Antibody responses of cattle to outer membrane proteins of Pasteurella multocida A:3

OBJECTIVE: To quantify the serum antibody responses to Pasteurella multocida A:3 outer membrane proteins (OMP) for cattle vaccinated with the homologous serogroup and to correlate those responses with the extent of experimentally induced pneumonia. ANIMALS: 29, 5- to 8-month-old beef-type calves. PROCEDURE: Calves were vaccinated SC or by aerosal exposure on days 0 and 7 with live or killed P multocida or phosphate-buffered saline solution (control) and subsequently challenge exposed with virulent P multocida. Antibody responses to P multocida A:3 outer membranes were quantified, using an ELISA. Antibody responses to individual OMP were detected by immunoblot analysis (western blot) and were quantified by densitometry. Antibody responses were compared among groups of calves and for various times after vaccination. Regression analyses were used to determine whether significant correlations existed between lesion scores and antibody responses to either whole outer membranes or to individual OMP. RESULTS: By ELISA, antibody responses to outer membranes for calves aerosol vaccinated with live P multocida were significantly (P < 0.05) greater than those for control calves or for killed P multocida vaccinates. There was a significant (P < 0.05) correlation between lesion score and antibody responses to outer membranes. By western blotting and densitometry, antibodies to 11 prominent OMP (100, 97, 90, 85, 74, 53, 46, 35, 32, 21, and 16 kd) were identified and quantified. In experiment 1, SC vaccination with live P multocida increased antibody binding to all protein bands except 85-, 74-, and 35-kd bands. Aerosol vaccination with live P multocida stimulated increases in antibody binding to all bands except 100 and 16 kd. Antibody responses to the 97-, 90-, 74-, and 35- kd bands were significantly (P < 0.05; greater for live aerosol vaccinates than for control calves. In experiment 2, antibody responses were not different between the killed P multocida vaccinates or control calves Antibody responses for live P multocida aerosol vaccinates were significantly (P < 0.05) greater than those for control calves for the 100-, 90-, 85-, 74-, 53-, 35-, and 16-kd bands. Regression analyses indicated significant correlations (P < 0.05) between lesion score and antibody responses to the 100-, 90-, 53-, 46-, 35-, and 32-kd OMP. CONCLUSIONS: Several OMP of P multocida type A:3 may be important for stimulating immunity to the organism in cattle.     

The correlation of the radiologic extent of lung transplantation edema with pulmonary oxygenation

OBJECTIVE: The study set out to evaluate the relationship between the efficiency of pulmonary oxygenation and the extent of the reimplantation response as revealed on chest radiography after bilateral lung transplantation. MATERIALS AND METHODS: Postoperative chest radiographs of 31 patients who had undergone bilateral lung transplantation were evaluated for the extent of the reimplantation response. For each patient, the contemporaneous oxygenation indexes (partial pressure of oxygen in arterial blood divided by fraction of inspired oxygen) were calculated and correlated with a radiographic score produced from the evaluation of chest radiographs. RESULTS: The method of evaluating chest radiographs for the extent of the reimplantation response was shown to be reproducible. Although mean oxygenation indexes were found to decrease with increasing radiographic scores, this trend was not statistically significant. CONCLUSION: Although the extent of the reimplantation response on the early postoperative chest radiography inversely correlated with the oxygenation efficiency of the transplanted lungs, this finding was not statistically significant.     

Effects of the major Pasteurella multocida porin on bovine neutrophils

OBJECTIVE: To evaluate in vitro effect of the major fraction of outer membrane proteins of Pasteurella multocida with porin-like activities on some biological functions of bovine neutrophils. ANIMALS: Neutrophils from 5 adult cattle. PROCEDURE: Variations in such biological processes as actin polymerization and chemotaxis and evaluation of hydrogen peroxide attributable to variable concentrations of P multocida were recorded and compared. Data were obtained, using the porin and lipopolysaccharide (LPS) isolated from a strain of P multocida cultivated in brain-heart infusion (BHI) broth. Various concentrations of porin and LPS were analyzed to evaluate changes in functional activation and microbicidal activity of bovine neutrophils. RESULTS: The 37.5-kd major polypeptide of the outer membrane of P multocida was isolated. Presence of this porin was significantly correlated with variations of some biological functions of bovine neutrophils. These immunocompetent cells had a concentration-dependent increase in actin polymerization and chemotactic activity. A concentration-dependent variation in the oxidative burst also was observed. CONCLUSIONS: The porins of gram-negative bacteria affect several biological functions of cells involved in the immune response as well as in inflammation. Significant correlation of results of in vitro experiments also was identified between porin and LPS effect. Pretreatment of bovine neutrophils with various concentrations of porin always caused a concentration-dependent increase in examined biological activities.     

