Integrin stimulation regulates polymorphonuclear leukocytes inflammatory cytokine expression.

OBJECTIVE: The purpose of these studies is to investigate the role of integrin binding on the regulation of polymorphonuclear leukocyte (PMN) cytokine receptor expression. SUMMARY BACKGROUND DATA: Current knowledge in this area revolves around the ability of beta 2 integrins to mediate PMN adherence and chemotaxis. The role of alpha 1-6/beta 1 integrins in regulating cytokine receptor expression has not been probed. METHODS: Purified human PMN were adhered on plastic, fibronectin, or laminin-coated surfaces followed by the addition of iodine 125 (125I) monoclonal antibodies (mAbs) directed against tumor necrosis factor-alpha R (TNF-alpha R) p60, p80, or interleukin-1 beta R (IL-1 beta R) types I, II. Receptor expression was calculated based on the counts per minute (cpm) bound. The role of individual beta 1 integrins was assessed using mAbs directed against the alpha 1-6 subunit of the beta 1 complex, and integrin cross-linkage was achieved using secondary goat antimouse F(ab')2 antibodies. Polymorphonuclear leukocytes were pretreated with herbimycin A to determine the role of protein tyrosine kinase in mediating the effect of the beta 1 integrins. RESULTS: Adherence of PMN to Ln decreased IL-1 beta types I, II receptor expression, whereas adherence to Fn increased TNF-alpha R p60 and p80 expression. Anti-VLA-5 (CD49e) but not anti-VLA-1 through VLA-4 and VLA-6, blocked the effect of Fn on TNF-alpha receptors, whereas anti-VLA-6 but not anti-VLA-1 through VLA-5 blocked the effect of Ln on IL-1 beta receptors. Modulation of IL-1 beta and TNF-alpha receptors by VLA-5 and VLA-6 required protein tyrosine kinase activation as herbimycin A (10 micrograms/mL) blocked the affect of Fn and Ln. Changes in PMN cytokine receptor expression led to parallel changes in functional activity as assessed by the binding of 125I IL-1 beta and TNF-alpha. CONCLUSIONS: Integrin stimulation regulates the cell surface expression of PMN cytokine receptors. Ligation of CD49e upregulates TNF-alpha receptor expression, whereas binding of CD49f downregulates IL-1 beta receptor expression. Both processes are protein tyrosine kinase dependent. Changes in PMN cytokine receptor expression led to corresponding changes in functional activity. These results provide the first demonstration that chemotaxis of PMN into the interstitium provides a mechanism for ongoing participation in the local inflammatory response and is regulated by matrix protein integrin receptors.     

Career advancement of nurse executives: planned or accidental?

This exploratory study has examined the effect of selected characteristics on the career advancement patterns of nurse executives in service and educational settings. The findings are not consistently in agreement with those of other researchers. For example, Hall et al. found that nearly two-thirds of nursing deans had planned their careers to attain that position. In this study, however, eighty-three percent of the respondents indicated that they had not planned their career advancement, but had simply taken opportunities that had come their way. The influence of others was important in the career advancement of these administrators. Many individuals, including faculty and nursing service colleagues, nursing directors, deans, and non-nursing administrators supported the respondents' personal and professional development through role modeling, teaching skills, and encouragement. Deliberate career planning and education in administration were, for the most part, lacking. Although the sample is too small to generate general conclusions about the universe of nurse executives, this does suggest that it is not uncommon for deans and service administrators to learn necessary skills on the job.     

Shoulder instability: impact of glenohumeral arthrotomography on treatment

We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder.     

Recurrent aorto-duodenal fistula: a final solution?

This paper describes a case of recurrent aorto-duodenal fistula treated successfully by re-sitting the duodenum in an ante-colic position. Secondary aorto-duodenal fistula affects less than 1% of patients who have received a prosthetic abdominal aortic graft. However following correction of such a fistula the incidence of recurrent fistulation or aortic stump blow-out is reported as high as 47%. we describe an alternative approach to management of this difficult problem.     

Rupture of the posterior tibial tendon: CT and surgical findings

Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.     

Excessive fibrinolysis in amyloidosis associated with elevated plasma single-chain urokinase.

Severe bleeding resulting from excessive fibrinolysis has been observed in patients with primary amyloidosis. The authors studied a patient with this hemostatic disorder before and during therapy with epsilon-aminocaproic acid. Excessive fibrinolysis was associated with depressed plasma concentrations of coagulation Factors XII, XI, high-molecular-weight kininogen, and Factors VIII and V; and plasminogen and alpha-2-plasmin inhibitor. These deficiencies were corrected with treatment. The functional and antigenic concentrations of tissue plasminogen activator and plasminogen activator inhibitor in the patient's plasma were normal. Urokinase-type activator activity and antigen were three to five times elevated in the patient's plasma. Results of immunoprecipitation showed that single-chain urokinase-type activator was the primary urokinase-type activator species in the patient's plasma. Excessive fibrinolysis in patients with amyloidosis results from increased plasma single-chain urokinase-type activator activity.