Urethroplasty performed with an autologous urothelium-vegetated collagen fleece to treat urethral stricture in the minipig model.

INTRODUCTION AND OBJECTIVE: Tissue-engineered materials in urethral reconstructive surgeries are a promising field for innovative therapy. Collagen matrices increase stability of cell-based implants and can promote viability and proliferation of urothelial cells. In this study, a collagen type I-based cell carrier (CCC) with stratified multi-layer autologous urothelium was used for urethroplasty after induction of urethral stricture in eight minipigs. MATERIALS AND METHODS: Minipigs underwent surgical procedures to induce urethral stricture by thermocoagulation. Simultaneously, bladder tissue was harvested. Urothelial cells were expanded, labeled with PKH26 and seeded onto CCC in high density. 3 weeks after strictures were induced and verified by urethrography, minipigs underwent urethroplasty using the seeded CCC. Two animals were euthanized after 1, 2, 4, and 24 weeks. Urethras were histologically examined for integration and survival of seeded CCC. In vivo phenotype of multi-layered urothelium matrix constructs was characterized via immunofluorescence staining with pancytokeratin, CK20, p63, E-cadherin and ZO-1. RESULTS: Seeded CCCs showed excellent stability and suturability after manipulation and application. Transplanted cells were detected using positive PKH26 fluorescence up to 6 months after labeling. Urothelium matrix implants integrated well into the host tissue without sign of inflammation. Animals showed no sign of rejection or stricture recurrence (urethrography) at any time during experimental period. Immunofluorescence analysis confirmed epithelial phenotype, junction formation and differentiation after 2 weeks. CONCLUSION: CCC can be suitable for urologic reconstructive surgeries and represents a promising option for clinical application. Longer follow-up results are required to exclude re-occurrence of stricture reformation.

CT and 3-T MRI accurately identify T3c disease in colon cancer, which strongly predicts disease-free survival.

AIM: To compare the preoperative staging accuracy of computed tomography (CT) and 3-T magnetic resonance imaging (MRI) in colon cancer, and to investigate the prognostic significance of identified risk factors. MATERIALS AND METHODS: Fifty-eight patients undergoing primary resection of their colon cancer were prospectively recruited, with 53 patients included for final analysis. Accuracy of CT and MRI were compared for two readers, using postoperative histology as the reference standard. Patients were followed-up for a median of 39 months. Risk factors were compared by modality and reader in terms of metachronous metastases and disease-free survival (DFS), stratified for adjuvant chemotherapy. RESULTS: Accuracy for the identification of T3c+ disease was non-significantly greater on MRI (75% and 79%) than CT (70% and 77%). Differences in the accuracy of MRI and CT for identification of T3+ disease (MRI 75% and 57%, CT 72% and 66%) and N+ disease (MRI 62% and 63%, CT 62% and 56%) were also non-significant. Identification of extramural venous invasion (EMVI+) disease was significantly greater on MRI (75% and 75%) than CT (79% and 54%) for one reader (p=0.029). T3c+ disease at histopathology was the only risk factor that demonstrated a significant difference in rate of metachronous metastases (odds ratio [OR] 8.6, p=0.0044) and DFS stratified for adjuvant therapy (OR=4, p=0.048). CONCLUSION: T3c or greater disease is the strongest risk factor for predicting DFS in colon cancer, and is accurately identified on imaging. T3c+ disease may therefore be the best imaging entry criteria for trials of neoadjuvant treatment.

Early sacral neuromodulation prevents urinary incontinence after complete spinal cord injury.

BACKGROUND: The study aim was to investigate potential influences on human nerves and pelvic organs through early implantation of bilateral sacral nerve modulators (SNMs) in complete spinal cord injury (SCI) patients during the acute bladder-areflexia phase. METHODS: Ten patients with neurologically-confirmed complete spinal cord lesions (SCLs) were provided with bilateral SNMs during the phase of atonic-detrusor muscle. Modulation was achieved by two electrodes implanted into each S(3)-foramen. Six patients declined and served as controls. The mean follow-up was 26.2 months. RESULTS: Videourodynamics (VU) confirmed detrusor acontractility, resulting in urinary continence as well as significant reductions in urinary tract infections (UTIs). Bowel movements did not require oral laxatives; additional preprogrammed parameters achieved erections for intercourse. INTERPRETATION: Early SNM implantation in SCI patients may revolutionize neurogenic lower urinary tract (LUT) dysfunction management; it prevented detrusor overactivity and urinary incontinence, ensured normal bladder capacity, reduced UTI rates, and improved bowel and erectile functionality without nerve damage. CONCLUSION: Future SCI investigations will be conducted to evaluate the potential benefits of even earlier SNM placement to progressively enhance pelvic organ functionality. This new approach may provide important clues required for assessing whether neuronal information is passed through the sympathetic trunk ganglion to the brain after complete SCI. Further investigations are needed to determine if functional magnetic resonance imaging (fMRI) might be helpful for analyzing changes in brain function in patients with SNMs and those taking antimuscarinics.

