Artificial urinary sphincters: plain radiography of malfunction and complications

Inflatable artificial urinary sphincters provide excellent voluntary continence. Eighty-four consecutive patients underwent implantation of artificial urinary sphincters for intractable urinary incontinence; 33 patients had 58 episodes of sphincter malfunction, and eight patients had eight complications involving a functional prosthetic sphincter. Retrospective analysis was performed to determine the value of plain radiography of the pelvis in patients with sphincter malfunction or complication. The cause of malfunction in the majority of patients was a system leak and subsequent loss of hydraulic fluid (31 occurrences; 53%). Plain radiography permitted correct identification of all instances of fluid leakage in patients with opacified prostheses. Plain radiographs were of no value in examining patients with nonopacified prostheses or the complications of cuff erosion or wound infection. Due to the low cost and noninvasive nature of plain radiography of the pelvis, we conclude that it should be used as the initial diagnostic modality in patients with previously opacified but currently dysfunctional artificial urinary sphincters.     

Shoulder instability: evaluation with MR imaging

Instability of the glenohumeral joint is a common cause of chronic shoulder pain and disability. One or more episodes of subluxation or dislocation may result in a tear, detachment, or attenuation of the glenoid labrum, stripping of the joint capsule from the scapula, or trauma to the tendons or muscles of the rotator cuff. A series of 27 shoulders examined with magnetic resonance (MR) imaging showed changes of glenohumeral instability, which were confirmed with open or arthroscopic surgery. MR imaging was capable of displaying common types of pathologic conditions resulting from instability, including labral trauma, capsular detachment, and retraction of the subscapularis muscle. MR imaging is a valuable diagnostic tool for the evaluation of glenohumeral instability.     

Low-dose flying spot digital radiography of the chest: sensitivity studies

Standard film examinations of the chest were compared with low-dose flying spot digital radiographic examinations obtained with a prototype unit in 174 patients. Analysis of pooled data from a double-blind study of 120 patients showed that film was more sensitive than digital images in the detection of pulmonary parenchymal abnormalities, that is, abnormal opacities, atelectasis, scar, and interstitial lung disease (P less than .05). Analysis of pooled data from a side-by-side study of 54 patients showed that the digital images were more sensitive than film in the detection of normal mediastinal and pleural soft-tissue contours, including the azygoesophageal recess, paraspinal line, and vertebral disk spaces (P less than .05). However, film was more sensitive than digital images in the detection of abnormalities of the lung, including scar, interstitial lung disease, septal lines, and the presence of vascular catheters (P less than .05). These findings suggest that low-dose flying spot digital radiography of the chest, as performed with this specific prototype unit, is not adequate to replace film in the detection of abnormalities of the lung parenchyma.     

Two serologic markers to monitor the engraftment, growth, and treatment response of human leukemias in severe combined immunodeficient mice

We have investigated human lactate dehydrogenase (LDH) isoenzymes and human nuclear matrix protein 41/7 (NMP 41/7) as potential serologic markers to monitor the course of human leukemia in severe combined immunodeficient (SCID) mice. Following the transplantation of 10(6) human acute lymphoblastic leukemia (ALL) Nalm-6 cells, human specific LDH isoenzymes were measurable in the serum of SCID mice as early as 7 days after transplantation, although serum total LDH increased in some animals as early as 5 days after transplantation. Human NMP 41/7 was measurable in all animals at day 15 after leukemia cell injection. Serum levels of total LDH, human specific LDH and NMP 41/7 increased progressively over time, reaching total LDH levels as high as 50,000 U/L at day 25 after transplantation. To determine whether the levels of LDH and NMP 41/7 in serum were a reflection of human tumor burden, we studied these serologic markers in SCID mice bearing measurable subcutaneous human neuroblastoma tumors, or compared the serum levels of these markers with the number of human leukemia CD10+ cells in the bone marrow of the SCID mice. The serum levels of total LDH, human specific LDH isoenzymes, and NMP 41/7 correlated well with tumor burden, and they drastically decreased or disappeared from serum after the human leukemia or neuroblastoma cells were selectively killed with a single intravenous (IV) injection of 1 to 3 micrograms diphtheria toxin (DT) (the cellular receptor for DT is present on human cells, but not on mouse cells). Paraplegic mice with central nervous system leukemia completely recovered after DT treatment. We conclude that measurements of serum levels of total LDH, human LDH isoenzymes, and NMP 41/7 are sensitive, quantitative, rapid, and easy to perform serologic methods useful to monitor the engraftment, progression, and treatment response of human leukemia in SCID mice.     

Amyloidosis of heart and liver: comparison of Tc-99m pyrophosphate and Tc-99m methylene diphosphonate for detection

A prospective, comparative study was made of the efficacy of technetium-99m pyrophosphate (Tc PYP) and technetium-99m methylene diphosphonate (Tc MDP) in detecting soft-tissue amyloidosis. Tc PYP and Tc MDP scans were obtained within ten-day intervals in seven patients with histologically proven amyloidosis. Tc PYP was a better scanning agent for soft-tissue amyloidosis in all patients. Cardiac and hepatic involvement were proved by autopsy in one patient. Involvement of the heart was confirmed by echocardiography in five patients. The potential use of Tc PYP scanning as a screening test for soft-tissue amyloidosis is discussed.