HLA-G: Function, polymorphisms and pathology

HLA-G immune modulatory genes and molecules are presently being studied by a widespread number of research groups. In the present study, we do not aim to be exhaustive since the number of manuscripts published every year is overwhelming. Instead, our aim is pointing out facts about HLA-G function, polymorphism and pathology that have been confirmed by several different researchers, together with exposing aspects that may have been overlooked or not sufficiently remarked in this productive field of study. On the other hand, we question whether performing mainly studies on HLA-G and disease associations is going to give a clear answer in the future, since 40 years of study of classical HLA molecules association with disease has still given no definite answer on this issue.

HLA genes in Amerindians from Mexico San Vicente Tancuayalab Teenek/Huastecos

Huastecos or Teenek Amerindians are presently living at North East Mexico (San Luis Potosi State). They have probably one of the most ancient culture of Mexico and Central America together with Mayas and Olmec groups with which also show close relationships. Proximity to Atlantic Ocean/Mexican Gulf originated that Spaniards had very early contact with them at about 1519 CE or before. In the present paper we have aimed to study HLA gene profile which may be useful for HLA and disease epidemiology and transplant programs in Teeneks. HLA-DRB1*04:07, -DRB1*14:06 and -DRB1*04:11 have been found in high frequency like in other Amerindian groups. High frequency typical Amerindians HLA extended haplotypes have been found, such as A*02-B*35-DRB1*04:07-DQB1*03:02; A*68-B*39-DRB1*04:07-DQB1*03:02 and A*02-B*39-DRB1*04:07-DQB1*03:02; also new haplotypes have been described, like A*02-B*52-DRB1*04:11-DQB1*03:02, A*68-B*35-DRB1*14:02-DQB1*03:01 and A*68-B*40-DRB1*16:02-DQB1*03:01. Genetic proximity is observed not only to linguistically close Mayans, but also to Mazatecans, Mixtecans and Zapotecans, who speak an altogether different languages; it shows once more that genes and languages do not correlate. This population was greatly diminished after European contact between 1500 and 1600 years CE; in fact, North and South America First Inhabitants population was brought from 80 down to 8 million people because of diseases (i.e.: measles, smallpox or influenza), slavery and war.

Frequencies and significance of HLA genes in Amerindians from Chile Cañete Mapuche

Mapuche Amerindians live now widespread in Central South Chile and Argentina and speak "Mapudungun", an unclassified language. A group of Chilean Mapuche was studied for HLA genes using standard techniques. Typical Amerindian HLA genes and haplotypes are found in the population, like HLA-DRB1*14:02, -08:02 and class II haplotype DRB1*08:02-DQB1*04:02. However, these and other genes are also common in Pacific Islanders. Thus, relatedness of First America Inhabitants with some Pacific Islanders is stressed. Evidences of Pacific and Atlantic cultural and genetic exchange, probably in both directions, and California Man settlements found since 130,000 years ago makes it necessary a revision of Americas peopling. This study may be also useful for medical Mapuche use in Transplantation and HLA and disease Epidemiology.

Reduction of negative social attributions towards people with mental illness through a combination of treatments

Introduction

Stigma towards people with mental illness can have very negative consequences for the persons that experience it. So, it becomes strongly necessary to combat this problem.

Objectives/Aims

Evaluate the effectiveness of multiple interventions to reduce stigma against mental illness in a group of high school students.

Methods

Quasi-experimental study. Seventy-six students between 16 to 19 years old from 3 schools of southern Madrid State participated. No significant differences in age and gender between groups were found. The quasi-control group was obtained from 3 different classrooms (1 in each school). This group did not go through any treatment. The experimental group had 2 treatments. Treatment “A” consisted in 1 psychoeducation session. Treatment “B” was 1 visit (real or virtual) to the Thyssen-Bornemisza museum. Persons exercising as museum guides had been diagnosed with mental illness. They already were participants in the PCEA program of the CRPS Latina. The instrument to assess stigma was the AQ-27, validated in Spanish.

Results

We found significant reductions of stigma in all dimensions explored: Anger (A vs BC; P < 0.001), Threat (A vs BC; P < 0.001), Fear (A vs BC; P < 0.001), Coercion (A vs BC; P < 0.001) Segregation (A vs BC; P < 0.001) and Avoidance (A vs BC; P < 0.001).

