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Biomedical subjects

C Fink

Publications and source records attributed to C Fink.

At least 73 records · Page 4Linked to original sources
PubMed2000

[Antegrade flow in the aorta ascendens despite aortic atresia: 2 case reports with retrograde coronary perfusion through coronary fistulas and sinusoids].

In aortic atresia, coronary perfusion normally occurs through retrograde blood flow in the ascending aorta. We report on two patients with antegrade flow in the ascending aorta despite aortic atresia. In one patient with hypoplastic left heart syndrome (aortic atresia, severe mitral stenosis), an intact interatrial septum/premature closure of the foramen ovale was found. While no other way of left atrial or ventricular decompression was found, echocardiography, angiography and the post-mortem examination showed left ventricular to coronary sinusoids as the sole pathway for systemic oxygenation. In a second patient with complex congenital heart disease, including aortic atresia, antegrade flow in the ascending aorta was through a left coronary fistula with shunt flow originating from the pulmonary trunk. This report describes systemic perfusion depending on retrograde coronary flow due to coronary-cameral (sinusoids) and coronary arterio-venous fistulas leading to the phenomenon of antegrade blood flow in the ascending aorta despite aortic atresia.

Aorta↗
PubMed2000

Endovascular stenting as an emergency treatment for neonatal coarctation.

We describe a neonate with critical coarctation of the aorta. Since treatment with Prostaglandin E1 had failed to reopen the arterial duct, and surgery was deemed to be associated with an unacceptably high risk in this unstable neonate, it was decided to perform balloon dilation of the coarctation as a palliative procedure to stabilize the patient. Balloon angioplasty failed to reduce the pressure gradient across the coarctation, so a stent was implanted retrogradely as an emergency procedure. Subsequently, the stented segment was resected surgically and end-to-end anastomosis created without complications at seven months of age.

Aortic Coarctation↗
PubMed2000

Is screw divergence in femoral bone-tendon-bone graft fixation avoidable in anterior cruciate ligament reconstruction using a single-incision technique? A radiographically controlled cadaver study.

Interference screw fixation of patellar tendon bone-tendon-bone grafts for anterior cruciate ligament reconstruction has proven to be a method with high pullout strength if screw divergence is avoided. Twenty-four fresh-frozen cadaveric human knees were used to identify the ideal position for a portal and an optimal knee flexion angle to obtain parallel placement of screw and bone block. On all specimens, anterior cruciate ligament reconstruction was performed using a single-incision technique. In the first part of this study, screw placement was analyzed in the frontal plane. In the second part, screw placement was investigated in the sagittal plane, measuring the additional flexion required between femoral tunnel drilling (at 60 degrees of knee flexion) and screw insertion to obtain parallel screw placement. For both part I and II, image intensification was used. In the third part, femoral screw placement was carried out through a paraligamentous approach and with additional flexion of 10 degrees, 20 degrees, 30 degrees, 40 degrees, 50 degrees, and 60 degrees. This study shows that screw placement with minimal divergence in the frontal and sagittal planes can be achieved by inserting the screw through a nearly central portal and flexing the knee an additional 35 degrees to 40 degrees.

Aged↗
PubMed2000

Chronic stretch of engineered heart tissue induces hypertrophy and functional improvement.

To examine the influence of chronic mechanical stretch on functional behavior of cardiac myocytes, we reconstituted embryonic chick or neonatal rat cardiac myocytes to a 3-dimensional engineered heart tissue (EHT) by mixing freshly isolated cells with neutralized collagen I and culturing them between two Velcro-coated silicone tubes, held at a fixed distance with a metal spacer. After 4 days, EHTs were subjected to a phasic unidirectional stretch for 6 days in serum-containing medium. Compared to unstretched controls, RNA/DNA and protein/cell ratios increased by 100% and 50%, respectively. ANF mRNA and alpha-sarcomeric actin increased by 98% and 40%, respectively. Morphologically, stretched EHTs exhibited improved organization of cardiac myocytes into parallel arrays of rod-shaped cells, increased cell length and width, longer myofilaments, and increased mitochondrial density. Thus, stretch induced phenotypic changes, generally referred to as hypertrophy. Concomitantly, force of contraction was two- to fourfold higher both under basal conditions and after stimulation with calcium or the beta-adrenergic agonist isoprenaline. Contraction kinetics were accelerated with a 14-44% decrease in twitch duration under all those conditions. In summary, we have developed a new in vitro model that allows morphological, molecular, and functional consequences of stretch to be studied under defined conditions. The main finding was that stretch of EHTs induced cardiac myocyte hypertrophy, which was accompanied by marked improvement of contractile function.