Bone biopsy

Neoplasia is the most common cause of bone lesions in small animals. A definitive diagnosis is required to determine an accurate prognosis and to formulate effective treatment options. Each lesion should be characterized as accurately as possible by evaluation of patient history, signalment, laboratory findings, and the radiographic appearance and location of the lesion. A bone biopsy is recommended for lesions that require histological characterization or culture and susceptibility testing. The biopsy technique of choice should be properly planned to provide accurate sampling of the lesion, to produce the least morbidity possible, and to avoid interferences with future surgical treatment. Approximately 94% of lesions can be definitively diagnosed on the first biopsy attempt if the center of the lesion and the transitional zone between the lesion and normal bone are accurately sampled. Use of a guide wire and prebiopsy radiographs help ensure accurate sampling. A diagnosis of reactive bone is usually an indication for a second biopsy or for close clinical and radiographic monitoring of the lesion.     

Effect of age and apoptosis on the mouse homologue of the huWRN gene

Early lesion formation was examined in 13 calves inoculated intranasally with 2 x 10(7) colony-forming units of Mycobacterium bovis and killed either singly or in pairs at intervals of < or = 7 days from post-inoculation day (pid) 3 to pid 42. Immunological examinations were carried out before and after infection, and sequential necropsies were performed. M. bovis was recovered as early as pid 3, from the upper respiratory tract mucosae, retropharyngeal lymph nodes and caudal lung lobe. Gross tuberculous lesions were detected in both the upper respiratory tract mucosae and in the lungs of the calves killed from pid 14 onwards. Lesions were also present in the lymph nodes draining these areas. On histological examination, neutrophils appeared to play a key role in the earliest stages of lesion formation, and lesion mineralization was observed for the first time at pid 35. The contemporaneous development of lesions and cellular immunity, as demonstrated by in-vitro lymphocyte proliferation and interferon-gamma assay responses, provided further evidence of the role of immunopathogenic mechanisms in the development of bovine tuberculosis.     

Timing waveform analysis

PURPOSE: To determine the diagnostic yield of routine admission chest radiographs in patients with acute gastrointestinal (GI) hemorrhage and clinical predictors of radiographic abnormalities. PATIENTS AND METHODS: The study was a retrospective series of 202 adult patients with GI hemorrhage admitted to intensive care units at an academic medical center. Routine admission chest radiographs were obtained in 161 patients. These radiographs were reviewed by a study radiologist blinded to the study purpose. The radiologist scored radiographic abnormalities into categories of "minor" or "major," "new" or "previously known," and "with an intervention" or "without an intervention." Nominal logistic regression explored the data for clinical features that identified patients with major new radiographic abnormalities with or without an intervention. RESULTS: Minor radiographic abnormalities were noted in 23 (14.3%) patients, of whom 17 (10.6%) patients had "new" (previously unknown) abnormalities. No minor abnormality prompted a therapeutic or diagnostic intervention. Major radiographic abnormalities were detected in 21 (13.0%) patients, of whom 19 (11.8%) had new findings. Major new findings prompted interventions in only 9 (5.6%) of patients. A history of lung disease and an abnormal lung physical examination predicted major new radiographic findings (P = 0.0001, sensitivity 79%, negative predictive value 96%). These variables also identified major new abnormalities that prompted interventions (P = 0.007, sensitivity 89%, negative predictive value 99%). Use of the logistic regression model to select patients for admission chest radiographs decreased charges from $1,068 to $580 for each detected major new radiographic abnormality and from $2,254 to $1,087 for major new radiographic abnormalities that prompted an intervention. CONCLUSION: These data indicate that routine chest radiographs have a low yield in detecting major new radiographic abnormalities in patients with acute GI hemorrhage. Clinical criteria, available at the time of admission, may be useful for selecting patients for chest radiographic evaluations.     

