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Biomedical subjects

A Becker

Publications and source records attributed to A Becker.

At least 109 records · Page 6Linked to original sources
PubMed2001

[Bone density and 25-OH vitamin D serum level in patients with systemic lupus erythematosus].

OBJECTIVE: To clarify the influence of vitamin D metabolism on bone mineral density (BMD) or bone metabolism in patients with systemic lupus erythematosus (SLE). METHODS: 57 consecutive patients in our department (mean age 33.9 years, 44 female, 13 male) were studied. BMD was measured with dual-X-ray absorptiometry at the lumbar spine and femoral neck. Biochemical investigation of bone metabolism included measurement of vitamin D metabolites, intact parathyroid hormone (PTH), serum osteocalcin und urinary pyridinoline-crosslink excretion. RESULTS: 25 patients had 25-OH cholecalciferol serum values below the normal range after adjustment for seasonal changes; 9 patients were severely vitamin D depleted with 25-OH vitamin D serum values below 5 ng/ml. Low 25-OH-vitamin D was significantly associated with high disease activity. Mean 1.25 (OH)2-vitamin D, PTH, osteocalcin and crosslink excretion were in the normal range. Thirty-six patients had normal BMD; 5 patients had osteoporosis according to WHO diagnosis criteria. No correlation of biochemical parameters of bone metabolism with BMD was found. CONCLUSION: Severe vitamin D depletion was common in this group of patients with SLE even after adjustment for seasonal variations, especially in patients with high disease activity. Therefore, D-hypovitaminosis should be included in the differential diagnosis in patients with SLE presenting with low bone mass.

Adult↗
PubMed2001

Immunohistochemical localization of zona pellucida proteins ZPA, ZPB and ZPC in human, cynomolgus monkey and mouse ovaries.

The zona pellucida of mammalian oocytes plays an important role in binding and activation of sperm cells during the molecular events leading to fertilization. The genes coding for the three zona pellucida glycoproteins ZPA, ZPB, and ZPC of various species including mouse, dog, and human have been cloned and sequenced by several groups. However, it has remained a matter of debate as to whether the oocytes alone or in conjunction with the surrounding granulosa cells express and deposit these proteins to form the zona pellucida matrix. Addressing this unresolved issue, we assessed the expression and localization of all three zona pellucida proteins in ovaries of human, cynomolgus monkey and mice using immunohistochemical methods. In addition, oocyte-specific expression of ZPC from the primordial stage onward was confirmed by in situ hybridization. In sections of human ovaries, ZPA, ZPB, and ZPC proteins were immunohistochemically detected in the cytoplasms of primordial oocytes and during later stages of folliculogenesis in the zona pellucida matrices of oocytes. In sections fixed with formalin, a clear homogeneous ring was visible around the oocyte and no staining of granulosa cells was observed. In contrast, staining of ZP proteins was also observed between granulosa cells when Bouin's reagent had been used for tissue fixation. Thus, the original zona pellucida architecture was better preserved by formalin fixation. We further demonstrated that dissolution of the zona pellucida of isolated bovine oocytes occurred after they were exposed to Bouin's reagent. In summary, these results demonstrate that in mice, monkeys and humans, zona proteins are expressed and assembled exclusively by the oocyte and not by the granulosa cells. Previously observed results of ZP expression by an involvement of granulosa cells might therefore be the result of an improper fixation of the tissues leading to the disruption of the zona pellucida. Additionally this study highlights the importance of choosing the correct fixative for immunohistochemistry, not only for the usual reason of retaining antigenicity, but rather to retain the entire architectural structure.

Acetic Acid↗
PubMed2001

The relationship between introduction of American society of clinical oncology guidelines and the use of colony-stimulating factors in clinical practice in a Paris university hospital.

