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Biomedical subjects

B Weeks

Publications and source records attributed to B Weeks.

11 recordsLinked to original sources
PubMed2001

Small intestine large granular lymphoma in a horse.

A 12-year-old Appaloosa gelding was referred to the Texas Veterinary Medical Center with a history of chronic diarrhea and weight loss. At necropsy, numerous oval, craterlike ulcers were observed throughout the small intestine. Histologically, these lesions were composed of a neoplastic proliferation of round cells with intracytoplasmic phosphotungstic acid-hematoxylin-positive granules. The tumor cells stained positively for the CD3 antigen and negatively for a B-cell marker. A diagnosis of large granular lymphoma was based on the morphologic and immunohistochemical characteristics of the neoplasm. The postmortem presentation of this case depicted unusual multifocal, ulcerative lymphomatous lesions throughout the small intestine without involvement of the regional lymph nodes. The histologic and ultrastructural morphology of the neoplastic lymphocytes was similar to that in previously reported cases of abdominal equine large granular lymphomas, but in this case the neoplasm was restricted to the small intestine.

Animals↗
PubMed2000

Nociceptin, endomorphin-1 and -2 do not interact with invertebrate immune and neural mu 3 opiate receptor.

AIM: To determine if endomorphin-1, -2 and nociceptin (orphanin FQ) bind to the mu 3 opiate receptor subtype or release nitric oxide as mu 3 selective ligands do. METHODS: These opioid peptides were examined for their ability to displace [3H]dihydromorphine (DHM) binding from the invertebrate (immunocytes and pedal ganglia) mu 3 opiate receptor in membrane homogenates. The ligands were also tested for their ability to release nitric oxide from the same intact tissues utilizing an amperometric probe that measures nitric oxide in real-time. RESULTS: Endomorphin-1, -2 and nociceptin do not displace [3H]DHM binding from immunocyte or pedal ganglia membrane homogenates nor do they release nitric oxide from these tissues. CONCLUSION: Since these newly discovered opioid peptides do not interact with the mu 3 opiate receptor subtype, endogenous morphine's significance is enhanced because it appears to be the only naturally occurring opiate ligand for the receptor. Furthermore, since this study involves invertebrate tissues, this signal system had to evolve early during evolution.

Analgesics, Opioid↗
PubMed1997

Mapping regions of herpes simplex virus type 1 glycoprotein I required for formation of the viral Fc receptor for monomeric IgG.

Glycoprotein E (gE) and glycoprotein I (gI) of herpes simplex virus type 1 (HSV-1) form a complex that binds the Fc domain of monomeric IgG. In this study, we used two approaches to map the regions of gI-1 required for formation of the HSV-1 Fc receptor for monomeric IgG. First, we constructed six plasmids encoding gD-1/gI-1 fusion proteins. Each fusion protein contains a large gI-1 peptide inserted into the ectodomain of gD-1. gD-1/gI-1 fusion proteins were coexpressed with gE-1 using a transfection-infection assay in which cells were transfected with individual fusion protein constructs and then infected with a gE+/gI- virus. Cells were then assayed for monomeric IgG binding using immunofluorescence microscopy. Transfection-infection with two of six fusion proteins conferred monomeric IgG binding activity to cells, whereas cells infected with gE+/gI- virus alone failed to bind IgG monomers. The smallest gI-1 peptide to confer monomeric IgG binding activity contained amino acids 43 to 192. To more precisely map the region of gI-1 required for monomeric IgG binding, we constructed a panel of 10 gI-1 linker insertion mutants. Transfection-infection studies identified two mutants containing linker insertions at gI-1 amino acids 128 and 145, which failed to bind monomeric IgG. The other eight mutants demonstrated wild-type IgG binding activity. Taken together, these results indicate that the region of gI-1 between amino acids 128 and 145 is required for formation of the HSV-1 Fc receptor for monomeric IgG.

Animals↗
PubMed1995

A physical examination of health care's readiness for a total quality management program: a case study.

Initiating a total quality management (TQM) effort can be a time-consuming and costly effort for a hospital. Perceptions of management and employees are important in initiating TQM because people function as if perceptions are fact. Assessing these perceptions and determining the levels of readiness or resistance to change are important steps in reducing costs, thus increasing organizational ability to address proactively challenges to the implementation and ultimate success of a TQM effort. Key assessment criteria are discussed including a comparison of management and employee perceptions in one hospital.

Efficiency, Organizational↗
PubMed1989

A synthetic peptide containing the IKVAV sequence from the A chain of laminin mediates cell attachment, migration, and neurite outgrowth.

Laminin is a basement membrane glycoprotein which consists of A, B1, and B2 chains. Laminin has diverse biological activities including promoting cell adhesion, migration, differentiation, growth, and neurite extension. Synthetic peptides from the active region of the A chain were prepared and tested for their biological activity. A 19-mer peptide (designated PA22-2), from just above the carboxyl globule on the long arm of the A chain, was found to promote cell adhesion, spreading, migration, and neurite outgrowth. By testing smaller sequences within the 19-mer peptide, a constituent pentapeptide, IKVAV (Ile-Lys-Val-Ala-Val), was identified as the active site for cell adhesion and neurite outgrowth. These data suggest that this sequence is one of the principle sites in laminin which regulate cellular behavior.