Conclusions

The combination of treatments for intervention on stigma in samples of school students seems to be a very effective option to reduce stigma.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The stromal gene encoding the CD274 antigen as a genetic modifier controlling survival of mice with γ-radiation-induced T-cell lymphoblastic lymphomas

Using an inter-specific subcongenic strain, Nested Recombinant Haplotype 3 (NRH3), generated between two mouse strains showing extreme differences in γ-radiation-induced thymic lymphoma susceptibility (SEG/Pas and C57BL/6J), we have identified a critical region on chromosome 19 that regulates survival of mice suffering from T-cell lymphoblastic lymphomas. Mapped on this region, the gene encoding the Cd274 ligand is able to trigger an inhibitory effect that modulates T-cell receptor (TCR) signalling and affects thymocyte maturation. Interestingly, this gene shows differential expression between thymic stromal cells from both strains in early response to a single sublethal γ-ray dose, but is inhibited in T-cell lymphoblastic lymphomas. Furthermore, we have identified several polymorphisms in the complementary DNA sequence of this gene that affect the affinity for its Cd279 receptor and are able to induce a differential rate of thymocyte apoptosis. Taken together, our data are consistent with Cd274 acting as a genetic modifier that influences the survival of γ-radiation-induced T-cell lymphoma-bearing mice. The data similarly support the idea of a co-evolution of tumour cells and associated stromal cells to generate a favourable microenvironment for T-cell lymphoma growth.

[Morphologic changes in the proximal jejunum after partial hepatectomy in rats]

INTRODUCTION

Partial hepatectomy is being used with increasing frequency and wider surgical indications including living donor transplantation, particularly in children. Our aim was to study the morphologic changes that occur in the proximal jejunum as a result of the anatomic, functional, and metabolic unity of the liver and small intestine.

MATERIAL AND METHODS

Twenty-four Wistar rats were divided into 2 groups, a control group and an experimental group (30, 90, and 180 days). Changes in the proximal jejunum after 70% partial liver resection were studied by evaluating 4 parameters (total wall width, villous height, crypt depth, and villous thickness).

RESULTS

Jejunal total wall width increased significantly in the experimental group (p < 0.001). Villous height increased significantly in the experimental group as compared to the control group (p < 0.001). Villous thickness increased, and crypt depth decreased in the experimental group, but these changes were not statistically significant.

CONCLUSIONS

Partial hepatectomy (70%) originated trophic changes in the proximal jejunum that persisted in the short and long term, giving rise to parietal and villous hypertrophy.

Phylogeography and alpha taxonomy of the common dolphin (Delphinus sp.)

The resolution of taxonomic classifications for delphinid cetaceans has been problematic, especially for species in the genera Delphinus, Tursiops and Stenella. The frequent lack of correspondence between morphological and genetic differentiation in these species raises questions about the mechanisms responsible for their evolution. In this study we focus on the genus Delphinus, and use molecular markers to address questions about speciation and the evolution of population structure. Delphinus species have a worldwide distribution and show a high degree of morphological variation. Two distinct morphotypes, long-beaked and short-beaked, have been considered different species named D. capensis and D. delphis, respectively. However, genetic differentiation between these two forms has only been demonstrated in the Pacific. We analysed samples from eight different geographical regions, including two morphologically defined long-beaked form populations, and compared these with the eastern North Pacific populations. We found high differentiation among the populations described as long-beaked instead of the expected monophyly, suggesting that these populations may have evolved from independent events converging on the same morphotype. We observed low genetic differentiation among the short-beaked populations across a large geographical scale. We interpret these phylogeographical patterns in the context of life history and population structure in related species.

Lack of correlation between DNA copy number and mRNA expression levels ofc-myc in γ-radiation-induced mouse thymic lymphomas by using quantitative real-time PCR

BACKGROUND

It is well documented that over-expression of the c-myc proto-oncogene occurs in the vast majority of mouse thymic lymphomas induced by gamma-irradiation, evidencing the importance of this gene in T-cell lymphomagenesis. However, it remains unknown whether elevated levels of c-myc expression are driven by extra c-myc copy numbers.

MATERIALS AND METHODS

Here we use a quantitative test on the basis of real-time PCR to determine the cellular copy number of c-myc in a set of 14 g-radiation- induced thymic lymphomas obtained from (C57BL/6J x BALB/cJ) F1 hybrid mice with increased mRNA c-myc expression.

RESULTS

Since 5 out of 14 (35.7%) cases had no extra copy numbers of c-myc, gene amplification was obviously not the cause of c-myc over-expression in these tumours. In the remaining 9 tumours, c-myc over-expression was also accompanied with extra DNA copy numbers. Therefore, c-myc amplification might be a consequence of the genomic instability subsequent to the up-regulation of c-myc. However, linear regression analysis showed a lack of correlation between increasing DNA copy numbers and mRNA over expression of c-myc in these tumours (r = 0.029, p = 0.94).

