetazolamide-challenged SPECT and STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent SPECT at 4±1 months. Using automated image analyzer, we evaluated differences in metabolic perfusion in cortical and subcortical regions.

Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR on SPECT. Fifty (60%) of them underwent STA-MCA bypass surgery. HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in all cases. Significantly better improvement (14.5%) in cerebral perfusion was noted in the cortical regions as compared to the subcortical regions (4.5%, p<0.005).

Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in cerebral perfusion, especially in the cortical regions.

Study of the microstructure information of GaAs epilayers grown on silicon substrate using synchrotron radiation

Williamson-Hall (WH) analysis is a well established method for studying the microstructural properties of epilayers grown on foreign substrates. However, the method becomes inapplicable in specific cases where the structure factor considerations and the presence of anti-phase domains forbid the data acquisition for certain reflections in conventional high-resolution X-ray diffraction (HRXRD) measurements. Here, this limitation is overcome by exploiting the large intensity (25 µW mm(-2)) and high photon energy (15.5 keV) of the X-ray beam obtained from a synchrotron radiation source. The lateral coherence length, vertical coherence length, tilt and micro-strain of GaAs epilayers grown on Si substrate have been successfully measured using the conventional WH analysis. The microstructure information obtained from the conventional WH analysis based on the data acquired at the synchrotron radiation source is in reasonable agreement with the results obtained from atomic force microscope and surface profiler measurements. Such information cannot be obtained on a laboratory-based HRXRD system where modification of the WH method by involving a set of parallel asymmetric crystallographic planes is found to be essential. However, the information obtained from the modified WH method is along a different crystallographic orientation.

Impact of Image Reconstruction Settings on Texture Features in 18F-FDG PET

Evaluation of tumor heterogeneity based on texture parameters has recently attracted much interest in the PET imaging community. However, the impact of reconstruction settings on texture parameters is unclear, especially relating to time-of-flight and point-spread function modeling. Their effects on 55 texture features (TFs) and 6 features based on first-order statistics (FOS) were investigated. Standardized uptake value (SUV) measures were also evaluated as peak SUV (SUVpeak), maximum SUV, and mean SUV (SUVmean).

METHODS

This study retrospectively recruited 20 patients with lesions in the lung who underwent whole-body (18)F-FDG PET/CT. The coefficient of variation (COV) of each feature across different reconstructions was calculated.

RESULTS

SUVpeak, SUVmean, 18 TFs, and 1 FOS were the most robust (COV ≤ 5%) whereas skewness, cluster shade, and zone percentage were the least robust (COV > 20%) with respect to reconstruction algorithms using default settings. Heterogeneity parameters had different sensitivities to iteration number. Twenty-four parameters including SUVpeak and SUVmean exhibited variation with a COV less than 5%; 28 parameters, including maximum SUV, showed variation with a COV in the range of 5%-10%. In addition, skewness, cluster shade, and zone percentage were the most sensitive to iteration number. In terms of sensitivity to full width at half maximum (FWHM), 15 TFs and 1 FOS had the best performance with a COV less than 5%, whereas SUVpeak and SUVmean had a COV between 5% and 10%. Grid size had the largest impact on image features, which was demonstrated by only 11 features, including SUVpeak and SUVmean, having a COV less than 10%.

CONCLUSION

Different image features have different sensitivities to reconstruction settings. Iteration number and FWHM of the gaussian filter have a similar impact on the image features. Grid size has a larger impact on the features than iteration number and FWHM. The features that exhibited large variations such as skewness in FOS, cluster shade, and zone percentage should be used with caution. The entropy in FOS, difference entropy, inverse difference normalized, inverse difference moment normalized, low gray-level run emphasis, high gray-level run emphasis, and low gray-level zone emphasis are the most robust features.

Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries

OBJECT

Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment.

METHODS

Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events.

RESULTS

A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008).

