Enhancing quantum phase transitions in the critical point of Extended TC-Dicke model via Stark effect

A system of N two-level atoms, Tavis-Cummings Dicke (TC-Dicke) model, interacting with a one-mode electromagnetic radiation field in the presence of the Stark shifts is studied, which is expected to predict new phenomena that are not explored in the original TC-Dicke model. We obtained the potential energy surface of the system using a trial state the direct product of coherent states in each subspace. In the frame of mean-field approaches, the variational energy is evaluated as the expectation value of the Hamiltonian for this state. The order of the quantum phase transitions is determined explicitly and numerically. We estimate the ground-state energy and the macroscopic excitations in the superradiant phase. Moreover, we investigated the critical properties of the TC-Dicke model in the classical spin limit and coherent state. We observed that in the thermodynamic limit, the energy surface takes a simple form a direct description of the phase transition. Moreover, it is found that when the microwave amplitude changes the new phase transition occurs with the Stark shift. The analytical solutions and numerical results, which appear in this paper are agreement with our paper which published recently in Int. J. Mod. Phys. B when we studied the same model using a different coherent state.

Combined Doppler ultrasound and platelet indices for prediction of preeclampsia in high-risk pregnancies

Objectives: To evaluate Doppler ultrasound and platelet indices for the prediction of preeclampsia (PE).Design: Prospective observational study.Methods: The study included 270 normal pregnancy primigravida <20 years at 20-24-week gestation. Doppler ultrasound was done to detect uterine artery diastolic notch and to measure the pulsation index (PI) and the resistance index (RI). The platelet count (PC), mean platelet volume (MPV), platelet distribution width (PDW) and platelet large cell ratio (Plcr) was measured by automated blood picture.Outcome: Validity of combined tests in prediction of PE.Results: Patients who developed PE had significant higher percentage of diastolic notch, higher mean PI, RI, and significant increase of MPV and PDW than normotensive women (p < .001). Patients with abnormal Doppler and abnormal platelet indices had significant higher incidence of severe PE (p < .001).Conclusion: Abnormal platelet indices combined with abnormal Doppler is a predictor of severity rather than the rate of development of PE.

Mobilization of the outer cavernous membrane decreases bleeding and improves resection in spheno-clinoidal meningiomas without cavernous sinus extension: A randomized controlled trial

Objective

The aim of this study was to determine whether adding mobilization of the outer cavernous sinus membrane as a part of the approach, in large spheno-clinoidal meningiomas without cavernous sinus extension, would reduce bleeding and increase the extent of resection.

Methods:

This prospective randomized controlled trial was held between February 2016 and April 2017 at Cairo University Hospitals. The study recruited 94 patients with spheno-clinoidal meningiomas without cavernous sinus involvement. Patients were randomly assigned (by a computer based randomization system) into two groups; the treatment group, in which the patients received mobilization of the outer layer of the lateral wall of the cavernous sinus, prior to opening of the dura; and, the control group, in which the patients were operated by a direct opening of the dura without cavernous sinus dissection. The primary outcome of this study was the difference in the amount of blood lost during surgery between both groups of patients. The secondary outcome variables were the estimated blood loss (EBL) calculated according to Mercurelli's formula, the extent of tumor resection and the amount of blood transfused.

Results:

The amount of blood loss and estimated blood loss (EBL) were significantly less in the "with mobilization group" with the P value being 0.00 and 0.013, respectively. Additionally, the amount of residual tumor was compared between both the groups and it showed that the group of patients who have received mobilization of the outer cavernous sinus membrane had a higher rate of radical resection as expressed by a lower volume of residual tumor (P value 0.005).

Conclusion:

In large spheno-clinoidal meningiomas without cavernous sinus involvement, routine mobilization of the outer cavernous sinus membrane reduces bleeding. This helps in a better visualization of cranial nerves in a relatively avascular field as it enables the performance of neurovascular dissection in an earlier phase of surgery. It also enables a more radical resection.

Predictors of Mortality in Living Donor Liver Transplantation

BACKGROUND

Egypt has the highest prevalence of the world hepatitis C virus (HCV) load. Hence, the problem of end-stage liver disease (ESLD) is considered a huge burden on the community. Living donor liver transplantation (LDLT) is the only source of donation in Egypt till now. Survival rates had shown significant improvement in the past decades. This study provides analysis of the mortality rates and possible predictors of mortality following LDLT. It also aids in developing a practical and easy-to-apply risk index for prediction of early mortality.

