PubMed Health⌕ Search

Biomedical subjects

D Stevens

Publications and source records attributed to D Stevens.

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

Effects of high-dose inhaled fluticasone propionate via spacer on cell-mediated immunity in healthy volunteers.

BACKGROUND: Systemic corticosteroids are known to alter cell-mediated immunity (CMI). However, the effects of inhaled steroids on CMI are unclear. We therefore sought to assess CMI following high-dose inhaled steroids in healthy subjects. METHODS: Ten healthy nonasthmatic subjects self-administered fluticasone propionate (FP), 440 microg bid, with a spacer device. CMI was assessed by delayed hypersensitivity skin testing to multiple antigens and in vitro by phytohemagglutinin (PHA) stimulation of peripheral blood T lymphocytes. Percentages of CD3(+), CD4(+), and CD3(+)CD8(+) cells expressing CD69(+) were determined by three-color flow cytometry. Studies were conducted before and after 4 weeks of FP treatment. RESULTS: After 4 weeks of FP treatment, two of nine subjects became anergic, whereas six of nine subjects had reduced skin responses (one subject was excluded). Mean total skin test score fell from 18.4+/-10.9 to 9.1 +/-7.2 mm (p = 0.02). There was a decline in tuberculin responses in all four subjects who were positive prior to FP treatment. Following FP treatment, the percentage of unstimulated (from control subjects receiving saline solution) CD3(+)CD4(+)CD69(+) cells declined from 14.8+/-4.2% to 8. 5+/-4.6% (p = 0.02) and the CD3(+)CD8(+)CD69(+) cells decreased from 29.7+/-12.7% to 17.1 +/-5.0% (p = 0.007). PHA stimulation produced significant increases in the percentage of CD3(+)CD4(+)CD69(+) cells before and after FP treatment (67.0+/-9.1%, p<0.02 before FP; 55.4+/-17.0%, p<0.02 after FP), and in the percentage of CD3(+)CD8(+)CD69(+) cells before and after treatment (79.7+/-9.3%, p<0.03 before FP; 71.2+/-11.4%, p = 0. 008 after FP). CONCLUSIONS: High doses of FP suppress the proportion of activated circulating T cells but do not affect the ability of T cells to respond to direct stimulation with PHA. However, depression of skin test responses to antigens following treatment with FP suggests an impairment of in vivo clinical manifestations of T-cell activation by a mechanism that requires further investigation.

Administration, Inhalation↗
PubMed2000

[40 years of progress in breast imaging].

In the sixties, mammary diagnosis is just clinical, then the low contrast mammography, not very efficient, appears in the seventies. During the eighties, the ultrasound is set up while modern mammography with high contrast allows the non palpable breast lesions diagnosis. In the nineties years the mammography come before the clinical examination within the context of the breast cancer screening program. Some histological correlation are more specific about the ductal carcinoma in situ grading with microcalcifications, while new techniques (MRI, CT) are evaluated. At present the stereotactic large core breast biopsies benefit from the digital prone table, allow a histological diagnosis and avoid surgical excision of some indeterminate images. After the pernicious effects of imaging, we assess the progress according to the cancerous disease results. We also consider the problem of over-diagnosis and over-treatment of ductal carcinoma in situ.

Biopsy↗
PubMed2000

Severe pulmonary hypertension associated with COPD.

Pulmonary hypertension can be associated with chronic obstructive pulmonary disease (COPD). Mild to moderate elevations in pulmonary artery pressures are commonly reported. Previous studies included patients initially diagnosed with COPD and subsequently evaluated for pulmonary hypertension. The occurrence of COPD in patients being evaluated for pulmonary hypertension has not been reported. We performed a retrospective chart review of approximately 600 patients evaluated in a large tertiary care pulmonary hypertension clinic. Subjects were included if they were older than 40 years, had no other secondary causes of pulmonary hypertension and had evidence of COPD by pulmonary function studies or thoracic computed tomography. Criteria was met by five subjects (3 males and 2 females, mean age = 65 years) all of whom were past smokers. The average mean pulmonary artery pressure (MPAP) was 59 +/- 7 mm Hg. The mean pulmonary vascular resistance (PVR) was 15.2 +/- 5 mmHg/liter/min. Only one patient had a fall in MPAP of more than 10% and a greater than 30% decline in PVR following infusion of adenosine to test vasodilator responsiveness. COPD is rare in a population referred primarily for evaluation of pulmonary hypertension. Although infrequent, severe pulmonary hypertension may be associated with COPD.

