Analysis of Presentation and Outcomes in Acute Limb Ischemia Patients During COVID-19 State of Emergency.

Background: During the COVID-19 pandemic, cardiovascular patients were found to be presenting to hospitals with myocardial infarctions and cerebrovascular accidents at progressed disease states. We noticed a parallel in acute limb ischemia (ALI) patients presenting during Massachusetts' COVID-19 State of Emergency declaration. We question whether patients developed a hesitancy to seek medical attention at hospitals due to fear of COVID-19.

Peak systolic velocity and color aliasing are important in the development of duplex ultrasound criteria for external carotid artery stenosis.

Objective: The external carotid artery (ECA) serves as a major collateral pathway for ophthalmic and cerebral artery blood supply. It is routinely examined as part of carotid duplex ultrasound, but criteria for determining ECA stenosis are poorly characterized and typically extrapolated from internal carotid artery data. This is despite the fact that the ECA is smaller in diameter, with a higher resistance and lower volume flow pattern.

Experienced operators achieve superior patency and wound complication rates with endoscopic great saphenous vein harvest compared with open harvest in lower extremity bypasses.

Objective: Prior studies have suggested improved wound complication rates but decreased primary patency in lower extremity bypasses performed with endoscopic vein harvest (EVH) vs open vein harvest (OVH). We hypothesize that the inferior patency reflects the initial learning curve for EVH and that improved patency can be achieved with experience.

Methods: This was a single-institution review of 113 patients with critical limb ischemia who underwent infrainguinal bypass with a continuous segment of great saphenous vein harvested endoscopically (n = 49) or through a single open incision (n = 64) from 2012 to 2017.

Blunt traumatic celiac artery avulsion managed with celiac artery ligation and open aorto-celiac bypass.

Traumatic celiac artery injuries are rare and highly lethal with reported mortality rates of 38-62%. The vast majority are caused by penetrating trauma with only 11 reported cases due to blunt trauma (Graham et al., 1978; Asensio et al.

Eversion Femoral Endarterectomy for Iliofemoral Occlusive Disease: A Description of Technique and Series of Cases.

Background: Eversion endarterectomy (EE) is a well-described technique for the treatment of extracranial cerebrovascular disease. Longitudinal arteriotomy and closure with patch angioplasty is the standard for infrainguinal arterial occlusive disease in the iliofemoral segment. A potential drawback of this technique is the introduction of exogenous material into the field.

Creation of the whole human genome microarray.

Several companies have recently announced the availability of products that enable a scientist to probe gene expression from the entire human genome on a single DNA microarray. This review will focus on the underlying technological trends that have made this achievement possible, the particular methodologies which are employed to create such microarrays and the implications of the whole human genome microarray for future biological studies. The single genome array represents an important milestone on the path to unraveling the complexity of the cellular networks that control living processes.

Characterization of 12 microsatellite loci of the human MHC in a panel of reference cell lines.

The human genome contains a large number of interspersed microsatellite repeats which exhibit a high degree of polymorphism and are inherited in a Mendelian fashion, making them extremely useful genetic markers. Several microsatellites have been described in the HLA region, but allele nomenclature, a set of broadly distributed controls, and typing methods have not been standardized, which has resulted in discrepant microsatellite data between laboratories. In this report we present a detailed protocol for genotyping microsatellites using a semi-automated fluorescence-based method.

A generic sequencing based typing approach for the identification of HLA-A diversity.

Sequencing Based Typing (SBT) is a generic approach for the identification of HLA-A polymorphism. This approach includes the high resolution typing of the HLA-A broad reacting groups, HLA-A subtypes and will identify new alleles directly. The SBT approach described here uses a locus specific amplification of DNA from exon 1 to exon 5.

Heterozygote and mutation detection by direct automated fluorescent DNA sequencing using a mutant Taq DNA polymerase.

We describe a method for direct cycle sequencing of PCR fragments amplified from genomic DNA or cDNA. DNA sequencing template is amplified using PCR and oligonucleotide primers flanking the region of interest. The amplified fragment is directly cycle sequenced using fluorescent sequencing primers, Sanger dideoxy sequencing chemistry and an enzyme mixture of a mutant Taq DNA polymerase and thermostable pyrophosphatase.

Efficient, automatic detection of heterozygous bases during large-scale DNA sequence screening.

A crucial factor in the success of positional cloning efforts is the ability to screen rapidly many different candidate genes for mutations. By modifying standard software, we have improved the detection of heterozygous base positions in PCR products sequenced by cycle sequencing. A key element of the method is the incorporation of a modified heterozygote detection algorithm that permits the use of DNA sequence data derived from PCR and sequencing reactions that have not been fully optimized.

