Purification and characterization of Bacillus thuringiensis vegetative insecticidal toxin protein(s)

Bacillus thuringiensis subsp. aegypti C18 is an Egyptian isolate, obtained from dead pink bollworm larvae. Insecticidal active proteins against different insect were purified from BtaC18 strain during vegetative states. Both the bacterial pellet and cell-free supernatant obtained during vegetative growth had insecticidal activity against black cutworm (BCW). Bioassays revealed that the pellet after 48 h of growth is more potent and toxic against BCW. The toxin in the pellet was active at very high temperatures but lost toxicity after boiling or autoclaving. Proteins extracted from the BtaC18 pellet were further purified by ammonium sulfate precipitation, and the 40% fraction was then subjected to fast protein liquid chromatography (FPLC). Seven major protein peaks were detected after FPLC (Pi- a, b, c, d, e, f and g). Pic protein fraction was active against BCW with an estimated LC50  = 26 ng cm(-2) , Pid protein killed 50% of European corn borer (ECB) at 46 ng cm(-2) , and Pif showed insecticidal activity against western corn root worm (WCRW) with estimated LC50 was 94 ng cm(-2) . Based on the significant and high toxicity of Pic against BCW and Pif against WCRW, the 88- and 44-kDa proteins were further characterized by N-terminal amino acid sequencing.

SIGNIFICANCE AND IMPACT OF THE STUDY

Insecticidal activity of Bacillus thuringiensis subsp. aegypti was determined, and its vegetative insecticidal protein was subjected to FPLC for protein purification. This work contributes to improve understanding the different toxins secreted during vegetative growth of Bt. Moreover, the N-terminal amino acid sequences of 88-kDa protein was only 92% identical to that of vip3A, and for 44 kDa was 92% identical with Cry35a, suggesting that we might have identified a new genes. Finally, we have proven these proteins to be novel insecticidal agents that may complement the use of known insecticidal proteins derived from Bacillus.

Guidelines for the selection of tooth whitening products amongst those available on the market

BACKGROUND

Several tooth whiteners are available on the market, and the ideal choice should be determined by efficacy and optimal clinical results.

OBJECTIVES

The purpose of this study was to compare the reported clinical success rates of different tooth whitening products.

SEARCH STRATEGY

The relevant literature (1998 - 2011) was studied, using as sources the databases: Google Scholar, Science Direct, Medline and Pubmed.

SELECTION CRITERIA

The material was clearly identified, the manufacturers' instructions were respected and the sample size stated.

RESULTS AND CONCLUSIONS

This descriptive report on 49 papers focuses on the total colour change, measured with a calibrated shade guide and also numerically (colourimeter, chromameter or spectrophotometer), the relapse of the colour change and tooth sensitivity. In general, the dentist-supervised at-home bleaching and the in-office treatment gave approximately the same initial percentage improvement of tooth whitening. However, the relapse after a four week or longer period was significantly higher for the in-office treatment. The treatment of choice should be a dentist supervised at-home bleaching product which generally contains approximately 10% carbamide peroxide applied over about 14 days for about eight hours per night. Tooth sensitivity should not be a general problem although some subjects might choose to discontinue treatment as a result of sensitivity.

Is solitary kidney really more resistant to ischemia? An experimental canine study

PURPOSE

To our knowledge there are no evidence-based medicine data to date to critically judge the vulnerability of a solitary kidney to warm ischemia compared to paired kidneys.

MATERIALS AND METHODS

Ten dogs were exposed to open right nephrectomy to create a solitary kidney model (group 1). Ten dogs with both kidneys were considered group 2. All dogs underwent warm ischemia by open occlusion of the left renal artery for 90 minutes. Dogs were sacrificed at different intervals (3 days to 4 weeks). All dogs were reevaluated by renogram before sacrifice and histopathology of the investigated kidney. The proinflammatory markers CD95 and tumor necrosis factor-α were assessed using real-time polymerase chain reaction.