Adenosine↗
PubMed1999

Molecular basis and enzymatic properties of glucose 6-phosphate dehydrogenase volendam, leading to chronic nonspherocytic anemia, granulocyte dysfunction, and increased susceptibility to infections.

We have investigated the blood cells from a woman with a low degree of chronic nonspherocytic hemolytic anemia and frequent bacterial infections accompanied by icterus and anemia. The activity of glucose 6-phosphate dehydrogenase (G6PD) in her red blood cells (RBCs) was below detection level, and in her leukocytes less than 3% of normal. In cultured skin fibroblasts, G6PD activity was approximately 15% of normal, with 4- to 5-fold increased Michaelis constant (Km) for NADP and for glucose 6-phosphate. Activated neutrophils showed a decreased respiratory burst. Family studies showed normal G6PD activity in the RBCs from all family members, including both parents and the 2 daughters of the patient. Sequencing of polymerase chain reaction (PCR)-amplified genomic DNA showed a novel, heterozygous 514C-->T mutation, predicting a Pro172-->Ser replacement. Analysis of G6PD RNA from the patient's leukocytes and fibroblasts showed only transcripts with the 514C-->T mutation. This was explained by the pattern of X-chromosome inactivation, studied by means of the human androgen receptor (HUMARA) assay, which proved to be skewed in the patient, her mother, and one of the patient's daughters. Thus, the patient has inherited a de novo mutation in G6PD from her father and an X-chromosome inactivation determinant from her mother, causing exclusive expression of the mutated G6PD allele. Purified mutant protein from an Escherichia coli expression system showed strongly decreased specific activity, increased Km for NADP and for glucose 6-phosphate, and increased heat lability, which indicates that the defective phenotype is due to 2 synergistic molecular dysfunctions: decreased catalytic efficiency and protein instability.

Adult↗
PubMed1999

Human hexose-6-phosphate dehydrogenase (glucose 1-dehydrogenase) encoded at 1p36: coding sequence and expression.

Using the published protein sequence from a rabbit microsomal glucose-6-phosphate dehydrogenase G6PD we have isolated and sequenced a cDNA clone coding for its human equivalent, which is also known as hexose-6-phosphate dehydrogenase (H6PD) and glucose dehydrogenase. The corresponding genomic sequence is in the databases enabling its localization to chromosome 1p36. The gene spans 37 kb and consists of 5 exons, the fifth of which codes for more than half of the 89 kDa protein. The first intron is a 10 kb insertion in the 5' untranslated sequence. The predicted mRNA has an exceptionally long (6.5 kb) 3' untranslated sequence. The predicted protein shows extensive homology with X-linked G6PD, suggesting the two genes share a common ancestor but no intron positions are conserved between the two genes suggesting the gene duplication was an ancient event. The C-terminal portion of the protein is not homologous with G6PD but shows limited homology with proteins of unknown function found throughout evolution and encoded next to G6PD in various micro-organisms. Intriguingly this C-terminal portion has some homology with the N-terminal sequence of Plasmodium falciparum G6PD.

Amino Acid Sequence↗
PubMed1999

Treatment with tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor increases epidermal Langerhans' cell numbers in cancer patients.