CONCLUSION

De-regulation of c-myc does not necessarily imply amplification of this gene in these tumours. This report is, to our knowledge, the first one comparing c-myc amplification with expression in lymphomas of the T-cell lineage.

[Distensibility changes in the thoracic aorta after stent-graft implantation. Experimental study in healthy and atheromatous animals]

The implantation into the arterial lumen of a stent-graft has repercussions in the metabolism of the different layers of the arterial wall. The authors conducted an experimental study with the purpose of evaluating the mechanical repercussions of an endoprosthesis into the arterial wall in normal and atheromatous animals.

METHODS

The main group of animals was divided in two subgroups, the first with atheromatous induction and the second without treatment. Each subgroup was subdivided in two groups, a group with a simulated operation and the other with an endoprosthesis placed into the thoracic aorta. One half of the animals was evaluated at one month and the remaining at three months, with removal of the thoracic aorta. The animals were analyzed with electronics methods to assess the elasticity of the thoracic aorta.

RESULTS

The study found that ePTFE endoprosthetic grafts placed in atherosclerotic animals increased the intimal hyperplasia and wall alterations compared with the control group and the group with implantation in normal animals but this group showed less alterations of atherosclerosis than the group without endoprosthetic grafts.

DISCUSSION

Different factors may cause reactive changes in the arterial wall leading to atheromatosis in arteries with endoprosthesis implantation, but the lipid factor in induction of atheromatosis increases the possibility of alteration of the different layers of the arterial wall. The endoprosthesis implantation is an important factor for the development of the mechanical changes in the arterial wall.

New GABAA receptor alpha5 subunit gene polymorphism that may confound genotyping

We report the discovery of a new GABAA receptor alpha5 subunit gene polymorphism close to the polymorphism described by Glatt et al. (GT)5GCGTGC(GT)21. This new polymorphism is of great importance, because it means that non-denaturing acrylamide gels used to separate the different alleles of the polymorphism described by Glatt et al. cannot distinguish an allele with the sequence: (GT)4GCGTGC(GT)n from another allele with the sequence: (GT)4(GCGT)4GC(GT)(n-6). These gel fragments are separated by size, which would be the same in these two cases. An alternative would be to use an analysis method that can detect base changes, for instance, single strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE).

[Progress towards the use of DNA microarray technology for the study of wild Plasmodium strains]

Plasmodium falciparum is still a major cause of mortality in the world. Due to growing drug resistance in most endemic countries, the use of tools allowing large-scale analysis of P. falciparum biology is increasingly urgent. In addition to gene sequence data, post-genomic methods including microarray-based transcript profiling allow complete Plasmodium gene expression. However, application of this technology has been limited to study of samples presenting large quantities of total RNA (8 microg to 50 microg). Indeed at least two replicas (one technical and one biological) are necessary to ensure the statistical strength of results. This constraint excludes the use of biological materials hardly available and of wild strain samples. Many methods have been developed to facilitate the use of microarray technology with smaller quantities of total RNA. Currently the use of amplification techniques, various fluorochrome markers, and labelled cDNA and/or RNA probes avoiding all amplification steps, to enhance detection sensitivity has enabled reliable assays to be performed with less material. However these enhancement techniques appear to have a biasing effect on results and the use of powerful new markers is still limited for technical and practical reasons. At the present time radioactive labeling is the most reliable technique for assays using small quantities of total RNA. This approach is not only compatible with competitive hybridization but also enables all microarray screening criteria. Findings from our laboratory support the effectiveness of radioactive labeling for microarray-based determinations on P. falciparum.

Laparoscopic approach to incisional hernia

BACKGROUND

After more than 8 years of working in the field, we thought it would be interesting to evaluate our experience in the laparoscopic repair of abdominal wall hernias, focusing attention on the lessons learned with time.

METHODS

From January 1994 to November of 2000, a total of 270 patients with abdominal wall hernias were treated in our center using the laparoscopic approach. The data collected and analyzed were preoperative evaluation, operative findings, early and long-term complications, and recurrences.

RESULTS

The mean follow-up time was 44 months, mean surgical time was 85 min, and mean hospital stay was 1.5 days. The average number of abdominal wall defects was 4.8 per patient. There were 9 (3.3%) small bowel perforations. Conversion to open surgery was required in 1 case (0.3%). Minor early postoperative complications occurred in 38 patients (14.07%). Twenty patients (7.4%) developed persistent postoperative abdominal pain. There was 1 case (0.3%) of small bowel incarceration through the mesh border and another case (0.3%) of small bowel leakage due to ischemia and subsequent peritonitis. The relapse rate was 4.4% (12 cases).

