Platelet adhesion to collagen types I through VIII under conditions of stasis and flow is mediated by GPIa/IIa (alpha 2 beta 1-integrin)

Platelet adhesion to fibrillar collagens (types I, II, III, and V) and nonfibrillar collagens (types IV, VI, VII, and VIII) was investigated in the presence of physiologic concentrations of divalent cations under conditions of stasis and flow. Under static conditions, platelet adhesion was observed to collagen types I through VII but not to type VIII. Under flow conditions, platelet adhesion to collagen types I, II, III, and IV was almost independent of shear rates above 300/s. Collagen type V was nonadhesive. Platelet adhesion to collagen type VI was shear rate-dependent and optimal at a rate of 300/s. Collagen types VII and VIII showed minor reactivity and supported platelet adhesion only between shear rates 100 to 1,000/s. Monoclonal antibody (MoAb) 176D7, directed against platelet membrane glycoprotein Ia (GPIa; very late antigen [VLA]-alpha 2 subunit), completely inhibited platelet adhesion to all collagens tested, under conditions of both stasis and flow. Platelet adhesion to collagen type III at shear rate 1,600/s was only inhibited for 85%. The concentration of antibody required for complete inhibition of platelet adhesion was dependent on the shear rate and the reactivity of the collagen. An MoAb directed against GPIIa (VLA-beta subunit) partially inhibited platelet adhesion to collagen. These results show that GPIa-IIa is a major and universal platelet receptor for eight unique types of collagen.     

Controlled trial of Iodosorb in chronic venous ulcers

Cadexomer iodine (Iodosorb) is a hydrophilic starch powder containing iodine, which is a suitable dressing for granulating wounds such as venous ulcers. A total of 61 outpatients with chronic venous ulcers participated in a randomised optional crossover trial using cadexomer iodine or a standard dressing for their ulcers. The trial lasted for 24 weeks or until the ulcer had healed. Two patients withdrew during the course of the trial. Both treatments were highly effective, but the epithelium of ulcers dressed with cadexomer iodine grew again significantly faster (p less than 0.001). At the midpoint of the trial (12th week) 13 of 30 patients receiving standard treatment were changed to cadexomer iodine, while only three of 29 receiving cadexomer iodine changed to the standard dressing (p less than 0.02). In most cases ulcers were dressed and rebandaged daily by the patients themselves after instruction and supervision. This may be better than having dressings and bandages applied by professionals less regularly.     

Experience using the carbon dioxide laser in the removal of cutaneous tattoos

A preliminary study was undertaken to determine if the carbon dioxide laser was a suitable technique for the removal of tattoos. Twenty-eight patients with 47 tattoos had their tattoos removed by the carbon dioxide laser. The results were assessed by an independent observer 1 year after completion of treatment. The most satisfactory results were obtained in patients with discrete linear tattoos of amateur origin. In those with polychromatic blocked-in tattoos of professional origin, hypertrophic scars occurred and the overall result was unsatisfactory.     

The immotile cilia syndrome: radiological manifestations

The immotile cilia syndrome (ICS) is an uncommon disorder characterized by specific and genetically determined defects of cilia that cause upper and lower respiratory disease. We reviewed the radiographic patterns in 30 patients who had ICS (15 females, 15 males) and ranged in age from newborn to 26 years. Except for two neonates, sinusitis and otitis were present in all patients. Chest radiographic abnormalities, universally present, included bronchial wall thickening, hyper-inflation, segmental atelectasis or consolidation, and segmental bronchiectasis. Situs inversus, present in 50% (7 females, 8 males), was not an essential part of this disorder. Radiologically, the disease progresses from bronchial wall thickening with or without hyperinflation, to increasing hyperinflation plus parenchymal changes including segmental atelectasis, consolidation, and bronchiectasis. There is also a predilection for anatomic middle lobe abnormalities. The radiological appearance and clinical state have similarities to cystic fibrosis, although they are less severe and less progressive. ICS should be considered in the differential diagnosis of slowly progressive chronic lung disease, sinusitis, and otitis.     

Augmented locomotor recovery after spinal cord injury in the athymic nude rat

The immune response contributes to ongoing secondary tissue destruction following spinal cord injury (SCI). Although infiltrating neutrophils and monocytes have been well studied in this process, T-cells have received less attention. The objective of this study was to assess locomotor recovery and tissue morphology after SCI in athymic (nude) rats, in which T-cell numbers are reduced. Results in athymic rats were compared with heterozygote littermates with normal T-cell profiles and with Sprague-Dawley rats from previous studies in our lab. Following transection of rat spinal cords at T10, we assessed the animals' locomotor recovery on a weekly basis for up to 11 weeks, using the Basso-Beattie-Bresnahan locomotor rating scale. Nude rats showed better locomotor recovery than did heterozygote or Sprague-Dawley rats, achieving scores of 5.6 +/- 0.8 versus 1.0 +/- 0.0, respectively (p = 0.002), at 4 weeks postinjury. The improved recovery of nude rats persisted for the 11-week postinjury assessment period, and was consistent with improved spinal reflexes rather than with recovery of descending motor pathways. Anatomical evaluation at 11 weeks indicated no difference in nude versus heterozygote rats in the size or distribution of cavities caudal to the transection site, but secondary damage was more severe rostral to the transection site in heterozygote rats. In neither group did cavities extend beyond 4 mm caudal to the transection site, and were therefore not directly responsible for the functional differences between the two groups. Cellular expression of the microglia/macrophage antigen ectodysplasin A (ED1) was reduced in nude rats as compared to heterozygotes, but no difference was observed in expression levels of 5-hydroxytryptamine, the 200-kDa neurofilament, or glial fibrillary acidic protein. The findings of the study show that a reduction in T-cell numbers significantly improves locomotor recovery after spinal cord transection, indicating a deleterious role for these immune cells in neural repair after trauma.     

The efficacy of intra-articular bupivacaine for relief of pain following arthroscopy of the ankle

The intra-articular injection of local anaesthetic is frequently used for pain relief after arthroscopy. There is, however, no published evidence of the analgesic effect of bupivacaine in the ankle. In a randomised, double-blind study, 35 patients undergoing arthroscopy of the ankle were allocated to receive intra-articular saline or bupivacaine. Pain was assessed using pain scores and additional analgesic requirements. Intra-articular bupivacaine had a significant analgesic effect in the immediate post-operative period, reducing pain scores and the need for additional analgesics. We recommend the use of intra-articular bupivacaine for post-operative analgesia in ankle surgery.