Endocarditis bacteriana a propósito de un caso / Bacterial endocarditis case report

OBJETIVO: informar acerca de un caso de endocarditis bacteriana. Paciente varón de 34 años de edad, con único antecedente de rinitis alérgica con tratamiento irregular. Él es procedente de Valparaiso Chile, se encuentra en sus vacaciones en la ciudad de La Paz, acude al servicio de medicina interna ­ emergencias, con clínica compatible con edema agudo de pulmón de la altura y edema cerebral de la altura, asociado a sepsis de foco pulmonar, que progresa a choque séptico, durante su internación intercurre con alzas térmicas continuas, asociado a hallazgo ecocardiográfico de vegetación en ventrículo derecho con hemocultivo positivo, por lo que se llega al diagnóstico de endocarditis bacteriana, se realizó el tratamiento correspondiente, y resolución del cuadro.

OBJECTIVE: to report a case of bacterial endocarditis A 34-year-old male patient with a unique history of allergic rhinitis with irregular treatment. He comes from Valparaiso Chile, is on vacation in the city of La Paz, goes to the service of internal medicine - emergencies with compatible clinical with acute pulmonary edema of height and cerebral edema of height, associated with sepsis of focus pulmonary disease, which progresses to septic shock, during internment with continuous hyperthermia, associated vegetation in right ventricle for echocardiography, also positive blood culture, so that a diagnosis of bacterial endocarditis is reached, Corresponding treatment was carried out, and resolution of pathology..

SEOM clinical guideline on hereditary colorectal cancer (2019).

In the last 2 decades, clinical genetics on hereditary colorectal syndromes has shifted from just a molecular characterization of the different syndromes to the estimation of the individual risk of cancer and appropriate risk reduction strategies. In the last years, new specific therapies for some subgroups of patients have emerged as very effective alternatives. At the same time, germline multigene panel testing by next-generation sequencing (NGS) technology has become the new gold standard for molecular genetics.

The value of cough peak flow measurements in the assessment of extubation or decannulation readiness.

Insufficient cough strength has a major role in extubation and decannulation outcomes. Cough capacity can be easily evaluated by measuring flows during coughing. Values vary depending on whether cough flows are measured through the mouth or through a tracheostomy or endotracheal tube. It is important to standardize these measurements and start using them routinely in the extubation and decannulation processes. Values of cough peak flow >160 L/min measured at the mouth or a value of cough PEF >60 L/min measured at the endotracheal tube suggest successful decannulation or extubation.

Identification of a founder EPCAM deletion in Spanish Lynch syndrome families.

Germline deletions at the 3'-end of EPCAM have been involved in the etiology of Lynch syndrome (LS). The aim of this study was to characterize at the molecular level Spanish families harboring EPCAM deletions. Non-commercial multiplex ligation-dependent probe amplification (MLPA) probes and long-range polymerase chain reaction (PCR) amplification were used to characterize each deletion. Haplotyping was performed by analyzing eight microsatellite markers and five MSH2single nucleotide polymorphisms (SNPs). Methylation of MSH2 was analyzed by methylation specific-MLPA. Tumors diagnosed in seven Spanish families harboring EPCAM deletions were almost exclusively colorectal. Mosaicism in MSH2 methylation was observed in EPCAM deletion carrier samples, being average methylation levels higher in normal colon and colorectal tumors (27.6% and 31.1%), than in lymphocytes and oral mucosa (1.1% and 0.7%). Three families shared the deletion c.858 + 2568_*4596del, with a common haplotype comprising 9.9 Mb. In two families the novel EPCAM deletion c.858 + 2488_*7469del was identified. This study provides knowledge on the clinical and molecular characteristics of mosaic MSH2 epimutations. The identification of an EPCAM founder mutation has useful implications for the molecular diagnosis of LS in Spain.

Clinically important molecular features of Peruvian colorectal tumours: high prevalence of DNA mismatch repair deficiency and low incidence of KRAS mutations.

