A genetic algorithm-based method for the mechanical characterization of biosamples using a MEMS microgripper: numerical simulations.

In this paper, the viscoelastic characterization of biosamples is addressed considering a measuring technique relying on the use of a MEMS techonology-based microgripper. A proper mechanical model is developed for the coupled nonlinear dynamics of the microsystem, composed of the measuring tool and the specimen to be analyzed. The Maxwell liquid drop model and the generalized Maxwell-Wiechert model are considered for the sample, and the identification of the viscoelastic parameters is performed by implementing a genetic algorithm.

Weekly and 3-weekly cisplatin concurrent with intensity-modulated radiotherapy in locally advanced head and neck squamous cell cancer.

In loco-regionally advanced head and neck squamous cell cancer (HNSCC), concurrent 3-weekly cisplatin improves overall survival (OS) compared to radiotherapy alone, but is often associated with renal toxicity. The use of radiotherapy with accelerated fractionation schedules has been reported to improve survival but its optimal combination with chemotherapy is unclear. Retrospective analysis of treatment outcome and nephrotoxicity of radiotherapy given with an intensity-modulated approach (IMRT) concurrent with either 3-weekly or weekly cisplatin in 94 patients with stage III/IV HNSCC. Patients treated with weekly cisplatin were significantly older (p=0.0014) and received a significantly lower total cisplatin dose (p=0.0002). With a median follow-up of 2.8 years, at univariate analysis, 3-weekly cisplatin shows a longer OS (p=0.041) but progression-free survival (PFS) is similar for both schedules (p=0.47). Cisplatin doses >240 mg/m(2) were associated with better OS but not PFS. Chronic renal failure rate was significantly higher with 3-weekly cisplatin (p=0.04). Multivariate analysis (Cox regression controlling for age) confirmed the significant and independent impact of alcohol and smoking habits on both PFS (HR, 2.2) and OS (HR, 2.3), while the treatment schedule affected only OS (HR, 2.2). Weekly cisplatin is less nephrotoxic. Both schedules can be combined to curative IMRT. PFS was not significantly different even if patients treated with the weekly schedule were significantly older and received reduced cisplatin doses. The study suggests that the different cisplatin dose doesn't affect the PFS results if concomitant to IMRT. Controlled prospective studies are needed.

Adjuvant radio-chemotherapy after extended or simple cholecystectomy in gallbladder cancer

PURPOSE: To analyse results of combined treatment of adjuvant radio-chemotherapy (RT-CT) in patients diagnosed with gallbladder cancer (GBC) after complete resection. METHODS AND MATERIAL: From June 1993 until July 2006, 67 patients with a diagnosis of GBC who underwent R0 surgical resection and were staged as T1b-2-3N0-1M0 received adjuvant RT-CT. Radiotherapy consisted of whole abdominal irradiation (20 Gy at 100 cGy daily) plus a boost to the tumour bed for a total of 45-59.4 Gy. Concomitant chemotherapy (fluoropyrimidines) was given. Overall survival (OS) and median survival were analysed in relation to different prognostic factors. RESULTS: With a median follow-up of 90 months, 5-year OS was 41%, in the group who underwent extended cholecystectomy it reached 57% and it was only 27% in those who underwent simple cholecystectomy (p = 0.005). Median survival was 42 months for the whole population, not yet reached for the extended cholecystectomy subgroup and 23 months for the simple cholecystectomy subgroup. When analysing for histological grade, median survival was 23 months for those graded as high grade (III or IV) and 57 months for those of low-unknown grade (p = 0.029). In multivariate analysis, a statistically significant OS benefit was found for those who underwent extended cholecystectomy (p = 0.003). CONCLUSIONS: In the absence of randomised studies, these data support the use of extended cholecystectomy followed by adjuvant RT-CT in patients diagnosed as stages T1b-2- 3N0-1M0 GBC after R0 resection (AU)

Individual effect of renin-angiotensin system inhibition and corticosteroid therapy in IgA glomerulonephritis: results of a pilot study.