CONCLUSION

The laparoscopic approach is a valuable option in the management of abdominal wall hernias, but it requires experience in laparoscopic surgery and there is a specific learning curve for the technique.

ERCP's role in the management of acute biliary-pancreatic pathology in the laparoscopic era

OBJECTIVES

Laparoscopic cholecystectomy (LC) combined with endoscopic retrograde cholangiopancreatography (ERCP) has been widely used in the management of the acute biliopancreatic pathology. Nevertheless, controversy remains about the appropriate timing for retrograde cholangiopancreatography.

METHODS

A retrospective study was undertaken on a consecutive series of 117 patients with acute biliary-pancreatic pathology, who underwent laparoscopic cholecystectomy between April 1995 and April 1999. Criteria for preoperative endoscopic retrograde cholangiopancreatography were defined, and the patients were divided into 3 groups based on the presence or absence of a preoperative retrograde cholangiopancreatography indication: (1) ERCP+LC group: patients with retrograde cholangiopancreatography indicated and performed (n = 30); (2) LC group: patients without retrograde cholangiopancreatography criteria treated only by LC (n = 47); (3) LC-ERCP group: patients with retrograde cholangiopancreatography criteria but not performed (n = 40).

RESULTS

The groups were similar in age, sex, ASA, and clinical diagnosis. No statistical differences occurred in operative times (73.8 min, 68 min, 67 min), major complications (3.3%, 4.25%, 12.5%), and mean postoperative stay (3.7 +/- 4; 4.7 +/- 2; 5.7 +/- 2). Postoperative retrograde cholangiopancreatography had to be used, respectively, in 0%, 10.6%, and 7.5%. The best predictive criteria for common bile duct pathology were choledocholithiasis on an ultrasound scan and the presence of cholangitis. The other criteria tested had a low predictive value.

CONCLUSIONS

Preoperative endoscopic retrograde cholangiopancreatography followed by early laparoscopic cholecystectomy can be performed safely in acute biliary-pancreatic pathology, avoiding 2-stage treatment of these patients and minimizing hospital stay and inconvenience to the patients. Nevertheless, this therapeutic/diagnostic tool must be used selectively.

Native and artificial reticuloplasmins co-accumulate in distinct domains of the endoplasmic reticulum and in post-endoplasmic reticulum compartments

We compared the subcellular distribution of native and artificial reticuloplasmins in endosperm, callus, and leaf tissues of transgenic rice (Oryza sativa) to determine the distribution of these proteins among endoplasmic reticulum (ER) and post-ER compartments. The native reticuloplasmin was calreticulin. The artificial reticuloplasmin was a recombinant single-chain antibody (scFv), expressed with an N-terminal signal peptide and the C-terminal KDEL sequence for retrieval to the ER (scFvT84.66-KDEL). We found that both molecules were distributed in the same manner. In endosperm, each accumulated in ER-derived prolamine protein bodies, but also in glutelin protein storage vacuoles, even though glutelins are known to pass through the Golgi apparatus en route to these organelles. This finding may suggest that similar mechanisms are involved in the sorting of reticuloplasmins and rice seed storage proteins. However, the presence of reticuloplasmins in protein storage vacuoles could also be due to simple dispersal into these compartments during protein storage vacuole biogenesis, before glutelin deposition. In callus and leaf mesophyll cells, both reticuloplasmins accumulated in ribosome-coated vesicles probably derived directly from the rough ER.

Two dimerization domains in the trans-activation response RNA-binding protein (TRBP) individually reverse the protein kinase R inhibition of HIV-1 long terminal repeat expression

Trans-activation response (TAR) RNA-binding protein (TRBP) is a cellular protein that binds to the human immunodeficiency virus-1 (HIV-1) TAR element RNA. It has two double-stranded RNA binding domains (dsRBDs), but only one is functional for TAR binding. TRBP interacts with the interferon-induced protein kinase R (PKR) and inhibits its activity. We used the yeast two-hybrid assay to map the interaction sites between the two proteins. We show that TRBP and PKR-N (178 first amino acids of PKR) interact with PKR wild type and inhibit the PKR-induced yeast growth defect in this assay. We characterized two independent PKR-binding sites in TRBP. These sites are located in each dsRBD in TRBP, indicating that PKR-TRBP interaction does not require the RNA binding activity present only in dsRBD2. TRBP and its fragments that interact with PKR reverse the PKR-induced suppression of HIV-1 long terminal repeat expression. In addition, TRBP activates the HIV-1 long terminal repeat expression to a larger extent than the addition of each domain. These data suggest that TRBP activates gene expression in PKR-dependent and PKR-independent manners.

