Use of specific inhalation challenge in the evaluation of workers at risk for occupational asthma: a survey of pulmonary, allergy, and occupational medicine residency training programs in the United States and Canada

STUDY OBJECTIVES: To document the current practice of occupational asthma (OA) diagnosis and use of specific inhalation challenge (SIC). DESIGN, SETTING, AND PARTICIPANTS: A survey evaluating the current practice of SIC was mailed to 259 residency training programs in adult pulmonary diseases, allergy and immunology, and occupational medicine accredited in the United States and Canada during the year 2000. RESULTS: Forty-six percent (123 of 259 programs) participated. Ninety-two programs reported that patients with OA were seen during the previous year, 15 programs reported that SIC had been performed, and 10 programs reported that patients had been referred to other sites for SIC. A total of 259 patients underwent SIC. No unexpected adverse reactions were reported. Forty-one programs reported that they had been willing to undertake SIC but were unable to do so. The most common barriers cited were lack of availability of SIC within the evaluating institution, inability to locate a site for referral, concerns about reimbursement, and lack of an appropriate diagnostic reagent for use in SIC. Seventy-four programs indicated that SIC was useful, and 34 programs included training in the use of SIC was part of the residency curriculum. CONCLUSION: Although SIC is considered the "gold standard" for objective documentation of OA, the test is performed in only a few institutions in the United States and Canada. Many institutions indicate that SIC is not available, even when desired for patient management. Only a minority of participating residency training programs include SIC as a formal part of the training curriculum.     

Zidovudine in patients with human immunodeficiency virus (HIV) infection and Kaposi sarcoma. A phase II randomized, placebo-controlled trial

STUDY OBJECTIVE: To evaluate the toxicity, effects on immune function, antitumor effects, antiretroviral effects, and pharmacokinetics of zidovudine therapy in patients with early human immunodeficiency virus (HIV) infection and Kaposi sarcoma. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: National Institutes of Health, a referral-based research institution (single site). PATIENTS: Physician-referred volunteer patients with HIV infection, Kaposi sarcoma, CD4+ lymphocyte counts greater than 0.2 x 10(9)/L, and no systemic symptoms or history of opportunistic infection. Of 41 patients enrolled, 4 had not met all entry criteria and were therefore not evaluable. INTERVENTIONS: Patients were randomized to one of four treatment groups for an initial 12-week treatment period: oral placebo (9 patients); zidovudine, 250 mg orally every 4 hours (9 patients); zidovudine, 0.5 mg/kg body weight intravenously every 4 hours (9 patients); and zidovudine, 2.5 mg/kg intravenously every 4 hours (10 patients). After at least 12 weeks of therapy at their assigned dose, patients were treated with oral zidovudine, generally 250 mg every 4 hours, with a mean 42-week follow-up. MEASUREMENTS AND MAIN RESULTS: Anemia and granulocytopenia were the major toxicities. Significant increases in platelet counts and declines in serum HIV antigen and IgG and IgM levels occurred in treated patients. Treated patients were more likely than those on placebo to clear HIV from the cerebrospinal fluid. There were no differences in tumor progression or CD4+ or CD8+ lymphocyte counts among the groups. CONCLUSIONS: Zidovudine was well tolerated and had antiretroviral activity in patients with early HIV infection and Kaposi sarcoma but it had no significant effect on the extent of Kaposi sarcoma or on immune function.     

Anaplastic plasma cell myeloma and immunoblastic lymphoma. Clinical, pathologic, and immunologic comparison

To test whether highly anaplastic myeloma and immunoblastic lymphoma are truly identical disease processes, simultaneous series were compared in respect to cytomorphologic features, immunoglobulin content or secretion, clinical and laboratory findings, and patient survival. Although the series partially overlapped in each studied feature, different trends served to distinguish them. Of the 14 patients with myeloma, all were dead at two years, whereas six of the 22 patients with lymphoma were disease-free at 35 to 78 months. Only 50 percent of patients with myeloma received intensive chemotherapy, whereas all 19 patients with stage III or IV lymphoma received such therapy. Myelomas secreted predominantly IgA heavy chain rather than IgG and lambda light chain rather than kappa. Lymphomas contained predominantly IgM rather than IgG and kappa rather than lambda. There were no IgM myelomas and no IgA lymphomas. The shorter survival of patients with the extremely anaplastic form of myeloma, as compared with patients who had immunoblastic lymphoma, may relate, in part, to prior therapy for previous lower grade myeloma; however, intrinsic differences in the nature of these two disease processes are reflected in their disparate immunologic characteristics.     

