Mesenchymal Stem Cells Genetically Modified by Lentivirus-Express Soluble TRAIL and Interleukin-12 Inhibit Growth and Reduced Metastasis-Relate Changes in Lymphoma Mice Model.

BACKGROUND: Cancer treatment has many side effects; therefore, more efficient treatments are needed. Mesenchymal stem cells (MSC) have immunoregulatory properties, tumor site migration and can be genetically modified. Some proteins, such as soluble TRAIL (sTRAIL) and interleukin-12 (IL-12), have shown antitumoral potential, thus its combination in solid tumors could increase their activity. MATERIALS AND METHODS: Lentiviral transduction of bone marrow MSC with green fluorescent protein (GFP) and transgenes (sTRAIL and IL-12) was confirmed by fluorescence microscopy and Western blot. Soluble TRAIL levels were quantified by ELISA. Lymphoma L5178Y cells express a reporter gene (GFP/mCherry), and TRAIL receptor (DR5). RESULTS: An in vivo model showed that combined treatment with MSC expressing sTRAIL+IL-12 or IL-12 alone significantly reduced tumor volume and increased survival in BALB/c mice (p < 0.05) with only one application. However, at the histological level, only MSC expressing IL-12 reduced tumor cell infiltration significantly in the right gastrocnemius compared with the control group (p < 0.05). It presented less tissue dysplasia confirmed by fluorescence and hematoxylin-eosin dye; nevertheless, treatment not inhibited hepatic metastasis. CONCLUSIONS: MSC expressing IL-12, is or combination with BM-MSC expressing sTRAIL represents an antitumor strategy for lymphoma tumors since they increase survival and reduce tumor development. However, the combination did not show significative additive effect. The localized application did not inhibit metastasis but reduced morphological alterations of tissue associated with liver metastasis.

Repair of ovine peripheral nerve injuries with xenogeneic human acellular sciatic nerves prerecellularized with allogeneic Schwann-like cells-an innovative and promising approach.

INTRODUCTION: The iatrogenic effects of repairing peripheral nerve injuries (PNIs) with autografts (AGTs) encouraged the present study to involve a new approach consisting of grafting xenogeneic prerecellularized allogeneic cells instead of AGTs. METHODS: We compared sheep's AGT regenerative and functional capacity with decellularized human nerves prerecellularized with allogeneic Schwann-like cell xenografts (onwards called xenografts). Mesenchymal stem cells were isolated from ovine adipose tissue and induced in vitro to differentiate into Schwann-like cells (SLCs). Xenografts were grafted in ovine sciatic nerves. Left sciatic nerves (20 mm) were excised from 10 sheep. Then, five sheep were grafted with 20 mm xenografts, and five were reimplanted with their nerve segment rotated 180° (AGT). RESULTS: All sheep treated with xenografts or AGT progressively recovered the strength, movement, and coordination of their intervened limb, which was still partial when the study was finished at sixth month postsurgery. At this time, numerous intrafascicular axons were observed in the distal and proximal graft extremes of both xenografts or AGTs, and submaximal nerve electrical conduction was observed. The xenografts and AGT-affected muscles appeared partially stunted. CONCLUSIONS: Xenografts and AGT were equally efficacious in starting PNI repair and justified further studies using longer observation times. The hallmarks from this study are that human xenogeneic acellular scaffolds were recellularized with allogenic SCL and were not rejected by the nonhuman receptors but were also as functional as AGT within a relatively short time postsurgery. Thus, this innovative approach promises to be more practical and accessible than AGT or allogenic allografts and safer than AGT for PNI repair.

Chemosensitivity analysis and study of gene resistance on tumors and cancer stem cell isolates from patients with colorectal cancer.

