Thromboangiitis obliterans - case report.

Thromboangiitis obliterans (Buerger'€™s disease) represents an inflammatory disease of limbs'€™ small arteries and veins causing vascular thrombosis, and partial or total obstruction. It affects mostly male gender aged 40 years old. The peculiarity of our case is underlined by presenting a 62 years, chronic tobacco user and not compliant female patient known with thromb oangiitisobliterans for almost 15 years. The arteriographic and clinical features with concomitant and sever affected upper and lower limbs are highly suggestive, emphasizing the possibility of Buerger'€™s disease development even in female patients.

Erectile dysfunction post-radical prostatectomy - a challenge for both patient and physician.

Post-radical prostatectomy erectile dysfunction (post RP ED) is a major postoperative complication with a great impact on the quality of life of the patients. Until present, no proper algorithm or guideline based on the clinical trials has been established for the management of post RP ED. According to literature, it is better to initiate a penile rehabilitation program as soon as possible after surgery than doing nothing, in order to prevent and limit the postoperative local hypoxygenation and fibrosis. The results of numerous clinical trials regarding the effectiveness of the phosphodiesterase 5 inhibitors therapy on post RP ED have made them the gold standard treatment. Encouraging results have been achieved in studies with vacuum erectile devices, intraurethral suppositories with alprostadil and intracavernosal injections, but due to their side effects, especially in the cases of intracavernosal injections and intraurethral suppositories, their clinical use was limited therefore making them a second line option for the post RP ED treatment. What should not be forgotten is that penile implant prosthesis has proven very effective, numerous studies confirming high rates of satisfaction for both patients and partners.

Determining factors of diuresis in chronic kidney disease patients initiating hemodialysis.

BACKGROUND: Patients with stage 5 chronic kidney disease (CKD) begin chronic hemodialysis with variable diuresis levels correlated to a comparable low glomerular filtration rate. Residual diuresis influences long-term evolution of the hemodialyzed patient, modifying the prognosis even if optimal Kt/ V is achieved. AIM OF THE STUDY: The present study emphasizes the main determining factors of diuresis in a cohort of stage 5 CKD subjects at the beginning of hemodialysis. MATERIAL AND METHODS: 216 patients with stage 5 CKD starting chronic hemodialysis were included in the study, and were grouped according to their residual diuresis: group A (urine output ≤ 500 mL/ day); group B (urine output between 500-1200 mL/ day); group C (urine output ≥ 1200 mL/ day). RESULTS: Glomerular etiology, cardiac systolic dysfunction, severe malnutrition, emergency dialysis initiation and lack of permanent vascular access were proved to be associated with significant low diuresis. Age, gender, estimated glomerular filtration rate (GFR) and the presence of systemic hypertension did not influence the amount of daily diuresis. CONCLUSIONS: In CKD stage 5 patients, residual diuresis presents large variations in conditions of comparable low GFR. Factors influencing residual diuresis may be distinct from those that influence residual GFR.

A rare case of watermelon stomach in woman with continuous ambulatory peritoneal dialysis and systemic lupus erythematosus.

We report a case of a 42-year-old woman with systemic lupus erythematosus and chronic kidney disease stage 5 undergoing continuous ambulatory peritoneal dialysis, presenting asthenia, dizziness, abdominal pain and small efforts dyspnea. After a complete physical and clinical examination, including laboratory tests, esophagogastroduodenal endoscopy and gastric lesions biopsy, she was diagnosed with gastric antral vascular ectasia. We are facing a rare case of antral vascular ectasia in a patient associating both chronic kidney disease and autoimmune disease.

Correlation between albuminemia, natremia and survival rates in patients with hepatorenal syndrome.

A two years prospective study was developed, based on the monitoring of 84 patients with cirrhosis and elevated serum creatinine; 33 patients met the diagnostic criteria for the hepatorenal syndrome. In these 33 patients, survival rate has been studied in correlation with hepatorenal syndrome types, serum albumin and natremia.

Timing-jitter reduction in a fiber laser mode locked by an input bit stream.

We present analytical and numerical results for the amount of timing-jitter reduction obtained in an all-optical clock-recovery device in which a data stream is used to mode lock a fiber laser through cross-phase modulation. This situation is analyzed when the laser pulses are close to optical solitons, so the effect of the data stream on the laser pulses is predicted from soliton perturbation theory. In our numerical simulations, both periodic input and pseudorandom input data streams are considered. The results show that for both types of data the rms timing jitter in the recovered clock is reduced significantly from that present in the input data.

Pulse propagation in nonlinear-optical fibers with phase-locked phase-sensitive amplifiers.

