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Biomedical subjects

S G Jennings

Publications and source records attributed to S G Jennings.

16 recordsLinked to original sources
PubMed2006

Local and regional air pollution in Ireland during an intensive aerosol measurement campaign.

An intensive two month measurement campaign has been performed during a two year study of major component composition of urban PM10 and PM2.5 in Ireland (J. Yin, A. G. Allen, R. M. Harrison, S. G. Jennings, E. Wright, M. Fitzpatrick, T. Healy, E. Barry, D. Ceburnis and D. McCusker, Atmos. Res., 2005, 78(3-4), 149-165). Measurements included size-segregated mass, soluble ions, elemental carbon (EC) distributions, fine and coarse fraction organic carbon (OC) and major gases along with standard meteorological measurements. The study revealed that urban emissions in Ireland had mainly a local character and therefore were confined within a limited area of 20-30 km radius, without significantly affecting regional air quality. Gaseous measurements have shown that urban emissions in Ireland had clear, but fairly limited influence on the regional air quality due to favorable mixing conditions at higher wind speeds, in particular from the western sector. Size-segregated mass and chemical measurements revealed a clear demarcation size between accumulation and coarse modes at about 0.8 microm which was constant at all sites. Carbonaceous compounds at the urban site accounted for up to 90% of the particle mass in a size range of 0.066-0.61 microm. Nss SO4(2-) concentrations in PM2.5 were only slightly higher at the urban site compared to the rural or coastal sites, while NO3- and NH4+ concentrations were similar at the urban and coastal sites, but were a factor of 2 to 3 higher than at the rural site. OC was highly variable between the sites and revealed clear seasonal differences. Natural or biogenic OC component accounted for <10% in winter and up to 30% in summer of the PM2.5 OC at urban sites. A contribution of biogenic OC component to PM2.5 OC mass at rural site was dominant.

Aerosols↗
PubMed2001

Intrathoracic splenosis: superiority of technetium Tc 99m heat-damaged RBC imaging.

Intrathoracic splenosis is a rare diagnosis that is usually made following an invasive procedure. Although radiographic and CT findings are nonspecific, these findings combined with a history of splenic injury should suggest the possibility of this diagnosis. We present a patient with intrathoracic splenosis diagnosed on the basis of a technetium Tc 99m heat-damaged RBC scan following false-negative technetium Tc 99m sulfur colloid scan results.

Diaphragm↗
PubMed1999

Diagnostic accuracy of colposcopic photographs in child sexual abuse evaluations.

STUDY OBJECTIVE: To evaluate the utility of colposcopic photographs in child sexual abuse evaluations and to assess whether such photographs can be reliably used for peer review, second opinion, and court testimony. METHODS: A prospective review of colposcopic photographs at the Pediatric and Adolescent Gynecology Clinic in Louisville, Kentucky. Participants were 189 girls who were referred for evaluation for possible sexual abuse. Interventions used included gynecologic evaluation, colposcopic photographs, and review of photographs. The main outcome measure was the degree of agreement between the examining physician and the reviewers. RESULTS: The reviewers' accuracy for the entire set of 189 cases is uniformly high (93%-95%). Accuracy rates are significantly lower for pubertal girls (83%-90%) and for girls with signs of abuse (58%-88%). CONCLUSIONS: The diagnostic accuracy of the colposcopic photographs is sufficiently high to warrant continued use of medical photography for documentation and peer review. One should anticipate some disagreements between the examining physician and the reviewers, and contradictory opinions are more likely to occur with girls exhibiting physical signs of abuse and with pubertal girls.

Adolescent↗
PubMed1999

The impact of blood cultures on antibiotic therapy in pneumococcal pneumonia.

INTRODUCTION: The cost-effectiveness of blood cultures in community-acquired pneumonia (CAP) has been questioned. Although penicillin-resistant Streptococcus pneumoniae is an increasing problem, penicillin therapy, where appropriate, reduces cost and may reduce antibiotic resistance. Blood cultures, however, can only reduce cost if physicians are prepared to alter therapy based on the results. We reviewed our experience to determine how often physicians changed management based on blood culture results positive for S pneumoniae. METHODS: Retrospective chart review was performed of all CAP admissions between January 1996 and December 1998 with blood culture results positive for S pneumoniae. RESULTS: Seventy-four patients out of 1,805 patients admitted with CAP during this period had pneumococcemia. Penicillin resistance was identified in 15 cases (20.3%; high grade in 4 cases) with cephalosporin resistance in 4 of these cases (1 high grade). Fifty-one patients had initial empiric therapy with a third-generation cephalosporin, and 58 patients had empiric coverage of atypical organisms; no patient received empiric penicillin therapy. Blood culture results altered management in 31 patients (41.9%), but in only 2 cases was this due to antibiotic resistance. Fifty-one patients without penicillin allergy grew penicillin-sensitive pneumococci; only 11 patients (21.6%) were changed to penicillin therapy. Thirteen of 35 patients (37.1%) who were given an additional antibiotic for atypical coverage had this antibiotic ceased. CONCLUSION: Despite evidence of penicillin-sensitive pneumococcal CAP, physicians were reluctant to narrow antibiotic therapy, potentially adding to treatment cost and reducing the impact of blood culture results on management. The impact of penicillin resistance was reduced by the usual empiric choice of a third-generation cephalosporin. While positive blood culture results can clearly be useful in the management of patients with CAP, their cost-effectiveness needs to be assessed in prospective clinical trials.

