Synergistic actions of the vitamin D analogue MC 1288 and 15-deoxyspergualin in xenotransplantation

Abstract: The vitamin D analogue MC 1288 (20-epi-1α,25-dihydroxycholecalciferol) effectively postpones rejection of cardiac, intestinal, skin, and aortic allografts. MC 1288 binds to the vitamin D receptor and is thus assumed to exert its immunosuppressive effects via the same mechanisms as 1α,25-dihydroxycholecalciferol, the active form of vitamin D. 1α,25-Dihydroxycholecalciferol has been demonstrated to inhibit the production of various cytokines (interleukin-2, interferon-γ, granulocyte macrophage colony-stimulating factor, and interleukin-12) and to prevent B lymphocyte secretion of immunoglobulins. In the present study MC 1288 was evaluated for its ability to prevent rejection of mouse-to-rat cardiac xenografts, alone and in combination with 15-deoxyspergualin (DSG). Combined treatment with MC 1288 (given days -1 to 9) and DSG (given day -1 and onward) postponed rejection from day 3.0 (untreated recipients) until day 19.5. In rats treated with MC 1288 or DSG as monotherapy, rejection occurred after 3.0 and 7.5 days, respectively. Functioning grafts, obtained on day 9 from recipients treated with MC 1288 and DSG in combination, displayed an almost normal morphology without any obvious deposition of immunoglobulins in the vessels of the grafts and with just a few infiltrating cells. Thus, we have demonstrated synergistic actions of MC 1288 and DSG in delaying rejection of xenografts. Analysis of cellular infiltration, immunoglobulin deposition and graft survival times in the various treatment groups indicate a combined inhibitory effect of these two drugs on the level of macrophage effector function, direct or indirect via T lymphocytes, as well as on antibody production.     

Thoracotomy in the acute phase of staphylococcal lung disease

Two cases of staphylococcal lung disease in young infants are described. In each instance a life-threatening bronchopleural fistula in the acute phase was successfully managed by thoracotomy and suture repair. Offprint requests to: A. W. Auldist     

Epidural Epinephrine and Clonidine: Segmental Analgesia and Effects on Different Pain Modalities

Background: It is not known whether epidural epinephrine has an analgesic effect per se. The segmental distribution of clonidine epidural analgesia and its effects on temporal summation and different types of noxious stimuli are unknown. The aim of this study was to clarify these issues.

Methods: Fifteen healthy volunteers received epidurally (L2-L3 or L3-L4) 20 ml of either epinephrine, 100 micro gram, in saline; clonidine, 8 micro gram/kg, in saline; or saline, 0.9%, alone, on three different days in a randomized, double-blind, cross-over fashion. Pain rating after electrical stimulation, pinprick, and cold perception were recorded on the dermatomes S1, L4, L1, T9, T6, T1, and forehead. Pressure pain tolerance threshold was recorded at S1, T6, and ear. Pain thresholds to single and repeated (temporal summation) electrical stimulation of the sural nerve were determined.

Results: Epinephrine significantly reduced sensitivity to pinprick at L1-L4-S1. Clonidine significantly decreased pain rating after electrical stimulation at L1-L4 and sensitivity to pinprick and cold at L1-L4-S1, increased pressure pain tolerance threshold at S1, and increased thresholds after single and repeated stimulation of the sural nerve.     

Complications in infants undergoing surgery for congenital cataract in the first 12 weeks of life: is early surgery better?

PURPOSE: To determine if there is an association between the timing of surgical intervention for congenital cataract within the first 12 weeks of life and the prevalence of postoperative complications. METHODS: We performed a retrospective review of records from 1990 to 2000 of infants who underwent surgery for congenital cataract within the first 12 weeks of life. Eighty eyes in 55 children were involved with a minimum follow up of 6 months. Bilateral cataracts were present in 25 and monocular cataracts in 30 infants. A limbal approach lensectomy-vitrectomy was performed in all infants. Children with aphakia were rehabilitated with contact lens or glasses. Operative and postoperative complications-including glaucoma, nystagmus, strabismus, retinal detachment, and posterior capsule opacification/secondary membranes-were recorded. Ocular and systemic associations were noted. Statistical analysis was carried out with classification and regression trees (CART). RESULTS: The mean age at the time of surgery was 31.5 +/- 23.3 days (median, 26.5; range, 2 to 84). Mean follow up from the time of surgery was 2.85 +/-1.9 years (median, 2; range, 0.5 to 8). Persistent fetal vasculature (persistent hyperplastic primary vitreous) was present in 14 eyes. One infant with bilateral persistent fetal vasculature had bilateral retinal dysplasia and was excluded from the analysis. Glaucoma developed in 12 infants (22%); nystagmus was present in 18 infants (33%); strabismus developed in 28 infants (52%); and secondary membranes developed in 7 eyes (13%). CART analysis suggests that glaucoma is more prevalent in infants when the surgery was performed between 13.5 and 43 days of life (CART = 0.370); nystagmus when surgery is performed between 48 and 84 days of life (CART = 0.500); strabismus when surgery is performed between 55.5 and 84 days of life (CART = 0.600); and secondary membranes when surgery is performed between 26.5 and 40 days of life (CART = 0.4). CONCLUSIONS: Our data suggest that the first 2 weeks of life comprise the most favorable time for decreasing postoperative complications resulting from surgical intervention for infants presenting with cataracts within the first 12 weeks of life.     