CONCLUSIONS

STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive disease of the intracranial ICA or MCA results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Anesthetic management of Wolff-Parkinson-White syndrome in a pregnant patient posted for emergency caesarean section

The most common arrhythmia seen during pregnancy is paroxysmal supraventricular tachycardia and Wolff-Parkinson-White syndrome accounts for majority of this in such population. The presence of pre-disposing factors may facilitate the onset of tachyarrhythmias in previously asymptomatic parturients with the WPW syndrome such as increased hemodynamic, hormonal, autonomic, and emotional changes. Therefore, meticulous monitoring is essential perioperatively. Epidural anesthesia providing added advantage of hemodynamic stability and post-operative analgesia is preferred in such pregnant patients undergoing emergency cesarean section.

Incidental Enterobius Vermicularis infestation in surgically removed appendices with a clinical diagnosis of acute appendicitis: A retrospective analysis

Background: Appendiceal parasites can cause symptoms of appendicitis. Although the symptomatology imitates acute appendicitis clinically, the true nature of disease is diagnosed through histological examination. The aim of this study is to therefore determine the prevalence of E. Vermicularis in appendicectomy specimens to relate this to acute inflammation histologically.Materials & Methods: Histological data on all appendectomy specimens with a clinical diagnosis of acute appendicitis were retrieved from the archives of department of pathology, B.P.K.I.H.S, over the period of  five years (January 2004- December 2008) and was analyzed retrospectively.Results: There were a total of 1528 patients. M:F ratio being 1.2:1.Inflamed appendix constituted for 94.24% of all cases. There were a total of six (0.39%) appendicectomy specimens  which showed presence of oxyuriasis appendix. Though all patients with oxyuriasis presented with appendicial colic only one (1) out of the six cases of oxyuriasis showed histologic evidence of inflammation. Conclusion: We conclude that enterobius does not frequently cause inflammation of appendix though it may clinically mimic acute appendicitis. Since it represents a disease curable without necessitating surgery, symptomatology awareness is stressed upon.Journal of Pathology of Nepal (2015) Vol. 5, 720-722

Transverse wobbling in ^{135}pr

A pair of transverse wobbling bands is observed in the nucleus ^{135}Pr. The wobbling is characterized by ΔI=1, E2 transitions between the bands, and a decrease in the wobbling energy confirms its transverse nature. Additionally, a transition from transverse wobbling to a three-quasiparticle band comprised of strong magnetic dipole transitions is observed. These observations conform well to results from calculations with the tilted axis cranking model and the quasiparticle rotor model.

Comparative study of glycated hemoglobin by ion exchange chromatography and affinity binding nycocard reader in type 2 diabetes mellitus

The aim of this study was to compare the level of glycated hemoglobin (HbA1c) in type 2 Diabetes Mellitus (DM) patients by two different methods namely Ion Exchange Chromatography and Affinity Binding Nycocard Reader. This is a cross-sectional study conducted on confirmed type 2 diabetes mellitus patients (n = 100) who visited Out Patients Department of the Universal College of Medical Sciences Teaching hospital, Bhairahawa, Nepal from November 2012 to March 2013. The diagnosis of diabetes mellitus was done on the basis of their fasting (164.46 ± 45.33 mg/dl) and random (187.93 ± 78.02 mg/dl) serum glucose level along with clinical history highly suggestive of type 2 DM. The HbA1c values of (7.8 ± 1.9%) and (8.0 ± 2.2%) were found in DM patients as estimated by those two different methods respectively. The highest frequency was observed in HbA1c > 8.0% indicating maximum cases were under very poor glycemic control. However, there were no significant differences observed in HbA1c value showing both methods are comparable in nature and can be used in lab for ease of estimation. The significant raised in HbA1c indicates complications associated with DM and monitoring of therapy become hard for those patients. Despite having standard reference method for HbA1c determination, the availability of report at the time of the patient visit can be made easy by using Nycocard Reader and Ion Exchange Chromatography techniques without any delay in communicating glycemic control, clinical decision-making and changes in treatment regimen.

