Evaluation of Immune Infiltrates in Ovarian Endometriosis and Endometriosis-Associated Ovarian Cancer: Relationship with Histological and Clinical Features

BACKGROUND

the association between ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC) is extensively documented, and misfunction of the immune system might be involved. The primary objective of this study was to identify and compare the spatial distribution of tumour-infiltrating lymphocytes (TILs) and tumour-associated macrophages (TAMs) in OE and EAOC. Secondary objectives included the analysis of the relationship between immunosuppressive populations and T-cell exhaustion markers in both groups.

METHODS

TILs (CD3, CD4, and CD8) and macrophages (CD163) were assessed by immunochemistry. Exhaustion markers (PD-1, TIM3, CD39, and FOXP3) and their relationship with tumour-associated macrophages (CD163) were assessed by immunofluorescence on paraffin-embedded samples from n = 43 OE and n = 54 EAOC patients.

RESULTS

we observed a predominantly intraepithelial CD3+ distribution in OE but both an intraepithelial and stromal pattern in EAOC (p < 0.001). TILs were more abundant in OE (p < 0.001), but higher TILs significantly correlated with a longer overall survival and disease-free survival in EAOC (p < 0.05). CD39 and FOXP3 significantly correlated with each other and CD163 (p < 0.05) at the epithelial level in moderate/intense CD4 EAOC, whereas in moderate/intense CD8+, PD-1+ and TIM3+ significantly correlated (p = 0.009). Finally, T-cell exhaustion markers FOXP3-CD39 were decreased and PD-1-TIM3 were significantly increased in EAOC (p < 0.05).

CONCLUSIONS

the dysregulation of TILs, TAMs, and T-cell exhaustion might play a role in the malignization of OE to EAOC.

A Need for Standardization of the Diagnosis and Treatment of Pelvic Inflammatory Disease: Pilot Study in an Outpatient Clinic in Quito, Ecuador

Background

Pelvic inflammatory disease (PID) diagnosis is often challenging as well as its treatment. This study sought to characterize the diagnostic and therapeutic trend among physicians at the outpatient level, in Quito, Ecuador, where currently no nationwide screening or specific clinical guideline has been implemented on PID or its main microbiological agents.

Methods

A retrospective analysis of medical records with pelvic inflammatory disease diagnosis in an outpatient clinic was performed. Electronic medical records from 2013 to 2018 with any pelvic inflammatory disease-related diagnoses were retrieved. Information with regard to age, sexually related risk factors, symptoms and physical exam findings, ancillary tests, method of diagnosis, and antibiotic regimens was extracted.

Results

A total of 186 records were included. The most frequent clinical manifestations were vaginal discharge (47%) and pelvic pain (39%). In the physical examination, leucorrhea was the most frequent finding (47%), followed by lower abdominal tenderness (35%) and cervical motion tenderness in 51 patients (27%). A clinical diagnosis was established in 60% of patients, while 37% had a transvaginal sonography-guided diagnosis. Antibiotic treatment was prescribed with standard regimens in 3% of cases, while other regimens were used in 93% of patients. Additionally, an average of 1.9 drugs were prescribed per patient, with a range from 1 to 5, all in different combinations and dosages.

Conclusions

No standardized methods of diagnosis or treatment were identifiable. These findings highlight the need for standardization of the diagnosis and treatment of PID attributed to chlamydial and gonococcal infections.

Influence of an external electric field on the rapid synthesis of MoO3 micro- and nanostructures by Joule heating of Mo wires

The growth mechanism of layered α-MoO₃ nano- and microplates on the surface of Mo wires during Joule heating has been investigated by application of an external electric field to the current carrying wire. The observed rapid growth of the structures, involving enhanced diffusion processes associated to the intense electric current, is further enhanced by the external field leading to a near instantaneous formation of MoO₃ plates. Thermally assisted electromigration in the Mo wire with the additional effect of the electric field appears as a very time effective method to grow MoO₃ layered low dimensional structures. Other molybdenum oxide nanostructures, such as nanospheres and nanocrystallites with different shapes, have been found to grow by deposition from the Mo wire on the electrodes used to apply the external electric field. The growth on the electrodes takes place by a thermally assisted electric-field-driven process.

