An in vitro human skin test for assessing sensitization potential.

Sensitization to chemicals resulting in an allergy is an important health issue. The current gold-standard method for identification and characterization of skin-sensitizing chemicals was the mouse local lymph node assay (LLNA). However, for a number of reasons there has been an increasing imperative to develop alternative approaches to hazard identification that do not require the use of animals. Here we describe a human in-vitro skin explant test for identification of sensitization hazards and the assessment of relative skin sensitizing potency. This method measures histological damage in human skin as a readout of the immune response induced by the test material. Using this approach we have measured responses to 44 chemicals including skin sensitizers, pre/pro-haptens, respiratory sensitizers, non-sensitizing chemicals (including skin-irritants) and previously misclassified compounds. Based on comparisons with the LLNA, the skin explant test gave 95% specificity, 95% sensitivity, 95% concordance with a correlation coefficient of 0.9. The same specificity and sensitivity were achieved for comparison of results with published human sensitization data with a correlation coefficient of 0.91. The test also successfully identified nickel sulphate as a human skin sensitizer, which was misclassified as negative in the LLNA. In addition, sensitizers and non-sensitizers identified as positive or negative by the skin explant test have induced high/low T cell proliferation and IFNγ production, respectively. Collectively, the data suggests the human in-vitro skin explant test could provide the basis for a novel approach for characterization of the sensitizing activity as a first step in the risk assessment process.

Evaluation of the pressure leak test in increasing the lifespan of flexible ureteroscopes.

INTRODUCTION: Flexible ureteroscopes are expensive and delicate instruments that are integral in the offering of a minimally invasive technique of diagnosis and treatment of urolithiasis. Published literature has identified the importance of early damage recognition in preventing frequent use of the scope that would lead to further damage and high repair and replacement costs. Our study was designed to examine the outcome of the pressure leak test on the condition of flexible ureteroscopes after every use and analysing the damage and costs of maintenance. PATIENTS AND METHODS: A prospective study was designed with two treatment groups. Group 1, 95 consecutive procedures (n = 95) of flexible ureterorenoscopy and laser fragmentation of renal calculi were performed with ACMI DUR 8, (a scope with no in-built leak test facility). This was compared against group 2, where 98 procedures of laser fragmentation of renal calculi (n = 98) were performed using Storz Flex X(2) Ureteroscopes (with a in-built leak test facility). All scopes in Group 2 were tested for pressure leak after every procedure and the outcome of the tests recorded. RESULTS: Both groups were comparable for grade of surgeon; stone location, size & number; access sheath usage and duration of lasering. In Group 1, there were seven scope damages resulting in repairs/replacement amounting to costs $46264.40 (7.1% damage). In Group 2, three scopes revealed a positive pressure leak test, implying damage with repair costs of $9952.80 (3.1% damage) (p < 0.05). Significant cost savings and reduction in downtime were made in Group 2. CONCLUSIONS: Pressure leak testing following flexible ureterorenoscopy helped to significantly control costs of maintenance and repair. Newer scopes should have a leak testing mechanism as it prevents further detrimental damage to the scope, build-up of repair costs are avoided and there is an increase in the longevity of these delicate instruments.

[Bone tissue engineering. Reconstruction of critical sized segmental bone defects in the ovine tibia]. / Knochen-Tissue-Engineering. Rekonstruktion segmentaler Knochendefekte kritischer Größe in der Schafstibia.

