Cerebral protection during open retrograde angioplasty/stenting of common carotid and innominate artery stenoses.

BACKGROUND: This was a retrospective study of the effectiveness of open, retrograde angioplasty/stenting of supra-aortic arterial stenoses combined with transcranial Doppler-directed dextran therapy in preventing perioperative embolization. METHODS: Eight patients underwent angioplasty/stenting of the proximal common carotid (synchronous carotid endarterectomy (CEA) in six), while four underwent angioplasty/stenting of the innominate artery (synchronous CEA in one). Open exposure of the carotid bifurcation enabled temporary carotid clamping to protect the brain from procedural embolization. Dextran was administered to patients with a high rate of embolization on transcranial Doppler after the operation. RESULTS: No emboli were recorded in the cerebral circulation during the actual angioplasty procedure when the internal carotid artery was clamped. After operation three patients developed high-rate embolization and received dextran. No strokes or deaths occurred within 30 days of treatment. One patient developed symptoms and a recurrent stenosis greater than 50 per cent during follow-up and was treated by redo angioplasty. CONCLUSION: Retrograde angioplasty/stenting with or without synchronous CEA offers an alternative approach to treating patients with supra-aortic inflow disease.

Detection of HCV in bile duct epithelium by laser capture microdissection (LCM).

Chronic hepatitis C affects 0.3 to 1.5% of the general population worldwide. The estimated total number of newly acquired hepatitis C virus (HCV) infections is 28,000 in the USA, with 10,000 deaths each year resulting from HCV-associated chronic liver disease. Histological examination of liver tissue from chronic HCV infection shows lymphoid aggregates or follicles in the portal triads, focal fatty change and lobular inflammation. Hepatitis-associated bile duct lesion (HBL) is seen in 5 - 91% of the cases. While the morphological spectrum of HBL has been well described, its pathogenesis in hepatitis C is not known. To this date, evidence supports both the direct injury and immune-mediated mechanisms, but to what extent these mechanisms are involved in the pathogenesis of HBL in chronic hepatitis C remains unclear. Our study showed the presence of HCV in the bile duct epithelium of patients with chronic hepatitis C infection, using the laser capture microdissection technique. These results will enhance our diagnostic capabilities and treatment of chronic hepatitis C infection.

A Bayesian framework for SNP identification.

As evolutionary models for single-nucleotide polymorphisms (SNPs) become available, methods for using them in the context of evolutionary information and expert prior information is a necessity. We formulate a probability model for SNPs as a Bayesian inference problem. Using this framework we compare the individual and combined predictive ability of four evolutionary models of varying levels of specificity on three SNP databases (two specifically targeted at functional SNPs) by calculating posterior probabilities and generating Receiver Operating Characteristic (ROC) curves. We discover that none of the models do exceptionally well, in some cases no better than a random-guess model. However, we demonstrate that several properties of the Bayesian formulation improve the predictability of SNPs in the three databases, specifically the ability to utilize mixtures of evolutionary models and a prior based on the genetic code.

The excess of strokes in female patients after CEA is due to their increased thromboembolic potential--analysis of 775 cases.

INTRODUCTION: Women suffer an excess of complications following arterial surgery, including an increased stroke risk following CEA. In order to investigate this further we studied men and women's thromboembolic potential following CEA. METHOD: Analysis of prospectively collected data on 775 consecutive CEAs performed between October 1995 and October 2001, to identify the number of microembolic events detected following CEA. RESULTS: Overall women had a 2.2 fold increase in the number of postoperative emboli detected (95% CI 1.2-3.3). Of those patients with significant numbers of postoperative emboli (>25), 68% were female against 22% for men (p=0.009). In order to prevent progression onto postoperative thrombotic stroke 9.7% of women were treated with intravenous Dextran-40 therapy, as opposed to only 2.7% of men (p=0.013). There were no significant differences between men and women's preoperative risk factors and/or factors relating to their operation. CONCLUSION: It is possible that women's excess of postoperative complications following arterial surgery is related to their apparent increased thromboembolic potential following acute arterial injury.

Combined therapy with clopidogrel and aspirin significantly increases the bleeding time through a synergistic antiplatelet action.