Effect of sodium ion coupled nutrient transport on intestinal permeability in chronically catheterised rats

Diatomaceous earth is a noncrystalline form of silica; in processing, calcining leads to formation of cristobalite, a form of crystalline silica. Four hundred ninety-two currently employed diatomaceous earth workers in a large mine and processing facility had chest radiographs performed and interpreted by the International Labour Office (ILO) system. Two hundred sixty-seven subjects underwent spirometry testing. Exposure indices for total dust (largely diatomaceous earth) and cristobalite were reconstructed for each individual based upon personnel records. Analysis demonstrated the following prevalences of radiographic findings: 5% had ILO scores > or = 1/0, and 25% had scores of 0/1 or higher. Regression analyses showed that there was a relationship between both total cristobalite exposure and total dust (largely diatomaceous earth) exposure and the ILO score. Radiographic patterns are not typical of those of classic silicosis. Linear regression analyses for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio did not demonstrate a relationship between cumulative exposure and lung function. Such analyses were performed using all subjects and stratified by smoking status. There were differences in spirometric data according to radiographic ILO category, but the results were inconsistent and did not permit determining if physiologic changes are associated with radiographic change or if this is due to confounding. Overall, the study suggests that diatomaceous earth pneumoconiosis (radiographically defined) is an entity distinct from silicosis. Recent exposure levels may produce radiographic abnormalities but do not lead to demonstrable physiologic effect. The prevalence of the disorder has diminished markedly in response to modern dust control measures. Ongoing medical surveillance is recommended in workers with potential exposure to significant quantity of material.     

The insulin receptor substrate 1 associates with phosphotyrosine phosphatase SHPTP2 in liver and muscle of rats

OBJECTIVE: To determine efficacy of a vaccine containing modified-live bovine viral diarrhea virus (BVDV) type 1 for protecting pregnant cows and their fetuses against virulent heterologous BVDV type 1. DESIGN: Randomized controlled cohort study. ANIMALS: 18 yearling beef heifers seronegative for BVDV and negative when tested for BVDV by virus isolation. PROCEDURE: Cattle were randomly assigned to control (unvaccinated; n = 6) or vaccinated (12) groups. Vaccinated heifers were given a combination vaccine containing modified-live BVDV type 1 comprising a cytopathic (NADL) strain. All 18 heifers were then bred and challenge-exposed between 70 and 75 days of gestation with BVDV type 1, administered intranasally. Cattle were monitored, and infection status of offspring was determined after parturition. Antibody concentrations of vaccinated and control heifers were also monitored. RESULTS: All 6 calves from control heifers had positive results on multiple virus isolation tests and were considered persistently infected. In comparison, only 2 calves from vaccinated cows had positive results on virus isolation tests and were considered persistently infected. One vaccinated heifer aborted, but the fetus was not persistently infected, and the abortion was not attributed to BVDV infection. CLINICAL IMPLICATIONS: Analysis of these data indicated that a single dose of a modified-live NADL-derived BVDV type 1 vaccine will confer protection to dams and their fetuses against challenge-exposure to heterologous BVDV type 1 organisms.     

Passive protection of gnotobiotic calves using monoclonal antibodies directed at different epitopes on the fusion protein of bovine respiratory syncytial virus

Two neutralizing, fusion-inhibiting bovine monoclonal antibodies (MAbs; B4 and B13) directed at different epitopes on the fusion protein of respiratory syncytial virus (RSV) protected the lungs of gnotobiotic calves from RSV infection. The MAbs were administered intratracheally 24 h before the calves were challenged with bovine RSV. A third, nonneutralizing, non-fusion-inhibiting but complement-fixing MAb, B1, provided no significant protection against infection, and the disease was not exacerbated. Pneumonic consolidation and mean virus titer in lung 7 days after challenge were significantly lower in calves given the fusion-inhibiting MAbs than in either control calves or those given MAb B1. The proliferative bronchiolitis with syncytial formation and widespread distribution of RSV antigen in the lower respiratory tract of the B1-treated and control calves were indistinguishable and typical of experimental bovine RSV infection. Syncytia were markedly absent, and little or no viral antigen was detected in either the B4- or B13-treated calves.     