RESULTS

In group 1 clearance decreased by 20% at 1 week but basal function was regained starting at week 2. In group 2 clearance decreased more than 90% up to week 2. Recovery started at week 3 and by 4 weeks there was a 23% clearance reduction. Histopathological examination in group 1 revealed significant tubular necrosis (60%) at 3 days with regeneration starting at 1 week. In group 2 there was more pronounced tubular necrosis (90%) with regeneration starting at 2 weeks. The expression of proinflammatory markers was up-regulated in each group with higher, more sustained expression in group 2.

CONCLUSIONS

Solitary kidney in a canine model is more resistant to ischemia than paired kidneys based on radiological, pathological and genetic evidence.

DWI-MRI: single, informative, and noninvasive technique for prostate cancer diagnosis

Aim. To evaluate diffusion weighted image-MRI (DWI) as a single diagnostic noninvasive MRI technique for prostate cancer (PCa) diagnosis. Material and Methods. A prospective study was conducted between July 2008 and July 2009. Candidates patients were equal or more than 40 years old, with suspicious digital rectal examination (more than clinical T2) or PSA >4 ng/mL. Informed consent was signed. DWI-MRI was performed at 1.5 T with a body coil combined with a spine coil in consecutive 100 cases. The histopathology of biopsies has been used as reference standard. Two examiners were evaluating MRI and TRUS, both of them were blinded regarding pathological findings. Accuracy, specificity, and sensitivity were statistically analyzed. Results. Based on pathological diagnosis: group A (cancerous); 75 cases and group B (non-cancerous); 25 cases. Mean age was 65.3 and 62.8 years in groups A and B, respectively. Mean PSA was 30.7 and 9.2 ng/mL in groups A and B, respectively. Sensitivity of DWI was 58.3% while specificity was 83.8%. Accuracy of lesion detection was 52.4–77.8% (P < 0.05). Moreover, DWI at ADC value 1.2 × 10⁻³ mL/sec could determine 82.4% of true positive cases (P < 0.05). ADC values were lower with Gleason score ≥7 (P < 0.05). Conclusion. DWI could represent a non invasive single diagnostic tool not only in detection and localization but also in prediction of Gleason score whenever DWI is used prior to invasive TRUS biopsy. Furthermore, targeted single biopsy could be planned after DWI to minimize patient morbidity by invasive techniques.

Long-term outcome of grafts with multiple arteries in live-donor renal allotransplantation: Analysis of 2100 consecutive patients

Purpose

To analyse the long-term outcome in relation to multiple graft arteries (MGA) in live-donor renal transplantation, and assess its effect on graft and patient survival.

Patients and methods

Between March 1976 and November 2009, a total of 2100 live-donor renal transplants were carried out at our centre. Patients were stratified according to the number of graft arteries into two groups, i.e. MGA (two or more arteries; 237 patients) and single-graft artery (SGA; 1863 patients). Variables assessed included patient demographics, site of vascular anastomosis, ischaemia time, onset of diuresis, delayed graft function, acute tubular necrosis (ATN), acute rejection, vascular and urological complications. Moreover, long-term patient and graft survival were compared among both groups. Patients were followed up for a mean (SD) of 112 (63) months.

Results

Grafts with MGA were associated with a prolonged ischaemia time (P = 0.001) and ATN (P = 0.005). Vascular thrombosis (arterial and venous) had a higher incidence in MGA (2.5%) than SGA (0.6%) (P = 0.01). Both groups were not significantly different for the onset of diuresis, acute rejection and urological complications (P = 0.16, 0.23 and 0.85, respectively). Graft and patient survival were comparable in both groups. The mean (SD) 1-, 5-, 10- and 20-year graft survival rates (%) for MGA were 96.1 (1.26), 86.6 (2.39), 61.3 (4.42) and 33.8 (7.23), and 97.5 (0.36), 86.8 (0.84), 66.0 (1.35) and 37.3 (2.76) for SGA (P = 0.54).

