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Biomedical subjects

J Hudson

Publications and source records attributed to J Hudson.

106 records · Page 6Linked to original sources
PubMed1975

Interaction of partially purified simian virus 40 T antigen with circular viral DNA molecules.

Mixing chromatographic fractions containing simian virus 40 (SV40) T antigen with SV40 [3H]-DNA I (double-stranded, circular, supercoiled) results in the conversion of the nucleic acid to a form that will bind to a nitrocellulose filter. Unlabeled SV40 DNA I successfully competes with this reaction. Under the conditions employed, the antigen-containing fractions bind a variety of circular, viral DNA molecules. Chromatography of the antigen in three systems reveals that the T immunoreactivity migrates with DNA binding activity. In a kinetic heat inactivation experiment, the antigenic reactivity disappears simultaneously with the DNA binding activity. The data indicate the presence of a discernible DNA binding activity in fractions containing T antigen and suggest that the T antigen is the DNA binding protein being measured.

Antigen-Antibody Reactions↗
PubMed1974

Characterization of a new murine cellular DNA polymerase.

A new DNA polymerase (peak A) has been identified in the high-speed pellet fraction of two subclones of nonvirus producing Balb/3T3 cells. The activity is associated with a molecule of approximately 70,000 molecular weight and chromatographs in two systems like the mouse type-C viral reverse transcriptase and a similar enzyme from the high-speed pellet fraction of a virus producing Balb/3T3 subclone, S(2)Cl(3). Comparable quantities of peak A are present in both nonvirus infected (A31) and mouse sarcoma virus transformed nonproducer (KA31) subclones. Virus producing cells contain 10-20 times more peak A polymerase activity. A31 and KA31 peak A are comparably inhibited by anti-mouse type C virus reverse transcriptase IgG but to a lesser degree than S(2)Cl(3) peak A or authentic viral reverse transcriptase. They can also be differentiated from the latter two enzymes by template preference studies. KA31 peak A can be distinguished from three other KA31 DNA polymerases (R-DNA polymerase and DNA polymerase N and C), and thus appears to be a new species of cellular DNA polymerase.

Adenine Nucleotides↗
PubMed1970

A study on the transcription of the polyoma viral genome.

The transcription of polyoma (Py) viral RNA was studied in primary mouse kidney cell cultures (a) during normal, asynchronous infection, (b) under conditions where Py-induced DNA synthesis was inhibited with 5-fluorodeoxyuridine, and (c) after the synchronized onset of Py-induced DNA synthesis. The results obtained suggest that the bulk of Py RNA transcribed after the (asynchronous or synchronized) onset of Py-induced DNA synthesis, designated as "late" Py RNA, corresponds to the polycistronic transcript of most or all of the genetic information contained in a strand of circular Py DNA. The rate at which late Py RNA is transcribed is related to the amount of free Py DNA present in the cultures. Py-infected cultures contain a second, minor component of Py RNA (of one or possibly more species), designated as "early" Py RNA. At least some of this RNA continues to be transcribed if Py-induced DNA synthesis is inhibited with 5-fluorodeoxyuridine and, possibly, also late during normal infection.

Centrifugation, Density Gradient↗
PubMedDate not supplied

Prospective controlled study of carotid endarterectomy with hemashield patch: is it thrombogenic?

The use of patch angioplasty after carotid endarterectomy (CEA) has been shown to have superior results to CEA with primary closure. Polytetrafluoroethylene (PTFE) patches have been shown to have comparable results to autogenous vein patching; however, PTFE has the disadvantage of prolonged hemostasis time. Therefore, many surgeons are using collagen-impregnated Dacron patches (Hemashield[HP]). We believe this is the first prospective controlled study of the use of HP in carotid endarterectomy. This study included 144 consecutive patients who had 151 CEAs with HP. Postoperative duplex ultrasounds were done at 1 month and every 6 months thereafter. The mean follow-up was 12 months (range: 1-30 months). Indications for CEA included symptomatic (64%) and asymptomatic (36%) stenoses. The overall incidence of ipsilateral stroke was 5% (4% perioperative), with a combined TIA and stroke rate of 12%. Incidence of > or =50% recurrent stenosis was 21% (7% symptomatic TIA/stroke) and > or =80% recurrent stenosis was 9%. Kaplan-Meier analysis showed that at 1 year and 2.5 years freedom from > or =50% recurrent stenosis was 78% and 57%, respectively, freedom from > or =80% recurrent stenosis was 92% and 77%, respectively, and a stroke-free survival rate of 94% and 72%, respectively. Women had a 22% and men a 14% recurrent stenosis rate (p=0.04). There was no correlation between other specific risk factors and recurrent stenosis except for hypertension (33% vs 12%, p=0.003). The authors concluded that CEA with HP had a higher incidence of recurrent stenosis (21%), and a higher perioperative stroke rate (4%) after a mean follow-up of 12 months than previously reported using PTFE or saphenous vein patching (2% and 9% recurrent stenosis rates, respectively, and 1% and 0% perioperative stroke rates, respectively after a mean follow-up of 30 months). This raises the question as to whether this patch is thrombogenic in this location. Therefore, a randomized controlled trial comparing this patch with other patches (PTFE or vein) is warranted.

Adult↗
PubMedDate not supplied

Coccygeal muscle injury in English Pointers (limber tail).

A condition colloquially referred to as "limber tail" and "cold tail" is familiar to people working with hunting dogs, primarily Pointers and Labrador Retrievers. The typical case consists of an adult dog that suddenly develops a flaccid tail. The tail either hangs down from the tail base or is held out horizontally for several inches from the tail base and then hangs straight down or at some degree below horizontal. Initially, the hair on the dorsal aspect of the proximal tail may be raised and dogs may resent palpation of the area 3-4 inches (8-10 cm) from the tail base. Most dogs recover spontaneously within a few days to weeks. Anecdotal reports suggest that anti-inflammatory drugs administered within 24 hours after onset hasten recovery. Less than one half of affected dogs experience a recurrence. Affected Pointers almost always have a history of prolonged cage transport, a hard workout the previous day, or exposure to cold or wet weather Most owners and trainers familiar with the condition do not seek veterinary assistance. In cases where people are not familiar with this disease, other conditions such as a fracture, spinal cord disease, impacted anal glands, or prostatic disease have been incorrectly diagnosed. We examined 4 affected Pointers and found evidence of coccygeal muscle damage, which included mild elevation of creatine kinase early after onset of clinical signs, needle electromyographic examination showing abnormal spontaneous discharges restricted to the coccygeal muscles several days after onset, and histopathologic evidence of muscle fiber damage. Specific muscle groups, namely the laterally positioned intertransversarius ventralis caudalis muscles, were affected most severely. Abnormal findings on thermography and scintigraphy further supported the diagnosis.

Animals↗