Aortopulmonary fistula in an infected Dacron graft for coarctation of the aorta: an uncommon cause of hemoptysis

Hemoptysis secondary to an aortobronchial fistula is rare and uniformly fatal when left untreated. The authors describe a case of massive hemoptysis caused by an aortopulmonary fistula in an infected Dacron graft used successfully to repair a coarctation of the aorta.     

Respiratory activity of the rat posterior cricoarytenoid muscle

An anatomic and electrophysiological study of the rat posterior cricoarytenoid (PCA) muscle is described. The intramuscular nerve distribution of the PCA branch of the recurrent laryngeal nerve was demonstrated by a modified Sihler's stain. The nerve to the PCA was found to terminate in superior and inferior branches with a distribution that appeared to be confined to the PCA muscle. Electromyography (EMG) recordings of PCA muscle activity in anesthetized rats were obtained under stereotaxic control together with measurement of phrenic nerve discharge. A total of 151 recordings were made in 7 PCA muscles from 4 rats. Phasic inspiratory activity with a waveform similar to that of phrenic nerve discharge was found in 134 recordings, while a biphasic pattern with both inspiratory and post-inspiratory peaks was recorded from random sites within the PCA muscle on 17 occasions. The PCA EMG activity commenced 24.6 +/- 2.2 milliseconds (p < .0001) before phrenic nerve discharge. The results are in accord with findings of earlier studies that show that PCA muscle activity commences prior to inspiratory airflow and diaphragmatic muscle activity. The data suggest that PCA and diaphragm motoneurons share common or similar medullary pre-motoneurons. The earlier onset of PCA muscle activity may indicate a role for medullary pre-inspiratory neurons in initiating PCA activity.     

High affinity presentation of an autoantigenic peptide in type I diabetes by an HLA class II protein encoded in a haplotype protecting from disease

Tissue composition and the distribution of body mass are described for four genera of East African Bovidae (Madoqua, Gazella, Damaliscus, Hippotragus) with supporting data from four others (Neotragus, Oryx, Tragelaphus, Connochaetes). These species are high in muscle mass, an adaptation convergent with other high-speed terrestrial cursors, bounders, and saltators. The segments below the elbow/cubitus and knee/stifle/genu joints in small bovids are both lighter in percent of total body mass (8.6% TBM) and less heavily muscled (10-15% of total limb musculature) than those segments in macaques (13.6% TBM, 20-25% of the limb musculature). Bovid species differ from one another in the regional distribution of muscle mass. Madoqua kirkii (4-5 kg) concentrates muscle in the lumbar extensors and hindlimbs; large species such as Damaliscus doreas (50-60 kg) and Hippotragus niger (160-220 kg) distribute it more evenly between the lumbar and cervical regions and between the hindlimbs and forelimbs. Gazella dorcas (10-20 kg) is quantitatively intermediate in those characteristics. The redistribution of muscle mass with increasing size correlates with the loss of axial bending of the vertebral column: in small, hindlimb dominant, 'dorsomobile' species such as Madoqua sagittal mobility increases stride length through 'extended' suspension; in large 'dorsostable' species such as Damaliscus and Hippotragus the vertebral column resists bending, consequently abbreviating or omitting this non-contact phase of the gait cycle. Locomotor adaptation as it is reflected in size, shape, and musculoskeletal structure is the key to habitat choice, dietary specialization, social structure, and male agonistic behavior and, therefore, central to the fabric of behavioral ecology.     

Molecular characterization and role in T cell activation of staphylococcal enterotoxin A binding to the HLA-DR alpha-chain

Superantigens bind to MHC class II-positive cells and stimulate T lymphocytes expressing specific V beta regions of the TCR. Two distinct regions of staphylococcal enterotoxin A superantigen (SEA) have been shown to affect the binding to MHC class II molecules. Results presented here demonstrate for the first time that the SEA-DR interaction can be affected by mutations on the class II alpha-chain. Furthermore, we have precisely mapped the interaction of the SEA N-terminal domain with the alpha1 domain of HLA-DR. Scatchard analysis using DAP cells transfected with mutant class II molecules showed a role for residue DR alpha K39 in the binding of SEA. Also, complementation experiments using mutant SEA molecules revealed an interaction between SEA residue F47 and position alphaQ18 on an outer loop of HLA-DR. These interactions between SEAF47 and the DR alpha-chain are critical, as they allow the recognition by an otherwise nonreactive V beta1+ T cell hybridoma and induction of tyrosine phosphorylation through the TCR.     

