An MRI-compatible robotic system with hybrid tracking for MRI-guided prostate intervention

This paper reports the development, evaluation, and first clinical trials of the access to the prostate tissue (APT) II system-a scanner independent system for magnetic resonance imaging (MRI)-guided transrectal prostate interventions. The system utilizes novel manipulator mechanics employing a steerable needle channel and a novel six degree-of-freedom hybrid tracking method, comprising passive fiducial tracking for initial registration and subsequent incremental motion measurements. Targeting accuracy of the system in prostate phantom experiments and two clinical human-subject procedures is shown to compare favorably with existing systems using passive and active tracking methods. The portable design of the APT II system, using only standard MRI image sequences and minimal custom scanner interfacing, allows the system to be easily used on different MRI scanners.     

Refractory effect and alloimmunization after transfusion of thrombocytes]

The authors discuss possible ways for prevention of alloimmunization with HLA-antigen in acute leukemia patients after platelet transfusions. Prevention or delay of HLA-alloimmunization is possible when platelets of single random donor are used instead of pooled random donor platelets for transfusions. The effect of leucocyte removal from platelet concentrates and ultraviolet irradiation of platelet concentrates under conditions of blood bank on alloimmunization and refractoriness incidence has been considered.     

Role of tyrosine kinase and phosphotyrosine phosphatase in growth of the intestinal crypt cell (IEC-6) line

Antibodies to hepatitis C virus (HCV) were measured in 1,580 Ethiopian subjects representing urban and rural populations. Sera found positive by a repeated second generation enzyme immunoassay (EIA) were subjected to three additional confirmatory tests. The overall confirmed seroprevalence was 2.0%. Less than 1% were confirmed to be seropositive in rural communities, with 1.4% positive among blood donors, 1.6% positive among patients with dermatologic disorders, 3.6% among leprosy patients, and 6.0% among patients attending a University Hospital clinic for neurologic disorders. The patients in the groups with leprosy and neurologic disorders have most likely been in ill health for many years and have sought relief by traditional healers or treatment at poorly equipped clinics. This group of patients demonstrated a high prevalence of antibodies to HCV. In Ethiopia, especially in small clinics, there is a shortage of syringes and needles and they have to be reused many times often with inadequate sterilization. Therefore, these syringes and needles may be contaminated, thus being a risk factor for HCV and HIV infection.     

Expression of the antisense cDNA for protein kinase C alpha attenuates resistance in doxorubicin-resistant MCF-7 breast carcinoma cells

Multidrug resistance is functionally associated with the expression of a plasma membrane energy-dependent drug efflux pump termed P-glycoprotein, the product of the mdr1 gene. Transfection of P-glycoprotein-expressing doxorubicin-resistant MCF-7 cells with an expression vector containing the cDNA for protein kinase C alpha in the antisense orientation reduces protein kinase C alpha levels and decreases total protein kinase C activity by 75%. This is accompanied by reduced phosphorylation of P-glycoprotein, a 2-fold increase in drug retention, and a 3-fold increase in doxorubicin cytotoxicity. These results provide further evidence that protein kinase C alpha can positively regulate multidrug resistance in MCF-7 cells through posttranslational phosphorylation of P-glycoprotein.     

The effects of a converting enzyme inhibitor (captopril) and angiotensin II on fetal renal function

1. Renal function was studied in chronically catheterized fetal sheep (119-128 days gestation), before and during treatment of the ewe with the angiotensin converting enzyme (ACE) inhibitor, captopril, which crosses the placenta and blocks the fetal renin angiotensin system. 2. An i.v. dose of 15 mg (about 319 micrograms kg-1) of captopril to salt-replete ewes followed by an infusion to the ewe of 6 mg h-1 (about 128 micrograms kg-1 h-1) caused a fall in fetal arterial pressure (P < 0.01), and a rise in fetal renal blood flow (RBF) from 67.9 +/- 5.6 to 84.9 +/- 8.3 ml min-1 (mean +/- s.e. mean) (P < 0.05). Renal vascular resistance and glomerular filtration rate (GFR) fell (P < 0.01); fetal urine flow (P < 0.01); fetal urine flow (P < 0.01) and sodium excretion declined (P < 0.05). 3. Ewes were treated for the next 2 days with 15 mg captopril twice daily. On the 4th day, 15 mg was given to the ewe and fetal renal function studied for 2 h during the infusion of captopril (6 mg h-1) to the ewe. Of the 9 surviving fetuses, 3 were anuric and 3 had low urine flow rates. When 6 micrograms kg-1 h-1 of angiotensin II was infused directly into the fetus RBF fell from 69 +/- 10.1 ml min-1 to 31 +/- 13.9 ml min-1, GFR rose (P < 0.05) and urine flow (P < 0.01) and sodium excretion increased in all fetuses. 4. It is concluded that the small fall in fetal arterial pressure partly contributed to the fall in fetal GFR but in addition, efferent arteriolar tone fell so that the filtration pressure fell further. Thus maintenance of fetal renal function depends on the integrity of the fetal renin angiotensin system. These findings explain why use of ACE inhibitors in human pregnancy is associated with neonatal anuria.     

Transesophageal echocardiographic localization of an aortic valve papillary fibroelastoma during routine coronary artery bypass surgery

Papillary fibroelastomas are rare, primary cardiac tumors most often diagnosed incidentally at autopsy. These tumors have been associated with embolism, neurologic injury, coronary ischemia and sudden death. We report a case of clinical detection of an asymptomatic aortic valve papillary fibroelastoma by transesophageal echocardiography. The mass was an incidental finding during routine coronary artery bypass surgery. This finding dictated a change in the operative approach to include resection of the aortic valve mass in addition to coronary revascularization.     

Epidemiology of potential association between L-tryptophan ingestion and eosinophilia-myalgia syndrome

This article examines the methodology of the epidemiological studies of the association between L-tryptophan and eosinophilia-myalgia syndrome (EMS) and evaluates the validity of the conclusions from these studies. In the initial case-control studies of L-tryptophantryptophan and EMS there were a variety of methodological problems, including different sources and different exclusion criteria for cases and controls, which could have resulted in selection bias, as well as problems with information bias and confounding. The studies of manufacturer and brand also had similar potential for bias. The L-tryptophan-EMS association is based on two small studies that had important methodological inadequacies. Subsequent studies of brand of L-tryptophan also contained errors in design, which may have produced biased results and call the conclusions into question. The cause of eosinophilia-myalgia syndrome remains unknown.