Search PubMed⌕ Search

Biomedical subjects

C James

Publications and source records attributed to C James.

At least 37 records · Page 2Linked to original sources
PubMed2001

Implementation of Web-based interaction technology to improve the quality of a city's health care.

In the clinic, one method for improving the interaction is to ask patients to systematically report their health status, give them standard advice based on their responses, and ask them to discuss this advice with a health practitioner. In the school system, this approach provides aggregate information for targeting programs to meet student needs. In the workplace, this health assessment and personal feedback approach may be offered to employees to improve health care and lower health care costs. But why stop at the door of the clinic, school, or workplace when Internet technology can extend to an entire community the benefits of health assessment and feedback?

Adolescent↗
PubMed2001

Adjusting for patient characteristics when analyzing reports from patients about hospital care.

OBJECTIVES: To determine which patient characteristics are associated with reports and ratings of hospital care, and to evaluate how adjusting reports and ratings for hospital differences in such variables affects comparisons among hospitals. DESIGN: A telephone survey of a sample of patients hospitalized in 22 hospitals in a single city and a statewide mail survey of hospitalized patients. MEASURES: The surveys assessed: respect for patients' preferences, coordination of care, information exchange between patient and providers, physical care, emotional support, involvement of family and friends, and transition and continuity. The surveys also asked patients to rate their doctors, nurses, and other hospital staff. RESULTS: The variables with the strongest and most consistent associations with patient-reported problems were age and reported health status. Patient gender and education level also sometimes predicted reports and/or ratings. Models including these variables explained only between 3% and 8% of the variation in reports and ratings. CONCLUSIONS: The impact of adjusting for patient characteristics on hospital rankings was small, although a larger impact would be expected when comparing hospitals with more variability in types of patients. Nevertheless, we recommend adjusting at least for the most important predictors, such as age and health status. Such adjustment helps alleviate concerns about bias. It also may be useful to present data for certain groups of patients (ie, medical, surgical, obstetric) separately to facilitate interpretation and quality improvement efforts.

Age Factors↗
PubMed2001

Gastric acid secretory response in Helicobacter pylori-positive patients with duodenal ulcer disease.

BACKGROUND: Patients with duodenal ulcer (DU) have an increased parietal cell mass and sensitivity to secretagogues, with increased acid output. AIM: To determine the effect of Helicobacter pylori eradication on parietal cell sensitivity and gastric acid secretion. SUBJECTS AND METHODS: Twenty-five H pylori-positive DU patients and 18 H pylori-negative healthy volunteers were studied. Serum H pylori immunoglobulin G, basal acid output and acid secretory response to graded doses of pentagastrin were determined before and after treatment, at six months and at one year. Subjects were randomly assigned to ranitidine or sucralfate treatment for six weeks, and all DU patients received bismuth subsalicylate, metronidazole and tetracycline for the first two weeks. RESULTS: H pylori was eradicated in 66% of patients receiving sucralfate and 92% receiving ranitidine. Compared with healthy volunteers, DU patients demonstrated a 2.7-fold greater basal acid output, a 1.3-fold greater peak acid output, significantly higher acid output for each dose of pentagastrin and a 1.38-fold increase in the area under the pentagastrin dose acid response curve. Cure of H pylori, irrespective of ulcer healing regimen, resulted in a gradual decrease in acid secretory capacity with basal acid output, peak acid output and area under the pentagastrin dose acid response curve returning to healthy volunteer levels by one year. No demonstrable differences were observed in parietal cell sensitivity in all subjects before or after treatment. These data suggest that disturbances in acid secretion in H pylori-positive DU patients are not due to an increased parietal cell sensitivity to pentagastrin but rather due to an increased parietal cell mass with increased capacity to secrete acid, which gradually resolves following cure.