Conclusions

Although there was a higher incidence of prolonged ischaemia time, ATN and vascular thrombosis in live-donor renal transplants with MGA, it did not adversely affect patient or graft survival. The early, intermediate- and long-term follow-up showed an outcome comparable to that in patients with SGA.

Surgical analysis of pediatric and adolescent sporadic pheochromocytoma: single center experience

INTRODUCTION

The aim of this study is to review our experience with sporadic pheochromocytoma in pediatrics and adolescents focusing upon surgical approach, incidence of malignancy, and recurrence rate.

MATERIALS AND METHODS

Between 1990 and 2007, 8 pediatric patients were diagnosed with sporadic pheochromocytoma. Demographic data, clinical and radiological findings, laboratory profile, preoperative preparation, surgical approach, operative findings, postoperative course as well as pathologic diagnosis of the removed specimen were reviewed.

RESULTS

Mean age of presentation was 13.1 ± 4.7 years. Five patients had right-sided masses, 1 harbored left-sided mass, and bilaterality was observed in 2 with mean size of 5.7 ± 1.3 cm. Computed tomography showed no evidence of local infiltration, regional lymphadenopathy or distant metastasis in all patients but two. Six masses were excised through thoraco-abdominal approach, 3 were removed laparoscopically, while percutaneous alcohol ablation was adopted for the last. We had one postoperative death (12.5%:1/8), and the remaining 7 patients were followed for a mean of 8.6 ± 3 years. Five patients never had recurrence. Bilateral recurrence developed in 2 patients, where they were safely excised in one patient and was a part of disseminated disease in the other. Malignant nature of the disease was proved in 2 patients and showed poor survival.

CONCLUSION

Under adequate anesthetic control, pediatric pheochromocytoma could be safely managed through both the open and laparoscopic approaches. Advanced radiological stage would suggest the malignant nature of the disease with dismal outcome. Long-term follow-up is warranted for possibility of delayed curable recurrence.

Does timing of post-renal transplant diuresis affect graft survival in live-donor renal transplants?

OBJECTIVE

To study the effect of timing of diuresis on short and long term graft survival in live-donor (LD) renal transplants.

METHODS

Between 1976 and 2005, 1747 consecutive LD renal transplants were performed in a single institution. Patients were classified according to timing of diuresis after vascular de-clamping; group 1 included patients with diuresis within 10 min; group 2 started diuresis between 10 and 60 min after de-clamping; group 3 started diuresis between 1 and 24 h after de-clamping; and group 4 started diuresis > 24 h after de-clamping. Patients' data were stored on an electronic database and were reviewed for risk factors and clinical relevance of timing of diuresis.

RESULTS

Groups 1-4 comprised 1598 (91.5%), 87 (5%), 44 (2.5%) and 18 (1%) patients, respectively. By multivariate analysis, vascular thrombosis was the significant risk factor for delayed diuresis. Delayed diuresis was significantly associated with the occurrence of acute tubular necrosis (ATN), and acute and chronic rejection. Graft and patient survival rates were significantly affected by the timing of diuresis. The 1-year graft survival rates were 93.8, 83.0, 83.6 and 55.6%, and the 5-year graft survival rates were 77.4, 59.4, 69.4 and 35.7% in groups 1, 2, 3 and 4, respectively (P < 0.001). The 1-year patient survival rates were 96.5, 84.4, 90.7 and 61.1% and the 5-year patient survival rates were 87.1, 72.0, 78.1 and 52.4% in groups 1, 2, 3 and 4, respectively (P < 0.001).

CONCLUSION

Delayed diuresis is a rare event after LD renal transplantation, which has an adverse effect on short- and long-term graft and patient survival.

Early versus late rehabilitation of erectile function after nerve-sparing radical cystoprostatectomy: a prospective randomized study

INTRODUCTION

Pharmacological rehabilitation of erectile function (EF) after nerve-sparing radical prostatectomy was repeatedly advocated.

