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D West

Publications and source records attributed to D West.

At least 37 records · Page 2Linked to original sources
PubMed2000

Amniotic gas values and acid-base status during acute maternal hyperoxemia and hypoxemia in the early fetal sheep.

OBJECTIVE: This study was undertaken to determine amniotic fluid gas values and acid-base balance during maternal hyperoxemia and hypoxemia in early pregnancy. STUDY DESIGN: Anesthetized sheep (n = 12) in early and mid pregnancy (0.3 to 0.5 gestation) were subjected to hyperoxemia followed by hypoxemia. Amniotic fluid PO (2), pH, PCO (2), bicarbonate concentration, and base excess were monitored continuously with a multiparameter Paratrend (Diametrics Medical Inc, St Paul, Minn) sensor and compared between 0.3 and 0.5 gestation. RESULTS: During maternal normoxemia all parameters were constant. At all gestational ages maternal hyperoxemia caused no changes apart from a rapid increase in amniotic fluid PO (2) (P <.001). Maternal hypoxemia led to a reduced amniotic fluid PO (2) (P <.001), whereas the PCO (2) and the bicarbonate concentration increased (P <.001). Changes in amniotic fluid gas values and acid-base balance were more pronounced at 0.3 gestation than at 0.5 gestation. Amniotic fluid Po(2) responded earlier to maternal hyperoxemia than to hypoxemia (9. 5 vs 14.3 minutes; P <.001). During hypoxemia maternal PaCO (2) changed faster than did amniotic fluid PCO (2) (P <.001). CONCLUSIONS: Acute maternal hypoxemia during early pregnancy was quickly reflected in amniotic fluid gas values and acid-base balance, whereas hyperoxygenation induced the quickest changes in amniotic fluid PO (2). The metabolic effects of maternal hyperoxemia and hypoxemia were also more pronounced during early pregnancy than at mid pregnancy.

Amniotic Fluid↗
PubMed1999

Suppression of apoptosis and induction of DNA synthesis in vitro by the phthalate plasticizers monoethylhexylphthalate (MEHP) and diisononylphthalate (DINP): a comparison of rat and human hepatocytes in vitro.

Diethylhexylphthalate (DEHP) and diisononylphthalate (DINP) are plasticizers with many important commercial, industrial and medical applications. However, both DEHP and DINP are rodent peroxisome proliferators (PPs), a class of compounds that cause rodent liver tumours associated with peroxisome proliferation, induction of hepatic DNA synthesis and the suppression of apoptosis. Despite these effects in the rodent, humans appear to be nonresponsive to the adverse effects of PPs. Previously, we have shown that the fibrate hypolipidaemic peroxisome proliferator, nafenopin, induced DNA synthesis and suppressed apoptosis in rat but not in human hepatocytes. In this work, we have examined species differences in the response of rat and human hepatocytes to DEHP and DINP in vitro. In rat hepatocytes in vitro, both DINP and MEHP (a principle metabolite of DEHP and the proximal peroxisome proliferator) caused a concentration-dependent induction of DNA synthesis and suppression of both spontaneous and transforming growth factor beta1 (TGFbeta1)-induced apoptosis. Similarly, both MEHP and DINP caused a concentration-dependent induction of peroxisomal beta-oxidation although the response to DINP was less robust. In contrast to the pleiotropic response noted in rat hepatocytes, neither DINP nor MEHP caused an induction of beta-oxidation, stimulation of DNA synthesis and suppression of apoptosis in human hepatocytes cultured from three separate donors. These data provide evidence for species differences in the hepatic response to the phthalates DEHP and DINP, confirming that human hepatocytes appear to be refractory to the hepatocarcinogenic effects of PPs first noted in rodents.

Animals↗
PubMed1999

Nosocomial candidaemias due to species other than Candida albicans in cancer patients. Aetiology, risk factors, and outcome of 45 episodes within 10 years in a single cancer institution.

