Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency,Bipolar Radiofrequency,and Microwave,Using Ex Vivo Calf Liver Model

Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink.     

Conversion from mycophenolate mofetil to enteric-coated mycophenolate sodium in liver transplant patients presenting gastrointestinal disorders: a pilot study.

Gastrointestinal (GI) disorders are one of the main adverse events in patients treated by mycophenolic acid (MPA). The aim of this prospective study was to evaluate the effect of conversion from mycophenolate mofetil (MMF) to enteric-coated mycophenolate sodium (EC-MPS) in liver transplant patients presenting GI side-effects Since January 2003, stable liver transplant patients receiving MMF and presenting GI disorders, without evidence of other origin than MMF were enrolled. Conversion was performed without a washout period at an equimolar daily dosage. Thirty-six patients were included after a median delay of 45 months after liver transplantation (LT) (16 women and 20 men, median age of 47 years). Diarrhoea was the main clinical symptom (n = 28, 77.7%). At the time of inclusion, patients were treated with MMF since 18 months (range 3-28) and GI disorders were known for 9 months (range 3-12). After a median follow-up of 12 months after conversion, GI disorders were resolved in 20 patients (55%), improved in 6 patients (17%) and not modified or worsened in 10 patients (28%). Our results strongly suggest that conversion from MMF to EC-MPS in liver transplant patients can improve gastrointestinal disorders in a majority of the patients, and therefore might be considered as the best therapeutic option.     

Leptin, lipid and lipid metabolism-related hormones in chronic renal failure in Arabia

SUMMARY: In patients with chronic renal failure (CRF), hyperleptinaemia has been widely reported, but the exact mechanisms leading to elevated leptin levels are unclear. Impaired renal clearance of leptin and the influence of other hormones may be important. In this study, we measured serum leptin levels in 150 patients on haemodialysis, peritoneal dialysis or in the predialysis phase of CRF. Furthermore, we measured plasma levels of insulin, growth hormone (GH) and insulin-like growth factor 1 (IGF-1), as well as plasma levels of triacylglycerols and total low density lipoprotein (LDL)- and high density lipoprotein (HDL)-cholesterol. We observed significantly elevated levels of leptin, particularly in female patients, and leptin was shown to correlate significantly with insulin, total and LDL-cholesterol and log triacylglycerols. Leptin was inversely correlated with GH concentrations, but was not correlated with IGF-1 levels. Despite the multiple correlations established between leptin levels and other variables, only hyperinsulinaemia in CRF seems to be important as a determinator of leptin levels.     

Regression of lymphomatous skin deposits in a chronic lymphocytic leukemia patient treated with the Toll-like receptor-7/8 agonist, imiquimod.

The identification of clinically relevant, active immunomodulatory agents is important for developing immunotherapeutic approaches to chronic lymphocytic leukemia (CLL) and other B-cell lymphomas that are not curable with conventional chemotherapy. In this investigation, the imidazoquinoline Toll-like receptor (TLR)-7/8 agonist, imiquimod, was found to mediate the clearance of a lymphomatous skin lesion in a CLL patient. Imidazoquinolines also activated TLR-7/8 signaling pathways, resulting in increased expression of costimulatory molecules on circulating tumor cells. These observations extend the therapeutic spectrum of imiquimod to cutaneous B-cell lymphomas and suggest the use of TLR-7/8 agonists in CLL immunotherapy.     

Cerebral blood flow changes in normal aging: Spect measurements

Global and regional cerebral blood flow (CBF) were evaluated with single photon emission computerized tomography (SPECT) utilizing both ¹³³Xenon (¹³³Xe) (47 subjects, 47–82 years old) and ⁹⁹Tc-hexamethylpropyleneamine oxime (⁹⁹Tc-HMPAO) (27 subjects, 47–80 years old). The ¹³³Xe results showed: among total subjects, no age-related decline in global CBF, but a significant regional decline in the occipital lobe (p < 0.05); among men, significant age-related declines in global, frontal, temporal, occipital and right hemisphere CBF (all p < 0.05); among women, no age-related decline in global or regional CBF. The ⁹⁹Tc-HMPAO results showed no age-related decline in either global or regional perfusion among total subjects, men or women. These results suggest that age-related global and regional (including frontal lobe) CBF declines do not occur in healthy control subjects after the age of 45 years. However, gender differences in age-related CBF changes warrant further study.     

Clinical epidemiology and survival of progressive multifocal leukoencephalopathy in the era of highly active antiretroviral therapy: Data from the Italian Registry Investigative Neuro AIDS (IRINA)

Human immunodeficiency virus (HIV)-associated progressive multifocal leukoencephalopathy (PML) remains a relevant clinical problem even in the era of highly active antiretroviral therapy (HAART). Aims of the study were to analyze clinical and treatment-related features and the survival probability of PML patients observed within the Italian Registry Investigative Neuro AIDS (IRINA) during a 29-month period of HAART. Intravenous drug use, the presence of focal signs, and the involvement of white matter at neuroradiology increased the risk of having PML. A reduced probability of PML was observed when meningeal signs were reported. Patients starting HAART at PML diagnosis and previously naïve for antiretrovirals showed significantly higher 1-year probability of survival (.58), compared to those continuing HAART (.24), or never receiving HAART (.00). Higher CD4 cell count were associated with a higher survival probability (.45). At multivariate analysis, a younger age, higher CD4, starting HAART at PML diagnosis, the absence of previous acquired immunodeficiency syndrome (AIDS)-defining events, and the absence of a severe neurologic impairment were all associated with a reduced hazard of death. The use of cidofovir showed a trend towards a reduced risk of death.     

Adverse outcomes of planned and unplanned pregnancies among users of natural family planning: a prospective study.

OBJECTIVES: The purpose of this study was to determine prospectively whether unplanned pregnancies are associated with adverse pregnancy outcomes among users of natural family planning. METHODS: Women who became pregnant while using natural family planning were identified in five centers worldwide: there were 373 unplanned and 367 planned pregnancies in this cohort. The subjects were followed up at 16 and 32 weeks' gestation and after delivery. The risks of spontaneous abortion, low birth-weight, and preterm birth were estimated after adjustment by logistic regression. RESULTS: The women with unplanned pregnancies were more likely to be at the extremes of age, to report more medical problems before and during the index pregnancy, and to seek antenatal care later in gestation than the women with planned pregnancies. However, women with planned pregnancies reported a higher rate of spontaneous abortion in previous pregnancies (28.8%) than did women with unplanned pregnancies (12.9%). There were no significant differences in the rates of spontaneous abortion, low birthweight, or preterm birth between the two groups. CONCLUSIONS: No increased risk of adverse pregnancy outcomes was observed among women who experienced an unplanned pregnancy while using natural family planning.     

Review of imaging techniques for the diagnosis of breast cancer: a new role of prone scintimammography using technetium-99m sestamibi

Imaging techniques currently used for the diagnosis of breast cancer are reviewed and compared. Besides mammography, magnetic resonance imaging, positron emission tomography, and thallium-201 scintimammography, a new role of technetium-99m sestamibi scintimammography is discussed. It is concluded that while mammography remains the procedure of choice in screening asymptomatic women for breast cancer, other imaging methods play an important role in detecting malignancies in symptomatic patients.^99mTc-sestamibi scintimammography has high sensitivity and improves the specificity of conventional mammography for the detection of breast cancer; with this technique, prone imaging is preferable to supine imaging.^99mTc-sestamibi scintimammography thus deserves further study as a screening technique.