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1.
Musculoskelet Surg ; 105(2): 149-153, 2021 Aug.
Article in English | MEDLINE | ID: mdl-31691179

ABSTRACT

PURPOSE: This study compares the clinical results of the Whipple, empty-can, and full-can tests to detect supraspinatus tendon tears. We determined the sensitivities, specificities, and positive and negative predictive values of each test with respect to the intraoperative supraspinatus tendon lesion confirmation. METHODS: We examined 61 patients (26 women, 35 men) presenting for arthroscopic surgery with functional disability or persisting shoulder pain. All the patients underwent Whipple, empty-can, and full-can testing. We correlated the clinical results of the tests with the confirmation of a supraspinatus tendon lesion by direct arthroscopic visualization. RESULTS: We examined 34 right and 27 left shoulders. For full and partial supraspinatus tendon tears, the Whipple test showed a sensitivity of 88.6% and a specificity of 29.4%, whereas the empty-can test and the full-can test had sensitivities of 88.6% and 75.0%, and specificities of 58.8% and 47.1%, respectively. CONCLUSIONS: Compared with the empty-can test and the full-can test, the Whipple test was less specific, while its sensitivity was equal to that of the empty-can test and higher than that for the full-can test. Because of its low specificity, the Whipple test has a high risk of false-positive results in comparison with the other tests.


Subject(s)
Rotator Cuff Injuries , Tendon Injuries , Arthroscopy , Female , Humans , Magnetic Resonance Imaging , Male , Prospective Studies , Rotator Cuff , Rotator Cuff Injuries/diagnostic imaging , Rotator Cuff Injuries/surgery , Tendon Injuries/diagnosis , Tendon Injuries/surgery , Tendons
2.
Sensors (Basel) ; 20(6)2020 Mar 17.
Article in English | MEDLINE | ID: mdl-32192135

ABSTRACT

Vu Gia-Thu Bon (VGTB) river basin is an area where flash flood and heavy flood events occur frequently, negatively impacting the local community and socio-economic development of Quang Nam Province. In recent years, structural and non-structural solutions have been implemented to mitigate damages due to floods. However, under the impact of climate change, natural disasters continue to happen unpredictably day by day. It is, therefore, necessary to develop a spatial decision support system for real-time flood warnings in the VGTB river basin, which will support in ensuring the area's socio-economic development. The main purpose of this study is to develop an online flood warning system in real-time based on Internet-of-Things (IoT) technologies, GIS, telecommunications, and modeling (Soil and Water Assessment Tool (SWAT) and Hydrologic Engineering Center's River Analysis System (HEC-RAS)) in order to support the local community in the vulnerable downstream areas in the event of heavy rainfall upstream. The structure of the designed system consists of these following components: (1) real-time hydro-meteorological monitoring network, (2) IoT communication infrastructure (Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), wireless networks), (3) database management system (bio-physical, socio-economic, hydro-meteorological, and inundation), (4) simulating and predicting model (SWAT, HEC-RAS), (5) automated simulating and predicting module, (6) flood warning module via short message service (SMS), (7) WebGIS, application for providing and managing hydro-meteorological and inundation data, and (8) users (citizens and government officers). The entire operating processes of the flood warning system (i.e., hydro-meteorological data collecting, transferring, updating, processing, running SWAT and HEC-RAS, visualizing) are automated. A complete flood warning system for the VGTB river basin has been developed as an outcome of this study, which enables the prediction of flood events 5 h in advance and with high accuracy of 80%.

