Calcineurin Inhibitor Withdrawal from Sirolimus-Based Therapy in Kidney Transplantation: A Systematic Review of Randomized Trials

Calcineurin inhibitor (CNI) withdrawal has been used as a strategy to improve renal allograft function, however, it also carries risk of acute rejection. We conducted a systematic review of randomized trials that involved CNI withdrawal from a sirolimus-based immunosuppressive regimen. The search strategy yielded six trials (n = 1047 patients) reported in eight publications. CNI withdrawal from sirolimus-based therapy, was associated with an increased risk of acute rejection (risk difference, 6%; 95% CI 2-10%, p = 0.002) but a higher creatinine clearance (mean difference, 7.49 mL/min; 95% CI 5.08-9.89 mL/min, p < 0.00001) at 1 year compared to continued CNI and sirolimus therapy. Graft loss (relative risk, 0.87; 95% CI 0.46-1.64, p = 0.66) and death (relative risk, 0.88; CI 0.40-1.96, p = 0.76) were similar in both groups at 1 year. Hypertension was significantly reduced in the CNI withdrawal group (relative risk, 0.56; 95% CI 0.40-0.78, p = 0.0006). CNI withdrawal from sirolimus-based therapy is associated with an increased risk of acute rejection in the short term with a significant improvement in renal function and a reduction in hypertension. Longer follow-up is needed to determine if these changes will result in a significant improvement in patient and graft survival.     

The Hyperplantarflexion Ankle Fracture Variant

Various patterns of ankle fractures that are not accounted for by common classification systems have been the subject of case reports. The first difficulty with these variant patterns is recognizing all associated pathology, followed by the successful application of stable fixation. The purpose of this study was to describe the common morphologic features and ligamentous injuries of a unique variant fracture pattern, as well as the surgical treatment technique and the short-term functional and radiographic outcomes. Of 121 consecutive unstable ankle fractures over a 2-year period, 7 patients were found to have a similar constellation of injuries around the ankle. A vertical shear fracture of the posteromedial tibial rim was the main feature. Six of the 7 also had a fracture of the posterior malleolus. On magnetic resonance imaging, the deltoid and posterior tibiofibular ligaments were intact in all cases. Fractures were treated with open anatomic reduction of the posteromedial and posterior fragments with antiglide plate fixation. All fractures healed at 2 months without loss of reduction, fixation failure, or surgical complications. The average American Academy of Orthopaedic Surgeons lower extremity score was 79 at an average of 8 months' follow-up. The common radiographic and morphologic features associated with this posteromedial fracture indicate that it likely occurs through a common mechanism that involves hyperplantarflexion. The characteristics of this fracture pattern have not been fully described previously, but this ankle fracture variant may occur in up to 6% of cases. Unstable ankle fractures should be evaluated carefully for evidence of posteromedial involvement so appropriate treatment may proceed.     

Paediatric sedation in Australasian emergency departments

Sedation of children undergoing painful procedures in the emergency department provides a challenge to emergency department medical staff. Factors requiring consideratioii include the procedure to be performed, the pharmacology of the agents chosen and the support framework provided within individual hospitals for the after-care of sedated children. This paper presents the findings of a questionnaire sent to emergency departments accredited for advanced paediatric emergency registrar training in Australia and New Zealand in July 1996, to assess current sedation practices.     

Surgical margins after needle-localization breast biopsy

: The use of needle-localization breast biopsy (NLBB) for the early diagnosis of breast cancer is common. The therapeutic adequacy of tumor-free margins following NLBB is unknown. We hypothesized that the presence of residual tumor after reexcision (mastectomy, tylectomy, or quadrantectomy) does not depend on the margin status following NLBB. : Retrospective cohort analysis was performed on 890 consecutive NLBBs executed between January 1990 and June 1994. Patients with invasive breast neoplasia were divided into two groups based on the tumor margins after NLBB. Group 1 were the women with positive margins, and group 2 had negative margins. Breast specimens after reexcision were reviewed for evidence of residual invasive carcinoma. : Invasive neoplasia was present in 107 patients (12%). Surgical margins and definitive records of care were avaliable for 96 of them (90%). All 45 patients in group 1 and 38 (75%) of 51 patients in group 2 underwent reexcision of the initial biopsy site (P = 0.36). Residual invasive carcinoma was present in 10 patients (22%) in group 1 and 3 (8%) in group 2 (P = 0.13). : Invasive breast neoplasia diagnosed by NLBB requires reexcision regardless of tumor margins to achieve complete local surgical eradication of tumor.     