BACKGROUND: The incidence of colorectal cancer (CRC) in Peru has been increasing, and no data have been published on the molecular features. We explored the most relevant genetic events involved in colorectal carcinogenesis, with clinical implications. METHODS: Using immunohistochemistry for mismatch-repair (MMR) proteins (MLH1, MSH2, MSH6, and PMS2) and microsatellite instability analysis, we evaluated the status of 90 non-selected CRC Peruvian patients followed in a nationwide reference hospital for cancer (INEN, Lima). Tumours with loss of hMLH1 were evaluated further for hMLH1 promoter hypermethylation and all cases were evaluated for the presence of KRAS and BRAF-V600E mutations. RESULTS: MMR deficiency was found in 35 (38.8%) patients. We identified an unexpected association between MMR deficiency and older age. Among the 14 cases with loss of MLH1, 10 samples exhibited hypermethylation. Of the 90 cases evaluated, 15 (16.7%) carried KRAS mutations; we found one previously unreported mutation (G13R). CONCLUSIONS: Peruvian CRC tumours exhibited the highest prevalence of MMR deficiency reported to date. The expected hereditary component was also high. The age of onset of these MMR deficient tumours was greater than that observed for non-MMR deficient cases, suggesting the ineffectiveness of the Bethesda criteria for Lynch syndrome screening in Peru. Prospective studies are warranted to define the molecular characteristics of CRC in this population.

Circulating tumour cell analysis as an early marker for relapse in stage II and III colorectal cancer patients: a pilot study

INTRODUCTION: Recent studies have identified both the prognostic and predictive utility of determining the number of circulating tumour cells (CTC) in patients with solid cancers. MATERIAL AND METHODS: In the present pilot study we evaluated the ability of two different methods to isolate CTC in combination with two strategies to enumerate CTC from patients with stages II and III surgically treated colorectal cancer (CRC). First, we used two systems for tumour cell enrichment (differential centrifugation and immunomagnetic beads), combined with two methods to enumerate CTC (real-time PCR and fl ow cytometry), to determine the most efficient combination. These experiments were performed in a model system using serial dilutions of HT29 tumour cell lines with lymphocytes. Then, CTC analysis using the technical approach selected before was performed in 109 blood samples from 16 stage II and III CRC patients during chemotherapy treatment and follow-up. RESULTS: Immunomagnetic beads followed by flow cytometry was the most efficient combination (ED=60.53; p=0.5). Two cases out of 16 patients analysed had clinical tumour relapse. In both, we detected a significant increase of CTC five and six months, respectively, before the relapse was clinically evidenced. An increase of CTC was also observed in another case without clinical evidence of relapse. The remaining cases (13) had very few or no detectable CTC and no clinical evidence of relapse (p=0.029). CONCLUSIONS: Changes in CTC numbers during follow-up might predict tumour relapse. Further evaluation of CTC prognostic and predictive value in patients with early CRC is warranted (AU)

Biallelic MYH germline mutations as cause of Muir-Torre syndrome.

Muir-Torre syndrome is a rare, inherited disease predisposing of gastrointestinal and cutaneous tumours, such as keratoacanthomas and sebaceous gland adenomas. Muir-Torre syndrome is usually inherited in an autosomal dominant fashion and associated with mutations in the mismatch repair genes, predominantly in MLH1 and MSH2 genes. This report describes a man who has multiple adenomatous colon polyps, a gastric cancer, multiple colorectal cancers and sebaceous adenomas caused by biallelic MYH germline mutations. This finding demonstrates that MYH gene analysis should be considered in Muir-Torre families where no mismatch repair gene mutations have been found. Furthermore, this report contributes to characterize the clinical phenotype caused by biallelic mutations in MYH gene, which may share with other hereditary colon cancer syndromes.

Real-time PCR with internal amplification control for detecting tuberculosis: method design and validation.

Real-time PCR has been a major development in the diagnosis of tuberculosis. However, most tests do not include an internal amplification control (IAC), which therefore limits it clinical application. In this study a new, easy to perform real-time PCR test with IAC was designed and validated in clinical samples. The primers amplified a 163-bp fragment of IS6110 of Mycobacterium tuberculosis and the IAC was designed with a fragment of a different microorganism (Chlamydia trachomatis). The interassay and intraassay variation of this test were very low (0.45-1.65% and 0.18-1.80%, respectively). The detection accuracy was validated in 50 samples (25 urine, 25 sputum) with different concentrations of M. tuberculosis, 18 clinical isolates of non-tuberculous mycobacteria and 148 samples with clinical suspicion of pulmonary tuberculosis. The specificity was 100%. The detection limit of this PCR test without IAC was approximately 15 bacteria and with IAC approximately 32 bacteria. This real-time PCR with IAC assay can improve the detection of M. tuberculosis and contribute to standardization of this diagnostic technique.

