Culprit lesion and jeopardized myocardium: correlation between coronary angiography and single-photon emission computed tomography

BACKGROUND

The term "culprit lesion" is used to designate the coronary stenosis responsible for the symptoms of the patient with coronary artery disease. Its detection is essential when partial revascularization is contemplated. The term "jeopardized myocardium" is commonly used to mean the amount of myocardium put in danger by all the stenotic lesions; however, it should be restricted to the amount of myocardium that could become infarcted if only the most severe stenoses were occluded.

HYPOTHESIS

The aim of this study was to investigate (1) the agreement between coronary myocardial single-photon emission computed tomography (SPECT) and coronary angiography for the identification of the culprit lesion, and (2) the correlation of the two studies in the quantification of jeopardized myocardium.

METHODS

In all, 159 patients with coronary artery disease without previous myocardial infarction were included in the study. A score for myocardial SPECT was correlated with the angiographic scores by Califf and Gensini and with the authors' score which includes adjustment for collateral circulation.

RESULTS

The agreement between coronary angiography and SPECT for the diagnosis of the culprit lesion was 84% (87/104). The correlations between the scores of angiography and SPECT to assess jeopardized myocardium when all coronary stenoses were taken into account were significant (p < 0.0001), but their coefficients were suboptimal (r = 0.48 for Califf, r = 0.48 for Gensini, and r = 0.65 for the authors' score). When only the jeopardized myocardium resulting from the culprit lesion was considered, the correlation clearly improved (r = 0.85).

CONCLUSION

Thus, in 84% of patients with multivessel disease, an agreement between coronary angiography and myocardial SPECT for the diagnosis of the culprit lesion was observed. The correlation between these techniques for the quantification of jeopardized myocardium from the culprit lesion was satisfactory.

Prognostic factors in the diagnostic work-up of cancer patients in an internal medicine department: does age matter?

INTRODUCTION

Increasing life expectancy in the general population has led to a rise in the incidence of cancer and new challenges with regard to the diagnosis, therapy and prognosis of this disease.

AIM

To assess prognostic factors in the initial work-up of patients ultimately diagnosed with cancer in an Internal Medicine Service, particularly those related with age.

PATIENTS AND METHODS

A prospective study was undertaken with 224 patients ultimately diagnosed with cancer, as confirmed by histological or cytological study. The neoplasms included respiratory, gastrointestinal, genitourinary, metastatic adenocarcinoma of unknown origin, gynaecological, hepatobiliary and others. Before reaching the diagnosis, the following factors were investigated in all patients: functional status [Karnofsky Performance Status (KPS)], comorbidity (Charlson scale), body mass index (BMI), serum cholesterol and albumin concentrations, cognitive level (Mini-mental test), quality of life (Short Form 36 questionnaire), and extension of the disease according to established criteria. Survival at 1 year was analysed. Statistical analyses were done with spss 11.0 for Windows, using a forward stepwise (likelihood ratio) method to construct the model and a Cox multivariate model for the survival analysis.

RESULTS

A total of 224 patients, 167 men (74.5%) and 57 women (25.5%), with a mean age of 66.1 +/- 12.3 years were studied. KPS was >or= 70 in 84% and comorbidity was zero or one in 74%. BMI was 24.25 +/- 4.3, cholesterol 180.7 +/- 4.3, albumin 3.32 +/- 0.5 and Mini-mental score 25.4 +/- 3.7. Metastasis was seen in 131 patients (58.5%) and local disease in 93 cases (41.5%). One-year survival was 38.8% (87 patients) with a mean of 203.8 +/- 143 days. In the Cox analysis, the independent predictive factors for survival were KPS [hazard ratio (HR) = 0.951; 95% CI = 0.930-0.974; p < 0.01], metastatic dissemination (HR = 2.422; 95% CI = 1.643-3.571; p < 0.01), physical quality of life (HR = 0.978; 95% CI = 0.962-0.995; p < 0.01) and albumin (HR = 0.653; 95% CI = 0.455-0.936; p < 0.01).