Forty-five cases of fungaemia due non-albicans Candida spp. (NAC) in a single National Cancer Institution within 10 years were analysed for aetiology, risk factors and outcome. There had been 12 cases of fungaemia that were due to C. krusei, 14 due to C. parapsilosis, 7 due to C. (T.) glabrata, 6 to C. tropicalis, 2 to C. guillermondii, 2 to C. lusitaniae, 1 to C. stellatoidea, and 1 to C. rugosa. Comparison of 45 NAC fungaemia with 75 episodes of C. albicans fungaemia revealed differences only in two risk factors: previous empiric therapy with amphotericin B (16.0 vs 2.2%, P<0.01) appeared more frequently in cases of C. albicans fungaemia, and prior prophylaxis with fluconazole (8.9 vs 0%, P<0.02) was conversely more frequently observed with NAC. The incidence of other risk factors, such as underlying disease, chemotherapy, antibiotic prophylaxis or therapy, treatment with corticosteroids, catheter insertion, mucositis, cytotoxic chemotherapy, and neutropenia, was similar in both groups. There was no difference either in attributable or in overall mortality between NAC and C. albicans fungaemia in our cancer patients.

Adrenal Cortex Hormones↗
PubMed1999

Aetiology and outcome in 53 cases of native valve staphylococcal endocarditis.

Within the last 30 years the profile of infective endocarditis has altered considerably with regard to microbiological causation, clinical features, and natural history. A contributory factor has undoubtedly been the development of potent antibiotics and their sometimes indiscriminate use. The increase in intravenous drug abuse in urban centres, the use of immunosuppressive agents, and the use of prosthetic heart valves have also all contributed. Although cardiac surgery in the uninfected heart provides a perfect environment for infective endocarditis, the improved design of prosthetic valves and the enhanced long-term survival and decreased immediate operative risk, means that surgery is viewed as the best option in many cases. In a series of 53 cases of staphylococcal endocarditis from a national endocarditis survey, those risk factors which influenced outcome were analysed. Thirty out of 53 patients had predisposing heart disease. Mortality was 39.6%. Statistical analysis revealed that attributable mortality was significantly associated with skin infection, systemic embolisation, and inappropriate therapy. Interestingly, surgical treatment was associated with better outcome.

Anti-Bacterial Agents↗
PubMed1999

T cell-mediated and non-specific inflammatory mechanisms contribute to the skin pathology of HPV 16 E6E7 transgenic mice.

One of three lines of mice transgenic for the E6 and E7 genes of human papillomavirus type 16 (HPV16) expressed from an alphaA-crystallin promoter also expresses the transgene ectopically in the skin. This line, designated alphaACE6E7#19, develops skin disease from 3 months of age, characterised by epidermal hyperplasia and eventual skin loss. Administration of complete Freund's adjuvant (CFA) to alphaACE6E7#19 mice, but not to non-transgenic littermate controls, induced local epidermal hyperplasia which was histologically similar to the spontaneously arising skin pathology. Local application of 2,4-dinitrochlorobenzene (DNCB) to DNCB-sensitised alphaACE6E7#19 mice, but not DNCB-sensitised controls, also induced hyperplasia. Treatment with cyclosporin A (CsA) or systemic depletion of CD4+ cells significantly reduced the incidence of skin disease. These data suggest that local inflammation, and cytokines produced by T helper cells, contribute to the induction of hyperplastic skin disease in alphaACE6E7#19 mice. Spontaneous skin disease with similar histological appearance, frequency, age of onset and severity in alphaACE6E7#19 mice was observed in scid-/- alphaACE6E7#19 mice, despite immune paresis. Antigen-specific immune responses and T-cell cytokines are therefore not necessary for the induction of skin disease. We propose that epidermal hyperplasia associated with HPV16 E6 and E7 expression in skin is accelerated by local secretion of pro-inflammatory cytokines, whose production can be enhanced by activated CD4+ T cells.

Age Factors↗
PubMed1999

Documented fungal infections after prophylaxis or therapy with wide spectrum antibiotics: relationship between certain fungal pathogens and particular antimicrobials?

Antibiotics are known to be one of the major risk factors for fungal infection. We investigated whether there was a relationship between particular documented fungal infections and therapeutically or prophylactically administered antimicrobials in 105 patients with fungemia or histologically proven invasive aspergillosis or fusariosis. Out of 105 patients, 82.9% received antimicrobials affecting anaerobic microbial gut flora such as: imipenem, vancomycin, ceftazidime, metronidazole, clindamycin or ampicillin-sulbactam. In addition, 44.5% of patients had received prophylaxis with ofloxacin. 31.5% of Candida albicans fungemias occurred despite empiric therapy with amphotericin B and 21.1% during prophylaxis with azoles. The incidence of C. albicans infections (fungemias) was significantly higher (58.9% vs 33.7%, p<0.04) in patients receiving antibiotics not affecting anaerobic gut flora such as ofloxacin, an aminoglycoside or azithromycin. On the other hand, patients treated with third generation cephalosporins, carbapenems, glycopeptides, and broad spectrum penicillins were more likely to develop proven invasive Aspergillus spp. infection (27.9% vs 5.3%, p<0.001) in comparison to those treated with antimicrobials which preserve anaerobic gut flora.

