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Biomedical subjects

C Bartels

Publications and source records attributed to C Bartels.

At least 19 recordsLinked to original sources

The foot-and-mouth disease epidemic in The Netherlands in 2001.

An outbreak of foot-and-mouth disease (FMD) in Great Britain was reported on 21 February 2001, followed by an outbreak of FMD in The Netherlands a month later. This Dutch index outbreak occurred on a mixed, veal-calf/dairy-goat farm in Oene, in the central part of The Netherlands. The most-likely route of infection was the import of Irish veal-calves to this Dutch herd via an FMD-contaminated staging point in France. With hindsight, more herds seemed to be infected by the time the index outbreak was confirmed. The regular EU control measures were implemented, in combination with pre-emptive culling of herds within 1km of each outbreak. Nevertheless, more outbreaks of FMD occurred. Most of the virus infections on those farms were "neighborhood infections". Because the situation seemed out of control locally and the destruction capacity became insufficient, it was decided to implement an emergency vaccination strategy for all biungulates in a large area around Oene to stop further spread of the virus. All susceptible animals on approximately 1800 farms in this area were vaccinated. All farms subsequently were depopulated, starting from 2 weeks after vaccination. In total, 26 outbreaks were detected (the last outbreak on 22 April 2001). In total, approximately 260,000 animals were killed.

Animals↗

Risk factors for clinical Salmonella enterica subsp. enterica serovar Typhimurium infection on Dutch dairy farms.

Risk factors for outbreaks in 1999 of clinical Salmonella enterica subsp. enterica serovar Typhimurium infection on dairy farms were studied in a matched case-control study with 47 case farms and 47 control farms. All 47 case farms experienced a clinical outbreak of salmonellosis which was confirmed with a positive bacteriologic culture for serovar Typhimurium in one or more samples. Serovar Typhimurium phage type 401 and 506 (definitive type 104, DT104) were the most frequently isolated phage types (13 isolates). On most farms (66%), clinical signs were seen only among adult cows. The most frequently reported clinical signs were diarrhoea (in 92% of the farms) and depression (in 79% of the farms). Control farms were matched on region and had no history of salmonellosis. A questionnaire was used to collect data on case and control farms. The relationship between serovar Typhimurium status of the farm and possible risk factors was tested using conditional logistic regression. Significant factors in the final model were presence of cats on the farm (OR=0.06), purchase of manure (OR=21.5), feeding colostrum only from own dam (OR=0.08), a non-seasonal calving pattern (OR=25), unrestricted grazing of lactating cows (OR=0.07), and a high mean mowing percentage of pasture (OR=1.02).

Animals↗

Does histocompatibility affect homograft valve function after the Ross procedure?

BACKGROUND: Homograft valves have been shown to be immunogenic, but it is unknown whether this affects valve function. Therefore, we prospectively studied the degree of histoincompatibility (defined as the number of human leukocyte antigen [HLA] mismatches between valve donor and recipient) and the response of the recipient (measured by antibodies against HLA) in relation to echocardiographic parameters of homograft valve function after the Ross procedure. METHODS AND RESULTS: Twenty-six patients (mean age 41+/-14 years; 20 males, 6 females) and the cryopreserved pulmonary homograft valves that were implanted during a Ross procedure were typed for HLA-A, HLA-B, and HLA-DR. After a mean follow-up of 15+/-6 months, 14 (54%) of the patients were anti-HLA class I antibody positive. In all but 1 patient, these antibodies were shown to be donor specific. During follow-up, there was a significant increase of the maximal (+6.2+/-7.1 mm Hg) and mean (+3.2+/-4.3 mm Hg) transhomograft pressure gradients but not of homograft regurgitation. Neither the number of HLA mismatches nor antibody status was found to have significant impact on homograft valve function. In a multivariate analysis, smaller homograft size (P=0.001) and younger recipient age (P=0.044) were shown to be significantly associated with increased transhomograft pressure gradients. CONCLUSIONS: Implantation of a cryopreserved pulmonary homograft during the Ross procedure can induce a specific humoral response. We observed a significant increase of the transhomograft pressure gradients within 15+/-6 months after surgery. For this period, we were unable to demonstrate a relationship between this increase and the degree of histoincompatibility.

