Validation of mutated CEBPA bZIP as a distinct prognosis entity in acute myeloid leukemia: a study by the Spanish PETHEMA registry

Not available.

Comparison of the 2022 and 2017 European LeukemiaNet risk classifications in a real-life cohort of the PETHEMA group

Next-Generation Sequencing is needed for the accurate genetic risk stratification of acute myeloid leukemia according to European LeukemiaNet (ELN) guidelines. We validated and compared the 2022 ELN risk classification in a real-life cohort of 546 intensively and 379 non-intensively treated patients. Among fit patients, those aged ≥65 years old showed worse OS than younger regardless risk classification. Compared with the 2017 classification, 14.5% of fit patients changed the risk with the 2022 classification, increasing the high-risk group from 44.3% to 51.8%. 3.7% and 0.9% FLT3-ITD mutated patients were removed from the favorable and adverse 2017 categories respectively to 2022 intermediate risk group. We suggest that midostaurin therapy could be a predictor for 3 years OS (85.2% with vs. 54.8% without midostaurin, P = 0.04). Forty-seven (8.6%) patients from the 2017 intermediate group were assigned to the 2022 adverse-risk group as they harbored myelodysplasia (MDS)-related mutations. Patients with one MDS-related mutation did not reach median OS, while patients with ≥2 mutations had 13.6 months median OS (P = 0.002). Patients with TP53 ± complex karyotype or inv(3) had a dismal prognosis (7.1 months median OS). We validate the prognostic utility of the 2022 ELN classification in a real-life setting providing supportive evidences to improve risk stratification guidelines.

Molecular Landscape and Validation of New Genomic Classification in 2668 Adult AML Patients: Real Life Data from the PETHEMA Registry

Next-Generation Sequencing (NGS) implementation to perform accurate diagnosis in acute myeloid leukemia (AML) represents a major challenge for molecular laboratories in terms of specialization, standardization, costs and logistical support. In this context, the PETHEMA cooperative group has established the first nationwide diagnostic network of seven reference laboratories to provide standardized NGS studies for AML patients. Cross-validation (CV) rounds are regularly performed to ensure the quality of NGS studies and to keep updated clinically relevant genes recommended for NGS study. The molecular characterization of 2856 samples (1631 derived from the NGS-AML project; NCT03311815) with standardized NGS of consensus genes (ABL1, ASXL1, BRAF, CALR, CBL, CEBPA, CSF3R, DNMT3A, ETV6, EZH2, FLT3, GATA2, HRAS, IDH1, IDH2, JAK2, KIT, KRAS, MPL, NPM1, NRAS, PTPN11, RUNX1, SETBP1, SF3B1, SRSF2, TET2, TP53, U2AF1 and WT1) showed 97% of patients having at least one mutation. The mutational profile was highly variable according to moment of disease, age and sex, and several co-occurring and exclusion relations were detected. Molecular testing based on NGS allowed accurate diagnosis and reliable prognosis stratification of 954 AML patients according to new genomic classification proposed by Tazi et al. Novel molecular subgroups, such as mutated WT1 and mutations in at least two myelodysplasia-related genes, have been associated with an adverse prognosis in our cohort. In this way, the PETHEMA cooperative group efficiently provides an extensive molecular characterization for AML diagnosis and risk stratification, ensuring technical quality and equity in access to NGS studies.

Next-Generation DNA Sequencing-Based Gene Panel for Diagnosis and Genetic Risk Stratification in Onco-Hematology

A suitable diagnostic classification of myeloid neoplasms and acute leukemias requires testing for a large number of molecular biomarkers. Next-generation sequencing is a technology able to integrate identification of the vast majority of them in a single test. This manuscript includes the design, analytical validation and clinical feasibility evaluation of a molecular diagnostic kit for onco-hematological diseases. It is based on sequencing of the coding regions of 76 genes (seeking single-nucleotide variants, small insertions or deletions and CNVs), as well as the search for fusions in 27 target genes. The kit has also been designed to detect large CNVs throughout the genome by including specific probes and employing a custom bioinformatics approach. The analytical and clinical feasibility validation of the Haematology OncoKitDx panel has been carried out from the sequencing of 170 patient samples from 6 hospitals (in addition to the use of commercial reference samples). The analytical validation showed sensitivity and specificity close to 100% for all the parameters evaluated, with a detection limit of 2% for SNVs and SVs, and 20% for CNVs. Clinically relevant mutations were detected in 94% of all patients. An analysis of the correlation between the genetic risk classification of AML (according to ELN 2017) established by the hospitals and that obtained by the Haematology OncoKitDx panel showed an almost perfect correlation (K = 0.94). Among the AML samples with a molecular diagnosis, established by the centers according to the WHO, the Haematology OncoKitDx analysis showed the same result in 97% of them. The panel was able to adequately differentiate between MPN subtypes and also detected alterations that modified the diagnosis (FIP1L1-PDGFRA). Likewise, the cytogenetic risk derived from the CNV plot generated by the NGS panel correlated substantially with the results of the conventional karyotype (K = 0.71) among MDS samples. In addition, the panel detected the main biomarkers of prognostic value among patients with ALL. This validated solution enables a reliable analysis of a large number of molecular biomarkers from a DNA sample in a single assay.

