Silicone-based simulation models for peripheral nerve microsurgery

Background

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the “gold standard” of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons.

Volume control associated with better cardiac function in long-term peritoneal dialysis patients.

BACKGROUND: This study was undertaken to investigate the effect of long-term blood pressure (BP) reduction, achieved with salt restriction and strict volume control, on frequency and regression of left ventricular hypertrophy (LVH) in long-term peritoneal dialysis (PD) patients. METHODS: 56 patients who had been treated for more than 2 years under our care were enrolled. After echocardiographic (Echo) evaluation, 46 patients were included in the follow-up study. In our unit, we aim to keep patients' BP below 130/85 mmHg and cardiothoracic index below 0.50. To reach these targets, moderate salt restriction is advised, and if necessary, hypertonic PD solutions are used. Echo was performed at the beginning of the study (after a mean period of 36 months on PD) and at the end of the prospective follow-up period (24 months later). RESULTS: At the time of the first Echo, LVH was detected in only 8 (21%) patients. Residual urine volume was significantly decreased compared to data taken when they first started PD (658 +/- 795 vs 236 +/- 307 mL/day). Mean left ventricular mass index (LVMI) was 107 +/- 26.5 g/m2. LVMI was significantly decreased at the end of the follow-up in patients who had LVH at baseline. No LVH developed in patients who had normal LVMI at baseline. CONCLUSION: Our results indicate that control of hypertension is possible when extracellular fluid volume is kept under control using hypertonic PD solutions in case of recruitment in addition to salt restriction in long-term PD patients. Sustained normovolemia is associated with low incidence and regression of LVH.     

The problems and advantages of one lung ventilation during surgical intervention in pulmonary hydatid cyst disease

Background Hydatid disease is the most severe helminthic zoonosis, with an important public health problem especially in rural areas in Turkey. The aim of this study was to review the problems and advantages encountered in surgical treatment of 43 patients who were ventilated with one-lung ventilation during last four years. Methods Patients, operated with one-lung ventilation, constitute the study group. Data related to symptoms, radiographic findings, performed surgical procedures, perioperative and postoperative morbidity, hospitalization time, and cyst recurrence were collected from each individual's records. Results Cystotomy and capitonnage were performed in all cases. Perioperative complications were seen in 5 patients. Four of these 5 patients had double-lumen endotracheal tube malpositioning. In one patient hypoxemia developed. The most common postoperative complication was atelectasis. One patient had recurrent cysts. There was no perioperative or postoperative death. Conclusions We prefer cystotomy and capitonnage because it is a fast and effective technique with limited postoperative complications. One-lung ventilation prevents the exposure of lower lung areas from massive aspiration, which may cause acute obstruction of airways, and contamination by cyst contents from the operative part of the lung that causes recurrent disease. One-lung ventilation in pulmonary hydatid cyst surgery may be preferred owing to lower mortality and morbidity rates.     

Multiple primary malignant neoplasms in urologic patients

Methods: Second primary cancers constitute approximately 9–10% of malignancies diagnosed in the United States. We aimed to show the risk and incidance of second primary tumor occuring associated to urologic tumors and show the distrubution of tumors in Tracia region. We retrospectively examined the patients' files with the diagnosis of malignant disease between the years 1985–2000. Hazard function analysis was performed to estimate the relative risk of secondary malignancy occuring. Age, sex and tumor number were examined to find out if they affect on mortality rate. Results: A total number of 25 MPMNs were diagnosed. In 52 percent of the cases the second primary neoplasm developed within six months. The relative risk of development of a second neoplasm is found as increasing 1.111 times per month. The incidence of secondary malignancy occuring in the patients with one tumor was found as 6.31%. Age (p < 0.001) and tumor number (p < 0.001) are found as statistically effective predictor on mortality rate where the sex is not. Conclusions: In the patients with a primary tumor not only the metastasis must be investigated but also second primary tumors should be taken in to consideration. This revised version was published online in August 2006 with corrections to the Cover Date.     

Polyester film strips coated with photographic gelatin containing immobilized glucose oxidase hardened by chromium(III) sulphate.

