Biomedical subjects

T L Green

Publications and source records attributed to T L Green.

At least 19 recordsLinked to original sources

PubMed2004

Detection of histidine decarboxylase in rat aorta and cultured rat aortic smooth muscle cells.

OBJECTIVE: Having previously demonstrated release of histamine from mast-cell-deficient rat aorta, the objective of this study was to determine and localize histamine synthesis capability in the aorta by detecting histidine decarboxylase (HDC), the enzyme that catalyzes histamine formation. MATERIALS AND METHODS: Experiments were conducted with nested reverse transcription-polymerase chain reaction (nRT-PCR) to detect HDC mRNA and with immunofluorescence and western blot analysis to detect HDC protein in rat aorta, cultured rat aortic smooth muscle (RASMC) and endothelial cells (RAEC). RESULTS: Gel electrophoresis of nRT-PCR products indicated HDC mRNA in liver, aorta and RASMC but not in RAEC or kidney. Sequence analysis confirmed that the band observed in RASMC was the target HDC amplicon. Immunofluorescence indicated the presence of HDC protein in RASMC and not in RAEC. Western Blot analysis revealed HDC protein (55 kDa) in liver, aorta, RASMC but not in RAEC or kidney. CONCLUSIONS: The results of this study are the first to demonstrate the presence of HDC mRNA and protein in rat aorta and more specifically in RASMC, indicative of their capability to synthesize histamine.

Animals↗

PubMed2004

Trends in hospital admission for stroke in Calgary.

BACKGROUND: Stroke incidence has fallen since 1950. Recent trends suggest that stroke incidence may be stabilizing or increasing. We investigated time trends in stroke occurrence and in-hospital morbidity and mortality in the Calgary Health Region. METHODS: All patients admitted to hospitals in the Calgary Health Region between 1994 and 2002 with a primary discharge diagnosis code (ICD-9 or ICD-10) of stroke were included. In-hospital strokes were also included. Stroke type, date of admission, age, gender, discharge disposition (died, discharged) and in-hospital complications (pneumonia, pulmonary embolism, deep venous thrombosis) were recorded. Poisson and simple linear regression was used to model time trends of occurrence by stroke type and age-group and to extrapolate future time trends. RESULTS: From 1994 to 2002, 11642 stroke events were observed. Of these, 9879 patients (84.8%) were discharged from hospital, 1763 (15.1%) died in hospital, and 591 (5.1%) developed in-hospital complications from pneumonia, pulmonary embolism or deep venous thrombosis. Both in-hospital mortality and complication rates were highest for hemorrhages. Over the period of study, the rate of stroke admission has remained stable. However, total numbers of stroke admission to hospital have faced a significant increase (p=0.012) due to the combination of increases in intracerebral hemorrhage (p=0.021) and ischemic stroke admissions (p=0.011). Sub-arachnoid hemorrhage rates have declined. In-hospital stroke mortality has experienced an overall decline due to a decrease in deaths from ischemic stroke, intracerebral hemorrhage and sub-arachnoid hemorrhage. CONCLUSIONS: Although age-adjusted stroke occurrence rates were stable from 1994 to 2002, this is associated with both a sharp increase in the absolute number of stroke admissions and decline in proportional in-hospital mortality. Further research is needed into changes in stroke severity over time to understand the causes of declining in-hospital stroke mortality rates.

Alberta↗

PubMed2004

Predicting final disposition after stroke using the Orpington Prognostic Score.

BACKGROUND: Prediction of outcome after stroke is important for triage decisions, prognostic estimates for family and for appropriate resource utilization. Prognostication must be timely and simply applied. Several scales have shown good prognostic value. In Calgary, the Orpington Prognostic Score (OPS) has been used to predict outcome as an aid to rehabilitation triage. However, the OPS has not been assessed at one week for predictive capability. METHODS: Among patients admitted to a sub-acute stroke unit, OPS from the first week were examined to determine if any correlation existed between final disposition after rehabilitation and first week score. The predictive validity of the OPS at one week was compared to National Institute of Health Stroke Scale (NIHSS) score at 24 hours using logistic regression and receiver operator characteristics analysis. The primary outcome was final disposition after discharge from the stroke unit if the patient went directly home, or died, or from the inpatient rehabilitation unit. RESULTS: The first week OPS was highly predictive of final disposition. However, no major advantage in using the first week OPS was observed when compared to 24h NIHSS score. Both scales were equally predictive of final disposition of stroke patients, post rehabilitation. CONCLUSIONS: The first week OPS can be used to predict final outcome. The NIHSS at 24h provides the same prognostic information.

