Expression of constitutively activated human c-Kit in myb transformed early myeloid cells leads to factor independence, histiocytic differentiation, and tumorigenicity

The cDNAs encoding wild type (WT) human receptor tyrosine kinase c-Kit and a constitutively activated mutant, V816Kit, were introduced into granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent early murine hemopoietic cells, which had been transformed with activated Myb, WTKit cells were able to grow in the presence of the human ligand for Kit, stem cell factor (SCF), but displayed reduced growth and clonogenic potential in either SCF or GM-CSF compared with the parental cells in GM-CSF. In contrast, V816Kit cells grew without factor at a higher rate than the parental cells in GM-CSF and displayed increased clonogenicity. Dissection of the growth characteristics in liquid culture showed that in the presence of appropriate factors, the different populations had similar proliferation rates, but that V816Kit profoundly increased cell survival compared with WTKit or parental cells, This suggests that the signals transduced by WTKit activated with SCF, and by V816Kit, were not identical. Also, WTKit and V816Kit-expressing cells both varied from the early myeloid progenitor phenotype of the parental cells and gave rise to a small number of large to giant adherent cells that expressed macrophage (alpha-naphthyl acetate) esterase and neutrophil (naphtol-AS-D-chloroacetate) esterase, were highly phagocytic and phenotypically resembled histiocytes. Thus, WTKit activated by SCF and V816Kit were able to induce differentiation in a proportion of Myb-transformed myeloid cells. The factor independent V816Kit cells, unlike the parental and WTKit expressing cells, were shown to produce tumors of highly mitotic, invasive cells at various stages of differentiation in syngeneic mice. These results imply that constitutively activated Kit can promote the development of differentiated myeloid tumors and that its oncogenic effects are not restricted to lineages (mast cell and B-cell acute lymphoblastic leukemia), which have been reported previously. Furthermore, the mixed populations of cells in culture and in the tumors phenotypically resembled the leukemic cells from patients with monocytic leukemia with histiocytic differentiation (acute myeloid leukemia-M5c), a newly proposed subtype of myeloid leukemia. (C) 1997 by The American Society of Hematology.

Chronic American trypanosomiasis: parasite persistence in endomyocardial biopsies is associated with high-grade myocarditis

Myocyte diameter, fractional area of collagen, intensity of myocarditis and parasite persistence (explored by immunohistochemistry and PCR) were evaluated in serial sections of endomyocardial biopsies from 29 outpatients with chronic chagasic cardiopathy. The patients, 25 males and four females with a mean (S.D.) age of 43 (9) years, were subsequently followed up for 3-2861 days (median=369 days). During this follow-up, 16 (55%) of the patients died. The biopsies revealed myocarditis in 25 (86%) of the patients and high-grade myocarditis in 14 (56%). Although immunohistochemistry failed to demonstrate Trypanosoma cruzi antigens in any of the samples, five (33%) of the 15 biopsies successfully tested in the PCR-based assay for T. cruzi DNA were found positive, indicating parasite persistence. There was a significant positive association between myocardial parasite persistence and high-grade myocarditis (P= 0.014); five (71%,) of the seven endomyocardial biopsies with high-grade myocarditis that were successfully tested in the PCR assays showed persistent T. cruzi DNA. The survival time of the patients was not, however, found to be significantly associated with myocardial parasite persistence, any of the morphometric measurements taken, or the presence or intensity of myocarditis.

Type of Alcoholic Beverage and Risk of Head and Neck Cancer-025EFA Pooled Analysis Within the INHANCE Consortium

