Post-transplantation lymphoproliferative disease

Trace element profile analysis detects and quantifies the presence of several metals simultaneously at low concentrations in the body. In occupational medicine, it may be used to monitor exposure or to evaluate suspected toxicity. Clinical interpretation is often difficult because, with the exception of lead and possibly cadmium, there is little firm information on toxicity thresholds. For these tests, the reference ranges typically reflect low levels of exposure in the general population and it is expected that workers handling metals in occupations such as welding and industries such as steelmaking will have higher levels. Interpretation requires some knowledge of the toxicokinetics of the metal of interest and the preferred medium for analysis for each: serum, whole blood or urine (preferably 24-hour collection). Trends are often more informative than concentrations at one time. Trace element values are reported together with a reference range which must be distinguished from the normal range of other clinical tests. As a practical matter, the greatest interpretation problems tend to be found with manganese because serum levels have a poor correlation with both recent exposure and neurological symptoms. Molybdenum and vanadium are often found to be elevated among workers exposed to metals who show no evidence of clinical illness. Interpretation of the trace element profile analysis overall when an elevation occurs generally requires close attention to the pattern of elevation, clinical context, absolute and relative magnitude of the elevation and knowledge of the exposure history.     

Intraoperative echocardiography is indicated in high-risk coronary artery bypass grafting

BACKGROUND: Intraoperative echocardiography is a valuable monitoring and diagnostic technology used in cardiac surgery. This reports our clinical study of the usefulness of intraoperative echocardiography to both surgeons and anesthesiologists for high-risk coronary artery bypass grafting. METHODS: From March to November 1995, 82 consecutive high-risk patients undergoing coronary artery bypass grafting were studied in a four-stage protocol to determine the efficacy of intraoperative echocardiography in management planning. Alterations in surgical and anesthetic/hemodynamic management initiated by intraoperative echocardiography findings were documented in addition to perioperative morbidity and mortality. RESULTS: Intraoperative echocardiography initiated at least one major surgical management alteration in 27 patients (33%) and at least one major anesthetic/hemodynamic change in 42 (51%). Mortality and the rate of myocardial infarction in this consecutive high-risk study population using intraoperative echocardiography and in a similar group of patients without the use of intraoperative echocardiography was 1.2% versus 3.8% (not significant) and 1.2% versus 3.5% (not significant), respectively. CONCLUSIONS: We conclude that when all of the isolated diagnostic and monitoring applications of perioperative echocardiography are routinely and systematically performed together, it is a safe and viable tool that significantly affects the decision-making process in the intraoperative care of high-risk patients undergoing primary isolated coronary artery bypass grafting and may contribute to the optimal care of these patients.     

Atomic Bond Deficiency Defects in Amorphous Metals

Atomic bond deficiency (BD) is considered to be characteristic structural defects in amorphous metals. They are the necessary feature of local atomic configurations that facilitate various atomic transports under different driving forces. Compared with vacancies in crystalline solids, they are ??small?? in terms of their formation energies, volume costs, and elementary steps involved in atomic transport. This article reviews the authors?? recent efforts made to analyze how various local configurations containing BD are related to amorphous metal??s unique characteristics, such as glass transition, diffusion, shear flow, and structural relaxation.     

Relationship between feed withdrawal and viscera condition of broilers

An AIDS patient with disseminated histoplasmosis who improved during treatment with fluconazole but remained fungemic and subsequently relapsed is described. Isolates obtained from blood during therapy showed a progressive increase in fluconazole MIC from 0.625 to 20 micrograms/ml. The pretreatment, or parent, isolate and the posttreatment, or relapse, isolate demonstrated identical genetic patterns by PCR fingerprinting with three different primers. Fluconazole was less potent inhibitor of the growth of the relapse isolate than of the pretreatment isolate (50% inhibitory concentration [IC50] = 11.7 microM), while itraconazole was more potent (relapse isolate IC50 = 0.0011 microM versus pretreatment isolate IC50 = 0.0064 microM). Neither the increased sensitivity to itraconazole nor the decreased activity of fluconazole on the growth of the relapse isolate results from changes in the intracellular content of these agents. To reach 50% inhibition of ergosterol synthesis in both the parent and relapse isolates, about 2 nM itraconazole was needed; with fluconazole, 50% inhibition was achieved at 20.9 microM and 55.5 microM, respectively. Resistance to fluconazole may develop during treatment and results from decreased sensitivity of ergosterol synthesis.     

