Pore geometry influences growth and cell adhesion of infrapatellar mesenchymal stem cells in biofabricated 3D thermoplastic scaffolds useful for cartilage tissue engineering

The most pressing need in cartilage tissue engineering (CTE) is the creation of a biomaterial capable to tailor the complex extracellular matrix of the tissue. Despite the standardized used of polycaprolactone (PCL) for osteochondral scaffolds, the pronounced stiffness mismatch between PCL scaffold and the tissue it replaces remarks the biomechanical incompatibility as main limitation. To overcome it, the present work was focused in the design and analysis of several geometries and pore sizes and how they affect cell adhesion and proliferation of infrapatellar fat pad-derived mesenchymal stem cells (IPFP-MSCs) loaded in biofabricated 3D thermoplastic scaffolds. A novel biomaterial for CTE, the 1,4-butanediol thermoplastic polyurethane (b-TPUe) together PCL were studied to compare their mechanical properties. Three different geometrical patterns were included: hexagonal (H), square (S), and, triangular (T); each one was printed with three different pore sizes (PS): 1, 1.5 and 2 mm. Results showed differences in cell adhesion, cell proliferation and mechanical properties depending on the geometry, porosity and type of biomaterial used. Finally, the microstructure of the two optimal geometries (T1.5 and T2) was deeply analyzed using multiaxial mechanical tests, with and without perimeters, μCT for microstructure analysis, DNA quantification and degradation assays. In conclusion, our results evidenced that IPFP-MSCs-loaded b-TPUe scaffolds had higher similarity with cartilage mechanics and T1.5 was the best adapted morphology for CTE.

Molecular identification of Leishmania tropica and L. infantum isolated from cutaneous human leishmaniasis samples in central Morocco

BACKGROUND & OBJECTIVES

Cutaneous leishmaniasis (CL) in Marrakesh-Safi region located in the central-south part of Morocco is a public health problem. This study assessed the efficiency of a microscopic examination method in establishing the diagnosis of CL and PCR for the characterization and identification of the circulating Leishmania strains in different CL foci of the study area.

METHODS

A total of 297 smears obtained from cutaneous lesions of suspected patients with CL were stained with May-Grünwald Giemsa (MGG) for microscopic examination. For each positive smear, genomic DNA was extracted and PCR-analysed, targeting the small subunit ribosomal ribonucleic acid (ssu rRNA) gene to detect Leishmania DNA. Then, the internal transcribed spacer 1 (ITS1) was amplified and sequenced in order to identify the Leishmania species. The sensitivity and specificity of the conventional microscopy with ssu rRNA gene were compared by Leishmania nested PCR (LnPCR) and ITS1 gene by ITS-PCR.

RESULTS

A total of 257 smears were positive in the microscopic examination, i.e. the detection rate of amastigotes by optical microscopy was 86.53% (257/297). The LnPCR was found to have a specificity and a sensitivity of 100%, each. Interestingly, the sequencing results showed that 99.61% (256/257) of the isolates had Leishmania tropica and 0.39% (1/257) had L. infantum infection.

INTERPRETATION & CONCLUSION

Though, classical microscopic examination is useful and economical, it is not sensitive enough, especially in endemic regions where several Leishmania species coexist. In such situations, PCR constitutes a complementary method for the identification of the causal species. The results indicate that both the L. tropica (dominant) and L. infantum are the causative agents of CL in the Marrakesh-Safi region. The rate of CL infection is high in Imintanout, and Chichaoua provinces. Hence, early diagnosis and prompt treatment of CL patients is necessary to prevent its extension to neighboring localities.

Randomized clinical trial of intracorporeal versus extracorporeal anastomosis in laparoscopic right colectomy (IEA trial)

BACKGROUND

Several non-randomized and retrospective studies have suggested that intracorporeal anastomosis (IA) has advantages over extracorporeal anastomosis (EA) in laparoscopic right colectomy, but scientific evidence is lacking. The aim was to compare short-term outcomes and to define the possible benefits of IA compared with EA in elective laparoscopic right colectomy.

METHODS

An RCT was conducted from May 2015 to June 2018. The primary endpoint was duration of hospital stay. Secondary endpoints were intraoperative technical events and postoperative clinical outcomes.

RESULTS

A total of 140 patients were randomized. Duration of surgery was longer for procedures with an IA than in those with an EA (median 149 (range 95-215) versus 123 (60-240) min; P < 0·001). Wound length was shorter in the IA group (median 6·7 (4-9·5) versus 8·7 (5-13) cm; P < 0·001). Digestive function recovered earlier in patients with an IA (median 2·3 versus 3·3 days; P = 0·003) and the incidence of paralytic ileus was lower (13 versus 30 per cent; P = 0·022). Less postoperative analgesia was needed in the IA group (mean(s.d.) weighted analgesia requirement 39(24) versus 53(26); P = 0·001) and the pain score was also lower (P = 0·035). The postoperative decrease in haemoglobin level was smaller (mean(s.d.) 8·8(1·7) versus 17·1(1·7) mg/dl; P = 0·001) and there was less lower gastrointestinal bleeding (3 versus 14 per cent; P = 0·031) in the IA group. IA was associated with a significantly better rate of grade I and II complications (P = 0·016 and P = 0·037 respectively). The duration of hospital stay was slightly shorter in the IA group (median 5·7 (range 2-19) versus 6·6 (2-23) days; P = 0·194).