Networking for advanced molecular diagnosis in acute myeloid leukemia patients is possible: the PETHEMA NGS-AML project

Next-generation sequencing (NGS) has recently been introduced to efficiently and simultaneously detect genetic variations in acute myeloid leukemia (AML). However, its implementation in the clinical routine raises new challenges focused on the diversity of assays and variant reporting criteria. In order to overcome this challenge, the PETHEMA group established a nationwide network of reference laboratories aimed to deliver molecular results in the clinics. We report the technical cross-validation results for NGS panel genes during the standardization process and the clinical validation in 823 samples of 751 patients with newly diagnosed or refractory/relapse AML. Two cross-validation rounds were performed in seven nationwide reference laboratories in order to reach a consensus regarding quality metrics criteria and variant reporting. In the pre-standardization cross-validation round, an overall concordance of 60.98% was obtained with a great variability in selected genes and conditions across laboratories. After consensus of relevant genes and optimization of quality parameters the overall concordance rose to 85.57% in the second cross-validation round. We show that a diagnostic network with harmonized NGS analysis and reporting in seven experienced laboratories is feasible in the context of a scientific group. This cooperative nationwide strategy provides advanced molecular diagnostic for AML patients of the PETHEMA group (clinicaltrials gov. Identifier: NCT03311815).

Combined Selection System to Lower the Cutoff for Plasma Cell Enrichment Applied to iFISH Analysis in Multiple Myeloma

Multiple myeloma (MM) is a very heterogeneous disease, characterized by multiple cytogenetic aberrations on plasma cells (PC) that have been traditionally used to predict the outcome of the disease. A mayor issue on the analysis of PC is the sometimes low infiltration of these cells in the bone marrow that hampers cytogenetic studies. To solve this problem we have optimized a selection strategy based on PC immunomagnetic isolation that has allowed us to lower to 1% the minimal PC infiltration requirement without loss of purity, enabling to perform genetic analysis. In this study, we have analyzed 153 bone marrow samples of patients suspected of MM, collected from February 2015 to May 2017 by the Genetics service of the Complejo Hospitalario de Navarra. Clinical characteristics of the patients and PC immunophenotyping, conventional cytogenetics and interphase fluorescence in situ hybridization (iFISH) analyses have been assessed on these samples. In our cohort 90% of the samples had cytogenetic abnormalities, among them 50% presented immunoglobulin rearrangements, 41.9% showed 1q gains, 29.7% showed 1p deletions and 33% presented TP53 deletion.

The identification and isolation of CTCs: A biological Rubik's cube

Liquid biopsy represents an alternative to conventional biopsies for the evaluation of tumors mainly due to its easy sampling. One of the main applications is the enumeration of Circulating Tumor Cells (CTCs) to evaluate tumor progression or response to treatment. The analysis of the functional characteristics of CTCs could give us much more information about their role in order to establish a more personalized treatment for the patients. The major issue that has to be solved is the isolation of the CTC population. Multiple protocols have been developed, however none of them has demonstrated to be the definitive one. In fact, a combination of these techniques has often been performed in order to obtain a purer and viable population of CTCs. In this review we have summarized for the first time the different combinatorial approaches used in the last years to optimize the isolation of CTCs and their limitations.

Use of self-organizing maps for analyzing the behavior of canines displaced towards midline under interceptive treatment

Background

Displaced maxillary permanent canine is one of the more frequent findings in canine eruption process and it’s easy to be outlined and early diagnosed by means of x-ray images. Late diagnosis frequently needs surgery to rescue the impacted permanent canine. In many cases, interceptive treatment to redirect canine eruption is needed. However, some patients treated by interceptive means end up requiring fenestration to orthodontically guide the canine to its normal occlusal position. It would be interesting, therefore, to discover the dental characteristics of patients who will need additional surgical treatment to interceptive treatment.

Material and Methods

To study the dental characteristics associated with canine impaction, conventional statistics have traditionally been used. This approach, although serving to illustrate many features of this problem, has not provided a satisfactory response or not provided an overall idea of the characteristics of these types of patients, each one of them with their own particular set of variables. Faced with this situation, and in order to analyze the problem of impaction despite interceptive treatment, we have used an alternative method for representing the variables that have an influence on this syndrome. This method is known as Self-Organizing Maps (SOM), a method used for analyzing problems with multiple variables.

Results

We analyzed 78 patients with a PMC angulation higher than 100º. All of them were subject to interceptive treatment and in 21 cases it was necessary to undertake the above-mentioned fenestration to achieve the final eruption of the canine.

Conclusions

In this study, we describe the process of debugging variables and selecting the appropriate number of cells in SOM so as to adequately visualize the problem posed and the dental characteristics of patients with regard to a greater or lesser probability of the need for fenestration.

Key words:Interceptive orthodontic treatment, altered eruption, impacted canines, neuronal networks, self-organizing maps.