The authors pooled data from 15 case-control studies of head and neck cancer (9,107 cases, 14,219 controls) to investigate the independent associations with consumption of beer, wine, and liquor. In particular, they calculated associations with different measures of beverage consumption separately for subjects who drank beer only (858 cases, 986 controls), for liquor-only drinkers (499 cases, 527 controls), and for wine-only drinkers (1,021 cases, 2,460 controls), with alcohol never drinkers (1,124 cases, 3,487 controls) used as a common reference group. The authors observed similar associations with ethanol-standardized consumption frequency for beer-only drinkers (odds ratios (ORs) = 1.6, 1.9, 2.2, and 5.4 for <= 5, 6-15, 16-30, and > 30 drinks per week, respectively; P(trend) < 0.0001) and liquor-only drinkers (ORs = 1.6, 1.5, 2.3, and 3.6; P < 0.0001). Among wine-only drinkers, the odds ratios for moderate levels of consumption frequency approached the null, whereas those for higher consumption levels were comparable to those of drinkers of other beverage types (ORs = 1.1, 1.2, 1.9, and 6.3; P < 0.0001). Study findings suggest that the relative risks of head and neck cancer for beer and liquor are comparable. The authors observed weaker associations with moderate wine consumption, although they cannot rule out confounding from diet and other lifestyle factors as an explanation for this finding. Given the presence of heterogeneity in study-specific results, their findings should be interpreted with caution.

Incidence and risk factors for agranulocytosis in Latin American countries - the Latin study

Purpose LATIN is a multinational case-control study designed to identify risk factors for agranulocytosis and to estimate the incidence rate of the disease in some Latin American countries. Methods Each study site in Brazil, Argentina and Mexico conducted an active search of agranulocytosis patients in hematology clinics and looked for possible associations with drug use. Results The overall incidence rate was 0.38 cases per 1 million inhabitant-years. Agranulocytosis patients more often took medications already associated with agranulocytosis than controls (p=0.01), mainly methimazole (OR 44.2, 95% CI 6.8 to infinity). The population attributable risk percentage (etiologic fraction) was 56%. The use of nutrient supplements was more frequent among patients than controls (p=0.03). Conclusions Agranulocytosis seems to be very rare in Latin America. The lower than expected number of cases identified during the study period precluded estimation of the risk associated to individual drugs, with the exception of methimazol. However, this is the longest series of agranulocytosis cases ever gathered in Latin America, and information on drug exposures was collected prospectively. The conclusion is that drug-induced agranulocytosis does not seem to be a major public health problem in the study regions.

Time- and Fluid-Sensitive Resuscitation for Hemodynamic Support of Children in Septic Shock Barriers to the Implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support Guidelines in a Pediatric Intensive Care Unit in a Developing World

Objectives: To analyze mortality rates of children with severe sepsis and septic shock in relation to time-sensitive fluid resuscitation and treatments received and to define barriers to the implementation of the American College of Critical Care Medicine/Pediatric Advanced Life Support guidelines in a pediatric intensive care unit in a developing country. Methods: Retrospective chart review and prospective analysis of septic shock treatment in a pediatric intensive care unit of a tertiary care teaching hospital. Ninety patients with severe sepsis or septic shock admitted between July 2002 and June 2003 were included in this study. Results: Of the 90 patients, 83% had septic shock and 17% had severe sepsis; 80 patients had preexisting severe chronic diseases. Patients with septic shock who received less than a 20-mL/kg dose of resuscitation fluid in the first hour of treatment had a mortality rate of 73%, whereas patients who received more than a 40-mL/kg dose in the first hour of treatment had a mortality rate of 33% (P < 0.05.) Patients treated less than 30 minutes after diagnosis of severe sepsis and septic shock had a significantly lower mortality rate (40%) than patients treated more than 60 Minutes after diagnosis (P < 0.05). Controlling for the risk of mortality, early fluid resuscitation was associated with a 3-fold reduction in the odds of death (odds ratio, 0.33; 95% confidence interval, 0.13-0.85). The most important barriers to achieve adequate severe sepsis and septic shock treatment were lack of adequate vascular access, lack of recognition of early shock, shortage of health care providers, and nonuse of goals and treatment protocols. Conclusions: The mortality rate was higher for children older than years, for those who received less than 40 mL/kg in the first hour, and for those whose treatment was not initiated in the first 30 Minutes after the diagnosis of septic shock. The acknowledgment of existing barriers to a timely fluid administration and the establishment of objectives to overcome these barriers may lead to a more successful implementation of the American College of Critical Care Medicine guidelines and reduced mortality rates for children with septic shock in the developing world.

