Biomedical subjects
Publications and source records attributed to A Sarkis.
The usefulness of three-dimensional angiography is not fully established except for neurovascular diseases. We report a case of significant renal artery stenosis not shown on conventional angiography because of its orientation along the axial plane, where 3D imaging allowed complete analysis of the lesion leading to endovascular treatment.
The incidence of postoperative atrial fibrillation in cardiac surgery is still high despite major advances in anesthetic, pharmacological and surgical techniques. Its precise mechanism is still totally unknown. Postoperative atrial fibrillation increases length of stay as well as hospital costs. Rate of postoperative atrial fibrillation spontaneous conversion is high. Several protocols have been developed for prevention and/or treatment of postoperative atrial fibrillation. Beta-blockers, amiodarone and atrial pacing reduce.atrial fibrillation incidence as compared to placebo. On the other hand, amiodarone and propafenone achieve a high conversion rate of installed postoperative atrial fibrillation. However, among many pharmacological options, the best treatment is still to be defined.
Considerable evidence has accumulated over the last decade implicating a role of cytochrome P450 (CYP)-dependent metabolites of arachidonic acid (AA) in the pathogenesis of hypertension. Indeed, 20-hydroxyeicosatetraenoic acid (20-HETE) is produced by vascular smooth muscle (VSM) cells and is a potent vasoconstrictor that depolarizes VSM by blocking large conductance Ca+-activated K2+ channels. In contrast, epoxyeicosatrienoic acids (EETs) are synthesized by the vascular endothelium and have opposite effects on VSM (hyperpolarization and vasodilatation). Inhibition of the synthesis of 20-HETE attenuates myogenic tone and autoregulation of blood flow and modulates vascular responses to vasodilators (NO and CO) and vasoconstrictors (angiotensin II, endothelin). In the kidney, 20-HETE inhibits sodium transport in the proximal tubule by blocking Na+-K+-ATPase activity. In the thick ascending limb of the loop of Henle, 20-HETE inhibits Na+-K+-2Cl- transport, in part, by blocking a 70 pS apical K+ channel. EETs are produced in the proximal tubule where they inhibit Na+-H+ exchange and in the collecting duct where they inhibit sodium and water transport. Numerous studies have established that the formation of EETs and 20-HETE and the expression of CYP enzymes are altered in the kidney in many genetic and experimental animal models of hypertension and in some forms of human hypertension. However, the functional significance of these changes remains to be determined. Given the importance of this pathway in the control of renal function and vascular tone, it is likely that alterations in the renal formation of CYP-dependent metabolites of AA will be shown to participate in the development of hypertension in many of these models.
This article reports the use of gadolinium to perform a coronarography in a patient with renal insufficiency, unstable angina, and peripheral vascular disease. The examination was well tolerated and the images obtained of good quality. Cathet Cardiovasc Intervent 2001;54:68-69.
Cardiac echinococcosis is rare despite endemic occurrence of echinococcosis in some regions of the world. Clinical presentation can vary and may be misleading. Diagnosis is facilitated by new imaging techniques. Surgery is mandatory to avoid serious complications. We report a case of cardiac echinococcosis with pseudo, ischemic clinical and electrical presentation.
BACKGROUND: The decline in circulating oestrogen around the time of the menopause often induces unacceptable symptoms that affect the health and well being of women. Hormone replacement therapy (both unopposed oestrogen and oestrogen and progestogen combinations) is an effective treatment for these symptoms. In women with an intact uterus, unopposed oestrogen may induce endometrial stimulation and increase the risk of endometrial hyperplasia and carcinoma. The addition of progestogen reduces this risk but may cause unacceptable symptoms, bleeding and spotting which can affect adherence to therapy. OBJECTIVES: The objective of this review is to assess which hormone replacement therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma with a low rate of abnormal vaginal bleeding. SEARCH STRATEGY: Electronic searches for relevant randomised controlled trials of the Cochrane Menstrual Disorders and Subfertility Group Register of Trials, MEDLINE, EMBASE, PsychLIT, Current Contents, Biological Abstracts, Social Sciences Index and CINAHL were performed. Attempts were also made to identify trials from citation lists of review articles and drug companies were contacted for unpublished data. In most cases, the corresponding author of each included trial was contacted for additional information. SELECTION CRITERIA: The inclusion criteria were randomised comparisons of unopposed oestrogen therapy, combined continuous oestrogen-progestogen therapy and sequential oestrogen-progestogen therapy with each other and placebo administered over a minimum treatment period of six months. Trials had to assess which regimen was the most protective against the development of endometrial hyperplasia/carcinoma and/or caused the lowest rate of irregular bleeding. DATA COLLECTION AND ANALYSIS: Twenty three RCTs were identified and five were excluded. The reviewers assessed the eighteen included studies for quality, extracted the data independently and odds ratios for dichotomous outcomes were estimated. Outcomes analysed included frequency of endometrial hyperplasia or carcinoma, frequency of irregular bleeding and unscheduled biopsies or dilation and curettage, and adherence to therapy. MAIN RESULTS: Unopposed moderate or high dose oestrogen therapy was associated with a significant increase in rates of endometrial hyperplasia with increasing rates at longer duration of treatment and follow up. Odds ratios ranged from 5.4 (1. 