Three biochemical tests for the diagnosis of pheochromocytoma were evaluated in 24 patients with proved tumors and 40 patients whose clinical picture was suspect but who had no evidence of the disease. Measurement of resting, supine plasma catecholamines (by radioenzymatic assay) was more useful than either 24-hour urinary vanillylmandelic acid (VMA) or metanephrines or both. In only one of 23 patients with pheochromocytoma were plasma catecholamines within the range of those in patients without pheochromocytoma, as compared with urinary VMA in 11 of 22, urinary metanephrines in five of 22 and both metabolites in three of 22. These studies reaffirm the value of plasma catecholamines in the diagnosis of pheochromocytoma and indicate that urinary catecholamine metabolites are less useful. The poor correlation between the height of arterial pressure and circulating levels of catecholamines suggests that the regulation of arterial pressure in pheochromocytoma is complex.
The results of therapy for 78 patients with disseminated renal cell carcinoma are evaluated. Symptoms related to the primary tumor were noted in only 28 per cent of the patients and were not difficult to manage in those patients not undergoing nephrectomy. Adjuctive nephrectomy, therefore, is a more appropriate term than palliative nephrectomy when referring to removal of the primary tumor as part of an aggresive combined therapeutic approach. Of patients receiving an adjunctive nephrectomy those with osseous metastases only had a better 1-year survival rate (36 per cent) than those with metastases to other sites (18 per cent). Complete regression of metastases was noted in 12 per cent of patients treated with medroxyprogesterone acetate and adjunctive nephrectomy. The role of adjunctive nephrectomy combined with embolic infarction, hormonal therapy, chemotherapy and/or immunotherapy is discussed.
Phospholipase A2 associated neurodegeneration (PLAN) is a major phenotype of autosomal recessive Neurodegeneration with Brain Iron Accumulation (NBIA). We describe the clinical phenotypes, neuroimaging features and PLA2G6 mutations in 5 children, of whom 4 presented with infantile neuroaxonal dystrophy (INAD). One other patient was diagnosed with the onset of PLAN in childhood, and our report highlights the diagnostic challenges associated with this atypical PLAN subtype. In this series, the neuroradiological relevance of classical PLAN features as well as apparent claval hypertrophy’ is explored. Novel PLA2G6 mutations were identified in all patients. PLAN should be considered not only in patients presenting with a classic INAD phenotype but also in older patients presenting later in childhood with non-specific progressive neurological features including social communication difficulties, gait disturbance, dyspraxia, neuropsychiatric symptoms and extrapyramidal motor features.
h Proteus mirabilis forms dense crystalline biofilms on catheter surfaces that occlude urine flow, leading to serious clinical complications in long-term catheterized patients, but there are presently no truly effective approaches to control catheter blockage by this organism. This study evaluated the potential for bacteriophage therapy to control P. mirabilis infection and prevent catheter blockage. Representative in vitro models of the catheterized urinary tract, simulating a complete closed drainage system as used in clinical practice, were employed to evaluate the performance of phage therapy in preventing blockage. Models mimicking either an established infection or early colonization of the catheterized urinary tract were treated with a single dose of a 3-phage cocktail, and the impact on time taken for catheters to block, as well as levels of crystalline biofilm formation, was measured. In models of established infection, phage treatment significantly increased time taken for catheters to block (ϳ3-fold) compared to untreated controls. However, in models simulating early-stage infection, phage treatment eradicated P. mirabilis and prevented blockage entirely. Analysis of catheters from models of established infection 10 h after phage application demonstrated that phage significantly reduced crystalline biofilm formation but did not significantly reduce the level of planktonic cells in the residual bladder urine. Taken together, these results show that bacteriophage constitute a promising strategy for the prevention of catheter blockage but that methods to deliver phage in sufficient numbers and within a key therapeutic window (early infection) will also be important to the successful application of phage to this problem.A frequent complication associated with long-term urethral catheterization is the encrustation and blockage of catheters due to infection with Proteus mirabilis, which can be isolated from around 45% of catheter-associated urinary tract infections (CAUTI) (1, 2). Blockage stems from the ability of P. mirabilis to form dense biofilms on catheter surfaces and the production of a potent urease enzyme which generates ammonia through hydrolysis of urea (1,3,4). Ammonia production elevates urinary pH, causing the precipitation of calcium and magnesium phosphates and the subsequent formation of crystals which become trapped within developing biofilms (1, 5). Once embedded in the biofilm, crystal growth is stabilized and enhanced by the biofilm matrix (6, 7). As this process continues, the biofilm gradually becomes mineralized, leading to development of extensive crystalline biofilm structures which ultimately block catheters (1, 5). If blockage is unnoticed, it can lead to reflux of infected urine to the upper urinary tract and the onset of serious clinical complications, including pyelonephritis, septicemia, and shock (1, 8).Although catheters containing antimicrobial coatings are currently available, their efficacy in preventing infection during even short-term use remains questionable, and all...
NOLD, 2 in 1894, reported on a series of hydrocephalic individuals exhibiting, also, congenital defects in the region of the hindbrain. Although these cases varied considerably, the essential condition was that of a herniation of tongue-like processes of cerebellar tissue into the cervical canal. In 1891 and 1896 Chiari 5,6 described a series of similar cases in which a distorted medulla, as well as cerebellar tissue, was within the cervical canal. In these cases the tongues of cerebellar tissue were so bound down to the medulla that usually there was interference with the passage of cerebrospinal fluid through the roof of the 4th ventricle. Schwalbe and Gredig 21 suggested that such cases formed a logical entity which they called the Arnold-Chiari malformation.The frequent association of an Arnold-Chiari malformation with myeloschisis has led certain workers to postulate a causal interrelation between the two conditions (see, for example, Penfield and Coburn, Is and Lichten-steinl2). It is well known that, during the middle trimester of gestation, the spinal column increases in length more rapidly than the spinal cord. 11,~6,22 Normally at this time the cephalic part of the cord is more securely anchored than its caudal region. This is not only because of its fixation by the brain within the developing cranium, but also because of the relatively more advanced state of development of the spinal nerves cephalically. As a result of the differential in rate of growth and the cephalic anchorage, the lumbosacral part of the cord slides cephalad within the neural canal with the concomitant elongation of the lumbosacral nerve roots to form the cauda equina. If during this period there is a lumbar or a sacral myeloschisis the spinal cord has an abnormal point of fixation caudally. This undoubtedly subjects it to abnormal traction, and the inference that such traction might pull the medulla and cerebellum caudad through the foramcn magnum, is plausible and has all the allure of a "simple mechanical explanation" of the genesis of the Arnold-Chiari malformation. The validity of the traction interpretation has been called in question by a number of workers. 1,3,13-15 MATERIAL There are available in the University of Michigan Embryological Collection five human embryos showing various stages in the development of * The participation of Dr. Stewart in this work was made possible through a summer research fellowship granted to him while he was a medical student. ~85
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