Idiotype vaccines for lymphoma: Potential factors predicting the induction of immune responses

Over the last two decades, lymphoma idiotype vaccines have been the first human cancer vaccines to show striking evidence of biological and clinical efficacy on the one hand, as well as clinical benefit on the other. More recently, however, three large-scale, independent, randomized clinical trials on idiotypic vaccination have failed to achieve their main clinical endpoints for reasons likely to depend more on flaws in each clinical trial’s study design than on each vaccination strategy per se. Independently of these considerations, a major hurdle for the development of this substantially innocuous and yet potentially very effective type of treatment has been the fact that, even to date, no factors ascertainable before vaccination have been prospectively singled out as predictors of subsequently vaccine-induced, idiotype-specific immune as well as clinical responses. The aim of this review article is precisely to analyze what has been and what could be done in this respect in order to give a greater chance of success to future trials aimed at regulatory approval of idiotype vaccines.

Idiotype vaccines for human B-cell malignancies

After twenty years of use in humans, customized idiotypic vaccination yet remains a non-approved, experimental therapeutic option for patients with lymphoma and myeloma. Potentially applicable to all B-cell malignancies whose cells express a clonal immunoglobulin or its epitopes on their surface, this treatment is designed to prevent disease recurrence or progression. Mostly used in follicular lymphoma patients so far, idiotype vaccines have clearly shown biological efficacy, clinical efficacy and clinical benefit in this setting, although no study aiming at regulatory approval of the procedure has been able to meet its main clinical endpoints. In mantle cell lymphoma, only biological efficacy has been proven for idiotypic vaccination, while in multiple myeloma a limited number of studies support the notion of biological and perhaps even clinical efficacy, although no credible evidence of clinical benefit has still emerged. Idiotype vaccines have been produced and administered in a number of substantially different manners. Therefore, the results of most clinical trials cannot be easily compared, and even less pooled together in meaningful meta-analyses. A more creative and yet scientifically sound way to design clinical trials of customized active immunotherapies will be key to the future development of idiotype vaccines, particularly considering that we currently lack any clinical or biological indicator to possibly predict which patients are more likely to respond to idiotypic vaccination from an immunologic point of view. This review aims at summarizing the multifaceted success achieved by idiotype vaccines, as well as at outlining the challenges awaiting them in the near future: how to improve feasibility, immunogenicity and efficacy, as well as how to confirm benefit and gain regulatory approval.

Quantitative detection of Helicobacter pylori in water samples by real-time PCR amplification of the cag pathogenicity island gene, cagE

AIMS

A new real-time PCR assay that simultaneously amplifies a 102-bp fragment of the cagE gene from Helicobacter pylori and a new internal positive control containing a specific sequence of the gyrB gene from Aeromonas hydrophila, was developed and validated for the detection of H. pylori in environmental samples.

METHODS AND RESULTS

The specificity, limits of detection and quantification, repeatability, reproducibility, and accuracy of the method were calculated. The resulting values confirmed the applicability of the method for the quantitative detection of H. pylori. The feasibility of the method was also evaluated by testing 13 pyloric antrum-positive biopsies and 69 water samples, including potable (10), surface (19) and wastewater (40) matrices. The results showed that all the biopsies and 3 of the 40 wastewater samples analysed were positive.

CONCLUSIONS

This real-time PCR method provides a sensitive, specific, and accurate method for the rapid quantification of H. pylori in environmental samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

The PCR diagnostic system proposed in this work, provides a suitable tool for the quantitative detection of H. pylori in environmental samples and can be useful for verifying the role of water as a potential route of its transmission.

Prolonged idiotypic vaccination against follicular lymphoma

During the last 2 decades, idiotypic vaccination has provided proof of principle of biological efficacy, clinical efficacy and clinical benefit in small follicular lymphoma trials. However, with the exception of anecdotal reports, most patients have received no more than 10 doses of their customised idiotype (Id) vaccine. Therefore, it is not known whether prolonged usage of idiotypic vaccination is safe. Since 2002, 18 previously treated patients with follicular lymphoma have received extended idiotypic vaccination at our institution outside clinical trials. Vaccination was provided as a compassionate alternative to no further treatment, and was meant to be stopped only upon complete consumption of the available patient- and tumor-specific vaccine [Id-keyhole limpet hemocyanin + granulocyte-macrophage colony-stimulating factor (Id-KLH + GM-CSF)], or in case of disease relapse or any serious non-local toxicity. So far, 18 patients have received an average of 18 doses of Id vaccine (median: 17; mean: 18; range: 10-31). Eleven patients are still actively receiving idiotypic vaccination: some of them are now over more than 6 years. Toxicity has been systematically negligible and mostly local. No patient has abandoned the vaccination program because of toxicity. Prolonged idiotypic vaccination with the soluble protein Id-KLH + GM-CSF formulation is safe and well tolerated.