3.
Sci Rep ; 10(1): 2619, 2020 02 14.
Article in English | MEDLINE | ID: mdl-32060342

ABSTRACT

We observed an increase in methicillin-susceptible Staphylococcus aureus (MSSA) infections at a Dutch neonatal intensive care unit. Weekly neonatal MSSA carriage surveillance and cross-sectional screenings of health care workers (HCWs) were available for outbreak tracing. Traditional clustering of MSSA isolates by spa typing and Multiple-Locus Variable number tandem repeat Analysis (MLVA) suggested that nosocomial transmission had contributed to the infections. We investigated whether whole-genome sequencing (WGS) of MSSA surveillance would provide additional evidence for transmission. MSSA isolates from neonatal infections, carriage surveillance, and HCWs were subjected to WGS and bioinformatic analysis for identification and localization of high-quality single nucleotide polymorphisms, and in-depth analysis of subsets of isolates. By measuring the genetic diversity in background surveillance, we defined transmission-level relatedness and identified isolates that had been unjustly assigned to clusters based on MLVA, while spa typing was concordant but of insufficient resolution. Detailing particular subsets of isolates provided evidence that HCWs were involved in multiple outbreaks, yet it alleviated concerns about one particular HCW. The improved resolution and accuracy of genomic outbreak analyses substantially altered the view on outbreaks, along with apposite measures. Therefore, inclusion of the circulating background population has the potential to overcome current issues in genomic outbreak inference.


Subject(s)
Cross Infection/epidemiology , Methicillin-Resistant Staphylococcus aureus/genetics , Minisatellite Repeats , Staphylococcal Infections/epidemiology , Bacterial Typing Techniques , Cross Infection/microbiology , Cross Infection/transmission , Cross-Sectional Studies , Disease Outbreaks , Humans , Infant, Newborn , Intensive Care Units, Neonatal , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Molecular Epidemiology , Polymorphism, Single Nucleotide , Staphylococcal Infections/microbiology , Staphylococcal Infections/transmission , Whole Genome Sequencing
4.
Musculoskelet Surg ; 101(2): 173-180, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28205145

ABSTRACT

Is reverse total shoulder arthroplasty a feasible treatment option for failed shoulder arthroplasty? A retrospective study of 44 cases with special regards to stemless and stemmed primary implants. BACKGROUND: Due to humeral or glenoid bone-loss and rotator cuff insufficiency reverse total shoulder arthroplasty often means the only remaining treatment option in revision shoulder arthroplasty. This study investigates the clinical outcome of patients treated with a reverse total shoulder in revision cases with special regard to stemless and stemmed primary implants. MATERIALS AND METHODS: From 2010 to 2012 60 failed shoulder arthroplasties were converted to reverse total shoulder arthroplasty. Forty-four patients were available for follow-up after a mean of 24 months. Patients were assessed with X-rays, Constant- and ASES Score and a questionnaire about their subjective satisfaction. RESULTS: The total number of observed complications was seven (16%). Ninety-eight percent of the patients were satisfied with their clinical result. Patients achieved a mean normalized constant score of 70.2% and a mean ASES Score of 65.3. Patients with stemless primary implants achieved a higher normalized constant score than patients with stemmed primary implants (82 vs. 61.8%; p = 0009). CONCLUSION: Reverse total shoulder arthroplasty provides satisfactory clinical results and a high patient satisfaction in revision shoulder arthroplasty. The complication rate needs to be considered and discussed with the patient prior to surgery. Presence or absence of a stem of revised shoulder arthroplasties interferes with the outcome. LEVEL OF EVIDENCE IV: (Retrospective study).


Subject(s)
Arthroplasty, Replacement, Shoulder/methods , Shoulder Prosthesis , Aged , Aged, 80 and over , Arthroplasty , Feasibility Studies , Female , Humans , Male , Prosthesis Design , Retrospective Studies , Treatment Failure
5.
J Dairy Sci ; 99(3): 1747-1754, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26805991

ABSTRACT

Sixty percent of milk consumed in China has a long shelf life (UHT), presumably because milk with a short shelf life (pasteurized) is comparatively expensive. This in contrast to Australia, where 10% of consumed milk is UHT and the price between UHT and pasteurized milk is equivalent. Whether UHT is actually more liked than pasteurized milk by Chinese consumers is unknown. However, the potential positive halo around the expensive pasteurized milk might result in Chinese consumers liking milk more when it is labeled as "short shelf-life milk." To test these hypotheses, Chinese (n=48, 20 males, 28 females, 23 ± 7.2 yr) and Australian (n=93, 11 males, 82 females, 24 ± 5.6 yr) consumers tasted and rated (9-point hedonic scale), in a randomized order, 3 × 30-mL samples of UHT milk (labeled as "long shelf-life milk," "short shelf-life milk," or "milk") and 3 × 30-mL samples of pasteurized milk (also labeled as "long shelf-life milk," "short shelf-life milk," or "milk"). Australian participants' liking of milk was not influenced by labeling. Regardless of what the label stated, they always preferred the taste of pasteurized milk over the taste of UHT milk. This was different for Chinese participants, who preferred the taste of UHT milk over the taste of pasteurized milk, but in general had a higher liking for any milk that was labeled "short shelf-life milk." Both Australian and Chinese were more positive about pasteurized than UHT milk. In conclusion, Chinese, but not Australian, consumers' liking of milk was guided by the positive expectations of pasteurized milk and the negative expectations of UHT milk. Further research is needed to investigate if the present findings can be extrapolated to a larger and more varied group of Chinese and Australian consumers.


