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Biomedical subjects

A Millar

Publications and source records attributed to A Millar.

At least 19 recordsLinked to original sources

Regioselective palladium-catalyzed arylation of 2-furaldehyde.

An efficient regioselective method for the direct arylation of 2-furaldehyde to provide a range of pi-diverse 5-aryl-2-formylfuran derivatives is described. The method employs functionalized aryl halides and a catalytic amount of palladium(II) chloride under relatively mild conditions.

Alkylation↗

DNA-bound transcription factor complexes analysed by mass-spectrometry: binding of novel proteins to the human c-fos SRE and related sequences.

Transcription factors control eukaryotic polymerase II function by influencing the recruitment of multiprotein complexes to promoters and their subsequent integrated function. The complexity of the functional 'transcriptosome' has necessitated biochemical fractionation and subsequent protein sequencing on a grand scale to identify individual components. As a consequence, much is now known of the basal transcription complex. In contrast, less is known about the complexes formed at distal promoter elements. The c-fos SRE, for example, is known to bind Serum Response Factor (SRF) and ternary complex factors such as Elk-1. Their interaction with other factors at the SRE is implied but, to date, none have been identified. Here we describe the use of mass-spectrometric sequencing to identify six proteins, SRF, Elk-1 and four novel proteins, captured on SRE duplexes linked to magnetic beads. This approach is generally applicable to the characterisation of nucleic acid-bound protein complexes and the post-translational modification of their components.

Amino Acid Sequence↗

Metallic cough and pyogenic liver abscess.

The curious symptom of a metallic cough in association with a pyogenic hepatic abscess should heighten awareness of a fistula. We describe a 78-year-old female with severe diverticular disease, on long-term steroid treatment for polymyalgia rheumatica. She developed a pyogenic liver abscess, treated initially by antimicrobial therapy, and subsequently drained by ultrasound and computed tomography-guided percutaneous transhepatic pigtail catheterization. This was complicated by a fistulous communication between the abscess cavity and the bronchus, confirmed by radiology. After repeated attempts at drainage and antimicrobial therapy the abscess cavity, including the hepatobronchial fistula, resolved.

Aged↗

Identification of proteins from one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis using electrospray quadrupole-time-of-flight tandem mass spectrometry.

The potential of electrospray tandem mass spectrometry using a quadrupole-time-of-flight tandem mass spectrometer was evaluated for the identification of two unknown proteins from one-dimensional polyacrylamide gel electrophoresis (1-D-PAGE). Two proteins from cellular cultures of mammary epithelia were purified by 1D-PAGE. Their identification was achieved using peptide sequence tags generated by LC/Q-TOF-MS/MS, whereas MALDI-TOF mass mapping failed for these proteins obtained from simple 1D-PAGE separation.

Amino Acid Sequence↗

Cp50 of propofol with and without nitrous oxide 67%.

The target concentration of propofol required to prevent response to surgical incision was determined in 60 unpremedicated ASA I or II patients, who breathed either oxygen-enriched air or nitrous oxide 67% in oxygen. Propofol was infused using a target-controlled infusion system incorporating the standard 'Diprifusor' pharmacokinetic model, with the target concentration for each patient decided by up/down sequential allocation. Presence or absence of movement in response to a groin incision was determined by the surgeon. The calculated blood concentration at which 50% of patients responded (Cp50calc), determined by probit analysis, was 6.8 micrograms ml-1 for patients who breathed oxygen-enriched air and 4.9 micrograms ml-1 for those who breathed nitrous oxide 67% in oxygen.

Adolescent↗

Drinking and driving: explaining beverage-specific risks.