Quantum nanoconstrictions fabricated by cryo-etching in encapsulated graphene

We report on a novel implementation of the cryo-etching method, which enabled us to fabricate low-roughness hBN-encapsulated graphene nanoconstrictions with unprecedented control of the structure edges; the typical edge roughness is on the order of a few nanometers. We characterized the system by atomic force microscopy and used the measured parameters of the edge geometry in numerical simulations of the system conductance, which agree quantitatively with our low temperature transport measurements. The quality of our devices is confirmed by the observation of well defined quantized 2e²/h conductance steps at zero magnetic field. To the best of our knowledge, such an observation reports the clearest conductance quantization in physically etched graphene nanoconstrictions. The fabrication of such high quality systems and the scalability of the cryo-etching method opens a novel promising possibility of producing more complex truly-ballistic devices based on graphene.

Study of mechanical resonances of Sb2O3 micro- and nanorods

Sb2O3 microrods with orthorhombic phase were grown by an evaporation-deposition method from a pure antimony source and substrate. The incorporation of Cr into the substrate has been found to enhance the growth of thinner rods with high crystalline quality, as is revealed by high resolution transmission electron microscopy (HRTEM). Electric field-induced mechanical resonances of Sb2O3 nanorods were studied by in situ measurements in a scanning electron microscope (SEM). Young's modulus of rods with different lengths and cross-sectional dimensions was calculated from the resonance frequency. The E values for the different rods were in the range of 16-48 GPa. For comparison, Young's moduli of several rods were also measured from the force-displacement curve recorded in an atomic force microscope (AFM). The slight difference between the E values obtained by the resonance and by the AFM techniques is within the accepted experimental error.

An adenine insertion in exon 6 of human GP6 generates a truncated protein associated with a bleeding disorder in four Chilean families

BACKGROUND

Glycoprotein VI (GPVI), 60-65 kDa, is a major collagen receptor on platelet membranes involved in adhesive and signaling responses. Mice lacking GPVI have impaired platelet response to collagen and defective primary adhesion and subsequent thrombus formation. Complete or partial deficiency of GPVI in humans is a rare condition presenting as a mild bleeding disorder. The defect in most of the reported patients is acquired and associated with other diseases. To date, only two patients have been characterized at the molecular level who carry different compound heterozygous mutations in the GP6 gene.

OBJECTIVE

To report four unrelated patients from non-consanguineous families who presented with mucocutaneous bleeding. They had absent platelet aggregation and (14) C-5-HT secretion with collagen, convulxin and collagen-related peptide.

RESULTS

Flow cytometry and immunofluorescence-confocal microscopy showed an absence of GPVI in non-permeabilized platelets. All the patients had an adenine insertion in exon 6 (c.711_712insA), changing the reading frame and generating a premature 'stop codon' in site 242 of the protein. The mutation predicts the synthesis of the truncated protein before the trans-membrane domain, corresponding to a band of ≈49 kDa observed in western blots and in permeabilized platelets by immunofluorescence. Platelet mRNA from all the patients was sequenced and contained the corresponding adenine insertion. Heterozygous relatives had no pathological bleeding, normal response to collagen and convulxin and intermediate membrane expression of GPVI.

CONCLUSIONS

The identification of four unrelated homozygous patients with an identical defect suggests that inherited GPVI deficiency is more frequent than previously suspected, at least in Chile.

Cathodoluminescence of rare earth implanted Ga2O3 and GeO2 nanostructures

Rare earth (RE) doped gallium oxide and germanium oxide micro- and nanostructures, mostly nanowires, have been obtained and their morphological and optical properties have been characterized. Undoped oxide micro- and nanostructures were grown by a thermal evaporation method and were subsequently doped with gadolinium or europium ions by ion implantation. No significant changes in the morphologies of the nanostructures were observed after ion implantation and thermal annealing. The luminescence emission properties have been studied with cathodoluminescence (CL) in a scanning electron microscope (SEM). Both β-Ga(2)O(3) and GeO(2) structures implanted with Eu show the characteristic red luminescence peak centered at around 610 nm, due to the (5)D(0)-(7)F(2) Eu(3+) intraionic transition. Sharpening of the luminescence peaks after thermal annealing is observed in Eu implanted β-Ga(2)O(3), which is assigned to the lattice recovery. Gd(3+) as-implanted samples do not show rare earth related luminescence. After annealing, optical activation of Gd(3+) is obtained in both matrices and a sharp ultraviolet peak centered at around 315 nm, associated with the Gd(3+) (6)P(7/2)-(8)S(7/2) intraionic transition, is observed. The influence of the Gd ion implantation and the annealing temperature on the gallium oxide broad intrinsic defect band has been analyzed.