Well-established therapies for bone defects are restricted to bone grafts which face significant disadvantages (limited availability, donor site morbidity, insufficient integration). Therefore, the objective was to develop an alternative approach investigating the regenerative potential of medical grade polycaprolactone-tricalcium phosphate (mPCL-TCP) and silk-hydroxyapatite (silk-HA) scaffolds.Critical sized ovine tibial defects were created and stabilized. Defects were left untreated, reconstructed with autologous bone grafts (ABG) and mPCL-TCP or silk-HA scaffolds. Animals were observed for 12 weeks. X-ray analysis, torsion testing and quantitative computed tomography (CT) analyses were performed. Radiological analysis confirmed the critical nature of the defects. Full defect bridging occurred in the autograft and partial bridging in the mPCL-TCP group. Only little bone formation was observed with silk-HA scaffolds. Biomechanical testing revealed a higher torsional moment/stiffness (p < 0.05) and CT analysis a significantly higher amount of bone formation for the ABG group when compared to the silk-HA group. No significant difference was determined between the ABG and mPCL-TCP groups. The results of this study suggest that mPCL-TCP scaffolds combined can serve as an alternative to autologous bone grafting in long bone defect regeneration. The combination of mPCL-TCP with osteogenic cells or growth factors represents an attractive means to further enhance bone formation.

Osteosarcoma is characterised by reduced expression of markers of osteoclastogenesis and antigen presentation compared with normal bone.

BACKGROUND: Osteosarcoma (OS) is the most common primary bone tumour in children and adolescents. Patients who respond poorly to chemotherapy have a higher risk of metastatic disease and 5-year survival rates of only 10-20%. Therefore, identifying molecular targets that are specific for OS, or more specifically, metastatic OS, will be critical to the development of new treatment strategies to improve patient outcomes. METHODS: We performed a transcriptomic analysis of chemo-naive OS biopsies and non-malignant bone biopsies to identify differentially expressed genes specific to OS, which could provide insight into OS biology and chemoresistance. RESULTS: Statistical analysis of the OS transcriptomes found differential expression of several metallothionein family members, as well as deregulation of genes involved in antigen presentation. Tumours also exhibited significantly increased expression of ID1 and profound down-regulation of S100A8, highlighting their potential as therapeutic targets for OS. Finally, we found a significant correlation between OS and impaired osteoclastogenesis and antigen-presenting activity. The reduced osteoclastogenesis and antigen-presenting activity were more profound in the chemoresistant OS samples. CONCLUSION: Our results indicate that OS displays gene signatures consistent with decreased antigen-presenting activity, enhanced chemoresistance, and impaired osteoclastogenesis. Moreover, these alterations are more pronounced in chemoresistant OS tumour samples.

Effect of hospital and surgeon volume on patient outcomes following treatment of abdominal aortic aneurysms: a systematic review.

OBJECTIVES: This systematic review assessed the efficacy of centralisation for the treatment of unruptured and ruptured abdominal aortic aneurysms. Patient outcomes achieved by low and high volume hospitals/surgeons, including morbidity, mortality and length of hospital stay, were used as proxy measures of efficacy. DESIGN: Systematic review was designed to identify, assess and report on peer-reviewed articles reporting outcomes from unruptured and ruptured abdominal aortic aneurysms. No language restriction was placed on the databases searched. MATERIALS: Only peer-reviewed journals articles were included. METHODS: To ensure the contemporary nature of this review, only studies published between January 1997 and June 2007 were sought. Studies were included if they reported on at least one volume type and patient outcome. RESULTS: Twenty two studies were included in this review. In the majority of group assessments, the number of studies reporting statistical significance was similar to the number of studies reporting no statistical significance. CONCLUSION: The paucity of studies reporting statistically significant results demonstrates that although this evidence exists, its potential to be overstated must also be taken into account when drawing conclusions as to its efficacy for twenty first century healthcare systems.

Laparoscopic management of iatrogenic bladder injury and bladder stone formation following laparoscopic inguinal herniorrhaphy.

BACKGROUND: Herniorrhaphy is one of the most commonly performed operations in the UK. Approximately 1 per 1,000 of the population has a groin hernia. METHOD AND RESULT: We report on a rare complication following laparoscopic inguinal herniorrhaphy of bladder stone formation and its management. CONCLUSION: To our knowledge a combined laparoscopic repair of the urinary bladder wall, following iatrogenic injury by a mesh fixation clip and retrieval of bladder stone (induced through the misplacement of the clip) has not been described previously.

Single dose mezlocillin versus three dose cefuroxime plus metronidazole for the prophylaxis of wound infection after large bowel surgery.

