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Biomedical subjects

J Harvey

Publications and source records attributed to J Harvey.

At least 127 records · Page 7Linked to original sources

A non-isotopic DNA hybridisation assay for the identification of Staphylococcus aureus isolated from foods.

A digoxygenin-labelled total genomic DNA probe was used to identify Staphylococcus aureus. Isolation and identification of organisms was possible in less than 4 days. Identification alone could be completed in less than 2 days, compared with over 5 days for identification of isolates by multipoint inoculation. The probe showed excellent discrimination of S. aureus from other staphylococci and from a wide range of bacteria commonly associated with milk and meat. The effectiveness of this probe was tested against cultural isolation of staphylococci in milk using Baird-Parker agar followed by identification using multipoint inoculation and API Staph. The probe gave comparable results to the conventional methods and, for large sample numbers, offered lower cost and greater ease of use.

Animals↗

Expression of epidermal growth factor receptor in invasive transitional cell carcinoma of the urinary bladder. A multivariate survival analysis.

Epidermal growth factor receptor (EGFR) immunoreactivity was evaluated in 85 cases of invasive transitional cell carcinoma of the bladder. The impact of EGFR staining on patient survival was compared with tumor stage, histologic grade, immunoreactivity for c-erb B-2 and proliferating cell nuclear antigen, flow cytometrically determined S-phase fraction and DNA ploidy, abnormal expression of blood-group-related antigens, and patient blood type. Using a new monoclonal anti-EGFR antibody reactive in formalin-fixed tissue, the authors found a significant correlation between EGFR expression and high tumor stage, and between EGFR expression and poor patient outcome. However, EGFR expression as a predictor of prognosis was not independent of stage. An intriguing association between patient blood type and patient survival was noted. Other indices did not predict patient outcome after data were adjusted for stage.

ABO Blood-Group System↗

The origin of 47,XXY and 47,XXX aneuploidy: heterogeneous mechanisms and role of aberrant recombination.

We investigated the parent and cell division of origin of the additional sex chromosome in 142 males with a 47,XXY constitution and 50 females with a 47,XXX constitution. In 66 of the 47,XXY males the additional chromosome was paternal in origin and in 76 it was maternal in origin, while among the 47,XXX females only 5 had an additional paternal X chromosome, the remaining 45 having an additional maternal chromosome. Among the 107 maternally derived aneuploids for whom it was possible to determine the cell division of origin, 73 were the result of a mat MI error, 24 the result of a mat MII error and 10 the result of a post zygotic mitotic (PZM) error involving the maternal X chromosome. Among those in which the non-disjunction was attributable to an error at the first meiotic division (MI) we observed three different mechanisms of origin. Approximately 30% were associated with complete absence of recombination (nullichiasmate); approximately 24% were associated with a normal number of recombinant events but an abnormal distribution of exchanges (perturbed recombination), while approximately 45% were associated with a normal number and distribution of recombinant events (normochiasmate). Nondisjunction due to an error at the second meiotic division (MII) was associated with a slight reduction in the total number of recombinant events and an abnormal distribution of exchanges. Thus of the four different meiotic mechanisms of origin, three were associated with an abnormal number and/or distribution of exchange events. There was no evidence of an increased paternal age in the aneuploids of paternal origin.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneuploidy↗

Breast cancer in Western Australia in 1989: III. Accuracy of FNA cytology in diagnosis.

