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1.
Clin Toxicol (Phila) ; 52(9): 926-44, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25283255

ABSTRACT

CONTEXT: Calcium channel blocker poisoning is a common and sometimes life-threatening ingestion. OBJECTIVE: To evaluate the reported effects of treatments for calcium channel blocker poisoning. The primary outcomes of interest were mortality and hemodynamic parameters. The secondary outcomes included length of stay in hospital, length of stay in intensive care unit, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations. METHODS: Medline/Ovid, PubMed, EMBASE, Cochrane Library, TOXLINE, International pharmaceutical abstracts, Google Scholar, and the gray literature up to December 31, 2013 were searched without time restriction to identify all types of studies that examined effects of various treatments for calcium channel blocker poisoning for the outcomes of interest. The search strategy included the following Keywords: [calcium channel blockers OR calcium channel antagonist OR calcium channel blocking agent OR (amlodipine or bencyclane or bepridil or cinnarizine or felodipine or fendiline or flunarizine or gallopamil or isradipine or lidoflazine or mibefradil or nicardipine or nifedipine or nimodipine or nisoldipine or nitrendipine or prenylamine or verapamil or diltiazem)] AND [overdose OR medication errors OR poisoning OR intoxication OR toxicity OR adverse effect]. Two reviewers independently selected studies and a group of reviewers abstracted all relevant data using a pilot-tested form. A second group analyzed the risk of bias and overall quality using the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) checklist and the Thomas tool for observational studies, the Institute of Health Economics tool for Quality of Case Series, the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines, and the modified NRCNA (National Research Council for the National Academies) list for animal studies. Qualitative synthesis was used to summarize the evidence. Of 15,577 citations identified in the initial search, 216 were selected for analysis, including 117 case reports. The kappa on the quality analysis tools was greater than 0.80 for all study types. RESULTS: The only observational study in humans examined high-dose insulin and extracorporeal life support. The risk of bias across studies was high for all interventions and moderate to high for extracorporeal life support. High-dose insulin. High-dose insulin (bolus of 1 unit/kg followed by an infusion of 0.5-2.0 units/kg/h) was associated with improved hemodynamic parameters and lower mortality, at the risks of hypoglycemia and hypokalemia (low quality of evidence). Extracorporeal life support. Extracorporeal life support was associated with improved survival in patients with severe shock or cardiac arrest at the cost of limb ischemia, thrombosis, and bleeding (low quality of evidence). Calcium, dopamine, and norepinephrine. These agents improved hemodynamic parameters and survival without documented severe side effects (very low quality of evidence). 4-Aminopyridine. Use of 4-aminopyridine was associated with improved hemodynamic parameters and survival in animal studies, at the risk of seizures. Lipid emulsion therapy. Lipid emulsion was associated with improved hemodynamic parameters and survival in animal models of intravenous verapamil poisoning, but not in models of oral verapamil poisoning. Other studies. Studies on decontamination, atropine, glucagon, pacemakers, levosimendan, and plasma exchange reported variable results, and the methodologies used limit their interpretation. No trial was documented in humans poisoned with calcium channel blockers for Bay K8644, CGP 28932, digoxin, cyclodextrin, liposomes, bicarbonate, carnitine, fructose 1,6-diphosphate, PK 11195, or triiodothyronine. Case reports were only found for charcoal hemoperfusion, dialysis, intra-aortic balloon pump, Impella device and methylene blue. CONCLUSIONS: The treatment for calcium channel blocker poisoning is supported by low-quality evidence drawn from a heterogeneous and heavily biased literature. High-dose insulin and extracorporeal life support were the interventions supported by the strongest evidence, although the evidence is of low quality.


Subject(s)
Calcium Channel Blockers/poisoning , Drug Overdose/therapy , Animals , Calcium Channel Blockers/blood , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Overdose/mortality , Guidelines as Topic , Hospitalization , Humans , Insulin/therapeutic use , Length of Stay , Observational Studies as Topic , Treatment Outcome , Vasoconstrictor Agents/administration & dosage
2.
BMJ Open ; 4(4): e004699, 2014 Apr 07.
Article in English | MEDLINE | ID: mdl-24710133

