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Biomedical subjects

Mark Hall

Publications and source records attributed to Mark Hall.

9 recordsLinked to original sources
PubMed2026

The co-existence of Ehlers-Danlos syndrome and postural orthostatic tachycardia syndrome: A systematic review of the literature.

There is a growing body of literature evaluating both postural orthostatic tachycardia syndrome (POTS) and Ehlers-Danlos syndrome (EDS). We conducted a systematic review to evaluate what is currently known about the co-existence of both conditions. A search of MEDLINE and EMBASE was performed in December 2025 and data were collected in tables and pooled to determine the prevalence of POTS in EDS and EDS in POTS. A total of 30 studies were included with 8421 patients with EDS and 12,983 patients with POTS. The average age across 16 studies that reported mean age was 33.3 years. POTS in patients with EDS ranges from 17.5% to 92.7% depending on the population. EDS in patients with POTS ranges from 17.9% to 50.0% depending on the population. One study suggested that patients with EDS and POTS had greater medication use, pain medications and greater number of clinic visits compared to POTS alone while another suggests that these patients have greater gastrointestinal symptoms and the odds were greatest for postprandial distress syndrome, chronic nausea and vomiting syndrome, vomiting and post-prandial fullness. We conclude that EDS and POTS frequently co-occur, and proportions of patients with POTS and EDS depends on the population evaluated. Overall, more research is needed to better understand how to effectively manage patients living with both EDS and POTS.

Humans↗
PubMed2005

Molecular identification of a novel deltaproteobacterium as the etiologic agent of epizootic bovine abortion (foothill abortion).

Epizootic bovine abortion (EBA) is endemic in California's coastal range and the foothill regions of the Sierra Nevada, where it has been the primary diagnosed cause of abortion in beef cattle for >50 years. Investigation of these losses has defined a specific fetal syndrome characterized by late-term abortion or birth of weak or dead calves. Although the unusual clinical presentation and unique fetal pathology associated with EBA have been recognized since the 1950s, the identity of the etiologic agent is unknown. In this study, suppression-hybridization PCR was used to identify a fragment of the 16S rRNA gene of a previously undescribed bacterium in thymus tissue derived from affected fetuses. Phylogenetic analysis revealed that this pathogen was a deltaproteobacterium closely related to members of the order Myxococcales. A specific PCR was subsequently developed to detect the presence of this bacterium in DNA extracted from fetal thymuses. Using histopathology as the definitive diagnosis for EBA, this PCR demonstrated 100% specificity and 88% sensitivity. The bacterium was also detected in the argasid tick Ornithodoros coriaceus, which is the recognized vector of EBA. These data imply a close association between this novel agent and the etiology of EBA.

Abortion, Veterinary↗
PubMed2004

The role of p22 NF-E4 in human globin gene switching.

The human stage selector protein, a complex containing the ubiquitous transcription factor CP2 and the erythroid-specific factor p22 NF-E4, facilitates the interaction of the gamma-globin genes with the locus control region in fetal erythroid cells. Enforced expression of p22 NF-E4 in K562 cells and human cord blood progenitors increases fetal globin gene expression, and in progenitors, reduces beta-globin expression. To examine the role of NF-E4 in an in vivo model of hemoglobin switching, we enforced the expression of p22 NF-E4 in transgenic mice carrying the human beta-globin locus yeast artificial chromosome. Although murine erythropoiesis and globin gene expression is unaffected in these mice, the expression profile of the human globin genes is altered. All three transgenic lines displayed an increased gamma:beta-globin ratio in E12.5-14.5 fetal liver, resulting in a delay in the fetal/adult switch. At E12.5, this is primarily due to a reduction of beta-gene expression, whereas at E14.5, the increased gamma:beta ratio is due to enhanced gamma-gene expression. Despite this, the switch in globin subtype is fully completed in the adult bone marrow. These findings indicate that p22 NF-E4 is capable of influencing human globin gene expression in vivo but is incapable of overriding the intrinsic mechanisms governing gamma-gene silencing in this context.