Blood↗
PubMed1998

Ventilator-associated pneumonia in patients with adult respiratory distress syndrome: CT evaluation.

PURPOSE: To determine the diagnostic accuracy of computed tomography (CT) for pneumonia in patients with adult respiratory distress syndrome (ARDS). MATERIALS AND METHODS: CT scans were obtained within 1 week of bronchoscopic sampling in 31 patients receiving mechanical ventilation for ARDS for more than 48 hours. Of 11 patients with pneumonia, five developed symptoms less than 11 days after the onset of ARDS (early ARDS). CT scans were rated for pneumonia independently by four radiologists who were unaware of the clinical diagnosis. Diagnostic accuracy was defined by means of the area under the receiver operating characteristic curve, or A2. RESULTS: Diagnostic accuracy for pneumonia was fair (A2 = 0.69 +/- 0.04 [standard error]) owing to 70% true-negative ratings (vs 59% true-positive ratings). The generalizability coefficient was good (0.79). No single CT finding was significantly different for the presence of pneumonia. Nondependent opacities predominated in 10 (91%) of 11 patients with pneumonia and 12 (60%) of 20 without pneumonia. Nondependent opacities predominated in nine (56%) of 16 patients with early ARDS and 13 (87%) of 15 with late ARDS. CONCLUSION: CT has fair diagnostic accuracy for ventilator-associated pneumonia in patients with ARDS owing primarily to identification of patients without pneumonia. No single CT sign was significantly different for pneumonia, but dependent atelectasis was more common in patients with early ARDS without pneumonia.

Adolescent↗
PubMed1997

Pulmonary complications in children with hematologic malignancies: accuracy of diagnosis with chest radiography and CT.

PURPOSE: To determine the diagnostic accuracy of chest radiography and computed tomography (CT) in patients with complications during treatment for hematologic malignancies. MATERIALS AND METHODS: CT scans were obtained 1 week or less before bronchoscopic sampling or biopsy in 48 pediatric patients (age range, 8 months to 18 years at diagnosis) undergoing treatment for leukemia, lymphoma, or myeloproliferative disease. Radiographs were obtained less than 1 week before CT. Pulmonary complications comprised fungal (n = 11), viral (n = 4), and bacterial (n = 5) pneumonias; cryptogenic organizing pneumonia ([COP] n = 4); and pulmonary tumor (n = 4). Chest radiographs and CT scans were rated independently by three radiologists who were unaware of these diagnoses. RESULTS: Satisfactory diagnostic accuracy, defined by the area under the receiver operating characteristic (ROC) curve, was noted for fungal pneumonia (radiography, ROC area = 0.82; CT, ROC area = 0.78), COP (radiography, ROC area = 0.75; CT, ROC area = 0.75), and pulmonary tumor (radiography, ROC area = 0.73; CT, ROC area = 0.83). Generalizability was good for fungal pneumonia (radiography, generalizability coefficient [GC] = 0.84; CT, GC = 0.84) and COP (radiography, GC = 0.75; CT, GC = 0.99). There was no statistically significant difference in diagnostic accuracy between radiography and CT for any of the diagnoses. CONCLUSION: Radiography and CT have satisfactory accuracies for fungal pneumonia and COP. For these conditions, CT identified more true-positive cases than did radiography.

Adolescent↗
PubMed1995

Childhood lymphoma: diagnostic accuracy of chest radiography for severe pulmonary complications.

