[Heparin-induced thrombocytopenia type II (HIT II) : A medical-economic view]

BACKGROUND

In the context of inpatient and increasingly ambulatory thrombosis prophylaxis, heparins have been recognised as standard therapy for decades. In addition to the therapeutic benefit, therapy with heparins also entails the risk of undesirable side effects, such as bleeding and thrombocytopenia. Heparin-induced thrombocytopenia (HIT II) is deemed a serious side effect.

AIM

In the following work, HIT II is subjected to a medico-economic consideration (treatment, pharmaceuticals, subsequent costs due to possible complications) and, with regard to a possible HIT II prophylaxis, aspects of increasingly respected patient safety are also considered.

METHODS

In the context of a literature search the active ingredients argatroban and danaparoid, which are approved for HIT II treatment, were evaluated.

RESULTS

HIT II - especially in combination with thromboembolic complications - represents a medical-economic burden for the hospital. Although this is only an orientation guide, it shows that HIT II syndrome is not adequately cost-covered by the G‑DRG system. An early thrombosis prophylaxis with argatroban/danaparoid for HIT II risk patients should therefore be taken into account for medical-related as well as patient safety-relevant aspects. According to experience, the pharmaceutical supply for these medically needed products (anticoagulants) should be ensured for reasons of patient safety.

CONCLUSION

The risk of an immunological response to heparin therapy is known. Within the context of increased patient safety, thrombosis prophylaxis should be issued with a risk-adjusted prophylaxis.

[Perioperative risk and mortality after major surgery]

Although anesthesia-associated mortality has been significantly reduced down to 0.00068-0.00082% over the last decades, recent studies have revealed a high perioperative mortality of 0.8- 4%. Apart from anesthesia and surgery-induced major complications, perioperative mortality is primarily negatively influenced by individual patient comorbidities. These risk factors predispose for acute critical incidents (e.g., myocardial infarction); however, the majority of fatal complications are a result of slowly progressing conditions, particularly infections or the sequelae of systemic inflammation. This implicates a broad window of opportunity for the detection and treatment of slow-onset complications to improve the perioperative outcome. The term "failure to rescue" (FTR), i.e., the proportion of patients who die from major complications compared to the number of all patients with complications, has been introduced as a valid indicator for the quality of perioperative care. Growing evidence has already shown that FTR is an underestimated factor in perioperative medicine accounting for or at least being involved in the development of postoperative mortality. While the incidence of severe postoperative complications amazingly does not show much variation between hospitals, FTR shows significant differences implying a major potential for improvement. With 14 million surgical procedures per year in Germany, a postoperative mortality of approximately 1% and an avoidable FTR rate of 40% mean that there are an estimated 60,000 preventable deaths per year. Hence, in the future it will be imperative to (1) identify patients at risk, (2) to prevent the development of postoperative complications with the use of adequate adjunctive therapeutic strategies, (3) to establish surveillance and monitoring systems for the early detection of postoperative complications and (4) to treat postoperative complications efficiently and in time when they arise.

[Characteristics of Focal Degenerative Cartilage Lesions in the Knee Joint. A Radiologic, Spectroscopic, Histological and Biochemical Study]

OBJECTIVE

The aim of this study was to perform a macroscopic, spectroscopic and biochemical/histological examination of the defect margins of grade IIIb cartilage lesions in the patella, the medial femoral condyle, the corresponding articular surface and the remaining cartilage surfaces of the knee joint. Our null hypothesis was that there would be no difference in characteristics between the cartilage surrounding the defect, the corresponding articular surface and the remaining articular surfaces of the knee joint on the one hand and the cartilage within the defect on the other.

METHOD

The study included ten patients treated for focal cartilage lesions (ICRS classification grade IIIb) by autologous cartilage transplantation (ACT). All patients underwent a preoperative magnetic resonance imaging scan (1, 5 T). The articular cartilage lesions were classified pursuant to the recommendations of the International Cartilage Repair Society (ICRS). During the arthroscopic procedure, spectroscopic examinations were performed to measure the degree of cartilage degeneration in a total of 14 defined areas including the defect itself and the region of the defect margins. Biopsies for a histological and biochemical examination (collagen II, glycosaminoglycan, DNA) were taken from the centre of the defect and the defect margins that seemed to be intact on macroscopic examination.

RESULTS

All knee joints had focal grade IIIb cartilage lesions with an intact margin and an intact corresponding articular surface. The readings obtained on spectroscopic examination both in the defect, the apparently intact margins, the corresponding articular surface and all other examined areas of the knee suggested that severe degenerative changes had already occurred in the cartilage. The histological and biochemical examinations of the residual cartilage in the centre of the defect and the apparently intact margins revealed no significant differences.