Natural antisense transcripts are detected in different cell lines and tissues of cats infected with feline immunodeficiency virus

Feline immunodeficiency virus (FIV) is a lentivirus inducing an AIDS-like disease in cats, thus providing an interesting model for AIDS study. FIV and HIV-1 possess a similar genomic arrangement of structural and non-structural genes, whose expression is regulated by related genetic mechanisms. On the DNA strand complementary to the HIV-1 envelope messenger, an open reading frame (ORF) has been identified which encompasses the Rev Responsive Element (RRE), a cis-acting element critical to HIV gene expression. This ORF was highly conserved among HIV-1 isolates and had the potential to encode a hydrophobic protein. A corresponding antisense transcript was detected in cells infected with HIV-1, and appeared to encode an antisense protein. In the present study, we have identified a well-conserved antisense ORF, also coincident with the RRE region, in the genome of 21 FIV isolates. The predicted protein, 103 amino acids in length, is highly hydrophobic, as is the case for that of HIV-1. In addition, we have shown that a corresponding transcript, complementary to the transmembrane sequence of the FIV envelope gene, was produced in different cellular and viral contexts, that is, ex vivo and in vivo in FIV infected cell lines and tissues of infected cats, respectively. Expression of antisense transcripts might therefore be of general importance in the natural history of retroviruses.

Evidence of a possible epigenetic inactivation mechanism operating on a region of mouse chromosome 19 in γ-radiation-induced thymic lymphomas

Loss of heterozygosity (LOH) analysis, performed in 68 gamma-radiation-induced primary thymic lymphomas of F1 hybrid mice, provided evidence of significant LOH on chromosome 19 in a region defined by the D19Mit106 (22 cM) and D19Mit100 (27 cM) markers (Thymic Lymphoma Suppressor Region 8, TLSR8). Cd95 and Pten, two genes mapped at this region, were inactivated in a vast majority of these tumors (85.3% for Cd95 and 61.8% for Pten). Moreover, altered expression of Cd95 and Pten occurred concomitantly in 34 of 68 (50%) thymic lymphomas suggesting a coordinated mechanism of inactivation of these genes. Surprisingly, we also found that Jak2, a proto-oncogene located between Cd95 and Pten, was simultaneously inactivated in a significant fraction of the tumors analysed (24 of 34, 70.6%). Taken together these findings and the lack of mutations in the coding sequences of the mentioned genes clearly suggest a possible regional epigenetic inactivation mechanism on mouse chromosome 19 operating during the development of these tumors.

A study of selected Plasmodium yoelii messenger RNAs during hepatocyte infection

We investigated the expression of several mRNAs in exoerythrocytic and erythrocytic stages of Plasmodium yoelii in infected mice, focusing our attention on genes thought to be involved in signal transduction (like pypka and pymap-1, encoding homologues of cAMP-dependent and mitogen-activated protein kinases, respectively) and cell cycle progression (those encoding the cdc2-related kinases Pycrk-1, Pycrk-3 and Pymrk). Messengers coding for enzymes involved in general processes such as DNA replication and RNA transcription (both subunits of the ribonucleotide reductase (Pyrnr1, Pyrnr2) and RNA polymerase II) as well as a messenger coding for Pys21, a sexual stage-specific protein, were also investigated. Total RNA was prepared from livers of infected mice at different times post sporozoite inoculation. In contrast to the pys21 transcript, which was observed only in infected erythrocytes, all messenger species could be detected in the liver by RT-PCR, peaking at 43 h post infection, a time when parasite burden was maximum, and decreasing markedly thereafter to become hardly visible at 168 h. Some transcripts (pypka, pymap-1, pyrnr1 and pyrnr2) could be detected 12 h after infection, while others (pymrk and pyrnapolII) did not become detectable until 24 h. In addition, we characterised all these messengers by Northern blot of total RNAs extracted from infected erythrocytes. Taken together, these data suggest that a similar set of regulatory genes is expressed during both exoerythrocytic and erythrocytic schizogony.

