Search PubMed⌕ Search

Biomedical subjects

P Price

Publications and source records attributed to P Price.

At least 181 records · Page 10Linked to original sources

Anatomic variance in the cholecystic blood supply: a case report.

The cystic artery is known to arise from many possible origins; with the right hepatic artery is the most common. Other origins of the cystic artery include the left hepatic artery, the common hepatic artery, and the superior mesenteric artery. In addition to the variability in origin of the cystic artery, its course can also follow diverse paths, often in close proximity to the common bile duct. This report presents a rare and, to our knowledge, previously unreported deviation of the cystic artery's origin and course that was encountered during cholecystectomy. This rare variant emphasizes the importance of a thorough knowledge of cystic arterial variations that often occur and may be encountered during both open and laparoscopic cholecystectomy.

Aged↗

Misuse of the emergency department by the elderly population: myth or reality?

OBJECTIVE: To determine the use pattern of the emergency department by people 65 years of age and older. DESIGN: Cross-sectional survey from chart audits and personal interviews of all people older than 64 years attending an emergency department in a Canadian teaching hospital. PARTICIPANTS: All patients older than 64 years attending the emergency department during the months of February, May, August, and November. Comparison samples of adults aged 16 to 64 years attending the same emergency department and patients older than 64 years attending the emergency department of a similar hospital during the same period were obtained. RESULTS: Fifteen percent of the total population attending the emergency department in 1 year were 65 years of age and older (N = 1744). The average age was 75 years; 57% were female, 53% were married, and 40% were widowed. Eighty-four percent lived in their own homes and 6% lived in nursing homes. Twenty-two percent were classified as emergent, 75% as urgent, and 3% as deferrable; 45% were admitted. The discharge diagnoses were widely divergent, with the most common being soft-tissue injury (9.1%), fracture (7.1%), arteriosclerotic heart disease (6.1%), congestive heart failure (4.1%), and abdominal pain (3.4%). Patients tended to appear in the emergency department more frequently during the day shift (60%) and less frequently on weekends. Forty-five percent had never attended the emergency department or been admitted to hospital in the previous year; 30% had attended or been admitted once. CONCLUSION: Elderly persons do not misuse the services of the emergency department. They come because they are acutely ill; they are not frequent attenders, and their presenting complaints do require intervention (frequently hospitalization). The study findings are generalizable to the older population in the Hamilton-Wentworth region and raise such questions as whether some hospital admissions could have been avoided by earlier interventions in the community.

Adult↗

The effects of beta-2-microglobulin on the infectivity of murine cytomegalovirus.

The role of beta-2-microglobulin (beta 2m) in murine cytomegalovirus (MCMV) infection of susceptible (H-2d) and resistant (H-2k) murine embryo fibroblasts (MEF) and peritoneal macrophages was evaluated using serum-free virus (SF-MCMV). The infectivity of SF-MCMV was significantly lower than virus propagated in serum, although the concentrations of virions were similar. Infection of cells with SF-MCMV was assessed by measuring the proportion of cells expressing viral antigens, the sizes of plaques formed in fibroblast monolayers and TCID50 titers. Infection of susceptible fibroblasts was significantly increased 1.6-4.7 fold by the addition of whole FCS, a less than 20 kDa FCS fraction, or purified human beta 2m. These supplements also significantly enhanced infection of susceptible macrophages and increased TCID50 titers by 3.5-10 fold in susceptible MEF. In relatively resistant H-2k cells, the TCID50 titer and the proportion of cells expressing viral antigens after infection with SF-MCMV were not affected by beta 2m or FCS, but plaque sizes were increased 2.5-3 fold in resistant BALB.K MEF. When human or murine beta 2m was added to infected cultures, immunogold electron microscopy revealed these proteins to be always associated extracellularly with the tegument material of disrupted multicapsid virions, but rarely with the envelope of intact virions. However, no murine beta 2m was found in association with the envelope or tegument of SF-MCMV. These relatively modest effects of beta 2m which were restricted to genetically susceptible cells, may be due to tegument-bound beta 2m facilitating infection by capsids, or the stabilisation of the conformation of Class 1 molecules by exogenous beta 2m, promoting MCMV binding to the target cell.

3T3 Cells↗

A prospective randomised trial of 4 Gy or 8 Gy single doses in the treatment of metastatic bone pain.

