A new molecular imprinted PEDOT glassy carbon electrode for carbamazepine detection

An electrochemical sensor for the detection of carbamazepine was fabricated by the electropolymerization of PEDOT on glassy carbon electrodes. Molecular imprinted polymer sites were synthesized by cyclic voltammetry on the electrodes' surfaces providing high selectivity and sensitivity towards carbamazepine molecules. Scanning electron microscopy validated the formation of the polymer. Extraction of carbamazepine from the polymer was performed by immersion in acetonitrile and validated by ultraviolet-visible spectroscopy along with cyclic voltammetry experiments comparing pre- and post-template extraction data. Further cyclic voltammetry and square-wave voltammetry tests aided in characterizing the electrodes' response to carbamazepine concentration in PBS solution with [Fe(CN)₆]^3-/4- as a redox pair/mediator. The limits of detection and quantification were found to be 0.98 x 10^-3 M and 2.97 x 10^-3 M respectively. The biosensor was highly sensitive to carbamazepine molecules in comparison to non-imprinted electrodes, simple to construct and easy to operate.

The effect of gestational age on trial of labor after Cesarean section

OBJECTIVES

To evaluate the effect of gestational age on the rate of successful vaginal delivery and the rate of uterine rupture in patients undergoing a trial of labor (TOL) after a prior Cesarean delivery.

STUDY DESIGN

This was a cohort study including patients with a live singleton fetus undergoing a TOL after a previous low transverse Cesarean delivery between 1988 and 2002. Patients were divided into three groups according to gestational age: 24-36 weeks 6 days, 37-40 weeks 6 days and > or = 41 weeks. Obstetric outcomes, including the rates of successful vaginal delivery and symptomatic uterine rupture, were compared between the groups. Multivariate logistic regression analysis was performed to adjust for potential confounding factors.

RESULTS

There were 253, 1911 and 329 patients in each group, respectively. In patients with advanced gestational age (> or = 41 weeks) the rate of uterine rupture was significantly higher (0% vs. 1.0% vs. 2.7%, p = 0.006) and the rate of successful vaginal deliveries was significantly lower (83% vs. 76.9% vs. 62.6%, p < 0.001). After adjusting for confounding variables, advanced gestational age was associated with a lower rate of successful vaginal delivery (odds ratio 0.68, 95% CI 0.51-0.89), and a higher rate of uterine rupture (odds ratio 2.85, 95% CI 1.27-6.42) when compared to 37-40 weeks 6 days.

CONCLUSION

Advanced gestational age is associated with higher rates of failed TOL and uterine rupture.

The racial disparity in outcomes in endometrial cancer: could this be explained on a molecular level?

OBJECTIVE

The racial disparities among patients with endometrial carcinoma have been previously reported. The objective of this study is to analyze and compare the molecular profiles in endometrial cancer in Caucasian and African American patients using a number of known molecular markers.

MATERIALS AND METHODS

147 patients diagnosed with endometrial cancer between 1995 and 2001 were included in the study. Patients' demographics, clinical and pathological data were reviewed. Immunohistochemical staining for p53, VEGF, Ki-67 and HIF-1alpha was performed on tissue micro array sections. Tumors' expression of p53, VEGF, Ki-67, and HIF-1alpha was compared based on ethnicity and tumor type (Type I = endometrioid carcinomas and Type II = non-endometrioid carcinomas). Spearman's correlation and Fisher's Exact Tests were used for statistical analysis and Kaplan-Meier, log-rank and Cox regression were used for survival analysis.

RESULTS

97 patients were Caucasian and 50 patients were African American. The mean age was 62 (33-91) years for Caucasian patients and 63.5 (24-89) years for the African American patients. African American patients had more Type II carcinoma than Caucasian patients (P = 0.055). High p53 expression was statistically significant among the African American patients (49% vs. 30%, P = 0.035) versus Caucasian patients. There was no significant difference demonstrated when comparing the VEGF, Ki-67, and HIF-1alpha expression between the racial groups. Survival analysis showed a trend toward a shorter survival in the African American patients compared to the Caucasian patients; median survival 62 versus 77 months (P = 0.061). On the other hand, we did not find a significant difference in survival by ethnicity when we adjusted for tumor histology.

CONCLUSION

While African American patients with endometrial cancer seem to show a trend toward a shorter survival, this seems to be mainly due to the fact that they have a higher proportion of Type II tumors. The molecular profiles for p53, Ki-67, VEGF and HIF-1alpha expression of histologically matched tumors were similar between the two ethnic groups.

