Slowly resolving, chronic, and recurrent pneumonia.

Slowly resolving, chronic, and recurrent pneumonias are clinical patterns that are often misunderstood and mistreated. This article reviews the natural history, clinical presentation, roentgenography, bacteriology, and relation to underlying illnesses of each of these atypical forms of community-acquired pneumonia. Standard definitions are presented and provide the physician with a means to classify the pneumonias. Appropriate diagnostic evaluation and therapy are also discussed.     

Providing health care for Southeast Asian refugees

Approximately 850,000 Vietnamese, Cambodian, and Laotian refugees have come to the United States since the end of the war in Vietnam. Because of language, religious, and cultural differences, these refugees present a challenge for health care providers. Nurses who work with Southeast Asians must understand how their beliefs about illness causation and treatment affect their response to health care.     

Results of revision total knee arthroplasty performed for aseptic loosening

One hundred thirty-seven revision total knee arthroplasties (TKA) performed in 117 patients with failed aseptic metal-to-plastic knees over ten years (1974-1984) were studied to determine the long-term clinical and roentgenographic results and were compared to primary TKA. The mean age was 65 years (range, 32-90 years). Fifty-three percent had rheumatoid arthritis, and 47% had osteoarthritis. The mean interval from initial to revision TKA (129 knees) was four years (range, three months to 11 years) and from the first to second revision (seven knees) was 2.4 years (range, seven months to 5.5 years). The most common reasons for failure were loosening (73%), patellar complications (13%), and instability (10%). The mean follow-up time was 5.2 years (range, two to 12 years). Function, instability, motion, and pain all improved after revision TKA, but these improvements were significantly less than those seen after primary TKA. One-third of the patients still ambulated with crutches, a walker, or not at all. While mean postoperative flexion was 100 degrees, 24% could not flex to 90 degrees. Most patients (90%) were malaligned at the time of failure and remained so after revision (78%). The increased incidence of radiolucent lines (tibial, 61%; femoral, 24%) was not related to increased failure. Complications were not increased over primary TKA. The failure rate was 5.8% at 5.2 years, or approximately 1% per year. A successful clinical result was defined as a knee with mild or no pain, mild or no instability, and flexion to at least 90 degrees.(ABSTRACT TRUNCATED AT 250 WORDS)     

MR Lymphography with a Lymphotropic T1-Type MR Contrast Agent: Gd-DTPA-PGM

A model system of a paramagnetic lymphotropic MR contrast agent (Gd-DTPA labeled polyglucose associated macrocomplex, PGM) for T¹-weighted MR imaging of lymph nodes in rats and rabbits was evaluated. Pharmacokinetic (tissue accumulation) and MR imaging data (optimal dose and timing parameters) were obtained in normal rats (n = 88) after subcutaneous (SC) injection of paramagnetic, radiolabeled [111In]Gd-DTPA-PGM. A rabbit model of lymph node metastases (n = 8) was ultimately used to demonstrate the potential of MR imaging with Gd-DTPA-PGM for nodal tumor detection. Maximum concentrations of Gd-DTPA-PGM were found in popliteal and paraaortic lymph nodes within 24 h after SC administration, and highest lymph node SNR values were obtained by MR imaging at this time point. The optimum imaging dose was 6–12 μmol Gd/kg. Tumor-lymph node contrast increased from 0.0 ± 1.2 precontrast to 19.2 ± 6.5 (spoiled gradient echo sequence, TR 50/TE 7/flip angle 60°) postcontrast and conspicuity of nodal metastases was improved. Gd-DTPA-PGM accumulates in lymph nodes after SC administration and significantly enhances lymph node signal intensity of normal animals but not metastatic lymph nodes.     

Germ cell aneuploidy in zebrafish with mutations in the mitotic checkpoint gene mps1

Aneuploidy, resulting from chromosome missegregation during meiosis, is a major cause of human infertility and birth defects. However, its molecular basis remains incompletely understood. Here we have identified a spectrum of chromosome anomalies in embryos of zebrafish homozygous for a hypomorphic mutation in Mps1, a kinase required for the mitotic checkpoint. These aneuploidies are caused by meiotic error and result in severe developmental defects. Our results reveal Mps1 as a critical regulator of chromosome number in zebrafish, and demonstrate how slight genetic perturbation of a mitotic checkpoint factor can dramatically reduce the fidelity of chromosome segregation during vertebrate meiosis.     

