Postsplenectomy Capnocytophaga canimorsus sepsis presenting as an acute abdomen.

Patients with intra-abdominal processes that require prompt surgical intervention, including appendicitis, perforated viscus, ischemic bowel, volvulus, and bowel obstruction, often present with signs and symptoms of an acute abdomen. Several medical problems can mimic an acute abdomen. Overwhelming postsplenectomy infection is a life-threatening condition that can present with acute abdominal symptoms. The incidence of overwhelming postsplenectomy infection ranges from 1% to 25%, and is caused by Streptococcus pneumoniae in 50% of cases. Capnocytophaga canimorsus, a bacteria commonly found in dog saliva, accounts for less than 1% of cases. Overwhelming postsplenectomy infection has a rapidly deteriorating course that progresses to respiratory and renal failure, cardiovascular collapse, and death. The mortality associated with overwhelming postsplenectomy infection is 60% to 80%. Early diagnosis and institution of appropriate antibiotic therapy and supportive care is essential to improve patient outcome. A previously healthy woman who had undergone splenectomy secondary to trauma 11 years earlier presented with symptoms of an acute abdomen. A diagnosis of overwhelming postsplenectomy infection due to C canimorsus was made based on her peripheral blood smear and blood culture findings. Early aggressive care and antibiotic treatment resulted in a successful outcome for this patient with no long-term morbidity. This patient's clinical course demonstrates the importance of early diagnosis and treatment of overwhelming postsplenectomy infection.

The differential effect of contrast agents on endothelial cell and smooth muscle cell growth in vitro.

PURPOSE: This study was designed to evaluate the effects of ionic and nonionic contrast agents on endothelial cell (EC) and smooth muscle cell (SMC) proliferation, and to determine the role of osmolality as the etiology of these effects. METHODS: Cultured bovine aorta EC and SMC were exposed to ionic (iothalamate meglumine) or nonionic (ioversol or iopamidol) contrast, or varying osmolar solutions of mannitol, for periods of 1, 3, 5, 10, or 20 minutes. Cells were then incubated in growth media at 37 degrees C and proliferation and structure were assessed 1, 3, 5, and 7 days later. RESULTS: Both EC and SMC showed decreased proliferation after brief exposure to both ionic and nonionic contrast. Proliferation was markedly decreased at 24 hours after exposure, and began to recover by day 3 after exposure. EC showed a significant decrease up to 7 days after exposure to ionic contrast (p < 0.03), whereas SMC showed a significant decrease up to 7 days after exposure to nonionic contrast (p < 0.001). The decrease in proliferation was directly dependent on the length of exposure to the contrast and the concentration of the contrast. EC proliferation decreased in proportion to increasing osmolality of the test solution (p < 0.05). SMC proliferation did not show a decrease proportional to osmolality. No change was observed in cell viability as assessed by LDH activity studies. After contrast exposure, bare areas with no cells present were noted in the previously confluent EC and SMC culture wells. Cell structure was altered immediately after exposure to contrast, with normal structure recovered by 24 hours after exposure. CONCLUSION: This study demonstrates that brief exposure to contrast agents injures EC and SMC, altering their structure and decreasing proliferation for up to 7 days in vitro. This response is both dose and time dependent. EC are more severely affected by ionic contrast, and SMC are more severely affected by nonionic contrast. EC injury appears to be mediated by the osmolar effect of the contrast, but the effects of contrast on SMC seem to be due to a different mechanism.

Ambient pulsatile pressure modulates endothelial cell proliferation.

Many studies over the last decade have indicated that circulatory forces such as shear stress and cyclic strain can influence the endothelial cell (EC) phenotype. However, very little is known about the in vitro effects of pressure on EC. To study this, cultured bovine aortic EC were grown in custom designed pressure chambers with carefully regulated CO2/air environment. EC were exposed to either atmospheric, static (135 mmHg) or pulsatile pressure (160/110 mmHg). A pulsed pressure frequency of 60 cycles/min was maintained by computer-controlled solenoid valves, placed in series with pressure lines. EC proliferation was determined both by cell count after trypsin release on days 1,3 and 5 and by 3H-thymidine incorporation. By day 5, a significant decrease in cell number occurred in both pressure groups, confirmed by the thymidine studies. No changes were observed in cell morphology and cell viability as assessed by LDH activity studies. To investigate the mechanism of this effect, EC conditioned media from the three pressure conditions were transferred to non-exposed, control EC. Significant cell growth inhibition was demonstrated in the control EC group treated with conditioned media from EC cultured under pulsatile pressure conditions. This finding suggests that EC exposed to pulsatile pressure secrete an autocrine factor with growth inhibitory properties. This effect was not mediated by the growth factors TGFbeta and IL-1 as shown by Northern blot analysis and antibody-neutralization studies.

Extraarticular pigmented villonodular synovitis of the shoulder: a case report.

A rotator cuff tear was diagnosed in a 57-year-old woman based on physical examination and magnetic resonance imaging studies. At operation, an abnormal bursal lesion also was found. The lesion was completely extraarticular and was identified histologically as pigmented villonodular synovitis. The patient was treated with complete bursectomy and repair of the rotator cuff tear and remains asymptomatic 21 months after operation. Pigmented villonodular synovitis is a condition characterized by cell proliferation and deposition of hemosiderin into the lining tissues of joints, tendons, and bursae. The extraarticular form of pigmented villonodular synovitis is extremely rare and usually represents an extension of a primary intraarticular process. Only a few cases have been reported in which the lesion was found exclusively outside the joint with no intraarticular segment. In reviewing the literature, no case of exclusively extraarticular pigmented villonodular synovitis of the shoulder was found. The sequelae of extraarticular pigmented villonodular synovitis are poorly understood, but this lesion can be locally invasive, and if left untreated, may destroy surrounding tissues. Therefore, early diagnosis and treatment are important for optimal results.