OBJECTIVE: Many thromboembolic events occur in patients taking aspirin. Dual therapy with aspirin and clopidogrel may prove effective at reduction of thromboembolic complications. However, the extent to which these two drugs interact may significantly increase the risk of bleeding in open surgery. Because of the increased use of combination antiplatelet therapy in populations with significant atherosclerotic disease, this risk needs to be evaluated by the assessment of the combined effect in vivo of clopidogrel and aspirin on bleeding time and platelet function. OUTCOMES: In seven healthy subjects, addition of low dose clopidogrel (2 x 75 mg) to aspirin (150 mg) therapy significantly increased bleeding time (from 7.6 +/- 3.4 minutes to 17.5 +/- 8.6 minutes; P <.05), with concomitant falls in adenosine diphosphate (ADP)-induced platelet fibrinogen binding and aggregation (P <.05). Increasing the dose of clopidogrel to 300 mg increased bleeding time (to 24.9 +/- 8.5 minutes; P <.05) without significant additional platelet inhibition. There was considerable variability in the individual subject platelet response to the lower dose of clopidogrel. Those patients with the highest ADP response at baseline had the least response, and subjects with a weak response to ADP at baseline achieved maximal platelet inhibition with the low dose of clopidogrel. CONCLUSION: The increases in bleeding times should be considered in combination antiplatelet therapy in patients who undergo open vascular surgery.

Molecular diagnosis of skin-associated infectious agents.

Molecular pathology is a relatively new division of laboratory medicine that detects, characterizes, and/or quantifies nucleic acids to assist in the diagnosis of human disease. Molecular assays augment classic areas of laboratory medicine by providing additional diagnostic data more quickly or by providing results that are not obtainable using standard methods. For these reasons, molecular pathology is the most rapidly growing area in laboratory medicine.

Prevalence of herpesviruses in cranial nerve ganglia.

A number of cranial nerve disorders are known to result from viral infection or reactivation, including Bell's palsy, Ramsay Hunt syndrome and herpetic laryngitis. The consequences of these diseases are well established although the patient population at risk is not. Prevalence studies in the general population are an initial step toward defining individuals at risk. The aim of this study was to determine the prevalence of herpesvirus DNA in cranial nerve ganglia in a random population sample. Qualitative molecular biologic analysis using polymerase chain reaction assay of the trigeminal, geniculate, vestibular, spiral and vagal ganglia was used in 18 randomly selected fresh cadaver heads. Herpes simplex virus (HSV) DNA was detected in 42% of all ganglia surveyed. Varicella zoster virus (VZV) DNA was detected in 44% of all ganglia. The difference in the prevalence rate between viruses was not significant (p = 0.63). At least 1 of the 2 viruses was found in 65% of all ganglia. Both HSV and VZV can commonly be recovered from cranial nerve ganglia. In order to confirm a viral etiology for various cranial nerve disorders, demonstration of a significant difference in prevalence of the viruses in specimens from afflicted individuals will be necessary.

MTHFR 677 C-->T mutation: a predictor of early-onset coronary artery disease risk.

The atherosclerotic potential of the methyenetetrahydrofolate reductase (MTHFR) gene mutation 677 C --> T substitution remains controversial. In this study, we describe the association of this mutation in a Southern Texan patient population of multiracial ethnic background with risk and extent of coronary artery disease (CAD) as measured by luminal narrowing. Sixty nine patients who were 50 years or younger composed our population. Chi-square analysis was used to analyze the data and found a significant association between CAD and this mutation (P value=0.03). In addition, in the small number of patients in this study who had diabetes, those who had mutation have more severe disease than those without the mutation. This study highlights the potential cardiovascular prognostic significance of the MTHFR 677 C --> T in the studied population.

T-gamma gene rearrangement and CMV mononucleosis.

A clonal T-gamma rearrangement was found in peripheral blood and bone marrow in a 57-year-old female who presented with 6-week history of fevers, night sweats, and weight loss. Splenomegaly, hemolytic anemia, atypical lymphocytosis, a marrow lymphoid aggregate, and elevated LDH had suggested lymphoproliferative disease. However, IgM serology for cytomegalovirus (CMV) was positive. With observation alone, her clinical features improved over 4 weeks with normalization of the blood count and disappearance of CMV viremia and the aberrant T-gamma clone. Acute CMV infection may mimic lymphoproliferative disease. T-gamma gene rearrangement may be part of the immune response to CMV infection and is not specific to lymphoid neoplasia.

Schizophrenia and schizophrenia-spectrum personality disorders in the first-degree relatives of children with schizophrenia: the UCLA family study.