CONCLUSIONS

Focal cartilage lesions frequently occur in the main weight-bearing zones of the patella and the medial femoral condyle. If they are the result of degenerative changes in the knee joint, the residual cartilage in the defect does not differ from the cartilage of the defect margins, the corresponding articular surface and the other cartilage surfaces. This leads to the conclusion that focal cartilage defects seen in degenerative joint damage are only one aspect of general joint degeneration.

[Patient Satisfaction as a Measure of Quality of Patient Care - Comparison between a University Hospital and a General Hospital]

Objective: The aim of the study was to compare the satisfaction of patients of a general hospital with a university hospital. A patient satisfaction index was calculated based on the assessed levels of satisfaction. In general, higher satisfaction could lead to increased competitiveness and improved cost efficiency for achieving profitability. Methods: The authors developed and administered a questionnaire on distinct parameters presumed to reflect the quality of the hospital stay to patients of a university hospital (University Hospital of Bonn, UKB, 1 224 beds) and a general hospital (Johanniterkrankenhaus, Bonn, JKH, 364 beds). Data were collected anonymously. Patient satisfaction and the relative importance of each parameter were assessed. The quotient of both parameters yields the patient satisfaction index (PZI). In order to account for possible differences in patient demands, statistical analysis was performed. Results: The demands and wishes, satisfaction and importance of the retrieved parameters did not differ significantly between the patients of the hospitals in any of aspects assessed (information, participation, contact and comfort during the hospital-stay). The study showed that communication and the contact to physicians and nurses was significantly more important for the patients than comfort (each p<0.001). The highest PZI were found in the categories entertainment (UKB 1.02; JKH 1.25) and contact to the nursing personnel (PZI UKB 0.94; PZI JKH 0.96). The standard of medical-technical care (UKB 0.93; JKH 0.95) was also highly ranked by patients of both hospitals. Needs for improvement related especially to the communication of errors (UKB 0.33; JKH 0.31). Discussion: Surveillance of patient wishes and criticism may result in a more patient-oriented care on a daily basis. Scrutinizing the resources employed may lead to more efficient use of resources and personnel and thus help cut costs and improve the attractiveness of hospitals.

Regulation of p53 under hypoxic and inflammatory conditions in periodontium

OBJECTIVES

Different studies suggest that inflammation as well as hypoxia leads to an increase of p53 protein levels. However, the implication of p53 during oral inflammatory processes is still unknown. The aim of this study was therefore to investigate the effect of hypoxia and inflammation on p53 regulation in human periodontium in vitro and in vivo.

MATERIALS AND METHODS

Under hypoxic and normoxic conditions, human primary periodontal ligament (PDL) fibroblasts (n = 9) were stimulated with lipopolysaccharides (LPS) from Porphyromonas gingivalis (P.g.), a periodontal pathogenic bacterium. After different time points, cell viability was tested; p53 gene expression, protein synthesis, and activation were measured using quantitative RT-PCR, immunoblotting, and immunofluorescence. Moreover, healthy and inflamed periodontal tissues were obtained from 12 donors to analyze p53 protein in oral inflammatory diseases by immunohistochemistry.

RESULTS

LPS-P.g. and hypoxia initially induced a significant upregulation of p53 mRNA expression and p53 protein levels. Nuclear translocation of p53 after inflammatory stimulation supported these findings. Hypoxia first enhanced p53 levels, but after 24 h of incubation, protein levels decreased, which was accompanied by an improvement of PDL cell viability. Immunohistochemistry revealed an elevation of p53 immunoreactivity in accordance to the progression of periodontal inflammation.

CONCLUSIONS

Our data indicate that p53 plays a pivotal role in PDL cell homeostasis and seems to be upregulated in oral inflammatory diseases.

CLINICAL RELEVANCE

Upregulation of p53 may promote the destruction of periodontal integrity. A possible relationship with carcinogenesis may be discussed.

Antibiotic consumption after implementation of a procalcitonin-guided antimicrobial stewardship programme in surgical patients admitted to an intensive care unit: a retrospective before-and-after analysis

PURPOSE

To analyse antibiotic use density (AD)--World Health Organization defined daily doses/1,000 patient-days--before and after implementation of a local antimicrobial stewardship programme (ASP) in conjunction with a procalcitonin (PCT)-guided protocol in a surgical intensive care unit (ICU).

METHODS

In this retrospective observational study, data on 2,422 ICU patients between 2010 and 2012 were analysed. In 2011, an ASP in conjunction with a PCT protocol had been introduced into clinical practice. In a multivariate analysis, hospital mortality, length of stay (LOS) in hospital and ICU LOS were adjusted for effects from effective cost weight, gender, and age. AD and changes in the use of antibiotic classes were analysed.

RESULTS

AD decreased from 1,005.0 in 2010 to 791.9 in 2012 which is a total reduction of 21.2%. Consumption of aminoglycosides, cephalosporins and quinolones showed a marked reduction, whereas the use of penicillins did not change significantly. The multivariate models revealed no relevant changes in mortality rate, ICU LOS and hospital LOS.