Adult↗

Anti-HLA class I antibodies and pulmonary homograft function after the Ross procedure.

BACKGROUND: The Ross procedure provides excellent long-term results in the majority of patients. However, degeneration of the pulmonary homograft in some patients remains an unresolved problem that may be related to immunologic factors. Therefore, we studied the prevalence of antihuman leukocyte antigen (HLA) class I antibodies and echocardiographic results of homograft function at rest. METHODS: Forty-seven patients (37 men, 10 women; 47 +/- 15 years) were seen for echocardiography 1.1 to 63.9 months (median, 27 months) postoperatively. The presence of anti-HLA antibodies was tested against a panel of lymphocytes of 50 donors. RESULTS: Twenty-seven (57%) of the patients produced anti-HLA class I antibodies. No difference in the maximal or mean transhomograft pressure gradient, or in the frequency of homograft regurgitation according to the presence or absence of anti-HLA antibodies was found. However, the right ventricle was slightly but significantly larger in antibody-positive patients (26.3 +/- 4.2 versus 30.7 +/- 3.5 mm; p = 0.001). CONCLUSIONS: In the first years after the Ross procedure, we could not detect significant evidence of an association between anti-HLA class I antibodies and echocardiographic results of homograft function at rest in adults.

Adult↗

Increased mortality after coronary artery bypass graft surgery is associated with increased levels of postoperative creatine kinase-myocardial band isoenzyme release: results from the GUARDIAN trial.

OBJECTIVES: We sought to determine if elevated cardiac serum biomarkers after coronary artery bypass graft surgery (CABG) are associated with increased medium-term mortality and to identify patients that may benefit from better postoperative myocardial protection. BACKGROUND: The relationship between the magnitude of cardiac serum protein elevation and subsequent mortality after CABG is not well defined, partly because of the lack of large, prospectively studied patient cohorts in whom postoperative elevations of cardiac serum markers have been correlated to medium- and long-term mortality. METHODS: The GUARD during Ischemia Against Necrosis (GUARDIAN) study enrolled 2,918 patients assigned to the entry category of CABG and considered as high risk for myocardial necrosis. Creatine kinase-myocardial band (CK-MB) isoenzyme measurements were obtained at baseline and at 8, 12, 16 and 24 h after CABG. RESULTS: The unadjusted six-month mortality rates were 3.4%, 5.8%, 7.8% and 20.2% for patients with a postoperative peak CK-MB ratio (peak CK-MB value/upper limits of normal [ULN] for laboratory test) of < 5, > or = 5 to <10, > or =10 to < 20 and > or =20 ULN, respectively (p < 0.0001). The relationship remained statistically significant after adjustment for ejection fraction, congestive heart failure, cerebrovascular disease, peripheral vascular disease, cardiac arrhythmias and the method of cardioplegia delivery. Receiver operating characteristic curve analysis revealed an area under the curve of 0.648 (p < 0.001); the optimal cut-point to predict six-month mortality ranged from 5 to 10 ULN. CONCLUSIONS: Progressive elevation of the CK-MB ratio in clinically high-risk patients is associated with significant elevations of medium-term mortality after CABG. Strategies to afford myocardial protection both during CABG and in the postoperative phase may serve to improve the clinical outcome.

Aged↗

Influence of modified ultrafiltration on coagulation, fibrinolysis and blood loss in adult cardiac surgery.