Adrenergic beta-Agonists↗
PubMed2000

Conventional ventilation versus high-frequency oscillation: hemodynamic effects in newborn babies.

OBJECTIVE: We conducted a prospective study to assess the hemodynamic effects of conventional mechanical ventilation (CMV) compared with high-frequency oscillation (HFO) in newborn babies with respiratory distress syndrome. METHODS: A total of 18 consecutive term and preterm infants were examined by two-dimensional M-mode and pulsed Doppler echocardiography. RESULTS: Five patients had to be excluded, three of them because of increasing cardiovascular support after initiation of HFO. The remaining 13 infants (seven males, six females) had a median gestational age of 33 wks (range, 25-40) and a birth weight of 2350 g (range, 790-3600). Patients entered the study at 21 hrs (range, 5-69) of life, receiving total maintenance fluid of 90 mL/kg/day (range, 60-120). Five babies (38%) needed continuous inotropic support. HFO was used as a rescue therapy in infants who failed with CMV. In all 13 patients, HFO significantly impaired cardiac performance compared with CMV by decreasing aortic velocity-time integral: median, 10.2 cm (range, 6.0-14.6) vs. 8.3 cm (range, 5.3-12.4; p<.002); stroke volume: median, 3.8 mL (range, 1.6-6.8) vs. 3.2 mL (range, 1.3-5.9; p<.002); and cardiac index: 281 mL/min/kg of body weight (range, 177-579) vs. 200 mL/min/kg of body weight (range, 156-591; p<.002). Fractional shortening was also significantly reduced: median, 0.31% (range, 0.24-0.44) vs. 0.29% (range, 0.20-0.34; p<.01), because of a significantly smaller left ventricular diastolic diameter during HFO: median, 1.4 cm (range, 1.0-1.9) vs. 1.4 cm (range, 0.9-1.8; p<.05), with a median difference of -0.07 cm (range, -0.4-0.2). HFO also causes a significant decrease in heart rate-corrected left ventricular ejection time: median, 0.25 sec (range, 0.23-0.28) vs. 0.23 sec (range, 0.21-0.26; p < .02) and heart rate-corrected velocity of circumferential fiber shortening (Vcfc): median, 1.3 circ/sec (range, 1.0-1.6) vs. 1.2 circ/sec (range, 0.9-1.4; p<.05). Left ventricular end-systolic wall stress (LVESWS; g/cm2) remained stable. The correlation between Vcfc and LVESWS did not show any significance (CMV, r2 = .2; HFO, r2 = .09). The regression line between Vcfc and LVESWS showed a higher y-intercept and steeper slope during CMV than during HFO. Heart rate, mean arterial pressure, and left ventricular systolic diameter remained unchanged. CONCLUSIONS: In newborn babies, HFO significantly decreased left ventricular cardiac output caused by reduced left ventricular filling and HFO decreased contractility at higher mean airway pressures than with CMV.

Cardiac Output↗
PubMed1999

Percutaneous transluminal angioplasty for the treatment of complete arterial occlusion after retrograde cardiac catheterization in infancy.

Nine patients with arterial thrombosis were treated with transcatheter recanalization and subsequent balloon dilation of the occluded vessel. Repeat angiography or duplex sonography 3 to 14 months after intervention showed completely patent arteries without restenosis in 7 patients; there was residual narrowing of the vessel in the remaining 2 patients.

Angiography↗
PubMed1999

Locked lateral patellar dislocation: a rare case of irreducible patellar dislocation requiring open reduction.

Irreducible patellar dislocations are rare injuries, but those that do occur are mainly directed intra-articularly. In this case, a 53-year-old woman sustained a locked lateral patellar dislocation when falling from a chair. A preoperative CT-scan revealed bony avulsions at the insertion of the vastus medialis muscle, the medical retinaculum, and partial disruption of the ligamentum patellae from the apex patellae. Open reduction was necessary and the torn structures were reattached with anchor systems and sutures. Postoperative management included intensive physiotherapy. At 1 year after surgery, the patient was without swelling or pain and had a normal gait, but flexion was restricted to 120 degrees. All postoperative radiographs showed the patella correctly placed in the femoral groove.

Accidental Falls↗
PubMed1999

A randomized trial comparing primary angioplasty with a strategy of short-acting thrombolysis and immediate planned rescue angioplasty in acute myocardial infarction: the PACT trial. PACT investigators. Plasminogen-activator Angioplasty Compatibility Trial.