In vitro infectivity of species of Leishmania (Viannia) responsible for American cutaneous leishmaniasis

There is little available information regarding the infectivity of New World Leishmania species, particularly those from the Amazonian Brazil, where there are six species of the subgenus Viannia causing American cutaneous leishmaniasis (ACL). The aim of this study was to compare, in vitro, the potential infectivity of the following Leishmania (Viannia) spp.: L. (V.) braziliensis from localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL) patients, L. (V.) guyanensis, L. (V.) shawi, L. (V.) lainsoni and L. (V.) naiffi from LCL patients only, in cultured BALB/c mice peritoneal macrophage, as well as the production of NO by the infected cells. The infectivity of parasites was expressed by the infection index and, the nitric oxide (NO) production in the macrophage culture supernatant was measured by the Griess method. It was found that L. (V.) braziliensis from MCL, the more severe form of disease, showed the highest (p <= 0.05) infection index (397), as well as the lowest NO production (2.15 mu M) compared with those of other species. In contrast, L. (V.) naiffi which is less pathogenic for the human showed the lowest infection index (301) and the highest NO production (4.11 mu M). These results demonstrated a negative correlation between the infectivity and the ability of these parasites to escape from the microbicidal activity of the host cell.

Independent component analysis applied to raman spectra for classification of in vitro human coronary arteries

Optical diagnostic methods, such as near-infrared Raman spectroscopy allow quantification and evaluation of human affecting diseases, which could be useful in identifying and diagnosing atherosclerosis in coronary arteries. The goal of the present work is to apply Independent Component Analysis (ICA) for data reduction and feature extraction of Raman spectra and to perform the Mahalanobis distance for group classification according to histopathology, obtaining feasible diagnostic information to detect atheromatous plaque. An 830nm Ti:sapphire laser pumped by an argon laser provides near-infrared excitation. A spectrograph disperses light scattered from arterial tissues over a liquid-nitrogen cooled CCD to detect the Raman spectra. A total of 111 spectra from arterial fragments were utilized.

Factor XIIIa plus Dermal Dendrocyte Parasitism in American Tegumentary Leishmaniasis Skin Lesions

Dendritic cells belong to a family of antigen-presenting cells that are localized at the entry sites, such as skin and mucosa. Dendritic cells are related to immune surveillance function. The role of Langerhans cells in the pathogenesis of skin infectious diseases is well studied; however, there are few articles addressing involvement of factor XIIIa-positive dermal dendrocytes (FXIIIa+ DD) in such processes. FXIIIa+ DDs are bone marrow-monocytic lineage-derived cells and members of the skin immune system. Due to their immune phenotype and functional characteristics, they are considered complementary cells to Langerhans cells in the process of antigen presentation and inducing immune response. To verify the interaction between FXIIIa+ DD and Leishmania amastigotes, 22 biopsies of American tegumentary leishmaniasis (ATL) skin lesions were subjected to double staining technique with anti-factor XIIIa and anti-Leishmania antibodies. FXIIIa+ DDs were hypertrophic and abundant in the cutaneous reaction of ATL. FXIIIa+ DDs harboring parasites were observed in I I of 22 skin biopsies. The data obtained suggest that FXIIIa+ DD plays a role in the pathogenesis of ATL skin lesion as host cell, immune effector, and/or antigen-presenting cell.

Ethnicity and Arterial Stiffness in Brazil

BACKGROUND The impact of increased central arterial stiffness as a predictor of morbidity and mortality, independently of other cardiovascular (CV) risk factors, has been established. The main aim of the present work was to investigate the association of ethnicity on arterial stiffness in different ethnic groups from the Brazilian population. METHODS A total of 1,427 individuals from the general population were randomly selected from the Vitoria City metropolitan area and 588 Amerindians from a native community in Brazil. The ethnicity of the general population was classified by a standard questionnaire as Caucasian descent, African descent, or Mulattos (considered racially mixed subjects). Pulse wave velocity (PWV) was measured with a noninvasive automatic device (Complior, Colson; Garges les Gonesses, France). RESULTS Hemodynamic data of PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) was higher in African descent individuals than in the other groups (P < 0.001). These results were still observed after adjustment for age and mean arterial pressure (P < 0.001). In addition, studying only normotensive individuals, PWV adjusted levels were higher in African descent individuals, and lower in Amerindians when compared with other ethnic groups (P < 0.01), showing, without the possible confounder effects of time and severity of hypertension or medication use, that PWV is associated with ethnicity in our population. CONCLUSION The study of different ethnic groups from a highly admixtured population was able to demonstrate an association between ethnicity and arterial stiffness.

