Biomedical subjects

W Koch

Publications and source records attributed to W Koch.

At least 55 records · Page 3Linked to original sources

PubMed2000

G protein beta3 subunit polymorphism and risk of thrombosis and restenosis following coronary stent placement.

C825T polymorphism in the G protein beta3 subunit gene (GNB3) has been associated with arterial hypertension, coronary artery disease and myocardial infarction. On the cellular level, C825T polymorphism is associated with altered transmembrane signaling via adenylyl cyclase inhibiting (G(i)) G proteins. This study was designed to test whether C825T polymorphism has an impact on the processes leading to restenosis and thrombosis following coronary stenting. The primary endpoint of the study was angiographic restenosis (> or =50% diameter stenosis) at 6-month follow-up. Secondary endpoint was angiographically proven stent thrombosis within 30 days of implantation. In the 562 consecutive patients C825T genotype was CC, 46.1%, CT, 45.2% and TT, 8.7%. The incidence of angiographic restenosis was 32.7% in homozygous carriers of the C allele, 28.2% in CT patients and 33.3% in homozygous carriers of the T allele (P = 0.563). C825T genotype distribution in 34 consecutive patients with subacute stent thrombosis (44.0% CC, 50.0% CT, and 6.0% TT) was not different from that of 451 patients with angiographically patent stented vessel (45.4% CC, 44.6% CT, 10.0% TT; P = 0.644). In conclusion, C825T polymorphism has no appreciable impact on the mechanisms leading to thrombosis and restenosis following coronary stent placement.

Aged↗

PubMed2000

Role of climate, crown position, tree age and altitude in calculated ozone flux into needles of Picea abies and Pinus cembra: a synthesis.

Ozone (O(3)) flux into Norway spruce (Picea abies) and cembran pine (Pinus cembra) needles was estimated under ambient conditions at six rural sites between 580 and 1950 m a.s.l. We also assessed age-related differences in O(3) flux by examining changes in leaf conductance across the life span of Norway spruce. At the leaf level O(3) flux into the needles was effectively controlled by stomatal conductance and, hence by factors such as temperature, irradiance and humidity, which control stomatal conductance. Seasonal variations in O(3) flux were mainly attributed to the course of the prevailing temperature. During the growing season, however, data have emphasised leaf-air vapour pressure difference as the environmental factor most likely to control stomatal conductance and O(3) flux into the needles. In the sun crown stomatal conductance averaged over the growing season decreased with increasing tree age from 42.0+/-3.5 mmol O(3) m(-2) s(-1) in 17-year-old trees to 7.1+/-1.0 mmol O(3) m(-2) s(-1) in 216-year-old trees, indicating that O(3) concentration in the substomatal cavities is higher in young than in old trees. Independent from tree age stomatal conductance and O(3) flux were approximately 50% lower in shade needles as compared to sun-exposed needles. Stomatal conductance was also greater in the current flush (24+/-5.6 mmol O(3) m(-2) s(-1)) and in 1-year old needles (16+/-4 mmol O(3) m(-2) s(-1)) than in older needle age classes (12+/-1 mmol O(3) m(-2) s(-1), averaged across the four older needle age classes). In trees similar in age (60-65 years old) average O(3) flux into sun needles increased from 0.55+/-0.36 nmol m(-2) s(-1) at the valley floor to 0.9 nmol m(-2) s(-1) in 1950 m a.s.l. Cumulative O(3) uptake during the vegetation period increased from 11.4+/-1.7 mol m(-2) in the valley to 14 mol m(-2) at the alpine timberline. Although stomatal conductance provides the principal limiting factor for O(3) flux, additional field research is necessary in order to improve our understanding concerning the quantitative 'physiological threshold dose' which internally can be active and can have adverse effects of O(3) on forest trees.

Journal Article↗

PubMed2000

PlA polymorphism of glycoprotein IIIa and risk of adverse events after coronary stent placement.