CONCLUSIONS

Implementation of an ASP in conjunction with a PCT protocol in 2011 was associated with a marked decrease in total AD and led to a significant change in the spectrum of antibiotics. Clinical outcomes appeared to remain unchanged over the study period.

Pre-conditioning with synthetic CpG-oligonucleotides attenuates myocardial ischemia/reperfusion injury via IL-10 up-regulation

The aim of the study was to investigate whether pre-conditioning with CpG-oligodeoxynucleotides (CpG-ODN) may change cardiac ischemia/reperfusion (I/R)-dependent inflammation and modulates infarct size and cardiac performance. WT and TLR9-deficient mice were pre-treated with 1668-, 1612- and H154-thioate or D-Gal as control. Priming with 1668-thioate significantly induced inflammatory mediators in the serum and a concomitant increase of immune cells in the blood and spleen of WT mice. Furthermore, it induced myocardial pattern recognition receptors and pro-inflammatory cytokines peaking 2 h after priming and a continuous increase of IL-10. 16 h after pre-conditioning, myocardial ischemia was induced for 1 h. Infarct size determined after 24 h of I/R was reduced by 75 % due to pre-conditioning with 1668-thioate but not in the other groups. During reperfusion, cytokine expression in 1668-thioate primed mice increased further with IL-10 exceeding the other mediators by far. These changes were observed neither in animals pre-treated with 1612- or H154-thioate nor in TLR9-deficient mice. The 1668-thioate-dependent increase of IL-10 was further supported by results of a micro-array analysis 3 h after begin of reperfusion. Block of IL-10 signaling increased I/R size and prevented influence of priming. In the group pre-treated with 1668-thioate, cardiac function was preserved 24 h, 14 days and 28 days after I/R, whereas animals without pre-conditioning exhibited impaired heart function 24 h and 14 days after I/R. The excessive 1668-thioate-dependent IL-10 up-regulation during pre-conditioning and after I/R seems to be the key factor for reducing infarct size and improving cardiac function. This is in agreement with the finding that IL-10 block prevents cardioprotection by pre-conditioning.

[Evaluation of cartilage degeneration by near infrared spectroscopy (NIRS): methodical description and systematic literature review]

Damage to hyaline cartilage is the most important pathophysiological tool in the development of osteoarthritis. Cartilage lesions are the most frequent pathological findings during arthroscopic operations. Arthroscopies as well as magnetic resonance tomography are gold standards for detection of cartilage lesions. But the arthroscopic evaluation of cartilage lesions is descriptive and subjective only. The surgeon is able to differentiate between intact cartilage surface, softening, superficial or deep fissure or flake and finally a complete defect. In routine arthroscopy the grading mostly is made by use of different scores [e.g. ICRS (International Cartilage Repair Society), Outerbridge, Insall, Jäger-Wirth or others]. Because the arthroscopic evaluation is subjective the reliability of this method is poor. Spectroscopic methods are established for evaluation of different tissue diseases in different indications. NIRS (near infrared spectroscopy) has become an important method for medical diagnostics in the last years. NIR is very energy-rich and suitable for glass fibre transport without relevant reduction. Insofar this technology may be ideal for endoscopic procedures. Our systematic literature review reveals that NIRS is a sufficient method for an objective diagnosis of cartilage lesions. In the current work we demonstrate an NIRS-based device for intraoperative, real-time cartilage evaluation. Furthermore, we discuss the possible clinical consequences from such measurements.

[Traumatic tricuspid valve insufficiency with right-to-left shunt: bridging using extracorporeal venovenous membrane oxygenation]

The case of a young male motor vehicle driver is reported who suffered multiple trauma in a car accident with pulmonary and cardiac contusions. In the course of severe pneumonia and traumatic tricuspid valve insufficiency a right-to-left shunt with refractory hypoxemia developed across a pre-existing atrial septal defect (ASD). The patient could be successfully treated by the combination of extracorporeal membrane oxygenation for bridging, interventional ASD occlusion and in the long-term by operative reconstruction of the tricuspid valve.

Cardiac remodeling as a consequence and cause of progressive heart failure

Natural history studies in heart failure have shown that increases in left ventricular (LV) volume and LV mass are directly related to future deterioration in LV performance and a less favorable clinical course. Despite the recognized importance of remodeling in heart failure, very little is known about the basic mechanisms that lead to cardiac remodeling. In this review, we will summarize recent clinical and experimental studies that highlight the importance of the remodeling process during the progression of heart failure. The intent of this review is to provide an integrated view of the mechanisms that contribute to LV remodeling at the cellular level, the myocardial level, and the level of the chamber.