A population-based study of all cases of breast cancer diagnosed in Western Australia (WA) in 1989 revealed 701 cases of cancer in 692 women. Three hundred and ninety-six (56.5%) of these cancers had fine needle aspiration (FNA) cytology. Forty-three cases were managed non-surgically, on the basis of an FNA diagnosis and without histologic follow up. Of the cases with histological follow-up, 73% received an unequivocal diagnosis of malignancy by FNA, and abnormal cells (atypical, suspicious or malignant diagnoses) were reported in 94.2%. Of the cases, 3.2% were reported as benign and in 2.6% the samples taken were unsatisfactory. There were no false positive cytological diagnoses of malignancy. This study is the first to examine the results of FNA diagnosis of breast cancer from a medical community as a whole, rather than for individual or specialist units; the accuracy of diagnosis was similar for different pathology practices including public and private sector laboratories. Lower absolute sensitivity (the proportion of cases given an unequivocal diagnosis of malignancy) was seen in very small and very large tumours, pure duct carcinoma in situ (DCIS), and invasive lobular carcinoma. False negative rates (the proportion of cases given a benign cytological diagnosis) were very low for all laboratories (0-4.5%) and for all types of carcinoma, and the proportion of unsatisfactory samples was exceptionally low for all laboratories (0-4.5%). The overall figures for accuracy are similar to those reported from other centres in Australasia and overseas, and confirm the effective use of FNA cytology throughout the clinical and pathology community in WA.

Adenocarcinoma, Mucinous↗

Application of multilocus enzyme electrophoresis and restriction fragment length polymorphism analysis to the typing of Listeria monocytogenes strains isolated from raw milk, nondairy foods, and clinical and veterinary sources.

The powerful discriminatory typing capabilities of multilocus enzyme electrophoresis and restriction fragment length polymorphism analysis were applied to Listeria monocytogenes strains from raw milk, nondairy foods, and clinical and veterinary sources. The raw milk and nondairy food strains were sequential isolates obtained over a year-long period from a number of different producers and manufacturers. Results obtained by the two typing methods were in substantial agreement and showed that both raw milk and nondairy foods frequently contain recurrent L. monocytogenes strains, thus suggesting that the presence of these organisms in such commodities often arises because of contamination from within their respective processing environments. Most recurrent strains were serogroup 1/2, with only one instance of recurrent serogroup 4 strains. Some recurrent L. monocytogenes strains, including the serogroup 4 strains, were found by analysis of multilocus enzyme electrophoresis results to be closely related to clinical and veterinary strains, thus suggesting that strains adapted for survival in the food-processing environment retain their potential for pathogenicity.

Animals↗

Hormone-regulated genes (pS2, PIP, FAS) in breast cancer and nontumoral mammary tissue.

Expression of the hormone-regulated genes, pS2, prolactin-inducible protein (PIP) and fatty acid synthetase (FAS), was investigated by Northern blotting in primary breast carcinoma, metastatic breast cancer in axillary lymph nodes, in uninvolved breast tissue from mastectomies and in normal lymph nodes. There were considerable differences in expression of the genes between the tissues. The proportion of tissues containing PIP-mRNA decreased from uninvolved breast tissue to primary breast carcinoma to metastatic carcinoma. The reverse applied to FAS-mRNA which was found more often in metastatic cancer than in primary cancer, and least frequently in uninvolved breast tissue. Yet another pattern was observed for pS2 expression. The highest proportion of tissues demonstrating gene expression was found in primary breast cancer with both metastatic tumor and uninvolved breast tissue expressing the gene less frequently. pS2-mRNA and PIP-mRNA could only rarely be detected in trace amounts in normal lymph nodes. In contrast, FAS-mRNA was present in about one third of normal lymph nodes. Only pS2-mRNA showed an association with estrogen and progesterone receptor status.

Blotting, Northern↗

Acute nitric oxide blockade amplifies the renal vasoconstrictor actions of angiotension II.