OBJECTIVES: The study evaluated the efficacy and safety of a short-acting reduced-dose fibrinolytic regimen to promote early infarct-related artery (IRA) patency during the inherent delay experienced by infarct patients referred for angioplasty as the principal recanalization modality. BACKGROUND: Previous approaches using long-acting, full-dose thrombolytic infusions rarely showed benefit, but they did increase adverse event rates. METHODS: Following aspirin and heparin, 606 patients were randomized to a 50-mg bolus of recombinant tissue-type plasminogen activator (rt-PA) (alpha half-life 4.5 min) or to placebo followed by immediate angiography with angioplasty if needed. The end points included patency rates on catheterization laboratory (cath lab) arrival, technical results when PTCA (percutaneous transluminal coronary angioplasty) was performed, complication rates, and left ventricular (LV) function by treatment assignment and time to restored patency following angioplasty. RESULTS: Patency on cath lab arrival was 61% with rt-PA (28% Thrombolysis in Myocardial Infarction trial [TIMI]-2, 33% TIMI-3), and 34% with placebo (19% TIMI-2, 15% TIMI-3) (p = 0.001). Rescue and primary PTCA restored TIMI-3 in closed arteries equally (77%, 79%). No differences were observed in stroke or major bleeding. Left ventricular function was similar in both treatment groups, but convalescent ejection fraction (EF) was highest with a patent IRA (TIMI-3) on cath lab arrival (62.4%) or when produced by angioplasty within an hour of bolus (62.5%). However, in 88% of angioplasties, the delay exceeded 1 h: convalescent EF 57.3%. CONCLUSIONS: Tailored thrombolytic regimens compatible with subsequent interventions lead to more frequent early recanalization (before cath arrival), which facilitates greater LV function preservation with no augmentation of adverse events.

Aged↗
PubMed1999

Differential profile of facial injuries among mountainbikers compared with bicyclists.

BACKGROUND: Bicyclists and mountainbikers are prone to facial trauma. In the current study, we present a large series of cycling-related sports trauma to the face in an effort to identify the injury pattern among mountainbikers compared with bicyclists. METHODS: The medical records of a single pediatric and adult Level I trauma center were evaluated from January 1, 1991, through October 31, 1996. All admissions with injuries caused by cycling-related sports were reviewed, analyzed, and compared according to age and sex distributions, causes of accidents, injury types, frequency, and localization of fractures and associated injuries. The injury types were divided into three categories: fractures, dentoalveolar trauma, and soft-tissue injuries. RESULTS: Five hundred sixty-two injured bicyclists (10.3% of all trauma patients) were registered at the Department of Oral and Maxillofacial Surgery, University of Innsbruck, Austria, during the study period, accounting for 31% of all sports-related or 48.4% of all traffic collisions, respectively. The review of the patient records revealed especially more severe injury profiles in 60 mountainbikers, with 55% facial bone fractures, 22% dentoalveolar trauma, and 23% soft-tissue injuries, compared with 502 street cyclists showing 50.8% dentoalveolar trauma, 34.5% facial bone fractures, and 14% soft-tissue lesions. The dominant fracture site in bicyclists was the zygoma (30.8%), whereas mountainbikers sustained an impressive 15.2% Le Fort I, II, and III fractures. Condyle fractures were more common in bicyclists, with 18.8% opposing 10.8% in mountainbikers. CONCLUSION: Appropriate design of helmets with faceguards will reduce the incidence of facial injuries caused by cycling-related accidents and incentives are needed for making helmet use compulsory for all cyclists, particularly for mountainbikers.

Adolescent↗
PubMed1998

Transcatheter recanalization and subsequent stent implantation for the treatment of early postoperative thrombosis of modified Blalock-Taussig shunts in two children.

Two babies with duct-dependent cyanotic congenital heart disease were palliated with modified Blalock-Taussig shunts. One patient was diagnosed to have tetralogy of Fallot, and the other patient, tricuspid atresia type Ia. Early postoperative arterial oxygen saturations dropped significantly due to shunt thrombosis. Both patients were successfully treated with angioplasty and stent implantation.

Angioplasty, Balloon, Coronary↗
PubMed1998

[Acute compartment syndrome of the lower leg after ankle joint sprain. A case report].

In the field of traumatology, compartment syndromes of the lower extremity are often seen after fractures and direct injuries, or after ischaemia. Other causes include over-exertion and non-traumatic causes such as acute rhabdomyolysis, drug-induced myositis and eosinophilic myositis. This paper describes the clinical and MR course of a compartment syndrome following an ankle sprain.

