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D Pfeiffer

Publications and source records attributed to D Pfeiffer.

At least 73 records · Page 4Linked to original sources
PubMed1999

Comparison between a live and an inactivated vaccine against Newcastle disease in village chickens. A field study in northern Malawi.

A total of 156 chickens in two villages in Malawi were marked and sampled. One hundred and fifteen of these were vaccinated against Newcastle disease immediately after blood sampling, using the V4 heat-resistant strain applied by eye-drop in one village and the inactivated Newcavac vaccine in the other village. A second blood sample was collected 4 weeks after vaccination. The samples were examined using an indirect ELISA test kit. The titre group median ranged from 2 to 3 before vaccination. Both vaccines led to a positive immune response. Newcavac induced higher and more homogeneous titres compared with the V4 vaccine. There was also an increase in the median of the control group where V4 live vaccine had been applied. The differences between the median titres induced by V4, Newcavac and controls were statistically significant.

Animals↗
PubMed1999

Serological evidence of Chlamydia pneumoniae lipopolysaccharide antibodies in atherosclerosis of various vascular regions.

BACKGROUND: The role of Chlamydia pneumoniae in the pathogenesis of atherosclerosis has so far mainly been investigated in patients suffering from coronary heart disease; the other vascular regions have virtually been ignored. The aim of this study was to carry out a statistical survey of serological markers of a C. pneumoniae infection in patients with different patterns of atherosclerosis manifestation. PATIENTS AND METHODS: 340 patients were examined for the atherosclerotic alteration of peripheral arteries of the lower limbs, carotid arteries and coronary arteries by ultrasound scan and/or angiography. Immunoglobulin(Ig)G and IgA-rELISA were used to measure chlamydial lipopolysaccharide antibodies. Species determination was performed using the IgG micro-immunofluorescence test. RESULTS: 24.0% of atherosclerotic cases (A) and 52.3% of controls (C) were negative for C. pneumoniae lipopolysaccharide antibodies (p = 0.00002). By contrast, 45.1% of atherosclerotic cases and 16.9% of controls were positive for both IgG and IgA (p = 0.00002). The mean antibody titers of the atherosclerosis group were higher than in the control group (IgG positive xAIgG = 344, xCIgG = 272; IgG and IgA positive xAIgG = 576, xCIgG = 486 and xAIgA = 120, xCIgA = 91). Concerning atherosclerosis manifestation in various vascular regions, no significant differences were found between IgG and IgA antibody titers and prevalence. CONCLUSIONS: The results show that a persistent C, pneumoniae infection with evidence of lipopolysaccharide immunoglobulin G and A is equally associated with the atherosclerotic alteration of coronary arteries, carotid arteries and peripheral arterial occlusive disease, irrespective of the severity of atherosclerosis and with no predisposition to any particular vascular region.

Aged↗
PubMed1999

Haemostatic derangement in advanced peripheral occlusive arterial disease.

BACKGROUND: Dysbalance of the coagulation and fibrinolysis system was suspected to be a further risk factor for the progression of peripheral occlusive arterial disease (POAD). Reports on disturbed platelet function in advanced disease, however, were contradictory. Therefore, we studied haemostasis parameters and platelet function in symptomatic patients with peripheral arterial disease. METHODS: 60 peripheral arterial disease patients hospitalised for invasive diagnostic procedures were included into this comparative study. Patients were clinically stratified according to the criteria for chronic limb ischemia (grade I: n=36; grade II: n=11; grade III: n=13). Plasma fibrinogen, antithrombin III, von Willebrand factor, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) prothrombin time, and activated partial thromboplastin time were determined using standard methods. We measured flow cytometrically, the platelet activation marker P-selectin on nonstimulated, ADP- and TRAP-6-stimulated platelets. Angiographic data were assessed using the Bollinger score. RESULTS: Plasma levels of the procoagulant proteins fibrinogen (grade I: 3.7/grade II: 3.9/grade m: 4.0 g/l) and vWF (158/156/178%) increased and of antithrombin III (109/103/102%) and the PAI-1/tPA ratio (5.2/5.0/4.1) decreased with progressive disease. Highest platelet activation levels were observed in the CLI grade II subgroup. A significant correlation of disease severity was seen with the ankle-brachial pressure index (p=0.006; r=0.39) and with the Bollinger score (p=0.002; r=-0.41). CONCLUSIONS: Progressive peripheral obstructive arterial disease was associated with platelet hyper-reactivity, haemostatic dysbalance of pro- and anticoagulant proteins, and a counterregulatory increase of fibrinolytic activity. Therapeutic concepts should include these pathogenetic mechanisms.