270 patients with painful bone metastases requiring palliative radiotherapy were randomised to receive single fractions of 4 Gy or 8 Gy in a randomised trial. Pain scores and analgesic usage were recorded before treatment and at 2, 4, 8 and 12 weeks. Pain was assessed by patients on a 4 point graded scale using pain charts administered by a central trials office. Response was defined as an improved rating compared to the pretreatment value. Compliance with the pain chart was 72% at 4 weeks. At 4 weeks, the actual response rates were 69% for 8 Gy and 44% for 4 Gy (p less than 0.001), but there was no difference in complete response (no pain) rates at 4 weeks or duration of response between the two arms. It is concluded that 8 Gy gives a higher probability of pain relief than 4 Gy, but that 4 Gy can be an effective alternative in situations of reduced tolerance.

Bone Neoplasms↗

Suppression of thromboxane A2 but not of systemic prostacyclin by controlled-release aspirin.

BACKGROUND: The antithrombotic efficacy of aspirin is attributed to its inhibition of the enzyme prostaglandin G/H synthase, which is necessary for the formation of thromboxane A2 in platelets. Thromboxane A2 is a potent vasoconstrictor and platelet agonist. However, the formation of prostacyclin by vascular endothelium also requires prostaglandin G/H synthase, and prostacyclin exerts opposite effects on platelet function and vascular tone. We wanted to see whether controlled-release aspirin would affect the formation of thromboxane A2 but not prostacyclin by reducing the aspirin concentration that reaches the posthepatic circulation. METHODS: A controlled-release formulation containing 75 mg of aspirin, designed to release 10 mg per hour, was developed to inhibit prostaglandin G/H synthase in platelets in the prehepatic circulation. The effects of the controlled-release preparation on plasma levels of aspirin and salicylate, serum levels of thromboxane B2, and urinary dinor metabolites of prostacyclin and thromboxane B2 (measured by gas chromatography-mass spectrometry) were compared with those of conventional immediate-release aspirin in normal volunteers. Prostacyclin release was stimulated by intravenous bradykinin. RESULTS: Steady-state inhibition of serum thromboxane B2 required two to four days and appeared slower with 75 mg of controlled-release than with the same amount of immediate-release aspirin. Maximal inhibition was achieved rapidly by adding a single loading dose of 162.5 mg of immediate-release aspirin to the regimen. Over a 28-day period, suppression of thromboxane A2 with this regimen was comparable to that with immediate-release aspirin taken either as 162.5 mg daily or as 325 mg on alternate days, despite the minimal systemic bioavailability of controlled-release aspirin. Bleeding time was prolonged to a similar degree with each of the three regimens. The five- to sixfold increase in the prostacyclin metabolite induced by bradykinin was depressed by pretreatment for four days with 75 mg of immediate-release aspirin, but not by 75 mg of controlled-release aspirin. CONCLUSIONS: Maximal inhibition of platelet thromboxane A2 production was sustained during long-term dosing with controlled-release aspirin, whereas basal prostacyclin biosynthesis fell only slightly and systemic synthesis of prostacyclin stimulated by bradykinin was preserved. Controlled-release aspirin may facilitate determination of the clinical importance of preserving prostacyclin during platelet inhibition in humans.

Adolescent↗

Evaluation of cell attachment matrix (CAM) coated plates for primary culture of human tumour biopsies.

Baker et al. [Cancer Res. 46: 1263-1274, 1986] developed an adhesive tumour cell culture system (ATCCS) using a culture surface coated with a cell attachment matrix (CAM). The ability of CAM-coated plates to support the growth of cells from human tumour biopsies has been evaluated. Successful growth was obtained in 9/22 samples (41%), but fibroblasts, rather than tumour cells, grew in the majority. Comparison of CAM with other surfaces showed that CAM was no better for establishing tumour cell growth than the presence of feeder cells or an alternative attachment factor vitronectin.

Animals↗

Modulation of immunocompetence by cyclosporin A, cyclophosphamide or protein malnutrition potentiates murine cytomegalovirus pneumonitis.

Following intranasal infection with murine cytomegalovirus (MCMV), the levels of viral replication in the lungs of susceptible BALB/c mice were enhanced by treatment with cyclophosphamide (CY), or to a greater extent cyclosporin A (CsA) or the Nu/Nu genotype. Focal inflammation was seen 2-4 days after infection in all groups. This was followed by diffuse interstitial pneumonitis which cleared 12-20 days later in the absence of immunosuppression. Although the initial foci of inflammation were less prominent in infected mice treated with CY or CsA, the most severe interstitial pneumonitis was seen 7 days p.i. in mice given CY, whilst CsA-treatment produced focal and disseminated pneumonitis 7-14 days p.i. and Nu/Nu mice exhibited only the focal response. MCMV-infected mice maintained from weaning on a low protein (4% casein) diet also retained higher titres of virus in their lungs than did normally-fed controls, and displayed more prominent focal pneumonitis.