X inactivation phenotype in carriers of Pelizaeus-Merzbacher disease: skewed in carriers of a duplication and random in carriers of point mutations

Pelizaeus-Merzbacher disease (PMD) is an X-linked recessive disease caused by coding sequence mutations in the PLP gene, sub-microscopic duplications of variable sizes including the PLP gene or very rarely deletions of the PLP gene. We analysed the X inactivation pattern in blood of PMD female carriers with duplications and with point mutations. In the majority of duplication carriers (7/11), the X chromosome bearing the duplication was preferentially inactivated, whereas a random pattern of X inactivation was detected in point mutation carriers (3/3), a deletion carrier (1/1), affected females (4/4) who did not have a recognised mutation and normal control females. However 2/5 non-carrier female relatives of patients with a duplication, had skewed X inactivation. The skewed pattern of inactivation observed in most duplication carriers and not in mutation carriers suggests a) that there is selection against those cells in which the duplicated X chromosome is active and b) other expressed sequences within the duplicated region rather than mutant PLP may be responsible. Since the skewed X inactivation did not segregate with the disease in two families and the pattern of X inactivation was variable among the duplication carriers, the pattern X inactivation is an unsuitable diagnostic tool for female carriers of PMD.     

Total Joint Replacement: Optimizing Patient Expectations

Rehabilitation of the patient who has undergone total hip or knee replacement embraces many facets of care, including prevention of complications, patient education, and a program of gradual resumption of normal functions. This program may be divided into three phases. In the perioperative phase, elimination of factors that contribute to morbidity will facilitate resumption of physical activities. In the interim phase (the first year following surgery), the patient's desire to return to full activities must be tempered by the goal of preserving for the longest possible time the mechanical-biologic construct of the joint replacement. Although a final functional result is usually achieved in the first 2 to 3 years following surgery, the patient must be followed up indefinitely. During this third phase of long-term assessment, the question of whether total joint arthroplasty was a success must be answered by the surgeon, by the patient, and by society.     

Development of a pediatric critical care transport team: experience at a military medical center

INTRODUCTION: A pediatric critical care transport program was initiated and organized at Naval Medical Center San Diego in January 1994. The primary goal of the program was to formally train military pediatric residents in the early stabilization and transport of the critically ill neonatal and pediatric patient. It was also felt that such a program would generate significant cost savings to the Department of Defense. We present the statistics, training protocol, and the cost savings. In addition, we surveyed previous residents who had been involved with this program to determine its perceived benefit. METHODS: In the first phase of this project, the pediatric critical care transport program database from January 1994 to December 1997 was reviewed. The number and types of transports were recorded. Next, we determined cost savings for the transport program for fiscal year 1996-1998 (the period for which fiscal data were available). In the second phase of this project, we sent surveys to the 23 graduating residents who had participated in the pediatric critical care transport program. The survey sought to determine the perceived value of the transport training experience and the degree to which that training is now being used. All investigators were blinded to the responses. Statistical analysis consisted of determining the percentage of each response. RESULTS: During the 4-year period reviewed, 404 transports were performed (198 neonatal and 206 pediatric). During fiscal year 1996-1998, there was a cost avoidance of $1,962 per transport. In the second phase, 91% of the surveys were returned and analyzed. The majority of residents were practicing in overseas or isolated communities. All respondents rated their experience in the pediatric critical care transport program as worthwhile and educational, and they complemented their training in the neonatal and pediatric intensive care units. Seventy-one percent of the respondents had transported a critically ill neonate or child to another facility within the last year. CONCLUSIONS: In summary, we report our experience with the development of a pediatric critical care transport program. The program was developed to provide military pediatric residents instruction and experience in the stabilization and transport of critically ill children. In addition, we were able to demonstrate a significant cost avoidance.