OBJECTIVES: Modified ultrafiltration (MUF) significantly reduce blood loss and transfusion requirements in pediatric cardiac surgery presumably by a reduction in inflammatory mediators which decrease the inflammatory axes and decrease the cross-activation of fibrinolysis and thrombosis. The influence of MUF on blood loss and homologous blood transfusion in adult cardiac surgery has not yet been determined. Furthermore, data about the influence on routine coagulation tests, platelet activation as well as the coagulation and fibrinolytic systems are limited. METHODS: In a prospective randomized study 48 patients scheduled for elective myocardial revascularization were randomized into a control group (n=16), a conventional ultrafiltration (CUF) group (n=16) and a MUF group (n=16). Perioperatively, serial blood samples were drawn at specific intervals to evaluate coagulation, fibrinolysis, and platelet function. RESULTS: Neither the coagulation nor the fibrinolytic system was positively influenced by MUF or CUF. The routine clotting tests were comparable except for a significantly higher antithrombin III activity after MUF compared to the CUF control group persisting 24 h postoperatively. Platelet factor 4 activity and platelet counts showed no differences among the groups. MUF considerably reduced the postoperative blood loss (MUF, 6.4+/-1.7 ml/kg bw per 24 h vs. CUF, 9.2+/-2.5 ml/kg bw per 24 h (P=0.003) vs. control, 8.9+/-2.2 ml/kg bw per 24 h (P=0.008)) and allogeneic blood transfusion (MUF, 2.0+/-3.4 ml/kg bw per 24 h vs. CUF, 6.9+/-5.1 ml/kg bw per 24 h (P=0.034) vs. control, 7.0+/-6.3 ml/kg bw per 24 h (P=0.029)). CONCLUSIONS: MUF in adult cardiac surgery significantly reduces postoperative blood loss and transfusion requirements. The mechanism for reduced blood loss could not be elucidated in this study.

Antithrombin III↗

Outcome after mild-to-moderate blunt head injury: effects of focal lesions and diffuse axonal injury.

PRIMARY OBJECTIVE: A comparison of the effects of focal and diffuse axonal injury in mild-to-moderate traumatic brain injury (TBI). RESEARCH DESIGN: In a prospective longitudinal study of 138 consecutive patients suffering from TBI who were admitted to the Magdeburg University Hospital, 60 could be assessed neuropsychologically 8--31 days after trauma and 18--45 weeks later. METHODS AND PROCEDURES: GCS, CT-analysis, comprehensive neuropsychological assessment. MAIN RESULTS: The initial GCS-score was significantly correlated with outcome impairments of semantic fluency and memory in the Wechsler Similarities and in two clinical scales (Neurobehavioural Rating Scale, Frontal Lobe Score). The presence of CT-signs of DAI corresponded with deficits in tasks of response selection and suppression, the presence of focal contusions with results in the clinical scales, reaching significance for behavioural deficits with frontal contusions. Improvements between first and second assessments were pronounced in patients with signs of DAI. CONCLUSIONS: The data indicate that traumatic DAI results in mainly transient neuropsychological deficits. Focal frontal contusions result in more relevant deficits at outcome that affect behaviour and, thus, impair rehabilitation prognosis. It is concluded that even in clinically 'mild' TBI, prognosis and rehabilitation requirements should be established by early imaging and post-acute neuropsychological assessment.

Adolescent↗

A novel yeast U2 snRNP protein, Snu17p, is required for the first catalytic step of splicing and for progression of spliceosome assembly.

We have isolated and microsequenced Snu17p, a novel yeast protein with a predicted molecular mass of 17 kDa that contains an RNA recognition motif. We demonstrate that Snu17p binds specifically to the U2 small nuclear ribonucleoprotein (snRNP) and that it is part of the spliceosome, since the pre-mRNA and the lariat-exon 2 are specifically coprecipitated with Snu17p. Although the SNU17 gene is not essential, its knockout leads to a slow-growth phenotype and to a pre-mRNA splicing defect in vivo. In addition, the first step of splicing is dramatically decreased in extracts prepared from the snu17 deletion (snu17Delta) mutant. This defect is efficiently reversed by the addition of recombinant Snu17p. To investigate the step of spliceosome assembly at which Snu17p acts, we have used nondenaturing gel electrophoresis. In Snu17p-deficient extracts, the spliceosome runs as a single slowly migrating complex. In wild-type extracts, usually at least two distinct complexes are observed: the prespliceosome, or B complex, containing the U2 but not the U1 snRNP, and the catalytically active spliceosome, or A complex, containing the U2, U6, and U5 snRNPs. Northern blot analysis and affinity purification of the snu17Delta spliceosome showed that it contains the U1, U2, U6, U5, and U4 snRNPs. The unexpected stabilization of the U1 snRNP and the lack of dissociation of the U4 snRNP suggest that loss of Snu17p inhibits the progression of spliceosome assembly prior to U1 snRNP release and after [U4/U6.U5] tri-snRNP addition.