Anti-Bacterial Agents↗
PubMed1999

Biliary imaging by spiral CT cholangiography--a retrospective analysis.

CT cholangiography employs spiral CT scanning after the administration of biliary contrast medium to generate three-dimensional images of the biliary tract. A retrospective review of 61 patients who had undergone CT cholangiography was performed to determine the technical efficacy and the clinical utility of the technique. The results of CT cholangiography were analysed retrospectively to determine technical success rate of the imaging procedure and to correlate imaging diagnosis with results of other diagnostic procedures and with clinical follow-up. 60 of the 61 examinations produced technically satisfactory images. 21 of these examinations showed bile duct abnormalities. (12 stones, 6 duct dilatation to papillary level, 2 post-operative strictures and 1 case of sclerosing cholangitis). The remaining 39 cases showed no bile duct abnormality. In 59 of the 60 cases, subsequent investigations and follow-up supported the CT cholangiographic diagnosis. CT cholangiography is a robust technique for imaging of the biliary tract and is a valuable addition to the battery of non-invasive biliary investigations.

Adolescent↗
PubMed1999

First paleoparasitological analysis of a midden in the Aleutian Islands (Alaska): results and limits.

Excavations on Buldir Island, Aleutian Islands, Alaska, have revealed the remains of several features dated between the 13th and 17th centuries A.D. Soil from an open-air workshop, represented by 2 excavated pits, and a structure built of whale bones were sampled for evidence of parasites and microfloristic remains. Two groups of helminth eggs (Diphyllobothrium and Ankylostomidae) were identified in samples from the open-air pits; microfloristical remains were found in all samples. This is the first paleoparasitological analysis conducted on an Aleutian midden.

Alaska↗
PubMed1998

Cancer surveillance in the U.S.: can we have a national system?

Cancer-related services are consuming ever-increasing health resources; along with this trend, health care costs are rising. As health care planners, researchers, and policymakers formulate strategies to meet this challenge, they are looking to cancer registries and the health information system built around them as collectors of the most extensive information regarding cancer treatment in the U.S. Currently, there are multiple programs collecting and reporting data regarding cancer incidence, morbidity, mortality, and survival. This report profiles cancer surveillance efforts in the U.S. and describes the National Coordinating Council for Cancer Surveillance, which was organized in 1995 to facilitate a collaborative approach among the organizations involved.

American Cancer Society↗
PubMed1998

Predictors of mortality in bacteremic cancer patients: retrospective analysis of 64 deaths occurring among 262 bacteremic episodes.

A total of 262 bacteremic episodes were observed in cancer patients in a single cancer institution during the last 7 years, and the recorded outcome was death in 65. The 65 patients who died (24.8% overall mortality) were divided retrospectively into two subgroups: (a) those who died of underlying disease with bacteremia (45 cases, 16.9% crude mortality) and (b) those who died of bacteremia (20 patients, 7.7% attributable mortality). Comparison of several risk factors in subgroups of patients who achieved a cure (197 cases) and of those who died and whose deaths were attributable (20 cases) revealed six risk factors that were associated with attributable mortality: (1) chemotherapy-induced neutropenia (P < 0.03), (2) Acinetobacter/Stenotrophomonas spp. bacteremias (P < 0.001), (3) liver failure (P < 0.001), (4) inappropriate therapy (P < 0.0001), (5) organ complications (P < 0.003) and (6) multiresistant organisms (P < 0.001). Enterococci and Pseudomonas aeruginosa, surprisingly, were found more frequently in those who died of an underlying disease with bacteremia than among patients who were cured (17.6% vs 7.6%, P < 0.05 and 29.1% vs 13.8%, P < 0.02). Those who died of infection had higher numbers of positive blood cultures, with 2.05 per episode, than did those who died of underlying disease with bacteremia (1.82) or those who were cured (1.51). Other risk factors, such as underlying disease, type of chemotherapy, origin of bacteremia, age, and catheters did not predict either overall or attributable mortality within the study group.