Arterial Occlusive Diseases↗
PubMed1998

Transcatheter closure of atrial septal defect and patent foramen ovale with ASDOS device (a multi-institutional European trial).

A clinical trial was conducted to assess the feasibility, safety, and efficacy of the atrial septal defect (ASD) occlusion system for transcatheter closure of secundum ASD and patent foramen ovale (PFO) after episodes of cerebral embolism. Occlusion was attempted in 200 patients aged 1 to 74 years (mean 32). The procedure failed in 26 patients (13%); the device was retrieved through a catheter in 20 and through surgery in 6 patients. Procedure-related complications necessitating surgical removal of the device included device embolization in 2, device entrapment within the Chiari network in 1, frame fracture in 1, and perforation of atrial wall in 2. All 6 patients experienced an uneventful postoperative course. An additional 11 patients (6%) underwent surgical removal of the device during follow-up. There were 163 patients (81%) with an implanted ASD occlusion system at follow-up of from 6 to 36 months (mean 17). Thrombus formation around the device was detected by transesophageal echocardiography in 9 patients 1 to 4 weeks after implantation. One of these patients (who had a coagulation factor XII deficiency) suffered a cerebral thromboembolism. Late atrial wall perforation (5, 6, and 8 months after implantation) occurred in 3 adult patients. Infectious endocarditis developed in 2 adult patients (1%). No late device embolization and no atrioventricular valve injury occurred. An asymptomatic device frame fracture was found in 14% and frame deformity in 4% of all patients during the follow-up period of >230 patient-years. Immediately after closure, a moderate/large residual shunt remained in 8% and a small shunt in 29% of patients. After 1 year, a moderate/large shunt was present in 2% and a small one in 26% of patients. During a total follow-up of 49 patient-years, only 1 of 46 patients with PFO had a transient neurologic event after the closure. The study indicates that patients with centrally situated secundum ASD and those with PFO after cerebral embolism can be treated with this system with a high success rate and an acceptable morbidity.

Adolescent↗
PubMed1998

[Grönblad-Strandberg syndrome from the angiological viewpoint].

HISTORY AND CLINICAL FINDINGS: A 42-year-old man was admitted for treatment of peripheral vascular disease in the left leg (stage III of Fontaine). A year before he had undergone a right aortofemoral bypass operation. On admission there was stenosis of the left pelvic axis and bilateral femoral artery occlusion. In addition there were changes in the skin with abnormal folds, loss of elasticity and yellowish spots over the sides of the neck and the flexor surfaces of all large joints. In addition vision in the left eye was impaired. These findings suggested connective tissue disease involving the skin, eye and arterial system. INVESTIGATIONS: Routine haematological tests were normal as were clotting parameters. Serum concentration of GOT, GPT, gamma-GT were slightly increased. There was a dysproteinaemia with raised HDL and LDL levels. Resting electrocardiogram was normal, showing sinus rhythm and left axis deviation. The crurobrachial pressure index was clearly abnormal: 0.6 on the right and 0.5 on the left. Angiography of the pelvic and left arteries revealed long-segment femoral and partial lower-leg occlusions bilaterally. Abdominal sonography indicated diffuse parenchymal calcifications in both kidneys and angioid streaks on bilateral fundoscopy. Skin biopsy showed defects of elastic fibres and perivascular inflammatory infiltration, while capillary microscopy revealed twisting of the capillaries, most of them with normal lumen. These findings taken together indicated pseudoxanthoma elasticum (PXE) or Grönblad-Strandberg syndrome. TREATMENT AND COURSE: A thrombendarterectomy was performed on the left superficial femoral artery, after which the left popliteal artery became palpable, the pressure indices for the left leg were slightly better, and the patient was discharged home without further complications and improved leg perfusion. CONCLUSION: Possible cardiovascular involvement had to be taken into account in patients with PXE, and long-term angiological monitoring is indicated.

Adult↗
PubMed1998

Epidermal-growth-factor receptor correlates negatively with cell density in cervical squamous epithelium and is down-regulated in cancers of the human uterus.