4-20.9) for 6 months of treatment to 16.0 (9.3-27.5) for 36 months of treatment with moderate dose oestrogen (in the PEPI trial, 62% of those who took moderate dose oestrogen had some form of hyperplasia at 36 months compared to 2% of those who took placebo). Irregular bleeding and non adherence to treatment were also significantly more likely under these unopposed oestrogen regimens with greater effects with higher dose therapy. There was no evidence of increased hyperplasia rates, however, with low dose oestrogen. The addition of progestogens, either in continuous combined or sequential regimens, helped to prevent the development of endometrial hyperplasia and improved adherence to therapy (odds ratios of 3.7 for sequential therapy and 6.0 for continuous therapy). Irregular bleeding, however, was more likely under a continuous than a sequential oestrogen-progestogen regimen (OR = 2.3, 95% CI 2.1-2.5) but at longer duration of treatment, continuous therapy was more protective than sequential therapy in preventing endometrial hyperplasia (OR = 0.3, 95% CI 0.1-0.97). There was evidence of a higher incidence of hyperplasia under long cycle sequential therapy (progestogen given every 3 months) compared to monthly sequential therapy (progestogen given every month). No increase in endometrial cancer was seen in any of the treatment groups during the limited duration (maximum of 3 years) of these trials. (ABSTRACT TRUNCATED)
The autocrine/paracrine interaction of the epidermal growth factor receptor (EGFr) and transforming growth factor alpha (TGF-alpha) has been implicated in prostate cancer cell growth and proliferation. To evaluate the role of EGFr and TGF-alpha in prostate cancer progression, we studied the immunohistochemical staining pattern of EGFr and TGF-alpha in malignant primary and hormone-independent metastatic prostate lesions. The specimens evaluated included 37 primary carcinomas (34 hormone-naive and 3 hormone-refractory tumors) and 22 metastases. For each specimen, the pattern of expression was evaluated and staining reactivities graded from 0-3, with 0 representing no staining and 3 representing homogeneous and intense staining. Primary malignant prostate epithelial cells in areas with discrete gland formation showed strong EGFr immunostaining, while stromal cells were generally nonreactive. In untreated primary tumors, TGF-alpha expression was primarily in the stroma, while epithelial cells were weakly positive in several cases. Malignant epithelial cells adjacent to neural elements that stained positive for TGF-alpha was frequently observed. A homogeneous staining pattern for EGFr was noted in 17 (89%) of 19 evaluable androgen-independent-refractory metastases, while TGF-alpha expression was found in 14 (78%) of 18 evaluable cases. Overall, 14 of 18 androgen-independent metastases coexpressed the receptor and the ligand. These results suggest that, unlike primary prostate tumors where a paracrine relationship between EGFr and TGF-alpha appears to predominate, the potential for autocrine stimulation may exist in the majority of metastatic androgen-independent tumors. Furthermore, the changing pattern of expression as the disease evolves from the localized hormone-naive to metastatic androgen-independent condition suggests that strategies aimed at blocking this growth factor pathway may be of therapeutic importance for androgen-independent disease.
PURPOSE: To determine survival in patients with muscle-invasive bladder cancer treated with neoadjuvant chemotherapy and to analyze prechemotherapy and postchemotherapy factors for prognostic significance. PATIENTS AND METHODS: The survival of 111 patients with T2-4N0M0 bladder cancer treated with neoadjuvant methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) was assessed. Prechemotherapy and postchemotherapy factors were analyzed for correlation with survival. Factors found to be significant on univariate analysis were subjected to multivariate analysis using Cox's proportional hazards model. RESULTS: The median follow-up duration was 5.3 years. Initial tumor (T) stage (P = .0001), presence of ureteral obstruction (P = .0074), and presence of a palpable mass (P = .0039) were the only pretreatment factors found to be significant on univariate analysis. Postchemotherapy surgery was performed in 81 patients. In these cases, postchemotherapy clinical stage and pathologic stage were significant factors on univariate analysis. In the multivariate analysis, the initial prechemotherapy T stage and the postchemotherapy pathologic stage (pT stage) were the only two factors to demonstrate independent significance. An association between downstaging postchemotherapy and survival was observed for patients with extravesical disease (T < or = 3B) at the start of treatment. In this subset, the 5-year survival rate was 54% for patients with downstaging versus 12% for those without downstaging. This association was not observed for patients with bladder-confined disease (T < or = 3A) at presentation. CONCLUSION: The stage of bladder cancer at presentation and at postchemotherapy pathologic staging are independent prognostic factors for long-term survival in patients treated with neoadjuvant chemotherapy. Downstaging after neoadjuvant chemotherapy was associated with improved survival in patients with muscle-invasive bladder cancers, but only for those with extravesical disease (T > or = 3B) pretreatment. Randomized comparisons will be required to assess the impact of chemotherapy on overall survival.