An evaluation of a multicenter study on HLA-DPB1 typing using solid-phase Taq-cycle sequencing chemistry.

In HLA Class II genes, polymorphism is mainly located in the second exon. Most DNA based typing methods are confined to the identification of specific sequence motifs in the second exon. In contrast, Sequencing Based Typing (SBT) elucidates the entire exon 2 sequence for typing.

Quantitative detection of HIV-1 drug resistance mutations by automated DNA sequencing.

A comparison has been made between manual and automated DNA sequencing procedures to evaluate the ability to distinguish mixtures of wild-type and mutant sequences. Quantitative detection of such mixtures of HIV-1 drug resistance mutations was best achieved using an automated system that uses fluorescent-labelled sequencing primers. This procedure has a wide range of applications in clinical research, including heterozygote analysis.

Alternative labeling techniques for automated fluorescence based analysis of PCR products.

We present here convenient and simple methods that utilize two new fluorescent tags, TOTO-1 and fluorescein-12-dUTP, in conjunction with analysis of PCR products on automated, fluorescence-based electrophoretic instruments. These methods should prove valuable in those applications wherein the effort or expense of covalently attaching a fluorescent tag onto one or both of the PCR primers is not justified. Advantages and disadvantages of the new labeling methods are then reviewed.

Fluorescent approaches to diagnosis of Lesch-Nyhan syndrome and quantitative analysis of carrier status.

Lesch-Nyhan syndrome is an X-linked recessive disorder caused by molecular defects within the HPRT gene. Deletional forms of this syndrome, most of which are inherited, account for 15% of the cases. In addition, a large percentage of cases are due to de novo point mutations.

Application of automated DNA sizing technology for genotyping microsatellite loci.

Highly polymorphic microsatellite loci offer great promise for gene mapping studies, but fulfillment of this potential will require substantial improvements in methods for accurate and efficient genotyping. Here, we report a genotyping method based on fluorescently labeled PCR primers and size characterization of PCR products using an automated DNA fragment analyzer. We capitalize on the availability of three distinct fluorescent dyes to label uniquely loci that overlap in size, and this innovation increases by threefold the number of loci that can be analyzed simultaneously.

The use of fluorescence detection and internal lane standards to size PCR products automatically.

We have developed chemical procedures, optical and electrophoretic instrumentation and computer software automate the analysis of polymerase chain reaction (PCR) products. DNA molecules labeled with up to four different fluorescent dyes are analyzed within a single electrophoresis gel lane. A size calibration curve is created for each electrophoresis lane from the electrophoretogram of uniquely labeled DNA fragments belonging to an internal lane standard that co-electrophoreses with the PCR products.

Automated genetic analysis.

Automation of several new, non-traditional techniques for genetic analysis has now become possible. A new system is described that performs gel electrophoretic analysis of DNA including VNTRs, gene segments, and restriction enzyme digests. The instrument detects emitted fluorescence from labeled DNA segments in real-time as they electrophore through a gel matrix past a scanning laser beam.

Genetic typing using automated electrophoresis and fluorescence detection.

Multi-color fluorescence detection systems offer unique advantages when compared to single label detection methods for DNA typing, genetic disease testing, population fingerprinting, and DNA mapping. Internal controls are easily used and identified by different color dye labels. Multiple independent samples or multiple analyses of the same sample are run in each lane of a gel.

Automated DNA sequencing methods involving polymerase chain reaction.

Polymerase chain reaction (PCR) as a method for preparing DNA templates has been used for several DNA sequencing applications. An in situ procedure for directly sequencing PCR products by the dideoxy-termination method has been developed by using fluorophore-labeled sequencing primers. Completed sequence reactions were combined and loaded into a single electrophoretic lane of a fluorescence-based DNA sequence analyzer.

Immunoassay techniques with fluorescent phycobiliprotein conjugates.

We describe immunoassay techniques that take advantage of the novel properties of phycobiliprotein fluorescent dyes. These dyes, which can be isolated from a wide variety of algae, exhibit extremely high absorptivities, high quantum efficiencies, and excitation and emission bands across the visible spectrum. These stable, hydrophilic proteins can easily be linked to antibodies by conventional protein cross-linking reagents.

A new immunoassay based on fluorescence excitation by internal reflection spectroscopy.

A new immunoassay technique is described which uses totally internally reflected light to excite the fluorescence of fluorescein labeled antibody which has become bound to a hapten--protein conjugate absorbed on a quartz-plate in the antibody solution. The presence of any free hapten in solution reduces the amount of antibody free to bind to the surface and thus reduces the fluorescence signal. Measurement of the decrease of the fluorescent signal then gives a measure of the concentration of free hapten present.