The tone in the renal vasculature is determined by the balance between vasoconstrictor and vasodilator agents. In this study, the effect on renal function was investigated when the acute blockade of the endogenous nitric oxide system was superimposed on a state of high circulating angiotensin II. Studies were conducted in the conscious, unstressed rat measuring renal function before and during acute systemic nitric oxide blockade with nitro-L-arginine methyl ester and with or without concomitant angiotensin II infusion. Nitric oxide blockade alone, in the presence of normal, unstimulated levels of endogenous angiotensin II, caused a large rise in blood pressure and a doubling of renal vascular resistance. The infusion of angiotensin II alone produced a mild rise in systemic blood pressure and a small (30%) rise in renal vascular resistance. When nitric oxide blockade was combined with angiotensin II infusion, the rise in blood pressure was similar to that produced by nitric oxide blockade alone but the increase in renal vascular resistance was much greater (350%), leading to marked declines in renal function. These studies demonstrate that when angiotensin II levels are acutely elevated and are controlling renal vascular tone, nitric oxide is essential for the maintenance of adequate renal perfusion and function.

Angiotensin II↗

Carbachol can potentiate N-methyl-D-aspartate responses in the rat hippocampus by a staurosporine and thapsigargin-insensitive mechanism.

Experiments were performed to investigate the mechanism underlying the potentiation of N-methyl-D-aspartate (NMDA) responses by carbachol (CCh) in the CA1 region of rat hippocampal slices. CCh (300 nM) potentiated responses to NMDA, but not to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), in a readily reversible manner. Potentiation occurred in slices treated with 200 nM tetrodotoxin and perfused with Mg(2+)-free medium. It also occurred in slices treated with either staurosporine (1 microM), which is a potent inhibitor of a variety of protein kinases including protein kinase C (PKC), or thapsigargin (10 microM), which depletes intracellular Ca2+ stores by preventing their refilling. However, CCh-induced potentiation was abolished in slices perfused with Ca(2+)-free medium. These data suggest that low concentrations of CCh can acutely potentiate NMDA responses in the hippocampus by a Ca(2+)-sensitive process that is probably independent of both the activation of PKC and the release of Ca2+ from intracellular stores. This mechanism is similar to that underlying the potentiation of NMDA responses by the metabotropic glutamate receptor (mGluR) agonist, aminocyclopentane-1S,3R-dicarboxylic acid (1S,3R-ACPD).

Alkaloids↗

Occurrence and characteristics of Listeria in foods produced in Northern Ireland.

The incidence of L. monocytogenes and other Listeria species was determined for 513 food samples produced in Northern Ireland. Selected L. monocytogenes isolates were typed using MEE and RFLP analysis. The overall incidence of Listeria in the foods examined was 35% (Listeria monocytogenes 18.3%). The incidence of Listeria and L. monocytogenes in four different food categories (graded I-IV according to decreasing extent of processing) being: I, 11.1% Listeria and 4.7% L. monocytogenes; II, 27.1% Listeria and 12.2% L. monocytogenes; III, 89.1% Listeria and 50% L. monocytogenes and IV, 100% Listeria and 100% L. monocytogenes. Within food categories I and II, the incidence of Listeria on occasions varied markedly between similar products produced by different processors. The most frequently isolated species was L. innocua, followed by L. monocytogenes, L. seeligeri and L. welshimeri. The L. monocytogenes isolates were predominantly serogroup 1. A modified USDA method was the most productive of four enrichment procedures investigated. Over the one-year duration of the survey, a distinctive Listeria microflora could be discerned in products from certain processors and was confirmed in some cases by MEE and RFLP typing of L. monocytogenes isolates.

DNA, Bacterial↗

Effects on food cravings of a very low calorie diet or a balanced, low calorie diet.

It is commonly believed that dieting and the restriction of specific types of foods produces cravings for these foods. This study, therefore, compared changes in self-reported cravings experienced by 93 obese subjects with Type II diabetes who were randomly assigned to behavioral treatment programmes which used either: (a) a balanced, low-calorie diet (LCD) of 1000-1200 kcal/day throughout, with all foods allowed in moderation, or (b) a programme which included a 12-week period of a very low calorie diet (VLCD), where intake was restricted to 400 kcal/day with only lean meat, fish, or fowl allowed. There were significant decreases in cravings for all types of foods over the 20 weeks of the study for both the VLCD and the LCD conditions. The decreases in cravings were particularly pronounced for the VLCD condition for low-fat, high-protein foods (the only foods allowed on the VLCD) and for complex carbohydrates, especially grains (one of the types of foods prohibited on this diet). There was no evidence to support the belief that restricting intake of certain foods leads to increased craving for these foods or that the magnitude of weight loss is related to food cravings.

