Carmen M. Gurrola-Díaz

Effects of Hibiscus sabdariffa extract powder and preventive treatment (diet) on the lipid profiles of patients with metabolic syndrome (MeSy).

Insulin resistance, obesity, hypertension, and dyslipidemia are strongly associated with metabolic syndrome (MeSy), which is considered to be a reversible clinical stage before its evolution to coronary heart disease and diabetes. Currently, the antihypertensive and hypolipidemic properties of aqueous Hibiscus sabdariffa extracts (HSE) have been demonstrated in clinical trials and in vivo experiments. The aim of the present study was to evaluate the effects of a Hibiscus sabdariffa extract powder (HSEP) and a recognized preventive treatment (diet) on the lipid profiles of individuals with and without MeSy according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. The protocol was a follow-up study carried out in a factorial, randomized design (T1=preventive treatment comprises Diet, T2=HSEP, T3=HSEP+preventive treatment (Diet) X MeSy, non-MeSy individuals). A total daily dose of 100 mg HSEP was orally administered in capsules for one month. The preventive treatment (diet) was selected according to NCEP-ATP III recommendations and adjusted individually. Total cholesterol, LDL-c, HDL-c, VLDL-c, triglycerides, glucose, urea, creatinine, AST, and ALT levels in the blood were determined in all individuals pre- and post-treatment. The MeSy patients treated with HSEP had significantly reduced glucose and total cholesterol levels, increased HDL-c levels, and an improved TAG/HDL-c ratio, a marker of insulin resistance (t-test p<0.05). Additionally, a triglyceride-lowering effect was observed in MeSy patients treated with HSEP plus diet, and in individuals without MeSy treated with HSEP. Significant differences in total cholesterol, HDL-c, and the TAG/HDL-c ratio were found when the means of absolute differences among treatments were compared (ANOVA p<0.02). Therefore, in addition to the well documented hypotensive effects of Hibiscus sabdariffa, we suggest the use of HSEP in individuals with dyslipidemia associated with MeSy.

P16INK4a immunohistochemistry improves the reproducibility of the histological diagnosis of cervical intraepithelial neoplasia in cone biopsies

OBJECTIVE Cervical cancer is currently the most frequently occurring cancer among women in Mexico. Mexican cervical cancer prevention programs have been unsatisfactory in part because the tests used to diagnose precursor lesions have poor reproducibility. The implementation of specific biomarkers may overcome these limitations. Here, we analyzed whether immunohistochemistry for p16(INK4a) could improve the reproducibility of histopathological diagnoses of cervical precancerous lesions. METHODS Serial sections of 78 specimens were stained for H&E and p16(INK4a) and independently interpreted by three Mexican pathologists. Specimens were interpreted and categorized in two ways: 1) four diagnostic categories including negative lesions, CIN1, CIN2, and CIN3, or 2) two diagnostic categories; either lesions that do not require therapy (negative, CIN1), or lesions that require therapy (>or=CIN2). The agreement in diagnoses between pairs of observers was evaluated by kappa statistics. RESULTS The best concordance in diagnosing was observed with two categories and p16(INK4a) staining. Interestingly, the overall diagnostic discordances of higher than one CIN grade were 26.1% for H&E and 9.20% for p16(INK4a) (P<0.001). Using four diagnostic categories, weighted kappa values for each pair of observers were 0.28, 0.15, and 0.36 for H&E and 0.34, 0.35, and 0.60 for p16(INK4a) stains. Using two diagnostic categories, kappa values were 0.36, 0.12, and 0.18 for H&E and 0.59, 0.70, and 0.59, p16(INK4a) stains. CONCLUSION These data show that p16(INK4a) immunohistochemistry substantially improved the reproducibility of interpreting histological slides. This approach may result in more accurate diagnoses and improved clinical management of patients with cervical precancerous lesions in Mexico and elsewhere.