BACKGROUND: This study tested the hypothesis that childhood-onset schizophrenia (COS) is a variant of adult-onset schizophrenia (AOS) by determining if first-degree relatives of COS probands have an increased risk for schizophrenia and schizotypal and paranoid personality disorders. METHODS: Relatives of COS probands (n = 148) were compared with relatives of attention-deficit/hyperactivity disorder (ADHD) (n = 368) and community control (n = 206) probands. Age-appropriate structured diagnostic interviews were used to assign DSM-III-R diagnoses to probands and their relatives. Family psychiatric history was elicited from multiple informants. Diagnoses of relatives were made blind to information about probands' diagnoses. Final consensus diagnoses, which integrated family history, direct interview information, and medical records, are reported in this article. RESULTS: There was an increased lifetime morbid risk for schizophrenia (4.95% +/- 2.16%) and schizotypal personality disorder (4.20% +/- 2.06%) in the parents of COS probands compared with parents of ADHD (0.45% +/- 0.45%, 0.91% +/- 0.63%) and community control (0%) probands. The parents of COS probands diagnosed as having schizophrenia had an early age of first onset of schizophrenia. Risk for avoidant personality disorder (9.41% +/- 3.17%) was increased in the parents of COS probands compared with parents of community controls (1.67% +/- 1.17%). CONCLUSIONS: The psychiatric disorders that do and do not aggregate in the parents of COS probands are remarkably similar to the disorders that do and do not aggregate in the parents of adults with schizophrenia in modern family studies. These findings provide compelling support for the hypothesis of etiological continuity between COS and AOS.

Effects of storage and viral load on hepatitis C viral genotyping.

Hepatitis C virus (HCV) genotyping is important for determining the treatment protocol for hepatitis C patients. Since amplified material from the Roche HCV Monitor kit is compatible with the Innogenetics INNO-LiPA HCV II kit (line probe assay), amplicons from the Monitor assay can be used to identify the HCV genotype. The Monitor package insert recommends using amplicons within a 7-day period (at 4 degrees C) following amplification. It was hypothesized that storage of amplicons for 4 weeks and longer (at -20 degrees C) would not affect the sensitivity of the genotyping assay. After denaturation, amplicons from two genotypes were stored for 7-386 days prior to performing the genotyping assay. Storage of amplicons did not hamper the ability to identify the genotype. Additionally, the sensitivity of the assay was evaluated by analyzing five genotypes with low viral loads. HCV genotypes were detected most consistently at viral levels of 10,000 copies/mL. In conclusion, the Innogenetics genotyping assay can use stored amplicons, thus reducing the cost of the assay by avoiding additional PCR reactions. Determining the sensitivity of this assay facilitates the efficient use of this test by incorporating a sensitivity cutoff of >or=10,000 copies/mL.

CD13-positive anaplastic large cell lymphoma of T-cell origin--a diagnostic and histogenetic problem.

The expression of myelomonocytic-associated antigens in anaplastic large cell lymphomas (ALCLs), particularly those presenting in extranodal sites, can make their distinction from extramedullary myeloid cell tumors (EMCTs) or histiocytic tumors problematic. Yet, this distinction is clinically significant because of its therapeutic and prognostic implications. Herein, we describe a case of extranodal anaplastic lymphoma kinase-positive CD30-positive ALCL of T-cell origin in a 12-year-old boy, which was initially called an EMCT because of the expression of CD13 and HLA-DR detected by flow cytometry and the absence of other T-cell-related surface markers. However, the detection of cytoplasmic CD3 by flow cytometry prompted further studies. The tumor was composed of large cells with abundant slightly eosinophilic vacuolated cytoplasm and ovoid or reniform nuclei with a few small nucleoli. Using immunohistochemistry, the tumor was positive for CD45, CD30, CD45RO, and CD43 with a strong cytoplasmic and nuclear anaplastic lymphoma kinase stain. The tumor cells showed a T-cell clonal genotype. Electron microscopy revealed no ultrastructural features of myelomonocytic or histiocytic origin. The patient responded well to the chemotherapy and was in complete remission for 10 months at the time of submission of this manuscript. Review of the literature showed inconsistencies regarding the diagnosis, nomenclature, and, therefore, treatment and prognosis of these tumors. In addition, the CD13 expression in ALCL raises some histogenetic questions and may indicate origin from a pluripotent stem cell, misprogramming during malignant transformation, or a microenvironmental effect on lymphoid cell expression of surface antigens. Therefore, ALCL should be considered in the differential diagnosis of EMCTs or histiocytic tumors, particularly when surface marker lineage assignment is ambiguous.