Distribution of mesorectal lymph nodes in rectal cancer: in vivo MR imaging compared with histopathological examination. Initial observations.

The aim of this work was to determine the distribution of mesorectal lymph nodes using T2-weighted magnetic resonance (MR) imaging compared with histopathological findings in patients with rectal carcinoma. Sixteen patients with rectal carcinoma undergoing primary surgery without pre-operative neoadjuvant treatment were evaluated using 3-mm axial T2-weighted MR imaging. The position of each visible mesorectal node on imaging was localised by measuring its minimum distance from the mesorectal fascia (d(m)), its minimum distance from the rectal wall (d(r)) and its distance from the distal tumour margin (d(v)). Independent assessment of d(m), d(r) and d(v) was made at histopathological examination. Eighty-five mesorectal nodes on in vivo MR imaging were matched to histopathological findings. On imaging, 67/85 mesorectal nodes were found at the level of the tumour and 84/85 were identified at or within 5 cm proximal to the tumour. Only one out of 85 nodes was seen below the inferior tumour margin. The mean difference of d(m) and d(r) obtained on in vivo MR imaging and histopathological examination was 0.7 mm (95% confidence interval, CI, -0.12 to 1.42 mm) and -1.1 mm (95% CI -2.29 to 0.14 mm), respectively. Almost all mesorectal nodes visible on MR imaging were found at the level of tumour or within 5 cm proximal to the tumour. This has implications for the planning of MR imaging and the level of mesorectal transection at surgery.

'One-stop' rectal bleeding clinics without routine flexible sigmoidoscopy are unsafe.

Over 90% of patients referred to surgeons for investigation of rectal bleeding have haemorrhoids, fissure-in-ano or proctitis. Full investigation of these patients to exclude colonic neoplasia or inflammatory bowel disease imposes a considerable load on a hospital's resources as well as exposing the patient to significant inconvenience and morbidity. A 'one-stop' outpatient clinic was established, with selective use of flexible sigmoidoscopy, based on the judgement and clinical findings of a single experienced surgeon. Over a 4 month period, 344 patients were assessed, and 326 were identified as not needing flexible sigmoidoscopy. At 3 and 6 monthly follow-up, 22 presented with persistent rectal bleeding and three previously unidentified cancers were found on performance of flexible sigmoidoscopy. If a 'one-stop' policy is to be used in the management of rectal bleeding, routine flexible sigmoidoscopy is essential for all patients.

Pancreatic islet purification using bovine serum albumin: the importance of density gradient temperature and osmolality.

Euro-Ficoll and bovine serum albumin (BSA) are two of the most commonly used density gradient media for the purification of pancreatic islets. Euro-Ficoll is based upon Euro-Collins, a cold storage medium, and must, therefore, be used at 4 degrees C. The ionic composition of BSA, however, is likely to contribute to hypothermic cellular swelling, and this may influence the efficiency of islet purification using this medium at 4 degrees C. Experience in this laboratory also suggested that batch-to-batch variation in islet purity using BSA was related to differences in BSA osmolality. The aim of this study was to assess the effect of gradient medium temperature and osmolality on the purification of human and porcine islets using BSA. Pancreata were collagenase-digested, and islets were purified on continuous linear density gradients of BSA. The distribution of insulin and amylase in each gradient was assayed, and used to calculate the median density of islets and exocrine tissue, and the efficiency of islet purification (% amylase contamination at a fixed insulin yield), using: 1) gradient osmolalities of 300, 400, and 500 mOsm/kg H2O (seven porcine pancreata), and 2) gradients at 4 degrees C and at 22 degrees C (eight human and seven porcine pancreata). Increase in density gradient osmolality produced increases in porcine exocrine tissue density which exceeded changes in islet density, resulting in improved islet purity, maximal at a BSA osmolality of 400 mOsm/kg H2O. For human pancreata there was no significant change in pancreatic tissue densities nor islet purity with temperature.(ABSTRACT TRUNCATED AT 400 WORDS)

Porcine islet isolation: prospective comparison of automated and manual methods of pancreatic collagenase digestion.