Adult↗
PubMed1998

Bacteremia and fungemia in pediatric versus adult cancer patients after chemotherapy: comparison of etiology, risk factors and outcome.

One hundred and eighteen (118) episodes of bacteremia and fungemia in children with cancer were compared to 401 episodes of bacteremia and fungemia in adults with cancer to assess differences in etiology, risk factors and outcome. A retrospective univariate analysis was performed of all episodes of bacteremia in national pediatric and adult cancer institutions appearing in 1990-1996. A total of 519 episodes of bacteremia were assessed and compared. Both cancer centers differed in prophylactic antibiotic policies. About 50% of adults but less than 5% of children received quinolone prophylaxis during neutropenia, even though the empiric antibiotic therapeutic strategy was similar. There were differences in etiology between the groups: staphylococci and Stenotrophomonas maltophilia were more frequently observed in children (P<0.01), Pseudomonas aeruginosa and Acinetobacter spp. in adults (P<0.05). Gram-positive bacteremia was surprisingly more commonly observed in adults (65.7% vs 33.3%, P<0.01). Mixed polymicrobial bacteremia occurred more commonly in adults (31.8% vs 7.6%, P<0.001) than in children. Analysis of risk factors did not observe differences in risk factors except for underlying disease (acute leukemia was more frequently observed in children -48.3% vs adults 33.7%, P<0.05 and prophylaxis: (prior prophylaxis with quinolones was more common in adults (47.5%) than in children (2.5%) P<0.0001). Overall and attributable mortality in pediatric bacteremia was significantly lower than in adults (P<0.03).

Adult↗
PubMed1998

Native valve staphylococcal endocarditis: etiology, risk factors and outcome in 53 cases.

Fifty-three cases of staphylococcal endocarditis from a national endocarditis survey were analyzed for risk factors and outcome. Thirty of 53 patients had predisposing heart disease (39.6% rheumatic fever) but only 3 were on dialysis, only 2 had central venous catheter, only 2 intravenous drug abuse but 7 had prior cardiosurgery. Mortality was 39.6%. In analyzing risk factors for death, attributable mortality was significantly associated with skin infections (P < 0.05), embolization (P < 0.02), inappropriate therapy (P < 0.005) either because of too short therapy (P < 0.003) or wrong antibiotic combination (P < 0.01). Surgical therapy was associated with better outcome (4.8% deaths vs. 31.2% survivors, P < 0.04).

Adult↗
PubMed1997

A new reporter cell line to monitor HIV infection and drug susceptibility in vitro.

Determination of HIV infectivity in vitro and its inhibition by antiretroviral drugs by monitoring reduction of production of p24 antigen is expensive and time consuming. Such assays also do not allow accurate quantitation of the number of infected cells over time. To develop a simple, rapid, and direct method for monitoring HIV infection, we generated a stable T-cell line (CEM) containing a plasmid encoding the green fluorescent protein (humanized S65T GFP) driven by the HIV-1 long terminal repeat. Clones were selected that displayed low constitutive background fluorescence, but a high level of GFP expression upon infection with HIV. HIV-1 infection induced a 100- to 1,000-fold increase in relative fluorescence of cells over 2 to 4 days as monitored by fluorescence microscopy, cytofluorimetry, and flow cytometry. Addition of inhibitors of reverse transcriptase, protease, and other targets at different multiplicities of infection permitted the accurate determination of drug susceptibility. This technique also permitted quantitation of infectivity of viral preparations by assessment of number of cells infected in the first round of infection. In conclusion, the CEM-GFP reporter cell line provides a simple, rapid, and direct method for monitoring HIV infectivity titers and antiretroviral drug susceptibility of syncytium-inducing strains.

Anti-HIV Agents↗
PubMed1997

Heparin-binding growth factor(s) derived from head and neck squamous cell carcinomas induce endothelial cell proliferations.