Acute Disease↗
PubMed1998

[Interventional therapy for hemangioendothelioma of the liver in a newborn infant using a central venous approach].

We report on a newborn (birth weight 3600 g) with high-output cardiac failure due to a large hepatic hemangioendothelioma requiring mechanical ventilation. One day post-partum therapy with steroids, furosemide, and digitalis was initiated. Despite this, the clinical condition deteriorated. Therefore, selective coil-embolization of the arterial vessels supplying the hemangioendothelioma was performed using a venous approach with passage to the arterial side via the ductus arteriosus. After the embolization the patient improved quickly and he was extubated 4 days postinterventionally. Follow-up sonography 4 months postinterventionally showed dramatic regression of the hepatic tumor. We conclude that the coil-occlusion of hepatic hemangioendothelioma should be performed early in symptomatic newborns as arterial puncture and its associated complications can be avoided by using a venous approach with passage to the arterial side via the ductus arteriosus. In addition, in this age group, access to the portal system can be gained through the umbilical vein to occlude portal venous supplies to the hepatic hemangioendothelioma.

Catheterization, Central Venous↗
PubMed1998

Intracellular fluorescent probe concentrations by confocal microscopy.

A general method is described that takes advantage of the optical sectioning properties of a confocal microscope to enable measurement of both absolute and relative concentrations of fluorescent molecules inside cells. For compartments within cells that are substantially larger than the point spread function, the fluorescence intensity is simply proportional to the concentration of the fluorophore. For small compartments, the fluorescence intensity is diluted by contributions from regions outside the compartment. Corrections for this dilution can be estimated via calibrations that are based on the intensity distribution found in a computationally synthesized model for a cell or organelle that has been blurred by convolution with the microscope point spread function. The method is illustrated with four test cases: estimation of intracellular concentration of a fluorescent calcium indicator; estimation of the relative distribution between the neurite and soma of a neuronal cell of the InsP3 receptor on the endoplasmic reticulum; estimation of the distribution of the bradykinin receptor along the surface of a neuronal cell; and relative distribution of a potentiometric dye between the mitochondria and cytosol as a means of assaying mitochondrial membrane potential.

3T3 Cells↗
PubMed1998

Transcatheter closure of atrial septal defects within the oval fossa: medium-term results in children using the 'ASDOS'-technique.

OBJECTIVES: The purpose of this study was to evaluate the safety and efficacy of the ASDOS-technique (Sulzer-Osypka GmbH, Germany) for transcatheter closure of atrial septal defects within the oval fossa. BACKGROUND: Although several attempts have been made to occlude defects within the oval fossa by transcatheter techniques, none of these has gained general acceptance. METHODS: Patients with a defect in the oval fossa measuring equal to or less than 20 mm diameter, with a residual septal rim of 5 mm or greater, body weight greater than 10 kg, with clinical indications for surgical closure were considered for transcatheter closure. Follow-up investigations were performed at discharge, after 1, 3, 6 and 9 months, as well as after 1 and 2 years. RESULTS: Of 78 patients considered for closure, a device was inserted in 41 patients (53%), with success being achieved in 40 patients (98%). The ages ranged from 1.1 to 15 years (7.8 +/- 1.92 years), the 'stretched' diameter of the defect from 10 to 20 mm (14.7 +/- 2.60 mm), and the diameters of the inserted devices from 25 to 45 mm (33.2 +/- 5.43 mm). Transient impairment of atrioventricular conduction occured in 4 patients. During the follow-up of 23.0 +/- 5.6 months elective surgical closure of a residual shunt was performed 26 months after insertion of the device in one patient. None of the other patients required surgery, hospitalisation or medical treatment, and none is requiring further treatment of the defect within the oval fossa. Fracture of one arm of the device occurred in 4 patients, but the fractured arms are in an unchanged and stable position after a period of at least 19 months. CONCLUSIONS: Our medium-term data show that transcatheter closure in children of defects within the oval fossa can be performed with a high efficacy and safety using the ASDOS-device.

Adolescent↗
PubMed1997

Changes in left ventricular function in shocked newborns.

