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Biomedical subjects

J Hess

Publications and source records attributed to J Hess.

At least 37 records · Page 2Linked to original sources
PubMed2003

Myocardial perfusion and coronary flow reserve assessed by positron emission tomography in patients after Fontan-like operations.

Ventricular dysfunction in patients after Fontan-like operations (FLOs) is a serious complication that might contribute to poor long-term results. Ischemic heart disease will have debilitating consequences on a Fontan heart. Ten patients (15.8 +/- 5.01 years) after FLO had transesophageal echocardiography and cardiac catheterization 9.3 +/- 4.2 years after surgery. Myocardial perfusion was assessed by NH3-positron emission tomography (rest/adenosine) and compared with that of 10 healthy adults (26.1 +/- 6.3 years). Ventricular function was normal in 4 and reduced in 6 patients; end systolic and end diastolic meridional wall stress was significantly elevated in the FLO group. Coronary angiography revealed no stenosis of the coronaries. Compared to normals, myocardial blood flow (MBF) at rest was higher in the FLO group (0.99 +/- 0.25 vs 0.77 +/- 0.17 ml/g/min, p <0.05), whereas MBF after vasodilatation (2.12 +/- 0.78 vs 3.10 +/- 0.85 ml/g/min, p <0.05) and coronary flow reserve (CFR) was reduced (2.5 +/- 0.88 vs 4.1 +/- 1.01, p <0.05), especially in those with impaired ventricular function. Coronary vascular resistance after vasodilatation was elevated in the FLO group (38.2 +/- 17.4 vs 24.5 +/- 8.3 mmHg/ml/g/min, p <0.05). Altered MBF, increased meridional wall stress, and impaired CFR are common findings in FLO. Attenuated CFR and reduced ventricular function are significantly correlated and may be risk factors for the long-term outcome.

Adolescent↗
PubMed2003

Pregnancy in congenital cardiac disease: an increasing challenge for cardiologists and obstetricians -- a prospective multicenter study.

OBJECTIVES: Aim of this study was to assess the occurrence of pregnancy-related complications of mother and child during pregnancy, delivery and puerperium in women with CCD prospectively. STUDY DESIGN, POPULATION: This prospective multicenter study included 122 pregnancies in 106 women with CCD (72 with, 34 without previous cardiac surgery). Patient age was 17-44, median 26 years. Cardiac and non-cardiac complications, mode of delivery, abortion, and CCD of the newborn were assessed. RESULTS: Initially all women were in Functional Class I or II. Worsening during pregnancy occurred in 25.5% (n=27), mainly during the second and third trimester. Significant problems due to bleeding, hypertension, rhythm disturbances, endocarditis, liver congestion, increasing cyanosis or death, occurred in 11.3%. Twelve per cent of deliveries were premature. Five women had therapeutic abortion, nine spontaneous abortions, nine preterm births, and one intrauterine death. Seventy-nine per cent (n=85) delivered spontaneously; 21.3% (n=23) had caesarean section. Of the 111 live born children, 5.4% (n=6) had a CCD. CONCLUSIONS: Most women with CCD and a good functional class before pregnancy tolerate pregnancy without major problems. However, pregnancy may induce serious cardiac and obstetric complications. The specific risks require an individualized multidisciplinary patient-management by experienced physicians.

Adolescent↗
PubMed2003

Treatment of Candida albicans endocarditis: case report and a review.

Candida albicans endocarditis occurs mostly in patients with congenital heart disease; open heart surgery is the greatest predisposing factor. We report on a child with truncus arteriosus communis and a large Candida vegetation within the prosthetic pulmonary valve, causing severe right ventricular outflow tract obstruction. Treatment was performed successfully by surgery and administration of liposomal amphotericin B (AmBisome) and 5-flucytosine.

Amphotericin B↗
PubMed2003

Impaired myocardial blood flow and coronary flow reserve of the anatomical right systemic ventricle in patients with congenitally corrected transposition of the great arteries.