Adult↗

Strengthening behavioral interventions for weight loss: a randomized trial of food provision and monetary incentives.

Behavioral treatments for obesity seek to modify eating and exercise behaviors by a change in their antecedents and consequences. More direct modification of antecedents and consequences by (a) the provision of food to patients and (b) the provision of financial rewards for weight loss was hypothesized to improve treatment outcomes. Two hundred two men and women were randomly assigned to no treatment, standard behavioral treatment (SBT), SBT plus food provision, SBT plus incentives, or SBT plus food provision and incentives. The major finding was that food provision significantly enhanced weight loss. Weight losses with SBT averaged 7.7, 4.5, and 4.1 kg at 6, 12, and 18 months, respectively, compared with 10.1, 9.1, and 6.4 kg, respectively, at the same intervals with the addition of food. Food provision also enhanced attendance, completion of food records, quality of diet, and nutrition knowledge. We conclude that the provision of food to weight-loss patients is a promising methodology that deserves further exploration.

Adult↗

Signal transduction pathways involved in the acute potentiation of NMDA responses by 1S,3R-ACPD in rat hippocampal slices.

1. A grease-gap recording technique has been used to investigate the mechanisms underlying the acute potentiation of N-methyl-D-aspartate (NMDA) responses by aminocyclopentane-1S,3R-dicarboxylic acid (1S,3R-ACPD) in area CA1 of rat hippocampal slices. 2. 1S,3R-ACPD (10 microM), but not 1R,3S- ACPD (10 microM), potentiated submaximal responses to NMDA (dose-ratio of 0.81 +/- 0.02 (mean +/- s.e.mean); n = 55), but not to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), in a readily reversible manner. Potentiation also occurred in slices treated with 0.2 microM tetrodotoxin, and in slices perfused with Mg(2+)-free medium. 3. 1S,3R-ACPD-induced potentiation was unaffected by the protein kinase inhibitors K-252b (0.1 microM) and staurosporine (1 microM) and the intracellular Ca2+ store depletor, thapsigargin (10 microM). Coapplication of staurosporine and thapsigargin was also without effect. 4. 1S,3R-ACPD-induced potentiation was unaffected by inhibitors of arachidonic acid formation, bromophenacyl bromide (50 microM) and RG80267 (100 microM). Arachidonic acid (10-50 microM) depressed reversibly NMDA-induced responses. The potentiation was unaffected by 8-bromo cyclic AMP (500 microM) or the PKA inhibitor Rp-adenosine 3,5-cyclic monophosphothioate triethylamine (Rp-cAMPS; 50 microM). 5. 1S,3R-ACPD-induced potentiation was abolished in slices perfused with Ca(2+)-free medium. The potentiation was also blocked by phorbol-12,13-diacetate (1 microM), in a staurosporine-sensitive manner. 6. It is concluded that the potentiation of NMDA responses by 1S,3R-ACPD is not mediated by protein kinase A or C, by release of Ca2+ from intracellular stores or by arachidonic acid. It involves a Ca2+-sensitive process and is negatively regulated by protein kinase C.

Animals↗

Development of a random amplification of polymorphic DNA typing method for Listeria monocytogenes.

The 10-mer primer OPM-01 (5'-GTT GGT GGC T-3') was used to generate random amplification of polymorphic DNA (RAPD) profiles by polymerase chain reaction for 91 strains of Listeria monocytogenes from raw milk, food, and veterinary, medical, and food-environmental sources. The profiles obtained contained 1 to 10 bands within the molecular size range of 0.5 to 5.0 kbp. Reproducibility was enhanced by annealing at low stringency and introducing a 1-min ramp time between annealing and extension temperatures. Thirty-three RAPD profiles were observed, with specific profiles being observed for strains from each source. RAPD profiles allowed discrimination within serogroups, although five RAPD profiles which were not confined to one serotype were found. Within food strains, one RAPD profile was more common than others, suggesting this to be a common type among strains from this source.