Genetic Polymorphisms of Genes Coding to Alcohol-Metabolizing Enzymes in Western Mexicans: Association of CYP2E1*c2/CYP2E1*5B Allele with Cirrhosis and Liver Function

BACKGROUND Alcoholic cirrhosis constitutes a major public health problem in the world where ADH1B, ALDH2, and CYP2E1 polymorphisms could be playing an important role. We determined ADH1B*2, ALDH2*2, and CYP2E1*c2 allele frequencies in healthy control individuals (C) and patients with alcoholic cirrhosis (AC) from western Mexico. METHODS Ninety C and 41 patients with AC were studied. Genotype and allele frequency were determined through polymerase chain reaction-restriction fragment length polymorphisms. RESULTS Polymorphic allele distribution in AC was 1.6%ADH1B*2, 0.0%ALDH2*2, and 19.5%CYP2E1*c2; in C: 6.1%ADH1B*2, 0%ALDH2*2, and 10.6%CYP2E1*c2. CYP2E1*c2 polymorphic allele and c1/c2 genotype frequency were significantly higher (p < 0.05 and p < 0.01, respectively) in patients with AC when compared to C. Patients with AC, carrying the CYP2E1*c2 allele, exhibited more decompensated liver functioning evaluated by total bilirubin and prothrombin time, than c1 allele carrying patients (p < 0.05). Cirrhosis severity, assessed by Childs Pugh score and mortality, was higher in patients carrying the c2 allele, although not statistically significant. CONCLUSIONS In this study, CYP2E1*c2 allele was associated with susceptibility to AC; meanwhile, ADH1B*2 and ALDH2*2 alleles were not. CYP2E1*c2 allele was associated with AC severity, which could probably be attributed to the oxidative stress promoted by this polymorphic form. Further studies to clearly establish CYP2E1*c2 clinical relevance in the development of alcohol-induced liver damage and its usefulness as a probable prognostic marker, should be performed. Also, increasing the number of patients and including a control group conformed by alcoholic patients free of liver damage may render more conclusive results. These findings contribute to the understanding of the influence of gene variations in AC development among populations, alcohol metabolism, and pharmacogenetics.

TGF-β1 serum concentration as a complementary diagnostic biomarker of lung cancer: establishment of a cut-point value

Lung cancer is a malignant disease with increasing mortality rates. Cytokines play a role in normal cell growth regulation and differentiation and are also implicated in malignant disease. Among these cytokines, Transforming Growth Factor β type 1 (TGF‐β1) acts as a tumor promoter in malignant cells. Several clinical studies have found high levels of TGF‐β1 in various cancer types. The aim of this study was to establish a TGF‐β1 cut‐off point as a complementary diagnostic tool in lung cancer detection. Therefore, 72 clinically well‐characterized individuals were studied, 41 lung cancer patients and 31 healthy subjects. Serum TGF‐β1 concentration was measured by an enzyme‐linked immunosorbent assay (ELISA). We compared statistically the serum TGF‐β1 concentration between both groups with analysis of variance, linear regression and receiver operating curve analysis. We observed that lung cancer patients produced higher TGF‐β1 levels than healthy individuals (37,225±9,436 vs. 28,416±9,324 pg/ml, P<0.001). The cut‐point diagnostic value was 30,500 pg/ml with 80.5% sensitivity, 64.5% specificity and odds ratio: 7.5, 95% CI: 2.6–21.8. Conclusions: We found significantly higher TGF‐β1 levels in lung cancer patients than in healthy individuals. We propose the measurement of serum TGF‐β1 levels as a complementary diagnostic test in lung cancer detection. J. Clin. Lab. Anal. 25:238–243, 2011.

Establishment of a cut‐point value of serum TNF‐α levels in the metabolic syndrome

Cardiovascular diseases and type 2 diabetes are the major causes of mortality in Mexico. Metabolic syndrome (MS) is a cluster of factors that increase the risk to develop such diseases. Previous studies have shown that MS is associated with high tumor necrosis factor (TNF‐α) levels. In fact, TNF‐α has been proposed to be a useful marker for clinical diagnosis of inflammation at an early stage. Therefore, we analyzed TNF‐α concentrations in Mexican individuals with or without MS and related these levels to the associated MS components. Clinical, anthropometric, and biochemical data were analyzed in 41 healthy and 39 MS individuals. Individuals were similarly grouped by age and gender.The serum TNF‐α levels measured bya highly sensitive enzyme‐linked immunosorbent assay (ELISA) kit were increased significantly in MS subjects compared with healthy individuals (P<0.001). The assay showed 78.1% sensitivity and 61.5% specificity with a cut‐point level of 1.36 pg/mL. TNF‐α levels higher than the cut‐point value were correlated with insulin resistance indices. These findings support the hypothesis that serum TNF‐α concentration could be a useful marker for early MS diagnosis. Nevertheless, we suggest the establishment of specific cut‐point values in each studied population to evaluate potential clinical applications. J. Clin. Lab. Anal. 23:51–56, 2009.