Transabdominal surgical approach in the management of renal tumors involving the retrohepatic inferior vena cava

Multiple reports over the last decade have documented the clear superiority of surgery over other alternative treatments in the management of renal cell carcinoma with extension into the inferior vena cava (IVC). Controversy persists, however, regarding the management of tumor thrombus that extends retrohepatically, but not entering the right atrium. In this report, we retrospectively review our experience with the use of a feasible transabdominal technique without any form of bypass or anticoagulation for safe removal of renal tumor involving the retrohepatic IVC. From 1988 to 1998, 132 patients with renal cell carcinoma underwent radical nephrectomies at the urology service of our hospital. Five patients (3.8%) had retrohepatic venous extension through the renal vein into the IVC. Our transabdominal approach was accomplished by complete mobilization of the liver, control of the hepatocaval connection, total vascular exclusion of the IVC without heparin administration, removal of the tumor thrombus, and primary closure of the longitudinal vena cavotomy. From our results, we found the transabdominal approach with total vascular exclusion of the IVC to be satisfactory, with no early deaths, acceptable morbidity, and a remarkable limitation of blood loss and transfusion requirements.

Rice cell culture as an alternative production system for functional diagnostic and therapeutic antibodies

We investigated the suitability of transformed rice cell lines as a system for the production of therapeutic recombinant antibodies. Expression constructs encoding a single-chain Fv fragment (scFvT84.66, specific for CEA, the carcinoembryonic antigen present on many human tumours) were introduced into rice tissue by particle bombardment. We compared antibody production levels when antibodies were either secreted to the apoplast or retained in the endoplasmic reticulum (ER) using a KDEL retention signal. Production levels were up to 14 times higher when antibodies were retained in the ER. Additionally, we compared construct sencoding different leader peptides (plant codon optimised murine immunoglobulin heavy and light chain leader peptides from mAb24) and carrying alternative 5' untranslated regions (the petunia chalcone synthase gene 5' UTR and the tobacco mosaic virus omega sequence). We observed no significant differences in antibody production levels among cell lines transformed with these constructs. The highest level of antibody production we measured was 3.8 micrograms g-1 callus (fresh weight). Immunological analysis of transgenic rice callus confirmed the presence of functional scFvT84.66. We discuss the potential merits of cell culture for the production of recombinant antibodies and other valuable macromolecules.

Analysis of a binding difference between the two dsRNA-binding domains in TRBP reveals the modular function of a KR-helix motif

Double-stranded RNA-binding proteins constitute a large family with conserved domains called dsRBDs. One of these, TRBP, a protein that binds HIV-1 TAR RNA, has two dsRBDs (dsRBD1 and dsRBD2), as indicated by computer sequence homology. However, a 24-amino-acid deletion in dsRBD2 completely abolishes RNA binding, suggesting that only one domain is functional. To analyse further the similarities and differences between these domains, we expressed them independently and measured their RNA-binding affinities. We found that dsRBD2 has a dissociation constant of 5.9 x 10-8 M, whereas dsRBD1 binds RNA minimally. Binding analysis of 25-amino-acid peptides in TRBP and other related proteins showed that only one peptide in TRBP and one in Drosophila Staufen bind TAR and a GC-rich TAR-mimic RNA. Whereas a 25-mer peptide derived from dsRBD2 (TR5) bound TAR RNA, the equivalent peptide in dsRBD1 (TR6) did not. Molecular modelling indicates that this difference can mainly be ascribed to the replacement of Arg by His residues. Mutational analyses in homologous peptides also show the importance of residues K2 and L3. Analysis of 15-amino-acid peptides revealed that, in addition to TR13 (from TRBP dsRBD2), one peptide in S6 kinase has RNA-binding properties. On the basis of previous and the present results, we can define, in a broader context than that of TRBP, the main outlines of a modular KR-helix motif required for binding TAR. This structural motif exists independently from the dsRBD context and therefore has a modular function.

Cereal crops as viable production and storage systems for pharmaceutical scFv antibodies

This report describes the stable expression of a medically important antibody in the staple cereal crops rice and wheat. We successfully expressed a single-chain Fv antibody (ScFvT84.66) against carcinoembryonic antigen (CEA), a well characterized tumor-associated marker antigen. scFv constructs were engineered for recombinant antibody targeting to the plant cell apoplast and ER. Up to 30 microg/g of functional recombinant antibody was detected in the leaves and seeds of wheat and rice. We confirmed that transgenic dry seeds could be stored for at least five months at room temperature, without significant loss of the amount or activity of scFvT84.66. Our results represent the first transition from model plant expression systems, such as tobacco and Arabidopsis, to widely cultivated cereal crops, such as rice and wheat, for expression of an antibody molecule that has already shown efficacy in clinical applications. Thus, we have established that molecular pharming in cereals can be a viable production system for such high-value pharmaceutical macromolecules. Our findings provide a strong foundation for exploiting alternative uses of cereal crops both in industrialized and developing countries.

Laparoscopic treatment of ventral abdominal wall hernias: preliminary results in 100 patients

OBJECTIVE

The laparoscopic treatment of eventrations and ventral hernias has been little used, although these hernias are well suited to a laparoscopic approach. The objective of this study was to investigate the usefulness of a laparoscopic approach in the surgical treatment of ventral hernias.

