Contrasting roles for RANTES and macrophage inflammatory protein-1 alpha (MIP-1 alpha) in a murine model of allergic peritonitis.

Cell accumulation and CC chemokine production were assessed in the peritoneal cavity of ovalbumin (OVA)-sensitized mice following antigen challenge. Intraperitoneal challenge with OVA induced a significant eosinophil influx from 6 h post-challenge with increased numbers persisting at 24 h. At 6 h there was also a marked presence of neutrophils. Messenger RNA expression and protein levels for the chemokines RANTES and MIP-1 alpha were measured in the cell pellets and supernatants, respectively, from peritoneal washes following OVA challenge. RANTES mRNA was detected from 2 h to 4 h following OVA injection, whereas mRNA for MIP-1 alpha was only detectable at 4 h. RANTES protein was first detected from 4 h after OVA injection and by 24 h the protein levels had increased further. Basal levels of MIP-1 alpha were detected in peritoneal washes. These levels peaked at 2 h after OVA challenge and rapidly declined to basal levels by 6 h. A functional role for the chemokines was assessed using neutralizing polyclonal antibodies. Co-injection of OVA with anti-RANTES antibodies resulted in a significant inhibition of eosinophil infiltration into the cavity at 6 h and 24 h (63% and 52% inhibition, respectively) without significantly influencing the number of neutrophils present. In contrast, injection of anti-MIP-1 alpha antibodies only inhibited neutrophil migration at the 6 h time point by 44% without significantly affecting the accumulation of eosinophils. These results demonstrate an important role for RANTES in mediating eosinophil influx in allergic inflammation and a contrasting role for MIP-1 alpha in mediating neutrophil recruitment.     

The relationship between pulmonary artery pressure and pulmonary artery diameter in pulmonary hypertension

The pulmonary arteries dilate in response to many factors, principally increased pressure and flow. In patients who have pulmonary arterial hypertension but no increase in flow, we have compared main pulmonary artery size at computed tomography with pulmonary haemodynamic data obtained during right heart catheterisation. In patients with primary pulmonary hypertension and chronic thromboembolic pulmonary hypertension, dilatation correlated with raised pulmonary vascular resistance and reduced cardiac output but not with mean arterial pressure. In patients with chronic lung disease no correlations were shown though a trend between raised pressure and size was observed. We speculate that pulmonary artery compliance is an important factor which determines the degree of dilatation in response to raised pressure. Estimations of pressure cannot be made from measurements of pulmonary artery size without knowledge of the underlying lung disease.     

How useful is computed tomography in the diagnosis and assessment of bronchiectasis?

A study was performed to determine the value of computed tomography (CT) in the diagnosis and assessment of cylindrical and mild varicose bronchiectasis. Fifteen patients, in whom bronchography had shown such bronchiectasis in 34 of 73 lobes that could be assessed, were examined by CT. A control group of 12 subjects in whom there was no clinical or plain radiographic suspicion of bronchiectasis was also studied. Computed tomography (CT) was considered to show bronchiectasis in 28 lobes, 27 of which were bronchiectatic as shown by bronchography. Of 45 lobes where CT was not thought to show bronchiectasis, bronchography demonstrated 38 normal and seven bronchiectatic lobes. All lobes in the control group were interpreted as normal. Using bronchography as the definitive investigation for cylindrical or mild varicose bronchiectasis, CT has a sensitivity of 79% and a specificity of 99% in the diagnosis of the disease. The high specificity indicates that a diagnosis of cylindrical or mild varicose bronchiectasis by CT is reliable but CT is too insensitive to be used as a screening test.     

Thoracic outlet syndrome: evaluation with CT

Diagnosis of the thoracic outlet syndrome is often difficult, particularly in patients without osseous abnormalities on plain radiographs. The radiographic and computed tomographic (CT) findings were reviewed from 27 patients with thoracic outlet syndrome and 21 normal subjects. The plain radiographs and CT scans were assessed by two independent observers without awareness of the clinical history. Fifteen patients with thoracic outlet syndrome had osseous abnormalities (anomalous cervical ribs; abnormally long, drooping C-7 transverse processes) identifiable on plain radiographs. CT did not provide further diagnostic information in the patients with abnormal radiographs. Eight of 12 patients (66%) with normal plain radiographs had abnormal findings on CT scans, consisting of impingement of the C-7 transverse process on the scalene triangle or anteromedial aspect of the middle scalene muscle. Only two of 21 control patients (9.5%) displayed this CT abnormality (P less than .01). CT may be useful in patients with symptoms suggestive of thoracic outlet syndrome and no osseous abnormalities on plain radiographs.     