Computerized determination of proliferating cell nuclear antigen expression in meningiomas. A comparison with non-automated method

Proliferating cell nuclear antigen (PCNA) expression has been proven to be a significant marker of cell proliferation in meningiomas, which correlates with growth rate and, as shown by several authors, possibly provides prognostic information concerning biologic behavior. However, the current method for determining PCNA labeling index (LI) is tedious and time consuming like all the nonautomated methods for evaluating cell kinetics, presenting high interobserver and interlaboratory variability and low reproducibility. In the present study, we introduce a semi-automated computer-assisted image analysis method for determining PCNA LI in 38 meningiomas, in parallel with the current nonautomated method. Image analysis technique permits unbiased cell counting, standardizes the degree of staining intensity and provides instant results. By calculating coefficient of variability, the method proved to be highly reproducible. The correlation between the results provided by the nonautomated and the semiautomated image analysis method showed a high agreement between them, with a correlation coefficient, r, of 0.82. In conclusion, we consider that image analysis contributes to the accuracy, reproducibility, and practicality of PCNA LI determination so that along with other useful parameters this significant marker may serve to predict the clinical behavior in meningiomas.     

Transfusion requirements are correlated with the degree of proteolysis of von Willebrand factor during orthotopic liver transplantation

During orthotopic liver transplantation (OLT) excessive bleeding is the main cause of death and graft failure. The acute bleeding tendency that accompanies OLT, particularly during the anhepatic period and after reperfusion of the graft, is due to the depletion or functional abnormalities of several hemostasis components caused by the enhanced activity of enzymes such as plasmin, trypsin and leukocyte proteases. We surmised that enhanced proteolysis might also cause abnormalities of von Willebrand factor (vWF), and that these abnormalities are implicated in the bleeding tendency that develops during OLT. Therefore, the pattern of vWF proteolysis was studied with 16 patients with chronic liver disease, in serial blood samples obtained before OLT, during the anhepatic stage, after graft reperfusion and at the end of the surgical procedure. vWF became markedly degraded during the anhepatic and reperfusion stages, as shown by the partial loss of high molecular weight multimers, the relative decrease of the intact 225 kD subunit and the increase of the native proteolytic fragments of 176 and 140 kD. Novel proteolytic fragments also became detectable. Using monoclonal antibody epitope mapping, it could be demonstrated that some of the proteolytic fragments corresponded in apparent molecular mass to those produced in vitro by incubating purified vWF with plasmin or elastase, but other fragments could not be attributed to these proteases. During the anhepatic and reperfusion stages there was a significant correlation between the degree of vWF degradation and the total amount of blood components transfused to replace blood losses. To evaluate whether or not vWF degradation could be controlled by the administration of a broad-spectrum protease inhibitor such as aprotinin, 5 patients were given a bolus dose of 500,000 U before surgery followed by 100,000 U/h during surgery, 5 were given a 2,000,000 U bolus followed by 500,000 U/h, and no aprotinin was given to the remaining 6 patients. There were no differences in the patterns or degrees of vWF degradation between patients treated with aprotinin or not. In conclusion, there is a marked degradation of a key hemostasis protein during OLT. These alterations may be of clinical significance, because they are correlated with the transfusion requirements.     