OBJECTIVE: We designed this prospective study to test the hypothesis that platelet antigen (PlA) polymorphism of glycoprotein (GP) IIIa is associated with an increased risk for adverse events after coronary stent placement. BACKGROUND: Platelets play a central role in arterial thrombosis. The PlA polymorphism of GP IIIa, a constituent of the fibrinogen receptor, may influence the platelet function and, thereby, the early outcome of patients after coronary stent placement. METHODS: The study included 1,759 consecutive patients with stable or unstable angina and successful coronary stent placement. Platelet antigen genotypes were determined by allele-specific restriction enzyme analysis. The end point of the study was a composite of death, myocardial infarction and urgent revascularization during the first 30 days after stent placement. RESULTS: The PlA1 genotype of the patients included was: 70.2% were homozygous for platelet antigen 1 (PlA1), 2.6% homozygous for platelet antigen 2 (PlA1), and 27.2% were heterozygous (PlA1/A2). The incidence of the composite end point was 5.5% among PlA2 carriers and 5.4% in homozygous PlA1 subjects (p = 0.94). It was 5.4% in PlA1/A1 patients, 4.8% in PlA1/A2 patients and 13.0% in PlA2A2 patients (p = 0.06). The combined incidence of death or myocardial infarction was 4.3% in PlA1/A1 patients, 4.2% in PlA1/A2 patients and 13.0% in PlA2/A2 patients (p = 0.02). CONCLUSIONS: The isolated presence of the PlA2 allele in heterozygous patients is not associated with any detectable increase in the risk for an adverse 30-day outcome after coronary stenting. This study suggests also that an increased risk is likely to be present in homozygous carriers of the PlA2 allele, but this should be confirmed in a much larger series of patients.

Aged↗

PubMed2000

Protective role against restenosis from an interleukin-1 receptor antagonist gene polymorphism in patients treated with coronary stenting.

OBJECTIVES: To test the hypothesis that interleukin-1 receptor antagonist (IL-1ra) gene polymorphism contributes to the risk of restenosis after coronary stenting. BACKGROUND: Cytokines of the interleukin-1 (IL-1) family play a central role in regulating inflammatory responses. There is strong evidence to support IL-1 involvement in smooth muscle cell mitogenesis and extracellular matrix metabolism. The IL-1ra counters the proinflammatory effects of IL-1. The interleukin-1 receptor antagonist gene (IL-1RN) contains several well-characterized polymorphic sites that correlate with altered IL-lra levels. METHODS: In 1,850 consecutive patients, clinical and angiographic measures ofrestenosis were evaluated over one year after coronary stent placement. Repeat angiography at six months was achieved in 84% of the patients; angiographic restenosis was defined < or =50% diameter stenosis at follow-up. Genotyping for an exon 2 polymorphism (+2,018) of IL-1RN (alleles 1 and 2) was based on a polymerase chain reaction technique. RESULTS: Allele 2 frequency was 0.28. Carriers of allele 2 had a significantly lower risk for angiographic restenosis, odds ratio (OR) of 0.78 (95% confidence interval, 0.63 to 0.97) and target vessel revascularization, OR of 0.73 (0.58 to 0.92) compared with noncarriers. Risk reduction was especially significant in patients <60 years (n = 696), with OR of 0.63 (0.43 to 0.91) for angiographic restenosis and 0.55 (0.39 to 0.78) for target vessel revascularization. CONCLUSIONS: Allele 2 of the IL-1ra gene was associated with a lower incidence of restenosis after coronary stenting, particularly in younger patients. This finding supports a role of inflammation in the development of restenosis after stent placement.

Aged↗

PubMed2000

HPA-1 and HPA-3 polymorphisms of the platelet fibrinogen receptor and coronary artery disease and myocardial infarction.

Platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa) plays a fundamental role in atherothrombosis. The human platelet antigen (HPA) -1 and the HPA-3 are the most extensively studied polymorphisms of GPIIIa and GPIIb, respectively. This study was designed to test, in a large population, the hypothesis that these polymorphisms represent a risk factor for the occurrence of coronary artery disease (CAD) and myocardial infarction (MI). Consecutive, angiographically examined patients with significant coronary stenoses but without symptoms or signs of old or acute MI constituted the group with CAD (CAD, n = 998) and those with old or acute MI constituted the group with MI (MI, n = 793). As controls served subjects, matched with patients for age and sex, with neither angiographic CAD nor symptoms or signs of MI (matched controls [MC], n = 340) as well as a group of blood donors without cardiac symptoms or signs of CAD (BD, n = 104). Genotype distribution was similar across the groups; HPA-1a/a: HPA-1a/b: HPA-1b/b was 75.0%: 22.1%: 2.9% in BD, 72.6%: 24.7%: 2.6% in MC, 70.5%: 26.8%: 2.7% in CAD, and 70.7%: 26.4%: 2.9% in MI; HPA-3a/a: HPA-3a/b: HPA-3b/b was 39.4%: 40.4%: 20.2% in BD, 33.5%: 50.0%: 16.5% in MC, 35.0%: 46.4%: 17.0% in CAD, and 37.1%: 48.0%: 16.5% in MI. There was no interaction between these polymorphisms, nor between each of these polymorphisms and other risk factors. Thus, the HPA-1 and HPA-3 polymorphisms are neither separately nor in concert associated with any measurable increase of the risk for CAD or MI in angiographically evaluated subjects.

Aged↗

PubMed1999

Polymorphism of platelet glycoprotein IIb and risk of thrombosis and restenosis after coronary stent placement.

Both glycoprotein (GP) IIb and IIIa of platelet fibrinogen receptor are polymorphic proteins. Unlike GPIIIa, there is little information about the clinical significance of the GPIIb polymorphism. We designed this prospective study to assess whether patients with the human platelet antigen (HPA)-3 polymorphism of GPIIb are more susceptible to developing thrombosis and restenosis after coronary stent placement. We included 2,178 consecutive patients with coronary artery disease who underwent intracoronary stent implantation, 789 (36.2%) with HPA-3a/a, 1,023 (47.0%) with HPA-3a/b, and 366 (16.8%) with HPA-3b/b genotype. The incidence of stent thrombosis was 1.7% in HPA-3a/a, 1.7% in HPA-3a/b, and 1.6% in HPA-3b/b patients (p = 0.999). The incidence of stent restenosis was 37.3% in HPA-3a/a, 36.2% in HPA-3a/b, and 34.6% in HPA-3b/b patients (p = 0.724). Event-free survival 1 year after stent placement was 76.1% for HPA-3a/a, 76.5% for HPA-3a/b, and 76.4% for HPA-3b/b patients (p = 0.968). We conclude that the HPA-3 polymorphism of platelet GPIIb is not associated with an increase in the risk of thrombosis and restenosis over 1 year after coronary stent placement. These data indicate that unlike the HPA-1 polymorphism of GPIIIa, the HPA-3 polymorphism of GPIIb may not serve as a useful genetic marker for the risk assessment of patients treated with intracoronary stenting.

Adult↗

PubMed1999

Unknown primary head and neck squamous cell carcinoma: molecular identification of the site of origin.

BACKGROUND: Unknown primary head and neck squamous cell carcinoma (HNSCC) presents as a cervical lymph node metastasis without identification of the primary tumor, despite thorough diagnostic work-up that includes physical examination, computed tomography, esophagoscopy, laryngoscopy, bronchoscopy, and multiple surveillance biopsies. We investigated whether the site of origin of the primary tumor could be localized in the upper aerodigestive tract mucosa by detection of genetic alterations identical to those found in metastatic lesions. METHODS: Microsatellite analysis was performed on metastatic tumors obtained from 18 patients with unknown primary HNSCC. Histologically benign surveillance biopsy specimens were also analyzed. Patients were followed up to 13 years with continuing surveillance for primary mucosal tumors. Most patients were treated with neck dissection followed by radiation therapy to the affected neck and ipsilateral Waldeyer's ring. RESULTS: In 10 (55%) of the 18 patients, at least one histopathologically benign mucosal biopsy specimen from defined anatomic sites (i.e., most likely sites for an occult primary tumor) demonstrated a pattern of genetic alterations identical to that present in cervical lymph node metastases. One patient harboring genetic alterations in the base of the tongue and two patients harboring genetic alterations in a tonsillar fossa subsequently developed HNSCC in the identical or adjacent mucosal region; all three of the primary head and neck mucosal tumors that eventually appeared between 1 and 13 years later in these patients had genetic changes identical to those in the benign mucosal biopsy specimens and in the metastatic lymph nodes. CONCLUSIONS: These data support the hypothesis that histopathologically benign mucosa of the upper aerodigestive tract may harbor foci of clonal, preneoplastic cells that are genetically related to metastatic HNSCC and that such mucosal sites are the sites of origin of unknown primary HNSCC. Microsatellite analysis may represent a clinically useful tool for determining such sites.