Activities of Daily Living↗

PubMed2003

Hemi-orolingual angioedema and ACE inhibition after alteplase treatment of stroke.

One hundred seventy-six consecutive patients treated with IV tissue plasminogen activator (tPA) for acute ischemic stroke were examined prospectively, and orolingual angioedema was found in nine (5.1%; 95% CI 2.3 to 9.5). The reaction was typically mild, transient, and contralateral to the ischemic hemisphere. Risk of angioedema was associated with angiotensin-converting enzyme inhibitors (relative risk [RR] 13.6; 95% CI 3.0 to 62.7) and signs on initial CT of ischemia in the insular and frontal cortex (RR 9.1; 95% CI 1.4 to 30.0).

Aged↗

PubMed2000

A Pseudomonas stutzeri gene cluster encoding the biosynthesis of the CCl4-dechlorination agent pyridine-2,6-bis(thiocarboxylic acid).

A spontaneous mutant of Pseudomonas stutzeri strain KC lacked the carbon tetrachloride (CCl4) transformation ability of wild-type KC. Analysis of restriction digests separated by pulsed-field gel electrophoresis (PFGE) indicated that the mutant strain CTN1 differed from strain KC by deletion of approximately 170 kb of chromosomal DNA. CTN1 did not produce pyridine-2,6-bis(thiocarboxylic acid) (PDTC), the agent determined to be responsible for CCl4 dechlorination in cultures of strain KC. Cosmids from a genomic library of strain KC containing DNA from within the deleted region were identified by hybridization with a 148 kb genomic Spel fragment absent in strain CTN1. Several cosmids identified in this manner were further screened for complementation of the PDTC biosynthesis-negative (Pdt -) phenotype. One cosmid (pT31) complemented the Pdt- phenotype of CTN1 and conferred CCl4 transformation activity and PDTC production upon other pseudomonads. Southern analysis showed that none of three other P. stutzeri strains representing three genomovars contained DNA that would hybridize with the 25,746 bp insert of pT31. Transposon mutagenesis of pT31 identified open reading frames (ORFs) whose disruption affected the ability to make PDTC in the strain CTN1 background. These data describe the pdt locus of strain KC as residing in a non-essential region of the chromosome subject to spontaneous deletion. The pdt locus is necessary for PDTC biosynthesis in strain KC and is sufficient for PDTC biosynthesis by other pseudomonads but is not a common feature of P. stutzeri strains.

Carbon Tetrachloride↗

PubMed1997

Radiographic and histologic periapical findings of root canal treated teeth in cadaver.

UNLABELLED: The success of root canal treatment can be subjectively evaluated both clinically and radiographically. Normally, the recall radiograph is the main factor in evaluating success or failure. OBJECTIVES: This study evaluated periapical areas of root canal treated teeth by correlating radiographic and histologic findings. STUDY DESIGN: Jaws were resected from cadavers and radiographed. Those teeth that had received root canal treatment were evaluated for success or failure based on radiographic criteria. Teeth and surrounding bone were then removed en bloc and prepared for light microscopy. Untreated teeth without periapical pathosis were examined as controls. RESULTS: Root canal treated teeth classified as failures were found to consistently have inflammatory resorptive lesions at the periapices. In contrast, those treated teeth classified as radiographically successful showed varying reactions ranging from normal uninflamed to mildly inflamed. CONCLUSIONS: Those classified as failure showed consistent inflammation. However, the majority of our examined treated teeth were radiographically normal and exhibited no periapical inflammation.

Cadaver↗

PubMed1996

Predicting cancer risk from vinyl chloride exposure with a physiologically based pharmacokinetic model.

A physiologically based pharmacokinetic (PBPK) model capable of describing the metabolism of vinyl chloride (VC) in rats, mice, and humans has been developed and validated by comparison with experimental data from experiments not used in model development. This PBPK model has been used to predict measures of delivered dose (reactive VC metabolites produced in the livers of the affected species) hypothesized to be involved in the induction of liver angiosarcoma in rats, mice, and human populations exposed to VC. Measures of delivered dose in rats were fit to an empirical dose-response model (the linearized multistage model of Crump et al.) and used to make predictions of liver angiosarcoma incidence in mice and human populations exposed to VC. This procedure gave a good prediction of angiosarcoma incidence in mice. Predictions of angiosarcoma incidence in humans were more than two orders of magnitude lower than risk estimations which did not utilize pharmacokinetic data, but were still almost an order of magnitude higher than actually observed in exposed human populations.