INTRODUCTION: We sought to determine whether chest radiography can be reliably used to distinguish persistent or relapsing pulmonary lymphoma from a variety of infectious and noninfectious pulmonary conditions that can occur in children receiving treatment for lymphoma. METHODS: We studied chest radiographs of 37 patients (30 with non-Hodgkin's lymphoma, and seven with Hodgkin's disease) who died of paediatric lymphoma or of treatment complications. Pulmonary findings at autopsy comprised lung tumour (n = 14), pleural tumour (n = 12), pneumonia (n = 22), adult respiratory distress syndrome (ARDS; n = 16), haemorrhage (n = 27), and infarction (n = 13). Using a 4-point scale and without knowledge of autopsy findings, three radiologists independently rated antemortem radiographs for the presence of pulmonary tumour, pleural tumour, pneumonia in general, pneumonia caused by viral, bacterial, fungal, and protozoan pathogens, ARDS, pulmonary haemorrhage, and pulmonary infarction. Diagnostic accuracy was defined by the area under the receiver-operating-characteristic curve (AZ). RESULTS: Diagnostic accuracy was good for pulmonary tumour (AZ, 0.71 +/- 0.6), protozoan pneumonia (AZ, 0.77 +/- 0.06), and ARDS (AZ, 0.86 +/- 0.07) but poor for all other conditions. The absence of both pleural effusions and mediastinal/right hilar lymphadenopathy was significantly associated (P < or = 0.04) with the absence of lung tumour. DISCUSSION: The pulmonary processes in these patients can all demonstrate diffuse airspace opacification, and many patients had multiple lung abnormalities at autopsy. The radiologist-readers were unable to identify which pulmonary conditions were responsible for radiographic findings in most patients. The readers were able to identify patients who did not have pulmonary lymphoma. If pulmonary involvement with lymphoma is unlikely, bronchoscopy with bronchoalveolar lavage may be sufficient to establish a diagnosis. When pulmonary lymphoma is a clinical consideration, open lung biopsy is usually required for diagnosis.

Adolescent↗
PubMed1995

Ventilator-associated Pseudomonas aeruginosa pneumonia: radiographic findings.

PURPOSE: To characterize the radiographic features of ventilator-associated Pseudomonas aeruginosa pneumonia (PAP). MATERIALS AND METHODS: In 56 patients (40 men and 16 women), PAP was documented with fiberoptic bronchoscopy. All patients underwent mechanical ventilation for at least 48 hours before diagnosis. The findings on chest radiographs were recorded. In eight patients in whom computed tomography (CT) was performed, results were compared with radiographic findings. RESULTS: Twenty-six patients with adult respiratory distress syndrome (ARDS) had diffuse bilateral confluent opacities; 30 patients without ARDS had multifocal opacities. In 13 patients, cavities were detected at chest radiography, CT, or both. Seven of 29 patients with pleural abnormalities had empyema. CT provided important additional information (presence of cavities or effusions) in four cases. CONCLUSION: Findings on chest radiographs are nonspecific for PAP. The frequencies of cavities and empyema are surprisingly low, perhaps owing to prompt diagnosis and therapy.

Bronchoscopy↗
PubMed1994

Chest radiographic features of thoracic metastatic disease in adolescents with colon cancer.

This study describes chest radiographic features of thoracic metastatic disease (TMD) in patients referred for colon cancer to a pediatric oncology hospital. The study group was comprised of 9 patients (7 males, 2 females, age 13-19 years) with serial chest radiographs demonstrating TMD from colon cancer. All patients had a chest radiograph performed within the 2 months prior to death. The median interval from diagnosis of colon cancer to appearance of radiographic TMD was 3 months. Four of nine patients had TMD at presentation, eight of nine patients within 2 years of diagnosis. All abnormalities progressed on serial radiographs. The median interval from appearance of radiographic abnormalities to death was 2 months. Radiographic findings included pleural effusions (n = 6), lymphadenopathy (n = 5), lymphangitic carcinomatosis (n = 4), solitary pulmonary nodule (n = 2), and lobar atelectasis (n = 1). Five patients with pleural effusions initially had right-sided effusions. Radiographic TMD in adolescents with colon cancer usually occurs within 2 years of diagnosis. Once TMD manifests, the prognosis is dismal. Findings include pleural effusions, lymphadenopathy, lymphangitic carcinomatosis, solitary pulmonary nodules, and lobar atelectasis. We suggest that metastatic colon carcinoma should be included in the differential diagnosis for lymphangitic spread of tumor in adolescents.

Adenocarcinoma↗
PubMed1994

Childhood leukemia: diagnostic accuracy of bedside chest radiography for severe pulmonary complications.

PURPOSE: To determine the diagnostic accuracy of bedside chest radiography in patients who develop severe pulmonary complications while undergoing therapy for leukemia. MATERIALS AND METHODS: The authors studied 45 patients, aged 21 years and younger, who died of leukemia or of treatment complications and for whom autopsy findings were available. Pulmonary findings at autopsy comprised pneumonia (n = 25), adult respiratory distress syndrome (ARDS) (n = 16), hemorrhage (n = 38), infarction (n = 18), and leukemic cellular infiltration (n = 11). Four radiologists who were unaware of the autopsy diagnoses independently rated antemortem bedside chest radiographs. RESULTS: Diagnostic accuracy for each disease was as follows: ARDS, 0.81 +/- .03 (standard error); all pneumonias, 0.56 +/- .04; hemorrhage, 0.47 +/- .07; infarction, 0.50 +/- .12; and pulmonary leukemic cellular infiltration, 0.38 +/- .12. CONCLUSION: The specific radiographic appearance of ARDS permits excellent diagnostic accuracy.