ABSTRACT

INTRODUCTION: Oral corticosteroids are the cornerstone of acute asthma management in the emergency department. Recent evidence has raised doubts about the efficacy of this treatment in preschool-aged children with viral-induced wheezing and in smoking adults. The aims of the study were to: (1) document the magnitude of response to oral corticosteroids in children presenting to the emergency department with moderate or severe asthma; (2) quantify potential determinants of response to corticosteroids and (3) explore the role of gene polymorphisms associated with the responsiveness to corticosteroids. METHODS AND ANALYSIS: The design is a prospective cohort study of 1008 children aged 1-17 years meeting a strict definition of asthma and presenting with a clinical score of ≥4 on the validated Pediatric Respiratory Assessment Measure. All children will receive standardised severity-specific treatment with prednisone/prednisolone and cointerventions (salbutamol with/without ipratropium bromide). Determinants, namely viral aetiology, environmental tobacco smoke and single nucleotide polymorphism, will be objectively documented. The primary efficacy endpoint is the failure of emergency department (ED) management within 72 h of the ED visit. Secondary endpoints include other measures of asthma severity and time to recovery within 7 days of the index visit. The study has 80% power for detecting a risk difference of 7.5% associated with each determinant from a baseline risk of 21%, at an α of 0.05. ETHICS AND DISSEMINATION: Ethical approval has been obtained from all participating institutions. An impaired response to systemic steroids in certain subgroups will challenge the current standard of practice and call for the immediate search for better approaches. A potential host-environment interaction will broaden our understanding of corticosteroid responsiveness in children. Documentation of similar effectiveness of corticosteroids across determinants will provide the needed reassurance regarding current treatment recommendations. RESULTS: Results will be disseminated at international conferences and manuscripts targeted at emergency physicians, paediatricians, geneticists and respirologists. TRIAL REGISTRATION NUMBER: This study is registered at Clinicaltrials.gov (NCT02013076).


Subject(s)
Adrenal Cortex Hormones/therapeutic use , Anti-Asthmatic Agents/therapeutic use , Asthma/drug therapy , Emergency Service, Hospital , Administration, Oral , Adolescent , Asthma/complications , Asthma/genetics , Child , Child, Preschool , Clinical Protocols , Disease Progression , Eosinophilia/complications , Humans , Infant , Polymorphism, Genetic , Prospective Studies , Respiratory Tract Infections/complications , Risk Factors , Tobacco Smoke Pollution/adverse effects , Virus Diseases/complications
3.
Arch Pediatr ; 17(12): 1645-51, 2010 Dec.
Article in French | MEDLINE | ID: mdl-20951010

ABSTRACT

INTRODUCTION: Dehydration is an important complication for sick children. The Clinical Dehydration Scale for children (CDS) measures dehydration based on 4 clinical signs: general appearance, eyes, saliva, and tears. OBJECTIVE: To validate the association between the CDS and markers of dehydration in children aged 1 month to 5 years visiting emergency departments (EDs) for vomiting and/or diarrhea. METHOD: An international prospective cohort study conducted in 3 university-affiliated EDs in 2009. Participants were a convenience sample of children aged 1-60 months presenting to the ED for acute vomiting and/or diarrhea. Following triage, a research nurse obtained informed consent and evaluated dehydration using the CDS. A few days after recovery, another research assistant weighed participants at home. The primary outcome was the percentage of dehydration calculated by the difference in weight at first evaluation and after recovery. Secondary outcomes included proportion of blood test measurements, intravenous use, hospitalization, and inter-rater agreement. RESULTS: During the study period, 264 children were recruited and data regarding weight and dehydration scores were complete for 219 (83%). According to the CDS, 88 had no dehydration, 159 some dehydration, and 15 moderate or severe dehydration. A Chi-square test showed a statistical association between CDS and weight gain, the occurrence of blood tests, intravenous rehydration, hospitalization, and abnormal plasmatic bicarbonate. Good inter-rater correlation was found among participants (linear weighted Kappa score of 0.65; (95% CI, 0.43-0.87). CONCLUSION: CDS categories correlate with markers of dehydration for young children complaining of vomiting and/or diarrhea in the ED.