Structural and magnetic properties of pure and nickel doped SnO2 nanoparticles

Ni-doped SnO2 nanoparticles prepared by a polymer precursor method have been characterized structurally and magnetically. Ni doping (up to 10 mol%) does not significantly affect the crystalline structure of SnO2, but stabilizes smaller particles as the Ni content is increased. A notable solid solution regime up to ∼ 3 mol% of Ni, and a Ni surface enrichment for the higher Ni contents are found. The room temperature ferromagnetism with saturation magnetization (MS) ∼ 1.2 × 10 (- 3) emu g (- 1) and coercive field (HC) ∼ 40 Oe is determined for the undoped sample, which is associated with the exchange coupling of the spins of electrons trapped in oxygen vacancies, mainly located on the surface of the particles. This ferromagnetism is enhanced as the Ni content increases up to ∼ 3 mol%, where the Ni ions are distributed in a solid solution. Above this Ni content, the ferromagnetism rapidly decays and a paramagnetic behavior is observed. This finding is assigned to the increasing segregation of Ni ions (likely formed by interstitials Ni ions and nearby substitutional sites) on the particle surface, which modifies the magnetic behavior by reducing the available oxygen vacancies and/or the free electrons and favoring paramagnetic behavior.

Bristled shark skin: a microgeometry for boundary layer control?

There exists evidence that some fast-swimming shark species may have the ability to bristle their scales during fast swimming. Experimental work using a water tunnel facility has been performed to investigate the flow field over and within a bristled shark skin model submerged within a boundary layer to deduce the possible boundary layer control mechanisms being used by these fast-swimming sharks. Fluorescent dye flow visualization provides evidence of the formation of embedded cavity vortices within the scales. Digital particle image velocimetry (DPIV) data, used to evaluate the cavity vortex formation and boundary layer characteristics close to the surface, indicate increased momentum in the slip layer forming above the scales. This increase in flow velocity close to the shark's skin is indicative of boundary layer control mechanisms leading to separation control and possibly transition delay for the bristled shark skin microgeometry.

Sn doped GeO(2) nanowires with waveguiding behavior

Sn doped GeO(2) nanowires and microwires have been grown by an evaporation-deposition method, using a mixture of Ge and SnO(2) powders as precursors. Comparison with undoped GeO(2) nanowires grown by the same method shows that the presence of Sn prevents the formation of sharp bends, which makes the wires more suitable for waveguiding applications. Incorporation of about 0.5 at.% of Sn into the wires influences their morphology and gives rise to wires showing two different cross-sectional dimensions along the growth axis. Sn does not influence the luminescence spectra in the visible range but causes the appearance of emission bands in the near-infrared range. The waveguiding behavior of the Sn doped wires for green and red laser light has been demonstrated.

Sensory and analytical study of rose sparkling wines manufactured by second fermentation in the bottle

The sensory and analytical characteristics of five rose sparkling wines manufactured by the traditional method have been determined. Moreover, the changes that take place in the nitrogen and volatile fraction of the wines during the second fermentation and the aging with the yeasts have been studied. Each of these wines was made from a single industrial rose base wine of the Garnacha Tinta variety, with five selected yeasts strains. The base wine had a low content in free amino acids, 16 mg/L, and the yeast consumed more peptides than free amino acids during second fermentation. From the application of the two-way analysis of variance, yeast strain, and aging time factors to the data of volatile compounds, it has been found that most of the differences between these sparkling wines are due to the aging time. It has been verified that these rose sparkling wines have foam of good quality and that the grape variety Garnacha Tinta is suitable for the production of rose sparkling wines.

