Long-QT syndrome-associated caveolin-3 mutations differentially regulate the hyperpolarization-activated cyclic nucleotide gated channel 4.

Background Caveolin-3 (cav-3) mutations are linked to the long-QT syndrome (LQTS) causing distinct clinical symptoms. Hyperpolarization-activated cyclic nucleotide channel 4 (HCN4) underlies the pacemaker current If. It associates with cav-3 and both form a macromolecular complex. Methods To examine the effects of human LQTS-associated cav-3 mutations on HCN4-channel function, HEK293-cells were cotransfected with HCN4 and wild-type (WT) cav-3 or a LQTS-associated cav-3 mutant (T78M, A85T, S141R, or F97C). HCN4 currents were recorded using the whole-cell patch-clamp technique. Results WT cav-3 significantly decreased HCN4 current density and shifted midpoint of activation into negative direction. HCN4 current properties were differentially modulated by LQTS-associated cav-3 mutations. When compared with WT cav-3, A85T, F97C, and T78M did not alter the specific effect of cav-3, but S141R significantly increased HCN4 current density. Compared with WT cav-3, no significant modifications of voltage dependence of steady-state activation curves were observed. However, while WT cav-3 alone had no significant effect on HCN4 current activation, all LQTS-associated cav-3 mutations significantly accelerated HCN4 activation kinetics. Conclusions Our results indicate that HCN4 channel function is modulated by cav-3. LQTS-associated mutations of cav-3 differentially influence pacemaker current properties indicating a pathophysiological role in clinical manifestations.

[Measuring the contrast-enhancement in the skin and subcutaneous fatty tissue with the NMR-MOUSE: a feasibility study]. / Messung der Kontrastmittelanreicherung in der Haut und im subkutanen Fettgewebe mit der NMR-MOUSE -- eine Machbarkeitsstudie.

PURPOSE: The NMR-MOUSE is an open and mobile sensor for measuring NMR relaxation parameters in organic matters. T1-measurements of the subcutaneous fatty tissue and the skin are reported. MATERIAL AND METHOD: For the first time, the NMR-MOUSE was employed to measure the signal recovery following saturation of the skin and the subcutaneous fatty tissue of three patients, before and after administering a contrast agent. RESULTS: Despite a low signal-to-noise ratio, changes in the relaxation behaviour of the skin could be detected. Malignant tissue exhibits faster signal recovery than scar tissue and healthy tissue, which only show a small difference. CONCLUSIONS: Changes in the relaxation behavior can be monitored with the NMR-MOUSE. Before the clinical use of the NMR-MOUSE, sensitivity, sensor mounting device, and sensor tuning must be improved. Further investigations need to be performed on a statistically relevant number of patients.

[Portable NMR-MOUSE: a new method and its evaluation of the Achilles tendon]. / Mobile NMR-MOUSE: eine neue Methode und erste Anwendung an der Achillessehne.

AIM: The increased demands placed on the Achilles tendon in recreational and professional sports have led to a rise in pathological changes in this anatomic region. Magnetic resonance evaluations of the tendon have proven to be a valid but expensive and stationary diagnostic tool. In this study, a new mobile NMR sensor was to be tested in the evaluation of the Achilles tendon. METHOD: The technical development of the so-called NMR-MOUSE ( Mobile Universal Surface Explorer) represents a novelty with an open and portable sensor. To appraise its diagnostic efficacy, healthy athletes (professional soccer players, track and field, as well as aquatic athletes), healthy controls and patients with Achilles tendon lesions were evaluated. As an accessible, sensitive and reproducible parameter for the study the transverse relaxation time T2 with its angular dependency was chosen. As part of the examination, the relaxation times of the skin, the tendon and the surrounding soft tissue were determined. RESULTS: During the evaluation with the NMR-MOUSE, the skin and peritendineous tissue exhibited relatively long T2 relaxation times, while the tendon itself had significantly shorter T2 times, allowing for a clear differentiation of the structures. The T2 relaxation time of the Achilles tendon in the control group averaged 5.8 ms. The MRI-MOUSE was able to demonstrate an increase in the T2 relaxation times in patients with pathological lesions of the tendon due to the increased water retention of the tissue. CONCLUSION: The novel NMR-MOUSE represents a cost efficient and portable sensor, which allows for a reliable evaluation of surface structures, such as the Achilles tendon. The anisotropic structure of the tendon and the surrounding soft tissue can be reliably differentiated with the help of the NMR-MOUSE.

Persistence of virus and viral genome in myocardium after coxsackievirus B3-induced murine myocarditis.