Current Patient Management of Chronic Myeloid Leukemia in Latin America A Study by the Latin American Leukemia Net (LALNET)

BACKGROUND: Treatment recommendations have been developed for management of patients with chronic myeloid leukemia (CML). METHODS: A 30-item multiple-choice questionnaire was administered to 435 hematologists and oncohematologists in 16 Latin American countries. Physicians self-reported their diagnostic, therapeutic, and disease management strategies. RESULTS: Imatinib is available as initial therapy to 92% of physicians, and 42% of physicians have access to both second-generation tyrosine kinase inhibitors. Standard-dose imatinib is the preferred initial therapy for most patients, but 20% would manage a young patient initially with an allogeneic stem cell transplant from a sibling donor, and 10% would only offer hydroxyurea to an elderly patient. Seventy-two percent of responders perform routine cytogenetic analysis for monitoring patients on therapy, and 59% routinely use quantitative polymerase chain reaction. For patients who fail imatinib therapy, 61% would increase the dose of imatinib before considering change to a second-generation tyrosine kinase inhibitor, except for patients aged 60 years, for whom a switch to a second-generation tyrosine kinase inhibitor was the preferred choice. CONCLUSIONS: The answers to this survey provide insight into the management of patients with CML in Latin America. Some deviations from current recommendations were identified. Understanding the treatment patterns of patients with CML in broad population studies is important to identify needs and improve patient care. Cancer 2010;116:4991-5000. (C) 2070 American Cancer Society.

Salt-Induced Cardiac Hypertrophy and Interstitial Fibrosis Are Due to a Blood Pressure-Independent Mechanism in Wistar Rats

High salt intake is a known cardiovascular risk factor and is associated with cardiac alterations. To better understand this effect, male Wistar rats were fed a normal (NSD: 1.3% NaCl), high 4 (HSD4: 4%), or high 8 (HSD8: 8%) salt diet from weaning until 18 wk of age. The HSD8 group was subdivided into HSD8, HSD8+HZ (15 mg.kg(-1).d(-1) hydralazine in the drinking water), and HSD8+LOS (20 mg.kg(-1).d(-1) losartan in the drinking water) groups. The cardiomyocyte diameter was greater in the HSD4 and HSD8 groups than in the HSD8+LOS and NSD groups. Interstitial fibrosis was greater in the HSD4 and HSD8 groups than in the HSD8+HZ and NSD groups. Hydralazine prevented high blood pressure (BP) and fibrosis, but not cardiomyocyte hypertrophy. Losartan prevented high BP and cardiomyocyte hypertrophy, but not fibrosis. Angiotensin II type 1 receptor (AT(1)) protein expression in both ventricles was greater in the HSD8 group than in the NSD group. Losartan, but not hydralazine, prevented this effect. Compared with the NSD group, the binding of an AT(1) conformation-specific antibody that recognizes the activated form of the receptor was lower in both ventricles in all other groups. Losartan further lowered the binding of the anti-AT(1) antibody in both ventricles compared with all other experimental groups. Angiotensin II was greater in both ventricles in all groups compared with the NSD group. Myocardial structural alterations in response to HSD are independent of the effect on BP. Salt-induced cardiomyocyte hypertrophy and interstitial fibrosis possibly are due to different mechanisms. Evidence from the present study suggests that salt-induced AT(1) receptor internalization is probably due to angiotensin II binding. J. Nutr. 140: 1742-1751, 2010.

Predictive Factors for Positive Surgical Margins and Their Locations After Robot-Assisted Laparoscopic Radical Prostatectomy