[Evaluation of lercanidipine in the general practice setting]

OBJECTIVE

To determine the efficacy and tolerability of a long-acting dihydropyridine in the clinical settings of general practice.

MATERIAL AND METHODS

110 essential hypertensives were included (age 62.3 +/- 10.8 years, 51 men and 53 women, 38/ obese -IMC >30 kg/m2, ten diabetics). 104 patients ended the followup. Patients were treated with lercanidipine 10 mg once daily in the morning. Follow-up lasted 6 months. When blood pressure was not controlled (BP < 140/90 mmHg) in any visit, a second drug was added, excluding calcium channel blockers. Antiadrenergic drugs were recommended. If patients were not controlled ittwo consecutive visits they were excluded from follow-up.

RESULTS

Significant reductions in both systolic (baseline 157.4 +/- 11.7 vs 131.1 +/- 6.8 mmHg, p < 0,001) and diastolic BP (baseline 94.7 +/- 5.8 vs 80.0 +/- 5.5 mmHg, p < 0,001) were attained at six months. Mean SBP decrease was 26.7 mmHg and mean DBP reduction was 15.6 mmHg. At the study end, 84.3/ of the patients achieved a BP < 140/90 mmHg. Thirty patients needed a second drug to become controlled (26 at the study end). The overall incidence of adverse effects was 4,4/ (n=6) and just three patients withdrew the treatment due to untoward effects. Plasmatic cholesterol lowered from 225.3 +/- 41.0 to 216.7 +/- 25.3 mg/dl (p = 0,03) and urate decreased from 5.6 +/- 1.6 to 5.1 +/- 1.4 mgldl, p = 0,03).

CONCLUSIONS

Lercanidipine is a calcium channel blockers of high efficacy and low incidence of adverse effects in the clinical settings of general practice. It seems to have a positive metabolic effects on plasmatic levels of cholesterol and urate.

Evaluation of molecular techniques for the genetic characterization of Saccharomyces cerevisiae strains

The applicability of different PCR-based techniques, random amplified polymorphic DNA, cleaved amplified polymorphic sequence and SSRs (simple sequence repeats) to genetically identify, typify and discriminate among Saccharomyces cerevisiae strains, was investigated. The analysis and comparison of the genetic profiles obtained for each of the techniques allowed determination of the degree of polymorphism, genetic diversity and relationships among the strains. Consequently, the discriminatory power and usefulness of the molecular techniques assayed was established. SSR analysis was the most effective method due to its high level of polymorphism, the ease of interpretation of the genetic profiles obtained, and the speed of use.

Detection, distribution and selection of microsatellites (SSRs) in the genome of the yeast Saccharomyces cerevisiae as molecular markers

AIMS

The aim of this work was the selection of six polymorphic microsatellite loci for their use as molecular markers in the identification, typification and genetic differentiation of S. cerevisiae strains.

METHODS AND RESULTS

The selection was undertaken following a search of the genomic DNA database of Saccharomyces cerevisiae for simple tandem repeat sequences (microsatellites) of di- and trinucleotides. The genetic variability generated by these markers was evaluated in 51 isolates. The discriminatory power produced by combining the information obtained by the six microsatellites was very high. A total of 57 alleles, which generated 44 genotypes, were found.

CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY

The multiple analysis of microsatellites proved to be a powerful and agile tool for analysing the genome of S. cerevisiae populations.

Recruitment of the transcriptional machinery through GAL11P: structure and interactions of the GAL4 dimerization domain

The GAL4 dimerization domain (GAL4-dd) is a powerful transcriptional activator when tethered to DNA in a cell bearing a mutant of the GAL11 protein, named GAL11P. GAL11P (like GAL11) is a component of the RNA-polymerase II holoenzyme. Nuclear magnetic resonance (NMR) studies of GAL4-dd revealed an elongated dimer structure with C(2) symmetry containing three helices that mediate dimerization via coiled-coil contacts. The two loops between the three coiled coils form mobile bulges causing a variation of twist angles between the helix pairs. Chemical shift perturbation analysis mapped the GAL11P-binding site to the C-terminal helix alpha3 and the loop between alpha1 and alpha2. One GAL11P monomer binds to one GAL4-dd dimer rendering the dimer asymmetric and implying an extreme negative cooperativity mechanism. Alanine-scanning mutagenesis of GAL4-dd showed that the NMR-derived GAL11P-binding face is crucial for the novel transcriptional activating function of the GAL4-dd on GAL11P interaction. The binding of GAL4 to GAL11P, although an artificial interaction, represents a unique structural motif for an activating region capable of binding to a single target to effect gene expression.