Antagonism of lipopolysaccharide-induced blood pressure attenuation and vascular contractility

OBJECTIVE

Aim was to assess whether lipopolysaccharide (LPS)-induced decrease of total peripheral resistance depends on Toll-like receptor (TLR)4 signaling and whether it is sensitive to NO-synthase or TLR4 antagonists.

METHODS AND RESULTS

C3H/HeN mice (control), expressing a functional, and C3H/HeJ mice, expressing a nonfunctional TLR4, were compared. LPS (20 mg/kg) was injected i.p. 6 hours before hemodynamic measurements. L-NAME and SMT, inhibitors of NO production, and Eritoran, a TLR4 antagonist, were tested for their impact on vascular contractility. Aortic rings were incubated for 6 hours with or without LPS (1 microg/mL), or with LPS+Eritoran (2 microg/mL) and their phenylephrine-induced contractility was measured using a myograph. The expression of cytokines in aortic tissue was examined by real-time polymerase chain reaction. In control mice LPS induced a significant decrease of blood pressure and an increase of heart rate, whereas C3H/HeJ remained unaffected. LPS induced an increase of cytokine expression and a depression of vascular contractility only in control mice but not in C3H/HeJ. L-NAME and SMT increased contractility in all rings and restored LPS-dependent depression of contractility. Eritoran prevented LPS-induced loss of contractility.

CONCLUSIONS

LPS upregulates cytokine expression via TLR4 and induces attenuation of smooth muscle contractility which can be effectively antagonized.

Role of Toll-like receptor 4 for the pathogenesis of acute lung injury in Gram-negative sepsis

BACKGROUND AND OBJECTIVE

Proinflammatory cytokines as well as nitric oxide (NO) play a major role in mediating the response to lipopolysaccharide (LPS). The present study tested the hypothesis that LPS induces proinflammatory cytokines in the lung via the Toll-like receptor 4 (TLR4)/CD14 signalling cascade.

METHODS

Control mice and TLR4-deficient (TLR4-D) mice were used to test TLR4-mediated effects of LPS. Both strains received either Escherichia coli LPS (20 mg kg-1 intraperitoneal) or saline and their lungs were collected at different time points. Pulmonary nuclear factor kappaB (NFkappaB) activation was investigated with electromobility shift assay. mRNA expression of inflammatory mediators and their corresponding receptors were detected with Ribonuclease Protection Assay. Protein expression was detected by ELISA and western blotting. Inducible NO synthase (iNOS) expression was monitored by RT-PCR and iNOS activity by conversion of l-arginine to citrulline. Immune cells were sampled by bronchoalveolar lavage (BAL) and classified.

RESULTS

LPS application induced CD14-, but not TLR4 protein expression in control mice. Activation of pulmonary NFkappaB was observed within 60 min in control, but not in TLR4-D mice. Six hours of LPS administration induced a significant increase in pulmonary tumour necrosis factor alpha-, interleukin-1beta- and interleukin-6 mRNA and protein expression in control mice compared to TLR4-D mice. Furthermore, LPS induced a significantly higher increase of the iNOS expression and catalytic activity in control mice than in TLR4-D mice. BAL revealed an increase in total cell count in all LPS treated mice.

CONCLUSION

Our findings suggest that TLR4 plays a key role for regulating the expression of relevant cytokines within the lung during endotoxic shock.

Toll-like receptor (TLR) 4 polymorphisms are associated with a chronic course of sarcoidosis

The aetiology of sarcoidosis, an inflammatory granulomatous multi-system disorder, is unclear. It is thought to be the product of an unknown exogenous antigenic stimulus and an endogenous genetic susceptibility. Toll-like receptors (TLR) are signal molecules essential for the cellular response to bacterial cell wall components. Lipopolysaccharide (LPS), for example, binds to TLR 4. Two different polymorphisms for the TLR4 gene (Asp299Gly and Thr399Ile) have been described recently. This leads to a change in the extracellular matrix function of TLR4 and to impaired LPS signal transduction. We genotyped a total of 141 Caucasian patients with sarcoidosis and 141 healthy unrelated controls for the Asp299Gly and Thr399Ile polymorphisms in the TLR4 gene. The mutations were identified with polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis. Among sarcoidosis patients the prevalence for each Asp299Gly and Thr399Ile mutant allele was 15.6% (22/141). In the control group the prevalence was 5.67% (8/141) (P = 0.07). In the subgroup of patients with acute sarcoidosis there was no difference in the control group (P = 0.93), but there was a highly significant association between patients with a chronic course of sarcoidosis and TLR4 gene polymorphisms (P = 0.01).

Myocardial cytokine gene expression is higher in aortic stenosis than in idiopathic dilated cardiomyopathy

OBJECTIVE

To investigate cytokine gene expression in patients with aortic valve stenosis (AS) and with idiopathic dilated cardiomyopathy (DCM), and to correlate wall stress with myocardial proinflammatory cytokine gene expression.

