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Biomedical subjects

A Franke

Publications and source records attributed to A Franke.

At least 73 records · Page 4Linked to original sources
PubMed2001

Evaluation of septal hypertrophy and systolic function in diseases that cause left ventricular hypertrophy: a 3-dimensional echocardiography study.

OBJECTIVES: The goals of this study were to determine regional systolic function of the septum and to relate it to regional wall thickness and wall stress. BACKGROUND: Wall thickening, a parameter of systolic function, is determined by wall thickness and wall stress. In patients with hypertrophic obstructive cardiomyopathy (HOCM), hypertrophic nonobstructive cardiomyopathy (HNCM), and hypertensive heart disease (HHD), regional systolic function of normal and hypertrophic septal regions has been incompletely characterized by 2-dimensional echocardiography. Thus, multiplane transesophageal echocardiography with 3-dimensional reconstruction of the septum was used. METHODS AND RESULTS: In 49 patients (15 controls, 11 with HOCM, 8 with HNCM, and 15 with HHD) 4 parallel (2 basal and 2 apical) equidistant short-axis cross sections from base to apex were obtained from the reconstructed septum. In each short-axis cross section, 6 wall-thickness measurements were made in 15 degrees intervals at end diastole and end systole, for a total of 48 measurements in each patient. Fractional thickening was calculated as wall thickening divided by end-diastolic wall thickness. Wall thickness of the basal cross sections was significantly thicker (P < .001) in HOCM and HNCM than in HHD. However, circumferential wall thickness was more evenly distributed in HNCM and HHD when compared with HOCM. In the basal cross sections, fractional thickening was similarly reduced in all hearts, though basal wall stress was significantly different in all groups (P < .001). In the apical cross sections, wall thickness was similar in all diseased hearts, but fractional thickening was better (P < .001) and wall stress lower (P < .001) in HNCM than in HOCM and HHD. CONCLUSIONS: In septal regions without or with only mild hypertrophy, regional systolic function is preserved and appears to be determined by hemodynamic factors such as wall stress. However, in regions with moderate to severe hypertrophy, systolic function is markedly and uniformly impaired in all groups, which seems not to be caused by differences in wall thickness and wall stress but by the degree of the myocardial disease process.

Cardiomyopathy, Hypertrophic↗
PubMed2001

Alterations of cell-mediated immunity following cardiac operations: clinical implications and open questions.

Cardiac surgery with cardiopulmonary bypass (CPB) is known to induce an immune response whose nature has been increasingly elucidated during the recent decade. Clinically, patients usually show two to three of the four symptoms, which define the so-called systemic inflammatory response syndrome (SIRS). In addition, all parameters of the innate, nonspecific immune system, e.g., polymorphonuclear cells, elastase, and complement, are activated. This also applies to the proinflammatory mediators interleukin (IL)-1beta, -6, and -8, and tumor necrosis factor (TNF)-alpha. Within the adaptive, specific immune system, a decrease of T lymphocytes and T helper (TH) cells is observed, whereas suppressor/ cytotoxic T cells and B cells appear to be nearly unaffected. Cytokine measurements provide more detailed information: IL-2 and IL-12, which are important for the activation of the type-1 TH-cell (TH1)-mediated immune response, are depressed following cardiac operation. In contrast, IL-10 and transforming growth factor-beta essential to TH2-mediated humoral or anti-inflammatory immune response, are upregulated. In vivo tests, e.g., delayed type hypersensitivity skin reaction and tetanus antibody production, confirm the polarization of the adaptive immune response towards the TH2 pathway. However, all these alterations usually do not result in clinical adverse events. Therefore, more information is needed about the immune response of patients at high preoperative risk or with serious perioperative complications to find out whether clinically relevant events are correlated to alterations of immune response. For this purpose, more readily available, standardized methods for immunologic monitoring appear highly desirable.

Cardiac Surgical Procedures↗
PubMed2001

Combined effects of well-done red meat, smoking, and rapid N-acetyltransferase 2 and CYP1A2 phenotypes in increasing colorectal cancer risk.