CONCLUSIONS

In the initial work-up of patients ultimately diagnosed with cancer in an Internal Medicine Service, functional status, dissemination, the physical component in the quality of life scale and serum albumin levels were independent prognostic factors for survival. Age was not an independent prognostic factor and should not be used as a basis for adopting diagnostic or therapeutic decisions in these patients.

Coxsackieviruses and quasispecies theory: evolution of enteroviruses

Enterovirus populations display quasispecies dynamics, characterized by high rates of mutation and recombination, followed by competition, selection, and random drift acting on heterogeneous mutant spectra. Direct experimental evidence indicates that high mutation rates and complex mutant spectra can serve for the adaptation of enteroviruses to complex environments. Studies with the RNA-dependent RNA polymerase of picornaviruses suggest that multiple enzyme sites may influence the template-copying fidelity (incorporation of incorrect vs correct nucleotide) during RNA replication. Mutation and recombination are an unavoidable consequence of the molecular mechanisms inherent to the process of viral genome replication and underlie the diversification of enterovirus genomes as they multiply in human and animal hosts. The diversity of disease manifestations associated with closely related enteroviruses is probably attributable to profound biological effects of some mutations that, because of their limited number, do not necessarily affect the phylogenetic position of the virus. The combination of highly dynamic mutant spectra with unpredictable alterations of biological behavior by minimal genetic change defies classical classification schemes. The result is the need to update the grouping of enteroviruses quite frequently into genetic and serological types and subtypes. The tolerance of enterovirus genomes to remain replication-competent despite multiple mutation and recombination events encourages the engineering of live-attenuated vaccines. Also, the application of quasispecies theory to an understanding of the limits of viral genomes to accept mutations, together with an increasingly deeper understanding of the mechanisms of mutagenesis by nucleoside analogs, has paved the way for the application of lethal mutagenesis as a new antiviral strategy.

Rapid viral quasispecies evolution: implications for vaccine and drug strategies

High mutation rates occurring during replication allow RNA viruses to evolve rapidly and adapt continuously to new environments. This poses an enormous challenge to vaccine and drug development which, to be effective, must consid RNA virus variability and follow approaches that minimize the probability of escape or resistant mutants arising.

Impact of protein kinase PKR in cell biology: from antiviral to antiproliferative action

The double-stranded RNA-dependent protein kinase PKR is a critical mediator of the antiproliferative and antiviral effects exerted by interferons. Not only is PKR an effector molecule on the cellular response to double-stranded RNA, but it also integrates signals in response to Toll-like receptor activation, growth factors, and diverse cellular stresses. In this review, we provide a detailed picture on how signaling downstream of PKR unfolds and what are the ultimate consequences for the cell fate. PKR activation affects both transcription and translation. PKR phosphorylation of the alpha subunit of eukaryotic initiation factor 2 results in a blockade on translation initiation. However, PKR cannot avoid the translation of some cellular and viral mRNAs bearing special features in their 5' untranslated regions. In addition, PKR affects diverse transcriptional factors such as interferon regulatory factor 1, STATs, p53, activating transcription factor 3, and NF-kappaB. In particular, how PKR triggers a cascade of events involving IKK phosphorylation of IkappaB and NF-kappaB nuclear translocation has been intensively studied. At the cellular and organism levels PKR exerts antiproliferative effects, and it is a key antiviral agent. A point of convergence in both effects is that PKR activation results in apoptosis induction. The extent and strength of the antiviral action of PKR are clearly understood by the findings that unrelated viral proteins of animal viruses have evolved to inhibit PKR action by using diverse strategies. The case for the pathological consequences of the antiproliferative action of PKR is less understood, but therapeutic strategies aimed at targeting PKR are beginning to offer promising results.

