Day: 01/24/2011

Contagious Cancer

Posted by

0


Although cancer can on occasion be caused by infectious agents such as specific bacteria, parasites, and viruses, it is not generally considered a transmissible disease. In rare circumstances, however, direct communication from one host to another has been documented. The Tasmanian devil is now threatened with extinction in the wild because of a fatal transmissible cancer, devil facial tumor disease (DFTD). Another example is canine transmissible venereal tumor (CTVT or Sticker’s sarcoma) in dogs. There is a vast difference in prognosis between these two conditions. DFTD is often fatal within 6 months, whereas most cases of CTVT are eventually rejected by the host dog, who then is conferred lifelong immunity. In man, only scattered case reports exist about such communicable cancers, most often in the setting of organ or hematopoietic stem cell transplants and cancers arising during pregnancy that are transmitted to the fetus. In about one third of cases, transplant recipients develop cancers from donor organs from individuals who were found to harbor malignancies after the transplantation. The fact that two thirds of the time cancer does not develop, along with the fact that cancer very rarely is transmitted from person to person, supports the notion that natural immunity prevents such cancers from taking hold in man. These observations might hold invaluable clues to the immunobiology and possible immunotherapy of cancer.

source: the oncologist

Regulation of cancer cell metabolism

Posted by

0


Interest in the topic of tumour metabolism has waxed and waned over the past century of cancer research. The early observations of Warburg and his contemporaries established that there are fundamental differences in the central metabolic pathways operating in malignant tissue. However, the initial hypotheses that were based on these observations proved inadequate to explain tumorigenesis, and the oncogene revolution pushed tumour metabolism to the margins of cancer research. In recent years, interest has been renewed as it has become clear that many of the signalling pathways that are affected by genetic mutations and the tumour microenvironment have a profound effect on core metabolism, making this topic once again one of the most intense areas of research in cancer biology.

Genomic instability in cancer

Posted by

0


Genomic instability is often associated with cancer and can be indicative of a poor prognosis for some types of cancer. But, is genomic instability a consequence of tumour progression or an active process that drives tumour evolution? The answer to this question has still not been entirely resolved. Many new findings have highlighted certain DNA repair pathways and cell cycle control processes that have important consequences for genomic stability and tumour cell biology. Indeed, there are numerous efforts to manipulate the DNA damage responses to selectively induce tumour cell death through catastrophic genomic instability, and some are already showing promise. Of course, radiotherapy and other existing chemotherapeutic agents should not be overlooked as therapeutic strategies by which DNA damage induces tumour cell death and there are various efforts to improve the response to radiotherapy and to understand responses (and resistance) to current cytotoxic chemotherapeutics. This series takes a look at the progress made in this field and the questions that remain about the role of genomic instability in cancer.

source: nature

Hypertension After Kidney Transplant

Posted by

0


Hypertension in kidney transplant recipients is a major “traditional” risk factor for atherosclerotic cardiovascular disease. Importantly, atherosclerotic cardiovascular disease is the leading cause of premature death and a major factor in death-censored graft failure in transplant recipients. The blood pressure achieved after transplant is related inversely to postoperative glomerular filtration rate (GFR), with many patients experiencing a significant improvement in blood pressure control with fewer medications within months of surgery. However, the benefits of improved GFR and fluid status may be affected by the immunosuppression regimen. Immunosuppressive agents affect hypertension through a variety of mechanisms, including catechol- and endothelin-induced vasoconstriction, abrogation of nitric oxide–induced vasodilatation, and sodium retention. Most notable is the role of calcineurin inhibitors in promoting hypertension, cyclosporine more so than tacrolimus. Additionally, the combination of calcineurin- and mammalian target of rapamycin (mTOR)-inhibitor therapy is synergistically nephrotoxic and promotes hypertension, whereas steroid withdrawal and minimization strategies seem to have little or no impact on hypertension. Other important causes of hypertension after transplant, beyond a progressive decrease in GFR, include transplant renal artery stenosis and sequelae of antibody-mediated rejection. Calcium channel blockers may be the most useful medication for mitigating calcineurin inhibitor–induced vasoconstriction, and use of such agents may be associated with improvements in GFR. Use of inhibitors of the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, remains an attractive strategy for many transplant recipients, although some recipients may have significant adverse effects associated with these medications, including decreased GFR, hyperkalemia, and anemia. In conclusion, hypertension control affects both patient and long-term transplant survival, and its best management requires careful analysis of causes and close monitoring of therapies.

source: American journal of hypertension

Use of lead shielding on pregnant patients undergoing CT scans

Posted by

0


An online survey has been used to assess the use of abdominal lead shielding on pregnant patients undergoing CT scans. The aim of the study was to identify potential geographical variations in the use of such shielding as well as the opinions of the users in terms of the weight, manoeuvrability and ergonomics of the lead shields.

Materials and methods

The online questionnaire was distributed to CT Radiographers in the UK, Europe, North America and Australia and responses were gathered electronically over a six month period. All completed responses were downloaded and subsequently analysed for each geographical region.

Results

In total, 390 completed questionnaires were received with over 100 from each of the UK, North America and Australia. The use of lead shielding was found to vary significantly across the globe with the highest usage in North America (94.5%) and the lowest usage in Europe (46.3%). Approximately 20% of all respondents said that they experienced occupationally related back pain and 25% of all respondents said that patients complained about the weight of the shielding.

Conclusion

Significant geographical variations in both the use of lead shielding for foetal radiation protection and the users’ opinions of the shielding devices that are used have been identified and it has become clear that existing shielding solutions are not optimised for this task.

FDA Approves New Treatment for Major Depression

Posted by

0


Vilazodone hydrochloride, a combined selective serotonin reuptake inhibitor and serotonin 1A receptor partial agonist, has been approved by the FDA to treat major depressive disorder in adults.

According to the manufacturer, vilazodone (marketed as Viibryd) did not affect sexual function or cause significant weight gain during clinical trials, side effects that are commonly seen with other antidepressants. Adverse reactions included diarrhea, insomnia, nausea, and vomiting. Previous trials indicate that the efficacy of this drug is comparable to that of other approved antidepressants.

Like all antidepressants, the drug will carry a boxed warning about the increased risks for suicidality during the early phase of treatment in patients aged 18 to 24. Additionally, patients will receive a medication guide when filling their prescriptions.

The tablets will be available in 10, 20, and 40 mg doses.

Source:FDA