A nuclear casein kinase 2 activity is involved in early events of transcriptional activation induced by salicylic acid in tobacco

Salicylic acid (SA) activates immediate early transcription of genes controlled by a family of DNA promoter elements named as-1-like elements. These elements are functional in the promoter of glutathione S-transferase genes. We have previously shown that SA increases the binding of tobacco (Nicotiana tabacum cv Xanthi nc) nuclear factors to the as-1 sequence in a process mediated by protein phosphorylation. In this study we give evidence for the participation of a nuclear protein kinase CK2 (casein kinase 2) in the pathway activated by SA in tobacco. The first line of evidence comes from the evaluation of the CK2 activity in nuclear extracts prepared from tobacco plants treated with SA or water as a control. Results from these experiments indicate that SA increases the nuclear CK2 activity. The second line of evidence derives from the evaluation of the in vivo effect of 5,6-dichloro-1-(beta-D-ribofuranosyl) benzimidazole (DRB), a cell-permeable CK2 inhibitor, on the responsiveness of the as-1 sequence to SA. Results from these experiments indicate that DRB impairs the activating effect of SA on the transcription of both, the GUS reporter gene controlled by a tetramer of the as-1 element, and the endogenous gnt35 gene encoding a glutathione S-transferase, in transgenic tobacco plants. DRB also impaired the increasing effect of SA on the binding of nuclear factors to the as-1 element. Furthermore, transcription of the as-1/GUS reporter gene activated by the synthetic auxin 2,4-dichlorophenoxyacetic acid and by methyl jasmonate was also inhibited by DRB. To our knowledge, this is the first report in which activation of a CK2 enzyme by a plant hormone is reported.

Glycoprotein Ib/IX complex is the target in rifampicin-induced immune thrombocytopenia

Thrombocytopenia is a major adverse effect of several drug treatments. Rifampicin has been recognized as a cause of immune thrombocytopenia during intermittent high-dose therapy. We characterized the antibody of a patient who presented with purpura and thrombocytopenia during treatment of tuberculosis with rifampicin. Drug-dependent binding of the antibody to platelets was demonstrated by flow cytometry. In a glycoprotein-specific immunoassay, the binding epitope of the IgG antibody was found in the glycoprotein Ib/IX complex, using four different monoclonal antibodies (mAbs) against various epitopes on the GPIb/IX complex, as well as mAbs against GPIIb/IIIa, GPIa/IIa and GPIV. By immunoprecipitation of biotin-labelled platelets, reactivity of the antibody with GPIb/IX was found only in the presence of the drug. These findings clearly demonstrate that rifampicin induces the formation of drug-dependent antibodies capable of causing thrombocytopenia. The binding site of the rifampicin-dependent antibody, located in the GPIb/IX complex, seems to be a favoured target for antibodies induced by different drugs.

[Cushing with transition from pituitary to adrenal origin. Study with SPECT scintigraphy of the adrenal cortex with norcholesterol-I 131 in a case]

The case of a 49 yr old alcoholic women with clinical and laboratory findings that suggested a Cushing syndrome is presented. The functional tests showed cortisol suppression greater than 50% of the basal value with 8 mg of dexamethasone and no response in the combined dexamethasone/desmopressin test. Pituitary Nuclear Magnetic Resonance (NMR) was negative, Abdominal Computed Axial Tomography suggested hyperplastic adrenal glands; adrenal nodules were not found in the NMR. Pituitary or hipothalamic Cushing with secondary autonomous micronodular adrenal hyperplasia was suspected. Norcholesterol-I131 SPECT scintigraphy under dexamethasone suppression demonstrated a functional adrenal hyperplasia which was hystologically confirmed.