Subject(s)
Cattle/physiology , Food Labeling , Food Preferences , Milk , Animals , Australia , China , Consumer Behavior , Female , Food Handling , Humans , Male , Pasteurization , Taste
6.
Orthopade ; 45(2): 125-9, 2016 Feb.
Article in German | MEDLINE | ID: mdl-26796791

ABSTRACT

BACKGROUND: Partial articular supraspinatus tendon avulsions (PASTA) lesions remain challenging with regard to diagnosis and treatment. DIAGNOSTICS: For the diagnosis of PASTA lesions, arthroscopic evaluation of the supraspinatus tendon is key. Preoperative imaging alone is usually not sufficient to make the treatment decision. OPERATIVE TECHNIQUE: For non-significant partial tears of less than 50 % of the tendon thickness a simple debridement is indicated. Two basic repair techniques, a transtendon repair technique and a repair after tear completion, can be distinguished. In PASTA lesions, a repair is generally preferred to debridement. RESULTS: Results in the literature do not favor one repair technique over the other. Prospective randomized trials comparing debridement with repair are lacking in the literature. From a technical standpoint tear completion and repair seem to be a bit more reproducible.


Subject(s)
Arthroscopy/methods , Debridement/methods , Rotator Cuff Injuries/diagnosis , Rotator Cuff Injuries/surgery , Rotator Cuff/surgery , Suture Techniques , Combined Modality Therapy/methods , Evidence-Based Medicine , Humans , Plastic Surgery Procedures , Treatment Outcome
9.
Orthopade ; 43(3): 244-8, 2014 Mar.
Article in German | MEDLINE | ID: mdl-24469689

ABSTRACT

BACKGROUND: Due to its growing popularity golf has now come into the focus of orthopedic sports medicine. With a wide range of age groups and playing levels, orthopedic surgeons will encounter a wide range of musculoskeletal problems which are usually the result of overuse rather than trauma. ANATOMY: The shoulder joint plays an important role in the golf swing whereby not only the muscles around the glenohumeral joint but also the scapula stabilizing muscles are extremely important for an effective golf swing. INJURY PATTERNS: Golf is strictly not considered to be an overhead sport; however, the extreme peak positions of the golf swing involve placing the shoulder joint in maximum abduction and adduction positions which can provoke impingement, lesions of the pulley system or even a special form of posterior shoulder instability. PERSPECTIVES: Even after complex shoulder operations, such as rotator cuff repair or shoulder arthroplasty, a return to the golf course at nearly the same level of play can be expected.


Subject(s)
Athletic Injuries/diagnosis , Golf/injuries , Shoulder Injuries , Adolescent , Adult , Age Factors , Athletic Injuries/physiopathology , Athletic Injuries/surgery , Cumulative Trauma Disorders/diagnosis , Cumulative Trauma Disorders/physiopathology , Cumulative Trauma Disorders/surgery , Electromyography , Humans , Leisure Activities , Middle Aged , Muscle, Skeletal/injuries , Muscle, Skeletal/physiopathology , Muscle, Skeletal/surgery , Occupational Injuries/diagnosis , Occupational Injuries/physiopathology , Occupational Injuries/surgery , Range of Motion, Articular/physiology , Risk Factors , Rotator Cuff/physiopathology , Rotator Cuff/surgery , Rotator Cuff Injuries , Shoulder/physiopathology , Young Adult
10.
Arch Orthop Trauma Surg ; 131(8): 1077-84, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21350968