Colorectal cancer (CRC) is one of the main causes of mortality. Recent studies suggest that cancer stem cells (CSCs) can survive after chemotherapy and promote tumor invasiveness and aggression. According to a higher hierarchy complexity of CSC, different protocols for isolation, expansion, and characterization have been used; however, there are no available resistance biomarkers that allow predicting the clinical response of treatment 5­fluorouracil (5FU) and oxaliplatin. Therefore, the primary aim of the present study was to analyze the expression of gene resistance on tumors and CSC­derived isolates from patients CRC. In the present study, adenocarcinomas of the colon and rectum (CRAC) were classified based on an in vitro adenosine triphosphate­based chemotherapy response assay, as sensitive and resistant and the percentage of CD24 and CD44 markers are evaluated by immunohistochemistry. To isolate resistant colon­CSC, adenocarcinoma tissues resistant to 5FU and oxaliplatin were evaluated. Finally, all samples were sequenced using a custom assay with chemoresistance­associated genes to find a candidate gene on resistance colon­CSC. Results showed that 59% of the CRC tissue analyzed was resistant and had a higher percentage of CD44 and CD24 markers. An association was found in the expression of some genes between the tumor­resistant tissue and CSC. Overall, isolates of the CSC population CD44+ resistant to 5FU and oxaliplatin demonstrated different expression profiles; however, the present study was able to identify overexpression of the KRT­18 gene, in most of the isolates. In conclusion, the results of the present study showed overexpression of KRT­18 in CD44+ cells is associated with chemoresistance to 5FU and oxaliplatin in CRAC.

Magnetite Nanoparticles Coated with PEG 3350-Tween 80: In Vitro Characterization Using Primary Cell Cultures.

Some medical applications of magnetic nanoparticles require direct contact with healthy tissues and blood. If nanoparticles are not designed properly, they can cause several problems, such as cytotoxicity or hemolysis. A strategy for improvement the biological proprieties of magnetic nanoparticles is their functionalization with biocompatible polymers and nonionic surfactants. In this study we compared bare magnetite nanoparticles against magnetite nanoparticles coated with a combination of polyethylene glycol 3350 (PEG 3350) and polysorbate 80 (Tween 80). Physical characteristics of nanoparticles were evaluated. A primary culture of sheep adipose mesenchymal stem cells was developed to measure nanoparticle cytotoxicity. A sample of erythrocytes from a healthy donor was used for the hemolysis assay. Results showed the successful obtention of magnetite nanoparticles coated with PEG 3350-Tween 80, with a spherical shape, average size of 119.2 nm and a zeta potential of +5.61 mV. Interaction with mesenchymal stem cells showed a non-cytotoxic propriety at doses lower than 1000 µg/mL. Interaction with erythrocytes showed a non-hemolytic propriety at doses lower than 100 µg/mL. In vitro information obtained from this work concludes that the use of magnetite nanoparticles coated with PEG 3350-Tween 80 is safe for a biological system at low doses.

The matrix synthesis and anti-inflammatory effect of autologous leukocyte-poor platelet rich plasma in human cartilage explants.

OBJECTIVE: To determine the effects of autologous leukocyte-poor platelet-rich plasma (LP-PRP) on the expression of markers involved in cartilage-extracellular matrix production and inflammation in cartilage explants bearing osteoarthritis. MATERIALS AND METHODS: Cartilage explants and LP-PRP were obtained from 10 patients who underwent total knee arthroplasty. The explants were cultured in spinner flasks for 28 days in the presence of interleukin (IL)-1ß and/or LP-PRP. The gene expression of catabolic (MMP13, ADAMTS5, and IL1ß) and anabolic factors (COL2A1, ACAN, and SOX9) was quantified. A histological assessment was performed according to a modified Mankin score, and quantification of type II and I collagen deposition. RESULTS: The gene expression of catabolic factors and the Mankin score were lower in LP-PRP- and LP-PRP/IL-1ß- than in IL-1ß-treated explants, suggesting less matrix degradation in explants cultured in the presence of LP-PRP. Higher expression of genes involved in cartilage matrix restoration was observed in LP-PRP and LP-PRP/IL-1ß- when compared to IL-1ß-treated explants. The explants treated with LP-PRP and LP-PRP/IL-1ß exhibited a higher deposition of type II collagen as well as a lower deposition of type I collagen and also better surface integrity and a significant increase in the number of chondrocytes. CONCLUSION: LP-PRP treatment favored restoration in early osteoarthritic cartilage and reduced the pro-inflammatory effect of IL-1ß. LP-PRP is a promising therapy for early osteoarthritis, as it promotes extracellular matrix repair, reduces inflammation, and slows cartilage degeneration.