Heterocyclic amines (HAAs) are suspected carcinogens that are formed in meat when it is cooked at high temperature for long durations. These compounds require metabolic activation by CYP1A2 and N-acetyltransferase (NAT) 2 or NAT1 before they can bind to DNA. It has been hypothesized that well-done meat increases the risk of colorectal cancer (CRC), especially in individuals with the rapid phenotype for CYP1A2 and NAT2. This association may be particularly strong in smokers because smoking is known to induce CYP1A2. We conducted a population-based case-control study on Oahu, Hawaii to specifically test this hypothesis. An in-person interview assessed the diet and preference for well-done red meat of 349 patients with CRC and 467 population controls. A urine collection after caffeine challenge and a blood collection were used to assess phenotype for CYP1A2 and NAT2 and genotype for NAT2 and NAT1, respectively. No statistically significant main effect association with CRC was found for red meat intake, preference for well-done red meat, the NAT2 rapid genotype, the CYP1A2 rapid phenotype or the NAT1*10 allele. However, in ever-smokers, preference for well-done red meat was associated with an 8.8-fold increased risk of CRC (95% confidence interval, 1.7-44.9) among subjects with the NAT2 and CYP1A2 rapid phenotypes, compared with smokers with low NAT2 and CYP1A2 activities who preferred their red meat rare or medium. No similar association was found in never-smokers, and there was no increased risk for well-done meat among smokers with a rapid phenotype for only one of these enzymes or for smokers with both rapid phenotypes who did not prefer their red meat well-done. These data provide additional support to the hypothesis that exposure to carcinogens (presumably HAAs) through consumption of well-done meat increases the risk of CRC, particularly in individuals who are genetically susceptible (as determined by a rapid phenotype for both NAT2 and CYP1A2) and suggest that smoking, by inducing CYP1A2, facilitates this effect.

Aged↗
PubMed2000

Echocardiographic evidence of hemodynamic and clinical improvement in patients paced for heart failure.

Dilated cardiomyopathy is frequently associated with electrical conduction disturbances. Development of left bundle-branch block with discoordinated ventricular contraction pattern further contributes to impaired hemodynamic performance. Biventricular pacing has evolved as a new treatment option for patients with dilated cardiomyopathy and conduction disturbances. The "electrical" approach aims to normalize the disturbed contraction pattern, thereby improving hemodynamic function by simultaneous stimulation at different ventricular sites. Acute hemodynamic improvement with biventricular pacing has been demonstrated in patients with depressed left ventricular function and delayed intraventricular conduction. Due to the variations in optimal pacing site and atrioventricular delay, individual optimization to achieve optimal hemodynamic benefit is necessary. Echocardiography has the potential to provide hemodynamic data by Doppler techniques and combine these with geometric information about ventricular volumes, ejection fraction, and contraction patterns. This article focuses on the use of echocardiographic techniques for noninvasive optimization in cardiac pacing and presents preliminary experience from the initial trials on multisite pacing in heart failure.

Arrhythmias, Cardiac↗
PubMed2000

Assessment of myocardial reperfusion by intravenous myocardial contrast echocardiography and coronary flow reserve after primary percutaneous transluminal coronary angioplasty [correction of angiography] in patients with acute myocardial infarction.

BACKGROUND: This study investigated whether the extent of perfusion defect determined by intravenous myocardial contrast echocardiography (MCE) in patients with acute myocardial infarction (AMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) relates to coronary flow reserve (CRF) for assessment of myocardial reperfusion and is predictive for left ventricular recovery. METHODS AND RESULTS: Twenty-five patients with first AMI underwent intravenous MCE with NC100100 with intermittent harmonic imaging before PTCA and after 24 hours. MCE before PTCA defined the risk region and MCE at 24 hours the "no-reflow" region. The no-reflow region divided by the risk region determined the ratio to the risk region. CFR was assessed immediately after PTCA and 24 hours later. Left ventricular wall motion score indexes were calculated before PTCA and after 4 weeks. CFR at 24 hours defined a recovery (CFR >/=1.6; n=17) and a nonrecovery group (CFR <1.6; n=8). Baseline CFR did not differ between groups. MCE ratio to the risk region was smaller in the recovery group compared with the nonrecovery group (34+/-49% vs 81+/-46%, P=0.009). A ratio to the risk region of </=50% defined an MCE reperfusion group. It was associated with improvement of CFR from 1.67+/-0.47 at baseline to 2. 15+/-0.53 at 24 hours (P<0.001) and of regional wall motion score index from 2.6+/-0.5 to 1.9+/-0.5 at 4 weeks (P<0.001). CONCLUSIONS: Intravenous MCE can be used to define perfusion defects after AMI. Assessment of microcirculation by MCE corresponds to evaluation by CFR. Serial intravenous MCE has the potential to identify patients likely to have improved left ventricular function after AMI.