Amino Acid Sequence↗

Coping with illness after brain diseases--a comparison between patients with malignant brain tumors, stroke, Parkinson's disease and traumatic brain injury.

PURPOSE: This study investigates coping styles in patients suffering from different brain disorders (malignant brain tumors, stroke, Parkinson's disease and traumatic brain injury). METHOD: In a combined analysis of four prospective studies we investigated 21 patients with malignant glioma at the end radiochemotherapy, 30 patients one year after ischemic stroke, 54 patients suffering from various stages of Parkinson's disease, and 58 patients 6 to 8.5 months after traumatic brain injury. The assessment of coping with illness was based on the Freiburg Questionnaire on Coping with illness. RESULTS: With few exceptions, coping styles did not differ across the various brain pathologies. Differences occurred with respect to 'active, problem-oriented coping' (decreased in stroke patients), and coping by search for religious relief or quest for sense (increased in patients with Parkinson's disease). CONCLUSION: Differences in coping styles could be mainly related to age and social factors. Individual coping strategies seem only to be little related to the type of brain pathology.

Acute Disease↗

Association of serology with the endovascular presence of Chlamydia pneumoniae and cytomegalovirus in coronary artery and vein graft disease.

BACKGROUND: Chemotherapeutic treatment for patients with symptomatic coronary artery disease to reduce cardiovascular events may be initiated in response to elevated antibody titers against Chlamydia pneumoniae or cytomegalovirus. How antibody titers are associated with the endovascular presence of these microorganisms is still unclear. METHODS AND RESULTS: Antibody titers against C pneumoniae (microimmunofluorescence) and cytomegalovirus (ELISA) in patients undergoing primary (coronary desobliterates, n=80) or repeated CABG (occluded vein grafts, n=45) were correlated with the endovascular presence of the 2 microorganisms. C pneumoniae was detected by means of a nested polymerase chain reaction (PCR) and by culturing. Both conventional PCR and quantitative PCR were applied for detection of cytomegalovirus. C pneumoniae (PCR/culture) was detected in 19/9% (15/80 and 7/80) of coronary desobliterates and in 18/11% (8/45 and 5/45) of occluded vein grafts. There was no statistical evidence that IgG values differed between patients with or without C pneumoniae detection who were undergoing primary CABG. In contrast, repeated-CABG patients with a positive PCR (P=0.0027) or C pneumoniae culture (P=0.0018) had distinctly elevated IgG titers compared with patients in whom C pneumoniae was not detected. Cytomegalovirus could not be detected in the examined specimens. CONCLUSIONS: Cytomegalovirus infection does not seem to be associated with advanced coronary artery lesions. C pneumoniae antibody titers are not associated with the endovascular presence of C pneumoniae in patients with coronary artery disease. The observed strong association between elevated IgG titers and the detection of C pneumoniae in occluded vein grafts warrants further investigation.

Aged↗

[Intermediate term clinical results after endoaneurysmorrhaphy in left ventricular aneurysm].

Endoaneurysmorrhaphy (EAR) in postinfarct ventricular aneurysms leads to excellent short-term results. However, the temporal response of EAR is widely unknown. Thus, the indication for surgical treatment of patients with ventricular aneurysms is not well defined. EAR was performed in 157 patients (6/1993-6/1999) with symptomatic ventricular aneurysms (median NYHA III). Factors influencing cardiac mortality and morbidity during follow-up were determined by univariate and multivariate analysis. Perioperative mortality was low: 5%. Mortality during follow-up was 3.3% per year, resulting in a 5-year survival rate of 78%. NYHA classification ameliorated significantly from the preoperative status compared to the follow-up period (median NYHA II; p < 0.001). Multivariate analysis identified preexisting arterial occlusive disease and advanced age (> 70 years) as significant factors influencing medium-term mortality. Implantation of the left internal mammary artery was associated with a better survival rate. Endoaneurysmorrhaphy can be performed with low perioperative mortality, will result in a significant amelioration of the cardiac clinical status and offers low medium-term mortality. Our data indicate that EAR seems to be the procedure of choice for patients with symptomatic ventricular aneurysms.