METHODS

Human left ventricular (LV) myocardial biopsies were obtained for subsequent reverse transcription polymerase chain reaction of tumour necrosis factor alpha (TNFalpha), interleukin (IL)-1beta, and IL-6 mRNA. The study population consisted of 24 patients with AS and 10 patients with idiopathic DCM.

RESULTS

Patients with AS had a larger ejection fraction (56 (5) v 37 (4)%, p < 0.01), smaller LV end diastolic volumes (146 (11) v 267 (21) ml, p < 0.01), and lower end systolic wall stress (44 (7) v 112 (11) kdyn/cm2, p < 0.001). Upregulation of TNFalpha, IL-1beta, and IL-6 gene expression was detected in both groups. However, TNFalpha gene expression was significantly higher in AS than in DCM (p = 0.009). No correlation was found between haemodynamic parameters and TNFalpha gene expression. In patients with AS there was a strong inverse relation between circulating TNFalpha and TNFalpha gene expression (r = -0.685, p = 0.014), between circulating TNFalpha and IL-1beta gene expression (r = -0.664, p = 0.018), and between soluble TNF receptor 2 and TNFalpha gene expression (r = -0.685, p = 0.020). Myocardial gene expression of TNFalpha was significantly higher in patients with well compensated AS than in patients with decompensated AS (p = 0.017). Similarly, patients with decompensated DCM were characterised by significantly lower TNFalpha gene expression than were patients with well compensated DCM (p = 0.011).

CONCLUSION

TNFalpha gene expression is significantly higher in patients with pressure overload than in normal hearts, in patients with idiopathic DCM, and in patients with compensated versus decompensated heart failure. Secondly, in patients with AS proinflammatory cytokine gene expression did not affect systolic performance. The higher TNFalpha gene expression in patients with compensated heart failure suggests that cytokine gene expression has an adaptive role in the early phase of LV remodelling.

Effect of mutation of amino acids 246-251 (KRKHKK) in HSP72 on protein synthesis and recovery from hypoxic injury

Heat shock protein (HSP)72, the inducible form of HSP70, protects cells against a variety of injuries, but underlying mechanisms are poorly defined. To investigate the protective effects of HSP72, multiple clones expressing wild-type (WT) HSP72 and two mutants with defective nucleolar and nuclear localization (M45 and 985A, respectively) were made with the tet-off system in C2C12 cells. Four different parameters of cell function/injury were examined after simulated ischemia: protein synthesis, polysome formation, DNA synthesis, and lactate dehydrogenase (LDH release). Overexpression of WT HSP72 was also compared to nontransfected C2C12 cells. As expected, overexpression of HSP72 protected against simulated ischemia and reoxygenation for all parameters. In contrast, both M45 and 985A showed abnormal protein synthesis and polysome formation, both after simulated ischemia and under control conditions. Total RNA was slightly reduced in M45 and 985A at baseline, but 1 h after hypoxia, RNA levels were protected in all clones but significantly decreased in nontransfected C2C12 cells. Clones expressing 985A had nuclear retention of mRNA, suggesting that HSP72 is needed for nuclear export of RNA. All clones, both WT and mutant, had protection of DNA synthesis compared to C2C12 cells, but 985A had greater release of LDH after injury than any other group. These results support a multifactoral protective effect of HSP72, some aspects dependent on nuclear localization with stress and some not. The protection of protein synthesis and polysome formation, and abnormalities in these with the mutants, support a role for HSP72 in these processes both in the normal cell and in injury.

[Cytokines and heart failure]

Chronic heart failure is a major cause for mortality and morbidity in western civilizations. Previous hypothesises regarding the pathogenesis of chronic heart failure did not sufficiently explain the aetiology and the progression of the disease. However, it has been shown that a group of peptides called cytokines are expressed during chronic heart failure and that cytokines might play an important role for the pathogenesis. The expression of cytokines can be modulated from specific ACE-inhibitors as well as from different beta-blockers and angiotensin type 1 antagonists. Numerous investigations have shown that cytokines depress left ventricular function and can be responsible for different characteristics of chronic heart failure. The present article resumes experimental and clinical investigations and recent pharmacologic attempts for the treatment of chronic heart failure. The previous results demonstrate the importance to further investigate anti-inflammatory approaches to treat chronic heart failure.

Versorgung von Patienten mit chronischem orofazialem Schmerz

OBJECTIVE

The aim of this study was to evaluate the significance attributed by dental and maxillofacial surgeons to the ambulatory management of chronic orofacial pain syndromes.

MATERIALS AND METHODS

All the dentists and oral and maxillofacial surgeons working in ambulatory capacities within a county of the German Rhine Area were asked to answer a questionnaire on demographic data, diagnostic and therapeutic principles, and the use of analogue scales, surgical, minimal-invasive or pharmacological procedures.

