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Biomedical subjects

B Seifert

Publications and source records attributed to B Seifert.

At least 127 records · Page 7Linked to original sources
PubMed1995

Prediction of iron deficiency in chronic inflammatory rheumatic disease anaemia.

We prospectively studied 45 anaemic patients (37 women, 8 men) with chronic inflammatory rheumatic diseases. The combination of serum ferritin and CRP (as well as ESR) in its predictive capacity for bone marrow iron stores was examined. The relationship between other iron-related measurements (transferrin, transferrin saturation, soluble transferrin receptor, erythrocyte porphyrins and percentage of hypochromic/microcytic erythrocytes) and bone marrow iron stores was also investigated. Stainable bone marrow iron was taken as the most suitable standard to separate iron-deficient from iron-replete patients. 14 patients (31%) were lacking bone marrow iron. Regression analysis showed a good correlation between ferritin and bone marrow iron (adjusted R2 = 0.721, P < 0.0001). The combination of ferritin and CRP (ESR) did not improve the predictive power for bone marrow iron (adjusted R2 = 0.715) in this cohort of patients with low systemic inflammatory activity. With respect to the bone marrow iron content the best predictive cut-off value of ferritin was 30 micrograms/l (86% sensitivity, 90% specificity). The other iron-related parameters both individually and when combined were less powerful in predicting bone marrow iron than ferritin alone. Only zinc bound erythrocyte protoporphyrin in combination with ferritin slightly improved prediction (adjusted R2 = 0.731). A cut-off point of 11% hypochromic erythrocytes reached a high specificity (90%), but was less sensitive (77%).

Adult↗
PubMed1995

Immobilization of heparin on polylactide for application to degradable biomaterials in contact with blood.

The poly-(D, L-lactide) RESOMER R208 (Boehringer-Ingelheim, Germany) was modified with heparin to improve the blood contacting properties of the material. The immobilization of herapin was carried out by covalent binding with glutaraldehyde as the coupling agent. The reaction conditions, such as temperature and time, were varied to optimize the binding of heparin. The efficiency of the immobilization was monitored with respect to the total amount of coupled herapin with a toluidine blue assay and the anticoagulant activity of immobilized heparin with a factor Xa assay. The hemocompatibility of the modified polylactide was estimated after blood-material contact by the activation of platelets measured with an enzyme immuno assay for GMP140. Immobilization at ambient temperature and a reaction time of 2 h resulted in maximal heparin binding, high anticoagulant activity, and low thrombogenicity. Since the remaining unsaturated aldehyde groups of the coupling agent may cause a low hemocompatibility of the material, washing of the heparinized polylactide was carried out with ethanol. However, it was shown that washing diminished the anticoagulant activity of heparin and increased the thrombogenicity. The prolonged storage of heparinized polylactide in phosphate buffered saline for 8 days demonstrated that small quantities of heparin were released but the hemocompatibility was further improved, indicated by an increasing anticoagulant potential and a decrease in platelet activation with incubation time. A comparison of polylactide, heparinized polylactide, polypropylene, and Pellethane with respect to platelet activation by GMP140 assay and scanning electron microscopy, revealed that the heparinization of polylactide substantially improved the hemocompatibility of RESOMER R208, making the material comparable to Pellethane.

Anticoagulants↗
PubMed1995

Muscle strength assessment in polymyositis and dermatomyositis evaluation of the reliability and clinical use of a new, quantitative, easily applicable method.

OBJECTIVE: To evaluate the feasibility and the reliability of a quantitative method of maximal isometric strength measurement for the assessment of patients with myositis in clinical practice and research. METHODS: Three observers independently examined the strength of 13 muscle groups of 7 patients with stable polymyositis and dermatomyositis (PM/DM) using a handheld pull-gauge. Reliability was assessed following a balanced random 3-way cross classification with interactions and using the analysis of variance method. Serial followup strength data for 2 patients were compared to change in creatinine kinase (CK) levels. RESULTS: All measurements could be performed without causing pain to the patients. One single test including 13 muscle groups was done in 7 min or less. Both intra and interobserver correlations were strong and significant for all muscle groups. The intraobserver reliability ranged from 0.88 for elbow extensors to 0.98 for knee extensors and cervical spine flexors. The interobserver reliability ranged from 0.81 for elbow flexors to 0.98 for knee extensors and cervical spine flexors. The followup of 2 cases yielded moderate to strong correlations of serial strength measurements with CK levels. CONCLUSION: Serial measurement of isometric muscle strength with a handheld pull-gauge is a feasible, inexpensive, time efficient and reliable method and may provide additional quantitative information in the clinical assessment of patients with myositis.

Adult↗
PubMed1995

Continuous non-invasive blood pressure monitoring by brachial artery displacement method in high-risk surgical patients.