High-resolution CT of the lung: determination of the usefulness of CT scans obtained with the patient prone based on plain radiographic findings

OBJECTIVE: We assessed the usefulness of chest radiographs for predicting whether high-resolution CT scans obtained with the patient prone would be valuable in assessing suspected diffuse lung disease. MATERIALS AND METHODS: In 100 consecutive patients undergoing high-resolution CT, findings on plain chest radiographs were classified as normal, possibly abnormal, or abnormal. CT scans obtained with the patient supine were assessed for the presence and distribution of lung abnormalities without knowledge of the plain radiographic classification. A second review of the CT scans was done with equal numbers of scans obtained with the patient prone and with the patient supine. The usefulness of the CT scans obtained with the patient prone for detecting lung disease was determined and related to the plain radiographic classifications. RESULTS: High-resolution CT scans obtained with patients prone were helpful in excluding or confirming posterior lung abnormalities in 10 (28%) of 36 patients who had normal findings on chest radiographs, five (28%) of 18 patients who had possibly abnormal findings on chest radiographs, and only two (4%) of 46 patients who had abnormal findings on chest radiographs. The proportion of patients who benefited from high-resolution CT scans obtained with the patient prone was significantly lower among the patients with abnormal findings on chest radiographs than among the patients with normal (p = .008) or possibly abnormal (p = .02) findings on chest radiographs. The two patients with abnormal findings on radiographs in whom CT scans obtained with the patient prone were helpful had minimal radiographic abnormalities. CONCLUSION: In patients with suspected diffuse lung disease, obtaining high-resolution CT scans with the patient prone may be useful when chest radiographs show normal findings, possibly abnormal findings, or minimal abnormalities indicative of diffuse lung disease. However, such scans are of little value in patients whose radiographs show abnormalities indicative of diffuse lung disease.     

A bovine model of vaccine enhanced respiratory syncytial virus pathophysiology

A critical issue has been the observation that vaccination of children with a formalin-inactivated respiratory syncytial virus (RSV) vaccine is associated with disease enhancement. We have taken advantage of bovine RSV and our experience with this disease in calves to develop a natural model that parallels human disease. Using formalin-inactivated bovine RSV vaccine calves were either sham-vaccinated/infected, vaccinated/infected, or vaccinated/sham-infected and their clinical signs, pulmonary function, and histological lung lesions quantitatively scored. Interestingly there was significantly greater disease in vaccinated/infected calves and histological lesions in calves were similar to those of affected children. Finally, we note that vaccination did not induce neutralizing antibodies, but IgG antibodies were detected by ELISA. Our model of RSV enhanced disease is important because it provides quantifiable evidence of disease severity that can be applied to evaluate the mechanisms of immunopathology and the safety of candidate RSV vaccines.     

Radiographic outcome of recent-onset rheumatoid arthritis: a 19-year study of radiographic progression

OBJECTIVE: To describe the longitudinal radiographic course of rheumatoid arthritis (RA), and to identify and quantitate predictors of radiographic progression. METHODS: This prospective, longitudinal study of radiographic progression and clinical predictors of RA involved 256 patients with RA who were seen within the first 2 years of disease (mean 0.77 years) and were followed up for up to 19 years. Participants underwent a total of 6,278 clinical assessments (mean 24.5) and 934 paired radiographs (mean 3.1, range 2-6). Clinical assessments at every visit included determination of the erythrocyte sedimentation rate (ESR), grip strength, pain scores, tender joint counts, and anxiety and depression measurements. Regression analyses utilized time-integrated predictors. RESULTS: Overall, radiographic progression rates, as measured by the summary Sharp scores, appeared constant over the course of RA. The strongest correlate of progression was the time-integrated ESR (rho=0.53). This association grew stronger with time. At 0-5 years, 5-10 years, 10-15 years, and 15-20 years, correlations were 0.40, 0.50, 0.65, and 0.74, respectively, and for the period 10-20 years, the correlation was 0.67. In multivariate models, the mean ESR, mean grip strength, rheumatoid factor positivity, and tender joint count were independent predictors of radiographic progression. CONCLUSION: Radiographic damage occurs at a constant rate in RA, and is not greater early in RA or reduced later in the course of the illness. Acute-phase reactants are, by far, the strongest determinants of progression.     