CONCLUSION

Duration of hospital stay was similar, but IA was associated with less pain and fewer complications. Registration number: NCT02667860 ( http://www.clinicaltrials.gov).

Intracorporeal versus extracorporeal anastomosis in right hemicolectomy assisted by laparoscopy: study protocol for a randomized controlled trial

BACKGROUND

Colorectal cancer (CRC) is the third most frequent cancer diagnosed in men and the second in women. Laparoscopic surgery has been a technical revolution in colorectal surgery, facilitating a better recovery of patients with lower morbidity and better esthetic results, compared to traditional surgery via laparotomy, without compromising safety and long-term oncological results.

PURPOSE

The trial is a randomized controlled trial indented to evaluate the two interventions with thorough measurements of the postoperative variables and complications to improve the evaluation of the surgical technique. The primary endpoint is to compare the hospital stay, which will be measured in days between both groups. The purpose of the study at secondary endpoints is to compare intraoperative and postoperative events between both groups in terms of operating time, anastomotic performance time, intraoperative complications, number of harvested lymph nodes, need for blood transfusion, length of the surgical wound, start and tolerance of oral intake, beginning of digestive functionality, postoperative pain, need for analgesic administration, surgical wound infection, paralytic ileus, anastomosis leakage or dehiscence, need for surgical reintervention, and hospital readmission within the first 30 days after surgery.

METHODS

This trial is a prospective, randomized, single-blind, and single-center clinical trial comparing intracorporeal anastomosis versus extracorporeal anastomosis for right laparoscopic hemicolectomy.

CONCLUSIONS

Nowadays, there are several retrospective trials comparing the benefits for extracorporeal anastomosis versus intracorporeal anastomosis in right colon cancer patients. Considering the impact for laparoscopic surgery, we think it is necessary to do a randomized trial comparing extracorporeal versus intracorporeal anastomosis modalities.

TRIAL REGISTRATION

www.clinicaltrials.gov No. NCT02667860 and Hospital de la Santa Creu i Sant Pau Research Institute No. IIBSP-AIE-2015-01.

Impact of TGF-β family-related growth factors on chondrogenic differentiation of adipose-derived stem cells isolated from lipoaspirates and infrapatellar fat pads of osteoarthritic patients

The success of cell-based approaches for the treatment of cartilage defects requires an optimal autologous cell source with chondrogenic differentiation ability that maintains its differentiated properties and stability following implantation. The objective of this study was to compare the chondrogenic capacity of mesenchymal stem cells (MSCs) isolated from lipoaspirates (ASCs) and the infrapatellar fat pad (IFPSCs) of osteoarthritic patients and treated with transforming growth factor (TGF)-β family-related growth factors. Cells were cultured for 6 weeks in a 3D pellet culture system with the chimeric activin A/bone morphogenic protein (BMP)-2 ligand (AB235), the chimeric nodal/BMP-2 ligand (NB260) or BMP-2. To investigate the stability of the new cartilage, ASCs-treated pellets were transplanted subcutaneously into severe combined immunodeficiency (SCID) mice. Histological and immunohistochemical assessment confirmed that the growth factors induced cartilage differentiation in both isolated cell types. However, reverse transcription-quantitative PCR results showed that ASCs presented a higher chondrogenic potential than IFPSCs. In vivo results revealed that AB235-treated ASCs pellets were larger in size and could form stable cartilage-like tissue as compared to NB260-treated pellets, while BMP-2-treated pellets underwent calcification. The chondrogenic induction of ASCs by AB235 treatment was mediated by SMAD2/3 activation, as proved by immunofluorescence analysis. The results of this study indicated that the combination of ASCs and AB235 might lead to a cell-based cartilage regeneration treatment.

Stress-related hormonal alterations, growth and pelleted starter intake in pre-weaning Holstein calves in response to thermal stress

This study aimed to investigate the effect of heat stress and month of birth on growth performance, pelleted starter intake, and stress-related hormones in Holstein calves. Birth weight and growth records, representing 4735 Holstein calves from a large commercial dairy herd in northern Mexico (25° N; 22.3 °C mean annual temperature) from 2013 to 2015, were analyzed. Temperature-humidity index (THI) at calving, season of birth, and month of birth were the independent variables, whereas growth traits were the dependent variables. Increased THI at birth from < 65 to > 85 units was associated with a decrease in birth weight from 39.3 to 38.7 kg. Calves subjected to high THI (> 75 units) at calving showed lesser (P < 0.01) pre-weaning gains (405 ± 97 g/calf/day), whereas those calves born with THI < 70 units presented the highest gains (466 ± 112 g/calf/day). Birth during the fall months reduced (P < 0.01) weaning weight by about 5 kg compared with winter months. Also, the pre-weaning average daily gain for calves born in the fall was about 70 g less (P < 0.01) than calves delivered in winter months. Plasma triiodothyronine and tetraiodothyronine levels were lower (1.02 ± 0.21 and 48 ± 7.9 ng/mL, respectively; P < 0.01) in summer and highest in winter (1.64 ± 0.48 and 66 ± 11 ng/mL, respectively). Mean plasma cortisol concentration was higher in heat-stressed calves born in summer (59 ± 40 ng/mL) than calves born in winter (20 ± 28 ng/mL). Pelleted starter intake 1 week before weaning was lowest (P < 0.01) in the fall (0.82 ± 0.26 kg/calf/day; mean ± SD) and highest in spring (1.26 ± 0.43 kg/calf/day). It was concluded that in this particular environment, heat stress affects birth weight and growth rate of Holstein calves. Thus, environmental management of the newborn calf during hot spring and summer months is warranted to optimize pelleted starter intake and calf growth rates.