Aged↗
PubMed2000

[Imaging techniques in cardiology: three-dimensional echocardiography].

UNLABELLED: Three-dimensional echocardiography offers new opportunities for clinical cardiology and the solution of scientific questions. Data acquisition is possible using different techniques: (1) Realtime 3D echocardiography with matrix-array transducers is the most promising approach, but is still limited by several difficulties; (2) 3D reconstruction is based on a number of sequentially acquired 2D image planes (like in multiplane TEE), which are put together afterwards. There are 2 ways of data analysis. 1. Morphological analysis. Surface rendering of the endocardial border can create perspectives not achievable with conventional methods such as the "en face" view of atrial septal defects or the atrial view of the mitral valve. Prolapsing leaflets and the spatial relationship can be identified much easier than using 2D methods. In complex congenital heart disease 3D echo may provide better spatial orientation and easier communication with the cardiothoracic surgeons. 2. Quantitative analysis of volumes, masses, and surfaces is only possible after manual contour tracing with several cut planes generated from the 3D data set. This procedure is time consuming and limits the use in clinical routine, even though validation studies demonstrated that 3D echo determination of masses and volumes is superior to one- or two-dimensional techniques which are based on geometric assumptions. Furthermore, quantitative 3D analysis has a unique pre- and postinterventional diagnostic potential. FUTURE PERSPECTIVES: Combination with color Doppler data may lead to a more precise quantitation of valve regurgitations. Improvements of hard- and software will allow faster acquisition, reconstruction, and quantitative analysis. Assessment of regional myocardial perfusion may be possible in combination with left heart contrast agents. CONCLUSION: 3D echocardiography allows perspectives not achievable conventionally and has a great potential for precise quantitative and reproducible analysis of cardiac morphology which overcomes the limitations of 2D echocardiography.

Angiography↗
PubMed2000

[Improved endocardial border delineation during dobutamine stress echocardiography using the left heart contrast medium BY 963].

UNLABELLED: The interpretation of induced wall motion abnormalities during dobutamine stress echocardiography is affected in the case of impaired image quality. In 48 consecutive patients (mean age 62 +/- 9 years, 32 males, 16 females) with suspected coronary disease undergoing coronary angiography, the transpulmonary contrast agent BY 963 was given i.v. as bolus during dobutamine stress echocardiography (10-40 micrograms kg min, plus max. 1 mg atropine) to analyze improvements in endocardial border delineation. For each of the 16 segments of the left ventricle, the endocardial border delineation was evaluated. Using BY 963 the average number of non-evaluable segments decreased by 58% from 5.2% to 2.2% at rest (p = 0.008) and by 56% from 5.9% to 2.6% at maximal stress (p = 0.003) as compared to the non-contrast study for all patients. In patients with impaired image quality, defined as at least 1 non-evaluable segment at rest without contrast enhancement (N = 14), the number of non-evaluable segments decreased from 19.2% to 8.2% (p = 0.004) at rest and from 19.2% to 9.6% (p = 0.006) at maximal stress. The greatest decrease of non-evaluable segments was seen in the lateral and anterior segments of the apical views (maximum of 80%). The improved endocardial border delineation resulted in an improved agreement between two observers in the interpretation of the dobutamine stress echocardiograms as positive or negative (kappa = 0.38 without contrast, kappa = 0.58 with contrast). Contrast application resulted in a slight improvement of diagnostic accuracy of dobutamine stress echocardiography in the detection of angiographically proven significant coronary artery disease. CONCLUSION: In patients with impaired endocardial border delineation the use of the echo contrast agent BY 963 reduces the number of non-evaluable segments. Improvement of endocardial delineation is greatest for lateral and anterior segments in the apical views.