AIM

To compare early vs. late penile rehabilitation in patients with nerve-sparing (NS) radical cystoprostatectomy based on a prospective randomized trial.

METHODS

Eighteen patients without spontaneous erection 8 weeks after NS radical cystoprostatectomy were randomly divided into two groups; group I and II who started the erectogenic therapy at the 2nd and 6th month postoperatively, respectively. The pharmacological therapy constitutes of sildenafil citrate twice weekly to be shifted to intracavernosal injection (ICI) of prostaglandin E1 (PGE1) if not responding. The treatment continued for 6 months in both groups.

MAIN OUTCOME MEASURES

The EF status was evaluated before and at the end of the treatment by International Index of Erectile Function questionnaire and penile Doppler ultrasonography (PDU).

RESULTS

Six out of nine patients recovered unassisted erection after treatment in group I compared to three out of nine patients in group II. Two patients in group I and three patients in group II were maintained on sildenafil therapy on demand basis. The remaining four patients were dependent on ICI of PGE1. At final evaluation, a significant improvement was found in the EF, the intercourse satisfaction and overall satisfaction domains (P = 0.02, 0.03, and 0.02, respectively) in group I compared with group II. Regarding PDU findings, significant improvement in end-diastolic velocity was elicited in the early rehabilitation group compared with the pretreatment value (P = 0.03) with no significant difference between both groups.

CONCLUSION

Early compared with delayed erectile rehabilitation brings forward the natural healing time of potency and maintains nerve-assisted erection.

Percutaneous Adrenal Biopsy for Indeterminate Adrenal Lesion: Complications and Diagnostic Accuracy

<i>Purpose:</i> To critically analyze the role, accuracy and safety of percutaneous adrenal biopsy for indeterminate adrenal lesions. <i>Materials and Methods:</i> Adrenal biopsies were performed in 15 among 214 patients (7%) diagnosed with adrenal masses being indeterminate on preoperative imaging. Definitive histopathology was obtained in all and overall sensitivity and negative predictive value were calculated. Safety of the procedure was reported. <i>Results:</i> The study included 8 male and 7 female patients with a mean age of 33.3 ± 20.3 years (range 7–65). Biopsy was carried out under computed tomography and ultrasound guidance in 12 and 3 patients, respectively. There were 2 nonrepresentative biopsies that were proved to be adrenocortical carcinoma and myelolipoma after adrenalectomy. Results of biopsy in the remaining 13 patients provided accurate diagnosis as proved by definitive histopathology in all but 2 in whom the final diagnosis was established as adrenocortical carcinoma while biopsy was paraganglioma in one and cortical adenoma in the other. Overall sensitivity and negative predictive value of adrenal biopsy was 73.3 and 60%, respectively. Apart from two mild hypertensive episodes following silent pheochromocytoma biopsy, no complications were reported. <i>Conclusions:</i> Percutaneous biopsy is a safe procedure for the diagnosis of pathologic conditions of the adrenal gland with a reasonable diagnostic aid.

Diagnosis and treatment of adrenal tumors: a single-center experience with 238 cases

OBJECTIVE

It was the aim of this study to review and analyze clinical data on the diagnosis and management of patients with adrenal masses.

PATIENTS AND METHODS

Between 1976 and 2005, 238 patients admitted to our institute with adrenal masses were reviewed. Incidence, clinical features, imaging technique findings, surgical approaches, morbidity and mortality, as well as pathological diagnoses were reported.