[Idiotype vaccines in the treatment of follicular lymphoma: current status and future perspectives]

Follicular lymphoma is the second most prevalent non-Hodgkin lymphoma, representing 20% of all lymphomas. Follicular lymphoma is an indolent disease with a slow progression in which, although exhibiting a good response to treatment, relapse is very frequent and complete remission is not easy to maintain. Therefore, the disease is regarded as incurable. The search for new therapeutic strategies, together with a better understanding of the immune system, has led to the emergence of a new treatment named immunotherapy. Follicular lymphoma is a malignancy suitable for this kind of treatment given the fact that it is characterized by presenting a unique tumour-specific antigen: the idiotype of the monoclonal immunoglobulin displayed on the membrane of tumour cells. Several studies have been conducted to test immunotherapy as complementary to conventional treatment. In a previous study by our group, a clear benefit was evident is obtained after idiotypic vaccination, when an adequate immunization of the patient is obtained, in comparison to chemotherapy alone. In this sense, analysis is needed of whether idiotypic vaccination can produce not only long-lasting and complete remission, but even cure. It would be of great interest to consider an optimisation of the experimental design of clinical trials, an improvement of vaccine production, and the study of the molecular mechanisms of the tumour cell which modify the target immunoglobulin.

Clinical benefit associated with idiotypic vaccination in patients with follicular lymphoma

BACKGROUND

Follicular lymphoma is considered incurable, although cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy can induce sequential remissions. A patient's second complete response is typically shorter than that patient's first complete response. Idiotype vaccines can elicit specific immune responses and molecular remissions in patients with follicular lymphoma. However, a clinical benefit has never been formally proven.

METHODS

Thirty-three consecutive follicular lymphoma patients in first relapse received six monthly cycles of CHOP-like chemotherapy. Patients who achieved a second complete response were vaccinated periodically for more than 2 years with autologous lymphoma-derived idiotype protein vaccine. Specific humoral and cellular responses were assessed, and patients were followed for disease recurrence. Statistical tests were two-sided.

RESULTS

Idiotype vaccine could be produced for 25 patients who had a second complete response. In 20 patients (80%), a humoral (13/20) and/or a cellular (18/20) idiotype-specific response was detected. The median duration of the second complete response has not been reached, but it exceeds 33 months (range = 20+ to 51+ months). None of the 20 responders relapsed while undergoing active vaccination. All responders with enough follow-up for the comparison to be made experienced a second complete response that was statistically significantly (P<.0001) longer than both their first complete response (18 of 18 patients) and than the median duration of a CHOP-induced second complete response, i.e., 13 months (20 of 20 patients). The five nonresponders all had a second complete response that was shorter (median = 10 months; range = 8-13 months) than their first complete response (median = 17 months; range = 10-39 months).

CONCLUSIONS

Idiotypic vaccination induced a specific immune response in the majority of patients with follicular lymphoma. Specific immune response was associated with a dramatic and highly statistically significant increase in disease-free survival. This is the first formal demonstration of clinical benefit associated with the use of a human cancer vaccine.

Intervening sequences of regularly spaced prokaryotic repeats derive from foreign genetic elements

Prokaryotes contain short DN repeats known as CRISPR, recognizable by the regular spacing existing between the recurring units. They represent the most widely distributed family of repeats among prokaryotic genomes suggesting a biological function. The origin of the intervening sequences, at present unknown, could provide clues about their biological activities. Here we show that CRISPR spacers derive from preexisting sequences, either chromosomal or within transmissible genetic elements such as bacteriophages and conjugative plasmids. Remarkably, these extrachromosomal elements fail to infect the specific spacer-carrier strain, implying a relationship between CRISPR and immunity against targeted DNA. Bacteriophages and conjugative plasmids are involved in prokaryotic population control, evolution, and pathogenicity. All these biological traits could be influenced by the presence of specific spacers. CRISPR loci can be visualized as mosaics of a repeated unit, separated by sequences at some time present elsewhere in the cell.

Pulmonary lymphoid lesions in an experimental model of collapsing glomerulopathy in rats

The characterization of lung damage in an experimental model of collapsing glomerulopathy (CG) in rats is described.

METHODS

12 rats were divided into two groups and injected intravenously (iv) with 1 mg/saline in a final volume of 1 ml/ day in the tail vein for 5 days, with fractionated serum from control and CG subjects. Proteinuria was quantified, and the Glomerular filtration rate was calculated based on creatinine clearance (CC). Rats were sacrificed by perfusion fixation at day 5.

RESULTS

Rats injected with serum from CG patients developed proteinuria (p<0.001). A decrease in CC (0.68+/-0.19) in these rats was also observed. Glomerular tuft retraction and mesangial proliferation was observed in all rats receiving serum from the CG patients. Peribronchiolar infiltrate integrated mainly by lymphocytes, was identified in all CG rats. In some areas this infiltration disrupted the basement membrane and damaged the epithelium. No histopathological abnormalities in the kidney or lungs were found in rats receiving control serum.

CONCLUSION

Patchy pulmonary lymphoid infiltrates were found in the CG model. Up to now there was no information about pulmonary lymphoid infiltration in CG patients. Besides fluid overload due to renal insufficiency or a nephrotic syndrome, other causes of pulmonary involvement in CG patients should be explored.