Effect of a commercially available nonspecific immunomodulating biologic product on health of neonatal calves

OBJECTIVE: To determine whether treatment with a commercially available nonspecific immunomodulating biologic product would alter the clinical course of disease in neonatal calves. DESIGN: Systematically randomized, controlled cohort study. ANIMALS: 200 Holstein bull calves 1 to 5 days old. PROCEDURE: Assessments were performed that included evaluation of fecal consistency, attitude, appetite, and hydration status. Calves with abnormal results were enrolled in the study. Calves were systematically assigned to control or treatment groups (100 calves/group). Calves in the treatment group were given a single i.v. injection of the biologic product at the time of enrollment, whereas control calves were not given the product. Calves were assessed daily for 5 days to evaluate fecal consistency, attitude, appetite, hydration status, and rectal temperature. Assessments were made without knowledge of group assignment. RESULTS: Treatment with the immunomodulating product was not associated with a decrease in the number of calves that had moderate or severe departures from clinically normal conditions for attitude, appetite, or hydration on days 1 though 5, compared with control calves. Fecal consistency scores were significantly greater for treated calves on days 1 (P = 0.03) and 5 (P = 0.02), compared with scores for control calves. CLINICAL IMPLICATIONS: Administration of the nonspecific immunomodulating biologic product did not significantly affect outcome of clinical disease for calves in the treated group, compared with calves in the control group. On the basis of results of this study, we cannot recommend use of the nonspecific immunomodulating biologic product for the treatment of undifferentiated diarrheal disease in neonatal calves.     

Ectopic gastric mucosa in the upper esophagus: detection and radiographic findings

PURPOSE: To detect and characterize the appearance of islands of ectopic gastric mucosa in the upper esophagus at routine examination of the upper gastrointestinal (GI) tract. MATERIALS AND METHODS: Well-distended upper esophagus was documented with spot radiographs obtained with routine double-contrast examination performed after administration of high-density barium in nine patients. Detected lesions were confirmed by means of endoscopy and biopsy. RESULTS: Twelve lesions were detected. Radiographic findings were characterized by either a discrete, shallow depression surrounded by a subtle, rimlike elevation on double-contrast images or by a pair of small indentations on the same wall on full-column, single-contrast images at the level of the thoracic inlet. Endoscopic examination revealed well-circumscribed areas of reddish mucosa located 15-26 cm from the incisors. CONCLUSION: Ectopic gastric mucosa in the upper esophagus is easily demonstrated at routine examination of the upper GI tract. Diagnosis can be based on location and characteristic radiographic appearance.     

Angiogenesis and expression of tenascin after transmural laser revascularization

OBJECTIVE: To evaluate the impact of maternal antibodies after challenge exposure of baby pigs with a homologous serovar of Haemophilus parasuis. ANIMALS: 7 gilts and their litters from a high health status farm. PROCEDURE: Gilts were vaccinated twice with a commercial bacterin that contained H parasuis serovar 4 and 5 or, as a control, adjuvant only. A group of pigs was also vaccinated similarly before challenge exposure. After early and late challenge exposure at 3 and 4 weeks, respectively, all pigs from vaccinated gilts were evaluated for clinical signs of infection, lesions, and antibody titer. RESULTS: All pigs coming from control gilts had severe signs of H parasuis infection. Macroscopic lesions included polyserositis and pneumonia, and bacteriologic examination confirmed H parasuis as the etiologic agent. Vaccinated pigs born to vaccinated gilts did not have clinical signs of disease. However, some vaccinated pigs born to control gilts had signs of nervous system dysfunction and lameness. There was no difference in lesion scores between early or late challenge exposure, but lesions scores for pigs from vaccinated and control gilts were different (P < 0.01). CONCLUSIONS: Under these experimental conditions, immune-naive and vaccinated pigs from vaccinated gilts were protected against systemic lesions when challenge exposed with a virulent strain of H parasuis. CLINICAL RELEVANCE: Vaccination of the gilt and pigs protects the latter from polyserositis, but results are not different from those for nonvaccinated pigs from vaccinated gilts. Maternal antibodies did not seem to interfere with vaccination of pigs at 1 and 3 weeks of age.     