A prospective, randomized, controlled trial was conducted in 116 consecutive patients undergoing colorectal surgery to compare single dose prophylaxis with mezlocillin to cefuroxime plus metronidazole in three doses. Patients were randomized to receive either a single dose of iv mezlocillin (5.0 g) or three doses of iv cefuroxime plus metronidazole at 8-hourly intervals. The first dose was given on the operating table. The overall wound infection rate in the mezlocillin treated patients (n = 54) was 30% and in the patients treated with cefuroxime plus metronidazole (n = 56) 25%. This difference is not statistically significant. When trivial wound infections were disregarded the wound infection rates were 11% and 16% respectively, which again was not statistically significant.

Giant cell tumor of bone.

Giant cell tumor of bone is an unusual neoplasm and treatment commonly leads to local recurrence. This can be related to the aggressiveness of the tumor or to the incompleteness of its removal. This study includes 27 cases that presented to our institution between the 1984 and 1994. One case was as a consultation only and 9 cases, either Campanacci Grade 3 or patients with considerable joint destruction, were treated by resection and reconstruction. One case was treated by curettage and cementation. Sixteen cases were treated with a combination of radical curettage, high speed burring, pulsatile lavage, and bone graft (either autograft or allograft mixed with autograft). No other adjuvant therapy was used. All of these 16 cases had a minimum follow-up of 5 years and none had a local recurrence. This study demonstrates that local control of giant cell tumors can be obtained by appropriate staging, resection of aggressive tumors, and by conservative management of the others. Such conservative management provides a bony matrix for the subchondral bone that is preferable to other treatments that have become popular in recent years, including cementation. This should provide better joint function in the longer term. High local recurrence rates have been reported in other series, but by a combination of appropriate selection of cases and by careful treatment of the Campanacci Grade 1 and 2 cases, these patients can have an uncomplicated outcome.

Limb salvage for soft-tissue sarcomas of the foot and ankle.

We evaluated the oncological and functional outcome of 27 patients who had limb salvage for a soft-tissue sarcoma of the foot or ankle between 1992 and 2007, with a mean follow-up of 7.5 years (1.05 to 16.2). There were 12 men and 15 women, with a mean age at presentation of 47 years (12 to 84). Referrals came from other hospitals for 16 patients who had previous biopsy or unplanned excision, and 11 presented de novo. There were 18 tumours located in the foot and nine around the ankle. Synovial sarcoma was the most frequent histological diagnosis. Excision was performed in all cases, with 16 patients requiring plastic surgical reconstruction with 13 free and three local flaps. Adjuvant treatment was undertaken in 20 patients, 18 with radiotherapy and two by chemotherapy. Limb salvage was successful in 26 of the 27 patients. There have been two local recurrences and two mesenchymal metastases. Four patients have died of their sarcoma and two of other causes. Function was evaluated with the Toronto Extremity Salvage Score and a mean overall score of 89.40 (52.1 to 100) was obtained. A questionnaire revealed that all surviving patients are able to wear normal shoes and none require a walking aid. Limb salvage can achieve good oncological and functional results with additional treatment.

Vascularised free fibular flap in bone resection and reconstruction.

This paper compares allograft alone and in combination with vascularised free fibular flaps (FFF) to reconstruct long bone defects after tumour excision. We present 33 cases, 21 of these patients had reconstruction with an allograft alone as the initial procedure. Nine patients underwent reconstruction with FFF plus allograft plus iliac crest bone graft (ICG), two patients underwent reconstruction with a FFF and ICG and one patient underwent reconstruction with an allograft, a pedicled fibular flap and a FFF. The allograft was obtained from the Queensland Bone Bank and had been irradiated to 25 000Gy. In our experience (N=21) the complication rates with allograft alone were: delayed union 3, nonunion 7, fractured allograft 6, infection requiring resection of the allograft 3, other infections 2. The revision rate was 48% (10 cases of which five required a free fibular flap) and an average of 1.8 revision procedures were required. In the lower limb cases, the mean time to full weightbearing was 20 months and 40% were full weightbearing at 18 months. We felt that the high complication rate compared with other series may have been related to the irradiation of the graft. FFFs were used in 18 cases, 12 cases were primary reconstructions and six were revision reconstructions. The mean fibular length was 19.4 cm (range 10-29 cm). There were no flap losses and the FFF united at both ends of 11 of 12 primary reconstruction cases. One case had nonunion at one end, giving a union rate of 96% (23 of 24 junctions). When a FFF was used in combination with an allograft as a primary reconstruction, the allograft nonunion rate was 50% (five of 10 cases). The mean time to full weightbearing in the lower limb cases was 7.5 months and 100% were full weightbearing at 18 months. The FFF hastens time to full weightbearing but does not appear to affect the complication rates of allograft. The number of revision procedures required is reduced in the presence of a FFF and is the latter is a useful technique for the salvage of refractory cases.