Continuous non-invasive blood pressure (CNBP) measurements were compared to invasive radial artery pressure recordings in 26 patients with cardiac, vascular and/or pulmonary disease. Patients were studied during general anaesthesia (n = 6), regional anaesthesia (n = 10), or combined technique (n = 10) for abdominal or transurethral surgery. CNBP was obtained from a cuff placed around the upper arm and simultaneously compared to invasive pressure from the ipsilateral radial artery. A CNBP device (7001 Cortronic) used intermittent oscillometric measurement for calibration. Through a cuff continuously inflated to a pressure of 20 mmHg, a microprocessor-controlled electro-pneumatic acquisition system sensed displacements of the brachial artery wall. Amplified, digitally converted, filtered and transformed data were displayed as a continuous pulse pressure waveform and digital pressure values on the screen. The CNBP method functioned without disturbances before surgery in all patients. Intra-operative use of electrocautery or a spontaneous occurrence of warning on the screen repeatedly triggered oscillometric recalibration, hence CNBP measurements were discontinued in nine patients. Coefficients of correlation (r) of all invasive and CNBP pairs (n = 1111) were 0.68, 0.58 and 0.70 for systolic, diastolic, and mean blood pressures, respectively. Prediction errors (bias, mean +/- SD) were -13.6 +/- 22.5 mmHg (on average CNBP < invasive pressure) for systolic, +13.0 +/- 12.4 mmHg (CNBP > invasive pressure) for diastolic and +5.0 +/- 13.9 mmHg (CNBP > invasive pressure) for mean CNBP, as compared to radial artery pressure values. Absolute errors (precision) were 25.3 +/- 9.4 mmHg for systolic, 17.4 +/- 4.5 mmHg for diastolic, and 13.9 +/- 4.6 mmHg for mean CNBP. During anaesthesia induction (n = 672) the difference between consecutive measurements (trend of pressure changes) with invasive and CNBP method exceeded 20 mmHg in 90 (13.3%) instances for systolic, in 33 (4.9%) instances for diastolic, and in 45 (6.6%) instances for mean blood pressure. In conclusion, the CNBP method by brachial artery wall displacement failed to measure the blood pressure reliably and to display the trend of pressure changes correctly during anaesthesia induction. In its present form this CNBP method should not replace invasive blood pressure monitoring in high-risk patients neither for anaesthesia induction nor during non-thoracic surgical procedures.

Abdomen↗
PubMed1994

Assisted circulation without systemic heparinization.

The need for improvements in materials and equipment for extracorporeal circulation has been obvious for years. Among the surfaces with biologically active compounds, those with heparin binding have been found sufficiently thromboresistant and particularly suitable for different types of artificial perfusion. Partial left heart bypass (LHBP) was performed in 10 anesthetized, acutely instrumented, and open-chested mongrel dogs (weight 23 to 50 kg) with a servo-controlled roller pump. The pump flow was maintained at 50 mL/kg/min for 6 hours. Heparin surface-coated equipment was used without additional heparin. For LHBP with a standard circuit, the total amount of heparin during the study period was (mean +/- SD) 487 +/- 124 IU/kg. The right atrial, pulmonary artery, and left ventricular end-diastolic pressures, cardiac output, left ventricular output, right and left ventricular stroke work, pulmonary gas exchange, and acid-base balance changed similarly with both systems. Blood loss (204 +/- 78 v 1,240 +/- 586 mL, P < 0.0005), volume substitution requirements (647 +/- 48 v 1,860 +/- 764 mL, P < 0.0025), and oxygen extraction ratio (mean 25.4 to 32.0 v 25.4 to 56.4%, P < 0.025) were significantly lower, and mean aortic pressure (mean 65 to 69 v 62 to 38 mmHg, P < 0.025) and hemoglobin concentration (mean 9.1 to 8.1 v 9.4 to 3.9 g/dL, P < 0.05) were significantly higher during 6 hours of LHBP without systemic heparinization. Low but stable oxygen delivery was provided with heparin-coated LHBP, whereas it showed a descending trend (mean 14.0 to 10.8 v 13.4 to 5.5 mL/kg/min, P < 0.1) with the standard circuit.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Determination of kidney function in patients with ovarian cancer treated with chemotherapy: calculation versus measurement of creatine clearance].

In patients with ovarian cancer receiving chemotherapy we compared the creatinine clearance measured in the usual way with the calculation of the creatinine clearance according to the formulas of Jelliffe and Cockroft. Regression analysis only showed a moderate correlation, whereas the analysis of the data by ROC curves allows the use of these formulas as screening tests with acceptable values of sensitivity and false-positive rate. Therefore, in the majority of these patients, collecting urine over 24 h before starting chemotherapy is no longer necessary.