Composición corporal de cabras criollas neuquinas en distintas notas de condición corporal

Se evaluó la relación existente entre las notas de condición corporal (CC) y la composición corporal en 20 cabras adultas de la raza Criolla Neuquina. Previo al sacrificio se registró el peso y la condición corporal lumbar (CCL), condición corporal esternal (CCE) y condición corporal caudal (CCC). Luego del sacrificio y el desuello, se separaron la grasa omental y mesentérica, procediendo luego a separar la grasa pericárdica. Finalmente se pesaron por separado todos los componentes grasos extraídos. La canal se pesó fresca y a las 24 h, luego del oreo. Se separó la grasa de pélvico-renal (KKCF), luego se dividió la canal en dos mitades iguales con sierra eléctrica y se pesó la canal izquierda. Para finalizar se llevó a cabo la disección de la media canal izquierda en sus componentes grasa subcutánea, grasa intermuscular, hueso y magro. Los valores del presente trabajo confirman la deposición prematura de la grasa intermuscular y mesentérica y tardía de la KKCF, subcutánea y omental. La mayor correlación correspondió a la KKCF, confirmando la conveniencia de utilizar este parámetro en la estimación del grado de engrasamiento. La mejor correlación entre las distintas notas de CC y los depósitos grasos expresados como proporción del peso vivo prefaena se obtuvo entre CCL y grasa total.

Actividad sexual en cabritos criollos neuquinos de la Patagonia Argentina

El conocimiento sobre el inicio de la pubertad y la maduración sexual en una raza o biotipo de animal doméstico constituye una herramienta necesaria para realizar un correcto manejo reproductivo. Los machos caprinos de diferentes razas presentan variación en el inicio de su actividad reproductiva. En 33 cabritos Criollos de la provincia del Neuquén, manejados en condiciones extensivas de producción (Lat. 41o 02' S Long. 70o 34' O), durante los meses de abril a julio (180-270 días de edad) se determinó la ruptura de la membrana prepucial y la capacidad de copulación, mediante su permanencia durante 10 minutos con cuatro hembras caprinas inducidas en estro mediante tratamiento hormonal. Durante los meses de abril a julio las tasas mensuales de cabritos que presentaron ruptura de su membrana prepucial y capacidad de copulación fueron 69,6; 78,3; 78,3; 82,6% y 18,7; 50; 61,1; 63,1% respectivamente. Para este período, los pesos vivos y circunferencias testiculares medias mensuales fueron 17,3 ± 0,07; 19,7 ± 0,07; 19,2 ± 0,06; 17,8 ± 0,06 kg y 16,5 ± 0,08; 16,7 ± 0,08; 17,6 ± 0,08; 17,2 ± 0,07 cm, respectivamente. Se determinó mensualmente que los cabritos sin membrana prepucial presentaron valores medios significativamente mayores en su peso vivo y circunferencia testicular con respecto a los cabritos con membrana prepucial. Asimismo, los cabritos con capacidad copulatoria tuvieron valores medios significativamente mayores en peso vivo y circunferencia testicular con respecto a los cabritos sin capacidad copulatoria. Se concluye que los cabritos Criollos Neuquinos presentan una ruptura progresiva de su membrana prepucial y un incremento en su capacidad copulatoria durante su primera estación reproductiva. El desarrollo sexual se presenta como un proceso gradual y estaría considerablemente asociado al peso vivo y a la circunferencia testicular.

KRAS and BRAF oncogenic mutations in MSS colorectal carcinoma progression

In sporadic colorectal cancer (CRC), KRAS are alternative to BRAF mutations and occur, respectively, in 30 and 10% of cases. Few reports addressed the association between KRAS-BRAF mutations and tumour progression specifically in sporadic microsatellite-stable (MSS) CRC. We screened KRAS and BRAF in 250 MSS primary CRC and 45 lymph node (LN) metastases and analysed the pathological features of the cases to understand the involvement of KRAS-BRAF activation in progression and metastasis. Forty-five per cent of primary MSS CRCs carried mutations in at least one of these genes and mutations were associated with wall invasion (P=0.02), presence and number of LN metastases (P=0.02 and P=0.03, respectively), distant metastases (P=0.004) and advanced stage (P=0.01). We demonstrated that KRAS and BRAF are alternative events in Tis and T1 MSS CRC and, KRAS rather than BRAF mutations, contributed to the progression of MSS CRC. The frequency of KRAS and/or BRAF mutations was higher in LN metastases than in primary carcinomas (P=0.0002). Mutated LN metastases displayed KRAS associated or not with BRAF mutations. BRAF mutations were never present as a single event. Concomitant KRAS and BRAF mutations increased along progression of MSS CRCs, suggesting that activation of both genes is likely to harbour a synergistic effect.