Adrenal Gland Neoplasms↗
PubMed1980

Vectorcardiographic analysis of ventricular tachycardia.

From a study of 69 patients with ventricular tachycardia using digitised vectorcardiograms, it is suggested that the following features are evidence of a ventricular origin. 1. Anterior QRS predominantly in the left anterior quadrant. 2. Slow initial tangential QRS velocity greater than or equal to 20 ms in the presence of an anterior QRS monophasic loop. 3. QRS totally in the right posterior quadrant. 4. In the presence of a QRS in the left posterior quadrant slow anterior QRS initial forces lasting greater than or equal 20 ms in the horizontal plane. The following features are suggestive of a ventricular origin. 1. Slow initial tangential QRS velocity greater than or equal to 20 ms in the presence of an anterior QRS loop resembling right bundle branch block (RBBB). 2. Anterior monophasic QRS loop with counterclockwise rotation. 3. Slow initial QRS forces posteriorly (TV of first 40 ms less than 10 mV . s-1) in the presence of a QRS loop in the left posterior quadrant. 4. A vertical right QRS axis greater than or equal to +60 degrees in the presence of a left bundle branch block (LBBB) loop in the horizontal plane and any axis greater than or equal to +90 degrees less than or equal to -160 degrees. The importance of three simultaneous perpendicular leads for recording or arrhythmias is stressed. In addition vectorcardiograms have clearly separated multifocal ventricular tachycardia from multiformity, fusion beats with and without aberration, and bundle branch ventricular tachycardia. It is suggested that further study of the QRS waveform at the initiation and termination of ventricular tachycardia will elucidate the mechanisms and types of tachycardias.

Diagnosis, Differential↗
PubMed1980

QRS waveform of ventricular extrasystoles and their differentiation from aberrant conduction.

Horizontal and frontal plane QRS loops of patients in sinus rhythm with uniform ventricular extrasystoles were constructed from digitised Frank orthogonal electrocardiogram. In 4 patients ventricular extrasystoles were indistinguishable from right bundle-branch complexes, and in another 4 from left bundle-branch complexes. In 25 patients ventricular extrasystoles showed an initial delay (greater than or equal to 20 msec) of the QRS, followed by an R loop, which in 13 patients resembled LBBB complexes, and 12 patients resembled RBBB complexes with an anterior clockwise loop in the horizontal plane. However, the frontal plane loop was often atypical of either RBBB or LBBB. In 51 patients ventricular extraplane loop was often atypical of either RBBB or LBBB. In 51 patients ventricular extrasystoles and an initial delay which was prolonged into the efferent limb of the QRS loop with acceleration of the afferent limb and/or the QRS loop was directed anteriorly, inferiorly and to the left. Conventional recordings of these extrasystoles usually showed an initial slow upstroke (or downstroke) of the QRS resembling a delta wave. It is suggested that extrasystoles resembling bundle-branch complexes arise close to the main bundle branches but that the other extrasystoles arise at the Purkinje-myocardial junction. Identification and differentiation of ventricular extrasystoles from aberrant conduction is aided by vectorcardiography.

Bundle-Branch Block↗
PubMed1978

Vectorcardiographic features of ventricular extrasystoles correlated with conventional scalar electrocardiographic interpretation.

Horizontal and frontal plane QRS loops of patients in sinus rhythm with uniform ventricular extrasystoles were constructed from digitised Frank orthogonal electrocardiograms. In 4 patients ventricular extrasystoles were indistinguishable from right bundle-branch complexes, and in another they were indistinguishable from left bundle-branch complexes. In 25 patients ventricular extrasystoles showed an initial delay (greater than or equal to 20 ms) of the QRS, followed by an R loop, which in 13 patients resembled left bundle-branch block complexes, and in 12 patients resembled right bundle-branch block complexes, with an anterior clockwise loop in the horizontal plane. However, the frontal plane loop often did not resemble that of either right or left bundle-branch block. In 51 patients ventricular extrasystoles had an initial delay which was prolonged into the efferent limb of the QRS loop with acceleration of the afferent limb, and/or the QRS loop was directed anteriorly, inferiorly, and to the left. Conventional recordings of these extrasystoles usually showed an initial slow upstroke (or downstroke) of the QRS resembling a delta wave. Apparently uniform ventricular extrasystoles on scalar recordings were shown to be multiform vectorcardiographically though in all such cases the direction of the initial 40 ms forces was constant. It is suggested that the slow initial inscription of ventricular extrasystoles is the result of excitation of ventricular muscle directly and not through specialised His-Purkinje fibres, and that the direction of such initial forces may indicate the ventricular origin of ventricular extrasystoles.

Bundle-Branch Block↗