Adult↗
PubMed1993

Common allergenic structures in hazelnut, rye grain, sesame seeds, kiwi, and poppy seeds.

Allergy to kiwi, poppy seeds, and/or sesame seeds often occurs in patients with a simultaneous sensitization to nuts and flour. Previously cross reactions have been verified by RAST inhibition. In this study the nature of this cross-reactivity is further characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), followed by immunoblotting to nitrocellulose. The degree of cross-reactivity among kiwi, sesame seeds, poppy seeds, hazelnuts, and rye grain was found to be very high in the patients studied. The existence of both cross-reacting and unique components was observed; however, the cross-reacting and unique components could be different for different patients.

Adolescent↗
PubMed1992

Intratracheal N-acetylcysteine use in infants with chronic lung disease.

To evaluate the effect of intratracheal administration of N-acetylcysteine (Mucomyst) on the clinical status, pulmonary function and gas exchange in premature infants with chronic lung disease, we conducted a randomized, placebo-controlled, crossover trial. Ten mechanically ventilated infants (gestational age 27 +/- 1 week; postnatal age 22 +/- 6 days) with clinical and radiological evidence of chronic lung disease and increased airway secretion were enrolled in the study. Each infant received tracheal administration of 5% N-acetylcysteine for one week and saline placebo every 4 h for another week. N-acetylcysteine was associated with a 59 +/- 26% increase in total airway resistance by the third day of treatment (p less than 0.01). A two-fold increase in airway resistance associated with an increased frequency of bradycardia and cyanosis spells was seen in two of the infants following three days of N-acetylcysteine administration, with a rapid improvement in their condition when subsequently switched to saline. Overall, N-acetylcysteine administration had no effect on the variables measured. We conclude that intratracheal administration of N-acetylcysteine to liquefy airway mucus neither improves the clinical condition nor hastens recovery in premature infants with chronic lung disease and its administration may lead to increased total airway resistance and cyanotic spells. The present data do not support the use of N-acetylcysteine as a mucolytic agent in premature infants with chronic lung disease.

Acetylcysteine↗
PubMed1991

Development of the rabbit retina. IV. Tissue tensility and elasticity in dependence on topographic specializations.

A method is introduced for the quantification of specific compliance and the elasticity of small pieces of living retinal tissue. These pieces are fixed at their margins by means of tissue glue, and loaded with a small iron spherule the bending force of which can be gradually enhanced by the action of an electromagnet. Retinal bending caused by such calibrated forces is measured by a horizontal light microscope, and used for estimations of specific compliance and elasticity of the tissue. Three different particular regions of the rabbit retina--periphery, visual streak, and (prospective) medullary rays--were tested at several post-natal developmental stages. From very early stages on (day 2 p.p.) up to adulthood the peripheral retina was found to be significantly more tensile than the two other central regions. This can be shown to depend greatly on the thickness of the tissue which is lower in the retinal periphery. During early post-natal development, all retinal regions except the (prospective) medullary rays become thinner. The tensility of the tissue increases, with the exception of the medullary rays which reduce their compliance strongly. In the adult retina, however, the tensility of all retinal regions is reduced as compared with the neonatal tissue. This seems to be caused by a constant gradual increase of the elasticity of the retina during development which, in turn, may be caused by several developmental parameters, e.g. the formation of synapses, the outgrowth of glial side branches ensheathing neighbouring neuronal cells, or a reduction in extracellular clefts. It is proposed that these differences in tensility between different retinal regions, may be the cause for differential retinal expansion driven by the intraocular pressure. Thus, simple mechanical features of the tissue may contribute to the formation of important topographic specializations of the retina, e.g. the visual streak as the site of highest visual acuity.

Aging↗
PubMed1991

Clinical and physiological responses to prolonged nasogastric administration of doxapram for apnea of prematurity.

We hypothesized that enteral doxapram would effectively treat apnea of prematurity without the appearance of major side effects. Of 16 infants, 10 (BW 1,520 +/- 102 g) received doxapram alone and 6 (BW 1,020 +/- 35 g) received doxapram plus theophylline. Apneas decreased from 16.7 +/- 1.9 to 2.1 +/- 0.6 in infants receiving doxapram alone, and from 38.2 +/- 4.4 to 7.9 +/- 2.2 apneas/24 h in those receiving doxapram plus theophylline. This was associated with an increase in alveolar ventilation, a shift of the ventilatory response to CO2 to the left, and no change in the immediate ventilatory response to 100% oxygen. Side effects included premature teeth buds corresponding to the lower central incisors, prevalence of occult blood in stool and necrotizing enterocolitis. The findings suggest that doxapram effectively controls apnea when given enterally, but should be used cautiously because of potentially harmful side effects.