A prospective study was undertaken to compare an automated method of porcine pancreatic digestion with a simpler manual procedure. These techniques have not previously been compared directly. After intraductal distension with collagenase, seven porcine pancreata were divided longitudinally; half of each was digested by the automated method and half by the manual technique. Islet yield and purity were measured. Compared with the manual technique, the automated method isolated a significantly greater total volume of islet tissue (median (range) 3.56 (1.39-5.30) versus 1.07 (0.46-1.92) mm3/g, P = 0.022), increased the median (range) number of 105-microns islet equivalents isolated (5875 (2294-8746) versus 1766 (759-3168) per g, P = 0.022) and improved the islet cleavage index (median (range) 92 (89-99) versus 82 (78-92) per cent, P = 0.035). It is concluded that, although the automated method is more complicated to set up, it greatly improves the yield of intact islets from the porcine pancreas.

Laryngeal oedema from a neck haematoma. A complication of internal jugular vein cannulation.

Laryngeal oedema occurred after formation of a neck haematoma after attempted internal jugular vein cannulation. This resulted in complete respiratory obstruction and respiratory arrest and it was impossible to ventilate her lungs manually or intubate her trachea. Oxygenation of the patient was only possible using transtracheal ventilation.

Resistance to fluid flow through two spinal needles.

A new needle, 120 mm long and 26 gauge in diameter, has been introduced for subarachnoid anaesthesia. The resistance to flow through the needle was measured using a pressure monitor infusion pump and compared with the resistance to flow through a 90-mm 26-gauge needle; there was a threefold increase in resistance in the 120-mm needle compared to the 90-mm needle, which could not be explained by the difference in length alone and must reflect a decrease in the internal diameter of the long needle. This results in difficulty in identifying the subarachnoid space by backflow of cerebrospinal fluid.

A simple method for the release of islets by controlled collagenase digestion of the human pancreas.

A simple technique for the controlled collagenase digestion of the human pancreas is described. The pancreas is distended with collagenase, and a biopsy taken and divided into 5 pieces that are placed in Universals containing minimal essential medium and dithizone at 39 degrees C. The pancreas itself is incubated in MEM at 39 degrees C. Starting at 5 min and at intervals thereafter, a Universal is removed from the water bath, shaken for 30 sec, and the contents examined by microscopy. As soon as free cleaved islets are seen, the pancreas is placed into one compartment of a kidney-bowl divided in half by a 1-mm mesh. The pancreas is gently teased apart and fluid digest in the empty half of the bowl aspirated and passed through a 500-micron mesh into ice-cold MEM containing 20% newborn calf serum. This process is repeated until the digestion process has ceased. Using this technique on 20 consecutive pancreata, median wt. (range) 53.9 (45.2-72.9) g, we have counted 131,672 (43,516-400,000) islets in the digest, equivalent to 2394 (715-8000) islets/g pancreas. The volume of islet tissue in the digest was 299 (26-1341) mm3 equivalent to 5.81 (0.36-26.81) mm3/g pancreas. In conclusion, we have found this simple technique to be an effective method for the controlled collagenase digestion of the human pancreas.

Determination of aflatoxins in peanut products using reverse phase HPLC.

A high performance liquid chromatographic (HPLC) method is described for the determination of the four major aflatoxins, B1, B2, G1 and G2, in peanut products. The aflatoxins are extracted by adapting a procedure developed by Pons (1) at the SRRC, USDA, and quantitated utilizing a new 5 mum reverse-phase column with NaCl/acetontrile/methanol mobile phase (3 + 1 + 1). The 5 mum column achieved baseline resolution of each of the four aflatoxins. Retention times and peak heights were reproducible. The procedure was successfully applied to several types of peanut products and was applicable to both roasted and unroasted peanuts, which is a decided advantage over the current CB and BF extraction methods. Additionally, it can be used for sweetened peanut matrixes with no interferences in the chromatography. The total time required for sample preparation and aflatoxin determination is less than 1.5 hours.