PATIENTS AND METHODS

This study is a retrospective study that was designed to analyze data from 128 adult patients with ESLD who underwent LDLT in the Liver Transplantation Unit at Faculty of Medicine, Cairo University. Early and late mortality were identified. All potential risk factors were tested using univariate regression for association with early and late mortality. Significant variables were then entered into a multivariable logistic regression model for identifying the predictors for mortality.

RESULTS

Sepsis was the most common cause of early mortality. Early mortality and 1-year mortality were 29 (23%) and 23 (18%), respectively. Model for End-Stage Liver Disease (MELD) score, intraoperative packed red blood corpuscles (RBCs), and duration of intensive care unit (ICU) stay were found to be independently associated with early mortality.

CONCLUSION

A MELD score >20, intraoperative transfusion >8 units of packed RBCs, and ICU stay >9 days are three independent predictors of early mortality. Their incorporation into a combined Risk Index can be used to improve outcomes of LDLT.

Serum vitamin D level in Egyptian children with Familial Mediterranean fever

BACKGROUND

The aim of the study is to measure plasma vitamin D levels in a group of Egyptian children with familial Mediterranean fever (FMF) compared to healthy children.

METHODS

The study enrolled 52 children with FMF and 40 apparently healthy controls. Serum vitamin D level was measured by enzyme-linked immunosorbent assay.

RESULTS

The mean serum vitamin D level was significantly lower in children with FMF than control group (12.3±3.4 and 21.2±3.5ng/mL, respectively, p<0.001). Vitamin D level was significantly lower in female patients than males (11.3±2.9, 13.2±3.6, respectively p=0.04). No statistically significant relations were detected between vitamin D level and different clinical, laboratory and genetic variables.

CONCLUSION

Vitamin D levels were lower in Egyptian FMF children than healthy controls. There is a speculation that vitamin D deficiency in FMF patients may be related to inflammation. Further studies with larger number of patients before and after Vitamin D, therapy may be needed. Supplementation with high doses of vitamin D seems appropriate for children with FMF.

Different Score Systems to Predict Mortality in Living Donor Liver Transplantation: Which Is the Winner? The Experience of an Egyptian Center for Living Donor Liver Transplantation

INTRODUCTION

Many scoring systems have been proposed to predict the outcome of deceased donor liver transplantation. However, their impact on the outcome in living donor liver transplantation (LDLT) has not yet been elucidated. This study sought to assess performance of preoperative Model for End-Stage Liver Disease (MELD) score in predicting postoperative mortality in LDLT and to compare it with other scores: MELDNa, United Kingdom End-Stage Liver Disease (UKELD), MELD to serum sodium ratio (MESO), updated MELD, donor age-MELD (D-MELD) and integrated MELD (iMELD).

METHODS

We retrospectively analyzed data from 86 adult Egyptian patients who underwent LDLT in a single center. Preoperative MELD, MELDNa, MESO, UKELD, updated MELD, D-MELD, and iMELD were calculated. Receiver-operator characteristic (ROC) curves and area under the curve (AUC) were used to assess the performance of MELD and other scores in predicting postoperative mortality at 3 months (early) and 12 months.

RESULTS

Among the 86 patients, mean age 48 ± 7 years, 76 (88%) were of male sex and 27 (31.4%) had died. Preoperative MELD failed to predict early mortality (AUC = 0.63; P = .066). Comparing preoperative MELD with other scores, all other scores had better predictive ability (P < .05), with D-MELD on the top of the list (AUC = 0.68, P = .016), followed closely by UKELD (AUC = 0.67, P = .025). After that were iMELD, MESO, and MELDNa with the same predictive performance (AUC = 0.65; P < .05); updated MELD had the lowest prediction (AUC = 0.640; P = .04). Moreover, all scores failed to predict mortality at 12 months (P > .05).

CONCLUSIONS

Preoperative MELD failed to predict either early or 1-year mortality after LDLT. D-MELD, UKELD, MELDNa, iMELD, and MESO could be used as better predictors of early mortality than MELD; however, we need to develop an effective score system to predict mortality after LDLT.

Fas/Fas Ligand pathways gene polymorphisms in pediatric renal allograft rejection

BACKGROUND

An essential milestone in pediatric transplantation is to find noninvasive biomarkers to monitor acute rejection (AR). In this retrospective (Case-control) study, we examined the role of Fas -670A/G and Fas Ligand (FasL) -843C/T gene polymorphisms in allograft nephropathy in pediatric renal transplant recipients.