Loss of FHIT protein expression is related to high proliferation, low apoptosis and worse prognosis in non-small-cell lung cancer

The fragile histidine triad (FHIT) gene, located at chromosome 3p14.2, is deleted in many solid tumors, including lung cancer. Its protein product is presumed to have tumor suppressor function. We investigated the incidence of loss of heterozygosity and loss of FHIT expression in a series of non-small-cell lung carcinomas and its correlation to apoptosis, proliferation index and prognosis. FHIT expression was determined by immunohistochemistry in formalin-fixed paraffin-embedded tissues from 54 squamous cell carcinomas (SCC) and 44 adenocarcinomas (AC) of the lung. DNA from frozen tumor and corresponding normal tissues were analyzed for allelic losses at two loci located internal (D3S1300, D3S1234) and three loci in flanking regions centromeric and telomeric (D3S1210, D3S1312, D3S1313) to the FHIT gene. Apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL). Proliferation index was determined with ki-67 and flow cytometric analysis. We correlated the results with tumor histology, prognosis and some immunohistochemical markers (p53, bcl-2, bax, c-myc, p21(waf1), cyclin-D1). FHIT expression was related to tumor histology: 52 of 54 (96.3%) SCC and 20 of 44 (45.5%) AC were negative for FHIT (P<0.0001). We found LOH at 3p14.2 in 67.8% of the 98 cases: 72.3% of SCC and 61.4% of AC. Loss of FHIT expression was associated with a higher proliferation index (ki-67, P=0.007; flow cytometry, P<0.004) and lower apoptotic index (P=0.018). LOH at FHIT gene were associated to a high proliferation (flow cytometry, P<0.001) and lower apoptotic level (P=0.043). The log-rank test demonstrated a significant inverse correlation (P=0.039) between loss of FHIT expression and patient survival. FHIT plays an important role in the development of non-small-cell lung cancer, particularly in SCC. Loss of FHIT protein is correlated with a high proliferation and low apoptotic index in tumor cells, and is an independent prognostic indicator for the clinical outcome in patients with these tumors.

PTEN protein expression correlates with PTEN gene molecular changes but not with VEGF expression in astrocytomas

PTEN gene (10q23) is a relevant tumor suppressor gene whose protein is a phosphatase involved in the control of angiogenesis of some tumors including astrocytomas. There are no studies correlating molecular changes of PTEN and the immunohistochemical expression of its protein (pPTEN) with the expression of vascular endothelial growth factor (VEGF) in astrocytomas. Fifty-six surgically resected brain gliomas, 10 grade 2, 16 grade 3, and 30 grade 4, were studied by a combined approach, consisting of (1) PCR analysis using four microsatellite markers against the PTEN gene region (10q23), (2) the FISH technique to test chromosome 10 using a pericentromeric probe, and (3) immunohistochemical evaluation of pPTEN and VEGF. Loss of heterozygosity (LOH) of PTEN was observed in 10% of fibrillary grade 2 astrocytomas and all gemistocytic ones. In high-grade tumors, LOH was more frequent in grade 4 than in grade 3 (> or =2 loci deleted, 83% and 56%, respectively). Monosomy for chromosome 10 was observed especially in high-grade tumors (6% of grade 3 and 50% of grade 4) and in 20% of grade 2 tumors, corresponding to gemistocytic astrocytomas. Results with both antibodies against PTEN were concordant: loss of cytoplasmic immunoreactivity was frequently observed according to homogeneous or heterogeneous patterns in 70% and 50% of grades 4 and 3, respectively, but not in grade 2. Immunonegativity of pPTEN was associated with PTEN gene deletion (> or =2 loci deleted) (P = 0.04) but not with monosomy. Cytoplasmic immunoreactivity against VEGF was observed in high-grade and in gemistocytic astrocytomas, but not in conventional grade 2 tumors. Tumor expression of pPTEN was not associated with immunoreactivity against VEGF when the same areas were considered. In conclusion, loss of PTEN expression is frequent in high-grade astrocytomas, but not in grade 2 tumors, and correlates with PTEN deletion and loss of chromosome 10. PTEN immunoreactivity does not correlate with VEGF expression in astrocytomas when similar areas are considered.

Opposite effects of myocardial stretch and verapamil on the complexity of the ventricular fibrillatory pattern: an experimental study