[Transplacental alloimmunization against specific platelet antigens: prevalence and features in a Chilean population]

BACKGROUND

Neonatal alloimmune thrombocytopenia (NAIT) is a result of fetomaternal incompatibility. Platelet destruction is caused by a maternal antibody directed against a fetal platelet antigen inherited from the father and lacking on the mother's platelets. The incidence and features of transplacental alloimmunization depend on the frequency of expression of platelet specific antigens; which are highly variable among different populations.

AIM

To determine the prevalence and characteristics of transplacental alloimmunization in a large group of pregnant women in Chile.

MATERIAL AND METHODS

We studied 3,041 samples obtained during the third trimester of gestation. In all samples, anti platelet antibodies were screened by ELISA with platelet membranes fixed to a microtiter plate. Positive samples were further studied for antigenic specificity with the monoclonal antibody specific immobilization of platelet antigens (MAIPA) test.

RESULTS

Anti platelet antibodies were found in 261 samples (8.5%). The MAIPA test identified 6 samples with antibodies directed against major platelet membrane glycoproteins, 2 anti GPIb, 2 anti GPIIb/IIIa and 2 anti GPIa/IIa. In four cases, anti HLA antibodies coexisted. Two cases corresponded to well defined platelet antigen systems: one anti HPA-1a and one anti HPA-5b. No clinical evidence of thrombocytopenia of the newborn was detected in all these cases with anti GP antibodies.

CONCLUSIONS

A prevalence of platelet specific antibodies of 0.2% with only one anti HPA-1a was detected. These findings are in contrast with those of other populations but in accordance with the low frequency of the HPA-1 b/b phenotype in the Chilean population. The very low incidence of platelet specific antibodies and the lack of association with clinical thrombocytopenia in the newborn, do not support the recommendation of routine antenatal screening to all women in Chile.

Use of store and forward technology for vascular nursing teleconsultation service

Accurate assessment is critical in planning appropriate therapeutic management of a patient with a vascular wound. However, several factors may inhibit wound assessment by trained professionals or subspecialists. Multiple co-morbidities and lack of transportation and finances contribute to problems with access to specialty clinics for both rural and urban patients with vascular disease. To assess the application of telemedicine in meeting the needs of rural patients with vascular disease, the vascular nurse clinician of a regional medical network was incorporated into a telemedicine research project that used a still-image transmission system known as the Picasso telephone, which allows a diagnostic quality image to be transmitted over a regular telephone line. Telephone consultation between sender and receiver occurs simultaneously at the time of image transmission. Because images can be collected and stored for future reference, this technology is commonly called "store and forward" technology. The application of advanced technology in a rural health care environment has the potential to reduce costs for both patient and managed care insurance plans, allow for expert consultation from distant centers, and promote collegiality and learning among professionals.

[Platelet alloimmunization in patients with oncologic blood disorders treated with multiple transfusions: prospective study in adults and children]

BACKGROUND

Refractoriness continues to be a major complication of platelet transfusion therapy in patients with multiple transfusions. Despite most cases are secondary to non-immune causes, the most serious is that associated to alloimmunization. The incidence and consequences of HLA and non-HLA (platelet specific) antibodies are unknown in our country.

AIM

To prospectively determine the frequency and characteristics of post transfusion alloimmunization and the incidence of platelet specific antibodies.

PATIENTS AND METHODS

Forty one adults and 24 children with a recently diagnosed malignancy and undergoing chemotherapy that required multiple transfusions were studied. Screening for antiplatelet antibodies (platelet membrane ELISA) was performed before the first transfusion, every four weeks or whenever the 1 hour corrected count increment for platelet transfusions was lower than 5000. Platelet specific antibodies were identified with a monoclonal antibody-specific immobilization of platelet antigens (MAIPA), with anti-GPIb, GPIIb/IIIa, GPIa/Iia and anti-HLA class I.

RESULTS

Adult patients received an average of 10.2 +/- 5.5 units of red blood cells and 58.6 +/- 35.4 units of platelets. Children received 4.8 +/- 3.7 units of red blood cells and 9.6 +/- 6.7 units of platelets. HLA antibodies appeared in 7 of 41 adult patients (17%), platelet specific alloantibodies were found in two patients (one anti GP Ia/IIa and one anti GP Ib). Platelet refractoriness appeared in three alloimmunized patients. No child had detectable serum antibodies during follow up.