METHODS

In 47 pediatric kidney transplant recipients and 20 healthy controls, Fas -670A/G and FasL -843C/T gene polymorphisms as well as serum soluble Fas Ligand level (sFasL) were measured.

RESULTS

Serum sFasL levels were significantly higher in transplant recipients children than that in controls (548.25±298.64pg/ml vs 143.17±44.55pg/ml, p=0.0001). There was no significant difference between patients with AR and those without AR in regards to serum sFasL levels (567.70±279.87pg/ml vs 507.85±342.80pg/ml, p=0.56). Fas -670A/G genotypes or alleles were not significantly different between controls and transplant recipients and among transplant recipients with and without AR. (P>0.05 for all). FasL -843C/T genotypes were not different between transplant recipients and controls and among transplant recipients with and without AR (P>0.05 for all). However, Frequency of C allele in transplant patients was significantly higher than that in the control group (44.68% vs 25%, P=0.03). FasL -843C/T alleles were significantly different between patients with and without AR (P=0.03). The percentages of C allele were higher in children with AR (58.82% vs 36.67%). We found that serum FasL and serum creatinine were variables that were independently associated with AR.

CONCLUSION

This study suggests that FasL gene polymorphisms in peripheral blood might be accurate in detecting cellular AR.

AMBULANT FLEXIBLE CYSTOSCOPY FOR FOLLOW-UP OF Ta-TI UROTHELIAL CARCINOMA OF THE URINARY BLADDER: PAIN PERCEPTION AND COST EFFECTIVE

Ambulant flexible cystoscopy is the standard procedure in the urological practice for follow-up of Ta-T1 urothelial carcinoma (UC) due to its ability to survey the bladder for a variety of indications. It is the principal means of diagnosis and surveillance of bladder tumors. The follow-up of patients treated for Ta-T1 UC is of great importance because of the high incidence of recurrence and progression of the disease, whereby patients with Ta-T1 UC undergo cystoscopy every three months. The aim of this study to evaluate the procedure of ambulant flexible cystoscopy in proper diagnostic follow-up of Ta-T1 UC, patient's acceptance in regard to pain tolerance, non-hospital stay and expenses. Twenty one patients (18 male and 3 female) were diagnosed before as Ta-T1 UC by rigid cystoscopy and transuretheral resection of bladder (TURB) lesion scheduled for follow up by flexible cystoscopy under local anesthesia using 20 ml 2% lidocain gel on an ambulatory bases. Comparison was done using a cohort of 32 patients who underwent the procedure of follow-up of Ta-T1 cystoscopy and TURB using rigid cystoscopy and resectoscope. Seventeen patients 80.9% (16 male and 2 female) proved to be bladder free from recurrent lesion, 4 patients {19.1 %} (3 males and one female) which revealed recurrent lesions in spite of that the urinary bladder was free in pelvic ultrasonography. Cold cup biopsy from the lesions sent for histopathological examination which revealed recurrence of the tumor in 3 patients (two patients with Ta and one patient T1. TURB was done to have complete resection in 4 patients, the histopathological examination revealed ulcerating mucosa and free lamina propria in 3 specimens, and T2 in the fourth specimen. Comparison between the 2 groups revealed more patient's acceptance for the flexible cystoscopy group as regard pain tolerance, non-hospital stay and expenses. Ambulatory flexible cystoscopy with 20 ml of 2% lidocaine gel anesthesia is tolerated well by patients, with advantage of no hospital stay in the regular follow up of Ta-T1 tumors, pain perception was accepted by all patient provided delayed cystoscopy after lidocaine-gel instillation.

Left atrial dyssynchrony time measured by tissue Doppler imaging to predict atrial fibrillation recurrences after pulmonary vein isolation

OBJECTIVE

In this study we assess the value of left atrial dyssynchrony time measured by tissue Doppler imaging (TDI) to predict recurrences after pulmonary vein isolation (PVI) in patients with paroxysmal and persistent atrial fibrillation (AF).

METHODS

One hundred sixty patients (57 ± 7.5 years, 122 males) with symptomatic drug-refractory paroxysmal and persistent AF, undergoing PVI were enrolled in our study. PA peak time by tissue Doppler imaging (PApeak-TDI) is defined as the time measured from the start of P wave in lead II to the peak of A wave on the tissue Doppler tracing. Left atrial dyssynchrony was measured by subtracting the PApeak-TDI time measured at the mid-inter atrial septum from the PA peak-TDI time measured at the left atrial midlateral free wall, (LA dyssynchrony = PApeak TDI lateral-PApeak TDI septal).