Structural, magnetic, and dielectric studies on Gd0.7Y0.3MnO3

Structural, magnetic, specific heat, and dielectric studies were carried out on Y substituted (30 at. %) GdMnO(3) compound as a function of temperature. Anomalies occur at ~41 and 18 K, in the specific heat measurements and are ascribed to paramagnetic, to sinusoidal incommensurate antiferromagnetic transition (ICAFM) and ICAFM to commensurate antiferromagnetic transitions, respectively. Changes in the lattice parameters across these temperatures indicate magneto-elastic coupling present in the compound. However, in the dielectric measurements, an anomaly at 18 K alone is observed and is ascribed to a ferroelectric transition, giving rise to spontaneous ferroelectric ordering at low temperatures. This observation is supported by an anomaly in lattice parameters, across the transition temperature. From the frequency dependent dielectric studies, a strong coupling between Gd(3+) and Mn(3+) magnetic sublattices is inferred and Y substitution results in substantial changes in the relaxation process compared to that of GdMnO(3).

Dermcidin isoform-2 induced nullification of the effect of acetyl salicylic acid in platelet aggregation in acute myocardial infarction

The aggregation of platelets on the plaque rupture site on the coronary artery is reported to cause both acute coronary syndromes (ACS) and acute myocardial infarction (AMI). While the inhibition of platelet aggregation by acetyl salicylic acid was reported to produce beneficial effects in ACS, it failed to do in AMI. The concentration of a stress induced protein (dermcidin isoform-2) was much higher in AMI than that in ACS. Incubation of normal platelet rich plasma (PRP) with dermcidin showed one high affinity (K_d = 40 nM) and one low affinity binding sites (K_d = 333 nM). When normal PRP was incubated with 0.4 μM dermcidin, the platelets became resistant to the inhibitory effect of aspirin similar to that in the case of AMI. Incubation of PRP from AMI with dermcidin antibody restored the sensitivity of the platelets to the aspirin effect. Incubation of AMI PRP pretreated with 15 μM aspirin, a stimulator of the NO synthesis, resulted in the increased production of NO in the platelets that removed the bound dermcidin by 40% from the high affinity binding sites of AMI platelets. When the same AMI PRP was retreated with 10 μM aspirin, the aggregation of platelets was completely inhibited by NO synthesis.

Utility of prospective step sections in diagnostic skin histopathology for small biopsies

Background: Small skin biopsies have a cosmetic advantage and prospective step sections could potentially improve turnaround time without compromising diagnostic information. The study aimed to examine the use of prospective step sections of small skin biopsies and its effect on histopathological diagnosis and turnaround time. Materials and Methods: This was a hospital based cross-sectional study at Department of Pathology and Department of Dermatology, BPKIHS from June 2011- June 2012. Diagnoses /comment on three levels of prospectively taken 3mm biopsies were compared with those of 5mm biopsies taken from the same/similar lesion from 100 patients. Additional sections from 5mm biopsies were taken retrospectively. Percentage, proportion, mean, standard deviation, diagnostic sensitivity, kappa statistics and paired sample t- test were used as statistical tools. Results: Of 100 cases, 80 were diagnosed using 5mm biopsies while 73 were diagnosed using 3mm biopsies. On additional step sections of 3mm biopsies, 3 more cases were diagnosed. When compared with 5mm biopsies, the sensitivity of the 3mm biopsy rose from 90% to 93.8% after additional sections while the measure of agreement rose from 0.751 to 0.826.Mean turnaround time for prospectively sectioned 3mm biopsies was 2.56 days and that of retrospectively sectioned 5 mm biopsies was 4.64 days with their difference being statistically significant. Conclusion: A statistically significant decrease in turnaround time and an increase in sensitivity and agreement after step sections elucidates the utility of prospective step sectioned 3 mm biopsies in diagnostic skin histopathology. DOI: http://dx.doi.org/10.3126/jpn.v4i7.10298 Journal of Pathology of Nepal (2014) Vol. 4, 552-559  