OBJECTIVES: To investigate myocardial blood flow of the morphological right systemic ventricle in unoperated patients with congenitally corrected transposition of the great arteries (CCTGA) by positron emission tomography (PET). DESIGN: Prospective cross sectional clinical study. SETTING: Tertiary referral centre for paediatric cardiology. PATIENTS: 15 patients with CCTGA were investigated by PET with nitrogen-13 ammonia at rest and during adenosine vasodilatation. A subgroup of seven patients had isolated CCTGA (group A, mean (SD) age 30.3 (11.9) years) and the remaining eight patients had complex CCTGA associated with subpulmonary stenosis; four of this second group also had ventricular septal defect (group B, mean (SD) age 30.6 (16.4) years). Eleven healthy adults (mean (SD) age 26.2 (5.1) years) served as the control group. RESULTS: Resting myocardial blood flow was not different between both groups of patients with CCTGA and the controls. Hyperaemic blood flows were significantly lower in both groups of CCTGA than in the control group (mean (SD) 195 (21) ml/100g/min in group A, 201 (27) ml/100g/min in group B, 309 (74) ml/100g/min in the control group; p < 0.001). Thus, coronary flow reserve was significantly lower in both groups of CCTGA than in the control group (mean (SD) 2.5 (0.28) in group A, 2.6 (0.48) in group B, and 4.0 (0.73) in the control group; p < 0.001). CONCLUSION: Blood flow measurements suggest that coronary reserve is decreased in the absence of ischaemic symptoms in patients with CCTGA. The global impairment of stress flow dynamics may indicate altered global vasoreactivity, and quantitative changes in microcirculation suggest that their role in the pathogenesis of systemic right ventricular dysfunction is important.

Adenosine↗
PubMed2002

Coil embolization therapy in congenital coronary arterial fistulas.

Three pediatric patients (8.5 years, 3 years, and 1 month) presented with congenital coronary arterial fistulas. In all cases the fistulas entered into the right side of the heart (main pulmonary artery, n = 1; right ventricle, n = 2). In the first patient, the fistula and an open ductus arteriosus were closed during the same intervention. The second patient presented with a single left coronary ostium and residual shunt from the coronary artery system to the right ventricle after surgery. The third child had pulmonary atresia with intact ventricular septum and a fistula from the left coronary artery to the right ventricle. The fistulas in all patients were managed with coil occlusion. Fistula occlusion was documented with angiocardiography.

Arterio-Arterial Fistula↗
PubMed2002

Cardiac output determination in children: equivalence of the transpulmonary thermodilution method to the direct Fick principle.

OBJECTIVE: To show the equivalence of the transpulmonary thermodilution method to the direct Fick principle in children. DESIGN: Prospective single-centre study. SETTING: A 16-bed paediatric cardiac ICU and a cardiac catheterisation laboratory at an university affiliated centre for paediatric cardiology and congenital heart disease. PATIENTS: We consecutively investigated 18 patients (mean age 12.1 +/- 6.4 years) during cardiac catheterisation and after corrective cardiac operation. METHODS AND RESULTS: We prospectively defined limits of equivalence for cardiac index (CI) for both methods of +/- 0.25 l/min x m(2). We measured oxygen consumption for determination of CI by Fick as the clinical "gold standard" and performed a set of three transpulmonary thermodilution measurements. The mean CI(Fick) was 2.88 +/- 1.07 l/min x m(2) (range 1.10-4.62 l/min x m(2)) and CI(TPID)was 2.85 +/- 1.03 l/min x m(2)(range 1.02-4.49 l/min x m(2)). The mean difference between CI(Fick) and CI(TPID)was 0.030 +/- 0.168 l/min x m(2), and limits of agreement -0.306 to 0.366 l/min x m(2)(90% confidence interval -0.040 to 0.099 l/min x m(2)). The regression equation was : CI(Fick)=1.0244 x CI(TPID)-0.040, r(2) = 0.976, P < 0.0001. The intraclass coefficient of reliability for three repeated measurements of CI(TPID) was 0.97, the corresponding lower limit of the 95% confidence interval was 0.94. CONCLUSION: We demonstrated the equivalence of CI measurement by transpulmonary thermodilution and the Fick principle in children. This new method may improve hemodynamic monitoring and management in seriously ill children.