Remarkably higher efficacy and a wider safety window for nonfrontline over first-line drug combinations in the adenocarcinoma Colo 320DM cell line.

PURPOSE: To determine in vitro, the efficacy and safety window of not-front-line and first-line anti-colorectal (CRC) drug combinations. METHODS: The adenocarcinoma cell line Colo 320DM and normal human mesenchymal stem cells derived from adipose tissue were used respectively to determine the anti-CRC efficacy (% of Colo 320DM cell death [CD]) and safety window [SW] - % Colo 320DM percent cancer death (PCD)/% of mesenchymal stem cell's death) of drug combinations, using the adenosine triphosphate-based chemotherapy response assay (ATP-CRA). RESULTS: First-line anti-CRC drug combinations (5-fluorouracil [5FU]/oxaliplatin [oxa] and 5-FU/Oxa /leucovorin [Leuco]) produced 57.7% and 52.4% CD, and 1.38 and 2.44 SW, respectively. Combinations of 5-FU/Oxa and 1 to 3 non-front line drugs led to 56.3-99.8% CD and to 0.96-2.2 SW. The highest safety window corresponded to 5FU/Oxa/ carboplatin [Carbo] (93% CD and 1.4 SW) and to 5-FU/ Oxa/cisplatin [Cispl] (93.5% CD and 1.4 SW). In contrast, non-front line drugs led to 89.8-97.4% CD and to 1.1-78.2 SW. Outstandingly, those combinations containing Carbo/ Cispl/3,3'-diindolylmethane (DIM), aspirin (Asp), or 3,3'- DIM/ Asp showed a very high CD (91.9-96.9% [39.2-39.5 times higher than first-line-combined drugs]) and very wide SW (57.8-81.56 [66.6-40 times higher than the first-line drug combinations]). CONCLUSIONS: Human mesenchymal stem cells could be an excellent alternative to laboratory animals, when testing the safety profiles of drugs. The most promising combinations of non-frontline drugs to treat CRC are Carbo/Cispl/ Asp and Carbo/Cispl/DIM.

Implant Composed of Demineralized Bone and Mesenchymal Stem Cells Genetically Modified with AdBMP2/AdBMP7 for the Regeneration of Bone Fractures in Ovis aries.

Adipose-derived mesenchymal stem cells (ADMSCs) are inducible to an osteogenic phenotype by the bone morphogenetic proteins (BMPs). This facilitates the generation of implants for bone tissue regeneration. This study evaluated the in vitro osteogenic differentiation of ADMSCs transduced individually and in combination with adenoviral vectors expressing BMP2 and BMP7. Moreover, the effectiveness of the implant containing ADMSCs transduced with the adenoviral vectors AdBMP2/AdBMP7 and embedded in demineralized bone matrix (DBM) was tested in a model of tibial fracture in sheep. This graft was compared to ewes implanted with untransduced ADMSCs embedded in the same matrix and with injured but untreated animals. In vivo results showed accelerated osteogenesis in the group treated with the AdBMP2/AdBMP7 transduced ADMSC graft, which also showed improved restoration of the normal bone morphology.

Human papillomavirus type 2 associated with pyogenic granuloma in patients without clinical evidence of warts.

BACKGROUND: Pyogenic granuloma is a non-neoplastic lesion that frequently occurs in the skin and mucous membranes of children and pregnant women. The anatomical sites of pyogenic granulomas overlap with those of wart infections caused by the human papillomavirus (HPV). OBJECTIVE: This study assessed the presence of HPV DNA in pyogenic granuloma samples by polymerase chain reaction. METHODS: Eighteen pyogenic granuloma biopsies from patients without a clinical history or evidence of verruca in the studied area were tested for the presence of the HPV genome. The presence of HPV DNA was screened by three independent polymerase chain reaction reactions using standard consensus primer sets targeted to the L1 or E1 consensus regions of HPV genome. The HPV DNA-positive samples were genotyped using methodologies enabling the identification of up to 30 HPVs, including oncogenic, nononcogenic, and cutaneous viral types. RESULTS: The HPV DNA was detected in 44.4% (eight of 18) of the samples, with HPV-2 being the only type in the eight HPV DNA-positive samples. Contamination with HPV-2 sequences throughout the entire process was reliably eliminated. CONCLUSION: This report is the first to suggest an association between HPV-2 and pyogenic granuloma. This relationship is similar to that observed between HPV-2 and nongenital warts.