[Human brucellosis. Retrospective studies of 63 cases in Lebanon]

OBJECTIVES

We performed an epidemiological survey to ascertain the clinical features of brucellosis in Lebanon.

PATIENTS AND METHODS

Between 1994 and 1998, 63 patients were seen at the Hôtel-Dieu de France Hospital in Beirut Lebanon. Diagnostic criteria were brucellar agglutinins at a titer > or = 1/160 with symptoms suggestive of brucellosis in the absence of another diagnosis. We also conducted a survey in 1138 cases registered by the Ministry of Health during the same period.

RESULTS

Among the 1137 cases, 40% of the patients were over 60 and only 16% were under 14. The overall male to female ratio was 1.01 and 69% of the patients were seen in spring and summer. Among the 63 patients, 10 were pediatric cases. The disease was acute in 41 (65%), subacute in 21 (33%) and chronic in 1. The main presenting symptoms were fever, sweating, easy fatigability and joint pain. Osteoarticular involvement was the most prevalent complication (25%), predominantly spondylitis. Among the blood tests, relative lymphocytosis was significantly more frequent in children than adults (80% versus 13%, p < 0.001).

CONCLUSION

Brucellosis is still an endemic disease in Lebanon and should be considered notably in patients presenting with prolonged fever, and articular and neurological manifestations.

Technique for replacing the mitral valve with a pulmonary autograft: the Ross-Kabbani operation

Replacing the mitral valve with a pulmonary autograft is an important option at the disposal of surgeons working in areas where lifelong anticoagulation is impractical. In this article we describe the technique of this operation as it has evolved through our experience with 51 patients operated on since July 1997.

Use of the pulmonary autograft for mitral replacement: short- and medium-term experience

OBJECTIVES

In an effort to find a suitable mitral substitute for our young rheumatic patients who cannot follow a proper anticoagulation regimen for life, we resorted to an old concept reported by one of the authors (D.N.R.) in 1967. This report summarizes our experience with the Ross-mitral operation to date.

METHODS

Between 19 June 1997 and 27 June 2000, 43 patients with rheumatic valve disease underwent the Ross-mitral operation. Two patients were excluded because of graft stenosis detected at the end of the procedure for which the autograft had to be sacrificed. Of the remaining 41 patients 29 were female, and the age range was 12--57 years (median 39 years). The autograft was incorporated within a Dacron tubing, with a pericardial collar attached to its proximal end. The conduit was sutured distally to the excised mitral annulus; the pericardium was attached proximally to the atrial wall in 36 patients, and was used simply to cover the Dacron tubing in five patients. The pulmonary artery was replaced with a pulmonary or aortic homograft, or with a pulmonary xenograft.

RESULTS

There were two hospital fatalities from a cerebrovascular accident and a lung injury, and two postoperative myocardial infarctions. There were five late deaths, two due to bacterial endocarditis, one due to excessive bleeding at reoperation for a paravalvular leak, and two not related to the procedure. A phenomenon of 'autograft stenosis' occurred intraoperatively in four recent consecutive patients that probably resulted from our use, for the first time, of softer Dacron tubing material. This was repaired in two of the four patients. Echocardiography confirmed excellent functioning of all 34 autografts of surviving patients up to 36 months postoperatively (mean follow-up 18.2 months). Two patients remain in functional Class III status, one due to left heart failure following myocardial infarction, and the other due to recurrent tricuspid insufficiency.

CONCLUSIONS

We believe that the mitral pulmonary autograft is a worthwhile alternative to mechanical prostheses in developing countries.

The mitral pulmonary autograft: a follow up cautionary report

BACKGROUND AND AIM OF THE STUDY

The study aim was to alert surgeons embarking on mitral replacement with the pulmonary autograft to the possibility of graft stenosis resulting from kinking of the Dacron tube support.

METHODS AND RESULTS

After having used old-style Dacron tubing for pulmonary autograft support in 32 patients, a change was made to a softer variety. This, together with routine retention of the posterior subvalvular apparatus, resulted in Dacron tube angulation and autograft stenosis detected at intraoperative echocardiography in four consecutive patients, This sequela was corrected in one patient by re-adjusting the pericardial collar, and in another by severing the retained chordae. However, in two patients it was necessary to sacrifice the autograft and replace it with a mechanical prosthesis. When the reason for the complication was identified, and a return to the use of a firmer Dacron material instigated, this phenomenon disappeared and surgery was completed in the final three patients, without mishap.

CONCLUSION

The use of a newer soft Dacron tubing to support the pulmonary autograft in mitral replacement might result in autograft stenosis. Thus, a firm-type Dacron should be used for this operation.