Adolescent↗
PubMed2002

Cardiac surgery with deep hypothermic circulatory arrest produces less systemic inflammatory response than low-flow cardiopulmonary bypass in newborns.

OBJECTIVE: We sought to compare low-flow cardiopulmonary bypass with deep hypothermic circulatory arrest in respect to the influence on the systemic inflammatory response. METHODS: Twenty-three infants weighing less than 10 kg and scheduled for repair of congenital malformations were enrolled in a randomized, controlled study. Eleven patients underwent cardiac surgery with deep hypothermic circulatory arrest (the DHCA group). Low-flow cardiopulmonary bypass was used in another 12 patients (the LF group). Interleukin 6 and 8 and anaphylatoxin C3a levels were measured 6 times perioperatively. Also, perioperative weight gain and a radiologic soft-tissue index were compared. RESULTS: All patients had an uneventful clinical course. Duration of deep hypothermic circulatory arrest was 40 +/- 4 minutes; the bypass time was significantly shorter in the DHCA group (85 +/- 8 vs 130 +/- 19 minutes). However, the duration of the operation was similar in both groups (245 +/- 30 vs 246 +/- 30 minutes). During cardiopulmonary bypass (rewarming), the concentration of C3a (3751 +/- 388 vs 5761 +/- 1688 ng/mL, mean +/- SEM) was significantly lower in the DHCA group than in the LF group. The interleukin 8 level was significantly lower, and the interleukin 6 level had a tendency to be lower in the DHCA group compared with levels in the LF group. There was less weight gain on the first postoperative day in the DHCA group (65 +/- 61 vs 408 +/- 118 g). The soft-tissue index suggested reduced edema formation in the DHCA group. CONCLUSION: Deep hypothermic circulatory arrest produces less systemic inflammatory response than low-flow cardiopulmonary bypass. In addition, there is an indication of less fluid accumulation postoperatively.

Blood Pressure↗
PubMed2001

Polysubstance abuse-vulnerability genes: genome scans for association, using 1,004 subjects and 1,494 single-nucleotide polymorphisms.

Strong genetic contributions to drug abuse vulnerability are well documented, but few chromosomal locations for human drug-abuse vulnerability alleles have been confirmed. We now identify chromosomal markers whose alleles distinguish drug abusers from control individuals in each of two samples, on the basis of pooled-sample microarray and association analyses. Reproducibly positive chromosomal regions defined by these markers in conjunction with previous results were especially unlikely to have been identified by chance. Positive markers identify the alcohol dehydrogenase (ADH) locus, flank the brain-derived neurotropic factor (BDNF) locus, and mark seven other regions previously linked to vulnerability to nicotine or alcohol abuse. These data support polygenic contributions of common allelic variants to polysubstance abuse vulnerability.

Adult↗
PubMed2001

Protective efficacy against tuberculosis of ESAT-6 secreted by a live Salmonella typhimurium vaccine carrier strain and expressed by naked DNA.

We have constructed a recombinant (r) attenuated Salmonella typhimurium strain which secretes ESAT-6 of Mycobacterium tuberculosis via the hemolysin secretion system of E. coli. Additionally, we have ligated ESAT-6 to different commercially available mammalian expression systems for use as naked DNA vaccines. We studied protection against M. tuberculosis induced by vaccination with each of these constructs alone or in combination in mice. Vaccination with a single dose of r S. typhimurium secreting ESAT-6 reduced numbers of tubercle bacilli in the lungs throughout the course of infection. The combined prime-boost vaccination did not considerably enhance protection.

Animals↗
PubMed2001

Contribution of MHC class I-dependent immune mechanisms induced by attenuated recombinant Salmonella typhimurium secreting superoxide dismutase to protection against murine listeriosis.

