Association between travel distance and overall survival among patients with adrenocortical carcinoma.

BACKGROUND AND OBJECTIVES: Regionalization of care is associated with improved perioperative outcomes after adrenalectomy. However, the relationship between travel distance and treatment of adrenocortical carcinoma (ACC) is unknown. We investigated the association between travel distance, treatment, and overall survival (OS) among patients with ACC. METHODS: Patients diagnosed with ACC between 2004 and 2017 were identified with the National Cancer Database. Long distance was defined as the highest quintile of travel (≥42.2 miles). The likelihood of surgical management and adjuvant chemotherapy (AC) were determined. The association between travel distance, treatment, and OS was evaluated. RESULTS: Of 3492 patients with ACC included, 2337 (66.9%) received surgery. Rural residents were more likely to travel long distances for surgery than metropolitan residents (65.8% vs. 15.5%, p < 0.001), and surgery was associated with improved OS (HR 0.43, 95% CI 0.34-0.54). Overall, 807 (23.1%) patients received AC with rates decreasing approximately 1% per 4-mile travel distance increase. Also, long distance travel was associated with worse OS among surgically treated patients (HR 1.21, 95% CI 1.05-1.40). CONCLUSIONS: Surgery was associated with improved overall survival for patients with ACC. However, increased travel distance was associated with lower likelihood to receive adjuvant chemotherapy and decreased overall survival.

High malignancy rate in the absence of viral prophylaxis after kidney transplantation in Sudan.

BACKGROUND: Kidney transplantation in Sudan is funded by the government. Cytomegalovirus prophylaxis is provided for patients who receive biological induction or have recipient-negative donor-positive cytomegalovirus serology. Doctor Selma Center for Kidney Diseases joined the national kidney transplant program in May 2019. Since then, we observed the frequent occurrence of cancer in patients who received modest immunosuppression without viral prophylaxis. METHODS: We retrospectively divided kidney transplant recipients between 2019 and 2021 into two groups according to cytomegalovirus prophylaxis and compared tumor occurrence rates. RESULTS: The first group included 77 patients who did not receive biological induction or cytomegalovirus prophylaxis. The second group included 92 patients who received valganciclovir for 3-6 months. There was no other antiviral treatment except entecavir for chronic hepatitis B virus infection in eight patients. Five patients in the first group developed malignancy. The first patient presented eight months post-transplant with Kaposi sarcoma of the stomach and responded to treatment with sirolimus. The second patient presented nine months post-transplant with cutaneous Kaposi sarcoma and also responded to sirolimus. Two patients presented two and four months post-transplant with aggressive non-cutaneous Kaposi sarcoma that involved the gastrointestinal tract and lymphatic system and died soon afterwards. The fifth patient presented three years post-transplant with non-Hodgkin lymphoma of the duodenum and is currently receiving chemotherapy. Malignancy rate (6.5% vs 0.0%, P = 0.02) and Kaposi sarcoma rate (5.2% vs 0.0%, P = 0.04) were significantly higher in the first group. CONCLUSION: In Sudan, omitting valganciclovir prophylaxis after kidney transplantation was associated with a high rate of virus-induced malignancy.

Sensitivity of lateral flow technique for diagnosis of canine parvovirus.

In this study, we devised a nanogold lateral flow immunoassay (LFA-CPV antigen test) for detecting canine parvovirus (CPV) in living attenuated CPV vaccines. We conducted instrumental characterization of the prepared nanogold particles and the developed LFA-CPV antigen test was rigorously evaluated for its performance verification including limit of detection, sensitivity, specificity, selectivity and accuracy. The LFA-CPV antigen test demonstrated strong performance when assessed against qPCR using different batches of live attenuated CPV vaccines, indicated a sensitivity of 96.4%, specificity of 88.2%, and an overall accuracy of 95%. These results suggest that the developed LFA-CPV antigen test could serve as a viable alternative for evaluation live attenuated CPV vaccines, and provide it as a point of care test for CPV diagnosis, offering a potential substitute for traditional laboratory methods, particularly qPCR.

NMR-derived models of amidopyrine and its metabolites in complexes with rabbit cytochrome P450 2B4 reveal a structural mechanism of sequential N-dealkylation.

To understand the molecular basis of sequential N-dealkylation by cytochrome P450 2B enzymes, we studied the binding of amidopyrine (AP) as well as the metabolites of this reaction, desmethylamidopyrine (DMAP) and aminoantipyrine (AAP), using the X-ray crystal structure of rabbit P450 2B4 and two nuclear magnetic resonance (NMR) techniques: saturation transfer difference (STD) spectroscopy and longitudinal (T(1)) relaxation NMR. Results of STD NMR of AP and its metabolites bound to P450 2B4 were similar, suggesting that they occupy similar niches within the enzyme's active site. The model-dependent relaxation rates (R(M)) determined from T(1) relaxation NMR of AP and DMAP suggest that the N-linked methyl is closest to the heme. To determine the orientation(s) of AP and its metabolites within the P450 2B4 active site, we used distances calculated from the relaxation rates to constrain the metabolites to the X-ray crystal structure of P450 2B4. Simulated annealing of the complex revealed that the metabolites do indeed occupy similar hydrophobic pockets within the active site, while the N-linked methyls are free to rotate between two binding modes. From these bound structures, a model of N-demethylation in which the N-linked methyl functional groups rotate between catalytic and noncatalytic positions was developed. This study is the first to provide a structural model of a drug and its metabolites complexed to a cytochrome P450 based on NMR and to provide a structural mechanism for how a drug can undergo sequential oxidations without unbinding. The rotation of the amide functional group might represent a common structural mechanism for N-dealkylation reactions for other drugs such as the local anesthetic lidocaine.