Carcinoma, Squamous Cell↗

PubMed1999

PlA polymorphism of platelet glycoprotein IIIa and risk of restenosis after coronary stent placement.

BACKGROUND: Platelets play a central role in the process of restenosis after percutaneous coronary interventions. A polymorphism of platelet glycoprotein IIIa (PlA) has been associated with a higher risk of coronary thrombosis. We designed this prospective study to test the hypothesis that PlA polymorphism of glycoprotein IIIa is associated with an increased risk for restenosis after coronary stent placement. METHODS AND RESULTS: The study included 1150 consecutive patients with successful coronary stent placement and 6-month follow-up with coronary angiography. The end point of the study was the incidence of angiographic restenosis (>/=50% diameter stenosis) at follow-up. Of the 1150 patients, 72.5% were homozygous for PlA1, 24.7% were heterozygous (PlA1/A2), and 2.8% were homozygous for PlA2. Patients with the PlA2 allele demonstrated a significantly higher restenosis rate than did those without (47% versus 38%; OR, 1.42; 95% CI, 1.09 to 1.84). The risk was highest in homozygous carriers of PlA2 (53.1% restenosis rate). After adjustment for several clinical and angiographic characteristics, the presence of the PlA2 allele remained a significantly independent risk factor for restenosis (adjusted OR, 1.35; 95% CI, 1.07 to 1.70). The influence of the PlA2 allele on restenosis was stronger in women. Women with PlA2 had a restenosis rate of 52% compared with the 33% incidence among women homozygous for PlA1 (OR, 2.21; 95% CI, 1.27 to 3.85). CONCLUSIONS: This study showed a significant association between the PlA polymorphism of glycoprotein IIIa and the risk of restenosis after coronary stent placement. The risk was more pronounced in patients homozygous for PlA2 allele and in female patients.

Adult↗

PubMed1999

Persistently negative HIV-1 antibody enzyme immunoassay screening results for patients with HIV-1 infection and AIDS: serologic, clinical, and virologic results. Seronegative AIDS Clinical Study Group.

OBJECTIVE: To describe persons with HIV infection and AIDS but with persistently negative HIV antibody enzyme immunoassay (EIA) results. DESIGN: Surveillance for persons meeting a case definition for HIV-1-seronegative AIDS. SETTING: United States and Canada. PATIENTS: A total of eight patients with seronegative AIDS identified from July 1995 through September 1997. MAIN OUTCOME MEASURES: Clinical history of HIV disease, history of HIV test results, and CD4 cell counts from medical record review; results of testing with a panel of EIA for antibodies to HIV-1, and HIV-1 p24 antigen; and viral subtype. RESULTS: Negative HIV EIA results occurred at CD4 cell counts of 0-230 x 10(6)/l, and at HIV RNA concentrations of 105,000-7,943,000 copies/ml. Using a panel of HIV EIA on sera from three patients, none of the HIV EIA detected infection with HIV-1, and signal-to-cut-off ratios were < or = 0.8 or all test kits evaluated. Sera from five patients showed weak reactivity in some HIV EIA, but were non-reactive in other HIV EIA. All patients were infected with HIV-1 subtype B. CONCLUSIONS: Rarely, results of EIA tests for antibodies to HIV-1 may be persistently negative in some HIV-1 subtype B-infected persons with AIDS. Physicians treating patients with illnesses or CD4 cell counts suggestive of HIV infection, but for whom results of HIV EIA are negative, should consider p24 antigen, nucleic acid amplification, or viral culture testing to document the presence of HIV.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Adenovirus-mediated gene transfer of the beta2-adrenergic receptor to donor hearts enhances cardiac function.