Recently the use of periodically spaced, phase-sensitive optical parametric amplifiers was proposed for compensating for linear loss in a nonlinear fiber-optic communication line [Opt. Lett. 18, 803 (1993)]. In the previous analysis, in which the stability of a single pulse was investigated, the variation of the amplifier phases was neglected. In a physically realizable line, however, the phase of each amplifier would most likely be locked to the phase of the signal pulse or to the average of the phases of many such pulses. Here an analysis is presented in which the amplifier phase is allowed to vary in response to a signal pulse's optical phase. The analysis shows that the solitonlike signal pulses remain stable even with this additional phase variation.

Soliton collisions with wavelength-division multiplexed systems with strong dispersion management.

We investigate collisions between solitons in a lossless two-channel wavelength-division multiplexed system with strong dispersion management. Numerical results show that the net frequency shift that is due to interchannel collisions is at least 1 order of magnitude smaller than predicted by adiabatic theories. A modified theoretical analysis is presented and shown to be in good agreement with the numerical results.

Double prenylation by RabGGTase can proceed without dissociation of the mono-prenylated intermediate.

Rab geranylgeranyltransferase (RabGGTase) catalyzes the prenylation of Rab proteins. Despite possessing a single active site, RabGGTase is able to add geranylgeranyl moieties onto each of the two C-terminal cysteine residues of Rab. We have studied the kinetics of Rab double prenylation employing a combination of a novel high pressure liquid chromatography (HPLC)-based in vitro prenylation assay and fluorescence spectroscopy. Transfer of the first geranylgeranyl group proceeds with a k(1) = 0.16 s(-1), while the conversion from singly to double prenylated Rab is 4-fold slower (k(2) = 0.039 s(-1)). We found that following the first transfer reaction, the conjugated lipid is removed from the active site of RabGGTase but mono-prenylated Rab.REP complex remains bound to RabGGTase with a K(d) < 1 nm. In contrast to the doubly prenylated Rab7.REP dissociation of the mono-prenylated species from RabGGTase was only weakly stimulated by phosphoisoprenoid. Based on the obtained rate constants we calculated that at least 72% of mono-prenylated Rab molecules proceed to double prenylation without dissociating from RabGGTase. The obtained data provides an explanation of how RabGGTase discriminates between mono-prenylated intermediate and double prenylated reaction product. It also indicates that the phosphoisoprenoid acts both as a substrate and as a sensor governing the kinetics of protein.protein interactions in the double prenylation reaction.

Soliton collisions in dispersion-managed wavelength-division-multiplexed systems.

We show that collision-induced frequency shifts in wavelength-division-multiplexed (WDM) soliton transmission systems are strongly suppressed with increasing dispersion management. We predict new oscillations in the residual frequency shift response, owing to the relative motion induced by the dispersion map, and demonstrate a direct correlation between these oscillations and the modified soliton-collision dynamics. Simple analytical expressions for the oscillation minima are obtained, and implications for WDM soliton system design are discussed.

10-Gbit/s dispersion-managed soliton transmission over 16,500 km in standard fiber by reduction of soliton interactions.

We show experimentally and numerically that in high-speed strongly dispersion-managed standard fiber soliton systems nonlinear interactions limit the propagation distance. We present results that show that the effect of these interactions can be significantly reduced by appropriate location of the amplifier within the dispersion map. Using this technique, we have been able to extend the propagation distance of 10-Gbit/s 2(31)-1pseudorandom binary sequence soliton data to 16, 500 km over standard fiber by use of dispersion compensation. To our knowledge this distance is the farthest transmission over standard fiber without active control ever reported, and it was achieved with the amplifier placed after the dispersion-compensating fiber in a recirculating loop.

Crystallization and preliminary X-ray diffraction analysis of the Rab escort protein-1 in complex with Rab geranylgeranyltransferase.

Posttranslational prenylation of proteins is a widespread phenomenon and the majority of prenylated proteins are geranylgeranylated members of the Rab GTPase family. Geranylgeranylation is catalyzed by Rab geranylgeranyltransferase (RabGGTase) and is critical for the ability of Rab protein to mediate vesicular docking and fusion of various intracellular vesicles. RabGGTase consists of a catalytic alpha/beta heterodimer and an accessory protein termed Rab escort protein (REP-1) that delivers the newly prenylated Rab proteins to their target membrane. Mutations in the REP-1 gene in humans lead to an X-chromosome-linked defect known as choroideremia--a debilitating disease that inevitably culminates in complete blindness. Here we report in vitro assembly and purification of the stoichiometric ternary complex of RabGGTase with REP-1 stabilized by a hydrolysis-resistant phosphoisoprenoid analog--farnesyl phosphonyl(methyl)phoshonate. The complex formed crystals of extended plate morphology under low ionic-strength conditions. X-ray diffraction data were collected to 2.8 A resolution at the ESRF. The crystals belong to the monoclinic space group P2(1), with unit-cell parameters a = 68.7, b = 197.7, c = 86.1 A, beta = 113.4 degrees. Preliminary structural analysis revealed the presence of one molecule in the asymmetric unit.