Dendritic cells (DCs) initiate primary and stimulate secondary T-cell responses. We conducted a phase I trial of tumor necrosis factor (TNF-alpha) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with cancer to increase DCs in peripheral blood or skin based on in vitro data that showed that CD34(+) hematopoietic precursors require these cytokines to mature into functional antigen-presenting DCs. Eleven patients were treated for 7 days with GM-CSF, 125 microg/m(2) twice daily as subcutaneous injections, and TNF-alpha as a continuous infusion at dose levels of 25, 50, or 100 microg/m(2)/day. The maximum tolerated dose of TNF-alpha was 50 microg/m(2)/day with this dose of GM-CSF; dose-limiting toxicities occurred in both patients treated with 100 microg/m(2)/day. One became thrombocytopenic and the other had transient confusion. Epidermal Langerhans' cells were quantitated by S100 staining of skin biopsies and DC precursors in peripheral blood by colony-forming unit dendritic (CFU-dendritic) assays. S100-positive cells in the epidermis doubled after treatment (2.55 S100(+) cells/high-power field before treatment to 6.05 after treatment, p = 0.029). CFU-dendritic in peripheral blood increased after treatment in 3 colorectal cancer patients but not in 3 patients with melanoma. CD11c(+) or CD123(+), HLA-DR(bright), lineage-negative dendritic cell precursors were not increased in peripheral blood mononuclear cells. This trial demonstrates that treatment with TNF-alpha and GM-CSF can increase the number of DCs in the skin and the number of dendritic cell precursors in the blood of some patients with cancer. This approach may increase the efficacy of vaccination to tumor antigens in cancer patients.

Adult↗
PubMed1999

Applying HEDIS clinical measures to community health centers: a feasibility study.

Since participation in managed care is critical for community health centers' (CHCs) survival, centers must demonstrate their good performance to purchasers (e.g., state Medicaid agencies) and health plans. Such measures also can contribute to quality improvement. Ideally, the effort would use measures and methods widely recognized in the managed care industry, logically the Health Plan Employer Data and Information Set (HEDIS). This article summarizes a feasibility study of applying HEDIS clinical measures to CHCs as providers. It finds that, with concerted, well-directed efforts, it will be possible to use clinical HEDIS measures in health centers.

Community Health Centers↗
PubMed1999

Complications of airway management in very-low-birth-weight infants.

OBJECTIVE: To define the incidence of complications of endotracheal intubation and the factors associated with these complications. STUDY DESIGN: During a 22-month period, 227 intubated infants weighing <1,501 g were followed prospectively in a neonatal intensive care unit. Detailed records of events associated with airway management were kept after every intubation, in addition to clinical data. RESULTS: Eleven infants (4.8%) developed respiratory stridor after extubation which was treated with either systemic corticosteroids, racemic epinephrine and/or reintubation for respiratory failure. Four infants were submitted for bronchoscopy, mild subglottic stenosis with tracheal edema was found in 1 patient, granulation tissue and airway edema were noted in 3 infants. Traumatic intubation, prolonged ventilation, multiple intubations and bacterial colonization of the endotracheal tube were the factors associated with postextubation stridor. CONCLUSIONS: Subglottic stenosis is an infrequent complication of endotracheal intubation with current airway management of very-low-birth-weight infants. Less severe complications are still common, but they are usually amenable to clinical treatment. Bronchoscopy should be performed selectively only in infants with clinical evidence of airway obstruction after extubation.

Adrenal Cortex Hormones↗
PubMed1999

Comparison of hallway and treadmill six-minute walk tests.

The 6-min walk test (SMWT) performed in the hallway (HW) is used as a clinical indicator of functional capacity in patients with lung disease. A 6-min walk test utilizing a treadmill (TM) is easier to perform and allows easier patient monitoring. Therefore, we formulated a standardized TM SMWT protocol and compared the results with those of a HW SMWT. All patients were enrolled in a pulmonary rehabilitation program. Patients with current infection, recent change in inhaled medications or oral steroid use, and significant cardiovascular disease were excluded. Each subject performed three HW SMWTs and three TM SMWTs assigned randomly on subsequent days. There was a 30-min rest between each walk and at least a 48-h rest between each test day. All patients completed both HW and TM SMWT within 7 d. Supplemental oxygen was utilized or increased if the saturation fell below 88%. The best of the three tests was used for data analysis. Twenty-one subjects completed the protocol. The mean age was 65 +/- 10.9 yr (range, 35 to 79 yr). Ten subjects were receiving supplemental oxygen. The mean FEV(1) was 1.07 +/- 0.53 L. The mean HW SMWT distance was 1,228 +/- 255 ft (range, 612 to 1,679 ft) and the mean TM SMWT distance was 1,060 +/- 389 ft (range, 475 to 1,819 ft), which were statistically different (p = 0.01). The mean difference was 168 +/- 280 ft (range, -326 to 743 ft). Oxygen saturation and supplemental oxygen requirements did not differ significantly. The intra-test variability of the three HW SMWTs was similar to the three TM SMWTs and no significant difference in the coefficient of variation was found. A standardized TM SMWT is feasible and allows easier patient monitoring, but there is a statistically significant difference between the HW and TM SMWT distance and therefore they are not interchangeable. However, the intratest reproducibility of the TM and HW SMWTs are similar when three walks are performed in a single test session. The role of the TM SMWT in pulmonary rehabilitation requires further exploration.