Adult↗
PubMed2000

Search for direct CP violation in nonleptonic decays of charged Xi and lambda hyperons

A search for direct CP violation in the nonleptonic decays of hyperons has been performed. In comparing the product of the decay parameters, alpha(Xi)alpha(Lambda), in terms of an asymmetry parameter, A(XiLambda), between hyperons and antihyperons in the charged Xi-->Lambdapi and Lambda-->ppi decay sequence, we found no evidence of direct CP violation. The parameter A(XiLambda) was measured to be 0.012+/-0.014.

Journal Article↗
PubMed2000

A randomized trial measuring fecal blood loss after treatment with rofecoxib, ibuprofen, or placebo in healthy subjects.

PURPOSE: Gastrointestinal microbleeding, as assessed by the measurement of (51)chromium-labeled red blood cells, is a marker of the mucosal injury associated with the use of nonsteroidal anti-inflammatory drugs. This study tested the hypotheses that cyclooxygenase-2 specific inhibition with rofecoxib would cause less fecal blood loss than a therapeutic dose of ibuprofen and would be equivalent to placebo. SUBJECTS AND METHODS: In this randomized, double-blind group study, gastrointestinal blood loss was assessed by measurement of fecal (51)chromium radioactivity during a 1-week placebo baseline period and during 4 weeks of treatment with rofecoxib (25 mg or 50 mg once daily), ibuprofen (800 mg three times daily), or placebo in 67 healthy subjects. Gastrointestinal blood loss during treatment weeks 2 to 4 (versus the baseline period) was expressed as the geometric mean ratio of fecal radioactivity in weeks 2 to 4 compared with baseline. RESULTS: Ibuprofen caused significantly (P <0.001) greater gastrointestinal blood loss (geometric mean ratio of 5.2, 95% confidence interval [CI]: 4.2 to 6.3) than the 25-mg dose of rofecoxib (2.6, 95% CI: 2.2 to 3.1), the 50-mg dose of rofecoxib (2.6, 95% CI: 2.2 to 3.0), or placebo (2.1, 95% CI: 1.8 to 2.5). In contrast, gastrointestinal blood loss with both doses of rofecoxib were equivalent to placebo by a predetermined clinical similarity bound. CONCLUSIONS: In healthy subjects, treatment with rofecoxib, at 2 to 4 times the doses that are currently recommended for the treatment of patients with osteoarthritis, produced significantly less fecal blood loss than a therapeutic dose of ibuprofen and was equivalent to placebo.

Adult↗
PubMed2000

Sensitivity to myc-induced apoptosis is retained in spontaneous and transplanted lymphomas of CD2-mycER mice.

To study the effects of the Myc oncoprotein in a regulatable in vivo system, we generated lines of transgenic mice in which a tamoxifen inducible Myc fusion protein (c-mycER) is expressed under the control of the CD2 locus control region. Activation of the Myc oncoprotein resulted in both proliferation and apoptosis in vivo. Lines with a high transgene copy number developed spontaneous lymphomas at low frequency, but the tumour incidence was significantly increased with tamoxifen treatment. Surprisingly, we found that cellular sensitivity to Myc-induced apoptosis was retained in tumours from these mice and in most lymphoma cell lines, even when null for p53. Resistance to Myc-induced apoptosis could be conferred on these cells by co-expression of Bcl-2. However, acquired resistance is clearly not an obligatory progression event as sensitivity to apoptosis was retained in transplanted tumours in athymic mice. In conclusion, lymphomas arising in CD2-mycER mice retain the capacity to undergo apoptosis in response to Myc activation and show no phenotypic evidence of the presence of an active dominant inhibitor.

Animals↗
PubMed2000

LC-MS-MS determination of exemestane in human plasma with heated nebulizer interface following solid-phase extraction in the 96 well plate format.