METHODS

Between January 1994 and July 1998, a series of 100 patients suffering from major abdominal wall defects were operated on by means of laparoscopic techniques, with a mean postoperative follow-up of 30 months. The mean number of defects was 2.7 per patient, the wall defect was 93 cm2 on average. There were 10 minor hernias (<5 cm), 52 medium-size hernias (5-10 cm), and 38 large hernia (>10 cm). The origin of the wall defect was primary in 21 cases and postsurgical in 79. Three access ports were used, and the defects were covered with PTFE Dual Mesh measuring 19 x 15 cm in 54 cases, 10 x 15 cm in 36 cases, and 12 x 8 cm in 10 cases. An additional mesh had to be added in 21 cases. In the last 30 cases, PTFE Dual Mesh Plus with holes was employed.

RESULTS

Average surgery time was 62 minutes. One procedure was converted to open surgery, and only one patient required a second operation in the early postoperative period. Minor complications included 2 patients with abdominal wall edema, 10 seromas, and 3 subcutaneous hematomas. There were no trocar site infections. Two patients developed hernia relapse (2%) in the first month after surgery and were reoperated with a similar laparoscopic technique. Oral intake and mobilization began a few hours after surgery. The mean stay in hospital was 28 hours.

CONCLUSIONS

Laparoscopic technique makes it possible to avoid large incisions, the placement of drains, and produces a lower number of seromas, infections and relapses. Laparoscopic access considerably shortens the time spent in the hospital.

Real-time study of interactions between a composite DNA regulatory region (HIV-1 LTR NRE) and several transcription factors of nuclear extracts

Here we describe the first real-time study of nuclear protein interaction with a composite DNA regulatory region. We studied the interplay between the three target sites of the negative regulatory element (NRE) of HIV-1 LTR, comprising a noncanonical GATA site overlapping two negative regulatory regions, USF and NFIL-6, and their corresponding transcription factors in nuclear extracts. By bandshift analysis, no GATA binding activity could be detected between LTR NRE and different nuclear extracts, although evidenced by in vitro footprinting. Additionally, the LTR NRE and a USF oligonucleotide showed identical retarded complexes. BIAcore study of these interactions revealed the binding of huGATA-3, as well as USF, to the immobilized LTR NRE oligonucleotide. Competition analyses, performed with GATA, USF, and NFIL-6 oligonucleotides, clearly showed that this regulatory region could bind both huGATA-3 and USF factors. Finally, the presence of USF and huGATA-3 proteins in the complexes formed with LTR NRE was ascertained using specific anti-huGATA-3 and anti-USF2 polyclonal antibodies.

Transient expression of a tumor-specific single-chain fragment and a chimeric antibody in tobacco leaves

To evaluate the expression of different forms of a tumor-specific antibody in plants, we adapted a recently described Agrobacterium-mediated transient expression system. A recombinant single-chain Fv antibody (scFvT84.66) and a full-size mouse/human chimeric antibody (cT84.66) derived from the parental murine mAb T84. 66 specific for the human carcinoembryonic antigen were engineered into a plant expression vector. Chimeric T84.66 heavy and light chain genes were constructed by exchanging the mouse light and heavy chain constant domain sequences with their human counterparts and cloned into two independent plant expression vectors. In vivo assembly of full-size cT84.66 was achieved by simultaneous expression of the light and heavy chains after vacuum infiltration of tobacco leaves with two populations of recombinant Agrobacterium. Upscaling the transient system permitted purification of functional recombinant antibodies from tobacco leaf extracts within a week. His6-tagged scFvT84.66 was purified by immobilized metal affinity chromatography and cT84.66 by protein A affinity chromatography. Sufficient amounts of recombinant antibodies were recovered for detailed characterization by SDS/PAGE, Western blotting, and ELISA.

Venographic comparison of subcutaneous low-molecular weight heparin with oral anticoagulant therapy in the long-term treatment of deep venous thrombosis

PURPOSE

The primary objective of this study was to evaluate with venography the rate of thrombus regression after a fixed dose of low-molecular weight heparin (LMWH) per day for 3 months compared with oral anticoagulant therapy for deep venous thrombosis (DVT). Secondary endpoints were the comparisons of the efficacy and safety of both treatments.