Aged↗
PubMed2000

A novel translocation (17;19)(p13;p13) in a patient with acute myelomonocytic leukemia.

We report on a patient with acute myeloid leukemia (AML M4) and a so far unrecorded translocation (17;19). The leukemia transformed from a myeloproliferative disorder (MPD) and showed a progressive fatal course. Following transformation, all leukemic cells showed an apparently balanced translocation (17;19)(p13;p13). The breakpoint regions harbor genes such as TP53 (17p13) and E2A, ENL, or LYL1 (19p13), which could be relevant in leukemogenesis. We suspect that the translocation (17;19)(p13;p13) may be a prognostic factor for transformation from chronic MPD to acute leukemia.

Chromosome Banding↗
PubMed2000

Dosage compensation rox!

Recent advances in our understanding of dosage compensation in flies have centered on characterizing its sex-specificity, identifying the structural RNAs involved in the process, and determining how dosage compensation is targeted to particular sites on the X chromosome.

Animals↗
PubMed2000

Three-dimensional reconstructions of normal and aneurysmatic left ventricles in vivo using transesophageal echocardiography.

OBJECTIVE: To perform three-dimensional surface reconstructions to provide spatial delineations of a normal and an aneurysmatic left ventricle, using transesophageal echocardiography. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Eight patients in cardiogenic shock admitted to the intensive care unit and two patients undergoing surgery with general anesthesia. INTERVENTIONS: Using a multiplane transesophageal echocardiography probe, nine echocardiographic cross-sectional images of the heart at approximately 20 degrees angular increments were obtained from midesophageal level in each patient for three-dimensional surface reconstructions. Multiple determinations of cardiac output using the thermodilution principle were also made in each patient to verify the accuracy of three-dimensional data sets. MEASUREMENTS AND MAIN RESULTS: End-diastolic and end-systolic volumes were determined from three-dimensional data sets using the disc-summation method. Stroke volume was derived as the difference between end-diastolic and end-systolic volumes. Stroke volume was also calculated from thermodilution cardiac output measurements and heart rate. Correlation and limits of agreement between stroke volumes derived by the two methods were determined. Three-dimensional wire-frame models of a normal and an aneurysmatic left ventricle at end-systole were constructed from the nine echocardiographic cross-sectional images. Correlation coefficient between stroke volume derived from three-dimensional data sets using the disc-summation method and that measured by the thermodilution method was 0.91 (p < 0.001). Wire-frame models reveal a normal symmetric cavity and an aneurysmal cavity in sharp relief. CONCLUSIONS: Three-dimensional surface reconstruction can be performed from multiple cross-sectional images obtained using an unmodified commercially available multiplane transesophageal echocardiography probe, to reveal the left ventricular cavity in sharp relief. High correlation between stroke volume calculated from three-dimensional data sets and that measured by the thermodilution method attests to the accuracy of the three-dimensional data sets.

Adult↗
PubMed2000

Rapid quantification of left ventricular function and mass using transoesophageal three-dimensional echocardiography: validation of a method that uses long-axis cutplanes.