BACKGROUND: Tumor growth is dependent on the expansion and proliferation of the host vascular system into the primary neoplasm (angiogenesis). The development of an intact vascular system requires migration and proliferation of endothelial cells and assembly into microvessels. Previous studies in our laboratory demonstrated that head and neck squamous cell carcinomas (HNSCC) are angiogenic in vivo. To clarify the mechanism of HNSCC-induced angiogenesis, the present study sought to determine if HNSCCs produced endothelial cell mitogens in vitro. METHODS: Production of PGE-2, TGF-beta, FGF-2 (basic-FGF [fibroblast growth factor]), and vascular endothelial cell growth factor (VEGF) were quantitated by enzyme-linked immunoabsorbant assay (ELISA) in five HNSCC lines. Cell free supernatants of 5 HNSCC lines were tested in a nonradioactive proliferation assay using human umbilical vein endothelial cells (HUVECs). RESULTS: All lines demonstrated enhanced endothelial cell proliferation in a dose-dependent fashion. Fractionation of these supernatants by heparin column chromatography significantly reduced endothelial cell proliferation in the five lines tested (range, 31.7% to 46.23% reduction; mean, 38.14+/-6.02%). Pretreatment with antibody to VEGF but not transforming growth factor (TGF)-beta inhibited endothelial cell proliferation. CONCLUSIONS: These studies indicate HNSCCs produce factor(s) which stimulate endothelial cell proliferation and that VEGF may be involved in HNSCC-induced endothelial cell mitogenesis.

Carcinoma, Squamous Cell↗
PubMed1997

Development and characterization of an equine behaviour chamber and the effects of amitraz and detomidine on spontaneous locomotor activity.

This report describes the development of a behaviour chamber and the validation of the chamber of measure locomotor activity of a horse. Locomotor activity was detected by four Mini-beam sensors and recorded on a data logger every 5 min for 22 h. Horses were more active during daytime than in the evening, which was at least partially related to human activity in their surroundings. To validate the ability of the chambers to detect changes in activity, fentanyl citrate and xylazine HCl, agents well-characterized as a stimulant and a depressant, respectively, were administered to five horses. Fentanyl citrate (0.016 mg/kg) significantly increased locomotor activity which persisted for 30 min. Xylazine HCl (1 mg/kg) significantly reduced locomotor activity for 90 min. Amitraz produced a dose-dependent decrease in locomotor activity, lasting 75 min for the 0.05 mg/kg dose, 120 min for the 0.10 mg/kg dose, and 180 min for the 0.15 mg/kg dose. In a separate experiment, yohimbine administration immediately reversed the sedative effect of amitraz. This suggests there is a similarity in the mode of action of amitraz, xylazine and detomidine, as yohimbine acts primarily by blocking central alpha 2 -adrenoceptors that are stimulated by agents like xylazine. There was also a significant decrease in locomotor activity following injection of detomidine (0.02, 0.04 and 0.08 mg/kg) for 1.5, 3.5 and 5.0 h, respectively. The locomotor chamber is a useful, sensitive and highly reproducible tool for measuring spontaneous locomotor activity in the horse, which allows investigators to determine an agent's average time of onset, duration and intensity of effect on movement.

Animals↗
PubMed1997

Cost of care for cancer in a health maintenance organization.

The direct costs of medical care for cancer are examined at Kaiser Permanente (KP) in Northern California. Use data from July 1987 through June 1991 were obtained from KP automated files for all 21,977 KP patients in the Bay Area SEER registry with cancer at one of seven cancer sites. Medical charts were reviewed for a stratified sample of 886 patients. Costs were estimated for initial, continuing, and terminal care, and for all person time within 15 years of diagnosis, by stage at diagnosis. From diagnosis until death or 15 years, long-term costs attributable to cancer were as follows: breast, $35,000; colon, $42,000; rectum, $51,000; lung, $33,000; ovarian, $64,000; prostate, $29,000; and Non-Hodgkin's Lymphoma (NHL), $48,000. The utilization and cost results reported here may be useful in assessing the cost-effectiveness of cancer prevention and control programs, in adjusting capitation rates and budgets, and in estimating the aggregate medical care costs attributable to cancer.

Ambulatory Care↗
PubMed1996

Nasopharyngeal carcinoma: an EBV-associated tumour not significantly influenced by HIV-induced immunosuppression. The AIDS/Cancer Working Group.

We used a link between cancer (859,398 reports) and AIDS (50,050 reports) registries in the United States to study whether nasopharyngeal carcinoma (NPC) was increased in the population with AIDS. There was no indication of a significantly increased risk up to or after the AIDS diagnosis, which argues against progressively failing immunity being important in the development of this malignancy.

Adult↗