Gene transfer to modify donor heart function during transplantation has significant therapeutic implications. Recent studies by our laboratory in transgenic mice have shown that overexpression of beta2-adrenergic receptors (beta2-ARs) leads to significantly enhanced cardiac function. Thus, we investigated the functional consequences of adenovirus-mediated gene transfer of the human beta2-AR in a rat heterotopic heart transplant model. Donor hearts received 1 ml of solution containing 1 x 1010 p.f.u. of adenovirus encoding the beta2-AR or an empty adenovirus as a control. Five days after transplantation, basal left ventricular (LV) pressure was measured using an isolated, isovolumic heart perfusion apparatus. A subset of hearts was stimulated with the beta2-AR agonist, zinterol. Treatment with the beta2-AR virus resulted in global myocardial gene transfer with a six-fold increase in mean beta-AR density which corresponded to a significant increase in basal contractility (LV + dP/dtmax, control: 3152.1 +/- 286 versus beta2-AR, 6250.6* +/- 432.5 mmHg/s; n = 10, *P < 0.02). beta2-AR overexpressing hearts also had higher contractility after zinterol administration compared with control hearts. Our results indicate that myocardial function of the transplanted heart can be enhanced by the adenovirus-mediated delivery of beta2-ARs. Thus, genetic manipulation may offer a novel therapeutic strategy to improve donor heart function in the post- operative setting.

Adenoviridae↗

PubMed1998

Activated platelets induce monocyte chemotactic protein-1 secretion and surface expression of intercellular adhesion molecule-1 on endothelial cells.

BACKGROUND: Platelet/endothelium interaction plays an important role in the pathophysiology of inflammation and atherosclerosis. The role of platelets for monocyte chemotactic protein-1 (MCP-1) secretion and surface expression of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells has been assessed. METHODS AND RESULTS: Monolayers of human umbilical vein endothelial cells were incubated with nonstimulated or ADP-activated platelets for 6 hours, and secretion of MCP-1 and surface expression of ICAM-1 were determined by ELISA and flow cytometry, respectively. In the presence of ADP-activated platelets, both MCP-1 secretion and ICAM-1 surface expression were significantly increased compared with nonstimulated platelets (P<0.02). Activation of the transcription factor nuclear factor-kappaB (NF-kappaB) determined by electrophoretic mobility shift assay and kappaB-dependent transcriptional activity was enhanced in the presence of activated platelets. In addition, ADP-activated platelets induced MCP-1 and ICAM-1 promoter-dependent transcription. Liposomal transfection of a double-stranded kappaB phosphorothioate oligonucleotide, but not of the mutated form, inhibited MCP-1 secretion and surface expression of ICAM-1 on activated endothelium (P<0.05). CONCLUSIONS: The present study indicates that activated platelets modulate chemotactic (MCP-1) and adhesive (ICAM-1) properties of endothelial cells via an NF-kappaB-dependent mechanism. Platelet-induced activation of the NF-kappaB system might contribute to early inflammatory events in atherogenesis.

Arteriosclerosis↗

PubMed1998

Regulation of enzymes involved in anthocyanin biosynthesis in carrot cell cultures in response to treatment with ultraviolet light and fungal elicitors.

The accumulation of anthocyanins in cell cultures of Daucus carota L. and the enzymes involved in their biosynthesis were investigated under growth in the dark, continuous irradiation with UV light, incubation with elicitors from Pythium aphanidermatum, and elicitor treatment of UV-irradiated cells. Upon UV irradiation, anthocyanin accumulation was strongly enhanced, and the enzymes of the phenylpropanoid and flavonoid pathways, including the "late" enzymes cyanidin galactosyltransferase, cyanidin galactoside xylosyltransferase, cyanidin triglycoside sinapoyltransferase and sinapic acid glucosyltransferase, all showed transient increases in their activities. The time courses of the enzyme activities exhibited successive maxima with an ordered sequence corresponding to their position in the biosynthetic pathway, suggesting a coordinated induction of the entire set of enzymes. The key enzymes phenylalanine ammonia-lyase and chalcone synthase are regulated on a transcriptional level. Incubation of dark-grown carrot cells with fungal elicitors led to a rapid and transient induction of phenylalanine ammonia-lyase corresponding to the formation of 4-hydroxybenzoic acid, but the amount of anthocyanin did not increase and there was no enhancement of any of the enzyme activities which are part of the anthocyanin pathway, including the enzymes catalyzing glycosylation and acylation reactions. Treatment with UV light and elicitors resulted in a rapid induction of the phenylpropanoid pathway, whereas the inducing effect of UV light on the anthocyanin content, on chalcone synthase and on the enzymes catalyzing the final steps of anthocyanin biosynthesis was suppressed. These results indicate a coordinated regulation of the enzymes involved in anthocyanin biosynthesis, an independent inducibility of the phenylpropanoid pathway, and a hierarchy of the different effectors, as shown by the dominating role of the elicitor-signal over the UV stimulus.