Aged↗

Valve-sparing aortic root replacement (remodeling/reimplantation) in acute type A dissection.

BACKGROUND: High reoperation rates after supracommissural tube graft replacement for acute type A dissection due to sinus of Valsalva dilation have been reported. Valve-sparing operations focusing on the replacement of the sinus of Valsalva are an appealing alternative. The applicability of these techniques in acute type A dissection remains debatable and results are limited. METHODS: From 1992 to 1998, 20 patients with acute type A dissection received a valve-sparing aortic root replacement. Two different types of aortic valve-sparing operations were performed: the remodeling technique in 11 patients and the reimplantation technique in 9 patients. Patients were followed for 26 +/- 18 months. Echocardiographic studies were performed every 6 months. RESULTS: There were 2 early postoperative deaths and no late death, no reoperation, and no thromboembolic events. The latest echocardiographic studies of the 18 survivors showed a competent valve in 12 and a trivial aortic valve insufficiency in 6 patients. The mean aortic valve pressure gradient was 4.3 +/- 1.3 mm Hg. CONCLUSIONS: These midterm results support the surgical strategy of valve-sparing aortic root replacement in patients with acute type A dissection.

Aortic Dissection↗

Carotid endarterectomy prior to major abdominal aortic surgery.

BACKGROUND: Major aortic surgery carries a high risk of stroke. Carotid artery occlusive disease (CAOD) has been identified as one of the contributing risk factors. Regarding the long-term prevention of stroke, carotid endartectomy (CEA) seems to be superior to the best medical treatment in patients with high-grade CAOD. However, the role of CEA prior to major aortic surgery has not been studied. METHODS DESIGN: Prospective study, observational design. SUBJECTS AND SETTING: 201 patients referred to a community hospital for major aortic surgery. INTERVENTION: The patients were non-invasively screened by continuous-wave and duplex Doppler ultrasonography for the presence of CAOD. In 41 patients with angiographically confirmed high-grade CAOD, CEA was performed prior to major aortic surgery. MAIN OUTCOME MEASURE: Combined mortality and major morbidity from CEA and abdominal aortic surgery. RESULTS: There was no mortality or morbidity related to CEA. Total perioperative mortality related to major aortic reconstruction was 3.5%. No new perioperative focal neurologic deficits occurred except for one fatal stroke in a patient in whom CEA had been judged not to be indicated. CONCLUSIONS: CEA can be performed safely prior to major aortic surgery resulting in excellent overall neurologic outcome in patients with high-grade CAOD. We propose that patients scheduled for major aortic surgery be screened for the presence of high-grade CAOD and that CEA be performed first, if indicated according to published guidelines.

Adult↗

Detection of Chlamydia pneumoniae but not cytomegalovirus in occluded saphenous vein coronary artery bypass grafts.

BACKGROUND: A causal relation between atherosclerosis and chronic infection with Chlamydia pneumoniae and/or cytomegalovirus (CMV) has been suggested. Whether the unresolved problem of venous coronary artery bypass graft occlusion is related to infection with C pneumoniae and/or CMV has not been addressed. METHODS AND RESULTS: Thirty-eight occluded coronary artery vein grafts and 20 native saphenous veins were examined. Detection of C pneumoniae DNA was performed by use of nested polymerase chain reaction (PCR). Homogenisates from the specimen were cultured for identification of viable C pneumoniae. Both conventional PCR and quantitative PCR for detection of CMV DNA were applied. Differential pathological changes (degree of inflammation, smooth muscle cell proliferation [MIB-1]) were determined and correlated to the detection of both microorganisms. C pneumoniae DNA could be detected in 25% of occluded vein grafts. Viable C pneumoniae was recovered from 16% of occluded vein grafts. Except for 1 native saphenous vein, all control vessels were negative for both C pneumoniae detection and culture. All pathological and control specimens were negative for CMV DNA detection. Pathological changes did not correlate with C pneumoniae detection. CONCLUSIONS: Occluded aorto-coronary venous grafts harbor C pneumoniae but not CMV. The detection of C pneumoniae in occluded vein grafts warrants further investigation.