BACKGROUND: Clinical practice guidelines are issued periodically by professional medical societies or committees to assist practitioners in clinical decision making. However, it is unclear whether such guidelines have any lasting impact on clinical practice. OBJECTIVE: The purpose of this study was to assess the impact of the American Society of Clinical Oncology (ASCO) guidelines regarding use of hematopoietic colony-stimulating factors (CSF) on cancer care in a university hospital in Paris. METHODS: The study was performed at Hĵpital Tenon, an 830-bed university hospital in Paris, in 1996 and 1997, both before and after the ASCO guidelines were implemented. The guidelines were first disseminated as a continuing medical education program and then actively implemented using a CSF prescription order form summarizing the guidelines. This form had to be used during the patient consultation and was sent to the Hĵpital Tenon pharmacy for CSF dispensation. Even if CSF use did not comply with the ASCO guidelines, the pharmacy filled the prescription. Seven other university hospitals in Paris, where the ASCO guidelines were not actively implemented, comprised the control group. The main outcome measure was the proportion of prescriptions in compliance with the 1996 update of the ASCO guidelines. Secondary outcome measures were the proportions of prescriptions in compliance with ASCO guidelines regarding primary prophylactic, secondary prophylactic, and therapeutic CSF administration. RESULTS: Before implementation of the ASCO guidelines, CSF use in compliance with the guidelines was 39% (41/105) at the study site and 31% (16/51) at the control sites (P > 0.05). Six months after dissemination and implementation of the guidelines, the proportion of CSF prescriptions complying with ASCO guidelines increased significantly versus baseline (P = 0.003) in the study group, to 61% (50/82). However, even after the guidelines were implemented, compliance with guidelines on primary prophylactic CSF administration did not change significantly versus before implementation in the study group (12% [5/41] before implementation vs 6% [2/33] after implementation; P > 0.05). CONCLUSIONS: The results suggest an association between the active implementation strategy (continuing medical education and CSF prescription reminder form) and physician compliance with the ASCO guidelines. Implementation of the ASCO guidelines appears to have had some impact on medical practice.

Colony-Stimulating Factors↗
PubMed2001

Effect of 5-hydroxytryptamine 1A receptor agonist BAY X 3702 on BCL-2 and BAX proteins level in the ipsilateral cerebral cortex of rats after transient focal ischaemia.

The proto-oncogene B-cell lymphoma protein 2 (BCL-2) and its homologues are important modulators of cellular survival after transient brain ischaemia. In the present study we used western blotting to elucidate if the stimulation of 5-hydroxytryptamine 1A type receptors with their agonist BAY X 3702 results in regulation of BCL-2 family proteins. Treatment with BAY X 3702 resulted in elevated BCL-2 protein level in the ipsilateral cerebral cortex of animals as early as at 6 and 12 h of reperfusion, this effect becoming more pronounced at 24 h. BAY X 3702 administration caused no change in BCL-2-associated protein X content during reperfusion. The effect of BAY X 3702 on the level of death-inhibiting protein BCL-2 in the brain during ischaemia/reperfusion could contribute to the neuroprotective potency of the drug.

Animals↗
PubMed2001

Correlation of coronary calcification and angiographically documented stenoses in patients with suspected coronary artery disease: results of 1,764 patients.

OBJECTIVES: This study correlated the electron beam computed tomographic (EBCT) calcium scores with the results of coronary angiography in symptomatic patients in order to assess its value to predict or exclude significant coronary artery disease (CAD). BACKGROUND: Electron beam computed tomography is a sensitive method to detect coronary calcium. However, it is unclear whether it may play a role as a filter before invasive procedures in symptomatic patients. METHODS: A total of 1,764 patients (1,225 men and 539 women) with suspected CAD from a single center were included in our study. All patients underwent calcium screening with EBCT (C150XP Imatron) and conventional coronary angiography. RESULTS: Fifty-six percent of men and 47% of women revealed significant coronary stenoses (> or =50%). Total exclusion of coronary calcium (14% of the study group) was associated with an extremely low probability of stenosis (<1%). With calcium scores > or =20th, > or =100th or > or =75th percentile of age groups, the sensitivity to detect stenoses decreased to 97%, 93% and 81%, respectively, in men and to 98%, 82% and 76%, respectively, in women. At the same time, the specificity increased up to 77% in men and women. There was a significant difference in coronary calcium between men and women in all age groups; however, receiver-operating characteristic curves indicated that the test can be performed with equal accuracy in all of these subgroups. CONCLUSIONS: Calcium screening with EBCT is a highly sensitive and moderately specific test to predict stenotic disease. Exclusion of coronary calcium defines a substantial subgroup of patients, albeit symptomatic, with a very low probability of significant stenoses.