The role of the epidermal-growth-factor receptor (EGFR) in cervical cancer is controversial, due to technical difficulties in localizing or in quantifying EGFR by homogenate assays or immunohistochemistry. Our autoradiographic approach, in combination with morphometry, allowed cell-type-specific quantification of EGFR, leading to the following observations: (i) In normal cervical epithelium, EGFR levels per cell were high in non-dividing squamous cells of the upper layers of normal epithelium, where a mitogenic function of these EGFRs can be excluded. (ii) In contrast to earlier findings in tissue homogenates, but consistent with our observation in normal cervical epithelium that cells of the proliferating strata (basal and parabasal cells) express intermediate and comparatively reduced levels of EGFR per cell, cervical cancers displayed a significant reduction both of specific EGF binding and of EGFR levels per cell as compared with normal epithelium. (iii) A significant negative correlation of cell density and EGFR number per cell was obtained. In normal cervical epithelium, cervical intra-epithelial neoplasia and invasive cervical cancer (p = 0.002). This negative correlation was most evident in normal epithelium, where large changes of cell density occur within one slide (p < 0.001). (iv) Specific EGF-binding was also significantly reduced in endometrial cancers when compared with normal endometrium. It is proposed that in uterine tissues low or intermediate levels of EGFR do not exclude their function as mediators of cell proliferation.

Autoradiography↗
PubMed1998

Transvasal closure of interatrial defects using the Babic double-umbrella occluder system.

The purpose of the study was to assess the feasibility and safety of closure of atrial septal defects and patent foramen ovale by means of a new interventional technique. Transvasal closure of ostium secundum atrial septal defect and patent foramen ovale was performed in 18 patients using an occluder system for atrial septal defects. Two patients had undergone unsuccessful direct surgical closure years before. Implantation and follow-up were controlled using radiographic views both with and without contrast injection, transthoracic and multiplane transesophageal echocardiographic imaging, color Doppler sonography, and computed tomography. The defect was closed in 16 patients using 19 procedures. Removal of the devices through the sheath was indicated in 4 patients because of placement failure. Intraprocedural complications were ventricular fibrillation in one patient and fixation of the device in Chiari's network in an additional one. During 7-26 months follow-up occluder damage was seen in two patients and perforation of the left atrium in one patient. Thickening on the occluder surface was observed in two patients. There was no death. The system for closure of atrial septal defect is feasible and safe in patients with defects < or = 27 mm in diameter. Long-term observation of outcome is limited yet.

Adult↗
PubMed1998

Low-dose flunarizine does not affect short-term fetal circulatory responses to acute asphyxia in sheep near term.

Asphyxia is one of the major causes of perinatal brain damage and neuronal cell loss, which may result in psychomotor deficits during later development. It has been shown previously that the immature brain can be protected from ischemic injury by flunarizine, a class IV calcium antagonist. However, cardiovascular side-effects of flunarizine, when applied at the dosages used in those studies, have been reported. Recently, the present authors were able to demonstrate that even by injecting flunarizine at a far lower dosage (1 mg kg-1 estimated bodyweight) neuronal cell damage, caused by occlusion of both carotid arteries for 30 min, can be reduced in fetal sheep near term. The aim of the present study was, therefore, to examine whether low-dose flunarizine affects fetal cardiovascular responses to acute asphyxia in sheep near term. Ten fetal sheep were chronically instrumented at a mean gestational age of 132 +/- 1 days (term is at 147 days). Fetuses from the study group received a bolus injection of flunarizine (1 mg kg-1 estimated fetal weight) 60 min before asphyxia, whereas the solvent was administered to the fetuses from the control group. Organ blood flows, physiological variables and plasma concentrations of catecholamines were measured before, during and after a single occlusion of uterine blood flow for 2 min (i.e. at 0, 1, 2, 3, 4, and 30 min). Before asphyxia, the distribution of combined ventricular output and physiological variables, as well as concentrations of catecholamines, in fetuses from the control group were in the normal range for chronically prepared fetal sheep near term. During acute asphyxia there was a redistribution of cardiac output towards the central organs accompanied by a pronounced bradycardia and a rapid increase in arterial blood pressure. After asphyxia circulatory centralization did not resolve quite as rapidly as it developed, but was almost completely recovered at 30 min after the insult. There were nearly no differences in the time course of physiological and cardiovascular variables measured before, during and after acute intrauterine asphyxia between the control and study groups. From the present study it was concluded that low-dose flunarizine does not affect short-term fetal circulatory responses to acute asphyxia in sheep near term.

Adrenal Glands↗
PubMed1998

Acute and long-term effects of consecutive radiofrequency applications on conduction properties of the subeustachian isthmus in type I atrial flutter.

