HIV protease inhibitors and dyslipidemia

Highly active antiretroviral therapy (HAART) significantly prolongs the lives of HIV-infected patients. Current regimens may consist of a protease inhibitor (PI) combined with at least two or more other antiretroviral drugs. PI administration has been shown to be associated with alterations in plasma lipids (i.e. prompt and sustained increases in total cholesterol, low-density lipoprotein cholesterol, and triglycerides) and insulin levels that place PI-treated patients at risk for coronary heart disease (CHD). Because PI-associated dyslipidemia is generally asymptomatic and occurs in patients who are often younger than those traditionally at risk for CHD, the need for primary prevention of acute coronary events in these patients is often unappreciated. Statins form a significant component of pharmacotherapy for PI-associated dyslipidemia. However, because PIs and all statins except pravastatin are metabolized by the cytochrome P450 (CYP) system, co-administration of these agents produces a significant risk of drug interactions and statin-induced hepatotoxicity and myopathy. This risk can be greatly reduced by administering a statin not metabolized by CYP. The need for lipid reduction therapy may be minimized with the use of new PIs that are comparable in efficacy to current PIs but do not negatively affect lipid levels.     

Intravenous treatment with liposome-encapsulated dichloromethylene bisphosphonate (C12MBP)suppresses nitric oxide production and reduces genetic resistance to Marek's disease

In this study the functional effectiveness of in vivo macrophage depletion using liposome-encapsulateddichloromethylene bisphosphonate (C12MBP) was examined in the chicken. The main target organs forsystemic liposome-encapsulated C12MBP treatment are the spleen and the liver. Intravenous treatment withC12MBP of B²¹/B²¹ chickens, genetically resistant to Marek's disease (MD), before challenge with the very virulent strain RB-lB, increased viral load in the blood and spleen after the first week and up to 6 weeks postinfection. In addition, C12MBP treatment dramatically increased tumour incidence and tumour load, especially in the spleens and livers of sick animals, but without affecting MD-specific mortality of B²¹/B²¹ cickens infected with RB-1B at 12 days of age. Nitric oxide (NO) is an important effector of the macrophage and has antiviral and antitumoural properties. NO has been shown to be one of the mechanisms triggered in resistance to Marek's disease. Intravenous treatment with Cl2MBP before infection with RB-1B induced a long-lasting decrease in numbers of macrophages and reduction in splenic inducible NO production associated with an absence of nitrate induction in the serum (up to 6 weeks pi). These results do not identify macrophage and NO production as major effector components in genetic resistance to Marek's disease, but underline their roles in limiting viraemia and tumour development in organs such as the spleen and the liver.     

Incorporating an improved dose-calculation algorithm in conformal radiotherapy of lung cancer: re-evaluation of dose in normal lung tissue.

BACKGROUND AND PURPOSE: The low density of lung tissue causes a reduced attenuation of photons and an increased range of secondary electrons, which is inaccurately predicted by the algorithms incorporated in some commonly available treatment planning systems (TPSs). This study evaluates the differences in dose in normal lung tissue computed using a simple and a more correct algorithm. We also studied the consequences of these differences on the dose-effect relations for radiation-induced lung injury. MATERIALS AND METHODS: The treatment plans of 68 lung cancer patients initially produced in a TPS using a calculation model that incorporates the equivalent-path length (EPL) inhomogeneity-correction algorithm, were recalculated in a TPS with the convolution-superposition (CS) algorithm. The higher accuracy of the CS algorithm is well-established. Dose distributions in lung were compared using isodoses, dose-volume histograms (DVHs), the mean lung dose (MLD) and the percentage of lung receiving >20 Gy (V20). Published dose-effect relations for local perfusion changes and radiation pneumonitis were re-evaluated. RESULTS: Evaluation of isodoses showed a consistent overestimation of the dose at the lung/tumor boundary by the EPL algorithm of about 10%. This overprediction of dose was also reflected in a consistent shift of the EPL DVHs for the lungs towards higher doses. The MLD, as determined by the EPL and CS algorithm, differed on average by 17+/-4.5% (+/-1SD). For V20, the average difference was 12+/-5.7% (+/-1SD). For both parameters, a strong correlation was found between the EPL and CS algorithms yielding a straightforward conversion procedure. Re-evaluation of the dose-effect relations showed that lung complications occur at a 12-14% lower dose. The values of the TD(50) parameter for local perfusion reduction and radiation pneumonitis changed from 60.5 and 34.1 Gy to 51.1 and 29.2 Gy, respectively. CONCLUSIONS: A simple tissue inhomogeneity-correction algorithm like the EPL overestimates the dose to normal lung tissue. Dosimetric parameters for lung injury (e.g. MLD, V20) computed using both algorithms are strongly correlated making an easy conversion feasible. Dose-effect relations should be refitted when more accurate dose data is available.     