Immunotoxicology: an overview

It is now known that chemicals and drugs may induce selective toxicity which may alter the interactions between immunocompetent cells, especially if the toxicity occurs during proliferation and differentiation. Hence, a flexible panel of sensitive in vivo and in vitro assays has been developed and validated to assess the immunotoxicity or immunopharmacology of suspect agents in rodents. The combined use of such sequential analysis methods with host resistance assays can effectively define immunomodulation following exposure to xenobiotics. Methods development, refinement and validation will be an ongoing requirement because of our rapidly expanding knowledge of the cell biology of the immune system. Classic studies of the comparative preclinical toxicology of several immunosuppressive drugs have substantiated species similarities and have contributed significantly to the development of predictive rodent models for extrapolation to humans. Studies of immunopharmacology and immunotoxicity of cyclosporin A, for example, produced both the desired pharmacology and the undesired toxicity at similar doses in both rodents and humans. When species differences are observed during toxicology studies they are most probably due to differences in absorption, disposition, metabolism, excretion, or delivered dose at the target tissue, rather than major species differences in cellular targets or cell physiology. This assumption is the basis for using rodent species to predict the toxicity of chemicals and drugs under development.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anti-inflammatory effect of β2-agonists: Inhibition of TNF-α release from human mast cells

β₂-Agonists inhibit the release of preformed mediators such as histamine and newly synthesized mediators such as prostaglandin D₂ from mast cells. However, although mast cells have been identified as an important source of several cytokines including tumor necrosis factor-α (TNF-α), there is no information about their regulation by β₂-agonists. Thus given the importance of TNF-α in inflammation and the widespread use of β₂-agonists, we investigated the effect of long-acting (salmeterol) and short-acting (salbutamol) β₂-agonists on the secretion of TNF-α from human skin mast cells. Treatment of mast cells with salmeterol or salbutamol (100 nmol/L) inhibited the IgE-dependent release of TNF-α (82% and 74%, respectively). Moreover, 2-hour treatment with salmeterol, isoproterenol, or salbutamol inhibited mast cell cytotoxicity against a TNF-α–sensitive cell line, WEHI-164, with an IC₅₀ of 71, 50, and 29 nmol/L, respectively. Specificity for β-adrenergic receptors was shown with propranolol. The inhibitory effect of β₂-agonists was observed after only 20 minutes of treatment but was lost by 24 hours after removal of salbutamol and isoproterenol (7% and 11% inhibition remaining, respectively). In contrast, the inhibition of TNF-α release was increased 1 hour after removal of salmeterol and remained significant 24 hours later. Furthermore, β₂-agonists did not show tachyphylaxis for the inhibition of TNF-α release. Thus selective β₂-agonists demonstrate anti-inflammatory activity by inhibiting the release of TNF-α from mast cells stimulated through their IgE receptor or by a tumor target cell. This inhibitory effect of β-agonists may be important in their mode of action in the treatment of allergic diseases. (J Allergy Clin Immunol 1997;100:825-31.)     

Pilomatrix carcinoma. A new case

We present a new case of Pilomatrix Carcinoma after having review the 22 cases previously published. The tumor arisen in a 74 years old male, in the left preauricular region. The lesion was excised with wide margins. A year after there is not any evidence of recurrence or metastases.     

Postoperative Apnea in Former Preterm Infants after Inguinal Herniorrhaphy: A Combined Analysis

Background: Controversy exists as to the risk for postoperative apnea in former preterm infants. The conclusions of published studies are limited by the small number of patients.

Methods: The original data from eight prospective studies were subject to a combined analysis. Only patients having inguinal herniorrhaphy under general anesthesia were included; patients receiving caffeine, regional anesthesia, or undergoing other surgical procedures were excluded. A uniform definition for apnea was used for all patients. Eleven risk factors were examined: gestational age, postconceptual age, birth weight, history of respiratory distress syndrome, bronchopulmonary dysplasia, neonatal apnea, necrotizing enterocolitis, ongoing apnea, anemia, and use of opioids or nondepolarizing muscle relaxants.

Results: Two hundred fifty-five of 384 patients from eight studies at four institutions fulfilled study criteria. There was significant variation in apnea rates and the location of apnea (recovery room and postrecovery room) between institutions (P < 0.001). There was considerable variation in the duration and type of monitoring, definitions of apnea, and availability of historical information. The incidence of detected apnea was greater when continuous recording devices were used compared to standard impedance pneumography with alarms or nursing observations. Despite these limitations, it was determined that: (1) apnea was strongly and inversely related to both gestational age (P = 0.0005) and postconceptual age (P < 0.0001); (2) an associated risk factor was continuing apnea at home; (3) small-for-gestational-age infants seemed to be somewhat protected from apnea compared to appropriate- and large-for-gestational-age infants; (4) anemia was a significant risk factor, particularly for patients > 43 weeks' postconceptual age; (5) a relationship to apnea with history of necrotizing enterocolitis, neonatal apnea, respiratory distress syndrome, bronchopulmonary dysplasia, or operative use of opioids and/or muscle relaxants could not be demonstrated.