A de novo t(10;19)(q22.3;q13.33) leads to ZMIZ1/PRR12 reciprocal fusion transcripts in a girl with intellectual disability and neuropsychiatric alterations.

We report a girl with intellectual disability (ID), neuropsychiatric alterations, and a de novo balanced t(10;19)(q22.3;q13.33) translocation. After chromosome sorting, fine mapping of breakpoints by array painting disclosed disruptions of the zinc finger, MIZ-type containing 1 (ZMIZ1) (on chr10) and proline-rich 12 (PRR12) (on chr19) genes. cDNA analyses revealed that the translocation resulted in gene fusions. The resulting hybrid transcripts predict mRNA decay or, if translated, formation of truncated proteins, both due to frameshifts that introduced premature stop codons. Though other molecular mechanisms may be operating, these results suggest that haploinsufficiency of one or both genes accounts for the patient's phenotype. ZMIZ1 is highly expressed in the brain, and its protein product appears to interact with neuron-specific chromatin remodeling complex (nBAF) and activator protein 1 (AP-1) complexes which play a role regulating the activity of genes essential for normal synapse and dendrite growth/behavior. Strikingly, the patient's phenotype overlaps with phenotypes caused by mutations in SMARCA4 (BRG1), an nBAF subunit presumably interacting with ZMIZ1 in brain cells as suggested by our results of coimmunoprecipitation in the mouse brain. PRR12 is also expressed in the brain, and its protein product possesses domains and residues thought to be related in formation of large protein complexes and chromatin remodeling. Our observation from E15 mouse brain cells that a Prr12 isoform was confined to nucleus suggests a role as a transcription nuclear cofactor likely involved in neuronal development. Moreover, a pilot transcriptome analysis from t(10;19) lymphoblastoid cell line suggests dysregulation of genes linked to neurodevelopment processes/neuronal communication (e.g., NRCAM) most likely induced by altered PRR12. This case represents the first constitutional balanced translocation disrupting and fusing both genes and provides clues for the potential function and effects of these in the central nervous system.

Understanding the colon cancer stem cells and perspectives on treatment.

An area of research that has been recently gaining attention is the relationship between cancer stem cell (CSC) biology and chemo-resistance in colon cancer patients. It is well recognized that tumor initiation, growth, invasion and metastasis are promoted by CSCs. An important reason for the widespread interest in the CSC model is that it can comprehensibly explain essential and poorly understood clinical events, such as therapy resistance, minimal residual disease, and tumor recurrence. This review discusses the recent advances in colon cancer stem cell research, the genes responsible for CSC chemoresistance, and new therapies against CSCs.

The tumor necrosis factor α (-308 A/G) polymorphism is associated with cystic fibrosis in Mexican patients.

UNLABELLED: Environmental and genetic factors may modify or contribute to the phenotypic differences observed in multigenic and monogenic diseases, such as cystic fibrosis (CF). An analysis of modifier genes can be helpful for estimating patient prognosis and directing preventive care. The aim of this study is to determine the association between seven genetic variants of four modifier genes and CF by comparing their corresponding allelic and genotypic frequencies in CF patients (n = 81) and control subjects (n = 104). Genetic variants of MBL2 exon 1 (A, B, C and D), the IL-8 promoter (-251 A/T), the TNFα promoter (TNF1/TNF2), and SERPINA1 (PI*Z and PI*S) were tested in CF patients and control subjects from northeastern Mexico by PCR-RFLP. RESULTS: The TNF2 allele (P = 0.012, OR 3.43, 95% CI 1.25-9.38) was significantly associated with CF under the dominant and additive models but was not associated with CF under the recessive model. This association remained statistically significant after adjusting for multiple tests using the Bonferroni correction (P = 0.0482). The other tested variants and genotypes did not show any association with the disease. CONCLUSION: An analysis of seven genetic variants of four modifier genes showed that one variant, the TNF2 allele, appears to be significantly associated with CF in Mexican patients.