Animals↗

Proliferation in human bladder carcinoma measured by Ki-67 antibody labelling: its potential clinical importance.

Ki-67 is a monoclonal antibody which recognises a human nuclear antigen expressed in proliferating cells. The antibody was used to assess proliferation in primary human bladder tumours from 64 patients. Ki-67 index (the number of Ki-67 positive tumour cells divided by the total number of tumour cells %) was derived from 59 tumours. A wide range of Ki-67 indices were recorded, range 3.0-65.8%, mean 20.2%. The Ki-67 index correlated with known prognostic factors: T stage (P = 0.002) and histological grade (P less than 0.001), early stage disease and more differentiated tumours having lower Ki-67 indices. Patients with invasive disease (21 patients) had significantly higher Ki-67 indices than those with non-invasive disease (P = 0.01). Patients with metastatic disease at presentation (four cases) all had a Ki-67 index of greater than or equal to 29%. Ki-67 antibody staining is a simple technique for assessing the proliferation fraction than can be performed on a small amount of tissue taken at routine biopsy without prior injection of thymidine analogues.

Aged↗

Potentiation of murine cytomegalovirus pneumonitis by antibiotics in clinical use.

Nineteen antibiotics were screened for their effects on the proliferation of murine spleen cells in vitro. Ketoconazole suppressed lymphoproliferation at clinically-attainable concentrations, whilst tetracycline, cephalothin, rifampicin and ciprofloxacin were also inhibitory at relatively low concentrations. These antibiotics were selected for further study. High concentrations of cephalothin inhibited macrophage uptake of colloidal gold, while spleen cells from mice treated with ketoconazole responded poorly to mitogenic stimulation in vitro. Humoral responses to ovalbumin, polyvinylpyrrolidone and murine cytomegalovirus (MCMV) were not suppressed by oral administration of ketoconazole, tetracycline, cephalothin, rifampicin or ciprofloxacin to mice. However, MCMV-infected mice receiving these antibiotics had increased virus loads and a greater persistence of virus and interstitial pneumonitis in their lungs. This was observed with clinically-attainable serum concentrations of cephalothin, tetracycline and ciprofloxacin. The findings warrant further investigation as the antibiotics are used to control secondary infections in immunosuppressed patients, many of whom experience cytomegalovirus disease.

Animals↗

Cell proliferation in human tumour xenografts: measurement using antibody labelling against bromodeoxyuridine and Ki-67.

Cell proliferation was investigated in human tumour xenografts using bromodeoxyuridine (BrdUrd) labelling, evaluated either by flow cytometry or in tissue sections, and also using the proliferation marker Ki-67. BrdUrd labelling was found to increase when cryostat tumour sections were digested with an enzymic solution. This yielded a labelling index up to four times higher than that obtained using the flow cytometer. Ki-67 indices were found to be higher than those reported for human tumour biopsies, as may be expected due to the enhanced growth rate of the xenografts. Significant heterogeneity was observed in the results for cervix, breast and bladder tumours, and the results of the three methods were poorly correlated. However, three of the four tumour types showed that the tumour with the lowest Ki-67 index also had the longest potential doubling time. Since the measurement of Ki-67 index was found technically easier to perform, and also adequately reflects relative tumour cell proliferation, it is preferred over the other techniques.

Animals↗

The effects of protein malnutrition on the pathogenesis of murine cytomegalovirus disease.

BALB/c and CBA mice maintained on low (4%) or normal (18%) protein diets for 2 weeks after weaning were infected with a sublethal dose of murine cytomegalovirus, adjusted in proportion to body weight. Viral replication, histopathological changes and humoral responses to the virus were compared between the dietary groups 2-42 days post infection (p.i.). Higher numbers of viral antigen-positive cells and/or more prominent tissue necrosis were noted in the livers, spleens, hearts, adrenal glands, kidneys and bone marrows of infected protein-deficient mice. These mice also showed a delayed onset of leucocytic exudation in their livers and salivary glands, relative to infected mice on the normal diet. Second peaks of viral replication were detected by plaque assays in livers and spleens from protein-deficient mice and in livers from normal mice 12-18 days p.i., but few antigen-positive cells and no tissue necrosis were observed. Virus also persisted at higher titres in the salivary glands from protein-deficient mice. Although cellular immunity may be defective in these mice, humoral IgG and IgM responses to the virus were not inhibited. The influence of genetic factors on the pathogenesis of murine cytomegalovirus disease in protein-deficient mice is discussed.