OBJECTIVE: This study tested whether the association of beer drinking with drinking and driving is due to cultural norms or is an artifact arising from the demographic profile of beer drinkers (young and male), the drinking patterns of this subpopulation (frequent and heavy), and the venues in which they prefer to drink (bars and restaurants). METHOD: Telephone survey data from six U.S. communities were used to establish the demographic characteristics of drinkers, their consumption patterns, beverage preferences, preferred drinking venues and self-reported drinking and driving rates. The survey completion rate was 64.6%. A total sample of 5,231 drinkers was divided into test and validity samples. After deletion of cases with missing data, the test sample included 2,275 drinkers, of whom 985 had driven after drinking. RESULTS: Controlling for a broad set of covariates, the analyses showed that frequent consumers were more likely to drink outside the home, preferred beer and spirits to wine, and were more likely than others to drink and drive. Beverage preferences were not directly associated with drinking and driving. Beer drinkers, however, were from the subpopulation most likely to drink and drive: heavier drinking younger men, who prefer to drink at bars and restaurants. CONCLUSIONS: These results suggest that the association of beer consumption with drinking-driving arises from the circumstances in which the subpopulation of beer drinkers more commonly find themselves (as a result of their efforts to maximize, within economic constraints, the social and amenity value of drinking), as opposed to any culturally induced disposition beer drinkers may have to drink and drive.

Age Factors↗

Beta-catenin mutations are specific for colorectal carcinomas with microsatellite instability but occur in endometrial carcinomas irrespective of mutator pathway.

Some colorectal tumors with wild-type adenomatous polyposis coli gene have activating mutations in beta-catenin (encoded by CTNNB1) that result in decreased phosphorylation by GSK-3beta and increased signaling through the Tcf/Lef transcription factors. To investigate the relationship between CTNNB1 mutations and underlying pathways of genomic instability, we examined 80 colorectal cancers stratified by the presence or absence of microsatellite instability (MSI). CTNNB1 mutations were identified in 13 (25%) of 53 cancers with high frequency MSI (MSI-H), including 12 point mutations at exon 3 phosphorylation sites (codons 41 and 45) and one deletion of the entire exon 3 degradation box. No CTNNB1 mutations were identified in 27 microsatellite stable or low frequency MSI (MSI-L) colorectal cancers (P < 0.01). In contrast, CTNNB1 mutations were identified in 3 of 9 (33%) MSI-H and 10 of 20 (50%) MSS/MSI-L endometrial carcinomas, suggesting a more generalized involvement in these tumors. Only six (46%) of the endometrial carcinoma CTNNB1 mutations occurred at residues directly phosphorylated by GSK-3beta, and only one of these was at either codon 41 or 45. All point mutations in MSI-H cancers were transitions, whereas 64% of those in MSS/MSI-L cancers were transversions (P < 0.01). The differences in the mutation profiles suggest that there may be molecular fingerprints of CTNNB1 mutations, determined by biological factors related to both tumor type and underlying pathways of genomic instability.

Adenocarcinoma↗

Intestinal ulceration, obstruction, and haemorrhage in congenital syphilis.

Intestinal obstruction and bleeding are uncommon complications of congenital syphilis (CS). A VDRL-positive infant developed incomplete intestinal obstruction and rectal bleeding. Despite conservative management, his symptoms continued. At laparotomy, terminal ileal inflammation and stenosis were demonstrated. He underwent ileal resection and primary end-to-end anastomosis with resolution of his symptoms. Histopathological examination demonstrated heavy plasmacytic infiltration of the lamina propria and submucosa with ulceration of the mucosa, consistent with syphilitic ileitis. This report documents for the first time bleeding from ileal ulcers associated with intestinal obstruction in CS and highlights an unusual presentation of the disease.

Gastrointestinal Hemorrhage↗

Is an organic/functional distinction psychologically meaningful in patients with dysphonia?

Dysphonia (hoarseness) is a common clinical condition and, if persistent, patients are referred to otolaryngology clinics for clinical examination. During the examination, a clinical distinction is often made among three types of patients: (1) those with a clear organic basis for dysphonia (cancer, vocal cord palsy): (2) those with some degree of organic pathology; and (3) those with an apparently functional etiology. Functional patients are often characterized as having a psychogenic disorder. This study assessed the psychological validity of the functional category in 204 out-patients (aged 17 to 87 years) with persistent hoarseness of types (2) and (3). Following clinical examination, a consultant otolaryngologist categorized patients as having functional or organic etiology. Subjects were then compared on measures of personality and psychological distress. Dysphonic subjects showed marked psychological distress compared with norms, and reported significantly more previous psychosomatic symptoms than norms, but there were no differences in personality or psychological distress between organic and functional subgroups of dysphonics.