Medical decision making for older patients during multidisciplinary oncology team meetings

Objectives

Multidisciplinary team meetings aim to facilitate efficient and accurate communication surrounding the complex process of treatment decision making for older patients with cancer. This process is even more complicated for older (≥70?years) patients as the lack of empirical evidence on treatment regimens in patients with age-related problems such as comorbidity and polypharmacy, necessitates a patient-centred approach.This study investigates the decision making process for older patients with cancer during multidisciplinary team meetings and the extent to which geriatric evaluation and geriatric expertise contribute to this process.

Clínicas de anticoagulação,situação actual e perspectivas futuras

There are several modalities to monitor oral anticoagulant therapy, namely: monitoring by a secondary care specialist in the hospital setting; monitoring by the general practitioner/ family doctor in the primary care setting; monitoring by private laboratories of clinical analysis; self-monitoring with point-of-care devices. In Portugal, the most frequent modality is still the hospital monitoring/anticoagulation clinics, although monitoring in the primary care/routine medical care setting has began to be implemented in some areas of the country since five years ago. Anticoagulation clinics are still actually the organizations that optimize better the clinical and laboratorial follow up of the patients anticoagulated with warfarin. In 2011, anticoagulation control quality was evaluated, in the setting of an anticoagulation clinic (Santo António Hospital, Porto Hospital Center) by determining the proportion of INRs within the therapeutic range. The evaluation focused ambulatory patients, during a period of two months, corresponding to 1067 controls from 687 patients (mean age: 69 ± 13 years; 54%, n = 567, female gender). 71% of controls (n = 756) were within the therapeutic range. 27% of controls were outside the therapeutic range, after exclusion of patients with programmed surgery or invasive proceedings. 13.8% of controls were below the therapeutic range and 8.6% (n = 92) of the latter had INR ≤ 1.5. Above therapeutic range were 13.2% (n = 139), from which 4.4% (n = 46) had an INR between 5–8 and 0.3% (n = 4) an INR ≥ 8. The group of primary care Health Centers (Portuguese acronym ACES) of the Baixo Tâmega region conducted, also in 2011, an evaluation of the anticoagulant control quality, by determining the proportion of INRs within the therapeutic range. The results were similar to those found in the anticoagulation clinic of the Hospital de Santo António which shows that the quality of monitoring in the primary care setting can have the same quality of the anticoagulation clinics monitoring. The introduction of the new oral anticoagulants, that don’t require laboratorial monitoring constitutes a challenge. In Portugal, there is no experience yet to respond to the question if, in this new context, the anticoagulation clinics will be fundamental for the registration of patients, the evaluation of the hemorrhagic risk, the clinical follow up or the evaluation of the adherence to therapy.     

Adrenal involvement in the antiphospholipid syndrome: clinical and immunologic characteristics of 86 patients

To describe the clinical and immunologic characteristics of patients with adrenal involvement and antiphospholipid syndrome (APS), we conducted a computer-assisted (PubMed) search of the literature to identify all cases of primary adrenal insufficiency associated with antiphospholipid antibodies published in English, French, and Spanish from 1983 (when APS was first defined) through March 2002. We reviewed 86 patients (80 from the literature plus 6 from our cohort); 55% were male, and the mean age at presentation was 43 +/- 16 years. Sixty-one (71%) patients had primary APS, and 14 (16%) had systemic lupus erythematosus. In 31 (36%) patients, adrenal insufficiency was the first clinical manifestation of APS. Abdominal pain was present in 55% of patients, followed by hypotension (54%), fever (40%), nausea or vomiting (31%), weakness or fatigue (31%), and lethargy or altered mental status (19%). The main finding in imaging techniques was compatible with adrenal hemorrhage (59%) and in histopathologic study was a hemorrhagic infarction with vessel thrombosis (55%). Lupus anticoagulant was detected in 97% of patients and the anticardiolipin antibodies titer was positive in 93% of patients. Most patients (95%) were positive for the IgG isotype of anticardiolipin antibodies, whereas 40% were positive for the IgM isotype. Baseline cortisol levels were decreased in 98% of patients, ACTH hormone levels were increased in 96% of patients, and the cosyntropin stimulation test was positive in 100% of patients tested. Steroid replacement therapy was the most frequent treatment (84%), followed by anticoagulation (52%) and aspirin (6%). Thirty-two of 35 (91%) patients with prolonged anticoagulant therapy were in good health with a mean follow-up of 25 months, whereas 25 of the 69 (36%) patients with outcome data available had died. The results of the present review stress the clinical importance of systematic screening for lupus anticoagulant and anticardiolipin antibodies in all cases of adrenal hemorrhage or infarction. An initial screening for hypoadrenalism is mandatory in any antiphospholipid antibody-positive patient who complains of abdominal pain and undue weakness or asthenia.