Adult↗
PubMed1998

[Treatment of breast cancer after 70 years of age. Report of 1143 cases].

STUDY AIM: Breast cancer is the most frequent type of cancer in women, increasing in frequency with the elderly. In Europe, a third of new breast cancers occur in women over 70 years of age. The aim of this retrospective study was to analyse the tumoural lesions and therapeutic results in a female population over 70, treated in the same medical centre over a 15-year period. PATIENTS AND METHODS: From 1978 to 1992, 1,143 female patients aged 70 or over were treated for a unilateral breast cancer without metastases and followed-up during a mean 6-year period. The initial treatment was surgical in 1,012 patients: radical mastectomy in 95% of the cases with axillary node dissection in 97.6%. Adjuvant radiotherapy was performed in 289 patients and adjuvant treatment with Tamoxifen in 411 patients. The results were compared with those obtained in 2,947 patients aged 50 to 69, treated during the same period in the same medical centre. RESULTS: The 5-year survival rate in women 70 and over was 80% vs 85.5% in women aged 50 to 69 (P < 0.000001). The same rate of loco-regional recurrences and metastases occurred in both populations. In the patients who initially underwent surgery, after multivariate analysis according to the Cox model, the prognosis factors (similar to those observed in the group of younger women) were: the number of involved nodes (P = 0.000001), the clinical size of the tumour (P = 0.00001), the histological grade (P = 0.01), and the estrogen receptors (P = 0.02). CONCLUSIONS: In this series, the treatment was focused on surgery complemented with adjuvant radiotherapy according to node invasion and adjuvant hormonotherapy according mostly to hormonal receptors. However, the complete treatment could not be applied to all cases: only 50% of patients with node involvement were irradiated. The 5-year survival rate lower than that of younger patients may be attributed to incomplete adjuvant treatment. Specific controlled trials taking into account quality of life had to be undertaken in elderly patients in order to adjust the treatment in relation with the patients' age and physiological condition.

Age Factors↗
PubMed1998

Neonatal infections with Pseudomonas aeruginosa associated with a water-bath used to thaw fresh frozen plasma.

In our 15-bed neonatal intensive care unit (NICU), four new-borns were found to be colonized or infected with Pseudomonas aeruginosa within a period of one week. To identify the outbreak source, three independent studies were performed: epidemiological investigation, environmental surveillance and genotypic typing of isolates. Although epidemiological investigation by a case-control study revealed no conclusive results, the transfusion of fresh frozen plasma (FFP) and human albumin (HA) appeared to be the factor with highest risk. Environmental surveillance and random amplification of polymorphic DNA (RAPD) of isolates identified a water-bath used to warm FFP and HA as the likely reservoir for the outbreak. Further spread of the organism did not occur after elimination of this water-bath from the NICU. RAPD identified in addition an isolate from an infant hospitalized in the NICU five months before the outbreak with a pattern matching the one of the outbreak cluster.

Belgium↗
PubMed1998

PROMM: the expanding phenotype. A family with proximal myopathy, myotonia and deafness.

We describe a family with a proximal myopathy, subclinical EMG myotonia, cataracts and deafness. Transmission through two generations and down the male line confirms autosomal dominant inheritance. There was no abnormal expansion of the CTG triplet repeat in the last exon of the dystrophia myotonica protein kinase (DMPK) gene associated with myotonic dystrophy. Heteroduplex analysis of all but the promoter region of the DMPK gene has excluded point mutations in this gene as an underlying cause for this myotonic disorder. The family was not sufficiently informative to exclude linkage to the sodium channel gene SCN4A or the chloride channel gene CLC1. This family clearly fulfils the recently established diagnostic criteria for PROMM (proximal myotonic myopathy) and in addition shows consistent severe deafness as a hitherto undescribed feature of PROMM. We discuss the diagnostic criteria of PROMM in relation to this family and other recent papers, all of which would now fulfil the aforementioned diagnostic criteria for PROMM.