ABSTRACT

INTRODUCTION: Over the last decade, proprioceptive function gained increasing attention in joint disorders such as instability of the shoulder. Common tests for evaluation of proprioception are limited by their complexity and high technical demands. Thus, they are hardly applicable during daily routine. Our hypothesis was that the simplified "laser-pointer assisted angle reproduction test" (LP-ART) presented here allows for clinically feasible assessment of proprioceptive shoulder function. METHODS: Active angle reproduction capability as an aspect of sensorimotor function was evaluated with the new method in patients with shoulder instability (n = 24) and healthy controls (n = 24). 15 patients had traumatic, 9 non-traumatic anterior instability (6 bilateral), 17 were treated surgically, 13 non-operatively. Tests were performed in flexion and abduction in different angles (55°, 90°, 125°) in randomized order. RESULTS: Angle reproduction capability was worst below shoulder level (55°) in all groups. Best results were achieved at shoulder level (90°). Healthy controls showed overall better results than patients with instability. Patients after surgical stabilization had better results in 55° and 90° abduction compared to instability patients before surgery. CONCLUSIONS: The new LP-ART presented here is a technically simple, yet effective instrument for evaluation of the proprioceptive function of the shoulder. In contrast to former test setups it is feasible in daily routine. Compared to healthy controls, patients with unstable shoulder joints show significant proprioceptive disorders that can be quantified by the LP-ART.


Subject(s)
Joint Instability/physiopathology , Lasers , Proprioception/physiology , Shoulder Joint/physiopathology , Adult , Feasibility Studies , Female , Humans , Male
11.
Appetite ; 50(2-3): 435-42, 2008.
Article in English | MEDLINE | ID: mdl-17977618

ABSTRACT

The present study investigated (1) whether consumption of a nibble-size snack, as compared to a bar-size snack, leads to more sensory specific satiety (SSS) and a lower intake; and (2) whether attention to consumption, as compared to usual consumption, leads to more SSS and a lower intake. Subjects (N=59) tested two snack foods which differed in size, nibbles and bars, in two consumption conditions. In the attention condition, the instruction to chew the food well was given. In the control condition no such instruction was given. For each of the four SSS sessions ad libitum intake was measured and SSS scores were calculated. Mean intake of the nibbles was 12% lower than of the bars in the control condition, but not in the attention condition. Although non-significantly, attention to consumption tended to reduce intake of the bars but not of the nibbles. SSS scores were slightly higher for the bars than for the nibbles. Our results suggest that a smaller food size results in a lower intake. The data do not clearly support the idea that attention to consumption decreases intake. Hypothetically consumption of small foods and attentive consumption prolong the oral sensory stimulation, which results in a lower intake.


Subject(s)
Eating/physiology , Eating/psychology , Energy Intake/physiology , Satiation/physiology , Taste/physiology , Adolescent , Adult , Attention , Cross-Over Studies , Female , Humans , Male , Middle Aged
12.
Orthopade ; 36(11): 1027-36, 2007 Nov.
Article in German | MEDLINE | ID: mdl-17962920

ABSTRACT

Shoulder arthroplasty is becoming increasingly important in orthopaedic surgery. Continuous development of the implants means that the modern endoprostheses make it possible to recreate the original anatomy with a high degree of accuracy. This is of decisive importance in the long-term restoration of physiological patterns of movement and achievement of pain relief. The modern shoulder arthroplasties allow adjustment of the important parameters: ante-/retroversion, inclination and offset to fit the individual anatomy of the proximal humerus. Fixation is the most important factor for the glenoid component; reduced bone stock can make this difficult. Cemented components are still the gold standard. For young patients surface replacement arthroplasty can be a good alternative treatment for early stages of osteoarthritis. In cuff tear arthropathy reverse prostheses can be used. Reversing the anatomical relationship between glenoid and humerus leads to medialisation and lowering of the center of rotation, which in turn leads to increased tension on the deltoid muscle. Because of the high complication rate this operation should be performed only by experienced shoulder surgeons.