A recombinant (r)Salmonella typhimurium aroA strain secreting the naturally non-secreted superoxide dismutase (SOD) of Listeria monocytogenes controls murine listeriosis dependent on 'transporter associated with antigen processing' (TAP)-mediated immune mechanisms. TAP1-deficient mice (devoid of most CD8 T cells) vaccinated with this rSalmonella SODs strain succumbed to lethal L. monocytogenes challenge, whereas C57BL/6 mice were protected by this vaccine. Moreover, vaccination of H-2I-Abeta-deficient mice (lacking major histocompatibility class (MHC) II molecules and thus devoid of mature CD4 TCR-alphabeta cells), of TAP1-deficient as well as of beta2microglobulin-deficient mice (devoid of conventional CD8 T cells) with a sublethal dose of L. monocytogenes and subsequent challenge with rSalmonella control or SODs strain revealed contribution of both MHC class I- and MHC class II-dependent immune mechanisms to the control of secondary Salmonella infection. Finally, the clearance of rSalmonella SODs bacteria was achieved in TAP1-deficient animals vaccinated with L. monocytogenes. Our data suggest a role of TAP-dependent mechanisms in priming of protective immunity by rSalmonella micro-organisms secreting SOD.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

The effect of overhead drilling position on shoulder moment and electromyography.

The effect of overhead drilling tasks on electromyographic (EMG) activity and shoulder joint moment was examined in this study. Twenty subjects simulated an overhead drilling task using a close, middle and far reach position while standing on either a lower or a higher step of a stepladder. Root mean square amplitude (AMP) of EMG activity from the dominant side anterior deltoid, biceps brachii and triceps brachii muscles was used to determine muscular load. Digital video was used to determine shoulder joint moment using 2-dimensional static link segment modelling in the sagittal plane. The results demonstrated that, compared to the far reach position, using the close reach position significantly decreased anterior deltoid AMP and biceps brachii AMP and moment, but increased triceps brachii AMP. Compared to the lower step, using the higher step significantly decreased anterior deltoid AMP and triceps AMP and moment, while increasing biceps AMP in the close position. There was no significant change noted in EMG median frequency indicating that fatigue was minimized. Moment increased monotonically with AMP. The findings indicated that workers performing overhead tasks should work close to their body in order to minimize shoulder forces. The implications of this recommendation are discussed.

Adult↗
PubMed2001

Myocardial blood flow and flow reserve after coronary reimplantation in patients after arterial switch and ross operation.

BACKGROUND: Coronary reimplantation is used in therapy for congenital heart disease, such as in the arterial switch (ASO) and Ross operations. The adequacy of myocardial perfusion may remain a matter of concern. The aim of the present study was to stratify the effect of coronary reimplantation on myocardial perfusion and to highlight the clinical relevance of any attenuation in myocardial perfusion. METHODS AND RESULTS: A total of 21 children with transposition of the great arteries at a mean interval of 11.2+/-2.9 years after ASO and 9 adolescents at a mean interval of 4.2+/-2.1 years after the Ross procedure were investigated. All patients were asymptomatic and had a normal exercise capacity. On stress echocardiography, 2 of the ASO patients had dyskinetic areas within the left ventricular myocardium, and 5 had adenosine-induced perfusion defects on positron emission tomography. No coronary obstruction was detected on coronary angiography in any patient, but a common finding was right coronary dominance and a small caliber of the distal part of the left anterior descending artery. Coronary flow reserve (CFR) was significantly reduced in all patients after ASO when compared with 10 normal healthy volunteers (age, 25.6+/-5.3 years). CFR was normal in the 9 patients who had the Ross operation (age, 19.2+/-7.6 years); exercise-induced perfusion defects were not detected in the Ross patients. CONCLUSIONS: Children after ASO are asymptomatic, without clinical signs of coronary dysfunction. In contrast to patients who had the Ross operation, stress-induced perfusion defects and an attenuated CFR were documented. The prognostic implications of these findings and the clinical consequences are unclear; nevertheless, close clinical follow-up of ASO patients is mandatory.