AIMS: Despite its proven superiority compared to conventional echocardiographic techniques, three-dimensional (3D) echocardiography has not gained widespread acceptance in clinical medicine for the quantification of left ventricular volumes, function and mass. This is mainly due to the large, time-consuming process of data analysis. We sought to validate a new method that enables the accurate quantification of the left ventricle in a clinically acceptable short period of time. METHODS AND RESULTS: Left ventricular volumes, ejection fraction and mass were determined in 44 patients using 3D echocardiography. The 3D echocardiographic data sets were analysed: (i) using the conventional 'summation of slices' algorithm (slice thickness 5 and 10mm), which is based on the analysis of the 3D reconstructed left ventricle in short-axis cross-sections; and (ii) using the new method which is based on the analysis of the 3D reconstructed left ventricle in long-axis images. In each patient measurements were repeated using 3, 6, 7, 8, 9, 12 and 15 long-axis images. For all volumetric measurements there was a continuous reduction of measurement variability using increasing numbers of long-axis images. The use of more than nine long-axis images for volumes, and eight long-axis images for ejection fraction and mass, did not result in a further reduction of variability. The analysis time for volumes and masses averaged less than 5 min for the long-axis method using nine component images, compared to 20-43 min for the short-axis method. CONCLUSION: 3D echocardiography combined with a novel method based on the analysis of long-axis cross-section allows accurate quantification of left ventricular volumes, function and mass in a clinically acceptable short period of time. In the future, the combination of a real-time 3D echocardiographic acquisition technique with this analysis method should have important implications for the introduction of 3D echocardiography in clinical practice.

Echocardiography, Three-Dimensional↗
PubMed2000

Rosai-Dorfman disease and generalized AA amyloidosis: a case report.

We report on a patient who, at 31 years of age, was found to suffer from sinus histiocytosis with massive lymphadenopathy (SHML; Rosai-Dorfman disease) with nodal and extranodal involvement as described previously. Five years later the patient presented with nephrotic syndrome caused by a generalized AA amyloidosis, and he subsequently died from pulmonary thromboembolism owing to renal vein thrombosis. Retrospective analysis of serum levels of C-reactive protein (CRP) showed that during the last 3 years before his death, he had a persistently elevated CRP level ranging from 73 to 161 mg/L, despite antiinflammatory treatment with prednisolone, methotrexate, or 6-mercaptopurine. These figures indicate that the patient was probably suffering from a permanent acute phase response which, in the absence of any other evidence of a chronic inflammatory disease which commonly causes AA amyloidosis, was most likely owing to SHML.

Adult↗
PubMed2000

Long-term efficacy of radon spa therapy in rheumatoid arthritis--a randomized, sham-controlled study and follow-up.

OBJECTIVE: To quantify the efficacy of a series of baths containing natural radon and carbon dioxide (1.3 kBq/l, 1.6 g carbon dioxide/l on average) versus artificial carbon dioxide baths alone in patients with rheumatoid arthritis. SUBJECTS: Sixty patients participating in an in-patient rehabilitation programme including a series of 15 baths were randomly assigned to two groups. DESIGN: Pain intensity (100 mm visual analogue scale) and functional restrictions [Keitel functional test, Arthritis Impact Measurement Scales (AIMS questionnaire)] were measured at baseline, after completion of treatment and 3 and 6 months thereafter. To investigate whether the overall value of the outcomes was the same in both groups, the overall mean was analysed by Student's t-test for independent samples. RESULTS: The two groups showed a similar baseline situation. After completion of treatment, relevant clinical improvements were observed in both groups, with no notable group differences. However, the follow-up revealed sustained effects in the radon arm, and a return to baseline levels in the sham arm. After 6 months, marked between-group differences were found for both end-points (pain intensity: -16.9%, 95% confidence interval -27.6 to -6.2%; AIMS score: 0.57, 95% confidence interval 0.16 to 0.98). The between-group differences were statistically significant for both overall means (pain intensity, P: = 0.04; AIMS, P: = 0.01). CONCLUSION: Marked short-term improvements in both groups at the end of treatment may have masked potential specific therapeutic effects of radon baths. However, after 6 months of follow-up the effects were lasting only in patients of the radon arm. This suggests that this component of the rehabilitative intervention can induce beneficial long-term effects.

Aged↗
PubMed2000

Non-contrast second harmonic imaging improves interobserver agreement and accuracy of dobutamine stress echocardiography in patients with impaired image quality.

