Islet isolation assessment in man and large animals

Recent progress in islet isolation from the pancreas of large mammals including man, accentuated the need for the development of precise and reproducible techniques to assess islet yield. In this report both quantitative and qualitative criteria for islet isolation assessment were discussed, the main topics being the determination of number, volume, purity, morphologic integrity and in vitro and in vivo function tests of the final islet preparations. It has been recommended that dithizone should be used as a specific stain for immediate detection of islet tissue making it possible to estimate both the total number of islets (dividing them into classes of 50 μ diameter range increments) and the purity of the final preparation. Appropriate morphological assessment should include confirmation of islet identification, assessment of the morphological integrity and of the purity of the islet preparation. The use of fluorometric inclusion and exclusion dyes together have been suggested as a viability assay to simultaneously quantitate the proportion of cells that are intact or damaged. Perifusion of islets with glucose provides a dynamic profile of glucose-mediated insulin release and of the ability of the cells to down regulate insulin secretion after the glycemic challenge is interrupted. Although perifusion data provides a useful guide to islet viability the quantity and kinetics of insulin release do not necessarily predict islet performance after implantation. Therefore, the ultimate test of islet viability is their function after transplantation into a diabetic recipient. For this reason, in vivo models of transplantation of an aliquot of the final islet preparation into diabetic nude (athymic) rodents have been suggested. We hope that these general guidelines will be of assistance to standardize the assessment of islet isolations, making it possible to better interpret and compare procedures from different centers. © 1990 Casa Editrice il Ponte

Percutaneous transluminal angioplasty for critical limb ischaemia in octogenarians and nonagenarians

AbstractObjective. To determine the early and late outcome of percutaneous transluminal angioplasty (PTA) for critical limb ischaemia (CLI) in patients aged 80 years and over.Methods. Retrospective case note review of all patients aged 80 years and over who underwent attempted PTA for CLI between 1st January 1999 and 31st December 2000. Minimum follow-up was 12 months with a maximum of 42 months.Results. One hundred and twenty-eight PTAs were attempted in 113 severely ischaemic limbs of 98 patients (36 men and 62 women of median age 84, range 80–97, years). Seventy patients had significant co-morbidity. The indication for revascularisation was rest pain in 47 procedures, ulceration in 66 and digital gangrene in 15. The anatomical segments involved were iliac (n=19), superficial femoral (n=92), popliteal (n=91) and infrapopliteal (n=72). The technical success rate was 108 of 128 (84%) procedures. Early technical complications occurred in 24 (19%) procedures: four major, 20 minor. The 30-day operative mortality rate was six of 128 (5%). The median (range) in-hospital stay was two (1–72) days. Early or delayed surgical revascularisation was required in 11 limbs and there were six major limb amputations during the study period. The 24-month patient survival rate was 59%. The 24-month primary and secondary symptomatic patency and secondary limb salvage rates were 52, 69 and 95%, respectively.Discussion. PTA is safe, requires a short hospital stay, and is clinically effective in the majority of very elderly patients with CLI. Although minimally invasive, the relatively high peri-procedural mortality rate and low 24-month survival rate reflect the high co-morbidity of this group of patients

The role of superficial venous surgery in patients with combined superficial and segmental deep venous reflux

AbstractObjectives: superficial venous surgery heals chronic venous ulceration (CVU) in the majority of patients with isolated superficial venous reflux (SVR). This study examines the role of superficial venous surgery in patients with comined SVR and segmental deep venous reflux (DVR). Methods: combined SVR and segmental DVR was diagnosed by venous duplex in 53 limbs in 49 patients (24 men and 25 women of median age 66, range 27-90, years). Fourteen limbs had varicose veins (CEAP class 2-4) and 39 (74%) had active CVU (CEAP class 6). Duplex ultrasound was performed before and three months after local anaesthetic superficial venous surgery. Perforator vein surgery, skin grafting and compression bandaging or hosiery were not used. Results: forty-two limbs with long saphenous vein (LSV) reflux underwent sapheno-femoral disconnection, 10 with short saphenous vein (SSV) reflux underwent sapheno-popliteal disconnection and one limb with LSV and SSV reflux had sapheno-femoral and sapheno-popliteal disconnection. Segmental DVR was confined to the superficial femoral vein (SFV) in 16 limbs, below knee popliteal vein (BKPV) in 25 and gastrocnemius vein (GV) in 12 limbs. Overall, duplex demonstrated post-operative resolution of segmental DVR in 26 of 53 (49%) limbs. Resolution of segmental SFV reflux occurred in 12 of 16 (75%) limbs compared with 14 of 37 (38%) limbs with segmental BKPV or GV reflux (p = 0.018). Segmental DVR resolved in 19 of 39 (49%) limbs with CVU and ulcer healing occurred in 30 of 39 (77%) limbs at 12 months with a median time to healing of 61 (range 14-352) days. Segmental DVR resolved in 14 of 30 (47%) limbs with a healed ulcer: 7 of 9 (78%) limbs with SFV and 7 of 21 (33%) with BKPV or GV reflux (p = 0.046). Conclusions: these data demonstrate that in patients with combined SVR and segmental DVR, superficial venous surgery alone corrects DVR in almost 50% of limbs and is associated with ulcer healing in 77% of limbs at 12 months. These findings suggest an extended role for superficial venous surgery in the management of patients with complicated venous disease.Eur J Vasc Endovasc Surg 25, 469-472 (2003

Seizures after carotid endarterectomy: Hyperperfusion, dysautoregulation or hypertensive encephalopathy?

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