Adolescent↗
PubMed2001

AP-1 and Cbfa/runt physically interact and regulate parathyroid hormone-dependent MMP13 expression in osteoblasts through a new osteoblast-specific element 2/AP-1 composite element.

The expression of MMP13 (collagenase-3), a member of the matrix metalloproteinase family, is increased in vivo as well as in cultured osteosarcoma cell lines by parathyroid hormone (PTH), a major regulator of calcium homeostasis. Binding sites for AP-1 and Cbfa/Runt transcription factors in close proximity have been identified as cis-acting elements in the murine and rat mmp13 promoter required for PTH-induced expression. The cooperative function of these factors in response to PTH in osteoblastic cells suggests a direct interaction between AP-1 and Cbfa/Runt transcription factors. Here, we demonstrate interaction between c-Jun and c-Fos with Cbfa/Runt proteins. This interaction depends on the leucine zipper of c-Jun or c-Fos and the Runt domain of Cbfa/Runt proteins, respectively. Moreover, c-Fos interacts with the C-terminal part of Cbfa1 and Cbfa2, sharing a conserved transcriptional repression domain. In addition to the distal osteoblast-specific element 2 (OSE2) element in the murine and rat mmp13 promoter, we identified a new proximal OSE2 site overlapping with the TRE motif. Both interaction of Cbfa/Runt proteins with AP-1 and the presence of a functional proximal OSE2 site are required for enhanced transcriptional activity of the mmp13 promoter in transient transfected fibroblasts and in PTH-treated osteosarcoma cells.

Animals↗
PubMed2001

Recombinant attenuated bacteria for the delivery of subunit vaccines.

Using attenuated intracellular bacteria as carriers, we have developed two different approaches for the delivery of subunit vaccines encoding heterologous antigens. The first system is based on the direct secretion of the heterologous antigens in Gram-negative bacteria via the hemolysin secretion system of Escherichia coli into either phagosome or cytosol of infected cells. The second approach is based on the transport of eukaryotic antigen expression vectors by intracellular bacteria like Listeria and Salmonella into the host cell and here, preferably, into the cytosolic compartment. After release of the plasmid DNA from the bacteria, the plasmid-encoded antigens can be expressed directly by the host cell. Finally, we combined both types of subunit vaccines in one live vector - we equipped Salmonella strains with a phagosomal escape function by utilization of the hemolysin secretion system and used this recombinant vaccine strain for the delivery of a eukaryotic antigen expression vector into the cytosol of macrophages.

Animals↗
PubMed2001

Induction of pre-B cell proliferation after de novo synthesis of the pre-B cell receptor.

The assembly of a pre-B cell receptor (pre-BCR) composed of an Ig mu heavy chain (mu H-chain), the surrogate light (SL) chain, and the Ig alpha/beta dimer is critical for late pro-B cells to advance to the pre-B cell stage. By using a transgenic mouse model, in which mu H-chain synthesis is solely driven by a tetracycline-controlled transactivator, we show that de novo synthesis of mu H-chain in transgenic pro-B cells not only induces differentiation but also proliferation. This positive effect of mu H-chain synthesis on proliferation requires the presence of SL chain and costimulatory signals provided by stromal cells or IL-7. We conclude that pre-BCR signaling induces clonal expansion of early pre-B cells.

Animals↗
PubMed2001

From evil to good: a cytolysin in vaccine development.

Current vaccination strategies mainly target antigens into the phagosomal, major histocompatibility complex class II antigen-processing pathway and thus lead predominantly to humoral immune responses. The elicitation of cytotoxic T-cell responses instead requires introduction of antigens into the cytosol of professional antigen-presenting cells (APCs). The intracellular bacterium Listeria monocytogenes gains access to the host cell cytosol by means of a cytolysin, listeriolysin O. Vaccine researchers have successfully employed listeriolysin in novel vaccination approaches to provide access to the cytosol of professional APCs for purified protein antigens, attenuated bacterial vaccine strains, DNA vaccines and liposome contents.

Animals↗