Adolescent↗

Immunohistochemistry for hMLH1 and hMSH2: a practical test for DNA mismatch repair-deficient tumors.

Inactivation of deoxyribonucleic acid (DNA) mismatch repair genes, most commonly human mutL homologue 1 (hMLH1) or human mutS homologue 2 (hMSH2), is a recently described alternate pathway in cancer development and progression. The resulting genetic instability is characterized by widespread somatic mutations in tumor DNA, and is termed high-frequency microsatellite instability (MSI-H). Although described in a variety of tumors, mismatch repair deficiency has been studied predominantly in colorectal carcinoma. Most MSI-H colorectal carcinomas are sporadic, but some occur in patients with hereditary nonpolyposis colorectal cancer (HNPCC), and are associated with germline mutations in mismatch repair genes. Until now, the identification of MSI-H cancers has required molecular testing. To evaluate the role of immunohistochemistry as a new screening tool for mismatch repair-deficient neoplasms, the authors studied the expression of hMLH1 and hMSH2, using commercially available monoclonal antibodies, in 72 formalin-fixed, paraffin-embedded tumors that had been tested previously for microsatellite instability. They compared immunohistochemical patterns of 38 MSI-H neoplasms, including 16 cases from HNPCC patients with known germline mutations in hMLH1 or hMSH2, with 34 neoplasms that did not show microsatellite instability. Thirty-seven of 38 MSI-H neoplasms were predicted to have a mismatch repair gene defect, as demonstrated by the absence of hMLH1 and/or hMSH2 expression. This included correspondence with all 16 cases with germline mutations. All 34 microsatellite-stable cancers had intact staining with both antibodies. These findings clearly demonstrate that immunohistochemistry can discriminate accurately between MSI-H and microsatellite-stable tumors, providing a practical new technique with important clinical and research applications.

Adaptor Proteins, Signal Transducing↗

A randomized phase-II study of BB-10010 (macrophage inflammatory protein- 1alpha) in patients with advanced breast cancer receiving 5-fluorouracil, adriamycin, and cyclophosphamide chemotherapy.

BB-10010 is a variant of the human form of macrophage inflammatory protein-1alpha (MIP-1alpha), which has been shown in mice to block the entry of hematopoietic stem cells into S-phase and to increase their self-renewal capacity during recovery from cytotoxic damage. Its use may constitute a novel approach for protecting the quality of the stem cell population and its capacity to regenerate after periods of cytotoxic treatment. Thirty patients with locally advanced or metastatic breast cancer were entered into the first randomized, parallel group controlled phase II study. This was designed to evaluate the potential myeloprotective effects of a 7-day regimen of BB-10010 administered to patients receiving six cycles of 5-fluorouracil (5-FU), adriamycin, and cyclophosphamide (FAC) chemotherapy. Patients were randomized, 10 receiving 100 microgram/kg BB-10010, 11 receiving 30 microgram/kg BB-10010, and nine control patients receiving no BB-10010. BB-10010 was well-tolerated in all patients with no severe adverse events related to the drug. Episodes of febrile neutropenia complicated only 4% of the treatment cycles and there was no difference in incidence between the treated and nontreated groups. Studies to assess the generation of progenitor cells in long-term bone marrow cultures were performed immediately preceding chemotherapy and at the end of six dosing cycles in 18 patients. Circulating neutrophils, platelets, CD 34(+) cells, and granulocyte/macrophage colony-forming cell (GM-CFC) levels were determined at serial time points in cycles 1, 3, and 6. The results showed similar hemoglobin and platelet kinetics in all three groups. On completion of the six treatment cycles, the average pretreatment neutrophil levels were reduced from 5.3 to 1.7 x 10(9)/L in the control patients and from 4.3 to 1.9 and 4.5 to 2.5 x 10(9)/L in the 30/100 microgram/kg BB-10010 groups, respectively. Relative to their pretreatment values, 50% of the patients receiving BB-10010 completed the treatment with neutrophil values significantly higher than any of the controls (P = .02). Mobilization of GM-CFC was enhanced by BB-10010 with an additional fivefold increase over that generated by chemotherapy alone, giving a maximal 25-fold increase over pretreatment values. Bone marrow progenitor assays before and after this standard regimen of chemotherapy indicated little long-term cumulative impairment to recovery from chemotherapy. Despite the limited cumulative damage to the bone marrow, which may have minimized the protective value of BB-10010 during this regimen of chemotherapy, better recovery of neutrophils in the later treatment cycles with BB-10010 was indicated in a number of patients.