BACKGROUND: The impact of different therapy modalities on the outcome of Immunoglobulin A glomerulonephritis (IgAGN) in individual patient is not clear. We present preliminary results from the sequential application of renin-angiotensin system (RAS) inhibition and corticosteroids to discriminate the individual effect of both therapies. METHODS: Regardless of the degree of proteinuria, renal function and histological grading, patients with biopsy-proven IgAGN were treated with a standardized protocol. RAS inhibition was performed for 3 months. Thereafter, immunosuppressive therapy with prednisone (0.5 mg/kg body weight) on alternate days for 6 months was started. The primary endpoint was a maximal reduction of proteinuria (spot urine protein/ creatinine ratio (uPCR)), by RAS inhibition and by the combination of RAS inhibition and steroids. RESULTS: 10 patients were treated according to the protocol. During a median follow-up of 18 months, uPCR decreased from initial 230 mg/mmol (2 g/g) (median, interquartile range (IQR) 146 - 396) to 154 mg/mmol (1.4 g/g) (IQR 88 - 190) at 3 months during the RAS inhibition period (33% reduction, p = 0.01) and further to 31 mg/mmol (0.3 g/g) (IQR 21 - 71) until end of the steroid period at 9 months (80% reduction compared to uPCR at 3 month, p < 0.001). At the last F/U, uPCR (median) remained stable at 41 mg/mmol (0.4 g/g). The estimated glomerular filtration rate was stable during the whole observation period. CONCLUSIONS: Sequential RAS inhibition and steroid treatment leads to a continuous decrease in proteinuria, beyond the decrease produced by isolated RAS inhibition. Our data suggest independent effects of both, RAS inhibition and steroids, on the reduction of proteinuria in a small, non selected group of patients with IgAGN. The hypothesis that patients with IgAGN, regardless of the degree of proteinuria, renal function and histological grading, may benefit from combination therapy with maximal RAS inhibition and low dose corticosteroids now has to be confirmed in a randomized study.

Continuous veno-venous hemofiltration with regional citrate anticoagulation: a four-year single-center experience.

BACKGROUND: Hemofiltration protocols using a citrate-buffered replacement solution offer the advantage of regional anticoagulation and a buffer effect. The role played by such fluids in clinical practice is not yet well established. The risk of electrolytic disorders, acid-base imbalance, or citrate accumulation should be clarified. We report on a renal therapy protocol based on a citrate isonatremic replacement solution. METHOD: We considered all patients needing renal replacement therapy admitted to our cardiovascular intensive care unit between January 2003 and June 2007. A citrate-buffered fluid was delivered in predilution mode to a post-filter ionized calcium target < or = 0.25 mmol/L. Extracorporeal blood flow was set at a constant of 140+/-10 ml/min. Blood calcemia was maintained by a 5% calcium-chloride solution infused into the patient. We recorded the patients' acid-base variables, ionized calcium, daily electrolytes, albumin, urea and filter life-span. RESULTS: We observed 101 consecutive patients out of 2,523; incidence 4%, overall mortality was 57% at ICU discharge. Mean replacement rate was 2,554+/-475 ml/h corresponding to 34+/-5 ml/kg/h. Mean patient ionized calcium level was 1.07+/-0.04 mmo/L, maintained by 13+/-2 ml/h of infused calcium-chloride. All other electrolytes remained in the normal range. The Stewart biophysical approach confirmed a strong anion gap of 3.1+/- 3 meq/L. Acid-base balance showed a buffer effect. Mean filter life-span was 52+/-11 h. CONCLUSION: Renal replacement therapy based on citrate-buffered fluid may be useful in clinical practice. This methodology presented an adequate metabolic control and allowed regional anticoagulation. A sufficient calcium supply was mandatory to avoid hypocalcemia. The small strong ion gap suggested a modest citrate accumulation.

High frequency vibration analysis by the complex envelope vectorization.