An experimental model is used to analyze the effects of ventricular stretching and verapamil on the activation patterns during VF. Ten Langendorff-perfused rabbit hearts were used to record VF activity with an epicardial multiple electrode before, during, and after stretching with an intraventricular balloon, under both control conditions and during verapamil (Vp) infusion (0.4-0.8 mumol). The analyzed parameters were dominant frequency (FrD) spectral analysis, the median (MN) of the VF intervals, and the type of activation maps during VF (I = one wavelet without block lines, II = two simultaneous wavelets with block lines, III = three or more wavelets with block lines). Stretch accelerates VF (FrD: 22.8 +/- 6.4 vs 15.2 +/- 1.0 Hz, P < 0.01; MN: 48 +/- 13 vs 68 +/- 6 ms, P < 0.01). On fitting the FrD time changes to an exponential model after applying and suppressing stretch, the time constants (stretch: 101.2 +/- 19.6 s; stretch suppression: 97.8 +/- 33.2 s) do not differ significantly. Stretching induces a significant variation in the complexity of the VF activation maps with type III increments and type I and II decrements (control: I = 17.5%, II = 50.5%, III = 32%; stretch: I = 7%, II = 36.5%, III = 56.5%, P < 0.001). Vp accelerates VF (FrD: 20.9 +/- 1.9 Hz, P < 0.001 vs control; MN: 50 +/- 5 ms, P < 0.001 vs control) and diminishes activation maps complexity (I = 25.5%, II = 60.5%, III = 14%, P < 0.001 vs control). On applying stretch during Vp perfusion, the fibrillatory process is not accelerated to any greater degree. However, type I and II map decrements and type III increments are recorded, though reaching percentages similar to control (I = 16.5%, II = 53%, III = 30.5%, NS vs control). The following conclusions were found: (1) myocardial stretching accelerates VF and increases the complexity of the VF activation pattern; (2) time changes in the FrD of VF during and upon suppressing stretch fit an exponential model with similar time constants; and (3) although stretching and verapamil accelerate the VF process, they exert opposite effects upon the complexity of the fibrillatory pattern.

Involvement of Rho GTPases in the transcriptional inhibition of preproendothelin-1 gene expression by simvastatin in vascular endothelial cells

Endothelial dysfunction is characterized by an impaired vasodilatory response to endothelial agonists as well as by alterations in adhesion and coagulation processes. 3-Hydroxy-3-methylglutaryl-CoA reductase inhibitors (statins) have been shown to be useful in the reversal of endothelial dysfunction, an effect that may be independent of the reduction in cholesterol levels. Both the L-arginine-nitric oxide-cGMP and endothelin pathways are involved in the regulation of vascular tone. Here, we show that the basal transcription rate of the preproendothelin-1 gene was decreased by simvastatin (10 micromol/L) in bovine aortic endothelial cells. Transfection studies with the preproendothelin-1 gene promoter showed that mevalonate (100 micromol/L) was able to prevent the inhibitory effect mediated by simvastatin. Protein geranylgeranylation, but not farnesylation, proved to be crucial for a correct expression of the preproendothelin-1 gene. The C3 exotoxin from Clostridium botulinum that selectively inactivates Rho GTPases, the processing of which involves geranylgeranylation, reproduced the inhibitory effect of simvastatin on the expression of preproendothelin-1. Overexpression of dominant-negative mutants of RhoA and RhoB led to a significant reduction in the preproendothelin-1 promoter activity, whereas the expression of wild-type and constitutively active forms of these proteins resulted in an increase, in support that Rho proteins are required for the basal expression of the preproendothelin-1 gene. Finally, we show that the Rho-dependent activation of the preproendothelin-1 gene transcription was inhibited by simvastatin. Thus, the control of vascular tone and proliferative response mediated by endothelin-1 is regulated at multiple levels, among which the Rho proteins play an essential role.

[Usefulness of determining low-avidity IgG antibodies in the diagnosis of primary rubella infection in pregnant women]

BACKGROUND

It is necessary to have an easy and quickly test to distinguish "false positive" rubella IgM results and residual antibodies from the antibodies produced in the primary infection, in pregnant women. The avidity of IgG antibodies test seems to differentiate between primary rubella infection and past infections, reinfections or postvaccination, showing its utility in the diagnosis of primary infection in other infectious diseases.

METHOD

For 30 months, 178 sera from 157 patients with clinical and/or epidemiological rubella suspicion or with a positive rubella IgM result as result of an accidental serological finding, were remitted to our laboratory for a serological follow up. We distinguished 3 patient groups: outbreak group, 112; pregnant women, 36, and newborn 11. Rubella IgM antibodies by indirect EIA previous the rheumatoid factor absorption; IgG antibodies of low avidity by indirect EIA previous treatment of serum with 6 M urea, were detected in the sera. It considered a positive result, a rubella avidity index (AI) < 50%.

RESULTS

In the epidemic outbreak group, 90.2% of the patients were not vaccinated. 80% of cases occurred in young men between 14 an 20 years old. From 109 patients (97.3%) with rubella IgG antibodies, 92 (84.4%) showed AI-IgG lower than 50%. In this group, the mean rate of AI-IgG rubella was 29.0%. In the pregnant women group, except for two of them, rubella IgM antibodies were an accidental finding in a serological pregnancy screening. Thirty patients (83.8%) showed AI-IgG rubella > 50%. The two pregnant women who had evidence of clinical and epidemiological rubella showed AI-IgG rubella of 37.4% and 20.9%. Another four pregnant women showed AI-IgG rubella close to cut-off (44.7-49.0%). The mean AI-IgG rubella in this group was 71.8%. The mean AI-IgG Rubella between the epidemic outbreak group and the pregnant women group, 29.0 and 71.8% respectively, was statistical significance (p < 0.001).