Animals↗

Genetic determination of cytomegalovirus-induced and age-related cardiopathy in inbred mice. Characterization of infiltrating cells.

Carditis developed 7 days after the administration of murine cytomegalovirus to neonatal, young adult or aged mice of varying sensitivity to lethal infection with this virus. The inflammation persisted for up to 80 days, but infected myocardial cells were rare and were not seen after day 10. The inflammatory cells comprised macrophages (up to 30%) and T cells (up to 80%), with a high ratio of Lyt2+ to L3T4+ cells throughout. Although the H-2 genotype affects murine cytomegalovirus replication at the level of individual cells, and hence resistance to lethal infection, it did not determine resistance to cardiopathy per se. However BALB/c, BALB.B, and BALB.K mice developed persistent myocarditis regardless of age at infection, and age-related cardiopathy was frequent and severe in infected and uninfected mice. B10 and B10.BR mice also developed myocarditis after neonatal infection, but inflammation resolved rapidly after adult infection and age-related cardiopathy was correspondingly mild. C3H mice exhibited minimal carditis after neonatal or adult infection. However neonatal infection appears to accelerate age-related cardiopathy, which is severe in retired breeders of this strain.

Aging↗

Use of the tetrazolium assay in measuring the response of human tumor cells to ionizing radiation.

Three human tumor cell lines of widely differing radiosensitivity were used to examine the characteristics of the 3-[4,5-dimethyl(thiazol-2-yl)-3,5-diphery]tetradium bromide (MTT) assay and to select suitable conditions for its use in assessing the response of cells to ionizing radiation. The optimal concentration of MTT and the time of incubation of the cells with MTT were individualized for each cell line. The relationship between absorbance and cell number was not linear over the wide range of cell numbers that were used. A calibration curve of absorbance against cell number for each cell line was therefore used. Using the assay to quantify metabolically viable cells, growth curves of irradiated and unirradiated cells were constructed on days 0-14 after irradiation. Accurate surviving fractions could be calculated only when cells were in exponential growth. Using this modification to its interpretation, the MTT assay was able to provide a reproducible measure of survival, which compared well with clonogenic cell survival measurements. However, the necessity to optimize conditions of the MTT assay for each cell line severely limits its usefulness in determining the radiosensitivity of cells in primary human tumor cultures.

Carcinoma, Transitional Cell↗

Replication of murine cytomegalovirus in mast cells.

Mast cells purified from the peritoneal cell population and mast cells derived in culture from bone marrow cells were examined for their sensitivity to murine cytomegalovirus (MCMV) infection in vitro. While up to 70% of mast cells expressed viral antigens, less than 12% of the cells produced infectious virus. Transmission electron microscopy demonstrated nucleocapsids in the nuclei and in association with the cisternal elements of the Golgi apparatus. Some complete virions were found within small cytoplasmic vacuoles. In contrast with previous studies of macrophages and fibroblasts, the susceptibility of mast cells to MCMV infection in vitro was not influenced by the H-2 or non-H-2 genotype of the donor.

Animals↗

H-2 class I loci determine sensitivity to MCMV in macrophages and fibroblasts.

Peritoneal (PM) and bone marrow-derived (BMM) macrophages and lung fibroblasts (LF) from inbred, intra-H-2 recombinant, H-2 mutant, and hybrid mice were infected with murine cytomegalovirus (MCMV) under centrifugal enhancement. At the concentration of virus employed, peritoneal macrophages from strains carrying Kd, Kb, Dd, Ks and/or Ds, Kq and/or Dq alleles could be infected to a level of 80%-100%, as assessed by viral antigen expression or loss of Fc receptors. Cells lacking these haplotypes and carrying Kk, Kj, Dk, Dj, or Db were resistant, yielding levels of infection below 20%. The background (non-H-2) and class II genotype and the S allele did not influence the proportions of cells infected. Furthermore, sensitivity was dominant in the F1 progeny of H-2b X H-2k and H-2d X H-2k crosses, and was not compromised by the bm1, bm3, bm10, or bm14 mutations in the alpha 1 or alpha 2 regions of Kb or Db. The proportions of cells able to release infectious virus were low, but paralleled the frequencies of viral antigen expression. The class I genotype also determined susceptibility to MCMV infection in BMM and LF, although up to 35% of H-2k BMM and 46% of H-2k LF could be infected. The findings are consistent with an association between K and D antigens and a cellular receptor for MCMV on all three cell types.

Animals↗