Tumour cells resistance in cancer therapy

Resistance to chemotherapeutic drugs presents a big caveat for cancer treatment. In this review we will describe the molecular mechanisms involved in chemoresistance, discussing the mechanisms of resistance related to tumour microenvironment, as well as their intracellular mechanisms. Chemoresistance can also appear as a consequence to treatments with new anticancer drugs. In this sense, we will exemplify this type of resistance discussing mechanisms of action of epidermal growth factor receptor (EGFR) inhibitors. We conclude that the main problem of chemoresistance is due to its pleiotropic and multifactorial nature(AU)

Molecular biology of exocrine pancreatic cancer.

Exocrine pancreatic cancer is one of the neoplasias with a worse prognosis, with conventional treatments having little impact on disease outcome. Research and genomic high-throughput technology is continuously expanding our knowledge of pancreas cancer biology. Characterization of genetic and epigenetic alterations in pancreatic tumors has allowed a better understanding of the progression model of the disease at the molecular level. The development of new therapeutic approaches with target- oriented agents is been tested in the preclinical and clinical settings. This review updates the current available data on pancreatic cancer molecular biology.

Multidrug resistance-associated protein (MRP1) gene is strongly expressed in gastric carcinomas. Analysis by immunohistochemistry and real-time quantitative RT-PCR.

AIMS: To assess MRP1 protein and MRP1 mRNA levels in gastric carcinomas and in non-neoplastic mucosa remote from the tumours. MRP1 gene expression may play a role in the complex pattern of chemoresistance present in gastric carcinomas. METHODS AND RESULTS: A total of 57 carcinomas and respective gastric tissues were included for immunohistochemical assessment with the anti-MRP1 monoclonal antibodies MRPr1 and QCRL-1. Of these, 35 tumour and gastric mucosa tissues were also assessed by real-time quantitative reverse transcriptase-polymerase chain reaction. Medium or high MRP1 protein expression was detected in 89% and 77% of carcinomas and in 96% and 93% of non-neoplastic gastric mucosa by MRPr1and QCRL-1, respectively. No difference in MRP1 mRNA levels was detected between carcinomas and non-neoplastic gastric mucosa tissues in 77% of the patients. A significant correlation was found between MRP1 mRNA level and protein expression detected in carcinomas related to non-neoplastic gastric mucosa, although they were non-concordant in 29% of the patients. CONCLUSIONS: MRP1 gene is usually expressed in most gastric carcinomas and does not differ substantially from that observed in non-neoplastic gastric mucosa remote from the tumour. However, a decrease in MRP1 gene expression is found in some carcinomas. For accurate assessment of changes in MRP1 expression between tumour and normal tissues both protein and mRNA detection are necessary.

Functional significance of concomitant inactivation of hMLH1 and hMSH6 in tumor cells of the microsatellite mutator phenotype.

Genetic or epigenetic inactivation of one of the DNA mismatch repair (MMR) genes in tumor precursor cells causes a profound mutator phenotype, known as the microsatellite mutator phenotype (MMP). This mutator phenotype induces mutations not only in cancer genes that drive tumorigenesis but also in other DNA repair genes. The functional significance of these successive DNA repair gene mutations, however, has not been substantiated. Here we show that the concomitant inactivation of two DNA MMR genes (hMLH1 and hMSH6) increases the mutator phenotype. We isolated cell clones of the SW48 MMP-positive cell line with either active or inactive hMSH6. All of these clones lacked expression of hMLH1 because of promoter hypermethylation. Compared with inactivation of hMLH1 alone, the additional inactivation of hMSH6 produced a higher mutation rate and a different spectrum of mutations in the endogenous hprt gene. These results confirm our model that the mutator phenotype can increase during tumorigenesis by the consecutive inactivation of different members of the DNA MMR system. Thus, a stronger mutator phenotype accelerates the accumulation of mutations in target cancer genes, which, in turn, speeds up tumor progression. The results of this study also have significant impact on our understanding of the mechanism of DNA MMR.

Comparative genomic hybridization and amplotyping by arbitrarily primed PCR in stage A B-CLL.

Cytogenetic analysis is useful in the diagnosis and to assess prognosis of B-cell chronic lymphocytic leukemia (B-CLL). However, successful cytogenetics by standard techniques has been hindered by the low in vitro mitotic activity of the malignant B-cell population. Fluorescence in situ hybridization (FISH) has become a useful tool, but it does not provide an overall view of the aberrations. To overcome this hurdle, two DNA-based techniques have been tested in the present study: comparative genomic hybridization (CGH) and amplotyping by arbitrarily primed PCR (AP-PCR). Comparative genomic hybridization resolution depends upon the 400-bands of the human standard karyotype. AP-PCR allows detection of allelic losses and gains in tumor cells by PCR fingerprinting, thus its resolution is at the molecular level. Both techniques were performed in 23 patients with stage A B-CLL at diagnosis. The results were compared with FISH. The sensitivity of AP-PCR was greater than CGH (62% vs. 43%). The use of CGH combined with AP-PCR allowed to detect genetic abnormalities in 79% (15/19) of patients in whom G-banding was not informative, providing a global view of the aberrations in a sole experiment. This study shows that combining these two methods with FISH, makes possible a more precise genetic characterization of patients with B-CLL.