Asymptomatic carriers of Leishmania infantum in patients infected with human immunodeficiency virus (HIV) in Morocco

In Morocco, visceral leishmaniasis (VL) is a parasitic disease caused by the flagellated protozoan parasite Leishmania infantum. L. infantum is transmitted by the bite of female phlebotomine sandflies, and its main reservoir hosts are domestic dogs. Asymptomatic infection with L. infantum is more frequent than clinically apparent disease. In HIV-infected patients, the risk of clinical VL is increased due to immunosuppression that may reactivate latent infections. However, coinfected subjects do not necessarily develop VL and may remain as asymptomatic carriers depending on their immune status. The present study investigates the asymptomatic carriers of L. infantum in HIV-infected patients in central Morocco, where human cases of visceral leishmaniasis by L. infantum have been reported. A total of 200 HIV-infected patients attending the Infectious Diseases Unit of the Ibn Zohar Hospital of Marrakech participated in the study. Parasitological and serological blood analyses included a direct microscopic examination (DME), culture in Novy-McNeal-Nicolle (NNN) medium, and serology by indirect immunofluorescence (IFI). We found prevalence rates of 5% (10/200) by IFI, 3% (6/200) by DME, and 2.5% (5/200) by culture. The parasite was identified as L. infantum by PCR from positive cultures.

Cytokines and chemokines measured in dried SLA-stimulated whole blood spots for asymptomatic Leishmania infantum and Leishmania donovani infection

Whole blood stimulation with soluble Leishmania antigen (SLA), followed by plasma cytokine and chemokine determination, provides means of detecting subjects with asymptomatic Leishmania infection. This work examines the potential of Protein Saver 903 cards for the storage and transport of SLA-stimulated dried plasma spot samples. Blood was collected from asymptomatic and negative control subjects living in a Leishmania infantum- (Spain) and Leishmania donovani-endemic area (Bangladesh). After SLA-stimulation, three types of sample were prepared: frozen liquid plasma (-20 °C), and plasma dropped onto Protein Saver cards kept at -20 °C (DPS-FZ), and at ambient temperature (DPS-AT). The concentrations of IFN-γ, IL-2, CXCL10, CXCL9, CCL2 and CXCL8 in the thawed liquid plasma (TLP), DPS-FZ and DPS-AT samples were then determined. Strong correlations were seen between the TLP and DPS-FZ/AT samples for all the studied cytokines/chemokines in both the L. infantum and L. donovani areas. Protein Saver 903 cards would therefore appear to allow for the transport of SLA-stimulated plasma samples by courier at ambient temperature. The CXCL10 and CXCL9 detectable in these plasma spots provided robust markers for identifying asymptomatic subjects from both endemic areas. This easy procedure opens up new possibilities for field studies in resource-limited settings, which could help in Leishmania control.

Nursing workload and adherence to non-pharmacological measures in the prevention of ventilator-associated pneumonia. A pilot study

OBJECTIVE

To analyse whether adherence to non-pharmacological measures in the prevention of ventilator-associated pneumonia (VAP) is associated with nursing workload.

METHODS

A prospective observational study performed in a single medical-surgical ICU. Nurses in charge of patients under ventilator support were assessed.

VARIABLES

knowledge questionnaire, application of non-pharmacological VAP prevention measures, and workload (Nine Equivalents of Nursing Manpower Use Score). Phases: 1) the nurses carried out a educational programme, consisting of 60-minute lectures on non-pharmacological measures for VAP prevention, and at the end completed a questionnaire knowledge; 2) observation period; 3) knowledge questionnaire.

RESULTS

Among 67 ICU-staff nurses, 54 completed the educational programme and were observed. A total of 160 observations of 49 nurses were made. Adequate knowledge was confirmed in both the initial and final questionnaires. Application of preventive measures ranged from 11% for hand washing pre-aspiration to 97% for the use of a sterile aspiration probe. The Nine Equivalents of Nursing Manpower Use Score was 50±13. No significant differences were observed between the association of the nurses' knowledge and the application of preventive measures or between workload and the application of preventive measures.

CONCLUSIONS

Nurses' knowledge of VAP prevention measures is not necessarily applied in daily practice. Failure to follow these measures is not subject to lack of knowledge or to increased workload, but presumably to contextual factors.

