Somatic growth and developmental functioning in children receiving prolonged home total parenteral nutrition

Growth and psychomotor development in nine infants receiving prolonged home total parenteral nutrition (TPN) were studied longitudinally from infancy to 3 years of age. Although these children had received TPN for, on average, 79% of their lives, normalization of somatic growth occurred by 2 years of age in all of them. Three children maintained average or above average levels of developmental performance over the 3-year study period. Another four children had initially delayed development but average or above average developmental scores by 18 months. In two children the rate of development gradually slowed without obvious cause, so that by 3 years they functioned in the below average to mildly retarded range.     

The Utah paradigm of skeletal physiology: an overview of its insights for bone, cartilage and collagenous tissue organs

In a 1960 paradigm of skeletal physiology, effector cells (chondroblasts, fibroblasts, osteoblasts, osteoclasts, etc.) regulated by nonmechanical agents wholly determined the architecture, strength, and health of bones, joints, fascia, ligaments, and tendons. Biomechanical and tissue-level phenomena had no roles in that paradigm. Subsequent studies and evidence slowly revealed skeletal tissue-level mechanisms and their functions, including biomechanical ones, as well as "game rules" that seem to govern them. That slow discovery process found that effector cells are only parts of tissue-level mechanisms, as kidney cells are only parts of nephrons and wheels are only parts of cars. Normally all those things help to determine skeletal architecture, strength, and health, and adding them to the 1960 paradigm led to the still-evolving Utah paradigm of skeletal physiology that concerns, in part, how load-bearing skeletal organs adapt to the voluntary mechanical loads on them. That caused controversies this article does not try to resolve; instead, it describes some issues they concern. In that regard, controversy can depend on how one assesses the relevance of facts to a problem more than on their accuracy. If a paradigm added new facts to a former one and the new one's advocates viewed all those facts as relevant, but the former's advocates questioned the relevance of some of the new facts, their views about a problem could differ even though each view depended on accurate facts. Readers would make their own judgments about the bearing of those ideas on this article's content. Received: October 5, 1999 / Accepted: January 13, 2000     

Cellular uptake and subcellular distribution of mercury in chick embryonic retinal cell aggregates

Cellular uptake and subcellular distribution of mercury (203HgCl2) were determined in the chick embryonic retinal cell aggregation system. The accumulation of mercury was dependent upon its concentration in the medium. The uptake was rapid; a maximum deposition of mercury at 5 microM occurred within the first 30 min followed by a decline. Accumulation of mercury at 1 microM was constant between 15 min and 24 hr. The subcellular distribution of mercury was observed in the following order: nuclei and cell debris greater than mitochondria-lysosomes greater than 105,000g supernatant greater than microsomes. The activity of acid phosphatase markedly decreased in the aggregates treated with mercury at 50 to 100 microM for 24 hr. Low concentrations of mercury at 0.5 to 5 microM showed an inhibition of this enzyme activity in a cell-free system. The results indicate a relationship between the amount of mercury in the cells and the toxicity it produced on the retinal cell aggregation system.     

The current role of thymectomy for myasthenia gravis

Myasthenia gravis is an autoimmune disease characterized by muscle weakness and fatigability due to a reduction in available acetylcholine receptors at the neuromuscular junction. Treatment with anticholinesterase drugs and corticosteroids has improved the prognosis for patients with this disease. However, controversy continues concerning the indications for thymectomy. During a 9 year period, 27 patients who underwent thymectomy by median sternotomy were reviewed. Eighty-one percent of these patients benefited from the procedure. Clinical improvement did not correlate with age, sex, duration of symptoms, severity of disease or thymic histology. This suggests that the indications for thymectomy should be liberalized to include most patients with generalized myasthenia who fail to respond readily to conventional medical therapy. The importance of immunosuppression and plasmapheresis in the therapy of myasthenia gravis awaits further delineation of the immune defect associated with the disease.     

Evaluation of a rapid bacteriuria screening instrument

A newly modified, semiautomated instrument (Bacteriuria detection device (BDD) designed to detect the presence of bacteriuria in less than 3 min was compared to quantitative urine culture plating techniques. The instrument consists of a self-enclosed vacuum—filtration—staining system in which a 1-ml urine filtrate is stained on a filter. The resulting color determines the quantitation. Of the total of 525 clinical urine specimens tested, 66 (12.6%) were uninterpretable due to pigment deposition or inability to complete the filtering process (clogging of the filter). Of the remaining 459 specimens, 93 (20.3%) had a plate quantitation colony count of 10⁵ colony-forming units (CFU)/ml or more. The BDD detected 94.2% of these positive specimens if only significant pathogens were included (85% if specimens that were probably contaminated were also included). For specimens containing significant pathogens at 10⁴–10⁵ CFU/ml, the BDD detection rate was 41%. The device detected most (94.3%) gram-negative bacilli and enterococci at colony counts of 10⁵ CFU/ml or more. In addition, the BDD accurately detected 95.6% of specimens with no growth or fewer than 10⁴ CFU/ml. With several proposed modifications, these results suggest that this instrument is potentially useful as a urine screening device in a select population.     

Identification of fungal casts in a patient with renal candidiasis

Since the treatment of fungal infections with amphotericin B may result in significant nephrotoxicity, better methods for discriminating between life-threatening and more benign fungal infections are needed. Recently numerous fungal casts were identified in the urine of a patient who had undergone renal allograft transplantation. The recognition of fungal casts permitted an unequivocal diagnosis of systemic fungal infection. Successive examinations of the patient's urinary sediment provided an excellent monitor of the response to treatment. The cytologic features of fungal casts are described. Since systemic fungal infections often involve the kidney, screening for fungal casts may have significant clinical applicability.     

Long-term intravenous infusion of antiarrhythmic drugs using a totally implanted drug delivery system

In vitro and in vivo testing was performed to establish the feasibility of a totally implantable pump system to deliver antiarrhythmic agents. In vitro flow characteristics suggested predictable day to day delivery with acceptably small variations in flow with changes in reservoir volume or temperature. During 3 months of in vitro testing, procainamide and bretylium were found suitable for long-term delivery. Delivery of lidocaine was limited by high viscosity and corrosion of steel elements within the pump. The pump was implanted in a subcutaneous pocket in four dogs. Procainamide (0.5 g/ml), delivered at 4 ml/day (70 mg/kg body weight per day), provided a mean steady state drug concentration of 5.3 μg/ml. Bretylium (50 mg/ml), delivered at 8 ml/day (13 mg/kg per day), provided a steady state concentration of 0.8 μg/ml (range 0.4 to 1.4). Long-term intravenous administration of therapeutic doses of bretylium and procainamide with this delivery system has been demonstrated in dogs and appears to be feasible in human subjects.