Apnea↗
PubMed1990

[Determination of prolactin concentration in endometrium in the histologically normal secretory phase and in delayed transformation].

Endometrial biopsies of 92 infertile women were histologically investigated. In 46 cases the endometrium was in-phase. We found tissue prolactin by RIA examination of the endometrium on day 15 of the menstrual cycle and later. A plateau of the prolactin tissue concentration was seen between the 20th and 26th day of the cycle. A marked increase of the hormone concentration is seen at the end of the luteal phase. The endometrial prolactin tissue content was characterized by a large individual variation. A luteal phase defect was observed in 40 cases. There was a later rise of tissue prolactin concentration decreasing in contrast to the normal luteal phase at the end of the cycle. The difference was statistically significant at day 20, 26 and 28 of the menstrual cycle. Six biopsies were not included in the study. The estimation of endometrial prolactin in the late luteal phase appears to be an additional diagnostic test in case of a luteal phase-defective endometrium.

Biopsy↗
PubMed1990

[Introduction and results in the endoscopic treatment of extrauterine pregnancy].

After having applied endoscopic treatment of ectopic pregnancy for one year we herein report on 50 patients who were treated either by laparoscopy (in 20 cases) or laparotomy (in 30 cases). Conservative endoscopic surgery was performed in 12 cases (9 salpingotomy, 2 endoscopic restoration, 1 partial resection of the ovary) while conservative surgical methods by laparotomy were applied in 13 cases (8 milk out, 3 milk out with fimbrioplasty, 1 salpingotomy, 1 partial resection of the ovary). Partial endoscopic salpingectomy was necessary in 8 cases. Out of the women with laparotomy management 4 underwent an adnexectomy and 13 a salpingectomy. After laparoscopic treatment of ectopic pregnancy two patients developed an intrauterine pregnancy and in one case an ectopic pregnancy was observed again. In the laparotomy-group no intrauterine or ectopic pregnancy recurred in the period under review. There was no complication after laparoscopic management of ectopic pregnancy. However a temperature above 38 degrees C occurred in 5 cases after laparotomy caused by local inflammation or by post-operative infiltration. After endoscopic salpingostomy patency of the fallopian tubes was proofed by hysterosalpingography in 6 cases, and all tubes were found to be patent. Endoscopic management of ectopic pregnancy is recommended due to low post-operative morbidity rates and short time of hospitalization.

Fallopian Tube Patency Tests↗
PubMed1989

[Quantitative assessment of heliotherapy in psoriasis vulgaris in high altitude climate].

At the Davos Clinic for Dermatology and Allergy (Alexanderhausklinik), patients suffering from psoriasis were treated with natural UV irradiation over 6 weeks in 1987: the average doses applied amounted to 1.042 J/cm2 UVB (= 41.7 sunburn units (SU] and 41.511 J/cm2 UVA. These doses were far below those of artificial UV sources usually required in the treatment of psoriasis. The doses were also far below those which statistically increase the incidence of non-melanotic skin cancer.

Altitude↗
PubMed1989

Inhibition of in vitro and in vivo mast cell degranulation by Taenia crassiceps metacestodes in vitro incubation products.

In vitro released products of T. crassiceps metacestodes (TcIP) harvested from the peritoneal cavity of NMRI mice were tested for inhibitory effects on the in vitro degranulation of peritoneal mast cells (MCs) of normal mice (NMRI) and rats (Wistar) and on the in vivo degranulation of rat (Wistar) skin MCs (PCA-assay). In vitro degranulation was elicited chemically (compound 48/80, polymyxin B or the bee venom peptide, mellitin). In vivo degranulation was triggered immunologically (anaphylactic systems ovalbumin/anti-ovalbumin or Fasciola hepatica crude fluke extract antigen/serum of fluke-infected rats (Wistar]. In vitro degranulation of murine peritoneal MCs or the in vitro histamine release of rat peritoneal MCs normally induced chemically was significantly inhibited when the MCs were preincubated with the TcIP or with serum of T. crassiceps-infected NMRI mice from day 35 post infection and thereafter. In vitro degranulation of peritoneal MCs of infected mice was strongly inhibited beginning on day 10 after infection. Also in vivo degranulation of the IgE-sensitized rat skin MCs was significantly reduced by intradermal injection of the TcIP before (6, 3 and 1 h) antigen challenge and by preinjection (1 h) of serum from infected mice (day 80 p.i.)-The inhibitory effect was also demonstrated after immunoadsorption of mouse serum proteins naturally contaminating the TcIP. Heating (100 degrees C/15 min), even in the presence of 0.25 M HCl, did not suppress the inhibitory activity.

Animals↗