RESULTS

During a mean follow-up of 12 ± 3 months, recurrences occurred in 50 out of 160 patients. Patients with recurrence of atrial fibrillation had larger left atrial dyssynchrony time (26.5 ± 2.4 ms vs. 23.5 ± 2.3 ms, p < 0.001). Left atrial dyssynchrony time of 25 ms has the best combined sensitivity and specificity (74% and 63% respectively) along with positive predictive value 53% and negative predictive value 85.5%. LA dyssynchrony time ≥ 25 ms was found to discriminate patients prone to AF recurrences over time. Multivariate regression analysis showed that left atrial dyssynchrony time (HR per ms: 1.69, p<0.001) was identified as independent predictor of AF recurrence.

CONCLUSION

Left atrial dyssynchrony time is good clinical predictor of recurrence of AF after PVI in patients with paroxysmal and persistent AF.

Migration of human umbilical cord blood cells into rat liver

BACKGROUND AND OBJECTIVES

Cell therapy provides an effective strategy for the treatment of an impaired liver. Human umbilical cord blood progenitor cells have the potential to differentiate into hepatocytes. Progenitor cells transplanted into the spleen could migrate directly into the liver through portal circulation. To track migration of human umbilical cord blood progenitor cells in cirrhotic rat liver after intrasplenic transplantation and to prove the possibility similar behavior of human umbilical cord blood nucleated cells in humans.

METHODS AND RESULTS

Umbilical cord blood samples from full-term deliveries will be collected after obtaining an informed consent from the mother. The collection procedure will be conducted after completion of delivery and will not interfere with the normal obstetric procedures. Adult male Sprague Dawley rats were subjected to liver cirrhosis by intraperitoneal injection of thioacetamide. Cirrhotic rats were treated with human umbilical cord blood nucleated cells by intra-splenic transplantation. Migration of intrasplenic transplanted human umbilical cord blood cells to the liver was successfully documented with Immunohistochemistry. The liver and spleen from recipient animals were removed. Histopathological and immunohistochemical analysis were performed 20 weeks after intrasplenic injection of the cells. Intrasplenically injected cells migrate to the liver of recipient animals.

CONCLUSIONS

Human cord blood nucleated cells have the potential to differentiate into hepatocytes and substantially improve the histology and function of the cirrhotic liver in rats. Relocation into liver after intrasplenic transplantation could be detected by immunohistochemistry. Transdifferentiated cells could be efficiently stained with antihuman hepatocytes.

P wave indices to predict atrial fibrillation recurrences post pulmonary vein isolation

Background

P-wave indices are appealing markers for predicting atrial fibrillation (AF) recurrences post ablation.

Objective

This study evaluates the value of P wave indices to predict recurrences post pulmonary vein isolation (PVI) in patients with paroxysmal AF.

Methods

We selected 198 patients (57 ± 8 years, 150 males) with symptomatic drug-refractory paroxysmal AF undergoing PVI in our hospital. A 12-lead electrocardiogram was used to measure P wave duration in lead II, P wave terminal force (PWTF) in lead V1, P wave axis and dispersion.

Results

During a follow-up of 9 ± 3 months, recurrences occurred in 60 (30.3%) patients. The patients that had AF recurrence had longer mean P wave duration (122.9 ± 10.3 vs 104.3 ± 14.2 ms, p < 0.001), larger P wave dispersion (40.7 ± 1.7 ms vs 36.6 ± 3.2 ms, p < 0.001). P wave duration ≥ 125 ms has 60% sensitivity, 90% specificity, positive predictive value (PPV) of 72% and negative predictive value (NPV) of 83.7%, whereas P wave dispersion ≥ 40 ms has 78% sensitivity, 67% specificity, PPV of 51% and NPV of 87.6% 48/66 (72.7%) patients with PWTF ≤ - 0.04 mm/second vs 12/132(9%) with PWTF > -0.04 mm/second showed recurrence of AF (p < 0.001). P wave axis was not different between two groups. On multivariate analysis, P wave indices were not independent from left atrial size and age.

Conclusions

P wave duration ≥ 125 ms, P wave dispersion ≥ 40 ms and PWTF in V1 ≤ - 0.04 mm/sec are good clinical predictors of AF recurrences post PVI in patients with paroxysmal atrial fibrillation; however they were not independent from left atrial size and age.