Bacterial Typing Techniques↗

Control of leukocyte integrin activation.

The integrin receptors on leukocytes are transiently activated by "triggering" molecules that may be other leukocyte membrane structures such as the T-cell receptor complex or small molecules such as PAF, which bind to their own specific receptors. This "inside out" signaling is essential for high affinity integrin/ligand pairing. In the example of LFA-1/ICAM-1, binding is positively supported by Mg2+ but negatively supported by Ca2+. How specific divalent cations affect receptor activation and subsequent ligand binding has still to be fully understood. However, the fact that activation can be mimicked from outside the cell via special anti-LFA-1 monoclonal antibodies such as MEM-83 suggests that activated integrins undergo conformational changes. Further alteration occurs as a result of the interaction of integrin with ligand, and the resulting novel epitopes are named "ligand-induced binding sites." For a brief period of time the integrin/ligand complex is able to transmit signals from "outside in." The transient activation of leukocyte integrins determines that cell-cell adhesion will be short lived and serves the purpose of permitting recycling of effector cells with their targets.

Animals↗

Lack of efficacy of intrapleural bupivacaine for postoperative analgesia following thoracotomy.

Intrapleural bupivacaine has been reported to be effective for analgesia following cholecystectomy and thoracic surgery. Twenty patients who had a posterolateral thoracotomy were studied in a randomized, double-blind, placebo-controlled fashion. Patients were assigned to receive intrapleural administration of either 0.5 percent bupivacaine or saline solution every 4 h for 12 doses postoperatively, as well as narcotic analgesics as needed for additional pain control. Pain was assessed using a visual analogue scale. Narcotic analgesic use, duration of hospitalization, and the development of complications were recorded. There were nine evaluable patients who received bupivacaine, and ten patients who received placebo. The age, sex, and type of operation were similar in the two groups, and the procedures were performed by the same two surgeons. The mean pain score at 24 h postoperatively was 5.8 +/- 0.8 in the bupivacaine group and 6.0 +/- 0.6 in the placebo group. At 48 h, the scores were 4.6 +/- 0.8 in the bupivacaine group and 5.1 +/- 0.9 in the placebo group. The mean dose of morphine sulfate or equianalgesic dose of meperidine during the first 24 h was 13.9 +/- 3.7 mg in the bupivacaine group and 12.6 +/- 1.8 mg in the placebo group, and during the next 24 h it was 40.0 +/- 13.4 mg in the bupivacaine group and 38.0 +/- 9.2 mg in the placebo group. The mean duration of hospitalization was 12.8 +/- 3.2 days in the bupivacaine group and 12.1 +/- 2.9 days in the placebo group. Two patients who received bupivacaine and three patients who received placebo had development of pneumonia or atelectasis postoperatively. There was no statistically significant difference in any parameter between those who received bupivacaine and those who received placebo. Thus, there was no subjective or objective clinical benefit of this method of postoperative analgesia compared with placebo following posterolateral thoracotomy.

Analgesia↗

Expression of the pS2 gene in breast cancer--a comparison of pS2 protein radioimmunoassay and immunohistochemistry.

pS2 expression was studied in a series of 82 primary breast carcinomas using and comparing a radioimmunoassay (RIA) technique and immunohistochemistry (IPOX). There was close correlation of the results obtained with each technique. Accurate and reliable determination of pS2 status in breast cancer can be made on the basis of immunohistochemistry using formalin fixed paraffin embedded sections. Immunohistochemical determination of pS2 status may be used in situations where the RIA technique cannot be applied, i.e. instances when fresh tumor tissue is not available.

Breast Neoplasms↗