Clinical and immunologic responses of vaccinated and unvaccinated calves to infection with a virulent type-II isolate of bovine viral diarrhea virus

OBJECTIVE: To determine efficacy of a modified-live type-I isolate of bovine viral diarrhea virus (BVDV) vaccine in protecting calves from infection with a virulent type-II isolate, and to determine which type of immune response (i.e., humoral or cellular) correlates with protection. DESIGN: Prospective study. ANIMALS: 28 neonatal Holstein and Holstein-cross calves. PROCEDURE: Within 18 hours of birth, calves received maternal colostrum or were fed pooled colostrum. On days 7 to 10 after birth, calves were determined to be seropositive (n = 16) or seronegative (12) for antibodies to BVDV on the basis of ELISA and virus neutralization test results. Seropositive and seronegative 10- to 14-day-old calves were then given a combined vaccine that contained a modified-live type-I isolate of BVDV or a similar vaccine that lacked protection against bovine viral diarrhea. All calves were inoculated intranasally approximately 21 days after vaccination with a virulent type-II isolate of BVDV. Clinical and immunologic variables, including clinical scores, rectal temperatures, results of CBC with lymphocyte subset analysis, antibody responses, and cell-mediated immune responses, were monitored for 14 days after inoculation. RESULTS: Seronegative-unvaccinated calves developed severe disease and required euthanasia. Vaccination of seronegative calves with a modified-live type-I isolate had a disease-sparing effect as did passive transfer of colostral antibodies to BVDV. Clinical scores were not significantly different between seropositive-vaccinated and seropositive-unvaccinated calves after viral inoculation. CLINICAL IMPLICATIONS: A single dose of a modified-live type-I isolate of BVDV vaccine protects young calves from clinical signs of disease associated with type-II isolates.     

Prevalence of antibodies to lipid A in Danish cattle

A cross-sectional study was performed on the occurrence of IgG antibodies to lipid A of the Gram-negative bacterial lipopolysaccharide (LPS, endotoxin) on serum of 2272 cattle distributed on 19 Danish dairy herds. The relationship between the concentration of antibodies to lipid A (ALI) and age, herd, pregnancy rate and occurrence of mastitis, bovine virus diarrhoea (BVD), reproductive and digestive disorders, diarrhoea, pneumonia, foot disorders, various infections and traumatic udder lesions was investigated. ALI generally was low in calves and increased during their first 1.5 years of life to a steady state, which could be altered by the occurrence of disease. There were significant differences in the mean ALI among the herds (P < 0.001). High ALI was associated with a low herd pregnancy rate, to preceding occurrence of mastitis (P < 0.048), BVD (P < 0.01), reproduction diseases (P < 0.041) and digestion disorders (P < 0.064) in animals older than 2 years. The calf mortality rate was not associated to ALI and there was no correlation between the ALI in calves and their dams. The occurrence of high ALI levels on a herd basis may be an indication of increased challenge or enhanced immunological defense to Gram-negative bacteria or endotoxin.     