MRI of the athletic knee. Findings in asymptomatic professional basketball and collegiate football players

For the dedicated athlete in whom minor injuries are frequent and major injuries relatively common, a noninvasive knee assessment could either obviate the need for arthroscopy or focus its direction. The opportunity to study asymptomatic athletes was not feasible before the advent of magnetic resonance imaging (MRI). In this preliminary work, we examined 40 knees in 20 asymptomatic volunteer athletes, including five professional basketball players and 15 collegiate football players. Images were obtained at 0.5 T or 1.5 T. Spin echo sequences were used to obtain 5.0 mm thick coronal and sagittal sections. Fifty percent of asymptomatic athletes (10/20) had significant baseline MRI abnormalities that could have adversely affected scan interpretation in the context of an acute injury. Half of these athletes with MRI abnormalities, or 25% of the total (5/20), had no previous surgery and were unaware of significant injury.     

Aspergillus infection of the respiratory tract after lung transplantation: chest radiographic and CT findings

The objective of our study was to assess radiographic and CT findings in lung transplant patients with evidence of Aspergillus colonization or infection of the airways and correlate the findings with clinical, laboratory, bronchoalveolar lavage, biopsy and autopsy findings. The records of 189 patients who had undergone lung transplantation were retrospectively reviewed for evidence of Aspergillus colonization or infection of the airways. Aspergillus was demonstrated by culture or microscopy of sputum or bronchoalveolar lavage fluid or histologically from lung biopsies or postmortem studies in 44 patients (23 %). Notes and radiographs were available for analysis in 30 patients. In 12 of the 30 patients (40 %) chest radiographs remained normal. In 11 of 18 patients with abnormal radiographs pulmonary abnormalities were attributed to invasive pulmonary aspergillosis (IPA) in the absence of other causes for pulmonary abnormalities (8 patients) or because of histological demonstration of IPA (3 patients). In these 11 patients initial radiographic abnormalities were focal areas of patchy consolidation (8 patients), ill-defined pulmonary nodules (2 patients) or a combination of both (1 patient). In some of the lesions cavitation was demonstrated subsequently. At CT a “halo” of decreased density was demonstrated in some of the nodules and lesion morphology and location were shown more precisely. Demonstration of Aspergillus from the respiratory tract after lung transplantation does not necessarily reflect IPA but may represent colonization of the airways or semi-invasive aspergillosis. The findings in patients with IPA did not differ from those described in the literature in other immunocompromised patients, suggesting that surgical disruption of lymphatic drainage and nervous supply or effects of preservation and transport of the transplant lung do not affect the radiographic appearances. Received 24 March 1997; Revision received 27 June 1997; Accepted 20 August 1997     

Radiological evaluation of the ascending aorta following repair of type A dissection

A patient with persistent chronic dissection proximal to an aortic interposition graft for repair of a type A dissection prompted us to review the computed tomographic (CT) findings in 14 other such patients 5–47 months after surgery. No other case of proximal aortic dissection was identified although dilatation of the aortic root proximal to the graft was present in 8 patients (57%). Persistent dissection distal to the graft in 11 patients (79%) was in keeping with that reported by other workers. Chronic dissection proximal to the surgical repair of a dissection seems a rare although important complication     

Histological characterization of a delayed wound healing model in pig

Chronic wounds, such as venous ulcers and pressure ulcers, frequently remain unresponsive to currently available treatments. Several animal models of wound healing have been published, including models of impaired healing developed to mimic the clinical condition of chronic wounds better. We used a delayed wound healing model in the pig that uses irradiation of the skin prior to creation of the surgical wounds and characterized it histologically. Radiation was used on one side of the back prior to making four full-thickness wounds on each side. Clinical observations were performed to record granulation tissue, reepithelialization, and wound area as a function of time. Histology data were obtained at 1, 2, 3, and 4 weeks, and slides were stained with hematoxylin and eosin for general observations. Immunohistochemistry was performed using laminin as a marker for blood vessels, and the number, size, and circularity of blood vessels found in the granulation tissue were measured. Our results show that this model causes a delay in wound healing that is mostly apparent between days 7 and 15. Granulation tissue took more time to form and fill the wounds on the irradiated side, and blood vessels were slower to develop. Blood vessels were larger and more irregular in shape on the irradiated side than on the control side. After 2 weeks, healing resumed, indicating that the induced damage was not irreversible. These results suggest that this model can be used to test the effects of therapeutic approaches intended to treat chronic wounds.