Surgical Treatment of Multifocal Pulmonary Mucormycosis.

Mucormycosis is a devastating opportunistic fungal infection to which the immunosuppressed are particularly vulnerable. We report the case of a 60-year-old man who was found to have multifocal pulmonary mucormycosis 10 weeks after concomitant heart and kidney transplantation. Despite appropriate antifungal therapy, the infection progressed rapidly and soon involved critical pulmonary vasculature. He successfully underwent staged operative resection of his pulmonary mucormycosis without recurrence of infection. Although surgical debridement of pulmonary mucormycosis is typically reserved for localized disease, this case demonstrates that surgical intervention should be considered as an adjunct to antifungal therapy in multifocal disease.

Experimental addition of nitrogen to a whole forest ecosystem at Gårdsjön, Sweden (NITREX): Nitrate leaching during 26 years of treatment.

Chronic high deposition of nitrogen (N) to forest ecosystems can lead to increased leaching of inorganic N to surface waters, enhancing acidification and eutrophication. For 26 years nitrogen has been added as ammonium nitrate (NH4NO3) at 40 kg N ha-1 yr-1 to a whole forested catchment ecosystem at Gårdsjön, Sweden, to experimentally simulate the transition from a N-limited to N-rich state. Over the first 10 years of treatment there was an increasing amount of nitrate (NO3-) and to a lesser extent ammonium (NH4+) lost in runoff, but then N leaching stabilised, and for the subsequent 16 years the fraction of N added lost in runoff remained at 9%. NO3- concentrations in runoff were low in the summer during the first years of treatment, but now are high throughout the year. High frequency sampling showed that peaks in NO3- concentrations generally occurred with high discharge, and were enhanced if high discharge coincided with occasions of N addition. Approximately 50% of the added N has gone to the soil. The added N is equivalent to 140 years of ambient N deposition. At current ambient levels of N deposition there thus appears to be no immediate risk of N saturation at this coniferous forest ecosystem, and by inference to other such N-limited forests in Scandinavia.

A novel adaptor-like protein which is a substrate for the non-receptor tyrosine kinase, BRK.

The brk gene encodes a non-receptor tyrosine kinase that has been found to be overexpressed in approximately two thirds of breast tumours. Using a yeast two-hybrid based screen, we have cloned cDNAs encoding a novel protein, BKS, that is a substrate for the kinase activity of BRK and has the characteristics of an adaptor protein. BKS possesses an N-terminal PH-like domain followed by an SH2-like domain. In co-transfection experiments, high levels of phosphotyrosine were observed on BKS and BRK was found to be associated with BKS, both of which were dependent on the catalytic activity of BRK. The phosphorylation of and association with BKS by BRK was also dependent on the SH2-like domain present within BKS. In addition, BKS recruited an unidentified 100 kDa protein that was also phosphorylated on tyrosine residues in the presence of BRK. We have determined that the BKS protein is expressed in most adult human tissues. Oncogene (2000) 19, 4273 - 4282

Epstein-Barr virus nuclear antigen (EBNA)3C is an immortalizing oncoprotein with similar properties to adenovirus E1A and papillomavirus E7.

Epstein-Barr virus (EBV) requires six genes to efficiently immortalize human B cells. We have shown that one of these, EBNA3C, can cooperate with activated (Ha-)ras in co-transfection assays to immortalize and transform rat embryo fibroblasts (REFs). EBNA3C also augmented transformation by (Ha-)ras and a mutant p53 to a similar extent as human papilloma virus E7. As with E7 this effect was not inhibited by cotransfection with the cyclin-dependent kinase inhibitor (CDKI), a p16INK4A, which can normally activate the retinoblastoma protein (pRb) and induce growth arrest. Also like E7/ras and E1A/ras transformed cells the EBNA3C/ras transformants are very susceptible to apoptotic cell death. In vitro EBNA3C binds to pRb in a manner which is dependent on the integrity of the pocket domain; this suggests that EBNA3C, even though it lacks the LXCXE pRb binding motif found in E7 and E1A, may interact with pRb in vivo. We conclude that EBNA3C functions as an oncoprotein which directs cell cycle progression through the G1 phase restriction point when conditions might signal arrest. For the first time this demonstrates that EBV encodes a protein, functionally but not necessarily mechanistically, similar to the pRb-neutralizing nuclear antigens encoded by the 'small' DNA tumor viruses.