Acute Disease↗
PubMed1993

Pneumonia and ARDS in patients receiving mechanical ventilation: diagnostic accuracy of chest radiography.

This study was done to evaluate the diagnostic accuracy of bedside chest radiography for pneumonia, adult respiratory distress syndrome (ARDS), or both in patients receiving mechanical ventilation. The series consisted of 40 patients; diagnostic accuracy was defined as the area under the receiver operating characteristic curve. Overall diagnostic accuracy for ARDS was 0.84. Overall diagnostic accuracy for pneumonia was 0.52. Review of previous radiographs and knowledge of clinical data did not enhance diagnostic accuracy for ARDS or pneumonia. Diagnostic accuracy for pneumonia was minimally reduced when ARDS was present. There was an increase in false-negative results because the diffuse areas of increased opacity in ARDS obscured the radiographic features of pneumonia. The authors conclude that chest radiography is of limited value for the diagnosis of pneumonia in patients receiving mechanical ventilation. The high false-negative and false-positive ratings for pneumonia resulted in a low diagnostic accuracy. The high diagnostic accuracy for ARDS was primarily due to the well-defined radiographic appearance of ARDS and few false-positive ratings.

Adolescent↗
PubMed1993

Primitive neuroectodermal tumors of the chest wall (Askin tumors): CT and MR findings.

OBJECTIVE: The objective of this study was to describe the CT and MR appearances of primitive neuroectodermal tumors of the thoracopulmonary region (Askin tumor), which typically manifest as large tumors involving the chest wall and pleura. This rare malignant neoplasm, seen predominantly in children and young adults, originates in soft tissues of the chest wall, occasionally in bone, or, rarely, in the periphery of the lung. SUBJECTS AND METHODS: The study group included two boys and six girls, 7-18 years old, with thoracic primitive neuroectodermal tumors who had had CT and MR studies at presentation. In seven of these patients, the preoperative imaging interpretation was compared with surgical observations. RESULTS: Seven tumors were large. Unilateral chest wall involvement was seen in all eight patients, pleural involvement in seven, and rib destruction in five. All tumors were heterogeneous on CT scans and T2-weighted MR images, and seven were heterogenous on T1-weighted MR images. The smallest tumor was homogeneous on T1-weighted MR images. Seven tumors had a signal intensity greater than that of skeletal muscle on T1-weighted MR images, and seven showed hemorrhage or necrosis. Invasion of muscle in the chest wall was noted on MR images in seven patients and on CT scans in four patients. CT scans and MR images showed extension of tumor into adjacent lung in four patients but were indeterminate in three patients. One patient had no extension of tumor into adjacent lung. Pulmonary metastases were noted on MR images in one patient and on CT scans in three patients. CT and MR studies correctly showed pleural (n = 6), rib (n = 4), pericardial (n = 1), diaphragmatic (n = 1), and vertebral/spinal cord (n = 1) involvement, confirmed during surgery. CT and MR scans of five patients imaged before surgery were indeterminate for adjacent lung invasion. CONCLUSION: The described radiologic features of Askin tumors may be useful in deciding when to include this entity in the differential diagnosis. Areas of hemorrhage and necrosis in the large tumors are responsible for their heterogeneous appearance on CT scans and MR images. CT scans and MR images are complementary for determining the extent of disease. MR imaging is informative for determining invasion of chest wall muscle, whereas CT scanning is preferred for detecting small pulmonary metastases. Neither technique is adequate for predicting invasion of adjacent lung.

Adolescent↗
PubMedDate not supplied

Weight reduction in the prevention and treatment of hypertension: a review of representative clinical trials.

Elevated blood pressure is a risk factor for cardiovascular disease, and weight reduction is currently advocated as a nonpharmacologic approach for the management of hypertension. Results of clinical trials indicate weight reduction is effective in preventing and treating hypertension. Knowledge of the results of clinical trials is extremely important for health educators since: 1) these findings provide a scientific basis for educating other health professionals about the beneficial effects of dietary approaches to the management of hypertension; 2) discussion of these results with patients may provide a means for altering patients' expectations and achieving improved treatment compliance; and 3) the processes by which clinical trials have achieved their dietary goals can provide health educators with extensive clinical experience upon which to draw in working with nonstudy patients. The content and general results of clinical trial programs are reviewed as well as features associated with health promotion in clinical trial and behavioral weight loss research.

Clinical Trials as Topic↗