Analyses of chondrogenic induction of adipose mesenchymal stem cells by combined co-stimulation mediated by adenoviral gene transfer.

INTRODUCTION: Adipose-derived stem cells (ASCs) have the potential to differentiate into cartilage under stimulation with some reported growth and transcriptional factors, which may constitute an alternative for cartilage replacement approaches. In this study, we analyzed the in vitro chondrogenesis of ASCs transduced with adenoviral vectors encoding insulin-like growth factor-1 (IGF-1), transforming growth factor beta-1 (TGF-ß1), fibroblast growth factor-2 (FGF-2), and sex-determining region Y-box 9 (SOX9) either alone or in combinations. METHODS: Aggregate cultures of characterized ovine ASCs were transduced with 100 multiplicity of infections of Ad.IGF-1, Ad.TGF-ß1, Ad.FGF-2, and Ad.SOX9 alone or in combination. These were harvested at various time points for detection of cartilage-specific genes expression by quantitative real-time PCR or after 14 and 28 days for histologic and biochemical analyses detecting proteoglycans, collagens (II, I and X), and total sulfated glycosaminoglycan and collagen content, respectively. RESULTS: Expression analyses showed that co-expression of IGF-1 and FGF-2 resulted in higher significant expression levels of aggrecan, biglycan, cartilage matrix, proteoglycan, and collagen II (all P ≤0.001 at 28 days). Aggregates co-transduced with Ad.IGF-1/Ad.FGF-2 showed a selective expression of proteoglycans and collagen II, with limited expression of collagens I and × demonstrated by histological analyses, and had significantly greater glycosaminoglycan and collagen production than the positive control (P ≤0.001). Western blot analyses for this combination also demonstrated increased expression of collagen II, while expression of collagens I and × was undetectable and limited, respectively. CONCLUSION: Combined overexpression of IGF-1/FGF-2 within ASCs enhances their chondrogenic differentiation inducing the expression of chondrogenic markers, suggesting that this combination is more beneficial than the other factors tested for the development of cell-based therapies for cartilage repair.

Human bone morphogenetic protein 2-transduced mesenchymal stem cells improve bone regeneration in a model of mandible distraction surgery.

BACKGROUND: Bone morphogenetic proteins (BMPs) are actively involved in ossification, and BMP-2 participates throughout the entire process. Gene therapy for bone regeneration using adenovirus-expressing BMPs has been successful in small mammals, but it has not been satisfactory in large mammals. METHODS: We generated a 3-component implant (3C graft) comprising autologous mesenchymal stem cells (MSCs), ex vivo transduced with an adenovirus vector-expressing BMP-2 and embedded in a demineralized human bone matrix (DBM). RESULTS: In vitro studies demonstrated vector-induced osteogenesis; osteoblast population and mineralization of the extracellular matrix were greater in the vector-transduced cultures than in the controls (nontransduced MSCs stimulated with osteogenic media were used as positive controls, and nontransduced MSCs served as a negative control). The 3-component grafts were used to fill osteotomies created by bone distraction surgery in mongrel dogs. Control groups comprised dogs with bone distraction alone and dogs with nontransduced MSC grafts. The radiography follow-up, performed 10 weeks after distraction, demonstrated a remarkable reduction in the consolidation period compared with controls. Postmortem mandibles submitted for anatomic and histologic analyses showed improved remodeling and bone maturation in the 3C-grafted dogs. Inflammatory infiltrates were not observed in any of the treated areas, and no liver toxicity was detected. CONCLUSIONS: We demonstrated acceleration of osteogenesis in a dog model for bone distraction by using an implant of BMP-2 modified MSCs. These results are helpful for future clinical trials of mandible bone distraction.

Treatment of vitiligo with a melanocyte-keratinocyte cell suspension versus dermabrasion only: a pilot study with a 12-month follow up.