Subject(s)
Body Weight , Dehydration/diagnosis , Dehydration/etiology , Chi-Square Distribution , Child, Preschool , Dehydration/complications , Dehydration/therapy , Diarrhea/complications , Diarrhea/etiology , Emergency Service, Hospital , Female , Fluid Therapy , Humans , Infant , Length of Stay , Male , Physical Examination , Prospective Studies , Quebec , Reproducibility of Results , Sampling Studies , Severity of Illness Index , Switzerland , Treatment Outcome , Vomiting/complications , Vomiting/etiology , Weight Gain
4.
Electrophoresis ; 21(5): 949-55, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10768781

ABSTRACT

Streptococcus thermophilus is a lactic acid bacterium widely used for the production of fermented dairy products. The two-dimensional electrophoresis (2-DE) protein profile was obtained from three independent analyses of 2-DE gels of soluble proteins of the strain PB18. About 270 spots were detected by silver staining and the average molecular weight and isoelectric point of each protein spot were calculated to be 41 600 and 5.2, respectively. Twelve proteins were purified by chromatographic techniques because their concentration was too low for direct sequencing from blots. Eleven were located in the PB18 2-DE profile after silver staining. These preliminary results contribute to the setting up of a two-dimensional image (or reference map) of the proteins from S. thermophilus in order to identify and compare strains of various origin or to follow metabolic process such as stress. Bidimensional autoradiographs of two strains (PB18 and ST105) of S. thermophilus grown in exponential phase at 42 degrees C with [35S]methionine were compared with an image analysis system. Among the eleven located proteins in the 2-DE silver-stained profile, nine were found in PB18 and eight in ST105 autoradiographs. One protein was specific to PB18. The eight proteins could play the role of internal 2-D PAGE markers of p/ and Mr for S. thermophilus.


Subject(s)
Bacterial Proteins/analysis , Electrophoresis, Gel, Two-Dimensional , Peptide Mapping , Streptococcus/chemistry , Amino Acid Sequence , Bacterial Proteins/chemistry , Isoelectric Point , Isotope Labeling , Molecular Sequence Data , Molecular Weight , Peptide Fragments/chemistry , Sequence Analysis, Protein , Sequence Homology , Silver Staining , Solubility , Sulfur Radioisotopes
5.
J Biotechnol ; 78(2): 171-84, 2000 Mar 10.
Article in English | MEDLINE | ID: mdl-10725540

ABSTRACT

Flow cytometry was used to demonstrate the presence of beta-lactoglobulin (betaLG) receptors on living murine hybridoma MARK-3 cells using a fluorescein isothiocyanate-betaLG conjugate (FITC-betaLG: molar ratio of 5:1). A site occupation curve was produced using a shift in the mean channel fluorescence at various concentrations of FITC-betaLG. The binding of labelled ligand was concentration dependent and was inhibited by unlabelled betaLG. The on-rate constant was 3.2x10(2) M(-1) min(-1) and the off-rate constant was 0.002 min(-1). Scatchard plot analysis gave a dissociation constant (K(d)) of 44+/-21x10(-7) and 39+/-24x10(-5) M (n=3). Flow cytometry indicated that at least 15% of the FITC-betaLG were internalized for 5 min and that internalization was temperature- and time-dependent. The internalization was confirmed by 3-D fluorescence microscopy (CELLScan system).


Subject(s)
Flow Cytometry , Hybridomas/chemistry , Lactoglobulins/metabolism , Receptors, Cell Surface/analysis , Animals , Cattle , Cell Line , Fluorescein-5-isothiocyanate , Fluorescent Dyes , Mice , Receptors, Cell Surface/metabolism
6.
Curr Microbiol ; 39(6): 342-0347, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10525839

ABSTRACT

Streptococcus thermophilus is widely used in food fermentations; it commonly suffers diverse stress challenges during manufacturing. This study investigated the cold shock response of S. thermophilus when the cell culture temperature shifted from 42 degrees C to 15 degrees C or 20 degrees C. The growth of cells was affected more drastically after cold shock at 15 degrees C than at 20 degrees C. The generation time was increased by a factor of 19 when the temperature was lowered from 42 degrees to 20 degrees C, and by a factor of 72 after a cold shock at 15 degrees C. The two-dimensional electrophoretic protein patterns of S. thermophilus under cold shock conditions were compared with the reference protein pattern when cells were grown at optimal temperature. Two proteins of 21.5 and 7.5 kDa synthesized in response to cold shock were characterized. N-terminal sequencing and sequence homology searches have shown that the 7.5-kDa protein belonged to the family of the major cold shock proteins, while no homology was found for the new cold shock protein of 21.5 kDa.