The effect of pre-vertebroplasty tumor ablation using laser-induced thermotherapy on biomechanical stability and cement fill in the metastatic spine

A biomechanical study comparing simulated lytic vertebral metastases treated with laser-induced thermotherapy (LITT) and vertebroplasty versus vertebroplasty alone. To investigate the effect of tumor ablation using LITT prior to vertebroplasty on biomechanical stability and cement fill patterns in a standardized model of spinal metastatic disease. Vertebroplasty in the metastatic spine is aimed at reducing pain, but is associated with risk of cement extravasation in up to 10%. Six pairs of fresh-frozen cadaveric thoracolumbar spinal motion segments were tested in axial compression intact, with simulated metastases and following percutaneous vertebroplasty with or without LITT. Canal narrowing under load, pattern of cement fill, load to failure, and LITT temperature and pressure generation were collected. In all LITT specimens, cement filled the defect without extravasation. The canal extravasation rate was 33% in specimens treated without LITT. LITT and vertebroplasty yielded a trend toward improved posterior wall stability (P = 0.095) as compared to vertebroplasty alone. Moderate rises in temperature and minimal pressure generation was seen during LITT. In this model, elimination of tumor by LITT, facilitates cement fill, enhances biomechanical stability and reduces the risk of cement extravasation.     

Alcohol and drug use following traumatic brain injury: A prospective study

Primary objectives: To establish pre-morbid alcohol and drug use in persons with TBI, relative to controls, investigate how patterns of substance use change over time following TBI and identify factors associated with heavy post-injury substance use.

Methods and procedures: The Alcohol Use Disorders Identification test (AUDIT) and Drug Abuse Screening Test (DAST) was completed by 121 hospital inpatients with TBI, documenting pre-injury alcohol and drug use, and 133 demographically similar controls. Participants with TBI completed these measures and the Hospital Anxiety and Depression Scale (HADS) again 1 and 2 years post-injury and 76 also completed them at 3 years.

Results: Participants with TBI showed similar levels of drug and alcohol use to controls pre-injury, with 31.4% of the TBI group and 29.3% of controls drinking at hazardous levels. Alcohol and drug use declined in the first year post-injury, but increased by 2 years post-injury, with only 21.4% of participants with TBI reporting abstinence from alcohol and 25.4% drinking at hazardous levels. Only 9% showed a drug problem, but 24% had returned to some drug use. Those showing heavy alcohol use post-injury were young, male and heavy drinkers pre-injury. Drug and alcohol use was similar at 3 years post-injury.

Conclusions: More active intervention is needed to reduce alcohol and drug use following TBI.     

Characteristics of calcaneal bone infarction: an MR imaging investigation

Objective. Bone infarction (BI) of the calcaneus is an uncommon entity which has received little mention in the recent literature. In this paper, we review the MR images of six calcanei with BI, which demonstrate a pattern of presentation that may explain the etiology of BI at this unusual location. Design. A retrospective review was performed of the transcribed reports of the foot or ankle MR examinations at our institution. MR images of examinations with any marrow signal abnormality were reviewed for presence of BI and its distribution. Patients. Based on MRI criteria, four patients had calcaneal BI (none biopsy proven); they ranged in age from 37 to 51 years old. Two patients were diagnosed with systemic lupus erythematosus, one with fibrositis, and another with polymyositis. All were treated with corticosteroids. Results. Six calcanei (in four patients) contained a region of calcaneal BI. In five of the six, the lesions were entirely or predominantly located in the posterior half of the calcaneus. Conclusion. Two theories are proposed which may explain why BI predominantly occurs in the posterior half of the calcaneus. First, the convergence of the recurrent intraosseous calcaneal vessels may occasionally produce the equivalent of a single dominant vessel that is more prone to vascular accidents. Secondly, the region between the recurrent and the epiphyseal vessels may act as a watershed zone, increasing its susceptibility to ischemia.