The success of thrombolytic therapy for acute myocardial infarction is limited by failure of reperfusing 25% of occluded arteries, bleeding complications in 0.4 to 1% of patients and the possibility of recurrent ischemia. These problems can be overcome by the use of immediate angioplasty without previous thrombolytic therapy. Between February and December 1993, twelve patients (ten men and two women) admitted for acute myocardial infarction were treated by immediate angioplasty. Five patients had a contraindication to thrombolysis and seven had angioplasty as a deliberate choice. Successful recanalisation was obtained in 11 patients (92%) with one reocclusion at 24 hours. Two patients admitted in cardiogenic shock 12 hours after the onset of symptoms died lately with multiorgan failure. Only one case of clinical restenosis was observed and was redilated. In conclusion, immediate angioplasty without prior thrombolytic therapy is a rapid method of revascularisation with minimal risk and good outcome when it is used early after acute myocardial infarction.
Cholesterol embolization sometimes occurs after invasive procedures involving manipulation of the aorta or its major branches, and less commonly occurs after thrombolytic therapy for acute myocardial infarction. Rarer still is spontaneous cholesterol embolization, a case of which we now report. Our patient experienced peripheral embolization, the origin of which was traced to the infrarenal aortic segment and the common iliac vessels. Aortoiliac reconstruction was successful; we believe that surgical management of this condition should be performed in selected cases.
A case of traumatic arteriovenous fistula and false aneurysm of the internal mammary artery was encountered following sternal wire insertion during cardiac surgery. The diagnosis was suspected by echo-doppler and confirmed by arteriography allowing percutaneous embolization using cyanoacrylate in the same setting.
An unusual instance of severe and potentially lethal depression of the bone marrow is described as a result of the administration of phenytoin for seizure prophylaxis. The patient was treated successfully by prompt cessation of phenytoin and intravenous administration of human recombinant granulocyte-macrophage colony-stimulating factor.
The authors report a case of surgical repair of total anomalous pulmonary venous connection in a 36-year-old male. This is a very rare disease in adulthood since over 80% of the infants die before one year of age. Fifty-two surgical cases were previously reported in the literature. An extensive review of these cases is presented. Surgery is the only treatment and offers excellent short- and long-term results.
Embolization of cholesterol crystals from atheromatous plaques is a rare entity most often seen after invasive procedures involving manipulation of the aorta. Spontaneous CE has been reported in very rare cases. Peripheral signs include livedo reticularis, muscle pain and palpable pulses. Depending on the site of the responsible plaque, emboli may involve visceral organs and produce a systemic illness. Diagnosis is confirmed using skin, muscle and/or renal biopsies. Surgery is recommended when the atheromatous disease is localized to a unique segment which can be replaced.
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Reports concerning unruptured, isolated aneurysms of one sinus of Valsalva are rare. These aneurysms usually protrude inside the heart and are very rarely extracardiac. We report 4 cases of isolated, unruptured extracardiac aneurysms of the noncoronary sinus of Valsalva. Clinical symptoms were nonspecific. Operation was performed by patch reconstruction of the dilated aortic sinus without replacement of the ascending aorta. Microscopic examination of the diseased aortic wall revealed absence of medial elastic fibers. Late follow-up in all 4 cases revealed a normal ascending aorta with no dilatation of the aortic root and no aortic regurgitation.
The authors report the case of a 17 year old patient operated for valvular aortic stenosis associated with severe hypertrophy of the interventricular septum. The operation consisted of aortic valve replacement and septal myectomy. Color-flow imaging in the postoperative period showed a coronary artery--left ventricular fistula in the region of the septal myectomy. In view of the small size of the fistula on echocardiographic examination and the absence of a codified strategy of management of acquired coronary left ventricular fistula after surgery, a simple Doppler echocardiographic follow-up was proposed in this case.
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