The complex envelope displacement analysis (CEDA) is a procedure to solve high frequency vibration and vibro-acoustic problems, providing the envelope of the physical solution. CEDA is based on a variable transformation mapping the high frequency oscillations into signals of low frequency content and has been successfully applied to one-dimensional systems. However, the extension to plates and vibro-acoustic fields met serious difficulties so that a general revision of the theory was carried out, leading finally to a new method, the complex envelope vectorization (CEV). In this paper the CEV method is described, underlying merits and limits of the procedure, and a set of applications to vibration and vibro-acoustic problems of increasing complexity are presented.

Surgical management of renal cell carcinoma during the second trimester of pregnancy.

Renal cell carcinoma is rarely diagnosed during pregnancy and its management represents a real challenge. Pregnancy demands special consideration in terms of diagnostic evaluation and management, particularly during the second trimester. We report a patient undergoing left radical nephrectomy using a thoracoretroperitoneal approach at 22 weeks' gestation. Histological analysis revealed a pT2R0G2 chromophobic renal cell carcinoma. Furthermore, we review the sparse literature available.

Retroperitoneoscopic living donor nephrectomy: a comparison with the open approach in respect of early postoperative pain management.

INTRODUCTION: We retrospectively compared perioperative donor outcomes and early postoperative pain control after retroperitoneoscopic (RLDN) and standard open (OLDN) living donor nephrectomy. METHODS: One hundred donors included fifty after RLDN (37 women/13 men) and 50 after OLDN (35 women/15 men) were retrospectively analyzed for basic analgesics, for opioid consumption, and for visual analog scale (VAS) to verify the experienced pain. The donors were questioned in the morning and evening of the first through fifth postoperative days. RESULTS: The mean age of both groups was equal. The mean operating time was 149.7 +/- 48.2 minutes (60 to 270) for RLDN and 164.1 +/- 30.3 minutes (60 to 240) for OLDN (P = NS). The mean warm ischemia time was 120 +/- 36 seconds (50 to 240) and 114 +/- 31 seconds (60 to 190) for the RLDN and OLDN groups, respectively (P = NS). The mean evening VAS for RLDN versus OLDN on postoperative days 1 to 5 was: 2.1 versus 2.2 (P = NS), 0.9 versus 1.8 (P = .009), 0.5 versus 1.3 (P = .016), 0.1 versus 0.7 (P = .013), and 0.1 versus 0.7 (P = .013), respectively. In both groups there was a tendency toward a higher VAS score in the morning than in the evening. RLDN donors showed significantly earlier period free of pain (VAS = 0) than those after OLDN. There was a significant difference of being free from any opiate between both groups after surgery. CONCLUSIONS: After RLDN donors experienced less postoperative pain than after OLDN over the early postoperative days. Therefore, postoperative regional anesthesia is not necessary for donors operated by a retroperitoneoscopic approach.

Sigmoid adenocarcinoma complicating ureterosigmoidostomy.

A 31-year-old man who died of metastatic adenocarcinoma of the sigmoid colon had undergone bilateral ureterosigmoidostomy for exstrophy of the bladder 20 years earlier. The patient never underwent a colonoscopy. Neoplastic transformation at the ureterosigmoid anastomosis must be considered as a possible severe complication, and therefore, periodic follow-up of these patients is mandatory.

[Treatment of Hodgkin's lymphoma]. / Tratamiento del linfoma de Hodgkin.

From November 1976 until September 1987, 59 patients with Hodgkin's disease have been admitted and treated with radiotherapy alone or radiotherapy plus elective chemotherapy after been staged according to Stanford's guidelines and following the Ann Arbor's classification. 33 patients were staged I or II, and 26 as stage III or IV. Patients in earlier stages received preferentially radiotherapy alone and those in more advanced stages received radio and chemotherapy. After a median follow-up of 39 months, 100% of patients in stage I, 81.5% of patients in stages II and III A and 45% of patients in stages III B and IV were alive and well. The relapse free survival for patients in stages II and III A was 48.4%, rising to 81.5% after rescue. The use of elective chemotherapy made no difference in survival for stages II B and III A.