RESULTS AND DISCUSSION

Seventy-two ambulatory institutions reported 985 patients suffering from temporomandibular disorders (40.2%), headache-syndromes associated with facial pain (18.2%), and atypical odontalgia respectively phantom tooth pain (17.0%). Patients were characterized by prior dental treatment or trauma (41.9%), female gender (66.8%), middle age (81.1%, 20-60 years), very frequent change of therapists (54.6%) and long-term perseverance of pain (61.1% >6 months). Only 7% of therapists used visual or numerical analogue scales to assess pain intensity. Therapeutic procedures consisted of analgesics (15.7%) and further surgical procedures (47.7%). Pain therapists were rarely involved (12.5%).

CONCLUSION

Dental and maxillofacial surgeons should apply an interdisciplinary and multimodal approach to diagnostics and therapy at an earlier stage in order to optimize the pain management of patients with chronic orofacial pain.

Inducible activation of c-Myc in adult myocardium in vivo provokes cardiac myocyte hypertrophy and reactivation of DNA synthesis

c-Myc, a protooncogene, mediates both proliferative and cellular growth in many cell types. Although not expressed in the adult heart under normal physiological conditions, Myc expression is rapidly upregulated in response to hypertrophic stimuli. Although Myc is capable of sustaining hyperplastic growth in fetal myocytes, the effects of its re-expression in adult postmitotic myocardium and its role in mediating cardiac hypertrophy are unknown. To determine the effects of de novo Myc activity in adult postmitotic myocardium in vivo, we created a novel transgenic model in which Myc is expressed and inducibly activated specifically in cardiac myocytes. Activation of Myc in adult myocardium was sufficient to reproduce the characteristic changes in myocyte size, protein synthesis, and cardiac-specific gene expression seen in cardiac hypertrophy. Despite the increased cardiac mass, left ventricular function remained normal. Activation of Myc also provoked cell cycle reentry in postmitotic myocytes, which led to increased nuclei per myocyte and DNA content per nuclei.

In vivo expression of proinflammatory mediators in the adult heart after endotoxin administration: the role of toll-like receptor-4

Tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and nitric oxide (NO) may play a role in lipopolysaccharide (LPS)-induced cardiac depression. Toll-like receptor-4 (TLR-4) mediates the cytokine response to LPS in immune cells. TLR-4 also is expressed in human and murine myocardial tissue. Therefore, the hypothesis that LPS induces proinflammatory cytokines in the heart via TLR-4 was tested. C3H/HeJ (TLR-4 deficient) and C3HeB/FeJ mice were studied. LPS induced a robust increase in myocardial TNF-alpha and IL-1beta mRNA in C3HeB/FeJ mice. The response in C3H/HeJ mice was blunted and delayed. Myocardial TNF-alpha and IL-1beta protein levels were higher in C3HeB/FeJ mice, as were inducible NO synthase protein and NO production. Activation of myocardial NF-kappaB was observed within 30 min in C3HeB/FeJ mice but not in C3H/HeJ mice. These findings suggest that myocardial TLR-4 is involved in signaling cytokine production within the heart during endotoxic shock.

Functional significance of hemodynamic overload-induced expression of leukemia-inhibitory factor in the adult mammalian heart

BACKGROUND

Leukemia-inhibitory factor (LIF) is a member of the interleukin-6 family of cytokines that utilize gp130 as a common signaling component. In the present study, we examined the mechanisms that govern LIF expression and functional effects in the adult heart.

METHODS AND RESULTS

LIF mRNA and protein biosynthesis were examined in the adult feline heart after hemodynamic overloading ex vivo. Both LIF mRNA and protein expression were detected within 60 to 90 minutes after hemodynamic overloading. Studies in isolated adult cardiac myocytes showed that these cells synthesized both LIF mRNA and protein. The functional effects of LIF in the heart were demonstrated by studies that showed that LIF stimulation led to a significant increase in general protein synthesis and an increase in sarcomeric protein synthesis. Pretreatment with LIF also protected the cells against hypoxia/reoxygenation-induced cardiac myocyte apoptosis and cellular injury. Finally, LIF had no effect on isolated cardiac myocyte cell motion.

CONCLUSIONS

Hemodynamic overload is a sufficient stimulus for LIF expression in the adult mammalian heart. Given that LIF confers both hypertrophic and cytoprotective responses in adult cardiac myocytes, this study suggests that the expression of LIF within the heart may play an important role in mediating homeostatic responses within the myocardium.

Polarization Lidar: Correction of instrumental effects

An algorithm for correcting instrumental effects in polarization lidar studies is discussed. Cross-talk between the perpendicular and parallel polarization channels and imperfect polarization of the transmitted laser beam are taken into account. On the basis of the Mueller formalism it is shown that - with certain assumptions - the combined effects of imperfect polarization of the transmitted laser pulse, non-ideal properties of transmitter and receiver optics and cross-talk between parallel and perpendicular polarization channels can be described by a single parameter, which is essentially the overall system depolarization.