Subject(s)
Bacterial Proteins/biosynthesis , Cold Temperature , Streptococcus/metabolism , Amino Acid Sequence , Bacterial Proteins/chemistry , Electrophoresis, Gel, Two-Dimensional , Molecular Sequence Data , Sequence Alignment , Streptococcus/chemistry , Streptococcus/growth & development
7.
Antimicrob Agents Chemother ; 41(7): 1468-74, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9210668

ABSTRACT

The effect of timing of gentamicin dosing relative to food access periods was evaluated in experimental animals. Female Sprague-Dawley rats were treated for 4 and 10 days with gentamicin (40 mg/kg of body weight/day) intraperitoneally at either 0700, 1300, 1900, or 0100 h according to three food presentation schedules: food was available from 0800 to 1600 h in the first group, from 1600 to 0000 h in the second group, and from 0000 to 0800 h in the last group. Animals were thus subjected to a restricted feeding period. Results indicate that time-restricted feeding schedules displace the peak and the trough of gentamicin-induced renal toxicity, as evaluated by changes in the inhibition of sphingomyelinase activity, cellular regeneration (incorporation of [3H]thymidine into DNA of renal cortex), and blood urea nitrogen and serum creatinine levels, as well as histopathological lesions observed after 10 days of treatment. In fact, the toxicity was minimal when gentamicin was injected during the feeding period, while the maximal toxicity was found when gentamicin was administered during the fasting period. It is concluded that the feeding period can modulate aminoglycoside nephrotoxicity. The time of dosing of gentamicin relative to the time of feeding seems to be a more important modulator of gentamicin nephrotoxicity than the light-dark cycle.


Subject(s)
Anti-Bacterial Agents/toxicity , Circadian Rhythm/drug effects , Food , Gentamicins/toxicity , Kidney Diseases/chemically induced , Analysis of Variance , Animals , Drug Evaluation, Preclinical , Female , Multivariate Analysis , Rats , Rats, Sprague-Dawley
8.
Crit Rev Food Sci Nutr ; 37(4): 393-410, 1997 Jun.
Article in English | MEDLINE | ID: mdl-9227891

ABSTRACT

Substantial progress has been made in our knowledge of the biological properties of mammal milks. Many nutritional, biochemical, immunological, or other biological properties have been studied in mature or industrially processed bovine milk as well as in human milk and colostrum. This article is a critical review of selected publications covering (1) the use of bovine milk or dairy byproducts (processed acid and enzymatic whey fractions) as a serum substitute for cell cultures, (2) specific factors in bovine milk and industrially processed milk the affect cell proliferation, and (3) the known functional and biological roles of two whey proteins: beta-lactoglobulin and the PP3 component.


Subject(s)
Culture Media , Dairy Products/analysis , Milk/chemistry , Animals , Cattle , Cell Division , Cells, Cultured , Humans , Milk Proteins
9.
Arthritis Rheum ; 38(9): 1211-7, 1995 Sep.
Article in English | MEDLINE | ID: mdl-7575714

ABSTRACT

OBJECTIVE: To determine the prevalence and clinical correlations of an anomaly consisting of electroencephalographic (EEG) waves within the alpha frequency band during non-rapid eye movement (NREM) sleep in patients with fibromyalgia, and to evaluate the alpha NREM sleep anomaly as a predictor of response to amitriptyline. METHODS: Twenty-two patients with fibromyalgia were studied in a 2-month, double-blind, crossover trial of amitriptyline (25 mg/day) versus placebo. Nocturnal EEGs were conducted on 2 consecutive nights at baseline and at the end of each 2-month treatment period. RESULTS: Six patients (27%) had a clinical response to amitriptyline, while none responded to placebo (P = 0.02). Treatment with amitriptyline or placebo did not result in any changes in the alpha ratings during NREM sleep. Only 8 patients (36%) exhibited the alpha NREM sleep anomaly at baseline. Those patients reported more sleep difficulty, but otherwise were clinically indistinguishable from those without this EEG sleep anomaly. Lower baseline alpha NREM sleep ratings were seen in responders to amitriptyline than in nonresponders, but these differences did not reach statistical significance. CONCLUSION: The alpha NREM sleep anomaly is present in only a small proportion of patients with fibromyalgia. It does not correlate with disease severity nor is it affected by treatment with amitriptyline. A larger sample size will be needed to adequately assess the value of this sleep anomaly in predicting the response to amitriptyline.