METHODS

This study was designed as an open randomized clinical study in a university hospital setting. Of the 165 patients finally enrolled in the study, 85 were assigned LMWH therapy and 80 were assigned oral anticoagulant therapy. In the group randomized to oral anticoagulant therapy, the patients first underwent treatment in the hospital with standard unfractionated heparin and then coumarin for 3 months. Doses were adjusted with laboratory monitoring to maintain the international normalized ratio between 2.0 and 3.0. Patients in the LMWH group were administered subcutaneous injections of fixed doses of 40 mg enoxaparin (4000 anti-Xa units) every 12 hours for 7 days, and after discharge from the hospital, they were administered 40 mg enoxaparin once daily at fixed doses for 3 months without a laboratory control assay. A quantitative venographic score (Marder score) was used to assess the extent of the venous thrombosis, with 0 points indicating no DVT and 40 points indicating total occlusion of all deep veins. The rate of thrombus reduction was defined as the difference in quantitative venographic scores after termination of LMWH or coumarin therapy as compared with the scores obtained on the initial venographic results. The efficacy was defined as the ability to prevent symptomatic extension or recurrence of venous thromboembolism (documented with venograms or serial lung scans). The safety was defined as the occurrence of hemorrhages.

RESULTS

After 3 months of treatment, the mean Marder score was significantly decreased in both groups in comparison with the baseline score, although the effect of therapy was significantly better after LMWH therapy (49.4% reduction) than after coumarin therapy (24.5% reduction; P <.001). LMWH therapy and male gender were independently associated with an enhanced resolution of the thrombus. A lower frequency of symptomatic recurrent venous thromboembolism was also shown in patients who underwent treatment with LMWH therapy (9.5%) than with oral anticoagulant therapy (23.7%; P <.05), although this difference was entirely a result of recurrence of DVT. Bleeding complications were significantly fewer in the LMWH group than in the coumarin group (1. 1% vs 10%; P <.05). This difference was caused by minor hemorrhages. Coumarin therapy and cancer were independently associated with an enhanced risk of complications. Subcutaneous heparin therapy was well tolerated by all patients.

CONCLUSION

The patients who were allocated to undergo enoxaparin therapy had a significantly greater improvement in their quantitative venographic score, a significantly lower recurrence rate of symptomatic venous thromboembolism, and a significantly lower incidence of bleeding than patients who underwent treatment with coumarin. LMWH can be used on an outpatient basis as a safer and more effective alternative to classical oral anticoagulant therapy for the secondary prophylaxis of selected patients with DVT.

Laparoscopic treatment vs open surgery in the solution of major incisional and abdominal wall hernias with mesh

BACKGROUND

Despite being one of the most exact indications, laparoscopic treatment of eventrations and ventral hernias is barely known among the array of laparoscopic techniques.

METHODS

A total of 60 patients were assigned at random over a 3-year period to two homogeneous groups to be operated on for major ventral hernias with mesh. Half of them were operated upon laparoscopically and the rest with open surgery. Early and longer-term complications were analyzed, as were operative time and postoperative hospital stays.

RESULTS

The two groups were homogeneous in terms of demographic and clinical characteristics. The group that was operated on laparoscopically presented a lower rate of postoperative and longer-term complications; similarly, surgery time was significantly lower (p < 0.05). Hospitalization time was also significantly lower than in the group undergoing conventional open surgery (p < 0.05).

CONCLUSIONS

Laparoscopic treatment of postoperative eventration and primary ventral hernia reduces complications and relapse rates, eliminates reintervention through mesh infection, reduces operative time, and considerably shortens the hospital stay.

Superficial femoral artery as a substitute for common carotid artery affected by malignant cervical tumors

Tumoral disease of the arteries is uncommon. It is possible that, in tumoral reoperations affecting cervical structures, periarterial fibrosis due to radiotherapy and previous surgery and metastatic adherences to the arterial wall makes radical surgery difficult. We present a case where the surgical treatment of a regional relapse from laryngeal neoplasm needed the removal of the common carotid artery and its reconstruction with autologous patent superficial femoral artery. Surgical technique included a PTFE graft interposition in the leg.

Congenital malformations of the gallbladder and cystic duct diagnosed by laparoscopy: high surgical risk

Congenital anomalies of the gallbladder are rare and can be accompanied by other malformations of the biliary or vascular tree. Being difficult to diagnose during routine preoperative studies, these anomalies can provide surgeons with an unusual surprise during laparoscopic surgery. The presence of any congenital anomaly or the mere suspicion of its existence demands that we exercise surgical prudence, limit the use of electrocoagulation, and ensure that no structure be divided until a clear picture of the bile ducts and blood vessels is obtained. If necessary, perform intraoperative cholangiography to further define the biliary system. However, if the case remains unclear, or if laparoscopy does not provide enough information, open surgery should be considered before undesirable complications occur.