Polymyxin B, scavenger of endotoxin, enhances isolation yield and in vivo function of islets.

Collagenase purified from bacteria has been used to isolate islets for transplantation. However, collagenase is contaminated with small amounts of endotoxin, which induces dysfunction or apoptosis of islets. In this study, we investigated the effects of polymyxin B, endotoxin scavenger, on the yield and quality of isolated islets. It is revealed that polymyxin B neutralized endotoxin in vitro and inhibited endotoxin-mediated decreases of the glucose stimulation index. Additionally, adenosine triphosphate (ATP) quantitation, islet regression assay, and caspase-3 activation assay demonstrated that polymyxin B efficiently blocked the toxic effects induced by endotoxin. Thereafter, we isolated mouse islets both with and without polymyxin B and compared total islet equivalents (IEQs), glucose-stimulated insulin release, and ATP content. Polymyxin B enhanced islet recovery, and ATP content of islets, and glucose stimulation index, and reduced TNF-alpha expression of islets. Marginal transplantation (200 IEQs/mouse) under the kidney capsule of diabetic mice induced normoglycemia in 30% of the polymyxin B group, but not in any mouse of control group. This result suggests that islets isolated with polymyxin B more effectively lower blood glucose levels as compared with control islets. Thus, polymyxin B could serve as a useful agent in the protection of islets from endotoxin-induced inflammation and apoptosis.

Concomitant pulmonary tuberculosis and leprosy.

Concomitant tuberculosis and leprosy is uncommon, even in endemic countries. We report a patient with borderline lepromatous leprosy and type 1 reversal reaction initially diagnosed while the patient was undergoing treatment for pulmonary tuberculosis. The diagnosis was on the basis of characteristic histopathology and Fite-Farraco stain.

Biopsy techniques. Diagnosis of melanoma.

The biopsy of a suspicious pigmented lesion is critical to establishing a correct and complete diagnosis. It allows the dermatopathologist accurately to diagnose melanoma and to gauge maximum depth of invasion (and other histologic criterion). This, in turn, influences the extent of further necessary surgery or other adjuvant therapy. Furthermore, choosing the appropriate biopsy technique provides adequate cosmetic results, bearing in mind that the excisional technique is ideal because it removes the suspicious lesion en toto. Excisional biopsies should extend to the subcutaneous fat by means of a punch biopsy, a fusiform ellipse, or a saucerization. Incisional biopsies can be performed in certain circumstances, but should be done so with caution because sampling error may lead to missed diagnosis or inaccurate histologic criterion, such as depth.

Cross-reactivity among epoxy acrylates and bisphenol F epoxy resins in patients with bisphenol A epoxy resin sensitivity.

OBJECTIVE: The study's objective was 2-fold: first, to evaluate the potential cross-reactivity between Bis-A epoxy resins and epoxy acrylates and second, to study the cross reactivity between Bis-A epoxy resins and newer Bis-F epoxy resins in patients with allergic contact dermatitis to epoxy resins and had positive patch test to the standard epoxy resin based on bisphenol A. METHODS: Forty-one patients were patch tested to 23 chemicals including epoxy acrylates, Bis-A epoxy resins, and Bis-F epoxy resins, as well as reactive diluents and nonbisphenol epoxy resins. Questions concerning exposure to epoxy resins, occupational history, and problems with dental work were completed. RESULTS: All patients included in the study had positive reactions to the standard Bis-A epoxy resin. Twenty percent (8 of 41) of the patients reacted to at least one of the epoxy acrylates; the most common reaction was to Bis-GMA. Five of 8 patients who reacted to the epoxy acrylates had dental work, but only one patient had problems from her dental work. Six of 8 patients (75%) who reacted to epoxy resins and epoxy acrylates did not react to aliphatic acrylates. Thirty-two percent (13 of 41) reacted to tosylamide epoxy resin, and none reacted to triglycidyl isocyanurate resin. In addition, all patients (100%) had positive reactions to at least one of the Bis-F epoxy resins that were tested. CONCLUSIONS: Most patients with sensitivity to Bis-A epoxy resins do not cross-react with epoxy acrylates. Patients with positive patch test reactions to epoxy acrylates used in dentistry usually do not have symptoms from their dental work. To our knowledge, this is the largest series of patients with sensitivity to the standard Bis-A epoxy resin that have been patch tested with the more recently introduced Bis-F epoxy resins. There is significant cross-reactivity between Bis-A and Bis-F epoxy resins, which can be explained by their structural similarity.