Nitric oxide provokes tumor necrosis factor-alpha expression in adult feline myocardium through a cGMP-dependent pathway

BACKGROUND

The mechanism(s) responsible for the persistent coexpression of tumor necrosis factor-alpha (TNF-alpha) and nitric oxide (NO) in the failing heart is unknown.

METHODS AND RESULTS

To determine whether NO was sufficient to provoke TNF-alpha biosynthesis, we examined the effects of an NO donor, S-nitroso-N-acetyl penicillamine (SNAP), in buffer-perfused Langendorff hearts. SNAP (1 micromol/L) treatment resulted in a time- and dose-dependent increase in myocardial TNF-alpha mRNA and protein biosynthesis in adult cat hearts. The effects of SNAP were completely abrogated by a NO quenching agent, 2-(4-carboxyphenyl)-4, 4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (C-PTIO), and mimicked by sodium nitroprusside. Electrophoretic mobility shift assays demonstrated that SNAP treatment led to the rapid induction of nuclear factor kappa-beta (NF-kappaB) but not AP-1. The importance of the cGMP pathway in terms of mediating NO-induced TNF-alpha biosynthesis was shown by studies that demonstrated that 8-bromo-cGMP mimicked the effects of SNAP and that the effects of SNAP could be completely abrogated using a cGMP antagonist, 1H-(1,2, 4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ), or protein kinase G antagonist (Rp-8-Br-cGMPS). SNAP and 8-Br-cGMP were both sufficient to lead to the site-specific phosphorylation (serine 32) and degradation of IkappaBalpha in isolated cardiac myocytes. Finally, protein kinase G was sufficient to directly phosphorylate IkappaBalpha on serine 32, a critical step in the activation of NF-kappaB.

CONCLUSIONS

These studies show that NO provokes TNF-alpha biosynthesis through a cGMP-dependent pathway, which suggests that the coincident expression of TNF-alpha and NO may foster self-sustaining positive autocrine/paracrine feedback inflammatory circuits within the failing heart.

Cytokines as emerging targets in the treatment of heart failure

Recent studies have identified the importance of biologically active molecules such as neurohormones in disease progression in heart failure. More recently it has become apparent that in addition to neurohormones another portfolio of biologically active molecules termed cytokines are also expressed in the setting of heart failure. This article reviews recent clinical and experimental material which suggest that the cytokines such as tumor necrosis factor (TNF), interleukin-1 (IL-1) and interleukin-6 (IL-6) may represent another class of biologically active molecules that are responsible for the development and progression of heart failure. In addition, we also review the early results from clinical trials that have utilized various targeted anti-cytokine strategies in patients with heart failure.

Endogenous tumor necrosis factor protects the adult cardiac myocyte against ischemic-induced apoptosis in a murine model of acute myocardial infarction

Previous studies have shown that proinflammatory cytokines, such as tumor necrosis factor (TNF), are expressed after acute hemodynamic overloading and myocardial ischemia/infarction. To define the role of TNF in the setting of ischemia/infarction, we performed a series of acute coronary artery occlusions in mice lacking one or both TNF receptors. Left ventricular infarct size was assessed at 24 h after acute coronary occlusion by triphenyltetrazolium chloride (TTC) staining in wild-type (both TNF receptors present) and mice lacking either the type 1 (TNFR1), type 2 (TNFR2), or both TNF receptors (TNFR1/TNFR2). Left ventricular infarct size as assessed by TTC staining was significantly greater (P < 0.005) in the TNFR1/TNFR2-deficient mice (77.2% +/- 15.3%) when compared with either wild-type mice (46.8% +/- 19.4%) or TNFR1-deficient (47.9% +/- 10.6%) or TNFR2-deficient (41.6% +/- 16.5%) mice. Examination of the extent of necrosis in wild-type and TNFR1/TNFR2-deficient mice by anti-myosin Ab staining demonstrated no significant difference between groups; however, the peak frequency and extent of apoptosis were accelerated in the TNFR1/TNFR2-deficient mice when compared with the wild-type mice. The increase in apoptosis in the TNFR1/TNFR2-deficient mice did not appear to be secondary to a selective up-regulation of the Fas ligand/receptor system in these mice. These data suggest that TNF signaling gives rise to one or more cytoprotective signals that prevent and/or delay the development of cardiac myocyte apoptosis after acute ischemic injury.