Population dynamics of RNA viruses: the essential contribution of mutant spectra

Cells and their viral and cellular parasites are genetically highly diverse, and their genomes contain signs of past and present variation and mobility. The great adaptive potential of viruses, conferred on them by high mutation rates and quasispecies dynamics, demands new strategies for viral disease prevention and control. This necessitates a more detailed knowledge of viral population structure and dynamics. Here we review studies with the important animal pathogen Foot-and-mouth disease virus (FMDV) that document modulating effects of the mutant spectra that compose viral populations. As a consequence of interactions within mutant spectra, enhanced mutagenesis may lead to viral extinction, and this is currently investigated as a new antiviral strategy, termed virus entry into error catastrophe.

Atypical presentation of aortic dissection secondary to a gunshot wound

We present a case of aortic dissection secondary to a gunshot wound. The traumatic aortic dissection in this patient occurred secondary to the cavitary forces produced by the bullet passing through the patient's chest. This is a rare phenomenon that could easily be missed if attention is placed only on the more obvious injuries.

Viruses as quasispecies: biological implications

During viral infections, the complex and dynamic distributions of variants, termed viral quasispecies, play a key role in the adaptability of viruses to changing environments and the fate of the population as a whole. Mutant spectra are continuously and avoidably generated during RNA genome replication, and they are not just a by-product of error-prone replication, devoid of biological relevance. On the contrary, current evidence indicates that mutant spectra contribute to viral pathogenesis, can modulate the expression of phenotypic traits by subpopulations of viruses, can include memory genomes that reflect the past evolutionary history of the viral lineage, and, furthermore, can participate in viral extinction through lethal mutagenesis. Also, mutant spectra are the target on which selection and random drift act to shape the long-term evolution of viruses. The biological relevance of mutant spectra is the central topic of this chapter.

BRAF screening as a low-cost effective strategy for simplifying HNPCC genetic testing

BACKGROUND

According to the international criteria for hereditary non-polyposis colorectal cancer (HNPCC) diagnostics, cancer patients with a family history or early onset of colorectal tumours showing high microsatellite instability (MSI-H) should receive genetic counselling and be offered testing for germline mutations in DNA repair genes, mainly MLH1 and MSH2. Recently, an oncogenic V600E hotspot mutation within BRAF, a kinase encoding gene from the RAS/RAF/MAPK pathway, has been found to be associated with sporadic MSI-H colon cancer, but its association with HNPCC remains to be further clarified.

METHODS

BRAF-V600E mutations were analysed by automatic sequencing in colorectal cancers from 206 sporadic cases with MSI-H and 111 HNPCC cases with known germline mutations in MLH1 and MSH2. In addition, 45 HNPCC cases showing abnormal immunostaining for MSH2 were also analysed.

RESULTS

The BRAF-V600E hotspot mutation was found in 40% (82/206) of the sporadic MSI-H tumours analysed but in none of the 111 tested HNPCC tumours or in the 45 cases showing abnormal MSH2 immunostaining.

CONCLUSIONS

Detection of the V600E mutation in a colorectal MSI-H tumour argues against the presence of a germline mutation in either the MLH1 or MSH2 gene. Therefore, screening of these mismatch repair (MMR) genes can be avoided in cases positive for V600E if no other significant evidence, such as fulfilment of the strict Amsterdam criteria, suggests MMR associated HNPCC. In this context, mutation analysis of the BRAF hotspot is a reliable, fast, and low cost strategy which simplifies genetic testing for HNPCC.

Phenotypic differentiation of exterior traits in local Criollo Goat Population in Patagonia (Argentina)

Abstract. The Neuquén-Criollo goat is a significant genetic resource, adapted to the singular harsh environment of North Patagonia. Its present gene pool was built up from different breeds since the Spanish colonization being Angora the latest introduced. High phenotypic diversity and their geographical distribution suggest a subdivision of this goat population into four close sub-areas. As phenotypic characterization was carried out on 827 Criollo adult goats. Analyse were based on fourteen quantitative (morphostructural) and eight qualitative (morphological) variables. Correspondence analyses for qualitative and canonical discriminant analysis for quantitative traits were performed, using hair types as classification variable. Results were consistent in differentiating the four considered sub-areas. Neuquen Criollo breed could be characterized in two ecotypes: Short and Long hair goats, a mixed type area and a crossbred area fulfil the types distribution. Principal divergence factors would be isolation, natural and artificial selection, transhumance and exotic breeds introduction.