CONCLUSIONS

The avidity IgG test is simple and quickly, and it allow to exclude most of positive results because of residual IgM antibodies and false reactive.

[The experience of the search for Lyme disease in the eastern Canary Islands]

BACKGROUND

The eastern region of Canary Islands presents certain climatic and atmospheric conditions which differentiate it from the accepted parameters in cases of Lyme disease. We present a serologic study of patients with clinical syndrome which is potentially compatible with Lyme disease, in an effort to clarify the presence of this disorder region.

MATERIAL AND METHODS

We assayed type IgG and IgM antibodies against the flagellin antigen of the native Borrelia burgdorferii using indirect enzymeimmunoassay (EIA) as a screening technique. In the serum presenting positive screening we confirmed this result with immunoblot (IB) type IgG and/or IgM with synthetic peptides for the antigenic epitopes p14, p41, p100, OspA and OspC. We review the clinical history of the patients with reactive sera.

RESULTS

We studied a sample group of 1,452 patients considered clinically compatible with Lyme disease over a 42-months period, presenting the screening results for serologic positive 47 (3.2%). From this sample, 24 (1.65%) were IB reactive, independent of the type of immunoglobulin. Only two fulfilled the criteria of both IB-IgM positive, one with antibodies against OspC and p41 proteins finally diagnosed as arteriosclerotic encephalopathy suboccipital Binswanger and another with antibodies against p100 and p41 proteins, diagnosed as presenting a primary cytomegalovirus disease. The bands that, most often lead to reactive IB were p41 and p14. Of the 24 patients who presented reactive IB, 14 (58.3%) also presented other previous data wich produced the false positives, 8 with autoimmune disease, 5 viral infectious and one infection due to Treponema pallidum.

CONCLUSION

Due to the lack of studies carried out in this field which would verify or rule out an epidemiologic chain in our region, our serologic and clinical data put the eastern Canary Islands in doubt as an endemic area of Lyme disease.

Purification and characterization of guanine nucleotide-exchange factor, eIF-2B, and p37 calmodulin-binding protein from calf brain

Eukaryotic initiation factor 2B, or guanine nucleotide-exchange factor, has been purified for the first time from the brain by a novel procedure that allows the purification of initiation factor 2 as well and uses a salt wash postmicrosomal supernatant as starting material. The procedure includes a three-part chromatographic step in heparin-Sepharose and in SP-5PW and diethylaminoethyl-5PW ion-exchange high-performance chromatographies. The purification of the factors was followed by measuring activity in the guanine nucleotide-exchange assay and the capacity of initiation factor 2 to form a ternary complex with the initiation form of methionyl-tRNA and GTP. The method yields guanine nucleotide-exchange factor (75%) and highly purified initiation factor 2 (> 95%), which are separated in the last step. The exchange factor from the brain is a multimeric protein with five subunits of molecular masses of 82, 65, 52, 42, and 30 kDa; it stimulates ternary complex formation in the presence of GDP, and this activity is inhibited by N-ethylmaleimide. A 37-kDa protein that copurifies with initiation factors is characterized in this study as a new calmodulin-binding protein (p37); it is highly phosphorylated by casein kinase activities and can comigrate with the alpha subunit of initiation factor 2 under standard sodium dodecyl sulfate electrophoresis conditions.

William P. Letchworth: philanthropist and pioneer epileptologist

Although neither a physician nor a scientist, William Pryor Letchworth significantly improved the care and treatment of epileptics at the beginning of this century. As commissioner of the New York State Board of Charities and later president, he established Craig Colony, America's first comprehensive epilepsy facility. In Care and Treatment of Epileptics, he summarized contemporary medical and social knowledge of epilepsy. As cofounder and president of the National Association for the Study of Epilepsy, he introduced from Europe his improvements of the colony plan of construction and financed Transactions, the society's scholarly journal. He combined a sensitivity to the needs of the unfortunate with the resolve of a successful businessman. Although William Pryor Letchworth is remembered for his philanthropy and the park in western New York that bears his name, his signal contributions to modern concepts of epilepsy are unknown to most physicians. This article will acquaint readers with the life and accomplishments of this philanthropist and pioneer epileptologist.

Association of intracranial meningioma with arteriovenous malformation

Simultaneous occurrence of a cerebral arteriovenous malformation and a primary brain tumor is rare. A case of a left occipital meningioma and a right parietotemporal arteriovenous malformation is reported. Clinical, radiological, and postmortem findings are described. Thirty previous reports of arteriovenous malformations associated with primary brain tumors are reviewed. In 18 cases the two lesions were intermixed or in close proximity. This spatial relationship between the lesions suggests more than a coincidental association. Several hypotheses are proposed to explain common causal connections.