A sensitive, specific and rapid analytical method for the quantitation of exemestane (EXE) in human plasma has been developed. EXE, 6-methylen-androsta-1,4-diene-3,17-dione, is an orally active irreversible steroidal aromatase inhibitor used for the therapy of metastatic postmenopausal breast cancer, with estrogen-dependent pathological conditions. The method involves extraction of EXE from human plasma by solid phase extraction using C2 endcapped sorbent in the 96 well plate format (50 mg/2 ml). After conditioning of the sorbent with 1 ml of acetonitrile (x2) the plates were rinsed with 1 ml of water (x2). The prepared samples (0.5 ml plasma, spiked with [13C3] EXE as internal standard (IS) and diluted with 0.5 ml water) were loaded and drawn through the plate with a minimum of vacuum. The plates were then washed with 1 ml acetonitrile:water (10:90) followed by a drying step for 30 min at full vacuum. Elution was by 0.15 ml of 0.1% trifluoracetic acid in acetonitrile (x2) under a minimum of vacuum. Aliquots of 80 microl were finally injected into the LC-MS-MS system. A Zorbax SB C8 column (4.6 x 150 mm, 5 microm) was used to perform the chromatographic separation; the mobile phase was 100% acetonitrile. MS detection used the heated nebulizer interface, with multiple reaction monitoring (MRM) (297-->121 m/z for EXE and 300-->123 m/z for IS) operated in positive ion mode. A weighed linear regression analysis (weighing factor 1/x2) was used to calculate EXE concentration in standard and unknown samples. The method was fully validated in the concentration range 0.05-25 ng ml(-1).

Androstadienes↗
PubMed2000

Determination of MAG-camptothecin, a new polymer-bound camptothecin derivative, and free camptothecin in dog plasma by HPLC with fluorimetric detection.

A high throughput. selective and sensitive high-performance liquid chromatographic (HPLC) method for the determination of a water-soluble polymer-bound Camptothecin conjugate (MAG-CPT) and Camptothecin (CPT) in dog plasma has been developed and validated. The method involved the analysis of free and total CPT (free + polymer-bound). Free CPT (intact lactone plus carboxylate) was extracted from acidified plasma using Oasis SPE material in 96-well plates. For the assay of the total CPT, plasma proteins were first precipitated with methanol in a 96-well plate containing a 10-microm melt blown polypropylene membrane. The methanolic supernatant was separated and collected into a second 96-well plate by simply applying vacuum to the plate. After hydrolysis at pH 9.8 for 18 h and re-acidification, samples were injected directly from the collection plate onto the HPLC system. MAG-CPT concentration was then calculated by subtraction of free from total CPT. The LLOQs of the method were 1.17 ng/ml for free CPT and 103.10 ng/ml (as CPT equivalent) for MAG-CPT using 0.1 and 0.05 ml of plasma, respectively. Linearity, precision, accuracy and recovery of the method were evaluated. The stability of MAG-CPT in plasma alone and after its stabilisation was carefully evaluated. No interference from blank dog, mouse and human plasma was observed. The suitability of the method for in vivo samples was assessed by the analysis of samples obtained from dogs that had received a single and 5-day repeated dose of MAG-CPT.

Acrylamides↗
PubMed2000

A randomized controlled trial to assess alendronate-associated injury of the upper gastrointestinal tract.

BACKGROUND: Aminobisphosphonates are recommended for postmenopausal osteoporosis but have been associated with injury to the upper gastrointestinal tract. AIM: To conduct a randomized controlled trial, to assess the endoscopic damage caused by alendronate and its effect on gastric mucosal prostaglandin synthesis. METHODS: Seventy-six healthy volunteers age 40-60 years, with normal baseline endoscopy were randomly assigned to treatment with: (A) ASA 650 mg q. d.s.; (B) alendronate 10 mg o.d.; or (C) placebo o.d. for 14 days. Mucosal injury scores on day 14 of treatment were reported by a blinded endoscopist. Gastric biopsies were analysed for prostaglandin E2 (PGE2) concentration by radioimmunoassay. RESULTS: Oesophageal injury did not differ among treatment groups. Gastric ulcers developed in five out of 26 subjects given ASA, two out of 25 given alendronate, and none of 25 given placebo. The mucosal damage scores for the alendronate group exceeded those for the placebo group in the gastric body but not at other sites. Injury scores for ASA exceeded those for placebo in the duodenum, antrum, body, and fundus. The mean change in log10[PGE2] (ng/mg protein) was - 0.07 for placebo, - 0.80 for ASA, and + 0.62 for alendronate (differences not significant). CONCLUSIONS: Alendronate is associated with injury and ulceration of the gastric mucosa. This effect was not associated with any significant change in gastric mucosal PGE2 levels.