CONCLUSIONS

Platelet transfusion refractoriness of immune origin occurs infrequently in our population and the presence of platelet antibodies does not mean that it will appear. The use of leukocyte depleted blood components to prevent refractoriness cannot be justified at this time.

[Activated C protein resistance: laboratory study and prevalence of the defect in the Chilean population]

Activated protein C resistance (APCR) or Factor V Leiden has been recently described as the most prevalent hemostatic abnormality associated with venous thrombosis. In patients with familial thrombophilia, the prevalence of APCR is 19-60% and around 20% in sporadic venous thrombosis. APCR is usually measured by the degree of prolongation of Activated Partial Thromboplastin Time (APTT) on patient's plasma, induced by addition of APC in comparison to normal plasma. At the molecular level the defect is caused by a single-point mutation in the gene for factor V (FV) (G1.691-->A), that predicts the replacement of Arg506 by Glutamine. This mutation makes activated factor V resistant to inactivation by APC. Since the prevalence of the defect is highly variable among different populations, the objective of this work was to study its frequency in our population and in patients with thrombophilia. We defined the normal range for APTT ratio (APTT + APC/APTT - APC) in a group of 73 healthy volunteers in whom the presence of FV Q506 mutation was searched using Mull enzyme digestion of PCR amplified genomic fragment containing the nucleotide 1.691. The lower limit of APTT ratio established in this group was 2.13. APCR was found in 6 out of 159 control subjects (3.8%) and in 14/50 (28%) of patients with thrombosis. In 13 cases as a single defect and in one associated to type I protein C deficiency. All the APCR patients and control subjects were heterozygotes by gene analysis. The results demonstrate that in our population APCR is also the most common defect associated with thrombosis, in accordance with a high prevalence in the population. The ability to screen for this defect will permit the identification of carriers that would benefit of preventive therapy at risk situations.

Platelet autoantibodies in patients with chronic liver disease

The thrombocytopenia in chronic liver disease (CLD) has been attributed mainly to hypersplenism, although other factors such as reduced mean life span with increased platelet turnover have also been demonstrated. Immunological abnormalities have been described in the pathogenesis and progression of CLD. In this sense, many studies have reported elevated levels of platelet associated IgG (PAIgG) in patients with CLD, and it has been suggested that PAIgG could represent true antiplatelet antibody. In this study we used a glycoprotein (GP)-specific immunoassay (MACE) to determine whether PAIgG or circulating antiplatelet antibodies, reacted against the GPIIb/IIIa or GPIb/IX complexes, in patients with CLD. Thirty-six patients with CLD of diverse etiology were studied (20 female, mean age 53 years, range 38-75 years). 23 out of 36 patients (64%) had anti-GP antibodies in MACE. Particularly, 12 had anti-GPIb, 4 anti-GPIIb/IIIa, and 7 had both types of autoantibodies. The existence of these anti-GP antibodies was not related with the blood platelet count or etiology of CLD. These data show that in patients with CLD of diverse origin, there is a high prevalence of autoantibodies reacting specifically with platelet membrane GP, which constitutes the first evidence of the specific nature of platelet-bound IgG in CLD. These findings suggest that in patients with CLD, an immune mechanism may participate in inducing or aggravating the thrombocytopenia.

Solution structure of the potassium channel inhibitor agitoxin 2: caliper for probing channel geometry