Interleukin-2 as a marker for detecting asymptomatic individuals in areas where Leishmania infantum is endemic

No field method exists for identifying asymptomatic individuals in areas where Leishmania infantum is endemic. This work reports that, 24 h after stimulating whole blood with soluble Leishmania antigen (SLA), plasma interferon-γ (IFN-γ) and interleukin-2 (IL-2) become significantly elevated in samples from asymptomatic individuals (n=47) compared with those from negative controls (n=50), all of them recruited from a blood bank. When compared with the reference test SLA-lymphoproliferative assay, IL-2 appears as a new, 100% sensitive and specific marker for asymptomatic individuals with a positive cellular response (compared with 100% and 84.78%, respectively, for IFN-γ). Further studies in other transmission areas and in other cohorts of exposed people need to be performed to confirm these results. Once validated, IFN-γ and IL-2 levels in SLA-stimulated whole blood could be reliably used in the field to estimate the prevalence of those asymptomatic individuals with Leishmania-specific cellular immune responses.

Reproductive outcomes of Alpine goats primed with progesterone and treated with human chorionic gonadotropin during the anestrus-to-estrus transition season

This study aimed to determine the possible effects of a single injection of human chorionic gonadotropin (hCG) as a means for estrus induction in acyclic French-Alpine goats during the reproductive transition period at 25°N, 103°W. The potential effects of hCG upon ovarian function and reproductive performance of goats were also assessed. Multiparous acyclic French-Alpine goats (n = 39; 37.4 ± 8 .5 kg) were primed with 20mg progesterone (P4) 1 day prior to hCG administration. Thereafter, does were treated either with saline (hCG-0; n = 10), 50 (hCG-50; n = 9), 100 (hCG-100; n = 10), or 300 IU of hCG (hCG-300; n = 10). Ovarian structures and pregnancy were monitored by transrectal ultrasonography. In addition, after hCG application, goats were monitored twice daily (0800 and 1800 h) to detect estrus signs, with the use of aproned, sexually active bucks treated with testosterone. Goats were bred 12h after the onset of estrus. Two days after hCG administration, the number of large follicles was higher (P < 0.05) in the hCG-50 and hCG-300 groups (1.7 ± 0.1 and 1.8 ± 0.2, respectively) compared with the hCG-100 and hCG-0 groups (1.4 ± 0.2 and 1.1 ± 0.1, respectively). Although none of the hCG-0-goats depicted estrus, the estrus response from the hCG-50, hCG-100, and hCG-300 groups over the 7-d breeding period was 67%, 100%, and 90%, respectively (P > 0.05), being always accompanied by ovulation. Pregnancy rate (67, 100, and 70%), kidding rate (55%, 80%, and 70%), and litter size (1.6 ± 0.5, 1.5 ± 0.5, and 1.5 ± 0.5) for hCG-50, hCG-100, and hCG-300, respectively, did not differ among the hCG-treated does. Therefore, the combined use of P4-priming plus a 100-IU hCG injection is an effective protocol for inducing estrus in non-cycling Alpine goats during the anestrus-to-estrus transition period, which is of key importance for both goat producers and industrializers.

Improvement over the years of long-term survival in high-risk lymphoma patients treated with hematopoietic stem cell transplantation as consolidation or salvage therapy

The role of hemopoietic stem cell transplantation (HSCT) is not well established in certain types of lymphoma, such as those with a high relapse risk or relapsing after initial therapy. New chemotherapeutic schemes and immunotherapy have improved survival of these patients. Nevertheless, there is not enough evidence regarding whether transplantation is the best therapeutic approach. Moreover, published data on long-term follow-up of high-risk lymphoma patients treated with HSCT are scarce. We analyzed 177 consecutive patients diagnosed with a high risk of relapse or with relapsed lymphoma who underwent HSCT after induction with standard chemotherapy in a tertiary academic center from 1989 to 2013. The median age was 40 years. Diagnoses were Hodgkin disease (n = 56), diffuse large B-cell lymphoma (n = 44), follicular lymphoma (n = 29), mantle cell lymphoma (n = 15), T-cell lymphoma (n = 18), and others (n = 15). Patients received either an autologous graft (n = 154) in first complete remission (1CR; n = 59) or more advanced stages (AS; n = 95), or an allogeneic graft (n = 23) in 1CR (n = 4) or AS (n = 19). In the autologous group, overall survival (OS) at 5 years was 57% and 75% in the periods 1989-2001 and 2002-2013, respectively (P = .05). Patients receiving an allogeneic graft presented an OS of 25% and 43% in the 2 periods. With a mean follow-up of 5 years (95% confidence interval 3.5-6.6), for patients receiving a transplant in 1CR, OS at 5 years was 80%, and for those receiving a transplant in AS it was 59% (P = .003). Nonrelapse mortality (NRM) at 5 years was 3.1% in the autologous group and 27.9% in the allogeneic group (P < .001). The main cause of NRM was infection (44%) in the whole cohort. All this leads to the conclusion that transplantation, as a therapeutic strategy, has shown a high long-term OS in this subgroup of patients with such a poor prognosis. OS improved over the years and reaching 1CR was a good prognostic feature. Infections were the main cause of NRM.