Adult↗
PubMed2000

Epitope analysis of the human thyrotropin (TSH) receptor using monoclonal antibodies.

A panel of thyrotropin (TSH) receptor (TSHR) monoclonal antibodies (mAbs), produced using highly purified Chinese hamster ovary (CHO) cell-produced TSHR, has been used to study TSHR structure. All 41 mAbs recognized full-length TSHR containing complex carbohydrate (120 kDa), and 40 mAbs recognized full-length precursor-containing high mannose sugars (100 kDa). The mAbs also recognized TSHR cleavage products with three types of reactivity: type 1 mAbs reacting with bands at 70 kDa and 58 kDa, type 2 with bands at 70 kDa and 52 kDa, and type 3 with bands at 52 kDa and 40 kDa. Deglycosylation studies showed that the 70-kDa and 58-kDa bands contained complex carbohydrate, whereas the 52-kDa and 40-kDa bands were unglycosylated. These results are consistent with TSHR cleavage occurring at two sites. Cleavage at both sites gives rise to glycosylated A subunit (58 kDa) corresponding to the extracellular domain of the receptor and nonglycosylated B subunit (40 kDa) corresponding to the C-terminal transmembrane domain. Cleavage only at site 1 gives rise to the 58-kDa A subunit and a large B subunit (52 kDa). Cleavage only at site 2 gives rise to a large A subunit (70 kDa) and the B subunit (40 kDa). Four of the mAbs inhibited 125I-labeled TSH binding to solubilized full-length TSHR. TSH binding was inhibited by (a) two type 3 mAbs reactive with the N-terminal region of the B subunit (epitopes between amino acids 381 and 385 and between 380 and 418, respectively) and (b) two type 2 mAbs reactive with epitopes on the A subunit (between amino acids 246 and 260). These results together with previous studies on the direct binding of TSH to the TSHR A subunit suggest that at least two distinct regions of the TSHR sequence, including one region on the A subunit and one region on the B subunit, fold together to form part of a complex TSH binding site.

Amino Acid Sequence↗
PubMed1999

Caenorhabditis elegans inhibitor of apoptosis protein (IAP) homologue BIR-1 plays a conserved role in cytokinesis.

BACKGROUND: Inhibitor of apoptosis proteins (IAPs) suppress apoptotic cell death in several model systems and are highly conserved between insects and mammals. All IAPs contain at least one copy of the approximately 70 amino-acid baculovirus IAP repeat (BIR), and this domain is essential for the anti-apoptotic activity of the IAPs. Both the marked structural diversity of IAPs and the identification of BIR-containing proteins (BIRPs) in yeast, however, have led to the suggestion that BIRPs might play roles in other, as yet unidentified, cellular processes besides apoptosis. Survivin, a human BIRP, is upregulated 40-fold at G2-M phase and binds to mitotic spindles, although its role at the spindle is still unclear. RESULTS: We have identified and characterised two Caenorhabditis elegans BIRPs,BIR-1 and BIR-2; these proteins are the only BIRPs in C. elegans. The bir-1 gene is highly expressed during embryogenesis with detectable expression throughout other stages of development; bir-2 expression is detectable only in adults and embryos. Overexpression of bir-1 was unable to inhibit developmentally occurring cell death in C. elegans and inhibition of bir-1 expression did not increase cell death. Instead, embryos lacking bir-1 were unable to complete cytokinesis and they became multinucleate. This cytokinesis defect could be partially suppressed by transgenic expression of survivin, the mammalian BIRP most structurally related to BIR-1, suggesting a conserved role for BIRPs in the regulation of cytokinesis. CONCLUSIONS: BIR-1, a C. elegans BIRP, is probably not involved in the general regulation of apoptosis but is required for embryonic cytokinesis. We suggest that BIRPs may regulate cytoskeletal changes in diverse biological processes including cytokinesis and apoptosis.