OBJECTIVE: To examine the influence of second harmonic imaging during dobutamine echocardiography on regional endocardial visibility, interobserver agreement in the interpretation of wall motion abnormalities, and diagnostic accuracy in patients with reduced image quality. DESIGN: Blinded comparison. SETTING: Tertiary care centre. PATIENTS: 103 consecutive patients with suspected coronary artery disease and impaired transthoracic image quality (>/= 2 segments with poor endocardial delineation). METHODS: Fundamental and second harmonic imaging were performed at each stage of a dobutamine stress echocardiography. Coronary angiography was undertaken within three weeks of dobutamine echocardiography in 75 patients. MAIN OUTCOME MEASURES: Evaluation of regional endocardial visibility (scoring from 0 = poor to 2 = good) and of segmental wall motion abnormalities for both modalities separately. A second blinded examiner analysed 70 studies to determine interobserver agreement. RESULTS: Mean (SD) visibility score for all segments was 1.2 (0.4) using fundamental imaging and 1.7 (0.2) using second harmonic imaging at rest (p < 0.001), and 1.1 (0.4) v 1.6 (0.3), respectively, at peak dobutamine dose (p < 0.001). The average number of segments with poor endocardial visibility was lower for second harmonic than for fundamental imaging (0.6 (1.1) v 3.8 (2.6) at rest, p < 0.001; 0.9 (1.3) v 4.3 (2.9) at peak dose, p < 0.001). Improvement was most pronounced in all lateral and anterior segments. The kappa value for identical study interpretation increased from 0. 40 to 0.69 (p < 0.05). Sensitivity for the diagnosis of coronary artery disease was 64% using fundamental imaging versus 92% using harmonic imaging (p < 0.001), while specificity remained unchanged at 75% for both imaging modalities. CONCLUSIONS: Second harmonic imaging enhances endocardial visibility during dobutamine echocardiography. Consequently, interobserver agreement on stress echocardiography interpretation and diagnostic accuracy are significantly improved compared to fundamental imaging. Thus, in difficult to image patients, dobutamine echocardiography should be performed using second harmonic imaging.

Cardiotonic Agents↗
PubMed2000

[Acupuncture massage vs Swedish massage and individual exercise vs group exercise in low back pain sufferers--a randomized controlled clinical trial in a 2 x 2 factorial design].

OBJECTIVE: Rehabilitation programs for low back pain (LBP) almost always contain massage and exercise therapy in one form or another. AIM: This study aimed to quantify the effectiveness of therapeutic 'Acupuncture' massage (APM; i.e. tonic stimulation of entire meridians) according to Penzel versus Swedish massage (SM) and individual medical exercises (IE) versus group exercises (GE) in LBP sufferers. PATIENTS AND METHODS: 109 patients participating in a complex in-patient rehabilitation program were randomised to four groups in a 2 x 2 factorial design. Main outcome measures were functional ability/disability (Functional Questionnaire Hanover, FFbH) and pain intensity (10 cm visual analogue scale, VAS). Pre/post changes were evaluated by means of 2-way analysis of variance (ANOVA). Additionally, lumbar motility was measured by a 2-inclinometer technique. RESULTS: Baseline mean FFbH score was 66 (SD = 18)%, mean pain intensity on VAS was 4.5 (SD = 2.4) cm. Lumbar flexion and extension were 49 (13) and 13 (7). Because of some differences between groups at baseline, group-standardized outcomes were used for analysis. APM showed beneficial effects for both disability and pain compared with SM (group differences: delta FFbH 7.0% [95% confidence interval (CI) 2.5-11.6], p = 0.003; delta VAS 0.8 cm [95% CI: 2-15], p = 0.024). Standardized response means were SRMFFbH = 0.5 and SRMVAS = 0.8 for APM, as opposed to SRMFFbH = -0.01 and SRMVAS = 0.4 for SM. Neither significant group differences between both exercise groups [delta FFbH -0.5% (95% CI -5.2 to 4.2); delta Vas 0.4 cm (95% CI 0.3 to 1.1)] nor significant interactions between medical exercise and massage were found. CONCLUSIONS: Given the fact that even the treatments considered to be the best available achieve at best moderate effects, the observed effect sizes with APM are promising and warrant further investigation in replication studies. In contrast to common view, no superiority of individual versus group exercises could be found in the present study.

Acupuncture Therapy↗