Identification of quantitative trait loci and candidate genes for specific cellular resistance responses against Didymella pinodes in pea

KEY MESSAGE

Phenotyping of specific cellular resistance responses and improvement of previous genetic map allowed the identification of novel genomic regions controlling cellular mechanisms involved in pea resistance to ascochyta blight and provided candidate genes suitable for MAS. Didymella pinodes, causing ascochyta blight, is a major pathogen of the pea crop and is responsible for serious damage and yield losses. Resistance is inherited polygenically and several quantitative trait loci (QTLs) have been already identified. However, the position of these QTLs should be further refined to identify molecular markers more closely linked to the resistance genes. In previous works, resistance was scored visually estimating the final disease symptoms; in this study, we have conducted a more precise phenotyping of resistance evaluating specific cellular resistance responses at the histological level to perform a more accurate QTL analysis. In addition, P665 × Messire genetic map used to identify the QTLs was improved by adding 117 SNP markers located in genes. This combined approach has allowed the identification, for the first time, of genomic regions controlling cellular mechanisms directly involved in pea resistance to ascochyta blight. Furthermore, the inclusion of the gene-based SNP markers has allowed the identification of candidate genes co-located with QTLs and has provided robust markers for marker-assisted selection.

Regulatory systems in bone marrow for hematopoietic stem/progenitor cells mobilization and homing

Regulation of hematopoietic stem cell release, migration, and homing from the bone marrow (BM) and of the mobilization pathway involves a complex interaction among adhesion molecules, cytokines, proteolytic enzymes, stromal cells, and hematopoietic cells. The identification of new mechanisms that regulate the trafficking of hematopoietic stem/progenitor cells (HSPCs) cells has important implications, not only for hematopoietic transplantation but also for cell therapies in regenerative medicine for patients with acute myocardial infarction, spinal cord injury, and stroke, among others. This paper reviews the regulation mechanisms underlying the homing and mobilization of BM hematopoietic stem/progenitor cells, investigating the following issues: (a) the role of different factors, such as stromal cell derived factor-1 (SDF-1), granulocyte colony-stimulating factor (G-CSF), and vascular cell adhesion molecule-1 (VCAM-1), among other ligands; (b) the stem cell count in peripheral blood and BM and influential factors; (c) the therapeutic utilization of this phenomenon in lesions in different tissues, examining the agents involved in HSPCs mobilization, such as the different forms of G-CSF, plerixafor, and natalizumab; and (d) the effects of this mobilization on BM-derived stem/progenitor cells in clinical trials of patients with different diseases.

Differential cytogenetic profile in advanced chronic myeloid leukemia with sequential lymphoblastic and myeloblastic blast crisis

Frequency of additional chromosomal abnormalities in chronic myeloid leukemia (CML) is estimated to be 7% in chronic phase and increases to 40–70% in advanced disease. Progression of CML from chronic phase to accelerated phase or blast crisis is often associated with secondary chromosomal aberrations. We report an exceptional case of CML as debut in lymphoblastic blast crisis and a subsequent progression in myeloblastic blast crisis with rare cytogenetic abnormalities.

How is gene transfection able to improve current chemotherapy? The role of combined therapy in cancer treatment

Despite advances in cancer treatment, a large number of patients eventually develop metastatic disease that is generally incurable. Systemic chemotherapy remains the standard treatment for these patients. Several chemotherapeutic combinations have proven effective in the management of cancer. Paradoxically, although the purpose of polychemotherapy is to improve the prognosis and prolong the survival of patients, it often carries considerable toxicity that causes substantial adverse symptoms. For this reason, a major goal of cancer research is to improve the effectiveness of these cytotoxic agents and reduce their adverse effects. Gene transfer has been proposed as a new strategy to enhance the efficacy of anti-tumor drugs in the treatment of intractable or metastatic cancers. In fact, the association of gene therapy and drugs (combined therapy) has been reported to increase the anti-proliferative effect of classical treatments in lung, bladder, pancreatic, colorectal and breast cancers, among others. Various especially promising therapies have been proposed in this context, including the use of suicide genes, antisense oligonucleotides, ribozymes and RNA interference. In this chapter, we review recent progress in the development of novel anti-cancer strategies that associate cytotoxic agents with gene transfer to enhance their antitumor effect.

Influence of nutritional knowledge on the use and interpretation of Spanish nutritional food labels

The present study analyzed the nutritional knowledge of Spanish consumers and its relationship with the correct use of food labels. Consumers were asked about their nutritional knowledge and some functional foods and about their understanding of food labeling and their use of it to select healthy food. A 2-part questionnaire was employed. The 1st part concerned their knowledge of nutritional facts, including their knowledge about macronutrients and perception of certain functional foods, while the 2nd part addressed some questions regarding food labels. The results revealed no statistically significant differences in nutritional knowledge by either age or gender, but a direct relationship with educational level. The association between nutritional knowledge and the perception and understanding of food labeling showed that the nutritional label rarely influenced the food purchases of the group with low nutritional knowledge, who considered that this information was too technical. More than half of the consumers did not consider the calorie or sugar content important for selecting food. In addition, the group with low nutritional knowledge stated that they never or rarely looked at the food labels to check whether it was low-fat food that they were buying.

PRACTICAL APPLICATION

Knowing the status of the consumer's nutritional knowledge allows health campaigns to be designed; considering the influence of cultural factors and the perception of food labeling is very useful for promoting better nutritional information.