Amino Acid Sequence↗
PubMed1999

Histological study of hair follicles treated with a 3-msec pulsed ruby laser.

BACKGROUND AND OBJECTIVE: Ruby laser energy at 694 mn is moderately absorbed by melanin and minimally absorbed by other skin chromophores. This property and its depth of penetration into dermis permit absorption into pigmented hair follicles, thus making it suited to photothermolysis of these appendages. Clinical reports of the efficacy of such lasers for removal of unwanted hair are emerging in large numbers, but scientific data regarding the exact mechanism of action is still lacking. This study aims to evaluate and define further the histological responses of hair follicles to 3-msec pulsed ruby laser light. STUDY DESIGN/MATERIALS AND METHODS: Twenty-four patients with brown or black axillary or groin hair were treated with a 3-msec ruby laser at fluences from 10 to 40 J/cm2 on one, two, or three occasions. Biopsies were taken at various intervals from immediately to 8 weeks after treatments. Biopsies were fixed and stained with either nitroblue tetrazolium chloride or hematoxylin and eosin for histological examination. RESULTS: One treatment induced changes typical of catagen followed by telogen at all fluences. The papillae always remained viable. Two and three treatments resulted in atypical telogen, with infundibular dilatation and plugging, and marked proliferation of the stem outer sheath. New anagen follicles were evident even after three treatments at 12- and then 8-week intervals and were biopsied 6 weeks later, but there were no hairs extending to or through the epidermis. CONCLUSION: There was no evidence of permanent follicle death after one ruby laser treatment. However, despite evidence of persistence of follicular elements after two and three treatments, it is possible that laser-induced damage to the isthmus and upper stem may interfere with the interaction between dermal and epidermal germinative cells, thus inhibiting or altering the normal hair cycle.

Biopsy↗
PubMed1999

Different origin of auditory and phonological processing problems in children with language impairment: evidence from a twin study.

This study investigated the heritability of auditory processing impairment, as assessed by Tallal's Auditory Repetition Test (ART). The sample consisted of 37 same-sex twin pairs who had previously been selected because one or both twins met criteria for language impairment (LI) and 104 same-sex twin pairs in the same age range (7 to 13 years) from the general population. These samples yielded 55 children who met criteria for LI, who were compared with 76 children whose language was normal for their age (LN group). We replicated earlier work showing that group LI is impaired relative to group LN on ART. However, there was no evidence of a heritable influence on ART scores: Correlations between twins and their co-twins were reasonably high for both MZ and DZ twins, suggesting that performance is more influenced by shared environment than genetic factors. Analyses of extreme scores gave a similar picture of nonsignificant group heritability. In contrast, a test of phonological short-term memory, the Children's Nonword Repetition Test (CNRep), gave high estimates of group heritability. In general, CNRep was a better predictor of low language test scores than ART, but ART did make a significant independent contribution in accounting for variance in a test of grammatical understanding.

Adolescent↗
PubMed1999

Non-uniformity of surface temperatures after microwave heating of poultry meat.

Microwave energy has the potential to raise the surface temperatures of meat rapidly for a short period of time sufficient to reduce bacterial numbers significantly without causing physical changes to the meat. Studies have investigated the ability of a standard domestic microwave oven (2450 MHz; IEC 1191 W), an experimental repeatable microwave cavity (2450 MHz; IEC 1139 W) and a number of shielding techniques to achieve uniform surface temperature distributions on pieces of poultry meat. In the domestic oven temperature differences of up to 60 and 80 degrees C were found between different points on the surface of the same sample after 30 s and 3 minutes of heating respectively. The use of a standard cavity and shielding resulted in a difference of less than 5 degrees C between the average surface temperature on the edge and middle of regular slabs of chicken after 30 s exposure. Results show that microwave heating, using 2450 MHz, is unlikely to produce consistently uniform enough surface temperatures on meat to reduce bacterial numbers without surface damage.