A note on inter-arm intrachange patterns resulting from dual-arm fish painting

Renal-cell cancer comprises a heterogeneous group of tumors, which currently can be sub-divided into morphologically distinct entities, each characterized by a specific combination of genetic changes. Sarcomatoid transformation might occur in any of the sub-types, resulting in tumors consisting of both carcinomatous and sarcomatous components. The specific diagnosis of these neoplasms, as to tumor sub-type, is usually made on the histologic properties of the carcinomatous tissue present. However, this might not reflect the true nature of the sarcomatous component. Since the genetic changes associated with the development of the different sub-types of renal-cell cancer are well established, this knowledge might serve as a tool in diagnosing sarcomatoid tumors. Assessing the genetic constitution of the latter may lead to correct diagnosis. It may also provide valuable information about the genetic changes associated with sarcomatoid transformation. Hence we performed a genetic characterization of a case of sarcomatoid renal-cell cancer, histologically diagnosed as being of the chromophilic type. The observed genetic changes included loss of 3p, 6q, 8p, 9, 13, 14 and 17p, and gain of 5, 12 and 20, as well as a mutation in the coding region of the p53 gene. This combination of genetic changes points to clear-cell rather than chromophilic origin of the sarcomatoid tumor investigated, indicating that the genetic constitution of sarcomatoid tumors may be a more reliable indicator of tumor sub-type than histologic appearance.     

Prenatal ethanol exposure decreases GAP-43 phosphorylation and protein kinase C activity in the hippocampus of adult rat offspring

Consumption of moderate quantities of ethanol during pregnancy produces deficits in long-term potentiation in the hippocampal formation of adult offspring. Protein kinase C (PKC)-mediated phosphorylation of the presynaptic protein GAP-43 is critical for the induction of long-term potentiation. We tested the hypothesis that this system is affected in fetal alcohol-exposed (FAE) rats by measuring GAP-43 phosphorylation and PKC activity in the hippocampus of adult offspring of rat dams that had consumed one of three diets throughout gestation: (a) a 5% ethanol liquid diet, which produced a maternal blood ethanol concentration of 83 mg/dl (FAE); (b) an isocalorically equivalent 0% ethanol diet (pair-fed); or (c) lab chow ad libitum. Western blot analysis using specific antibodies to PKC-phosphorylated GAP-43 revealed that FAE rats had an approximately 50% reduction in the proportion of phosphorylated GAP-43. Similarly, we found that PKC-mediated incorporation of 32P into GAP-43 was reduced by 85% in hippocampal slices from FAE rats compared with both control groups. FAE animals also showed a 50% reduction in total hippocampal PKC activity, whereas the levels of six major PKC isozymes did not change in any of the diet groups. These results suggest that GAP-43 phosphorylation deficits in rats prenatally exposed to moderate levels of ethanol are not due to alterations in the expression of either the enzyme or substrate protein, but rather to a defect in kinase activation.     

Vortex core size in submonolayer superfluid4He films

The superfluid transition of⁴He films adsorbed on 500 Å diameter slip-cast alumina powder is measured with a torsion oscillator technique for films with transition temperatures between 50 and 700 mK. The transitions are found to be controlled by the universal Kosterlitz- Thouless critical line, but a strong increase in the broadening of the transition is observed for the thinnest films. Analysis in terms of vortex pair excitations shows that this broadening results from a vortex core size that increases rapidly as the film is thinned, scaling roughly with the interparticle spacing of the superfluid submonolayer. Third sound modes are identified in the dissipation, in addition to a broad peak from the vortex unbinding. This system provides evidence of a three-dimensional superfluid transition mediated by vortex excitations.     

Effect of an aerosol deposition pattern in the lung on the counting efficiency of a large area germanium detector array

The Human Monitoring Laboratory has extended the use of sliced lungs containing planar sources to simulate heterogeneous radionuclide deposition patterns. This work examined two deposition patterns and their effect on the counting efficiency of low-energy photons. The results have shown that heterogenous distributions can be difficult to detect in some cases and can still lead to large uncertainties (up to a factor of 2.5) in the activity estimate, especially at low photon energies. At higher energies ( approximately 60 keV), the effect of the heterogeneous distribution is greatly reduced and errors in the activity estimate reduced to approximately 25%. The presence of a heterogenous distribution can be detected by comparing the ratio of the individual detector counts with the expected values obtained from measuring multiple lungs sets that contained a homogeneous distribution. The distributions tested in this paper were detectable (at 2sigma) as heterogeneous by two of the four detectors in the counting array.