Glucose oxidase was immobilized into photographic gelatin hardened by chromium(III) sulphate. The enzyme-gelatin mixture was coated on polyester film strips which allowed easy and simple handling during assays. The effect of gelatin and cross-linker concentrations on water content and enzymatic activity was studied. The effect of pH during immobilization and that of incubation temperature on maximum activity were examined. Enzyme leakage tests were carried out during reuse number studies. Consecutive use of strips followed by washing and resting between uses were found to affect the reuse number. A maximum immobilization of 68% was reached under optimal conditions. Mechanical stability and leakage were found to be functions of gelatin and cross-linker concentrations. Photographic gelatin was found to have many capabilities with extraordinary characteristics as a carrier on immobilization.     

Recurrent retroperitoneal cystic lymphangioma

Retroperitoneal cystic lymphangioma is a rare congenital malformation. The majority of lymphangiomas are present at birth and nearly all present before the age of two years. We report a case of giant cystic retroperitoneal lymphangioma in a patient who first presented with symptoms at the age of 7, underwent surgery, and who then suffered a recurrent mass 11 years later.     

A rapid method of genomic array analysis of scaffold/matrix attachment regions (S/MARs) identifies a 2.5-Mb region of enhanced scaffold/matrix attachment at a human neocentromere

Human neocentromeres are fully functional centromeres that arise at previously noncentromeric regions of the genome. We have tested a rapid procedure of genomic array analysis of chromosome scaffold/matrix attachment regions (S/MARs), involving the isolation of S/MAR DNA and hybridization of this DNA to a genomic BAC/PAC array. Using this procedure, we have defined a 2.5-Mb domain of S/MAR-enriched chromatin that fully encompasses a previously mapped centromere protein-A (CENP-A)-associated domain at a human neocentromere. We have independently verified this procedure using a previously established fluorescence in situ hybridization method on salt-treated metaphase chromosomes. In silico sequence analysis of the S/MAR-enriched and surrounding regions has revealed no outstanding sequence-related predisposition. This study defines the S/MAR-enriched domain of a higher eukaryotic centromere and provides a method that has broad application for the mapping of S/MAR attachment sites over large genomic regions or throughout a genome.     

Preoperative embolization in surgical treatment of a primary hemangiopericytoma of the rib: a case report

Primary hemangiopericytoma of the rib is extremely rare and only a few cases have been reported. A 62-yr-old man presented with an aching chest pain and dyspnea. Thoracic computed tomography revealed a homogenous mass expanding the right seventh rib. A diagnosis of hemangiopericytoma was established by percutaneous needle biopsy. Preoperative embolization of the feeding vessels of the tumor was performed in order to prevent perioperative bleeding. There was no significant bleeding during the surgery, where complete resection of the tumor with 7th to 9th ribs with a surgical margin of 5 cm was performed. Postoperative course was uneventful and there has been no recurrence for thirteen months. To our knowledge, there has been no report to apply a preoperative embolization of a primary hemangiopericytoma of the rib.     

Neuraminidase produces a decrease of adherence of slime-forming <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> to gelatin-impregnated polyester fiber graft fabric: an experimental study

Because slime-forming microorganisms are the major causative agents of graft infections, we aimed to investigate bacterial adherence in slime-forming and nonslime-forming Staphylococcus aureus and to determine the role of neuraminidase (NANase) on adherence to gelatin-impregnated polyester fiber graft fabric. An in vitro model was developed to quantitatively measure bacterial adherence to the surface of the graft. The grafts were divided into two groups – those colonized with slime-forming S. aureus and those colonized with nonslime-forming S. aureus. The grafts were put into sterile tubes and human plasma was instilled and incubated at 37°C to perform fibrin deposition on the grafts. After 48 h of incubation, grafts were drained and inoculated with slime-forming or nonslime-forming S. aureus in triptic soy broth in the presence or absence of NANase. Following 36 h of incubation at 36°C, grafts were vortexed and cultured to perform a colony count. Bacterial counts were expressed as total colony-forming units per square centimeter of graft. Slime-forming S. aureus had greater affinity with the graft compared with nonslime-forming S. aureus (P < 0.05). The adherence of slime-forming S. aureus was impaired by NANase treatment (P < 0.001) but NANase treatment of nonslime-forming S. aureus did not change the adherence to the graft (P > 0.05). These results show that slime plays an important role in the pathogenesis of vascular graft infection. Adherence of slime-forming S. aureus can be decreased by NANase treatment. This may have implications for the development of neuraminidase-embedded vascular grafts to diminish biomaterial-related infections.