BACKGROUND: Dermabrasion is a surgical procedure that has been used for repigmentation; however, autologous transplantation of uncultured melanocytes in a suspension combined with the use of adjunct treatment provides better results. PURPOSE: To evaluate the clinical effectiveness of dermoabrasion (DA) and melanocyte-keratinocyte cell suspension transplantation (DA+MKT) vs. dermabrasion with no adjunct treatment. MATERIALS AND METHODS: We selected 11 patients (six women and five men) with stable vitiligo. From these, two achromic maculae of similar size were selected. One macule was treated with DA+MKT and the other with DA only. The main parameter of treatment efficacy was the percentage of repigmentation in the area treated, three and 12 months after implantation. RESULTS: In seven of the 11 patients, slightly better pigmentation occurred with DA+MKT. Two of these patients had a repigmentation greater than 50 percent and in two other patients, the result was similar for both techniques, although slightly better with MKT. Two more patients showed less than 20 percent repigmentation, but only in the area treated with DA+MKT. One patient showed pigmentation initially after DA+MKT only, and subsequent depigmentation. CONCLUSION: DA+MKT produced slightly better repigmentation than DA only when given without adjunct treatment in a 12-month follow-up period.

Ancestry informative markers and admixture proportions in northeastern Mexico.

To investigate the ancestral admixture in the Mestizo population in northeastern Mexico, we genotyped 74 ancestral informative markers (AIMs) and 15 Y-single-nucleotide polymorphisms (Y-SNPs) in 100 individuals. The Native American contribution is 56% (range: 27.4-81.2%), the European contribution is 38% (range: 16.7-70.5%) and the West African contribution is 6%. The results show a higher European contribution than was reported in other similar studies in the country, albeit with a predominant Native American ancestry. No remarkable differences in the ancestry proportions were observed using subgroups of 74, 54, 34 and 24 AIMs. The paternal lineage calculated by genotyping of 15 Y-SNPs, shows a major component of European and Eurasian ancestry markers ( approximately 78%), compared with Amerindian ( approximately 12%) and African markers (10%). This information will set a reference for future determinations of admixture proportions in the Mestizo population from Mexico and for population-based association studies of complex diseases.

Effect of clofibric acid on desmin and vimentin contents in rat myocardiocytes.

The aim of this experimental study was to analyze in vitro effects of clofibric acid on vimentin and desmin contents in rat myocardiocytes, which was carried out in primary myocardiocyte cells that were treated only with clofibric acid at 0.1 mM. The measurement of vimentin and desmin were done by Western blotting and densitometry. This study showed that myocardiocytes exposed to clofibric acid exhibit a 26.3% decrease in vimentin and a 42.1% decrease in desmin. Considering the role that these intermediate filaments play in the anchorage and cellular organization of myocardiocytes, the decrease of desmin and vimentin observed in cells treated with clofibric acid may be partially responsible for the adverse effects observed in patients. In conclusion, the alteration of cytoskeletal proteins may be a cause of cardiopathy in patients treated with these compounds.

Trichomonas vaginalis: identification of soluble and membrane-associated phospholipase A1 and A2 activities with direct and indirect hemolytic effects.

A direct hemolytic activity, dependent on phospholipase A (PLA) activity, was located in the particulate subcellular fraction (P30) of Trichomonas vaginalis. We identified soluble direct and indirect hemolytic activities in the spent medium and soluble fraction (S30) of T. vaginalis strain GT-13. Spent medium showed the highest specific indirect hemolytic activity (SIHA) at pH 6.0 (91 indirect hemolytic units [HU]/mg/hr). Spent medium and P30, but not S30, showed direct hemolytic activity. PLA activity was protein dose dependent and time dependent. The highest PLA activity was observed at pH 6.0. All trichomonad preparations showed phospholipase A1 (PLA A1) and phospholipase A2 (PLA A2) activities. Indirect and direct hemolytic activity and PLA A1 and PLA A2 diminished at pH 6.0 and 8.0 with increasing concentrations of Rosenthal's inhibitor. The greatest effect was observed with 80 microM at pH 6.0 on the SIHA of S30 (83% reduction) and the lowest at pH 8.0, also on the SIHA of S30 (26% reduction). In conclusion, T. vaginalis contains particulate and soluble acidic, and alkaline direct and indirect hemolytic activities, which are partially dependent on alkaline or acidic PLA A1 and PLA A2 enzymes. These could be responsible for the contact-dependent and -independent hemolytic and cytolytic activities of T. vaginalis.