Subject(s)
Amitriptyline/therapeutic use , Electroencephalography , Fibromyalgia/drug therapy , Fibromyalgia/physiopathology , Sleep/physiology , Adult , Alpha Rhythm , Double-Blind Method , Electronic Data Processing , Female , Humans , Male , Middle Aged
11.
Am J Epidemiol ; 140(8): 700-10, 1994 Oct 15.
Article in English | MEDLINE | ID: mdl-7942772

ABSTRACT

This case-control study assesses relations of human papillomavirus (HPV) type 16 infection, sexual history, cigarette smoking, and oral contraceptive use to low- and high-grade cervical intraepithelial neoplasia (CIN). A total of 548 high-grade and 338 low-grade CIN cases and 612 controls were identified among women seen at a colposcopy clinic in Quebec, Quebec, Canada, in 1988-1989. Interviews, colposcopy, cervical scrapings, and colposcopically directed biopsies were performed. One pathologist reviewed all histologic slides. Southern blot techniques were used to assay specimens for HPV 16 DNA. Lifetime number of sexual partners was related to low- and high-grade CIN. Presence of HPV 16 DNA was associated with a 8.7-fold (95% confidence interval 5.1-15.0) elevation in estimated relative risk of high-grade CIN. Relative risk of high-grade CIN increased with amount of HPV 16 DNA (p < 0.0001). Estimated relative risk of high-grade CIN in current cigarette smokers was 2.4 (95% confidence interval 1.8-3.2) compared with never smokers and increased with number of pack-years of exposure (p < 0.0001). Long-term (6 years or more) users of oral contraceptives had an estimated relative risk of high-grade CIN of 1.9 (95% confidence interval 1.1-3.3) compared with those who never used such contraceptives. In contrast, presence of HPV 16 DNA, cigarette smoking, and oral contraceptive use showed little or no relation to low-grade CIN. Risk factors for low- and high-grade CIN may differ substantially.


Subject(s)
Uterine Cervical Dysplasia/epidemiology , Uterine Cervical Neoplasms/epidemiology , Adult , Case-Control Studies , Contraceptives, Oral/adverse effects , Female , Humans , Papillomaviridae/isolation & purification , Papillomavirus Infections/complications , Risk Factors , Sexual Behavior , Smoking/adverse effects , Tumor Virus Infections/complications , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/virology , Uterine Cervical Dysplasia/pathology , Uterine Cervical Dysplasia/virology
12.
J Thorac Cardiovasc Surg ; 107(2): 576-82; discussion 582-3, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8302077

ABSTRACT

Sleeve lobectomy is a lung-saving procedure indicated for central tumors for which the alternative is a pneumonectomy. The relation between survival and nodal status is controversial because, in most series, the presence of N1 disease adversely affects the prognosis with few or no long-term survivors. During the period 1972 to 1992, 142 patients underwent sleeve resection for lung cancer at our institution. Mean age (+/- standard deviation) was 60.7 +/- 9.1 years (range 11 to 78 years), and indications for operation were a central tumor in 112 patients (79%), a peripheral tumor in 18 patients (13%), and compromised pulmonary function in 12 patients (8%). Histologic type was predominantly squamous (72.5%) followed by nonsquamous (24.6%) and carcinoid tumors (2.8%). Resection was complete in 124 patients (87%) and incomplete in 18 (13%), and the operative mortality was 2.1% (n = 3). Follow-up was complete for the 139 remaining patients. Including operative deaths, survivals at 5 and 10 years for all patients were 46% (95% confidence intervals 38% to 55%) and 33% (95% confidence intervals 24% to 42%), respectively. For patients with N0 status (n = 73), 5- and 10-year survivals were 57% (95% confidence intervals 45% to 69%) and 46% (95% confidence intervals 32% to 60%); for patients with N1 status (n = 55), these rates were 46% (95% confidence intervals 32% to 60%) and 27% (95% confidence intervals 14% to 40%) (p = 0.13). No patient with N2 status (n = 14) survived 5 years. Local recurrences occurred in 23% of cases, but the prevalence was not statistically different between patients with N0 disease (16.6%) and N1 disease (23.1%) (p = 0.43). These data suggest that sleeve resection is an adequate operation for patients with resectable lung cancer and N0 N1 status. The presence of N2 disease significantly worsens the prognosis and may contraindicate the use of the procedure.