Adult↗
PubMed2001

Pressure-guided nonsurgical myocardial reduction induced by small septal infarctions in hypertrophic obstructive cardiomyopathy.

OBJECTIVES: We sought to assess the safety and efficacy of pressure-guided nonsurgical myocardial reduction (NSMR) with the induction of small septal infarctions in patients with hypertrophic obstructive cardiomyopathy (HOCM). BACKGROUND: Nonsurgical myocardial reduction has been shown to decrease left ventricular outflow tract (LVOT) obstruction and to improve symptoms in patients with HOCM. Infarct sizes differ considerably among studies published so far. METHODS: In 50 patients, the LVOT gradient was invasively determined at the time of the intervention, four to six months (n = 49) and 12 to 18 months (n = 25) after NSMR. New York Heart Association functional class and quality of life were assessed by using a standard questionnaire. Exercise capacity was tested by spiro-ergometry. Left ventricular (LV) mass was determined by electron beam computed tomography. RESULTS: Small septal infarctions (mean creatine kinase value 413 +/- 193 U/l) resulted in a sustained decrease in LVOT gradients, from 80 +/- 33 to 18 +/- 17 mm Hg after four to six months (p < 0.001, n = 49) and to 17 +/- 15 mm Hg (p < 0.001, n = 25) after 12 to 18 months. Nonsurgical myocardial reduction was followed by a decrease in LV hypertrophy, which was associated with a sustained increase in exercise capacity, as well as improvement in quality of life. CONCLUSIONS: Pressure-guided NSMR inducing small septal infarctions was sufficient to result in a sustained decrease in LVOT obstruction and to improve symptoms. The incidence of complications, such as complete heart block with necessary permanent pacemaker implantation (<10%), seems to be diminished by minimizing the infarct size.

Aged↗
PubMed2001

Long-term administration of high-dose deferoxamine 2 days per week in thalassemic patients.

OBJECTIVE: Compliance with parenteral administration of deferoxamine is often poor in thalassemic patients with iron overload. We tested the efficacy and tolerance of the drug at high dosage 2 d per week for 24 months in two adult thalassemic patients with permanently high serum ferritin using a portable pump and an implanted chamber. METHODS: Deferoxamine was administered using a pressure-operated portable pump through an implanted chamber. The patients were infused over 48 h every week with 198 mg/kg/d (patient 1) and 170 mg/kg/d (patient 2). Serum ferritin levels were measured at regular intervals. RESULTS: Serum ferritin decreased progressively from 2967 to 457 microg/L in patient 1 and from 6476 to 1951 microg/L in patient 2. Compliance and tolerance to treatment were excellent in the two patients. CONCLUSION: Intravenous administration of high-dose deferoxamine over 48 h per week using a portable pump and implanted chamber improved compliance in two thalassemic adult patients, resulting in a significant decrease in iron overload. We suggest that high-dose chelation therapy should be assessed in selected groups of iron-overload thalassemic patients receiving regular blood transfusions.

Adult↗
PubMed2001

Receptor-targeted optical imaging of tumors with near-infrared fluorescent ligands.

We report here the in vivo diagnostic use of a peptide-dye conjugate consisting of a cyanine dye and the somatostatin analog octreotate as a contrast agent for optical tumor imaging. When used in whole-body in vivo imaging of mouse xenografts, indotricarbocyanine-octreotate accumulated in tumor tissue. Tumor fluorescence rapidly increased and was more than threefold higher than that of normal tissue from 3 to 24 h after application. The targeting conjugate was also specifically internalized by primary human neuroendocrine tumor cells. This imaging approach, combining the specificity of ligand/receptor interaction with near-infrared fluorescence detection, may be applied in various other fields of cancer diagnosis.