RESULTS

The series comprised 134 males and 104 females (mean age 33.3 +/- 20.3 years). Right-sided masses were more common (63.4%), with a mean size of 7.7 +/- 4 cm. Pain was the most frequent presenting symptom (53.4%), while 62 (26%) had a functional tumor. Incidentaloma was diagnosed in 49 patients (20.6%). Both computed tomography and magnetic resonance imaging showed a high diagnostic yield (sensitivities of 98.9 and 100%, respectively). Open adrenalectomy was performed in 153 patients (64.3%), while a laparoscopic approach was employed in 53 patients (22.3%). The intraoperative complication rate was 14.7%, the postoperative complication rate 6.1% and perioperative mortality 1.7%. Most of the excised masses were pheochromocytomas (26.4%).

CONCLUSIONS

Computed tomography is recommended as the first diagnostic modality to define and characterize adrenal masses. Laparoscopic adrenalectomy is currently replacing open surgery as the standard surgical management of adrenal masses.

Ischaemic posterior circulation stroke in State of Qatar

BACKGROUND

Ischaemic stroke features may show regional differences. Posterior circulation stroke (PCS) is of special interest, as symptomatology, course and outcome are usually different and complex. No significant studies or registries have reported on the characteristics and outcomes of PCS in our region.

METHODS

We prospectively collected data of 116 patients with PCS admitted from 2005 through 2008 in the only stroke admitting hospital in Qatar. Demographics, risk factors, clinical signs/symptoms, pattern of presentation, aetiology, imaging features, complications and outcome at discharge and follow-up were recorded.

RESULTS

Mean age was 53 years with 25% aged < or = 45, 85% were males. Demographically 47% were Arabs and 51% of South-Asian origin. Mean duration from onset to presentation was 29 h. Major risk factors were obesity (66%) and hypertension (61%). Minimal or fluctuating symptoms were present in 64%, while 9% had maximal deficit at onset. Thirty nine per cent had lesions in proximal territory and 23% in multiple territories. Around 41% had no occlusion, 16% had vertebro-basilar, 16% vertebral, 8% basilar occlusion. Etiologically 53% patients had large artery disease, 16% small vessel disease, and 17% cardioembolism. Seventy per cent of patients were discharged home, while 10% expired. Modified Rankin score (mRS) at discharge was < or = 2 in 53% and > or = 4 in 13% patients. At 30-day follow-up, 68% had mRS of < or = 2. Ninety-day survival status showed 89% alive with mRS < or = 2 in 73%.

CONCLUSION

The aetiology and lesion topography of PCS in this heterogeneous population differs from the pattern observed in other populations.

Comparison between a serous-lined extramural tunnel and T-limb ileal procedure as an antireflux technique in orthotopic ileal substitutes: a prospective randomized trial

OBJECTIVE

To compare the functional results from a prospective randomized trial of two different reflux-prevention techniques for ileal bladder substitution.

PATIENTS AND METHODS

In all, 60 patients with invasive bladder cancer were randomized to receive either a serous-lined extramural tunnel (group 1) or T-limb ileal procedure (group 2) as an antireflux technique for the ileal substitute. The preoperative evaluation included intravenous urography, radioisotope renography to evaluate glomerular filtration rates (GFRs) and renal cortical imaging with 99mTc- dimercaptosuccinic acid to assess parenchymal scarring. Evaluable patients were re-assessed by the same imaging, and by ascending studies.

RESULTS

The follow-up included 27 patients (49 units) in group 1 and 23 (45 units) in group 2, with a mean (sd) follow-up of 6.3 (0.5) and 7.4 (1.9), respectively. Uretero-ileal strictures were diagnosed in one renal unit in each group (P = 0.5). Ascending studies showed no reflux in any patients in group 1, while 13 renal units (29%) in group 2 were refluxing (P < 0.01). There was progressive cortical scarring with or with no significant reduction in GFR (>25%) in three and four renal units in groups 1 and 2, respectively. Among the 13 refluxing units in group 2, three showed a significant deterioration in GFR and one renal unit was diagnosed with progressive cortical scarring.

CONCLUSION

Both procedures provided a low rate of anastomotic stricture, with acceptable preservation of renal function. The serous-lined extramural tunnel provided a more effective antireflux mechanism.