Animals↗

PubMed1995

Oral histoplasmosis in HIV-infected patients. A report of two cases.

Histoplasmosis is a fungal infection caused by the organism Histoplasma capsulatum. Disseminated disease usually occurs in immunosuppressed patients or in patients with chronic illnesses. Although relatively uncommon, histoplasmosis has been reported in patients with AIDS, and oral lesions have been noted on multiple sites and in various clinical presentations. We present two HIV-positive cases with oral lesions as the initial signs of histoplasmosis. Both patients responded well to IV amphotericin B but later suffered recurrences despite being maintained on systemic antifungal therapy.

AIDS-Related Opportunistic Infections↗

PubMed1992

Synthesis and assembly of the synaptic cleft protein S-laminin by cultured cells.

S-laminin, a homologue of the B1 chain of laminin, is concentrated in a subset of basal laminae (BLs), including the BL at the skeletal neuromuscular junction and bears an adhesive site for motoneuron-like cells. Here, we have begun to characterize the native form of the protein. We show that several muscle- and glia-like cell lines synthesize and secrete S-laminin as well as the A, B1, and B2 subunits of the conventional laminin trimer. Experiments using subunit-specific antibodies showed that S-laminin is complexed with the A and B2 subunits of laminin but not with B1, suggesting that S-laminin replaces B1 to form a novel laminin-like trimer. Comparison of material precipitated by different antibodies provided evidence for two immunochemically distinct forms of S-laminin, both of which associate with B2 and A-like subunits. Analysis of tunicamycin-treated cells indicated that N-linked glycosylation is required neither for the selective association of S-laminin with B2 and A subunits nor for the distinction between two forms of S-laminin. Finally, a full-length S-laminin cDNA was constructed and transfected into muscle and non-muscle cells. S-laminin was detected intracellularly in both cell types, in extracellular matrix of muscle cells, and in two immunochemically distinct forms. Thus, the cDNA contains sufficient information to permit assembly, secretion, and post-translational modification of S-laminin.

Animals↗

PubMed1992

Immunohistochemical evaluation of oral myxoid lesions.

Oral examples of neurothekeomas (nerve sheath myxomas), soft tissue myxomas, and focal mucinous and odontogenic myxomas were examined for selected markers. With the use of avidin-biotin complex staining procedures, these specimens of lesions were stained with antibodies to S-100 protein, neurospecific enolase, neurofilaments, desmin, and vimentin. Our results show that the use of immunohistochemical markers for these neural antigens can aid in distinguishing nerve sheath myxomas from other oral myxoid lesions.

Biomarkers, Tumor↗

PubMed1991

A comparison of substance P peptide and preprotachykinin mRNA levels during development of rat medullary raphe and neostriatum.

Substance P (SP) and the mRNA coding for its precursor peptide, preprotachykinin (PPT), were measured in medullary raphe nuclei (MRN) and neostriatum (NS) over development in order to determine (1) whether PPT mRNA levels correlate with peptide development, and (2) whether changes in PPT mRNA might help to account for the apparent decline in SP seen immunohistochemically in certain brain areas postnatally. Total RNA was quantified in dissected tissue pieces using the sensitive orcinol reaction. When MRN PPT mRNA levels measured by Northern blot analysis were adjusted to total RNA levels, PPT mRNA per MRN increased over development with a profile similar to that seen for SP peptide. Moreover, both peptide and mRNA levels exhibited a similar decline after postnatal day 15. Therefore, developmental regulation of SP biosynthesis in the MRN may, in part, explain previous evidence documenting a postnatal decline in SP there. In the NS, SP peptide and PPT mRNA increased with a similar profile from E18 through the first postnatal week. Thereafter, SP increased less rapidly than its mRNA, indicating incongruities in prohormone message and processed peptide in the NS.

Animals↗

PubMed1990

S-laminin.

Explore the source record for details and available documents.

Amino Acid Sequence↗

PubMed1989

Granuloma annulare of the buccal mucosa in association with AIDS.

This case report describes the occurrence of a lesion of granuloma annulare in the buccal mucosa. This skin condition occurs rarely on the mucous membranes and has not been previously described in the oral cavity. It was initially seen as a raised, firm lesion with a 1-month history in a 31-year-old patient with acquired immune deficiency.