Subject(s)
Lung Neoplasms/mortality , Lung Neoplasms/surgery , Pneumonectomy/methods , Adolescent , Adult , Aged , Bronchi/surgery , Child , Contraindications , Female , Follow-Up Studies , Humans , Life Tables , Lung Neoplasms/pathology , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Recurrence, Local , Neoplasm Staging , Prognosis , Survival Rate
13.
World J Surg ; 17(6): 712-8, 1993.
Article in English | MEDLINE | ID: mdl-8109107

ABSTRACT

Sleeve lobectomy is a lung-saving procedure usually indicated for central tumors for which the alternative is a pneumonectomy. It preserves normal lung tissue and may enable pulmonary resection to be done in selected patients with inadequate cardiac or pulmonary reserve. One experience extends from January 1972 to December 1991, during which time 142 patients underwent a variety of sleeve resections for bronchogenic neoplasms. The majority of operations were upper-lobe sleeve resections (N = 110) and most procedures were considered complete and potentially curative (87%). There were three postoperative deaths (surgical mortality of 2.5%) and prolonged atelectasis was the most common major complication (N = 9). Follow-up was complete for the 139 survivors (mean follow-up time of 2,149 days) and overall survival was 46% at 5 years and 33% at 10 years. Five- and 10-year survivals for patients with stage I disease were 63% and 52%, respectively, while only 14% of patients with stage III disease survived 5 years. Local recurrences occurred in 23% of patients but when the resection had been complete, this incidence was 17% (21/124). These results indicate that sleeve resection is an adequate cancer operation for both compromised and uncompromised patients. Operative mortality, survival, and incidence of local recurrence are not different than what is seen after more conventional procedures.


Subject(s)
Carcinoma, Bronchogenic/pathology , Carcinoma, Bronchogenic/surgery , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Pneumonectomy/methods , Bronchi/surgery , Carcinoma, Bronchogenic/mortality , Humans , Lung Neoplasms/mortality , Neoplasm Staging , Survival Rate
14.
Appl Microbiol Biotechnol ; 39(2): 216-20, 1993 May.
Article in English | MEDLINE | ID: mdl-7763729

ABSTRACT

Streptococcus thermophilus strain CNRZ 455 produces a type II restriction endonuclease designated Sth455I. This enzyme was isolated from cell extracts by anionic and cationic exchange chromatography. This yielded an enzyme preparation free of non-specific nucleases. The optimal reaction conditions for Sth455I are: MgCl2, 30 mM; pH range, 8-9; incubation temperature, 37-42 degrees C; and a high NaCl concentration, 100-200 mM. The results of single- and double-digestion experiments indicates that Sth455I is an isoschizomer of BstNI and EcoRII showing different sensitivity to methylation. The enzyme exhibits restriction activity on the DNA of three bacteriophages of S. thermophilus and no activity on the phage lytic for strain CNRZ 455. The restriction/modification system associated with this strain is discussed.


Subject(s)
Bacterial Proteins/isolation & purification , DNA Restriction-Modification Enzymes , Deoxyribonucleases, Type II Site-Specific/isolation & purification , Streptococcus/genetics , Bacterial Proteins/metabolism , Base Sequence , DNA, Viral/metabolism , Deoxyribonucleases, Type II Site-Specific/metabolism , Molecular Sequence Data , Streptococcus/enzymology , Streptococcus Phages/genetics , Substrate Specificity
15.
Biorheology ; 22(5): 425-35, 1985.
Article in English | MEDLINE | ID: mdl-2937465

ABSTRACT

In order to define various aspects of platelet rheological activation, samples of whole blood and platelet-rich plasma (PRP) from the same donors were subjected for 5 min to shear rates increasing from 10 to 10000 sec-1 (shear stresses from 10(-2) to 30 Pa approximatively) in a Couette type viscometer. The following parameters were measured: erythrocyte hemolysis; lactic dehydrogenase activity; plasma B-Thromboglobulin (B-TG); adenine nucleotides, and platelet photometric aggregation. The experimental results reveal that: In whole blood, hemolysis only reached at maximum 2% of the total hemolysis. Plasma LDH activity increased regularly beyond 500 sec-1, in close correlation with B-TG plasma concentration. In contrast, ADP and ATP levels remained stable up to 1000 sec-1 then increased slowly. In PRP, the LDH, ADP and ATP levels remain practically stable up to shear rates around 5000 sec-1. In contrast, B-TG appeared to be released in plasma at shear rate values of 3000 sec-1 and its progression is only correlated with the other parameters, when the platelet lysis occurred. Finally, a rapid and complete inhibition of platelet aggregation to ADP was observed from 5000 sec-1.


Subject(s)
Blood Platelets/physiology , Adenosine Diphosphate/blood , Adenosine Triphosphate/blood , Erythrocytes/metabolism , Hemolysis , Humans , L-Lactate Dehydrogenase/blood , Platelet Aggregation , beta-Thromboglobulin/metabolism
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