Appendiceal and peri-appendiceal air at CT: prevalence, appearance and clinical significance

AIM: Appendiceal air has been reported as both a sign of appendicitis and of a normal appendix both at plain radiography and computed tomography (CT). It is the aim of this investigation to determine the prevalence, range of appearances, and significance of appendiceal and peri-appendiceal air at CT. PATIENTS AND METHODS: Appendiceal CT scans of 100 patients with proven appendicitis and 100 patients with a normal appendix were reviewed for the presence of appendiceal and peri-appendiceal air. All cases were correlated with surgical and pathological findings or clinical follow-up. RESULTS: In 100 CT cases of appendicitis, appendiceal and/or peri-appendiceal air was present in one or more forms in 31% of cases. When present, it appeared as intraluminal air bubbles (38.7%) or air-fluid levels (22.6%), appendolith air (41.9%), intramural air (16.1%), peri-appendiceal air bubbles (12.9%), or extraluminal air-fluid level(s) (29.0%). Intramural and extraluminal air correlated with perforation in 60% and 100%, respectively. In 100 CT cases of a normal appendix, air was present in 57%. It was always intraluminal and appeared as small bubbles of air (52.6%), a tubular-shaped air collection (43.9%), or as an air-fluid level (3.5%). The appendiceal lumen was either airless (43%), or minimally (32%), moderately (18%), or completely filled with air (7%). CONCLUSION: Air is a common finding at appendiceal CT in both the normal and inflamed appendix. Intraluminal air is seen in both appendicitis and normal appendices, and cannot be presumed to indicate a patent lumen and thus a normal appendix. Appendolith, intramural and peri-appendiceal air appear diagnostic of appendicitis.     

Altered proton extrusion in cells adapted to growth at low extracellular pH

Coronary vasodilator and hemodynamic profiles of JTV-506, a newly synthesized 2,2-bis-methoxymethyl benzopyran-derivative potassium channel opener, were evaluated in conscious dogs. JTV-506 (2.5-10 microg/kg, i.v.) elicited dose-dependent increases in coronary blood flow (CBF) and heart rate (HR) but only slight changes in mean blood pressure (MBP). Other vasodilators such as levcromakalim, nicorandil, diltiazem, and nitroglycerin, when administered intravenously, elicited increases in CBF and HR and a decrease in MBP. When dosed orally JTV-506 (0.01-0.1 mg/kg), levcromakalim (0.01-0.1 mg/kg), nicorandil (1-10 mg/kg), and nifedipine (3-30 mg/kg) also elicited increases in CBF and HR and a decrease in MBP. JTV-506 caused a marked increase in CBF with slight changes in HR and MBP. In contrast to JTV-506, however, the changes caused by levcromakalim, nicorandil, and nifedipine were accompanied by a marked increase in HR and a marked decrease in MBP. These results suggest that the action of JTV-506 on hemodynamics is different from that of other vasodilators, including reference potassium channel openers, and that the profile of cardiovascular action of JTV-506 may be useful in the treatment of angina pectoris.     

Reflex sympathetic function in cortisol-induced hypertension in humans

Nine healthy male subjects underwent measurement of reflex sympathetic function, pressor responsiveness and baroreflex sensitivity to phenylephrine (PE) and glyceryltrinitrate (GTN) before (C1) and following six days of treatment (E6) with cortisol (F), 200 mg/day. Seven subjects had washout studies (W) performed at least two weeks following the end of treatment. The BP responses to head tilt, isometric exercise and mental arithmetic were unaltered by F, however, there was a significant diminution of the diastolic BP response to cold pressor stimulus (delta DBP: 19 +/- 3 vs 25 +/- 5 vs 27 +/- 5 mmHg; E6 vs C1 vs W, p < 0.05 C1 vs E6 and W). Baroreflex sensitivity to PE was increased (28 +/- 3 vs 19 +/- 2 ms/mmHg, E6 vs C1, p = 0.03). These data demonstrate that increased BP during F treatment is not attributable to increased SNS activity, and suggest that SNS activity may be decreased by F.     

Thoracic epidural anesthesia as the last option for treating angina in a patient before coronary artery bypass surgery

Robertsonian translocations, although relatively common as a constitutional genetic aberration, are rarely encountered in leukaemia. We report a case of acute myeloid leukaemia which showed an acquired Robertsonian translocation in the form of der(14;21) by cytogenetic analysis of leukaemic cells. This was confirmed by the PHA-stimulated culture of peripheral blood lymphocytes. A review of the literature identifies only eight reported cases of acquired Robertsonian translocations in leukaemia. In the majority of cases the Robertsonian translocation occurs as a secondary change in a complex abnormal clone, whereas in two out of nine patients reported, including ours, it is found as a sole karyotypic abnormality.