Alpha 2 macroglobulin state in acute pancreatitis. Raised values of alpha 2 macroglobulin-protease complexes in severe and mild attacks.

Plasma values of C reactive protein, alpha 1 proteinase inhibitor, alpha 2 macroglobulin, and complexed alpha 2 macroglobulin have been determined in serial samples from 27 patients with acute pancreatitis. Complexed alpha 2 macroglobulin was measured by a novel enzyme linked immunosorbent assay with a monoclonal antibody specific for the complexed form. Patients with severe illness had lower concentrations of total alpha 2 macroglobulin and higher concentrations of complexed alpha 2 macroglobulin than those with mild illness, and in the majority of severe attacks the abnormal amounts of complexed alpha 2 macroglobulin were present throughout the eight days of the study. The proportion of total alpha 2 macroglobulin in the uncomplexed form, however, was generally greater than 90%, and in 26% of the mild cases completely normal concentrations of uncomplexed alpha 2 macroglobulin (greater than 99% of total) were found throughout the eight days of the study. This suggests that exhaustion of alpha 2 macroglobulin in plasma is unlikely to be a major factor in the pathogenesis of acute pancreatitis.     

Analyses of muscle spindles in the soleus of six inbred mouse strains

Adult muscle size and fibre‐type composition are heritable traits that vary substantially between individuals. We used inbred mouse strains in which soleus muscle mass varied by an order of magnitude to explore whether properties of muscle spindles can also be influenced by genetic factors. Skip‐serial cross‐sections of soleus muscles dissected from 15 male mice of BEH, BEL, C57BL/6J, DUH, LG/J and SM/J strains were analysed for number of muscle spindles and characteristics of intrafusal and extrafusal fibres following ATPase staining. The BEL and DUH strains determined the range of: soleus mean size, a 10‐fold difference from 2.1 to 22.3 mg, respectively; the mean number of extrafusal fibres, a 2.5‐fold difference from 497 to 1249; and mean fibre‐cross‐sectional area, three‐fold difference, e.g. for type 1 fibres, from 678 to 1948 μm². The range of mean proportion of type 1 fibres was determined by C57BL/6J (31%) and DUH (64%) strains. The mean number of spindles per muscle ranged between nine (LG/J) and 13 (BEL) (strain effect P < 0.02). Genetic correlations between spindle count and muscle weight or properties of extrafusal fibres were weak and not statistically significant. However, there was a strong correlation between the proportion of spindles with more than one bag₂ fibre and the proportion of extrafusal fibres that were of type 1, and strain‐dependent variation in the numbers of such spindles was statistically significant. The numbers of intrafusal fibres per spindle ranged from 2 to 8, with the most common complement of four found in 75.6% of spindles. There were no significant differences between the strains in the mean numbers of intrafusal fibres; however, the variance of the number was significantly less for the C57BL/6J strain than for any of the others. We conclude that abundance of muscle spindles and their intrafusal‐fibre composition are substantially determined by genetic factors, which are different from those affecting muscle size and properties of the extrafusal fibres.     

Unicompartmental knee arthroplasty: Is robotic technology more accurate than conventional technique?

BackgroundRobotic-assisted unicompartmental knee arthroplasty (UKA) with rigid bone fixation "can significantly improve implant placement and leg alignment. The aim of this cadaveric study was to determine whether the use of robotic systems with dynamic bone tracking would provide more accurate UKA implant positioning compared to the conventional manual technique.MethodsThree-dimensional CT-based preoperative plans were created to determine the desired position and orientation for the tibial and femoral components. For each pair of cadaver knees, UKA was performed using traditional instrumentation on the left side and using a haptic robotic system on the right side. Postoperative CT scans were obtained and 3D-to-3D iterative closest point registration was performed. Implant position and orientation were compared to the preoperative plan.ResultsSurgical RMS errors for femoral component placement were within 1.9 mm and 3.7° in all directions of the planned implant position for the robotic group, while RMS errors for the manual group were within 5.4 mm and 10.2°. Average RMS errors for tibial component placement were within 1.4 mm and 5.0° in all directions for the robotic group; while, for the manual group, RMS errors were within 5.7 mm and 19.2°.ConclusionsUKA was more precise using a semiactive robotic system with dynamic bone tracking technology compared to the manual technique.