Surgery for impotence.

Many men presenting with impotence can be cured by surgical intervention. Psychosexual counselling is always beneficial but surgery may be indicated when there is irreversible organic erectile impotence or when there is an anatomical abnormality of the penis preventing coitus. The diagnosis and management of such disorders are summarized.

Pharmacocavernometry: a modified papaverine test.

The papaverine test has become established in the investigation of impotence. Although a full response to papaverine excludes a significant vascular lesion, failure to respond may be due to either arterial deficiency or venous leakage. Pharmacocavernometry, which combines the papaverine test and an artificial erection test, was performed in 126 patients. Intracorporeal pressure was monitored following the intracorporeal injection of 80 mg papaverine; 10 min later, saline was infused to determine the presence of a venous leak. Five different responses were observed. Patients with a Type 1 or 2 response were psychogenic or neurogenic. Patients with a Type 3 response were arteriogenic and patients with a Type 4 or 5 response had significant venous leakage. The modified papaverine test permits more information to be gained concerning the aetiology of the impotence.

A nonbacterial cause of post-traumatic soft-tissue gas.

A young male sustained a wound on the lateral aspect of the right thigh, presenting 24 hours later with subcutaneous crepitus over the thigh. He was systemically well, Gram stains and wound culture were negative. The cause was a sucking wound due to the valvelike action of the iliotibial band.

Intra-operative implant brachytherapy in the management of soft-tissue sarcomas.

BACKGROUND: The management of localized soft-tissue sarcomas remains complex. This is a retrospective review of a single institution experience with manual afterloaded brachytherapy following intra-operative implantation of the tumour bed during surgery. METHODS: Twelve patients over a 3-year period had resection for localized soft-tissue sarcomas and desmoids with insertion of intra-operative brachytherapy implants combined with resection for localized soft-tissue sarcomas. Manual afterloading of the implant with iridium wires was performed postoperatively in all patients. The low dose rate brachytherapy dose varied from 13 to 20 Gy. Supplementary external beam radiation was administered pre-operatively or postoperatively to bring the total dose of adjuvant irradiation to 60-65 Gy. RESULTS: After a median follow-up period of 29 months, the 3-year local disease-free survival rate was 63%. The 3-year actuarial survival rate was 83%. There were no failures within the high-dose region of the implant, although two patients had locoregional failures adjacent to the tumour bed at the edge of the radiation field. Three patients developed distant metastases. Side effects were noted in five patients. Wound breakdown and delayed wound healing occurred in two patients. One patient required an amputation as a result of chronic non-healing and wound pain. Pathological fractures occurred in two patients. Those patients who did not develop wound breakdown had good cosmetic and functional outcomes. CONCLUSION: Intra-operative implantation of the tumour bed in combination with tumour resection for soft-tissue sarcomas results in a high degree of local control with acceptable complications. This modality offers the patient a high chance of avoiding a more radical surgical procedure such as limb amputation.

The human penis: an unusual penetration of NPY-immunoreactive nerves within the medial muscle coat of the deep dorsal vein.