Acquired Immunodeficiency Syndrome↗

PubMed1989

Oral lesions mimicking hairy leukoplakia: a diagnostic dilemma.

Oral hairy leukoplakia is seen in immunosuppressed persons infected with the human immunodeficiency virus and is a predictor of the development of acquired immunodeficiency syndrome in that population. Over the past 3 years we have seen 16 examples of a lesion that histologically resembles hairy leukoplakia but is found in patients who are not in risk groups for acquired immunodeficiency syndrome. All these specimens tested negative for Epstein-Barr virus DNA and for human papillomavirus antigen. Sera from five of the 16 patients were tested for antibodies to human immunodeficiency virus, and all results were negative. These findings suggest that the diagnosis of hairy leukoplakia cannot be based on histologic criteria alone but should be verified by DNA in situ hybridization for Epstein-Barr virus.

Adolescent↗

PubMed1989

Oral lymphomas in HIV-infected patients: association with Epstein-Barr virus DNA.

Nine instances of oral non-Hodgkin's lymphoma occurring in homosexual male patients infected with the human immunodeficiency virus were evaluated for clinical features, histopathologic features, lymphocyte phenotypic markers, and Epstein-Barr virus (EBV) DNA. Histologically, the tumors represented immunoblastic sarcoma and small noncleaved cell lymphomas, some manifesting Burkitt-like features. Five cases exhibited positive staining with monoclonal antibody L26, a B-cell marker; none of the tumors showed evidence of a T-cell lineage with the use of monoclonal antibody UCHL 1. DNA in situ hybridization studies disclosed the presence of EBV DNA sequences in seven instances. These findings indicate that most oral lymphomas among patients with AIDS, similar to extraoral lymphomas in this population, are of B-cell lineage and harbor EBV DNA.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Volar radiocarpal dislocation with ulnar translocation.

The first known reported case of volar radiocarpal dislocation with ulnar translocation is described with a review of previous literature on the isolated components of these injuries. Radiographic criteria for their diagnosis are presented with recommendations for early operative intervention to minimize the risk of subsequent carpal instability and provide an optimum functional result. An awareness of the possible coexistence of these injuries leading to early diagnosis and expedient treatment is essential to a good functional result.

Aged↗

PubMed1988

Kaposi's sarcoma in AIDS: basement membrane and endothelial cell markers in late-stage lesions.

Early-stage lesions of Kaposi's sarcoma (KS) are composed of single-layered, highly flattened cells lining collagen bundles, whereas late-stage lesions contain densely packed, spindle-shaped cells. We examined the progression of KS lesions in oral mucosa and lymph nodes from patients with AIDS, using antibodies specific for blood vascular endothelial cells (Factor VIII-related antigen) and their basement membrane (Type IV collagen and laminin). In addition, the plant lectin Ulex europaeus, which selectively stains blood vessels, was also used. In early-stage KS lesions, fibronectin, laminin and Type IV collagen were co-distributed at the interface between KS cells and collagen bundles; Factor VIII-related antigen and Ulex europaeus lectin staining was present in vascular channels and in the KS cells. However, in late-stage lesions, few if any KS cells stained with antibody to Factor VIII-associated antigen, although endothelial cells lining blood vessels were positive. Strong staining for laminin and Type IV collagen was present in a pericellular pattern throughout the nodular late-stage lesions. Since lymphatic capillary endothelium does not produce basement-membrane-specific macromolecules, these results support the conclusion that KS cells are related to blood vascular endothelium but eventually lose certain endothelium-specific markers as the cells are transformed into the spindle-shaped cell type.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Mutations in poly(A) site downstream elements affect in vitro cleavage activity.

Previous studies have shown that a sequence element downstream of the poly(A) addition site is required for efficient cleavage in vivo. We tested a group of downstream element point mutations in an in vitro reaction using HeLa cell nuclear extract as a source of cleavage activity. In close agreement with earlier studies (M. A. McDevitt, R. P. Hart, W. W. Wong, and J. R. Nevins, EMBO J. 5:2907-2913, 1986), a downstream element from the adenovirus E2a gene directed a higher level of cleavage activity than one from the simian virus 40 early gene. Furthermore, a single-base change in the downstream element could result in a decrease in cleavage activity of about 50-fold. That these mutations have similar effects in vivo and in vitro indicates that the HeLa cell nuclear extract system contains all of the factors required to study the mechanism of sequence recognition.

Adenovirus Early Proteins↗