The structure of the potassium channel blocker agitoxin 2 was solved by solution NMR methods. The structure consists of a triple-stranded antiparallel beta-sheet and a single helix covering one face of the beta-sheet. The cysteine side chains connecting the beta-sheet and the helix form the core of the molecule. One edge of the beta-sheet and the adjacent face of the helix form the interface with the Shaker K+ channel. The fold of agitoxin is homologous to the previously determined folds of scorpion venom toxins. However, agitoxin 2 differs significantly from the other channel blockers in the specificity of its interactions. This study was thus focused on a precise characterization of the surface residues at the face of the protein interacting with the Shaker K+ channel. The rigid toxin molecule can be used to estimate dimensions of the potassium channel. Surface-exposed residues, Arg24, Lys27, and Arg31 of the beta-sheet, have been identified from mutagenesis studies as functionally important for blocking the Shaker K+ channel. The sequential and spatial locations of Arg24 and Arg31 are not conserved among the homologous toxins. Knowledge on the details of the channel-binding sites of agitoxin 2 formed a basis for site-directed mutagenesis studies of the toxin and the K+ channel sequences. Observed interactions between mutated toxin and channel are being used to elucidate the channel structure and mechanisms of channel-toxin interactions.

Revealing the architecture of a K+ channel pore through mutant cycles with a peptide inhibitor

Thermodynamic mutant cycles provide a formalism for studying energetic coupling between amino acids on the interaction surface in a protein-protein complex. This approach was applied to the Shaker potassium channel and to a high-affinity peptide inhibitor (scorpion toxin) that binds to its pore entryway. The assignment of pairwise interactions defined the spatial arrangement of channel amino acids with respect to the known inhibitor structure. A strong constraint was placed on the Shaker channel pore-forming region by requiring its amino-terminal border to be 12 to 15 angstroms from the central axis. This method is directly applicable to sodium, calcium, and other ion channels where inhibitor or modulatory proteins bind with high affinity.

Purification and characterization of three inhibitors of voltage-dependent K+ channels from Leiurus quinquestriatus var. hebraeus venom

Three new toxins from the venom of the scorpion Leiurus quinquestriatus var. hebraeus have been identified on the basis of their ability to block the Shaker K+ channel. These toxins have been purified using HPLC techniques and characterized as 38 amino acid peptides by mass spectroscopy, amino acid analysis, and sequence determination. Their chemical identity was confirmed by producing fully functional synthetic toxins using recombinant methods. These peptides are potent inhibitors of the Shaker K+ channel (Kd < 1 nM) as well as the mammalian homologues of Shaker. They are related to other previously described K+ channel toxins, but form a new subclass within the larger family of K+ channel inhibitors derived from scorpion venom. We have named these toxins agitoxin 1, 2, and 3, respectively.

Non-neuronal endogenous GABA efflux from the rat oviduct

The subcellular distribution of Gamma-aminobutyric acid (GABA) was studied in the rat oviduct. The highest content of GABA was found in the soluble fraction. The effect of chemical stimulation of the endogenous GABA efflux from the rat oviduct was examined. High K+ concentrations could not induce elevation of the GABA efflux. Instead, a continuous spontaneous GABA efflux without change for long periods of time was observed. The total GABA content and GABA concentration were determined in the rat oviduct on days 1, 5, 10, 15, 30, 35 and 40 of the postnatal period and also during the estrous cycle. During postnatal development the GABA levels increase gradually with time reaching at prepuberal age a concentration similar to that found in diestrous rats. In the estrous cycle both GABA content and GABA concentration reached the highest value in the proestrous and the lowest value in the estrous phase. These findings support the hypothesis that GABA efflux may be modulated by the changes in oviductal fluid volume during the estrous cycle.

[ Taxonomic study of the yeast flora of musts and wines from "Madrid wines"]

The natural yeast flora of musts and wines elaborated in wineries of the three Madrid viticultural areas, has been taxonomically analyzed. Two hundred and seventy yeast strains belonging to eighteen species, have been isolated, and Sacch. cerevisiae strains are the most frequent. The chemical characterization of samples with enological parameters defines the yeast fermentative ecosystem.

A cyclic AMP-activated K+ channel in Drosophila larval muscle is persistently activated in dunce

Single-channel recording from longitudinal ventrolateral Drosophila larval muscle reveals the presence of a potassium-selective channel that is directly and reversibly activated by cAMP in a dose-dependent fashion. Activation is specific and it cannot be mimicked by a series of agents that include AMP, cGMP, ATP, inositol trisphosphate, and Ca2+. Channel current records obtained from larval muscle in different dunce mutants possessing abnormally high levels of cAMP show that, in the mutants, the channel displays an increased probability of opening.