Adult↗

Management of porcelain aorta during coronary artery bypass grafting.

BACKGROUND: Patients with porcelain aorta carry a high risk of systemic embolism during coronary artery bypass grafting. No currently proposed surgical approach avoids manipulation of the heavily calcified ascending aorta. A novel surgical approach avoiding manipulation of the porcelain aorta was evaluated with regard to its efficacy in prevention of atheroemboli. METHODS: The following surgical protocol was performed in 23 patients with porcelain aorta: (1) arterial cannulation of the axillary artery, (2) hypothermic fibrillatory arrest for performance of the distal anastomosis, and (3) construction of the proximal anastomosis to the inominate artery or to a disease-free area of the ascending aorta during hypothermic circulatory arrest. RESULTS: The postoperative course was uneventful in all patients. No patient experienced a cerebrovascular accident or visceral organ injury as a result of atheroemboli. CONCLUSIONS: The proposed surgical approach is safe and reliable in patients with porcelain aorta and has the potential to reduce the prevalence of stroke and systemic embolization associated with coronary artery bypass grafting in patients with porcelain aorta.

Aged↗

Adjuvant treatment of deep sternal wound infection with collagenous gentamycin.

BACKGROUND: The treatment of deep sternal wound infections remains controversial. Currently advocated procedures carry the risk of reinfections. The significance of local antibiotic-releasing systems as an adjuvant therapy to avoid reinfections is the subject of the presented study. METHODS: Forty-two patients with deep sternal wound complication were treated with radical wound debridement, sternal refixation, retrosternal suction drainage, bilateral pectoralis major muscle flaps, and placement of collagenous drug carrier loaded with gentamycin (Sulmycin Implant) underneath, above, and between the sternal edges. RESULTS: No treatment failure and death were observed in our patients. Side effects after adjuvant treatment with collagenous gentamycin were not detected. CONCLUSIONS: The preliminary results of adjuvant therapy with collagenous gentamycin in combination with surgical debridement leads to excellent results in the treatment of early deep sternal wound infections with no death and no primary treatment failures. This technique is easy to perform, reliable, and safe. For final judgment controlled randomized trials are mandatory.

Aged↗

Integrality of nasalization and F1. II. Basic sensitivity and phonetic labeling measure distinct sensory and decision-rule interactions.

In vowel perception, nasalization and height (the inverse of the first formant, F1) interact. This paper asks whether the interaction results from a sensory process, decision mechanism, or both. Two experiments used vowels varying in height, degree of nasalization, and three other stimulus parameters: the frequency region of F1, the location of the nasal pole/zero complex relative to F1, and whether a consonant following the vowel was oral or nasal. A fixed-classification experiment, designed to estimate basic sensitivity between stimuli, measured accuracy for discriminating stimuli differing in F1, in nasalization, and on both dimensions. A configuration derived by a multidimensional scaling analysis revealed a perceptual interaction that was stronger for stimuli in which the nasal pole/zero complex was below rather than above the oral pole, and that was present before both nasal and oral consonants. Phonetic identification experiments, designed to measure trading relations between the two dimensions, required listeners to identify height and nasalization in vowels varying in both. Judgments of nasalization depended on F1 as well as on nasalization, whereas judgments of height depended primarily on F1, and on nasalization more when the nasal complex was below than above the oral pole. This pattern was interpreted as a decision-rule interaction that is distinct from the interaction in basic sensitivity. Final consonant nasality had little effect in the classification experiment; in the identification experiment, nasal judgments were more likely when the following consonant was nasal.

Humans↗

Successful dilatation of the small aortic root for implantation of a larger valve prosthesis.

Optimal hemodynamic performance is of paramount importance when implanting a prosthesis in a patient with a small aortic annulus. In order to avoid prosthesis size/patient body surface area mismatch, current techniques advocate aortic annulus patch enlargement or the use of a supra-annular prosthesis to ensure the implantation of an appropriately sized aortic valve. We present the first description of mechanical dilatation of a small aortic annulus as a simple alternative method.

Aged↗