The pulsating bubble surfactometer (PBS) is often used for in vitro characterization of exogenous lung surfactant replacements and lung surfactant components. However, the commercially available PBS is not able to dynamically track bubble size and shape. The PBS therefore does not account for bubble growth or elliptical bubble shape that frequently occur during device use. More importantly, the oscillatory volume changes of the pulsating bubble are different than those assumed by the software of the commercial unit. This leads to errors in both surface area and surface tension measurements. We have modified a commercial PBS through the addition of an image-acquisition system, allowing real-time determination of bubble size and shape and hence the accurate tracking of surface area and surface tension. Compression-expansion loops obtained with the commercially available PBS software were compared with those provided by the image-analysis system for dipalmitoylphosphatidylcholine, Infasurf, and Tanaka lipids (dipalmitoylphosphatidylcholine-palmitoyloleoylphosphatidyl-glycerol-palmitic acid, 68:22:9) at concentrations of 0.1 and 1.0 mg/ml and at frequencies of 1 and 20 cycles/min. Whereas minimum surface tension as determined by the image-analysis system is similar to that measured by the commercially available software, the maximum surface tension and the shapes of the interfacial area-surface tension loops are quite different. Differences are attributable to bubble drift, nonsinusoidal volume changes, and variable volume excursions seen with the modified system but neglected by the original system. Image analysis reveals that the extent of loop hysteresis is greatly overestimated by the commercial device and that an apparent, rapid increase in surface tension upon film expansion seen in PBS loops is not observed with the image-analysis system. The modified PBS system reveals new dynamic characteristics of lung surfactant preparations that have not previously been reported.
"Noodling" is an ancient form of hand fishing recently gaining in popularity as a hobby and sport. We present one of the first case reports of a noodling injury in an adolescent male seeking to land a large catfish, and also review the literature on catfish-related injuries.
A 7-year-old otherwise healthy Caucasian male presented to an outside hospital with a chief complaint of joint pain. The patient had a 3-day history of cough and rhinorrhea but had otherwise been in his usual state of health until he woke with right shoulder pain on the morning of admission. The shoulder pain progressively worsened throughout the day, and he subsequently developed severe left ankle pain and swelling. By the time the patient was evaluated at the outside hospital, he had developed a temperature of 1028F, was unable to ambulate, and had limited range of motion secondary to pain. There he received chest, right shoulder, and left ankle radiographs, a complete blood count, and blood culture. He was treated for pain and transferred to Cardinal Glennon Children's Medical Center for further evaluation.On review of systems, in addition to joint pain and fever, the patient complained of diffuse muscle soreness and upper respiratory tract symptoms. He had recently traveled to Colorado 1 week prior to onset of symptoms but had no history of tick bites. The patient's family recently had similar upper respiratory symptoms. The patient had no significant past medical history, was on no medications, and had no allergies. He was up-to-date on his immunizations, had not received any vaccines within the past 2 weeks, and had not been immunized against meningococcus.His axillary temperature was 99.88F, pulse 108/ min, respiratory rate 16/min, and blood pressure 88/ 52. He was alert, smiling, and in no acute distress. His sclera and pharynx were clear and neck was supple with full range of motion. There was no cervical lymphadenopathy. Cardiac, respiratory, abdominal, and neurological exams were all unremarkable. Musculoskeletal exam was significant for diffuse muscular tenderness. His right shoulder was extremely tender to palpation, with limited range of motion, but was without overlying erythema or warmth. The left ankle was markedly swollen, warm, and tender to palpation but without overlying erythema. He had evanescent, blanching macules present on bilateral lower extremities.Initial laboratory data showed a white blood cell count of 19.04 × 10 3 cells/mL (29% band forms, 52% neutrophils, 5% lymphocytes, 9% monocytes, 5% variant lymphocytes), with the rest of the complete blood count within normal limits. C-reactive protein was 4.6 mg/dL. Erythrocyte sedimentation rate was 18 mm/h. Chemistry panel and urinalysis were within normal limits, and rapid screen for influenza serotypes A and B were negative. The chest, right shoulder, and left ankle radiographs were all read as normal except for soft tissue swelling in the left ankle. Hospital CourseOn arrival, orthopedics was consulted to evaluate the need for arthrocentesis of the left ankle. Films from the outside hospital were reviewed, and orthopedics decided that joint fluid would not be aspirated, because of the recent upper respiratory tract infection and the polyarticular nature of the arthritis. The patient was admitted for further evaluation with a presumptiv...
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