Following infection with Coxsackievirus B3 (CVB3), A-strain mice develop ongoing myocarditis that persists after the virus ceases to be cultivatable from heart tissue. We studied the natural history of this virus-induced but apparently autoimmune inflammation by means of in situ hybridization (ISH) and by polymerase chain reaction (PCR). Both ISH and culture allowed detection of virus up to 2 weeks post-infection in virtually all heart tissues. In contrast, PCR revealed the presence of viral genome for a substantially longer period of time, i.e. at least 34 days after CVB3 infection. Similarly, the majority of mice showed myocardial inflammation at this time point. However, the persistence of virus did not correlate with ongoing myocarditis, and vice versa. Most mice with ongoing myocarditis produced heart myosin autoantibodies, most probably as a result of tissue damage. The lack of correlation between presence of ongoing inflammation and persistence of virus supports our previous view that the late phase of CVB3-induced myocarditis is mediated by autoimmunological mechanisms.

Early diagnosis of gastric lymphoma: gene rearrangement analysis of endoscopic biopsy samples.

The diagnosis of gastric lymphoma in endoscopic biopsy specimens remains difficult despite the emergence of accepted criteria for the histologic diagnosis of lymphomas originating from mucosa-associated lymphoid tissue (MALT). The sensitivity and validity of immunoglobulin (Ig) gene rearrangement analysis of mucosal biopsies for the diagnosis of malignant B-cell lymphoma were investigated in comparison with conventional histology and immunohistology. Biopsy specimens from 34 different endoscopies of 20 patients with a previous history, or tentative diagnosis of gastric lymphoma, and 12 control samples were analyzed for the presence of clonal Ig gene rearrangements. A clonal B-cell population was detected by Southern blot analysis in all patients with a definitive histologic diagnosis of lymphoma. In addition, in two patients the detection of clonal rearrangements in biopsy specimens preceded by several months the histologic diagnosis of lymphoma, and clonality was confirmed in three further patients where histology remained inconclusive. In some cases of low-grade MALT-lymphoma, discrete spreading of malignant cells within chronically inflamed mucosa was suggested by the presence of identical clonal rearrangements in all simultaneously obtained biopsies, with or without histologically detectable involvement by lymphoma. Our results show that immunoglobulin gene rearrangement studies of endoscopic biopsy samples are an additional powerful tool for the diagnosis of gastric lymphoma, especially for detecting early recurrence, and improve the preoperative assessment of the extent of mucosal involvement.

Detection of enteroviral ribonucleic acid in myocardial biopsies from patients with idiopathic dilated cardiomyopathy by polymerase chain reaction.

Infection by enteroviruses, especially by Coxsackie B viruses, has been incriminated in pathogenesis of dilated cardiomyopathy. We developed polymerase chain reaction tests for the detection of enteroviral and Coxsackie B3 genomes, respectively, in myocardial biopsies obtained from a homogeneous group of 19 patients with idiopathic dilated cardiomyopathy. To determine unambiguously the incidence of enteroviruses and Coxsackie B3 viruses in these patients, we used two primer pairs, one common to all enteroviruses and the other specific for Coxsackie B3 viruses. In six patients of the dilated cardiomyopathy group, enteroviral ribonucleic acid (RNA) could be detected; only one was subspecified as Coxsackie B3 RNA. In contrast, no enteroviral RNA could be detected in a contrast group of 21 patients with other cardiac disorders. These results suggest that enteroviruses other than Coxsackie B3 are causally linked to the pathogenesis of dilated cardiomyopathy.

Immunoglobulin gene rearrangement in plasma cell dyscrasias: detection of small clonal cell populations in peripheral blood and bone marrow.

The bone marrow (BM) and peripheral blood (PB) samples of 71 patients with plasma cell dyscrasias were analysed by the Southern blot technique for the presence of clonal immunoglobulin (Ig) gene rearrangements. 53% of BM samples examined were archival material such as air dried BM slides or frozen trephine biopsies. The results were related to bone marrow plasmacytosis as determined by cytology and flow cytometry, and other clinical parameters. Clonal Ig gene rearrangements were found in BM samples of 45 (83%) of 54 MM patients and in 3 of 6 patients with monoclonal gammopathy of unknown significance (MGUS). Clonal cell populations in the PB were detected in 11 (30%) of 37 examined MM patients, but in none of the patients with MGUS or solitary plasmacytoma of bone. PB involvement was associated with progressive disease. Circulating monoclonal cells were significantly associated with higher M-protein levels (p < 0.05). Thus, circulating clonal precursor cells are encountered more frequently in active MM.