International and Italian prognostic indices in follicular lymphoma

BACKGROUND AND OBJECTIVES

The International Prognostic Index (IPI), initially designed for aggressive lymphomas, has been successfully used in patients with follicular lymphoma (FL). The Italian Lymphoma Intergroup (ILI) created a new prognostic index specific for FL. The aim of this study was to compare which of these two indices is more useful when applied to a large group of FL patients.

DESIGN AND METHODS

Both indices, IPI (age >60 years, extranodal involvement >=2 sites, elevated lactate dehydrogenase, ECOG >=2, stage >=3) and ILI (age >60 years, extranodal involvement >=2 sites, elevated lactate dehydrogenase, male sex, B symptoms, erythrocyte sedimentation rate >=30 mm 1(st) hour) were calculated in a group of 398 FL patients. Overall survival (OS) and progression-free survival (PFS) associated with each prognostic group were calculated according to the Kaplan-Meier method.

RESULTS

The overall concordance between both indices was 73%. According to the IPI 122 patients (31%) were in the higher risk group, whereas according to the ILI 132 (33%) were; concordance between the high risk groups was 66%. The 10-years OS and PFS rates after applying the IPI system were 73% and 37%, respectively, in the low risk groups; 47% and 26%, in the intermediate risk groups and 25% and 2%, in the high risk groups (log-rank=69.2 and 41.3, respectively; p<0.0001). According to ILI index the 10-year OS and PFS were 60% and 34%, respectively, in the low risk groups; 59% and 30%, in the intermediate risk groups and 17% and 0%, in the high risk groups (log-rank=86.6 and 58.5, respectively; p<0.0001).

INTERPRETATION AND CONCLUSIONS

Both the IPI and ILI index, are useful for classifying FL patients into different risk groups. Although it seems that the ILI index has a higher discriminating power among groups, significant differences were not observed in identifying FL patients with a poor outcome.

Intravascular ultrasound of the elastic pulmonary arteries: a new approach for the evaluation of primary pulmonary hypertension

OBJECTIVE

To assess the structural and functional characteristics of pulmonary arteries by intravascular ultrasound (IVUS) in the setting of primary pulmonary hypertension, and to correlate the ultrasound findings with haemodynamic variables and mortality at follow up.

DESIGN

Prospective observational study.

SETTING

University hospital (tertiary referral centre).

PATIENTS

20 consecutive patients with primary pulmonary hypertension (16 female; mean (SD) age, 39 (14) years).

METHODS

Cardiac catheterisation and simultaneous IVUS of pulmonary artery branches at baseline and after infusion of epoprostenol.

RESULTS

33 pulmonary arteries with a mean diameter of 3.91 (0.80) mm were imaged, and wall thickening was observed in all cases, 64% being eccentric. Mean wall thickness was 0.37 (0.13) mm, percentage wall area 31.0 (9.3)%, pulsatility 14.6 (4.8)%, and pulmonary/elastic strain index 449 (174) mm Hg. No correlation was observed between IVUS findings and haemodynamic variables. Epoprostenol infusion increased pulsatility by 53% and decreased the pulmonary/elastic strain index by 41% (p = 0.0001), irrespective of haemodynamic changes. At 18 (12) months follow up, nine patients had died. A reduced pulsatility and an increased pulmonary/elastic strain index were associated with increased mortality at follow up (12.0 (4.4)% v 16.4 (4.4)%, p = 0.03; 369 (67) v 546 (216) mm Hg, p = 0.02).

CONCLUSIONS

IVUS demonstrated pulmonary artery wall abnormalities in all patients with primary pulmonary hypertension, mostly eccentric. The severity of the changes did not correlate with haemodynamic variables, and epoprostenol improved pulmonary vessel stiffness. There was an association between impaired pulmonary artery functional state as determined by IVUS and mortality at follow up.