Interaction of amosite and surface-modified amosite with a V79-4 (Chinese hamster lung) cell line.

We have been examining a number of chemically modified mineral fibers, derived from amosite asbestos, by in vitro methods to clarify the role of the fiber surface in determining biological activity. The various fibers have identical size distributions but differ in their affinities for components of the cell membrane. They were treated with boiling toluene or chemically modified by treatment with alkyldimethylchlorosilanes (R = C8, C18) that react with free-surface hydroxyl groups to form the corresponding siloxanes. Fibers in MEM supplemented with 15% fetal calf serum were added to a suspension of V79-4 cells labeled with tritiated thymidine and the mixture was incubated. Aliquots of this mixture were spun down on a density gradient to determine the degree of cell-fiber interaction. At 37 degrees C native amosite (UICC standard) stuck to cells within 15 min of incubation, and the amount of sticking was maximum within 70 min. Decreasing the temperature decreased the amount of sticking, and at 20 degrees C no sticking was observable. The chemically modified amosite and the amosite treated with boiling toluene did not stick to the cells even after 70 min. Soaking the toluene-treated amosite with aqueous solutions at room temperature for 48 hr produced a material that had the same sticking properties as the original untreated fiber. These results indicate that the silanol content, and possibly the degree of hydration of the fiber surface, is important for a fiber to stick to a cell surface.

In vitro methods to determine the biological activities of particulate mineral pollutants.

The biological effects of mineral particles in both macrophage-like and fibroblast cell lines are described. The several macrophage-like cell lines available are all sensitive to the toxic effects of silica, but not all are equally affected by mineral fibres. The effects of the fibres are partially determined by their ability to interact with the cell surface and this has been monitored by density gradient centrifugation of cell-fibre mixtures. It has been found that the adhesion between fibres and cells is similar to that between cells and normal tissue culture surfaces. This adhesion requires fibronectin and involves arginine-glycine-aspartate (RGD) receptors on the cell surface. Using polylysine to render the fibres positively charged, short-term responses to fibres may be studied and this has revealed a size-dependent activation of the second messenger pathways. Such a response is difficult to monitor in normal cultures, as the response is asynchronous, but the use of microfluorimetric methods has enabled studies on single cells.

Factors affecting the interaction of asbestos fibres with mammalian cells: a study using cells in suspension.

One of the earliest events in pathogenesis by mineral fibres must be an interaction between fibre and cell surfaces. Using a simple technique in which cells in suspension were incubated with fibres and adhesion monitored by separation on a density gradient it has been shown that such interactions occur through two distinct mechanisms. The first, a charge-mediated effect, occurs with positively charged fibres such as chrysotile asbestos. The second, with amphibole or glassy fibres, is mediated by fibronectin which first binds to the fibre. The bound protein then attaches to RGD receptors on the cell surface; calcium and magnesium ions are necessary for optimal adhesion. The RGD receptors bind to a tripeptide region on the protein and small peptides containing the RGD sequence block fibre-cell interaction. If the surface silanol groups on the fibre were chemically coupled to trialkylsilyl groups then interaction was slowed.

Transcriptional activation by p53 correlates with suppression of growth but not transformation.

The tumor suppressor protein p53 shows growth and transformation suppression functions that are frequently lost by mutant proteins detected in cancers. Using a large series of p53 mutants, we have demonstrated an excellent correlation between transcriptional activation and growth suppression in p53-null human cells. Not all transcriptionally active mutants retain the ability to suppress transformation in primary rodent cells, however, and two tumor-derived point mutants displayed some evidence of both transforming and transactivating activity. Transformation by these mutants was not mediated by transdominant repression of endogenous p53 transactivating function, and cell lines expressing these p53 proteins showed elevated p53 transcriptional activity. Our results suggest that activation of transcriptional regulation by p53 will not necessarily result in tumor suppression.

The effects of heating and devitrification on the structure and biological activity of aluminosilicate refractory ceramic fibres.

Three grades of ceramic fibre have been examined for their composition, structures and biological effect in several in vitro assay systems. The fibres were examined in the 'as-manufactured' state and after heating at 1200 and 1400 degrees C. Devitrification of the fibres at 1200 degrees C probably gave mullite crystals on the surface and caused the formation of the high-temperature form of cristobalite and, in zirconia grade fibres, the high-temperature, tetragonal form of zirconia as well. Further heating changed surface structure and led to zircon production in the zirconia fibres. Heating reduced the affinity of the fibres for the surface of V79-4 cells and lowered fibre toxicity toward these cells and towards macrophage-like cells. These changes in toxicity were not due to a reduction in the fibrous nature of the materials although they did become more brittle and powders prepared from them contained more isometric particles than those from as-manufactured materials. This suggests that the devitrification occurring during the use of these materials in high-temperature environments will not necessarily enhance their adverse biological activities despite the production of one phase of crystalline silica.