A cut-point value of uncarboxylated to carboxylated index is associated with glycemic status markers in type 2 diabetes.

Background The uncarboxylated osteocalcin (ucOC) has been described as a regulator of glucose metabolism in mice, and it is decreased in human type 2 diabetes mellitus (T2D). Although inversely correlated with serum glucose, insulin, and glycated hemoglobin, it is unclear if ucOC decrement is caused by diabetes or plays a role in the pathogenesis and/or progression of the disease. Whatever the case may be, diabetes affects osteoblast gene expression, and possibly the proportion of ucOC over carboxylated OC (cOC). The association of ucOC/cOC index with glycemic status markers in patients with T2D has not been described before. Objective The objective of this study was to assess the ucOC/cOC index and its relationship with glycemic status markers in patients with T2D. Methods The ucOC/cOC index was determined by the quotient of ucOC and cOC serum levels in 80 T2D patients and 160 healthy subjects. The relationship between the ucOC/cOC index and glycemic status markers was evaluated. Results The ucOC/cOC index was low and negatively correlated to fasting plasma glucose and homeostasis assessment-insulin resistance model in T2D patients. The odds ratio for T2D patients with an ucOC/cOC index below the cut-point obtained by receiver operating characteristic analysis was 12.64 (confidence interval, 5.75–27.77; P < 0.001). Conclusions A value of ucOC/cOC index less than 0.3 is associated with markers of poor metabolic control in patients with T2D.

MEIS1, PREP1, and PBX4 Are Differentially Expressed in Acute Lymphoblastic Leukemia: Association of MEIS1 Expression with Higher Proliferation and Chemotherapy Resistance

BackgroundThe Three-amino acid-loop-extension (TALE) superfamily of homeodomain-containing transcription factors have been implicated in normal hematopoiesis and in leukemogenesis and are important survival, differentiation, and apoptosis pathway modulators. In this work, we determined the expression levels of TALE genes in leukemic-derived cell lines, in blood samples of patients with Acute lymphoblastic leukemia (ALL), and in the blood samples of healthy donors.ResultsHere we show increased expression of MEIS1, MEIS2, and PREP1 genes in leukemia-derived cell lines compared with blood normal cells. High levels of MEIS1 and PREP1, and low levels of PBX4 expression were also founded in samples of patients with ALL. Importantly, silencing of MEIS1 decreases the proliferation of leukemia-derived cells but increases their survival after etoposide treatment. Etoposide-induced apoptosis induces down-regulation of MEIS1 expression or PREP1 up-regulation in chemotherapy-resistant cells.ConclusionsOur results indicate that up-regulation of MEIS1 is important for sustaining proliferation of leukemic cells and that down-regulation of MEIS1 or up-regulation of PREP1 and PBX genes could be implicated in the modulation of the cellular response to chemotherapeutic-induced apoptosis.

Lupanine Improves Glucose Homeostasis by Influencing KATP Channels and Insulin Gene Expression

The glucose-lowering effects of lupin seeds involve the combined action of several components. The present study investigates the influence of one of the main quinolizidine alkaloids, lupanine, on pancreatic beta cells and in an animal model of type-2 diabetes mellitus. In vitro studies were performed with insulin-secreting INS-1E cells or islets of C57BL/6 mice. In the in vivo experiments, hyperglycemia was induced in rats by injecting streptozotocin (65 mg/kg body weight). In the presence of 15 mmol/L glucose, insulin secretion was significantly elevated by 0.5 mmol/L lupanine, whereas the alkaloid did not stimulate insulin release with lower glucose concentrations. In islets treated with l-arginine, the potentiating effect of lupanine already occurred at 8 mmol/L glucose. Lupanine increased the expression of the Ins-1 gene. The potentiating effect on secretion was correlated to membrane depolarization and an increase in the frequency of Ca2+ action potentials. Determination of the current through ATP-dependent K+ channels (KATP channels) revealed that lupanine directly inhibited the channel. The effect was dose-dependent but, even with a high lupanine concentration of 1 mmol/L or after a prolonged exposure time (12 h), the KATP channel block was incomplete. Oral administration of lupanine did not induce hypoglycemia. By contrast, lupanine improved glycemic control in response to an oral glucose tolerance test in streptozotocin-diabetic rats. In summary, lupanine acts as a positive modulator of insulin release obviously without a risk for hypoglycemic episodes.