Animals↗
PubMed2001

Preconditioning-induced neuroprotection is mediated by reactive oxygen species and activation of the transcription factor nuclear factor-kappaB.

Preconditioning by a sublethal stimulus induces tolerance to a subsequent, otherwise lethal insult and it has been suggested that reactive oxygen species (ROS) are involved in this phenomenon. In the present study, we determined whether preconditioning activates the transcription factor nuclear factor-kappaB (NF-kappaB) and how this activation contributes to preconditioning-induced inhibition of neuronal apoptosis. Preconditioning was performed by incubating mixed cultures of neurons and astrocytes from neonatal rat hippocampus with xanthine/xanthine oxidase or FeSO4 for 15 min followed by 24 h of recovery which protected the neurons against subsequent staurosporine-induced (200 nM, 24 h) apoptosis. The cellular ROS content increased during preconditioning, but returned to basal levels after removal of xanthine/xanthine oxidase or FeSO4. We detected a transient activation of NF-kappaB 4 h after preconditioning as shown by immunocytochemistry, by a decrease in the protein level of IkappaBalpha as well as by electrophoretic mobility shift assay. Preconditioning-mediated neuroprotection was abolished by antioxidants, inhibitors of NF-kappaB activation and cycloheximide suggesting the involvement of ROS, an activation of NF-kappaB and de novo protein synthesis in preconditioning-mediated rescue pathways. Furthermore, preconditioning increased the protein level of Mn-superoxide dismutase which could be blocked by antioxidants, cycloheximide and kappaB decoy DNA. Our data suggest that inhibition of staurosporine-induced neuronal apoptosis by preconditioning with xanthine/xanthine oxidase or FeSO4 involves an activation of NF-kappaB and an increase in the protein level of Mn-superoxide dismutase.

Acetylcysteine↗
PubMed2001

[Cost evaluation by a patient questionnaire: pilot study of a weekly cost diary].

Weekly cost diaries are instruments to measure direct and indirect costs prospectively by using patient data. First we searched MEDLINE for information concerning the use of diaries in health care and their methodological evaluation. Based on a Dutch weekly cost diary we developed an instrument for patients with acute or chronic back pain to be completed following participation in an inpatient rehabilitation measure. Its use was tested in an explorative pilot study. We asked for all costs and resource use due to back pain (all direct medical and non medical costs as well as indirect costs) occurring in a 4-week follow-up period, irrespective of the cost carrier. The total response rate was 58%. Patients spent an average 13 minutes a week for completing the questionnaire, without reporting any major methodological difficulties. Some 30% percent of overall costs were direct costs, the majority being non-recurring costs for assistive devices such as mattresses and mattress frames. Excluding these, monthly direct costs per patient were 270 DM on average. Indirect costs, mainly due to absence from salaried work, amounted to an average 1634 DM per patient, with marked variation. Our study results show that this instrument is basically useful and feasible in this indication. Further studies with larger and representative samples are needed to evaluate data quality. It is suggested that weekly cost diaries can be useful tools in particular in decentralized health care systems to measure costs from the societal perspective.

Adult↗
PubMed2001

[Experimental validation of DXA and MRI-based bone density measurement by ash-method].

Different methods have been established for bone density measurements such as dual energy X-ray absorptiometry (DXA), quantitative computertomography (QCT), and scintigraphy (VQ-Scan). There are hints that magnetic resonance imaging (MRI) might become a new option for the evaluation of bone density. The aim of this study was to investigate correlations between MRI vs. DXA and MRI vs. mineral content of lumbar vertebrae. Data were obtained from ten lumbar vertebral bodies of cattles. The T-1 MRI-sequences SE, PS, and the T-2 Sequence STIR were used for analysis. Total pixel numbers and a pixel per area ratio were determined. Values were compared to DXA-measurements, to the wet weight, and to separated measurements of the spongious, trabecular, and total mineral content of the vertebral body after ashing. We found correlations between DXA (g/vertebral body) vs. mineral content by ash-method (0.918; p < 0.01), DXA vs. MRI (SE-sequence) (-0.872; p < 0.01), and MRI (SE-sequence) vs. mineral content (0.775; p < 0.01). No correlations were found between PS- or STIR-sequences and the ash-method. This study shows that the determination of the bone mineral content of vertebrae is possible applying MRI in the T1-weighted SE-sequence. Without radiation, the MRI provides additionally early detection of trabecular lesions, fractures, and deformities at the spine, without other diagnostic procedures becoming necessary.