Adult↗

Clinical effects of human macrophage inflammatory protein-1 alpha MIP-1 alpha (LD78) administration to humans: a phase I study in cancer patients and normal healthy volunteers with the genetically engineered variant, BB-10010.

BB-10010 is a genetically engineered variant of human macrophage inflammatory protein-1 alpha (hMIP-1 alpha) with improved pharmaceutical formulation properties. Although initially described as a pro-inflammatory cytokine, it is now recognised that hMIP-1 alpha has additional effects on haemopoietic stem cell cycling and on human immunodeficiency virus uptake by macrophages. In view of the potential clinical utility of the molecule, we have embarked on a clinical trials programme to evaluate the safety, tolerability and haematological effects of BB-10010. We now report the results of two phase I clinical studies in which 49 subjects (9 patients with advanced breast carcinoma and 40 normal healthy volunteers) received escalating doses of BB-10010, from 0.1 to 300 micrograms/kg using the subcutaneous (s.c.) or intravenous route (i.v.) of administration. Treatment was associated with a dose-related increase in monocyte count which peaked at 200% of steady-state levels and was preceded by an acute, short-lived, monocytopenia, 50-100% of baseline. no measurable effects were noted on other leucocyte subsets or on circulating progenitor cell numbers. In all cases, BB-10010 was extremely well tolerated with no significant toxicity observed at any dose level and a maximum tolerated dose was not defined. Pharmacokinetic analysis revealed that serum concentrations of BB-10010 were detectable using doses of > or = 10 micrograms/kg i.v. or > or = 30 micrograms/kg s.c., and that a single s.c. injection resulted in sustained plasma levels over a 24 h period. These preliminary studies have confirmed the safety and tolerability of BB-10010 using a dose range up to 300 micrograms/kg. Further clinical studies are ongoing to determine the biological effects and to investigate the potential myeloprotective properties using a variable dose range and schedule of BB-10010 in combination with cytotoxic chemotherapy.

Adult↗

Production of interleukin 13 by alveolar macrophages from normal and fibrotic lung.

Human interleukin 13 (IL-13) is a cytokine that has a profound effect on primary immune cells by inducing immunoglobulin production, proliferation of B cells, and the differentiation of cells of the monocytic lineage. IL-13 can inhibit the production of inflammatory cytokines by both macrophages and monocytes. Previously, IL-13 expression has been reported only in cells of the T-cell lineage and the mast cell line HMC-1. We now report the presence of IL-13 mRNA and protein in human alveolar macrophages (AMs) analyzed by the reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunoabsorbent assay (ELISA), respectively, and IL-13 protein in bronchoalveolar lavage fluid (BALF) of subjects with pulmonary fibrosis. We have investigated 13 patients from 49 to 75 yr of age with forms of pulmonary fibrosis, and eight healthy volunteers from 24 to 61 yr of age. Their AMs were obtained by bronchoalveolar lavage (BAL) and purified by adherence. The proportion of BAL purified AMs expressing IL-13 mRNA was increased in those subjects with fibrotic lung disease, in comparison with those from control subjects (11 of 13 versus 2 of 8, P < 0.01). IL-13 protein was detectable in the BALF of 8 of 13 patients with pulmonary fibrosis, but in none of the control subjects. AMs of four subjects with systemic sclerosis were cultured and IL-13 protein was increased in the culture supernatants when compared to the control subjects, although this did not reach significance. These findings show that IL-13 mRNA is not only a product of T cells, but is also expressed in both normal AMs and those from subjects with pulmonary fibrosis, and that at least some of the IL-13 mRNA is translated into protein and secreted in subjects with pulmonary fibrosis. We hypothesize that IL-13 may be expressed by normal human AMs as part of the homeostatic control process but its production may be increased in the presence of inflammatory lung disease.

Adult↗