Abstract T MP29: Impaired Vasodilatory Reserve on Acetazolamide-Challenged 99tc-hmpao-Spect is a Strong Predictor of Stroke Recurrence in Patients With Severe Steno-Occlusive Disease of Intracranial Carotid or Middle Cerebral Artery

Background: Intracranial stenosis carries an increased risk for cerebrovascular ischemia. In severe stenosis, cerebral autoregulation may be impaired due to inadequate cerebral vasodilatory reserve (CVR) & intracranial steal phenomenon (reversed-Robin Hood syndrome-RRHS). Identification of patients with inadequate CVR and RRHS may help in identifying high-risk patients.

Methods: In this prospective study, we included patients with symptomatic and severe stenosis of intracranial carotid (ICA) & middle cerebral artery (MCA). CVR was evaluated with transcranial Doppler (TCD) and breath-holding index (BHI) <0.69 determined inadequate CVR. RRHS was detected as transient velocity reduction in affected artery when flow increased in the reference artery. Patients with RRHS were further evaluated with acetazolamide-challenged 99Tc-HMPAO-SPECT.

Results: 126 patients (80 male, mean age 56yrs; range 23-78yrs) fulfilled our TCD criteria for inadequate CVR. HMPAO-SPECT showed impaired CVR in 84 (67%) patients. RRHS noted on TCD in 38 (45%) patients (median steal magnitude 14%; inter-quartile range, IQR 10) was confirmed by acetazolamide-challenged HMPAO-SPECT (median perfusion deficit 8%; IQR 13%) in 35 (92%) cases (sensitivity 82%, specificity 96% with positive predictive value 96%). A strong relationship between RRHS on TCD and SPECT was noted on ROC curve analysis (area under curve 0.93; 95% confidence interval 0.87-0.98;p<0.00001). Linear relationship was observed between impaired vasodilatory reserve and stroke recurrence during follow up (mean 35months; range 8 to 49months)- 56% in patients with RRHS versus 20% in patients with moderately impaired CVR versus 4% in patients with mildly impaired CVR (chi-square 18.42; df=2; p<0.001 for trend). RRHS on HMPAO-SPECT was an independent predictor of recurrent cerebral ischemic events (RR 1.9, 95%CI 1.2-4.2; p=0.03).

Conclusions: Among patients with severe intracranial stenosis, intracranial steal phenomenon is associated with high risk of cerebral ischemic events. Acetazolamide-challenged HMPAO-SPECT is reliable in the quantification of vasodilatory reserve for selecting a target group of patients for possible revascularization.

Abstract T MP26: Role of 99tc-hmpao Spect in the Assessment of Cerebral Hemodynamic Parameters After Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients With Severe Steno-Occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective: Although superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery in patients with symptomatic carotid occlusion failed to demonstrate any benefit, its role in symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated changes in hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) who underwent STA-MCA bypass for impaired cerebral vasodilatory reserve (CVR).

Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) evaluation and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (<0.69) were further evaluated with acetazolamide-challenged 99Tc-HMPAO-SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. TCD and SPECT were repeated in all patients at 4±1 months and they were followed-up for cerebral ischemic events.

Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR HMPAO-SPECT. Fifty (60%) of them underwent STA-MCA bypass while 34(40%) received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in STA-MCA bypass group. TCD BHI improved from a median (IQR) of -0.05 to 1.1 (p<0.001). Compared to 98% patients with impaired CVR on pre-operative SPECT, only 20% showed abnormal results on post-operative imaging (p<0.001). During follow-up (mean 35 months; range 8 to 49months), only 6/50 (12%) patients in bypass group developed cerebral ischemic events as compared to15/34 (44%) cases on medical therapy (absolute risk reduction 32%, p=0.006).

Conclusion: 99Tc-HMPAO SPECT with acetazolamide challenge is a reliable tool for the assessment of cerebral vasodilatory reserve in patients with severe steno-occlusive disease of intracranial ICA or MCA. STA-MCA bypass surgery in carefully selected patients results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.