Absorptiometry, Photon↗
PubMed2001

[MR-morphological changes of the metacarpophalangeal joints in patients with rheumatoid arthritis: Comparison of early and chronical stages].

UNLABELLED: MR-morphological changes of the metacarpophalangeal joints in patients with rheumatoid arthritis: Comparison of early and chronical stages. PURPOSE: Evaluation of MRI findings in the metacarpophalangeal (MCP) joints in patients with early (eRA) and chronical rheumatoid arthritis (cRA). MATERIAL AND METHODS: In 22 RA patients (9 with disease duration </= 1.5 years = eRA) the dominant hands were examined by MRI in coronal T(2) weighted turbo-spin-echo (TSE). T(1) weighted spin-echo (SE) sequences before and after injection of Gd-DTPA and fat-suppressed short tau inversion recovery (STIR) sequences, followed by miniarthroscopy (MA) of the MCP II joint after an interval of 24 hours. MRI and MA findings were assessed using standardised semiquantitative items of synovial and bony pathologies and a statistical comparison between eRA and cRA patients was performed. RESULTS: In MRI synovial proliferation was detected in 13/13 cRA and 8/9 eRA patients. It was statistically not significant; the degree of synovial proliferation was however lower in the eRA group. All eRA patients with synovial changes showed enhancement after administration of contrast medium, a marker which correlated with the clinical activity. In 2/13 cRA patients no uptake of contrast medium was evident. Bony erosions and strongly narrowing joint space correlated with disease duration and were documented significantly rarer in the eRA patients (1/9, 2/9) than in the cRA patients (9/13, 10/13). CONCLUSION: In RA patients, MRI of the metacarpophalangeal joints can detect specific pathological changes which are observed significantly more often in either early or chronic stages and which are associated with disease activity and duration.

Adult↗
PubMed2001

The role of symptomatic colds in asthma exacerbations: Influence of outdoor allergens and air pollutants.

BACKGROUND: Both air pollutants and respiratory viral infections have been recognized to be important triggers of asthma exacerbations, but the possible interaction of these has not been assessed in an epidemiologic study. OBJECTIVE: In this study, we aimed to assess the possible associations of symptomatic colds with outdoor allergens and air pollutants in exacerbating asthma. METHODS: A total of 57 adults and children with asthma participated in a 1-year study in Vancouver, British Columbia. Diary cards recording symptoms of asthma and colds, medication usage, and peak expiratory flow rates were completed twice daily. Outdoor air pollutant levels and levels of pollen and fungal spores were measured. Levels were examined for associations with exacerbations of asthma with symptoms of a cold, as compared with asthma exacerbations with no cold symptoms and colds in the absence of asthma exacerbations. RESULTS: Of 130 asthma exacerbations, 47% were associated with cold symptoms (accounting for 44% of episodes of colds). Asthma exacerbations with colds were associated with higher levels of sulfur dioxide, and nitric oxide during March to November in comparison with asthma exacerbations without cold symptoms (P <.018). Cold-symptom days overall were more common in winter and were significantly associated with lower temperatures, lower ozone levels, and higher sulfur dioxide, nitrogen dioxide, nitrogen oxide (NO and NO(x)), and carbon monoxide levels. CONCLUSIONS: Asthma exacerbations are commonly associated with cold symptoms. These episodes are associated with higher levels of sulfur dioxide and nitrogen oxides from March to November in comparison with asthma exacerbations without cold symptoms.

Adolescent↗
PubMed2001

Image accuracy of plain film radiography and computerized tomography in assessing morphological abnormality of impacted teeth.