OBJECTIVE: To assess whether the change in cardiac output after volume replacement is due to elevation of stroke volume or heart rate and to determine the effect of mechanical ventilation on the hemodynamic situation. DESIGN: Prospective study. SETTING: A ten-bed neonatal intensive care unit (level III) at a university hospital. PATIENTS: 15 consecutive newborns with blood pressure below the 10th percentile related to age and weight. INTERVENTIONS: Volume replacement with Ringer's lactate 20 ml/kg body weight. MEASUREMENTS AND RESULTS: Before and after volume replacement, arterial pressure recordings, blood gas analysis, and an echocardiographic study were carried out. Left ventricular and aortic diameters were measured by the two-dimensional M-mode technique and velocity time integral of aortic flow by the pulsed color Doppler technique. From these data, stroke volume and cardiac output were calculated. Cardiac output (703 +/- 204 vs 826 +/- 166 ml/ min, p < 0.005) and cardiac index (267 +/- 69 vs 302 +/- 55 ml/min per kg body weight, p < 0.01) changed significantly due to an appreciable elevation in stroke volume (5.2 +/- 1.7 vs 5.8 +/- 1.7 ml, p < 0.05), whereas heart rate was unaltered (140 +/- 12 vs 142 +/- 20 beats/min; NS). The change in blood pressure (32 +/- 5 vs 38 +/- 8 mm Hg, p < 0.01) was also significant. Cardiac index before and after volume replacement showed a significant inverse correlation with the severity of respiratory disease expressed as alveolar-arterial oxygen difference (A-aDO2) (A-aDO2 vs cardiac index before volume replacement: r = -0.77, p < 0.001; after volume replacement: r = -0.73, p < 0.005) or oxygenation index (oxygenation index vs cardiac index before volume replacement: r = -0.73, p < 0.005; after volume replacement: r = -0.73, p < 0.005). Changes in left ventricular diastolic diameter, left ventricular systolic diameter, and fractional shortening were not significant. CONCLUSIONS: These results indicate that the major regulator of left ventricular output in newborns with hypovolemic or cardiogenic shock is stroke volume and not heart rate and that cardiac output depends on the severity of the respiratory disease.

Cardiac Output↗
PubMed1997

Three-dimensional reconstitution of embryonic cardiomyocytes in a collagen matrix: a new heart muscle model system.

A method has been developed for culturing cardiac myocytes in a collagen matrix to produce a coherently contracting 3-dimensional model heart tissue that allows direct measurement of isometric contractile force. Embryonic chick cardiomyocytes were mixed with collagen solution and allowed to gel between two Velcro-coated glass tubes. During culture, the cardiomyocytes formed spontaneously beating cardiac myocyte-populated matrices (CMPMs) anchored at opposite ends to the Velcro-covered tubes through which they could be attached to a force measuring system. Immunohistochemistry and electron microscopy revealed a highly organized tissue-like structure of alpha-actin and alpha-tropomyosin-positive cardiac myocytes exhibiting typical cross-striation, sarcomeric myofilaments, intercalated discs, desmosomes, and tight junctions. Force measurements of paced or unpaced CMPMs were performed in organ baths after 6-11 days of cultivation and were stable for up to 24 h. Force increased with frequency between 0.8 and 2.0 Hz (positive "staircase"), increasing rest length (Starling mechanism), and increasing extracellular calcium. The utility of this system as a test bed for genetic manipulation was demonstrated by infecting the CMPMs with a recombinant beta-galactosidase-carrying adenovirus. Transduction efficiency increased from about 5% (MOI 0.1) to about 50% (MOI 100). CMPMs display more physiological characteristics of intact heart tissue than monolayer cultures. This approach, simpler and faster than generation of transgenic animals, should allow functional consequences of genetic or pharmacological manipulation of cardiomyocytes in vitro to be studied under highly controlled conditions.

Actins↗
PubMed1996

[Perilunate dislocation and dislocation fractures--results of surgical management].

We report 22 patients who sustained a perilunate dislocation (PD) with or without a fracture of the scaphoid. The carpal ligaments were explored and reattached in all cases. The fractured scaphoid in perilunate fracture dislocations (PFD) was stabilised by a Herbert screw in 13 cases and in one case with a Matti-Russe bone graft. After an average of 5 years the clinical score of Green and O'Brien showed good results for both PD and PFD. Patients with PFD had less pain and better grip than the patients with PD. The sagittal range of motion (average between 70 degrees and 99 degrees) and the subjective limitation in sports and work were equal for PD and PFD. The only open injury (PD) had the worst clinical result. All patients with PD showed a carpal instability dissociative of the proximal row (CID) and an arthrosis of the radiocarpal joint. In the patients with PFD a CID could be seen in 78% and an arthrosis in 93%. A carpal collapse occurred in 75% of cases after PD and in 29% after PFD. In 57% of cases the PFD was accompanied by a disruption of the SL ligament. The anatomical reconstruction of the scaphoid is essential for good carpal alignment. The stable fixation of bony avulsions showed good results. A CID could not be avoided in any of our patients with PD.

Adolescent↗