The deep dorsal penile vein was obtained from seven patients undergoing surgery for erectile dysfunction. The veins were studied histologically and immunohistochemically for serotonin, dopamine beta-hydroxylase, vasoactive intestinal polypeptide, neuropeptide Y, substance P, calcitonin gene-related peptide, somatostatin, and [Leu]- and [Met]enkephalin. Histologically, the deep dorsal vein was found to be a large muscular vein with a thin endothelial lining. The tunica media was composed of an inner longitudinally and an outer circularly arranged smooth muscle layer. Numerous vasa vasorum (up to 30 in a single transverse section) were found in the tunica adventitia. The greatest density of nerves supplying the deep dorsal vein and vasa vasorum were neuropeptide Y-immunoreactive nerves followed (in a decreasing order) by vasoactive intestinal polypeptide- and dopamine beta-hydroxylase-immunoreactive nerves. Substance P-, calcitonin gene-related peptide- and somatostatin-immunoreactive nerves, but not serotonin-, [Leu]- and [Met]enkephalin-immunoreactive nerves, were occasionally found around the deep dorsal vein. All these nerve fibers were confined to the adventitial-medial border except neuropeptide Y-immunoreactive nerves which in addition penetrated the tunica media to the subendothelial layer of the deep dorsal vein. In contrast, neuropeptide Y-immunoreactive nerves supplying the vasa vasorum were always confined to the adventitial-medial border. The possible function of the medial innervation of the deep dorsal vein by neuropeptide Y-immunoreactive nerves is discussed.

Malignant sacrococcygeal germ cell tumour in an adult.

In adults, malignant sacrococcygeal germ cell tumour is a rare cause for a presacral tumour, with only 17 cases having been reported in the literature since 1907. We report the case of a 34 year old male who presented with a 6 month history of symptoms relating to a malignant presacral tumour which required en bloc excision including the lower sacrum and rectum. He died with lung and mediastinal metastasis 7 months following surgical excision and adjuvant chemotherapy using Cisplatin, Bleomycin and Etoposide. Prior to his death, he had a severe polyarthritis of his peripheral joints and evidence of hypertrophic osteo-arthropathy. The literature indicates that adults with these tumours have a poor prognosis, with only one reported long-term survivor. Surgical excision offers the only chance of cure, with the role of adjuvant therapy not having been defined because of the small numbers.

The complications of extracorporeal shockwave lithotripsy: management and prevention.

Extracorporeal shockwave lithotripsy has been shown to be a safe and effective method of treating most upper urinary tract stones. Major complications, although few, include haemorrhage, septicaemia, "Steinstrasse" formation and cardiac arrhythmias. The experience from 600 consecutive cases is reviewed and methods of prevention are discussed.

Combination of percutaneous surgery and extracorporeal shockwave lithotripsy for the treatment of large renal calculi.

Open surgery for large or complex renal calculi may be difficult, particularly in patients with recurrent stones, and may require special operative techniques to preserve renal function. With the advent of percutaneous nephrolithotripsy (PCNL) and extracorporeal shockwave lithotripsy (ESWL) new approaches are now available for the treatment of these difficult cases. A review of 67 patients who presented between November 1984 and May 1986 has shown that it was possible to clear large stones in 71% of patients using a combination of PCNL and ESWL. There was no mortality; the morbidity for both procedures was low and was less than when either procedure was used alone for the treatment of complex stones.

Validity of PSA, free/total PSA ratio and complexed/total PSA ratio measurements in men with acute urinary retention.

The reliability of serum prostate specific antigen (PSA) measurements in men with acute urinary retention is unclear. Total PSA, free and complexed PSA were measured, and the free/total (f/t) PSA and complexed/total (c/t) PSA ratios calculated, prior to catheterisation and at 48 and 72 h post-catheterisation in 39 men with acute retention. Subsequent histology showed 12 patients had prostate cancer and 27 benign prostatic hypertrophy. Serum free and total PSA fell following catheterisation, while complexed PSA rose during the first 48 h then subsequently fell. The f/t PSA and c/t PSA ratios provided the best discrimination at 48-72 h with 100% sensitivity and 75-82% specificity.Prostate Cancer and Prostatic Diseases (2001) 4, 167-172.