Molecular indetermination in the transition to error catastrophe: systematic elimination of lymphocytic choriomeningitis virus through mutagenesis does not correlate linearly with large increases in mutant spectrum complexity

Studies with several RNA viruses have shown that enhanced mutagenesis resulted in decreases of infectivity or virus extinction, as predicted from virus entry into error catastrophe. Here we report that lymphocytic choriomeningitis virus, the prototype arenavirus, is extremely susceptible to extinction mutagenesis by the base analog 5-fluorouracil. Virus elimination was preceded by increases in complexity of the mutant spectra of treated populations. However, careful molecular comparison of the mutant spectra of several genomic segments suggests that the largest increases in mutation frequency do not predict virus extinction. Highly mutated viral genomes have escaped detection presumably because lymphocytic choriomeningitis virus replicates at or near the error threshold, and genomes in the transition toward error catastrophe may have an extremely short half-life and escape detection with state-of-the-art cloning and sequencing technologies.

The need for continuous immunosuppression with cyclosporin A to maintain an experimental model of uveal melanoma

We investigated the need for continuous immunosuppression to maintain experimental tumours derived from human uveal melanoma cells implanted in the choroid of pigmented rabbits. Two groups of pigmented rabbits immunosuppressed with cyclosporin A (CsA) were implanted with human uveal melanoma cells in the suprachoroidal space. After 5 weeks, CsA was discontinued in group 2. Animals were treated with prophylactic antibiotics and examined weekly for tumour growth, weight and secondary effects; blood urea nitrogen levels were measured every two weeks. Autopsies and histopathological studies were performed after death or euthanasia at the end of week 12. The difference between the groups in the development of ophthalmoscopic tumours was not statistically significant 5 weeks after implantation. Tumours in group 1 grew progressively throughout the experiment, whereas group 2 tumours showed marked regression 3-4 weeks after discontinuing CsA. Tumours in group 1 were significantly larger and had greater mitotic activity and showed more ciliary body, optic nerve and extrascleral invasion than tumours in group 2, which showed massive fibrosis, minimal mitotic activity and marked inflammatory cell infiltration. Continuous immunosuppression with CsA seems to be necessary to maintain tumour growth in this experimental model of uveal melanoma.

Lack of association between methylenetetrahydrofolate reductase (MTHFR) C677T and ischaemic heart disease (IHD): family-based association study in a Spanish population

The effect of the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, traditionally associated with ischaemic heart disease (IHD), was assessed in a Spanish population. The transmission disequilibrium test (TDT) was used to determine a possible association in a sample of 101 trios of IHD patients. The distribution of MTHFR genotypes was similar in the IHD subjects and the parental group; the TT genotype was present in 14.9% of IHD patients, as compared to 15.2% in the parents. The frequency of the T allele was also similar in IHD cases and parents (39.6% vs. 42.4%; p = 0.649). The TDT confirmed that the observed transmission of the T allele did not deviate significantly from the expected one (chi2 = 0.743; p > 0.4). Our TDT analysis clearly demonstrates a lack of association between the T allele of the C677T mutation in MTHFR and cardiovascular artery disease, both for the general group and for different risk subgroups (smokers, hypertension, male sex, overweight and type A behaviour pattern) in the Spanish population.

Prevalence and genetic heterogeneity of the reverse transcriptase T69S-S-X insertion in pretreated HIV-infected patients

The emergence of resistance to antiretroviral drugs represents one of the main reasons for treatment failure in HIV-infected persons. Resistance to multiple nucleoside analogues may result from rearrangements in the HIV pol gene, in particular one insertion of two amino acids at position 69. Herein, we examined the prevalence of this resistant genotype and its genetic heterogeneity in a group of 475 healthy pretreated HIV-positive subjects in Spain. Only 4 (0.8%) carried the codon 69 insertion. It was always found coupled to the T69S mutation. The extra amino acids were S-S in 2 subjects and S-G in the other 2. The presence of the insert was seen only in subjects previously exposed to AZT monotherapy for at least 6 months.