[Reabsorption syndrome. Report of a case]. / Síndrome de reabsorción. Presentación de un caso.

OBJECTIVE: To report a case of TURP syndrome and emphasize the importance of early diagnosis. METHODS: A case of reabsorption syndrome in a patient that underwent transurethral resection under spinal anesthesia is presented. RESULTS: Reabsorption syndrome (TURP syndrome) is manifested by neurological and hemodynamic changes resulting from absorption of irrigating fluid used during transurethral resection of the prostate. This complication presented in a patient undergoing elective surgery and with no additional risk factors. CONCLUSIONS: Since it is impossible to prevent this complication of TUR, spinal anesthesia should be utilized whenever possible because it permits early detection before important complications develop.

Notl-Msell methylation-sensitive amplied fragment length polymorhism for DNA methylation analysis of human cancers.

We have applied a methylation-sensitive restriction endonuclease, NotI, to the existing amplified fragment length polymorphism (AFLP) method and developed NotI-MseI methylation-sensitive-AFLP (MS-AFLP). NotI-MseI MS-AFLP allows the analysis of DNA methylation alterations at the NotI sites scattered over the genome. Hypermethylation and hypomethylation are visualized by the decrease and increase in the band intensity of DNA fingerprints. Identification of consistent changes can be facilitated through parallel electrophoresis of multiple samples. DNA fragments exhibiting alterations can be cloned from fingerprint bands by amplification of gel-eluted DNA with the same pair of primers used for radioactive fingerprint presentation. Fluorescent NotI-MseI MS-AFLP offers a safer method of studying the alterations in DNA methylation, and may be applied to the hybridization of DNA microarrays in the future. Using NotI-MseI MS-AFLP, we observed frequent hypomethylation of a satellite DNA repeat sequence in a majority of breast tumors.

A new beta 2 microglobulin mutation found in a melanoma tumor cell line.

Beta2 microglobulin mutations are an important mechanism for HLA class I total loss, (phenotype No. I) and have been described in colon carcinomas, melanomas and lymphomas. We describe a new beta2 microglobulin mutation detected in the melanoma cell line GR-34. The new mutation reported here was identified as a deletion of 4 bases (TTCT) in the highly repetitive sequence CTCTCTCTTTCT located in the leader sequence of the beta2 microglobulin gene at codon 15-16 of exon 1. The mutation produces a frameshift in the open reading frame sequence with the appearance of a stop codon at position 42. We also demonstrate that the second beta2 microglobulin gene is deleted. Comparisons with beta2 microglobulin mutations in other tumor cell lines suggest a mutation hot spot in exon 1.

Molecular karyotype (amplotype) of metastatic colorectal cancer by unbiased arbitrarily primed PCR DNA fingerprinting.

Genomic instability characterizes the aneuploid cancer cell. Losses of genetic material are critical in cancer by exposing recessive mutations in tumor suppressor genes. Gains of genetic material also may lead to overexpression of genes contributing to tumor progression either in the presence or absence of mutation. However, the detection of moderate gains (such as tri-tetraploidy) has been a challenge in cancer research. Unbiased DNA fingerprinting by the arbitrarily primed PCR allows the detection of moderate gains (in addition to losses) of DNA sequences of known chromosomal localization. We have generated in this manner a molecular karyotype of metastatic colon cancer. This amplotype shows that sequences from several chromosomes undergo both losses (1, 4, 9, 14, and 18) and gains (6, 7, 12, and 20) in over half of the tumors. Moreover, gains of sequences from chromosomes 8 and 13 occurred in most tumors, indicating the existence in these chromosomes of positive regulators of cell growth or survival that are under strong positive selection during tumor progression. We conclude that overrepresentation of these chromosomal regions is a critical step for metastatic colorectal cancer. Comparative amplotype analysis from primary and metastatic tumors suggest the existence in chromosome 4 of gene(s) whose loss is specifically selected in cells that reach the metastatic stage.