The neurophysiological profile of vitamin B12 deficiency

Reports of the incidence and severity of physiological abnormalities of vitamin B12 deficiency sharply differ. To resolve these controversies we performed evoked response and nerve conduction studies in 10 males with vitamin B12 deficiency. The minimum criteria for this diagnosis were diminished position and vibration sensation and vitamin B12 levels less than 220 pg/ml. We found normal BAERs in 9/10 patients. The central interpeak latencies of the median and peroneal SERs were abnormal in 4/10 and 8/8 patients, respectively. The VERs were abnormal in 7/10 patients. We found absent or diminished amplitudes of sural sensory and peroneal motor action potentials in 8/10 patients. Abnormal peroneal F response chronodispersion was present in 7/10 patients. Nerve conduction velocities (NCV) were normal in 9/10 patients. EMG demonstrated abnormalities consistent with denervation in lower extremity muscles in 8/10 patients. These studies present a profile of vitamin B12 deficiency: essentially normal BAERs, mildly abnormal VERs and median SERs, and markedly abnormal peroneal SERs. NCV studies are consistent with sensory-motor axonopathy.

Pupil-sparing oculomotor palsy caused by fusiform arteriosclerotic aneurysm of the basilar artery--a case report

Paresis of the oculomotor nerve is a very rare complication of an unruptured arteriosclerotic fusiform aneurysm of the basilar artery. A handful of cases are described in the world literature. A fifty-four-year-old man with a history of hypertension and diabetes mellitus presented with painless partial oculomotor palsy of sudden onset. A cerebral angiogram demonstrated a tortuous fusiform deformity of the basilar artery and the origin of the posterior cerebral arteries, indicative of an arteriosclerotic aneurysmal dilation. A sudden onset of a pupil-sparing ophthalmoplegia is the typical history of a microvascular infarct of the third nerve, whereas pupillary sparing in aneurysmal oculomotor paresis is a very rare event. Special emphasis has been placed on the pupillary size as a guide for the indication of arteriography. The many exceptions to this rule suggest that cerebral arteriography may be indicated more often than generally believed.

Auditory and somatosensory evoked potentials in a case of "locked-in" syndrome: a clinical and pathological study

Brainstem auditory evoked potentials were bilaterally normal, and somatosensory evoked potentials were unilaterally abnormal in a patient with a large pontine infarct causing a "locked-in" syndrome. In the post mortem examination, the lesion extended unilaterally into the pontine tegmentum, partially involving the left medial lemniscus. The P14 potential was absent and the N20 potential was diminished in amplitude with right median nerve stimulation. The origin of the P14 potential has been debated in the literature. This case provides evidence for the P14 generator being located at the pontine level, in relation to a lemniscal area above the decussation of the somatosensory pathway. Evoked potentials can help to determine the tegmental extension of the pontine infarcts in the "locked-in" syndrome, especially in patients unable to cooperate with clinical examination.

Asymmetrical growth of scalp hair in syringomyelia

Trophic alterations in the skin take place consequent to interruption of its motor, sensory, and autonomic innervation. The hair in denervated areas is often less abundant and grows more slowly. Syringomyelia is a common cause of cutaneous trophic alterations that are often unilateral. They occur predominantly in the upper extremities and seldom involve the skin over the face and scalp. A patient with syringomyelia exhibited a unilateral impairment of pain and temperature sensation in the entire right side of the scalp. A dissimilarity of hair length between the right and left side of the scalp was noticed, with a sharp demarcation along the midline. This peculiar trophic change has not been previously described in the medical literature.

Thermography as a predictor of the more involved side in bilateral carotid disease: case history

Contact thermography using liquid crystals provides a simple, inexpensive method of evaluating carotid disease. It does not duplicate information provided by other noninvasive methods, because, whereas Dopplers give an indication of flow and degree of stenosis in the artery, thermography measures the actual hypoperfusion as demonstrated by diminished temperature in areas of the forehead supplied by branches of the ophthalmic artery. A 74-year-old man presented with bilateral carotid distribution TIAs. Carotid Dopplers and angiography revealed 99% occlusion of both internal carotid arteries. Contact thermography showed diminished temperature in the right supraorbital artery territory. The patient subsequently underwent carotid endarterectomy. Following induction of anesthesia but prior to carotid clamping, the patient became transiently hypotensive. Intraoperative EEG monitoring showed marked attenuation of the background rhythm on the right with preservation of background on the left. Normal rhythm was quickly restored with pharmacologic restoration of the blood pressure. This case illustrates the usefulness of thermography, which predicted the hemisphere in jeopardy when Dopplers and angiography showed equal bilateral disease.

Detection of a thermostable brain antigen in the circulation of patients after cerebrovascular accident

Enzyme immunoassay was developed with a thermostable antigen of human brain and its corresponding antiserum of rabbit origin. Inhibition of this assay proved to be a sensitive technique for detection of this antigen in the circulation. Using the inhibition test, we tested 170 serum samples originating from 42 patients with cerebrovascular accident (CVA), 166 sera from 166 patients with other neurological disorders, and 56 sera from 56 normal subjects. Fourteen patients with CVA were found to be "positive' and 28 "negative'. Positive results in inhibition tests were first noted within 1-2 days after CVA and they appeared to decline to negative values within 3-5 weeks after CVA. None of the sera from subjects without CVA were positive.