[Mitochondria number as a prognostic parameter in dilated cardiomyopathy. A long-term follow-up study]. / Die Mitochondrienzahl als prognostischer Parameter bei dilatativer Kardiomyopathie. Eine Langzeitstudie.

According to morphological criteria of the myocardium, patients with clinical and hemodynamic signs of dilated cardiomyopathy were divided into three groups. Group I: patients with 1-2 mitochondria per 2 sarcomeres (n = 46); Group II: patients with more than 2 mitochondria per 2 sarcomeres (n = 47); Group III: patients with histological findings of myocarditis in the past (n = 33). Mean follow-up in groups I, II, III was 29, 22, 26 months, respectively (6-58, 3-52, 3-62/median 29, 18, 22). Clinical parameters were evaluated at the beginning and at the end of the prospective observation and were classified clinically as "improved, unchanged, deteriorated"; "heart transplantation", "death of cardial causes", "death of other than cardial causes" or "lost to follow up" were the other endpoints of the observation. At the beginning there were no hemodynamic differences between groups I, II, III, except significant difference in ejection fraction and mean ventricular shortening velocity between groups I and II. Scored together with the clinical symptoms "deterioration" and "death of cardial causes" as endpoints, survival rates without event up to 5 years in group I were 83 +/- 7% compared with group II 33 +/- 13% and group III 86 +/- 8%. There were significant differences (p less than 0.01). We conclude that the increased number of mitochondria per 2 sarcomeres in biopsy specimen of patients with dilated cardiomyopathy can be a significant parameter of deteriorated prognosis.

[Changes in the catecholamine plasma level 3 months after aortocoronary bypass operation]. / Anderung der Katecholamin-Plasmaspiegel 3 Monate nach aortokoronarer Bypass-Operation.

Plasma catecholamine levels were obtained during diagnostic heart catheterization from the pulmonary artery and aorta and, similarly, renin levels were determined in the pulmonary artery in 31 patients with coronary heart disease and 18 normal controls. 3 months after aorto-coronary bypass surgery the patients with coronary heart disease underwent repeat heart catheterization and the epinephrine, norepinephrine and renin levels were compared with those obtained before operation. Norepinephrine decreased in the aorta from (means +/- SEM) 475 +/- 57 pg/ml to 360 +/- 38 pg/ml (p less than 0.001) postoperatively (controls 225 +/- 21 pg/ml). Epinephrine decreased from 121 +/- 11 pg/ml to 108 +/- 16 pg/ml (p less than 0.001) postoperatively (controls 84 +/- 9 pg/ml). This shows that postoperative relief from myocardial ischemia is associated with normalization of the preoperatively elevated plasma catecholamine levels).

[Clinical, hemodynamic and morphologic findings in dilated cardiomyopathy]. / Klinische, hämodynamische und morphologische Befunde bei dilatativer Kardiomyopathie.

45 patients (39 men, six women), mean 41 (19-63) years of age with clinical, angiographic and morphologic diagnosis of dilated cardiomyopathy were evaluated in respect of three morphologic classes. Two groups of patients without signs of previous myocarditis were formed, with one-to-two mitochondria per two sarcomeres (group Ia, n = 19), or with more than two mitochondria per two sarcomeres, respectively (group Ib, n = 14); and one group with signs of previous myocarditis (group II, n = 12). The mean relative mitochondrial volume fraction in relation to myofibril volume fraction was significantly lower in group Ia (33 +/- 4/67 +/- 4%) compared to group Ib (39 +/- 5/61 +/- 5%) (p less than 0.01). Mean values of group II (36 +/- 6/64 +/- 6%) were in between the two other groups. Left ventricular enddiastolic pressure (18 +/- 11, 18 +/- 8, 16 +/- 10 mm Hg), pulmonary vascular resistance (473 +/- 414, 406 +/- 205, 458 +/- 495 dyn x s x cm-5), ejection fraction (36 +/- 21, 32 +/- 16, 28 +/- 16%), endsystolic volume index (131 +/- 82, 127 +/- 66, 132 +/- 60 ml/m2), enddiastolic volume index (187 +/- 81, 176 +/- 62, 181 +/- 63 ml/m2), dp/dt max (1951 +/- 875, 1737 +/- 575, 1741 +/- 478 mmHg x s-1) and mean VCF (0.76 +/- 0.58, 0.44 +/- 0.32, 0.54 +/- 0.39 s-1) showed no significant differences between the three groups. Follow-up of the patients in the three groups to median 19, 22, 24 months, respectively, after biopsy, showed an improvement of the clinical findings, especially concerning the groups with one-to-two mitochondria only and with signs of previous myocarditis, but no difference in survival within the three groups. For the individual case our morphologic parameters seem to be without predictive value.