Adult↗
PubMed1998

Identification of new verocytotoxin type 2 variant B-subunit genes in human and animal Escherichia coli isolates.

The sequence of a verocytotoxin 2 (VT2) variant gene that was untypeable by the B subunit PCR and restriction fragment length polymorphism analysis (PCR-RFLP) method described by Tyler et al. (S. D. Tyler, W. M. Johnson, H. Lior, G. Wang, and K. R. Rozee, J. Clin. Microbiol. 29:1339-1343, 1991) was determined and compared with published sequences. It was highly homologous to two recently reported VT2 variant sequences. The PCR-RFLP method described by Tyler et al. was extended to include these new sequences. New VT2 variants were identified in 65 of 359 VT-producing Escherichia coli (VTEC) with newly designed primers (VT2-cm and VT2-f) and were characterized as well by restriction analysis of the amplification products obtained with another VT2-specific primer pair (VT2-e and VT2-f). The VT genes harbored by 64 of these isolates proved to be untypeable by Tyler's PCR-RFLP method because no amplification was obtained with the primers used with this method (VT2-c and VT2-d). The last isolate harbored the new variant gene in addition to VT2vh-a. None of the isolates harboring these new toxin genes belonged to serogroups O157, O26, O103, O111, and O145. All 65 isolates were negative for the eaeA gene and were significantly less frequently enterohemolytic or positive for the enterohemorrhagic E. coli (EHEC) virulence plasmid than non-O157 VTEC isolates harboring other VT2 genes. They were also less frequently isolated from patients with EHEC-associated symptoms. The extended PCR-RFLP typing method is a useful tool to identify less-virulent VTEC isolates and for VT genotyping in epidemiological studies with non-O157 strains.

Animals↗
PubMed1997

Epidemiology and clinical management of meningococcal disease in west Gloucestershire: retrospective, population based study.

OBJECTIVE: To study changes in the epidemiology and management of meningococcal disease in one health district during a period of high local incidence of disease. DESIGN: Prospective case ascertainment and data collection over 14 years, with retrospective analysis of cases. SETTING: West Gloucestershire (population 320,000). SUBJECTS: Residents developing meningococcal disease between 1 January 1982 and 31 December 1995. RESULTS: 252 cases of invasive meningococcal disease were identified, of which 102 (40%) were officially notified and 191 (76%) were confirmed by culture from a deep site. The observed disease incidence of 5.6/100,000/year was about 2.7 times the national incidence (as measured by either statutory notifications or reference laboratory reports). The period 1983-90 was characterised by a prolonged localised outbreak due to serogroup B serotype 15 sulphonamide resistant (B15R) strains. General practitioners gave benzylpenicillin before hospital admission to 18% of patients who presented with meningococcal disease in the first half of the study period and to 40% who presented in the second half. The overall case fatality rate was 6.7% (17/252). Four deaths were directly or indirectly related to lumbar puncture. Of 120 patients whose lumbar puncture yielded meningococci, nine (8%) showed no abnormality on initial examination. CONCLUSIONS: Neither laboratory records nor formal notifications alone can give an accurate estimate of the incidence of meningococcal disease. Because of the dangers of lumbar puncture, the frequency of misleading negative initial findings, and the advent of new diagnostic techniques, the need for samples of cerebrospinal fluid should be critically questioned in each case of suspected meningococcal disease.

Adolescent↗
PubMed1997

Virulence factors of verocytotoxin-producing Escherichia coli isolated from raw meats.

PCR for verocytotoxin-producing Escherichia coli (VTEC) was positive in 4.6% of 2,440 raw meat samples; only beef, sheep, and venison samples were positive. None of the isolated VTEC strains belonged to serogroup O157. Additional virulence factors were detected in only a minority of strains, suggesting that most of these meat VTEC isolates are not pathogenic.

Animals↗