Animals↗
PubMed1999

Ex-vivo expansion of CFU-GM and BFU-E in unselected PBMC cultures with Flt3L is enhanced by autologous plasma.

BACKGROUND: Previous ex-vivo expansion studies in our laboratory, comparing unselected and CD34(+)-selected PBMC, have shown no advantage for CD34(+) cell selection, in terms of the expansion achieved. Our goal was to develop procedures for consistent generation of large numbers of hematopoietic progenitor and post-progenitor cells from unselected PBMC. METHODS: Unselected PBMC, collected from cancer patients undergoing apheresis prior to high-dose chemotherapy and autologous stem cell rescue, were expanded ex vivo in static cultures, without a stromal layer, in the presence of Flt3 ligand (Flt3L), a recombinant GM-CSF/IL-3 fusion protein (PIXY321), G-CSF and GM-CSF for 10 days. RESULTS: The addition of 2% autologous plasma to this cytokine combination enhanced expansion of total cell numbers (3.2 fold versus 1.9 fold; p < 0.01), colony-forming units granulocyte-macrophage (CFU-GM) (22.0 fold versus 8.1 fold, p < 0.01) and burst-forming units erythroid (BFU-E) (17.6 fold versus 7.0 fold, 0.01 < p < 0.02). The optimal seeding density for a given specimen was inversely related to the frequency of CD34(+) cells in the sample. CFU-GM expansion with the Flt3L-containing cytokine cocktail was equivalent to that obtained with IL-3, IL-6, G-CSF and SCF, whether or not the cultures were supplemented with autologous plasma. In plasma-free cultures, BFU-E expansion was significantly higher with IL-3, IL-6, G-CSF and SCF than with Flt3L, PIXY321, G-CSF and GM-CSF. In the presence of autologous plasma, however BFU-E expansion was higher in the Flt3L-containing media. In comparison studies, autologous plasma suppressed BFU-E expansion in SCF-containing cultures. Consistent with our colony assay results, dual-parameter flow cytometric analysis of the expanded cell population revealed that supplementation with autologous plasma yielded a significant increase in the numbers of myeloid progenitors in Flt3L-containing cultures. DISCUSSION: Unselected PBMC from cancer patients can be effectively expanded ex vivo in Flt3L, PIXY321, G-CSF and GM-CSF, supplemented with autologous plasma, yielding high numbers of myeloid and erythroid progenitors.

Antigens, CD34↗
PubMed1999

Altered growth and viral gene expression in human papillomavirus type 16-containing cancer cell lines treated with progesterone.

This study explores interactions between high-risk human papillomavirus type 16 (HPV-16) and the female sex hormone progesterone in the growth of tumor cells and viral oncogene expression. For both the cervical cancer cell line CaSki containing integrated HPV-16 DNA and the laryngeal carcinoma cell line HEp-2 transfected with HPV-16 DNA, prolonged progesterone treatment enhances their colony formation efficiency both on plastic surface and in soft agar. In contrast, progesterone has no effect on the HPV-negative cervical cancer cell line C-33A or the untransfected HEp-2 parental cells. Progesterone increases HPV-16 E6/E7 oncogene transcription in both HPV-16-containing cell lines. A detectable increase requires at least 3 days of treatment, and this delayed response may be due, at least in part, to increased stability of viral transcripts as determined by actinomycin D treatment. The progesterone antagonist RU 486 and nuclease-resistant oligomers containing HPV-16 progesterone response element are able to abrogate the enhancement by progesterone on cell growth and E6/E7 gene transcription. Taken together, these results support the notion that progesterone can be a cofactor in HPV-related malignancies.

Carcinoma, Squamous Cell↗