Anthocyanins↗

PubMed1998

Control of the synovium in haemophilia.

Adequate factor substitution is a prerequisite for successful conservative or operative treatment of haemophilic synovitis. Subsequent prophylactic factor substitution can prevent further joint problems in the future. Orthopaedic treatment regimes are dependent on the classification of the synovitis and the stage of the arthropathy. Synovitis can be classified into acute and chronic forms. The arthropathy is classified according to Arnold and Hilgartner. When the synovitis has already become chronic, early arthroscopic synovectomy is recommended in order to prevent the otherwise inexorable progress of the arthropathy. Failure to treat in the early phase of the pathology causes problems in the correction of further stages. The progression of the joint disease can be shown both clinically and radiologically as the arthropathy develops, and influences the treatment.

Hemophilia A↗

PubMed1998

Micronucleus induction in V79 cells after direct exposure to whole cigarette smoke.

Previous investigations on the effects of cigarette smoke on cultured cells have used mainly smoke condensate dissolved in culture medium. A system has been designed which allows direct exposure of cells to fresh cigarette smoke, without an intervening layer of growth medium between the cells and the smoke. Preliminary results have been obtained which demonstrate the viability of the system. V79 cells were cultured on porous membranes (Transwell; Costar). During smoke exposure only the lower surface of each Transwell is supplied with culture medium from the bottom of the culture chambers. In this way the cells had direct contact with the atmosphere at the upper surface and could be exposed directly to the test compound. The constructed exposure system consists of a smoke generator and an exposure unit containing six Transwells, the latter contained in an incubator. Cigarette smoke was generated using a standard 2 s, 35 ml puff once per min. The puff is diluted with conditioned air from the incubator and injected into the exposure unit. Following exposure of the cells to air only for 3 h there was no effect upon V79 cell viability. However, after exposure to smoke containing between 88 and 224 mg/m3 particulate matter, an inhibition of cell proliferation and induction of micronuclei was measured. When a Cambridge filter pad was placed between the cigarette and the cell exposure system to remove particulate matter cell proliferation was also reduced and an increased frequency of micronuclei above the control value was measured.

Aerosols↗

PubMed1998

[An alternative dorsal fusion technique after transoral dens resection in basilar impression with atlas assimilation].

Current therapy of basilar impression includes transoral dens resection. The essential disadvantage of this procedure is the instability of C1/C2 due to loss of the transverse ligament. We describe two patients in whom this instability was treated by modified screwing. Using MAGERL-screws between C0-C2 an interposition of an iliac graft between the occiput and the arc of C2 was made. Neurological symptoms improved in both patients postoperatively. In both cases stable fusion C0/C2 was achieved with an additional treatment with a HALO-fixateur for eight weeks. In our opinion the combined transoral/dorsal procedure is most suitable and efficient in treatment of basilar impressions. By this approach both, decompression of the myelon as well as stable fusion C0/C2, is achieved.

Adolescent↗

PubMed1998

Human parvovirus B19: prevalence of viral DNA in volunteer blood donors and clinical outcomes of transfusion recipients.

BACKGROUND AND OBJECTIVES: Blood donor units are not screened for human parvovirus B19 (B19) even though it can be acquired via blood products. We estimated the prevalence of B19 in a US volunteer blood donor population and determined the clinical outcomes of transfusion recipients. MATERIALS AND METHODS: Donor units were screened for B19 DNA by PCR, and positive units analyzed by EIA for B19 Ig. Unit usage was determined and recipient chart review conducted. RESULTS: B19 DNA was detected in 11/9, 568 allogeneic units (0.1%), of which 3 had no measurable B19 Ig. One individual developed anemia consistent with B19 infection after receiving a DNA+ unit lacking B19 Ig. CONCLUSIONS: The apparent low incidence of disease in patients transfused with B19 DNA+ components may be due to coexistence of neutralizing antibodies in donors and/or recipients.

Anemia↗

PubMed1997

Induction of cytokine expression in leukocytes in acute myocardial infarction.