Quantitative direct probe method for the detection of parvovirus B19.

Parvovirus B19 infection is associated with anemia and spontaneous abortions. While many qualitative assays are available, a few molecular-based quantitative methods have been described. This study reports the development and optimization of a quantitative direct-probe method for the detection of Parvovirus B19 DNA. Different concentrations of RNA probes were used to identify the optimal conditions for hybridizing to the target DNA. Detection of DNA was linear between concentrations of 2 ng/ml to 200 pg/ml. Because this method requires no enzymatic amplification, it is not susceptible to amplifier contamination or enzymatic inhibitors, and it can be applied to serum samples or paraffin-embedded tissue.

Incidence of Epstein-Barr virus in astronaut saliva during spaceflight.

BACKGROUND: Astronauts experience psychological and physical stresses that may result in reactivation of latent viruses during space-flight, potentially increasing the risk of disease among crewmembers. HYPOTHESIS: The shedding of Epstein-Barr virus (EBV) in the saliva of astronauts will increase during spaceflight. METHODS: A total of 534 saliva specimens were collected from 11 EBV-seropositive astronauts before, during, and after four space shuttle missions. The presence of EBV DNA in saliva, assessed by polymerase chain reaction (PCR), was used to determine shedding patterns before, during, and after space-flight. RESULTS: EBV DNA was detected more frequently before flight than during (p < 0.001) or after (p < 0.01) flight. No significant difference between the inflight and postflight periods was detected in the frequency of occurrence of EBV DNA. CONCLUSIONS: The increased frequency of shedding of EBV before flight suggests that stress levels may be greater before launch than during or after spaceflight.

Thrombin peptide, TP508, induces differential gene expression in fibroblasts through a nonproteolytic activation pathway.

Prior studies have shown that synthetic peptides representing the domain of thrombin responsible for high-affinity binding to fibroblasts stimulate chemotactic and cell proliferative signals through a nonproteolytic mechanism. One of these peptides, TP508, has recently been shown to be chemotactic for neutrophils, to enhance collagen accumulation in wounds, to enhance revascularization of wounds, and to accelerate the healing of incisional and open wounds in normal animals and in animals with impaired healing. To determine whether TP508 activates the proteolytically activated receptor for thrombin (PAR1), or the signals that are activated by PAR1, we treated human fibroblasts with TP508 and the PAR1-activating peptide, SFLLRNP, and analyzed the effects of these peptides on gene expression using differential display reverse transcriptase polymerase chain reaction. TP508 induces expression of a number of specific message fragments with short tyrosine kinase-like domains that are not induced by SFLLRNP. Sequencing full-length clones prepared by Marathon extension of TP508-induced fragments revealed that among the induced transcripts, there was a sequence with 88% homology to human annexin V. Northern analysis with authentic annexin V cDNA confirms that TP508, but not SFLLRNP, induces expression of annexin V in human fibroblasts. These results demonstrate that TP508 activates a cellular response separate from that activated through PAR1 and supports the hypothesis that TP508 acts through a separate nonproteolytically activated thrombin receptor that may be responsible for high-affinity thrombin binding and for nonproteolytic signals that are required for thrombin stimulation of cell proliferation.

Inhibitors present in blood do not inhibit PCR from buccal cell preparations: case report.

BACKGROUND: Hemochromatosis is a common disease that is characterized by high ferritin levels and/or high iron saturation and mutations in two alleles. MATERIAL AND METHODS: Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) is often performed on DNA extracted from blood since blood yields high concentrations of DNA. However, inhibitors can cause PCR failure in DNA extracted from blood thus preventing a molecular diagnosis. RESULTS: This report describes a case where multiple blood draws resulted in unamplifiable DNA. Subsequently, a buccal cell sample was collected and extracted. DNA extracted from the buccal cells yielded amplifiable DNA in contrast to DNA extracted from the patient's blood. In addition, the patient was identified as having a homozygous mutation for one allele of the hemochromatosis gene. CONCLUSION: These results suggests that a buccal cell DNA extraction may be useful in cases where blood samples contain inhibitory substances for PCR.