This study compares the image accuracy of computerized tomography (CT) with that of plain film radiography (PFR) in analyzing the 3-dimensional shape of impacted teeth suspected of being malformed. Eighteen patients with 22 malformed teeth were studied by PFR and CT. Crown shape, root shape, crown/root relationship, and tooth inclination and structure were assessed by PFR and CT. CT was found to be superior to PFR in showing the multiplanar shape of tooth crown and root, crown/root relationship, and tooth inclination (P <.001). No difference was found in the representation of tooth structures. The findings demonstrate that CT imaging is useful to diagnose and plan treatment for patients with unerupted and malformed teeth.

Adolescent↗
PubMed2001

Prosthetic considerations in the restoration of orthodontically treated maxillary lateral incisors to replace missing central incisors: a clinical report.

The treatment of young patients with missing maxillary incisors poses a challenge to prosthodontists and orthodontists. The 2 principal treatment options are (1) the reopening or maintenance of space for future autotransplantation and/or prosthodontic restoration of the missing teeth, or (2) total orthodontic space closure, followed by prosthodontic modification of the lateral incisors to simulate the central incisors. This article discusses only the second option and describes 2 alternative methods for the modification of crown anatomy. These procedures facilitate the orthodontic closure of missing central incisor spaces to ensure satisfactory, esthetic results.

Adolescent↗
PubMed2001

Orthodontic treatment for disabled children--a survey of patient and appliance management.

The objective of this article was to investigate the management problems encountered during the orthodontic treatment of children with disability, and took the form of a retrospective analysis. The investigation took place at the Center for the Treatment of Cranio-facial Disorders, Department of Orthodontics, Hebrew University Hadassah School of Dental Medicine, Jerusalem, Israel, between years 1989 and 1997. The subjects were the 37 children with mental and/or physical disability whose orthodontic treatment was either completed or nearly completed, whose parents were given a questionnaire. Thirty-five patients responded with a mean age of 13 years (range 7-21 years), representing 94.6 per cent of the sample. Most of the patients (94.3 per cent) were able to conclude the orthodontic treatment and 91.4 per cent of the parents reported that the added responsibilities were either negligible or bearable. In 63 per cent of the children, compliance increased during the treatment as anxiety decreased. The problems encountered with fixed appliances were generally more severe than with removable appliances. The two major obstacles were attendance at frequent and regular intervals (37.1 per cent) and maintaining an appropriate level of oral hygiene (37.1 per cent). Children with a disability are able and willing to undergo orthodontic treatment. Recommendations intended to facilitate management are presented.

Adolescent↗
PubMed2001

Sutureless closed hemorrhoidectomy: a new technique.

OBJECTIVE: To compare a new technique of radical hemorrhoidectomy using an electrothermal device originally devised to seal vessels in abdominal operations, with the conventional open Milligan-Morgan procedure performed with diathermy. SUMMARY BACKGROUND DATA: Hemorrhoidectomy is one of the most commonly performed anorectal operations. Two well-established methods, the "open" Milligan-Morgan excision and the "closed" Ferguson technique, both carry risks of postoperative bleeding, urinary retention, and late anal stenosis. The convalescence is similarly long and difficult after both operations. The quest for an improved technique of radical excision of hemorrhoids is justified. METHODS: In this case-control study, two groups of patients were alternatively allocated into study and control groups. In the study group (n = 40), an electrothermal system was used. The tissue fusion produced by this device consists of melting of collagen and elastin. This technique essentially achieves a sutureless closed hemorrhoidectomy. The operative time, postoperative complications, and time off work were compared with the group undergoing conventional Milligan-Morgan hemorrhoidectomy (control group, n = 40). RESULTS: The operative time and time off work were significantly shorter in the study group. There were also fewer postoperative complications in this group. CONCLUSIONS: The "tissue-welding" properties of this device and the shape of the electrode handpiece may be successfully applied to the performance of an operation most appropriately described as a "modified sutureless closed hemorrhoidectomy." This pilot study shows that this new technique is simple and safe, significantly shortens the operation, and is followed by a significantly easier and shorter recovery.

Adult↗