[Plasma catecholamine level in diagnostic heart catheterization studies]. / Katecholamin-Plasmaspiegel während diagnostischer Herzkatheteruntersuchung.

Plasma catecholamine levels were obtained during diagnostic heart catheterization from pulmonary artery and aorta before and after injection of contrast medium in 31 patients with coronary heart disease and in 18 normals. The most striking difference between both groups is a significant decline of norepinephrine concentration in aortas after injection of contrast medium in the normals (from 296 +/- 24 [mean +/- SEM] to 225 +/- 21 pg/ml [p less than 0.01]) and no change in patients with coronary heart disease. The cause seems to be rather increased elimination than a decrease of secretion of norepinephrine. Adrenalin shows only partially similar results. Further studies will have to show, what could be the reason for these different reactions of catecholamine level in normals and in patients with coronary heart disease.

[Cardiokymography: relative quantification of results in normal probands]. / Kardiokymographie: Relative Quantifizierung der Ergebnisse bei Normalpersonen.

The main problem with cardiokymography (CKG) and the principal reason for its limited clinical application to date is the deficiency of calibration and quantification of results. We tried to improve the value of the procedure by quantification of the results in 14 healthy young men (age: 23, 18-31 years) in place of subjective assessment. Before and after a bicycle exercise stress test CKG tracings were obtained in a lying position at rest, immediately after exercise and after recovery. Two different methods were applied to quantify the CKG tracings (distance method and area method). The relative height of the curves at rest was 89 +/- 72% (68 +/- 39%), immediately after exercise 111 +/- 60% (73 +/- 27%) and, after recovery 121 +/- 88% (78 +/- 49%). The relative change in the height of the curves between rest and exercise was not significant according to both methods (+22 +/- 64%/+5 +/- 32%), but the variation of values in an individual patient between rest and exercise was large. Interobserver variability was rather large, according to two independent investigators. Hence, it was not possible to establish limits of normal values in quantitative CKG, but only mean values.

[Comparison of methods for the relative quantification of the hump in cardiokymographic tracings]. / Methodenvergleich zur relativen Quantifizierung des Buckels kardiokymographischer Registrierungen.

Exercise stress testing in a sitting position was carried out preoperatively and three months post aortocoronary bypass surgery in 125 men. Before exercise, immediately after exercise and after 5 minutes of recovery cardiokymography (CKG) was performed in a lying position. So called "bulges" in the CGK-tracings, defined as Type I, II or III registration by non quantitative judgement so far, were set out quantitatively by evaluation of area (Flächen-method) or distance (Distanzmethod) of the bulge. We found a significant increase (p less than 0.001) of bulges according to both methods after exercise but no difference between rest and after recovery concerning the area method. The distance method showed higher values (p less than 0.05) after recovery than at rest. All mean values postoperatively were not significantly lower than the corresponding values preoperatively. Our results show, that CKG-tracings can be quantitatively assessed both by the area or by the distance method. The latter is easier to apply and has comparable results to the area method.

[Late complications following Björk-Shiley and Carpentier-Edwards heart valve replacements]. / Spätkomplikationen nach Björk-Shiley- und Carpentier-Edwards-Herzklappenersatz.

Valve related and valve induced, fatal or non fatal complications after Björk-Shiley valve replacement (n = 50) are compared with complications following Carpentier-Edwards valve replacement (n = 113). These patients had been operated upon between 1976 and 1982 and were followed up until 1985. Estimated actuarial cumulative survival following Carpentier-Edwards valve replacement (53 +/- 12% after a 100-month period) did not differ significantly from the estimate following Björk-Shiley valve replacement (80 +/- 6% after a 100-month-period), and subgroups of the cohort did not differ in survival after Carpentier-Edwards or Björk-Shiley valve replacement either. However, the estimate of actuarial cumulative event-free survival following Carpentier-Edwards valve replacement in patients under 40 years of age (46 +/- 14% after a 92-month period) was significantly worse (p less than 0.05) than with Björk-Shiley valves (100 +/- 0% after a 92-month period), (n = 30). The leading cause of clinical complications following Carpentier-Edwards valve replacement was a demonstrable degeneration of the bioprosthesis in 12 cases. The diagnosis of degeneration was established a mean of 73 months postoperatively (range 42-101 months).