Early experience with left ventricular volume reduction surgery in Syria

OBJECTIVE

To review our early experience with left ventricular volume reduction surgery (the Batista operation) in the management of patients with end-stage heart failure.

METHODS

Between December 1996 and April 1998, 10 patients (9 males, mean age 32yr) with advanced symptomatic cardiomyopathy underwent left ventricular volume reduction surgery at Damascus University Cardiovascular Surgical Center. The cause of cardiomyopathy was idiopathic in three patients, valvular in four, ischemic in two, and viral myocarditis in one patient. Concomitant procedures included aortic valve replacement in four patients, mitral valve repair in six patients, and coronary artery bypass grafting in two patients.

RESULTS

All patients survived the procedure. Echocardiography prior to discharge documented significant improvement in ejection fraction in all but two patients. Mean follow-up was 7.6 months. After discharge, three patients developed progressive congestive heart failure to which they subsequently succumbed, and two more patients died suddenly late postoperatively. Only two patients continue to show both clinical and echocardiographic evidence of improvement.

CONCLUSION

Left ventricular volume reduction surgery cannot be freely advocated until better means are found to identify patients who will benefit from the procedure, and proper prophylaxis against fatal postoperative complications can be afforded.

A case of a large coronary artery fistula in an elderly patient surgically corrected 12 years after initial diagnosis

This case report discusses the natural history of a large coronary artery fistula in an elderly patient treated conservatively for 12 years. There has been no previous report of long term follow-up in a patient with a large coronary artery fistula with symptoms of congestive heart failure. The surgical management and clinical response to surgical correction will be discussed, and an extensive review of the literature will be performed.

Mitral valve replacement with a pulmonary autograft: initial experience

BACKGROUND AND AIM OF THE STUDY

For long-term substitution of the mitral valve, mechanical prostheses require life-long anticoagulation which is impractical in developing countries, xenografts degenerate early in our young population, and mitral homografts have not yet been established as being suitable. We therefore returned to an original concept first reported by one of the authors (D.N.R.) in 1967.

METHODS

Between July 1997 and November 1998, 22 patients (mean age 40.3 years; range: 28 to 57 years) with rheumatic mitral valve disease unsuitable for reconstruction were subjected to excision of their pulmonary valve in the standard fashion of the Ross procedure. The inverted autograft was incorporated in a 2.5 cm-long Dacron conduit, with a pericardial collar attached to its proximal end. The distal end of the autograft-conduit was sutured to the annulus of the excised mitral valve, and the proximal end incorporating the pericardial collar was attached to the adjacent atrial wall. In this way all prosthetic material was covered. The right ventricular outflow was reconstructed with a pulmonary homograft in 17 patients, with an aortic homograft in two, and with a porcine pulmonary xenograft in three.

RESULTS

One patient developed a fatal cerebrovascular accident, probably related to an incorrectly placed pericardial collar with rough surface exposed to the blood flow. In a second patient the autograft had to be replaced six weeks after operation due to bacterial endocarditis contracted in the operating room. Echocardiography confirmed excellent function of the remaining autografts up to 16 months postoperatively (mean follow up 8.3 months).

CONCLUSIONS

We believe the pulmonary autograft to be a valid option for mitral valve replacement in our patients.

Effects of sulfonamides on a metabolite-regulated ATPi-sensitive K+ channel in rat pancreatic B-cells

Intracellular ATP (ATPi)-sensitive K+ [K+(ATP)] channels are now a recognized site of action of clinically useful hypoglycemic and hyperglycemic sulfonamides. We have further examined the action of these agents on single K+ channels in rat pancreatic B-cells 1) Tolbutamide and glyburide, two hypoglycemic sulfonylureas which decrease K+(ATP) channel activity in the cell-attached patch, affect the kinetics of K+(ATP) channel in a manner similar to glucose. They shorten the duration of the "burst," or cluster of open channel events, while lengthening the intervals between bursts. 2) The hyperglycemic vasodilator diazoxide increases mean K+(ATP) channel activity in the cell-attached patch as well as in the inside-out excised patch exposed to ATPi. It appears to lengthen channel bursts and shorten the intervals between them. Two structurally similar diuretics, hydrochlorothiazide and furosemide, which have mild hyperglycemic effects, do not increase K+(ATP) channel activity even at clinically toxic concentrations. 3) Neither the sulfonylureas nor diazoxide directly affect the activity of single delayed rectifier K+ channels or single calcium and voltage-activated K+ channels in normal B-cells.