INTRODUCTION: Bidirectional conduction block at the subeustachian isthmus predicts long-term efficacy of atrial flutter ablation. Limited data are available on the incidence and outcome of minor conduction changes such as unidirectional or incomplete block. This prospective study sought to systematically assess discrete acute and long-term alterations of bidirectional conduction prior to a complete conduction block. METHODS AND RESULTS: In 41 patients with type I atrial flutter, pulse propagation through the subeustachian isthmus during low lateral and proximal coronary sinus pacing was documented and analyzed following each consecutive radiofrequency (RF) application. In cases of altered conduction properties and noninducibility of atrial flutter, patients were followed-up for 12 months. Three sets of results were found. First, following RF application, 23 patients presented a progressive conduction delay prior to a complete conduction block. Second, RF application did not always affect counterclockwise and clockwise conduction simultaneously or to the same extent. In 13 patients, an initial alteration of counterclockwise conduction was present before an alteration of clockwise conduction; in 5 patients, clockwise conduction was primarily affected. Third, the recurrence rate of typical atrial flutter was 9% (2/22) in patients with a complete bidirectional conduction block, 54% (7/13) in patients with unidirectional conduction block, and 100% (6/6) in patients with sole bidirectional conduction delay. CONCLUSION: In 50% of the patients, consecutive RF applications resulted primarily in a progressive conduction delay rather than a sudden conduction block. Since counterclockwise and clockwise conduction were not always affected simultaneously or to the same extent, lateral as well as septal pacing is recommended for improvement of bidirectional conduction block. Normalization of primarily altered conduction and, therefore, recurrence of atrial flutter are high in all patients without bidirectional block.

Adult↗
PubMed1997

Catecholamine detection using enzymatic amplification.

Different amplification sensors based on the substrate recycling principle were investigated with respect to their applicability to catecholamine detection. In the bioelectrocatalytic approach, glassy carbon electrodes were modified by laccase or a PQQ-dependent glucose dehydrogenase. Substrate recycling occurs and the detection limit is in the lower nanomolar concentration range (e.g. 10 nM dopamine and 1 nM noradrenaline for the laccase- and glucose dehydrogenase-modified electrodes, respectively). Combinations of glucose dehydrogenase with laccase or tyrosinase were investigated as bienzymatic probes. Among the systems we studied, the laccase/glucose dehydrogenase sensor is the most sensitive (detection limit: 0.5 nM adrenaline). The selectivities of the different sensor systems are discussed. Application of the laccase/glucose dehydrogenase electrode in different media (i.e. brain homogenate, heart effluate) was successfully shown. For samples with high concentrations of interfering substances (uric and ascorbic acid), the interferences can be effectively removed using enzymatic methods.

Biosensing Techniques↗
PubMed1997

Quantitative determination of the epidermal growth factor receptor in cervical cancer and normal cervical epithelium by 2-color flow cytometry: evidence for down-regulation in cervical cancer.

Expression of epidermal growth factor receptor (EGFR) was quantified by 2-color flow cytometry in cervical cancer (n = 73) and normal cervical epithelium (n = 11). EGFR was determined using a murine monoclonal EGFR antibody, and number of bound antibodies was quantified adding calibration beads with defined antigenic binding sites. Tumor cells were identified by simultaneous DNA staining. Epithelium of normal cervical tissue was detected by labeling for cytokeratin. Results were compared with EGFR quantification by autoradiography on cryostat sections using a radioligand binding assay. A high degree of correlation was found between the 2 methods. In cervical carcinomas 14,600 binding sites/cell (median; range, 160-283,000 binding sites/cell) were detected, considerably less compared with normal cervical squamous epithelium, which was 30,700 binding sites/cell (median; range, 19,900-44,000 binding sites/cell). This finding clearly contrasts with other reports of enhanced EGFR expression in cervical cancer. The discrepancy may be explained by contamination of tissue homogenates used for radioligand or enzyme immunosorbent assays by non-epithelial tissue elements with low or absent EGFR expression. Interference with quantitative EGFR determination in epithelial cells may result in false low estimates of EGFR expression predominantly in normal cervical tissue. This should be avoided by identifying tumor and normal epithelial cells prior to analysis. In our study, 63% of cervical cancers expressed low levels of EGFR compared with normal cervical epithelium, and only 10% showed overexpression. There is evidence that cervical carcinomas overexpressing EGFR represent a small, but biologically distinct group of cervical cancers exhibiting enhanced aggressiveness associated with poor survival of the patients.

Antibodies, Monoclonal↗