A chronic mouse model of myocardial ischemia-reperfusion: essential in cytokine studies

Reperfusion of the ischemic myocardium is associated with a cytokine cascade that reflects a cellular response to injury. We studied this cascade in the mouse and found that acute surgical trauma in sham-operated animals obscured early changes in cytokine induction that occur during myocardial ischemia-reperfusion (MI/R). Therefore, we utilized a new implantable device that allows occlusion and reperfusion of the left anterior descending coronary artery in a closed-chest mouse at any time after instrumentation. Induction of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha mRNA in the whole heart was examined by RNase protection assay and quantitated by Phosphor- Imager. At 3 h after instrumentation, levels of IL-6 mRNA in sham-operated animals increased above those of control naive hearts, whereas this increase did not occur until after 1 day for TNF-alpha mRNA. The surgical trauma led to exaggeration of I/R cytokine induction with greater variance in response. At 3 days and 1 wk after instrumentation, levels of both IL-6 and TNF-alpha mRNA in sham-operated animals were comparable to those of naive hearts and induction responses in I/R were much less variant. We also found that 1 h of ischemia and 2 h of reperfusion at all time points of recovery (i.e., 3 h and 1, 3, and 7 days after instrumentation) led to a significant increase in IL-6 and TNF-alpha mRNA levels. In addition, 3 h of permanent occlusion, which did not induce any mRNA increase after 1 wk postinstrumentation, caused marked upregulation of IL-6 mRNA in an acutely prepared animal. This study of early cytokine responses evoked by MI/R highlights the need for dissipation of acute surgical trauma by using a chronic, closed-chest mouse preparation.

Cytokines in heart failure: pathogenetic mechanisms and potential treatment

Recent studies have shown that patients with heart failure overexpress a class of biologically active molecules, generically referred to as pro-inflammatory cytokines. This article will review recent clinical and experimental material that suggests that pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), and interleukin-6 (IL-6) may play a role in the pathogenesis of congestive heart failure. In addition, we will review recent studies that suggest that antagonizing cytokines may represent a novel target for heart failure therapy.

An object-oriented software for fate and exposure assessments

The model system CemoS(1) (Chemical Exposure Model System) was developed for the exposure prediction of hazardous chemicals released to the environment. Eight different models were implemented involving chemicals fate simulation in air, water, soil and plants after continuous or single emissions from point and diffuse sources. Scenario studies are supported by a substance and an environmental data base. All input data are checked on their plausibility. Substance and environmental process estimation functions facilitate generic model calculations. CemoS is implemented in a modular structure using object-oriented programming.

M or M-like protein gene polymorphisms in human group G streptococci

Many group G streptococci (GGS) isolated from infected humans (but not from animal sources) express M or M-like proteins with biological, immunochemical, and genetic features similar to those of group A streptococci (GAS). To further elucidate the recently proposed M-like protein gene (emmL gene) polymorphisms in GGS, Southern blots of genomic DNAs from 38 epidemiologically unrelated GGS strains isolated from human specimens and 12 GGS strains recovered from animal sources were hybridized with oligonucleotide probes designed to specifically detect GAS M class I and M class II M protein (emm) genes. All human-associated GGS strains showed DNA homology to the GAS M class I emm gene probe, whereas no hybridization was found with DNA from any of the animal-associated strains. The emmL genes from all human isolates were amplified by PCR, and the complete sequence of the emmL gene of the Rebecca Lancefield grouping strain D166B was determined. Again, this gene exhibited the structural features typical for emm genes of M class I GAS. The 5' regions of the PCR-amplified emmL genes of the remaining 37 human GGS strains were sequenced. This region showed a sequence diversity similar to that known for GAS emm genes. When strains whose N-terminal emmL gene sequences showed a homology of > 95% were defined as belonging to one genetic type, 30 strains were segregated into six distinct genetic types, whereas the remaining 8 strains each exhibited a unique emmL gene sequence. A high degree of homology between the N-terminal emmL gene segments of six GGS strains and the corresponding regions of either the emm12 or the emm57 gene of GAS was found, suggesting a horizontal gene transfer between strains of these species of beta-hemolytic streptococci. Besides a further understanding of the evolution of GGS emmL genes, the observed emmL gene polymorphisms in GGS could provide the basis for a molecular subspecies delineation of strains and offers the potential of typing GGS for epidemiological purposes.

Rapid typing of group A streptococci by the use of DNA amplification and non-radioactive allele-specific oligonucleotide probes

Because of the allelic variations within the M protein gene (emm gene) of group A streptococci, reliable typing of this important human pathogen can be accomplished by the use of emm gene-specific oligonucleotide probes. Two technical modifications (a reverse dot blot and a reverse line blot hybridization assay) of a novel approach for the type-specific identification of emm genes have been developed. Both procedures involved amplification of an emm gene by polymerase chain reaction. The non-radioactively labeled amplicon was subsequently hybridized to a membrane carrying an array of immobilized emm gene-specific oligonucleotide probes, thus allowing the simultaneous analysis of the gene polymorphism in a single hybridization reaction. The feasibility of these rapid and easy to perform methods was shown for the unequivocal identification of reference strains and clinical isolates belonging to 16 different M serotypes.