Subject(s)
Equipment Failure Analysis , Joint Prosthesis , Prosthesis Design , Shoulder Joint/surgery , Biomechanical Phenomena , Humans , Prosthesis Fitting , Range of Motion, Articular/physiology , Shoulder Joint/physiopathology
13.
Food Chem Toxicol ; 44(10): 1636-50, 2006 Oct.
Article in English | MEDLINE | ID: mdl-16891049

ABSTRACT

The European Food Safety Authority (EFSA) and the World Health Organization (WHO), with the support of the International Life Sciences Institute, European Branch (ILSI Europe), organized an international conference on 16-18 November 2005 to discuss how regulatory and advisory bodies evaluate the potential risks of the presence in food of substances that are both genotoxic and carcinogenic. The objectives of the conference were to discuss the possible approaches for risk assessment of such substances, how the approaches may be interpreted and whether they meet the needs of risk managers. ALARA (as low as reasonably achievable) provides advice based solely on hazard identification and does not take into account either potency or human exposure. The use of quantitative low-dose extrapolation of dose-response data from an animal bioassay raises numerous scientific uncertainties related to the selection of mathematical models and extrapolation down to levels of human exposure. There was consensus that the margin of exposure (MOE) was the preferred approach because it is based on the available animal dose-response data, without extrapolation, and on human exposures. The MOE can be used for prioritisation of risk management actions but the conference recognised that it is difficult to interpret it in terms of health risk.


Subject(s)
Carcinogens/toxicity , Food/standards , Mutagens/toxicity , Animals , Carcinogenicity Tests , Europe , Foodborne Diseases/etiology , Foodborne Diseases/genetics , Humans , Mutagenicity Tests , Risk Assessment , World Health Organization
14.
J Bone Joint Surg Br ; 88(2): 208-12, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16434526

ABSTRACT

We describe 14 patients who underwent transfer of latissimus dorsi using a new technique through a single-incision. Their mean age was 61 years (47 to 76) and the mean follow-up was 32 months (19 to 42). The mean Constant score improved from 46.5 to 74.6 points. The mean active flexion increased from 119 degrees to 170 degrees , mean abduction from 118 degrees to 169 degrees and mean external rotation from 19 degrees to 33 degrees . The Hornblower sign remained positive in three patients (23%) as did the external rotation lag sign also in three patients (23%). No patient had a positive drop-arm sign at follow-up. No significant difference was noted between the mean pre- and postoperative acromiohumeral distance as seen on radiographs. An increased grade of osteoarthritis was found in three patients (23%). Electromyographic analysis showed activity of the transferred muscle in all patients.


Subject(s)
Rotator Cuff Injuries , Tendon Transfer/methods , Activities of Daily Living , Aged , Electromyography , Humans , Middle Aged , Osteoarthritis/diagnostic imaging , Osteoarthritis/physiopathology , Osteoarthritis/surgery , Postoperative Complications , Radiography , Range of Motion, Articular/physiology , Rotation , Rotator Cuff/physiopathology , Rotator Cuff/surgery , Rupture , Shoulder Joint/diagnostic imaging , Shoulder Joint/physiopathology
15.
Appl Environ Microbiol ; 71(6): 2848-52, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15932976

ABSTRACT

A two-phase cultivation system was developed which will enable studies of streptomycete differentiation by molecular biological and global techniques such as transcriptomics and proteomics. The system is based on a solid phase formed by glass beads corresponding to particles in soil, clay, or sand natural habitats of streptomycetes. The beads are immersed in a liquid medium that allows easy modification or replacement of nutrients and growth factors as well as radioactive labeling of proteins. Scanning electron microscopy was used to analyze morphological differentiation of streptomycetes on glass beads and two-dimensional protein electrophoresis to demonstrate the potential of the system for analyses of protein synthesis profiles during the developmental program. This system facilitates studies of differentiation including expression and post-translation modifications of streptomycetes proteins, secondary metabolite biosynthesis, and morphological development.


Subject(s)
Glass , Streptomyces/growth & development , Streptomyces/ultrastructure , Bacterial Proteins/metabolism , Bacteriological Techniques , Culture Media , Electrophoresis, Gel, Two-Dimensional , Gene Expression Regulation, Bacterial , Microscopy, Electron, Scanning , Particle Size , Proteomics , Streptomyces/metabolism
16.
J Bacteriol ; 185(24): 7291-6, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14645292

ABSTRACT

We identified adpA as an araC-like regulatory gene needed for colonial morphogenesis in Streptomyces coelicolor and showed that its activity depended on a unique TTA triplet corresponding to the leucyl-tRNA gene (bldA). These findings partially explained the dependence of aerial mycelium formation on a rare tRNA that is postulated to have developmental control functions.