Animals↗
PubMed2004

Data mining in bioinformatics using Weka.

UNLABELLED: The Weka machine learning workbench provides a general-purpose environment for automatic classification, regression, clustering and feature selection-common data mining problems in bioinformatics research. It contains an extensive collection of machine learning algorithms and data pre-processing methods complemented by graphical user interfaces for data exploration and the experimental comparison of different machine learning techniques on the same problem. Weka can process data given in the form of a single relational table. Its main objectives are to (a) assist users in extracting useful information from data and (b) enable them to easily identify a suitable algorithm for generating an accurate predictive model from it. AVAILABILITY: http://www.cs.waikato.ac.nz/ml/weka.

Algorithms↗
PubMed2004

Screening in liver disease: report of an AASLD clinical workshop.

This report summarizes an AASLD Clinical Workshop that was presented at Digestive Diseases Week 2003 on screening in liver diseases. As newer diagnostic tests become available, many liver diseases and complications of liver disease can be detected at an early asymptomatic stage. In many cases, early detection can lead to earlier treatment and an improved outcome. However, screening for liver diseases in asymptomatic persons has the potential for adverse consequences, including discrimination and stigmatization. The cost of screening programs is significant, and access to screening tests varies in different countries. Future screening programs require careful planning and implementation to balance the benefits, risks, and cost-effectiveness. This review outlines the concepts of screening and their application to a broad range of liver diseases.

Cost-Benefit Analysis↗
PubMed2003

Inositol- and folate-resistant neural tube defects in mice lacking the epithelial-specific factor Grhl-3.

The neural tube defects (NTDs) spina bifida and anencephaly are widely prevalent severe birth defects. The mouse mutant curly tail (ct/ct) has served as a model of NTDs for 50 years, even though the responsible genetic defect remained unrecognized. Here we show by gene targeting, mapping and genetic complementation studies that a mouse homolog of the Drosophila grainyhead (grh) gene, grainyhead-like-3 (Grhl3), is a compelling candidate for the gene underlying the curly tail phenotype. The NTDs in Grhl3-null mice are more severe than those in the curly tail strain, as the Grhl3 alleles in ct/ct mice are hypomorphic. Spina bifida in ct/ct mice is folate resistant, but its incidence can be markedly reduced by maternal inositol supplementation periconceptually. The NTDs in Grhl3-/- embryos are also folate resistant, but unlike those in ct/ct mice, they are resistant to inositol. These findings suggest that residual Grhl3 expression in ct/ct mice may be required for inositol rescue of folate-resistant NTDs.

Animals↗
PubMed2001

Microvascular thrombosis in pediatric multiple organ failure: Is it a therapeutic target?

PURPOSE: To discuss the current rationale for the use of specific and nonspecific therapies for thrombotic microangiopathy in thrombocytopenia-associated pediatric multiple organ failure syndromes. Methods: Pertinent PubMed and MEDLINE citations and proceedings of recent critical care meeting presentations were reviewed. RESULTS: Critical care clinicians have reported using antithrombin III concentrate, protein C concentrate, activated protein C, prostacyclin and its analogues, heparin, tissue factor pathway inhibitor concentrate, plasma infusion, plasma exchange, whole blood exchange, pentoxifylline, tissue plasminogen activator, urokinase, and streptokinase with perceived therapeutic benefits in patients with thrombocytopenia-associated multiple organ failure, including those with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, disseminated intravascular coagulation syndrome, and secondary thrombotic microangiopathy syndrome without prolonged prothrombin time/activated partial thromboplastin time. CONCLUSION: Assuming that underlying disease is remediable, a consensus has developed that thrombotic microangiopathy is a therapeutic target in children with thrombocytopenia-associated multiple organ failure syndromes. Studies are warranted to delineate efficacious use of specific and nonspecific therapies to prevent and reverse thrombotic microangiopathy in these patients.

Journal Article↗