Tumour malignancy loss and cell differentiation are associated with induction of gef gene in human melanoma cells

BACKGROUND

Gene therapy is a new method used to induce cancer cell differentiation. Our group previously showed that transfection of the gef gene from Escherichia coli, related to cell-killing functions, may be a novel candidate for cancer gene therapy. Its expression leads to cell cycle arrest unrelated to the triggering of apoptosis in MS-36 melanoma cells.

OBJECTIVES

To determine the basis of the antiproliferative effect of the gef gene in this cell line.

METHODS

Transmission electron microscopy, apoptosis analysis by confocal microscopy, flow cytometry and immunocytochemical analysis were used.

RESULTS

Ultrastructural analysis showed a strikingly different morphology after treatment with dexamethasone and expression of the gef gene, with large accumulations of pigment throughout the cell cytoplasm and presence of melanosomes in different stages of development. High mitochondrial turnover and myeloid bodies, characteristics of neurone cells, were also observed. In addition, both immunocytochemical and indirect immunofluorescence analysis demonstrated a significant decrease in HMB-45, Ki-67 and CD44 antigen expression and an increase in S100 and p53 expression in gef gene-transfected MS-36 melanoma cells that were correlated with the duration of dexamethasone treatment. In the present work, we report that gef gene not only reduces cell proliferation in transfected melanoma MS-36TG cell line but also induces morphological changes clearly indicative of melanoma cell differentiation and a reduction in tumour malignancy.

CONCLUSIONS

These findings support the hypothesis that the gef gene offers a new approach to differentiation therapy in melanoma.

Immunization with H1, HASPB1 and MML Leishmania proteins in a vaccine trial against experimental canine leishmaniasis

The protective capabilities of three Leishmania recombinant proteins – histone 1 (H1) and hydrophilic acylated surface protein B1 (HASPB1) immunized singly, or together as a protein cocktail vaccine with Montanide™, and the polyprotein MML immunized with MPL^®-SE adjuvant – were assessed in beagle dogs. Clinical examination of the dogs was carried out periodically under blinded conditions and the condition of the dogs defined as asymptomatic or symptomatic. At the end of the trial, we were able to confirm that following infection with L. infantum promastigotes, five out of eight dogs immunized with H1 Montanide™, and four out of eight dogs immunized with either the combination of HASPB1 with Montanide™ or the combination of H1 + HASPB1 with Montanide™, remained free of clinical signs, compared with two out of seven dogs immunized with the polyprotein MML and adjuvant MPL^®-SE, and two out of eight dogs in the control group. The results demonstrate that HASPB1 and H1 antigens in combination with Montanide™ were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions.

Immunogenicity of the P-8 amastigote antigen in the experimental model of canine visceral leishmaniasis

The P-8 proteoglycolipid complex (P-8 PGLC), an amastigote antigen of Leishmania pifanoi, has been demonstrated to induce protection in mouse models, as well as to induce Tc1/Th1-like cellular responses in American cutaneous leishmaniasis patients. Because the immunization with P-8 PGLC in the murine model does not appear to be genetically restricted, we have studied the reactivity of the P-8 PGLC in Leishmania infantum infected dogs. In this study, it is shown that PBMC from experimentally infected dogs (asymptomatic, oligosymptomatic) significantly proliferated in response to soluble leishmanial antigen (SLA) or the P-8 PGLC. Further, quantification of the gene expression induced by the stimulation with P-8 in asymptomatically infected dogs showed an up-regulation of IFN-gamma and TNF-alpha, which were three to 4-fold higher than that induced by soluble Leishmania antigen (SLA). While no measurable induction of IL-10 was observed, low levels of IL-4 mRNA were observed in response to both P-8 and SLA antigens. Thus, our studies establish that P-8 is recognized by infected canines and elicits a potentially curative/protective Th1-like immune response. The identification of Leishmania antigens that elicit appropriate immune responses across different host species (humans, canine) and disease manifestations (cutaneous or visceral) could be an advantage in generating a general vaccine for leishmaniasis.

Induction of drug resistance in embryonal rhabdomyosarcoma treated with conventional chemotherapy is associated with HLA class I increase

Effectiveness of conventional cytotoxic treatment of rhabdomyosarcoma (RMS) may be limited by the development of multidrug resistance (MDR) mediated by mdr1 gene. This gene codes for P-glycoprotein (P-gp) which has been related to a immunoregulatory function. Modulation of HLA expression by P-gp has been described in different types of tumor cells including RMS. However, very little is known about biological implications of the P-gp expression in RMS patients treated with conventional chemotherapy. In order to study the problem, we used embryonal RMS tissue samples from treated patients. Our results indicated that positive RMS samples to mdr1 show higher HLA class I expression than those which were negative to mdr1 PCR, what indicates a significant correlation between the expression of both molecules. In addition, we developed two resistant RMS cell lines (A-204-1 and 2) using similar concentrations of actinomycin D as are plasma levels in clinical situation. Both resistant cell lines showed mdr1 expression and an increase of HLA class I expression which was dose-dependent. These results demonstrated that conventional chemotherapy of embryonal RMS is able to induce resistance which can modulate HLA class I expression and suggest that immunological studies of these tumors may be necessary to the design new specific therapeutic strategies.