Subject(s)
Bacterial Proteins/genetics , DNA-Binding Proteins/genetics , Mycelium/genetics , Streptomyces/growth & development , Streptomyces/genetics , Trans-Activators/genetics , Alleles , Bacterial Proteins/metabolism , Codon , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Bacterial , Phenotype , Promoter Regions, Genetic , Protein Biosynthesis , RNA, Bacterial , RNA, Transfer, Leu/genetics , Streptomyces/metabolism , Trans-Activators/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription, Genetic
17.
Mol Microbiol ; 46(5): 1223-38, 2002 Dec.
Article in English | MEDLINE | ID: mdl-12453210

ABSTRACT

In the multicellular bacterium Streptomyces coelicolor, functions of developmental (bald) genes are required for the biosynthesis of SapB, a hydrophobic peptidic morphogen that facilitates aerial hyphae formation. Here, we show that aerial hyphal growth and SapB biosynthesis could be activated independently from the normal developmental cascade by providing unprogrammed expression of functionally interactive genes within the ram cluster. ramC, ramS and ramR were essential for normal growth of aerial hyphae, and ramR, a response regulator gene, was a key activator of development. The ramR gene restored growth of aerial hyphae and SapB formation in all bald strains tested (albeit only weakly in the bldC mutant), many of which are characterized by physiological defects. Disruption of the ramR gene abolished SapB biosynthesis and severely delayed growth of aerial hyphae. Transcription of ramR was developmentally controlled, and RamR function in vivo depended on its putative phosphorylation site (D53). We identified and mapped RamR targets immediately upstream of the region encoding ramC and ramS, a putative operon. Overexpression of ramR in the wild-type strain increased SapB levels and caused a distinctive wrinkled surface topology. Based on these results, we propose that phenotypes of bald mutations reflect an early stage in the Streptomyces developmental programme similar to the spo0 mutations in the unicellular bacterium Bacillus subtilis, and that RamR has analogies to Spo0A, the Bacillus response regulator that integrates physiological signals before triggering endospore formation.


Subject(s)
Bacterial Proteins/metabolism , DNA-Binding Proteins , Gene Expression Regulation, Bacterial , Streptomyces/growth & development , Transcription Factors , Bacterial Proteins/genetics , Culture Media , Genes, Bacterial , Multigene Family , Mutagenesis, Site-Directed , Spores, Bacterial/physiology , Streptomyces/genetics , Streptomyces/metabolism , Streptomyces/physiology , Transcription, Genetic
18.
Genome Biol ; 3(7): REVIEWS1020, 2002 Jun 26.
Article in English | MEDLINE | ID: mdl-12184813

ABSTRACT

The world's most creative producers of natural pharmaceutical compounds are soil-dwelling bacteria classified as Streptomyces. The availability of the recently completed Streptomyces coelicolor genome sequence provides a link between the folklore of antibiotics and other bioactive compounds to underlying biochemical, molecular genetic and evolutionary principles.


Subject(s)
Genome, Bacterial , Streptomyces/genetics , Anti-Bacterial Agents/biosynthesis , Gene Expression Regulation, Bacterial , Pigments, Biological/metabolism , Streptomyces/cytology , Streptomyces/metabolism
19.
Br J Pharmacol ; 134(3): 553-62, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11588109