OBJECTIVES: This study sought to investigate whether cytokine expression in leukocytes may be induced by plasma from the reperfused heart of patients with an acute myocardial infarction (MI). BACKGROUND: Reperfusion in acute MI is associated with deleterious local and systemic inflammatory responses that are regulated by cytokines. Induction of cytokine expression in resident leukocytes could contribute to inflammatory responses of the ischemic and reperfused heart. METHODS: Blood samples of 10 patients with an acute MI were obtained simultaneously from the coronary sinus and the aorta before and 5 min after recanalization of the coronary occlusion. Ten patients with elective percutaneous transluminal coronary angioplasty served as a control group. We incubated leukocytes from healthy donors with plasma samples and analyzed mRNA expression of interleukin (IL)-1 beta, IL-6, IL-8 and tumor necrosis factor-alpha (TNF-alpha) by Northern blot analysis. RESULTS: In patients with an acute MI, plasma obtained from the coronary sinus after recanalization increased the mRNA expression of IL-1 beta and IL-8 compared with that of plasma before recanalization (median [quartiles] difference before vs. after recanalization: 34.5 [4, 137], p = 0.017, for IL-1 beta; 18.5 [4, 35], p = 0.032, for IL-8) and simultaneously obtained aortic plasma (median [quartiles] coronary sinus-aortic differences after recanalization: 45.5 [-3, 115], p = 0.021, for IL-1 beta; 16 [4, 52], p = 0.005, for IL-8). No induction of IL-6 and TNF-alpha expression could be observed. No changes found in the study patients were detectable in the control group. CONCLUSIONS: Plasma from the ischemic and reperfused heart stimulates the expression of IL-1 beta and IL-8 in leukocytes. Therefore, leukocyte-derived cytokines may contribute to the regulation of cardiac inflammatory responses in patients with an acute MI.

Adult↗

PubMed1997

Exercise capacity and mid-term survival in patients with tricuspid atresia and complex congenital cardiac malformations after modified Fontan-operation.

OBJECTIVE: Continued follow-up of the Fontan population group is mandatory in order to evaluate the best approach for long term treatment. We studied exercise capacity and survival in patients with either right atrial to right ventricular (Fontan-Bjoerk, RA-RV) anastomosis or right atrial to pulmonary artery (RA-PA) connection. METHODS: Between January 1980 and December 1995 Fontan-Bjoerk modifications were performed in 73 patients with tricuspid atresia. A RA-PA anastomosis (performed either with direct atrio-pulmonary connection or with a lateral tunnel of autologous atrial tissue) was used in 118 patients with single ventricle or complex cardiac malformations. Using bicycle ergospirometry and impedance cardiography standard variables of exercise testing were measured in 15 patients with RA-RV and in 18 patients with RA-PA connection. A group of 23 healthy pupils served as controls. RESULTS: Follow-up was complete for 97.9% (n = 187) of all operated patients. Survival (% mean +/- SEM) at 5, 10 and 15 years was 89.3 +/- 3.6, 76.8 +/- 0.6 and 63.6 +/- 10.5 for RA-RV connection and 80.2 +/- 4.0, 75.3 +/- 4.5 and 64.6 +/- 10.7 for RA-PA connection (P = 0.12) respectively. Exercise capacity was tested after a median time of 6.0 (0.8-19.8) years after Fontan operation in RA-RV and of 7.8 (4.3-18.2) years in RA-PA patients. Total work load was equal in the two Fontan groups, but it was below normal. Heart rate, respiratory rate, oxygen uptake and ventilatory equivalent for oxygen were not different between the two Fontan groups. Cardiac index and stroke volume index were consistently lower at anaerobic threshold and at maximal exercise in RA-PA patients compared with controls. CONCLUSION: Survival analysis between RA-RV and RA-PA Fontan connection failed to demonstrate a better outcome for patients with either Fontan modification. Although there was a tendency for RA-RV connection to adapt cardiac output more efficient to exercise compared with RA-PA patients, total work load and ventilatory equivalent was not significantly different between the two Fontan modifications. We conclude, that by incorporation of a residual subpulmonary ventricular chamber within the Fontan circulation no additional benefit for exercise capacity could be observed.

Adolescent↗