Modulation of Ki-67 expression and morphological changes induced by gef gene in MCF-7 human breast cancer cells

New therapeutic strategies are required to overcome the limitations of conventional breast cancer treatment. Suicide gene therapy offers a potential approach to this type of tumour, since systems based on the use of prodrugs may present some drawbacks related to toxicity, drug release and bioavailability. The gef gene has cell-killing functions in Escherichia coli and does not depend on the use of a prodrug for its action, making it an attractive target for suicide gene therapy. We created a gef-overexpressing human breast cancer cell line (MCF-7TG) by transfecting the gef gene under the control of a pMAMneo promotor. Dexamethasone-induction of gef gene expression in MCF-7TG cells produced a significant decrease in Ki-67 expression, which is a known proliferation marker. In addition, annexin-V-FITC and propidium iodide assays showed the presence of apoptotic cell death, which was confirmed by scanning electron microscopy. The most significant finding was the presence of "craters" in the cell membrane, as previously described in other apoptotic breast cancer cells. These results demonstrate the ability of the gef gene to down regulate Ki-67 expression and induce apoptosis in a breast cancer cell line, suggesting its potential application as a new gene therapy strategy for this type of tumor.

Regulation of muscle Cav1.1 channels by long-term depolarization involves proteolysis of the alpha1s subunit

The effects of long-term depolarization on frog skeletal muscle Cav1.1 channels were assessed. Voltage-clamp and Western-blot experiments revealed that long-term depolarization brings about a drastic reduction in the amplitude of currents flowing through Cav1.1 channels and in the levels of the alpha1s subunit, the main subunit of muscle L-type channels. The decline of both phenomena was prevented by the action of the protease inhibitors E64 (50 microM) and leupeptin (50 microM). In contrast, long-term depolarization had no effect on beta1, the auxiliary subunit of alpha1s. The levels of mRNAs coding the alpha1s and the beta1 subunits were measured by RNase protection assays. Neither the content of the alpha1s nor the beta1 subunit mRNAs were affected by long-term depolarization, indicating that the synthesis of Cav1.1 channels remained unaffected. Taken together, our experiments suggest that the reduction in the amplitude of membrane currents and in the alpha1s subunit levels is caused by increased degradation of this subunit by a Ca2+-dependent protease.

Contractile Regulatory Proteins Tropomyosin and Troponin-T as Indicators of the Modulatory Role of Retinoic Acid

Retinoic acid (RA), the active metabolite of vitamin A, plays a significant role in regulating cardiac form and function throughout the life of the organism. Both cardiac morphogenesis and myocardial differentiation are affected by alterations in RA homeostasis. In order to test the effect of all-trans RA and 13-cis RA on cardiomyocyte differentiation, we studied the level and the subcellular compartmentalization of alpha-tropomyosin and troponin-T proteins in cultures of chick embryo cardiomyocytes obtained from Hamburger and Hamilton's (HH) stage 22, 32 and 40 embryos. The retinoids increased the levels of alpha-tropomyosin and troponin-T in the cytoplasmic and cytoskeletal fractions of cells at all three stages of development. The greatest increases in alpha-tropomyosin occurred in the cytoplasmic fraction in HH22 cells cultured for 24 h with all-trans RA or 13-cis RA, whereas the greatest increases in troponin-T were found in the cytoplasmic fraction of HH32 cells exposed to retinoids for 24 h. In cultures treated for 48 h with retinoids, the levels of alpha-tropomyosin and troponin-T showed significant increases in the cytoplasmic compartment of cells treated in HH32-with respect to the control values. These findings are further evidence that RA plays a modulating role in the formation and reorganization of sarcomeric proteins during the process of cardiomyocyte maturation.

Modulation of HLA class I expression in multidrug-resistant human rhabdomyosarcoma cells

An abnormal HLA expression has been detected in some tumors including rhabdomyosarcoma (RMS). Classical cytotoxic treatment of these tumors, the most common childhood soft tissue malignancy, may induce multidrug resistance (MDR) associated with the expression of a 170-kDa membrane-associated glycoprotein (P-glycoprotein). In order to analyse the connection between modulation of HLA expression and the development of the MDR phenotype mediated by P-glycoprotein in RMS, we used three resistant RMS cell lines; two of these resistant cell lines (TE.32.7.DAC and RD-DAC) were established by in vitro exposure to actinomycin D, a drug of choice in the treatment of RMS; the resistant RMS- GR cell line was established from an embryonal RMS tumor after polychemotherapy. Our results showed that all the resistant cell lines showed a significant increase in the expression of HLA class I surface antigens in comparison to drug-sensitive cells. Blockade of P-glycoprotein with verapamil led to a decrease in HLA class I expression in RMS resistant cell lines. However, no modulation of HLA class II expression was observed in any of the three analyzed cell lines. These findings support the hypothesis that the development of resistance mediated by mdr 1/P-glycoprotein, directly influences the expression of HLA class I in RMS cells, inducing to upregulation. This effect may be relevant to the application in RMS of immunotherapy against tumor-associated antigens presented by HLA class I molecules.