ABSTRACT

1. It is unknown how cardiac stimulation by Ca(2+) sensitization modulates the cardiovascular response to exercise when left ventricular (LV) function is chronically depressed following a myocardial infarction. We therefore investigated the effects of EMD 57033 at rest and during exercise and compared these to those of the mixed Ca(2+)-sensitizer/phosphodiesterase-III inhibitor pimobendan. 2. Pigs were chronically instrumented for measurement of cardiovascular performance. At the time of instrumentation, infarction was produced by coronary artery ligation (MI, n=12). Studies in MI were performed in the awake state, 2 - 3 weeks after infarction. 3. MI were characterized by a lower resting cardiac output (18%), stroke volume (30%) and LVdP/dt(max) (18%), and a doubling of LV end-diastolic pressure, compared to normal pigs (N, n=13). 4. In 11 resting MI, intravenous EMD 57033 (0.2 - 0.8 mg kg(-1) min(-1)) increased LVdP/dt(max) (57+/-5%) and stroke volume (26+/-6%) with no effect on heart rate, LV filling pressure, and myocardial O(2)-consumption, similar to N. 5. In MI, the effects of EMD 57033 (0.4 mg kg(-1) min(-1), IV) on stroke volume and LVdP/dt(max) were maintained during treadmill exercise up to 85% of maximal heart rate, while heart rate was lower compared to control exercise (all P<0.05). In contrast, the effects of EMD57033 gradually waned in N at increasing intensity of exercise. 6. Compared to N, the cardiostimulatory effects of pimobendan (20 microg kg(-1) min(-1), IV) were blunted in MI both at rest and during exercise compared to N. 7. In conclusion, the positive inotropic actions of the Ca(2+) sensitizer EMD 57033 are unmitigated in resting and exercising MI compared to N, while those of the mixed Ca(2+)-sensitizer/phosphodiesterase-III inhibitor pimobendan are blunted.


Subject(s)
Calcium/metabolism , Cardiotonic Agents/pharmacology , Exercise Test/drug effects , Myocardial Infarction/drug therapy , Quinolines/pharmacology , Thiadiazines/pharmacology , Ventricular Dysfunction, Left/drug therapy , Animals , Chronic Disease , Female , Hemodynamics/drug effects , Hemodynamics/physiology , Male , Myocardial Infarction/physiopathology , Pyridazines/pharmacology , Pyridazines/therapeutic use , Swine , Ventricular Dysfunction, Left/physiopathology
20.
Cardiovasc Res ; 51(4): 701-8, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11530103

ABSTRACT

OBJECTIVES: There is currently general agreement that adenosine is not involved in ischemic preconditioning (IP) in rat hearts. We hypothesized that the failure to show a role for adenosine is due to the use of brief preconditioning stimuli, and therefore investigated whether adenosine is involved when longer stimuli are employed and which receptor subtypes are involved. METHODS AND RESULTS: Infarct size (IS) was determined in anesthetized rats after 180 min of reperfusion (REP) following a 60-min coronary artery occlusion (CAO). IS was 69+/-2% (n=15) of the risk area in control rats and 45+/-2% (n=19; P<0.05) following IP by a single 15-min CAO. The non-selective adenosine receptor antagonist SPT, which itself had no effect on IS (74+/-1%), blunted the protection by IP (IS=57+/-2%, P<0.05) in a dose of 2 x 5 mg/kg i.v., and abolished the protection (IS=70+/-1%) at 2 x 25 mg/kg i.v. Following IP by three cycles of 3-min CAO and 3-min REP, IS was 24+/-6% (P<0.05), which was not affected by SPT in doses of 2 x 10 and 2 x 25 mg/kg i.v. The A(3) antagonist MRS-1191 (3.3 mg/kg, i.p.), which itself did not affect IS (70+/-2%), blunted the protection by IP with a 15-min CAO (IS=54+/-2%, P<0.05). When 2 x 5 mg/kg SPT (a dose selective for A(1)-receptors, as it did not affect the protection by the A(3) selective agonist IB-MECA, 51+/-3%) and MRS 1191 were combined the protection by IP was abolished (IS=67+/-2%). CONCLUSIONS: Involvement of adenosine in IP in rats depends critically on the duration of the stimulus. Thus, whereas adenosine was not involved when stimuli of 3-min duration were employed, activation of both A(1) and A(3) receptors contributed when a stimulus of 15 min was used.


Subject(s)
Adenosine/analogs & derivatives , Adenosine/physiology , Ischemic Preconditioning, Myocardial , Myocardial Infarction/prevention & control , Receptors, Purinergic/drug effects , Acetamides/pharmacology , Adenosine/pharmacology , Analysis of Variance , Animals , Cryoprotective Agents/pharmacology , Dihydropyridines/pharmacology , Histamine H1 Antagonists/pharmacology , Male , Purinergic Antagonists , Purinergic P1 Receptor Antagonists , Pyrilamine/pharmacology , Rats , Rats, Wistar , Receptors, Purinergic P1/drug effects , Theophylline/analogs & derivatives , Theophylline/pharmacology , Time Factors
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