Hormone and metabolic factors associated with leptin mRNA expression in pre- and postmenopausal women.

Recent information has extended leptin's action, beyond the control of appetite, to various sites of metabolic regulation. To better understand leptin's role we studied its production in subcutaneous and visceral fat compartments before and after menopause. During elective abdominal surgery, biopsies of subcutaneous and omental tissues were taken from 20 women at pre- (BMI 28.4 +/- 4.5 kg/m2) and 10 at postmenopause (BMI 30.6 +/- 7.7 kg/m2). In both groups serum leptin levels were similar, and highly correlated with BMI. In subcutaneous adipose tissue, leptin mRNA expression was significantly higher in pre- than in postmenopausal women (50.4 +/- 20.5 amol/microg total RNA versus 34.5 +/- 24.9 amol/microg total RNA, respectively). Leptin mRNA expression in subcutaneous tissue was independently correlated with fasting glucose (R = 0.89, P < 0.006) at premenopause, and with serum estradiol (R = 0.77, P < 0.04) at postmenopause. Leptin mRNA expression in visceral fat was correlated with DHEAS (R = 0.86, P < 0.001), at premenopause. These results indicate that in both compartments, leptin production is sensitive to different but overlapping stimuli, conveying information about energy availability to central and peripheral sites under different conditions of estrogen exposure.

[A tetracycline-inducible gene system allows for regulated production of proteins with therapeutic potential]. / El sistema génico inducible por tetraciclina permite la producción regulada de proteínas con potencial terapéutico.

The adoption of a bacterial system of control of genic expression with tetracycline, combined with the advances in the identification of regulatory sequences and mechanisms of expression of eukaryotic genes, has increased the versatility and effectiveness of techniques to reintroduce and to make genes function in cells and in superior organisms by being able to control the activity of the transgene in a temporary or reversible manner. This approach has also facilitated making detailed studies of different cellular processes and diseases; for example, the study of the function of oncogenes and other genes involved in the formation and progression of cancer, the generation of cellular models for recombinant protein production with therapeutic purposes, the ex-vivo genetic manipulation of extracted cells from patients and returned to them for gene therapy procedures, as well as the modulation of transgenes to revert hereditary suffering in animal models.

Trichomonas vaginalis: identification of a phospholipase A-dependent hemolytic activity in a vesicular subcellular fraction.

Trichomonad total extracts (TTE), or vesicular (P30) and soluble (530) subcellular fractions from 3 pathogenic Trichomonas vaginalis strains (GT-3. GT-13. and GT-15), lysed both human and Sprague-Dawley rat erythrocytes in a time- and dose-dependent manner. The entire hemolytic activity of TTE was located in P30, showing 2 peaks of maximum activity, one at pH 6.0 and another at pH 8.0. in the presence of 1 mM Ca2+. Hemolytic activity on rat erythrocytes was greater at pH 6.0 16.71 +/- 0.33 hemolytic units IHU]/mg/hr to 11.60 +/- 0.24 HU/mg/hr) than at pH 8.0 (3.81 +/- 0.30 HU/mg/hr to 5.75 +/- 0.65 HU/mg/hr). and it was greater than that on human red blood cells at pH 6.0 (2.67 +/- 0.19 HU/mg/hr to 4.08 +/- 0.15 HU/mg/hr) or pH 8.0 (2.24 +/- 0.0 9 HU/mg/hr to 2.81 +/- 0.06 HU/mg/hr). The alkaline and acidic hemolytic activity diminished (60-93% at pH 6.0 and 78-93% at pH 8.0) by the effect of 80 microM Rosenthal's inhibitor, which also inhibited 27-45% and 29-54% trichomonad alkaline and acidic phospholipase A activities, respectively. Vesicles, vacuoles, and hydrogenosomes were rich in P30. Trichomonas vaginalis has a hemolytic PLA, which could be involved in its cytopathogenic mechanism.