Background: Positive surgical margin (PSM) after radical prostatectomy (RP) has been shown to be an independent predictive factor for cancer recurrence. Several investigations have correlated clinical and histopathologic findings with surgical margin status after open RP. However, few studies have addressed the predictive factors for PSM after robot-assisted laparoscopic RP (RARP). Objective: We sought to identify predictive factors for PSMs and their locations after RARP. Design, setting, and participants: We prospectively analyzed 876 consecutive patients who underwent RARP from January 2008 to May 2009. Intervention: All patients underwent RARP performed by a single surgeon with previous experience of > 1500 cases. Measurements: Stepwise logistic regression was used to identify potential predictive factors for PSM. Three logistic regression models were built: (1) one using preoperative variables only, (2) another using all variables (preoperative, intraoperative, and postoperative) combined, and (3) one created to identify potential predictive factors for PSM location. Preoperative variables entered into the models included age, body mass index (BMI), prostate-specific antigen, clinical stage, number of positive cores, percentage of positive cores, and American Urological Association symptom score. Intra-and postoperative variables analyzed were type of nerve sparing, presence of median lobe, percentage of tumor in the surgical specimen, gland size, histopathologic findings, pathologic stage, and pathologic Gleason grade. Results and limitations: In the multivariable analysis including preoperative variables, clinical stage was the only independent predictive factor for PSM, with a higher PSM rate for T3 versus T1c (odds ratio [OR]: 10.7; 95% confidence interval [CI], 2.6-43.8) and for T2 versus T1c (OR: 2.9; 95% CI, 1.9-4.6). Considering pre-, intra-, and postoperative variables combined, percentage of tumor, pathologic stage, and pathologic Gleason score were associated with increased risk of PSM in the univariable analysis (p < 0.001 for all variables). However, in the multivariable analysis, pathologic stage (pT2 vs pT1; OR: 2.9; 95% CI, 1.9-4.6) and percentage of tumor in the surgical specimen (OR: 8.7; 95% CI, 2.2-34.5; p = 0.0022) were the only independent predictive factors for PSM. Finally, BMI was shown to be an independent predictive factor(OR: 1.1; 95% CI, 1.0-1.3; p = 0.0119) for apical PSMs, with increasing BMI predicting higher incidence of apex location. Because most of our patients were referred from other centers, the biopsy technique and the number of cores were not standardized in our series. Conclusions: Clinical stage was the only preoperative variable independently associated with PSM after RARP. Pathologic stage and percentage of tumor in the surgical specimen were identified as independent predictive factors for PSMs when analyzing pre-, intra-, and postoperative variables combined. BMI was shown to be an independent predictive factor for apical PSMs. (C) 2010 European Association of Urology. Published by Elsevier B. V. All rights reserved.

Characteristics and Predictors of Obstructive Sleep Apnea in Patients With Systemic Hypertension

Obstructive sleep apnea (OSA) is a secondary cause of hypertension and independently associated with target-organ damage in hypertensive patients. However, OSA remains largely underdiagnosed and undertreated. The aim of the present study was to evaluate the characteristics and clinical predictors of OSA in a consecutive series of patients followed up in a hypertension unit. A total of 99 patients (age 46 +/- 11 years, body mass index 28.8 kg/m(2), range 25.1 to 32.9) underwent polysomnography. The clinical parameters included age, gender, obesity, daytime sleepiness, snoring, Berlin Questionnaire, resistant hypertension, and metabolic syndrome. Of the 99 patients, 55 (56%) had OSA (apnea-hypopnea index >5 events/hour). Patients with OSA were older and more obese, had greater levels of blood pressure, and presented with more diabetes, dyslipidemia, resistant hypenension, and metabolic syndrome than the patients without OSA. Of the patients with OSA, 51% had no excessive daytime sleepiness. The Berlin Questionnaire and patient age revealed a high sensitivity (0.93 and 0.91, respectively) but low specificity (0.59 and 0.48, respectively), and obesity and resistant hypertension revealed a low sensitivity (0.58 and 0.44, respectively) but high specificity (0.75 and 0.91, respectively) for OSA. Metabolic syndrome was associated with high sensitivity and specificity for OSA (0.86 and 0.85, respectively). Multiple regression analysis showed that age of 40 to 70 years (odds ratio 1.09, 95% confidence interval 1.03 to 1.16), a high risk of OSA on the Berlin Questionnaire (odds ratio 8.36, 95% confidence interval 1.67 to 41.85), and metabolic syndrome (odds ratio 19.04, 95% confidence interval 5.25 to 69.03) were independent variables associated with OSA. In conclusion, more important than the typical clinical features that characterize OSA, including snoring and excessive daytime sleepiness, the presence of the metabolic syndrome is as an important marker of OSA among patients with hypertension. (C) 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;105:1135-1139)