Inhibition of growth and induction of apoptosis in human breast cancer by transfection of gef gene

The gef gene has cell-killing functions in Escherichia coli. To evaluate the feasibility of using this gene as a new strategy for cancer therapy, we transfected it in MCF-7 cells derived from breast cancer (MCF-7TG). The gef gene was cloned in a pMAMneo vector under the control of a mouse mammary tumour virus promoter, inducible by dexamethasone (Dex), and was transfected with liposomes. After selection and induction, expression of the gef gene was confirmed by reverse transcription-polymerase chain reactions (RT-PCR) and Western blot. Cell viability was determined with a haemocytometre and the sulphorodamine B colorimetric assay, and the cell cycle was studied by propidium iodide (PI) staining. Annexin V-FITC and PI assays were used to evaluate apoptosis, which was confirmed by electron microscopy. In comparison with MCF-7 parental cells and MCF-7 cells transfected with an empty vector, MCF-7TG cells induced with Dex showed a significant decrease in proliferation rate, which was associated with evidence of apoptosis. Morphological findings confirmed apoptosis and showed a typical pattern of mitochondrial dilation. Furthermore, the cell cycle was characterised by premature progression from G(1) to S phase and G(2) delay. Our results show that the gef gene was able to decrease proliferation in a breast cancer cell line, and induce apoptosis. These findings suggest that the gef gene is a potential candidate for tumour therapy.

Gender differences in cardiovascular and electrodermal responses to public speaking task: the role of anxiety and mood states

Gender moderates psychophysiological responses to stress. In addition to the hormonal background, different psychological states related to social stressors, such as anxiety and mood, could affect this response. The purpose of this study was to examine the existence of gender differences in the cardiovascular and electrodermal responses to a speech task and their relationship with anxiety and the mood variations experienced. For this, non-specific skin conductance responses (NSRs), heart rate (HR), and finger pulse volume (FPV) were measured at rest, and during preparation, task and recovery periods of an academic career speech in undergraduate men (n=15) and women (n=23), with assessment of changes in the state version of the State-Trait Anxiety Inventory (STAI-S) and in the Profile of Mood States (POMS) questionnaires. Men and women did not differ in trait anxiety, hostility/aggressiveness, or in the appraisal of the task, which were evaluated with the trait version of the State-Trait Anxiety Inventory (STAI-T), the Buss and Durkee Hostility Inventory (BDHI), and a self-report elaborated by ourselves, respectively. Women had higher FPV in all periods except during the task, and were more reactive to the stressor in state anxiety, and in the amplitude of NSRs. No gender differences for HR and for the frequency of NSRs were found. Anxiety and mood states were differently related to cardiovascular and electrodermal measurements in men and women. Further studies should consider the hormonal variations in addition to the psychological dimensions, in order to offer a more integrative perspective of the complex responses to stress.

White-lipped peccary (Tayassu pecari, Artiodactyla: Tayassuidae) diet and fruit availability in a Costa Rican rain forest

We studied fruit availability, diet and habitat use by white-lipped peccary (Tayassu pecari) in Corcovado National Park, southwest Costa Rica, from July 1996 to April 1997. The results show that the availability of important fruits for the white-lipped peccary differs between habitats and climatic seasons. Fruit availability was highest in the primary forest than secondary and coastal forest. There was a period of shortage of fruits to ends of the wet season, during which the consumption of not seasonal resources like leaves and shafts increased. The important fruits during this period of shortage were Ficus sp and Licania operculipetala. The several types of forest were used according to the fruit availability, and it was a direct relation between the consumption and the fruit availability.

Induction of sexual activity of male creole goats in subtropical northern Mexico using long days and melatonin

The aim of this study was to determine whether the sexual activity of local male Creole goats in subtropical Mexico can be induced during the non-breeding season by a long-day treatment followed by insertion of two melatonin implants. The experiment was carried out in the Laguna region in the State of Coahuila, Mexico (26 degrees N). Fourteen male goats were allocated to two balanced groups (n = 7 each) according to body and testicular weights. Males were kept together in two separate groups and fed lucerne hay for ad libitum intake and 300 g of commercial concentrate and had free access to water and mineral blocks. The control group remained in open sheds under natural photoperiod and ambient temperature conditions. The experimental group was placed in a light-proof building and exposed to 2.5 mo of long days (16 h of light/d) from November 1 to January 15. On January 16, each male received two s.c. melatonin implants and was exposed to natural photoperiodic changes in an open shed. In the control group, testicular weight exhibited seasonal variations; the highest value occurred on May 30 (146 +/- 10 g). Treated males reached maximum testicular weight earlier (March 15; 147 +/- 11 g), and sperm quality from January to March was higher than that observed in the control group (P < 0.05). Treatment caused an increase in LH pulse frequency (2.0 +/- 0.5 vs 0.3 +/- 0.2 pulse/8 h in February, 4.6 +/- 1.1 vs 0.1 +/- 0.1 pulse/8 h in March; experimental vs control group, respectively). In the control group, plasma testosterone remained low until mid-June and increased thereafter to remain elevated until the end of the study. In the experimental group, elevated plasma testosterone was observed from February to April and from July to November. Treating male goats in subtropical latitudes with artificial long days and melatonin can induce an intense sexual activity during the natural nonbreeding season.