Applications of PET in lung cancer

An estimated 180,000 new cases of lung cancer will be diagnosed in the United States this year, and lung cancer accounts for approximately 25% of all cancer deaths. The overall 5-year survival rate is 14%, and this has not changed over the past several decades. Lung cancer diagnosis and treatment is a major health problem globally. Most lung cancers are detected initially on chest radiographs, but many benign lesions have radiologic characteristics similar to malignant lesions. Thus, additional studies are required for further evaluation. Computed tomography (CT) is most frequently used to provide additional anatomic and morphologic information about the lesion, but it is limited in distinguishing benign from malignant abnormalities in the lung, pleura, and mediastinum. Because of the indeterminate results from anatomic imaging, biopsy procedures including thoracoscopy and thoracotomy may be used even through one-half of the lesions removed are benign and do not need to be removed. FDG-PET imaging provides physiologic and metabolic information that characterizes lesions that are indeterminate by CT and that accurately stages the distribution of lung cancer. Exploiting the fundamental biochemical differences between cancer and normal tissues, FDG imaging takes advantage of the increased accumulation of FDG in transformed cells. FDG-PET is very sensitive (approximately 95%) for the detection of cancer in patients who have indeterminate lesions on CT. The specificity (approximately 85%) of PET imaging is slightly less than the sensitivity because some inflammatory processes such as active granulomatous infections accumulate FDG avidly. The high-negative predictive value of PET suggests that lesions considered negative on the study are benign, biopsy is not needed, and radiographic follow-up is recommended. Several studies have documented the increased accuracy of PET compared with CT in the evaluation of the hilar and mediastinal lymph node status in patients with lung cancer. If the mediastinum is normal on PET imaging and there is no other evidence of metastatic disease, the patient has a thoracotomy. If the mediastinum is abnormal on PET imaging, mediastinoscopy is performed with the PET images providing the lymph node stations to target. Whole-body PET studies detect metastatic disease that is unsuspected by conventional imaging and demonstrate some of the anatomic abnormalities detected by CT to be benign lesions. Management changes have been reported to occur in up to 41% of patients based on the results of the whole-body studies.     

Peer approaches for increasing HIV awareness on a college campus

PURPOSE: To compare the accuracy of clinical examination performed with bitewing radiographs or clinical examination using tooth separation to identify carious lesion activity. MATERIALS AND METHODS: 320 surfaces from 40 bitewing radiographs were examined for approximal caries on the maxillary and mandibular primary molars of 20 patients 3-10 years old. The patients were divided into three groups: (1) Absence of the permanent first molar; (2) Partial eruption of the permanent first molar; and (3) Full eruption of the permanent first molar. Two examiners evaluated the radiographs using a megascope, a magnifying glass (x2), and an amplifying image screen. Approximal radiolucencies were identified on 72 surfaces. Following the radiographic examinations, the two examiners performed conventional clinical inspection using a No. 4 dental mirror, a No. 5 dental explorer, and an air-water syringe, with artificial light and relative isolation. The separation method was performed with elastic bands, which were removed after 24 hours, and the clinical examination conducted as in the non-separation group. RESULTS: The correlation between the extension of interproximal radiolucent lesions in primary dentition and their clinical diagnoses following separation of the teeth, was similar to findings on literature evaluating the permanent dentition. On radiographic findings for enamel lesions, white spots predominated both in the inner (100%) and in the outer (94%) half of enamel upon clinical examination with separation of teeth. For radiolucent lesions in dentin, on the other hand, cavities predominated over white spot lesions (84%). In Groups 1 and 2 (young primary), white spots occurred in cases where the radiolucent lesions reached the dentin (15% and 25%), similar to findings for young permanent teeth. Clinical diagnosis performed with the mechanical separation of teeth cannot be considered conclusive for the primary dentition.     

Giant cell tumors of bone

Giant cell tumor is a lesion that usually presents with a radiographically characteristic appearance in a predictable location and patient population. It has a few rare presentations such as pulmonary metastases and multifocal lesions. Prognosis of ultimate tumor behavior is dependent on surgical staging (which requires careful radiographic analysis to detect cortical breakthrough and joint involvement) and type of treatment. The recurrence rate is relatively high with simple curettage but decreases with adjuvant treatment at the tumor site. Optimal therapy for the more aggressive lesions is wide resection, but compromise is frequently required when such a resection would sacrifice joint function because of the subarticular location of the giant cell tumor. Radiation therapy is reserved for surgically inaccessible or otherwise inoperable lesions because of a relatively poor radiosensitivity and concerns about induction of high grade sarcomas. Radiographic follow-up evaluation for recurrence is recommended for approximately 5 years but may be difficult to interpret in individual patients because of an overlap in the appearance of healing and recurrence.