Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Blood Specimen Collection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2000

Carbon monoxide stability in stored postmortem blood samples.

Carbon monoxide (CO) poisoning remains a common cause of both suicidal and accidental deaths in the United States. As a consequence, determination of the percent carboxyhemoglobin (%COHb) level in postmortem blood is a common analysis performed in toxicology laboratories. The blood specimens analyzed are generally preserved with either EDTA or sodium fluoride. Potentially problematic scenarios that may arise in conjunction with CO analysis are a first analysis or a reanalysis requested months or years after the initial toxicology testing is completed; both raise the issue of the stability of carboxyhemoglobin in stored postmortem blood specimens. A study was conducted at the Bexar County Medical Examiner's Office to evaluate the stability of CO in blood samples collected in red-, gray-, and purple-top tubes by comparing results obtained at the time of the autopsy and after two years of storage at 3 degrees C using either an IL 282 or 682 CO-Oximeter. The results from this study suggest that carboxyhemoglobin is stable in blood specimens collected in vacutainer tubes, with or without preservative, and stored refrigerated for up to two years.

Carbon Monoxide↗
PubMed1999

Comparative flow cytometric study of clonal excess in leukaemic peripheral blood from patients suffering from chronic lymphocytic leukaemia (B-CLL) by different antibodies, staining techniques and the effects of blood storage.

This investigation studied the effects of cell preparation methods, different antibody panels and blood storage on antigen expression of abnormal B lymphocytes from patients with B-CLL. Blood specimens collected in Heparin de novo were processed by using conventional Hypaque-Ficoll density gradient centrifugation and whole blood lysis. These were stored for 3 days at 4 degrees C, 24 degrees C and 30 degrees C. Although clonal excess was detected by all antibody panels, significant differences could be observed in terms of molecules of equivalent fluorochromes (MEF/MESF units). Evaluation of 'weak and strong' staining is dependent on the antibody panel used. Immunofluorescent values for CD19 and CD45 were unchanged at 4 degrees C and 24 degrees C but immunoglobulin staining showed best results when blood was stored at 4 degrees C. Storage at 30 degrees C produced unreliable results. Abnormal B lymphocytes should be analysed immediately after the specimen is obtained. If shipment is necessary they should be kept at 4 degrees C. Surface immunoglobulins are the 'antigens' most sensitive to storage alterations. Sample alterations alone are sufficient to the correct classification of NHL, especially in the case of low-grade NHL.

Aged↗
PubMed2005

Short-term venous stasis influences routine coagulation testing.

Preanalytical variability is a common source of errors in coagulation testing, as clotting assays are particularly susceptible to poor standardization of the whole analytical process. To investigate the effect of a short-term venous stasis on routine coagulation testing, we measured activated partial thromboplastin time, prothrombin time, fibrinogen and D-dimer in plasma specimens collected either without venous stasis or following the application of a 60 mmHg constant, standardized external pressure by a sphygmomanometer, for 1 (1-min stasis) and 3 min (3-min stasis). When compared with blood specimens collected without stasis, the Pearson's correlation coefficients and the corresponding slopes of the Passing and Bablok regression line of samples collected following 1 and 3-min stasis were acceptable. However, statistically significant differences by paired Student's t-test could be observed for all parameters tests following 3-min stasis, and for all but the activated partial thromboplastin time after 1-min stasis. Significant difference between specimens collected after 1- and 3-min stasis was also achieved for prothrombin time (P < 0.01), fibrinogen (P < 0.01) and D-dimer (P < 0.05). The agreement between measurements was yet acceptable after 1-min stasis, but achieved clinical significance for prothrombin time, fibrinogen and D-dimer after 3-min stasis. Taken together, results of the present investigation confirm that the effects of venous stasis during venipuncture are clinically meaningful. As hematocrit values and activities of clotting factors VII, VIII and XII significantly increased, whereas that of activated factor VII remained unchanged, we hypothesize that a short-term venous stasis, as induced by up to 3-min tourniquet placing, might not be sufficient to produce additional procoagulant responses besides hemoconcentration.

Blood Coagulation Factors↗
PubMed1998

A special fluorescent in situ hybridization technique to study peripheral blood and assess the effectiveness of interferon therapy in chronic myeloid leukemia.

Using a highly sensitive fluorescence in situ hybridization method with probes for BCR and ABL1 (D-FISH), we studied 37 paired sets of bone marrow and blood specimens, collected within 24 to 96 hours of each other, from 10 patients before and during treatment for chronic myeloid leukemia (CML). The normal range for 500 interphase nuclei was </=4 (</=0.8%) nuclei based on 10 bone marrow and 10 blood specimens from normal individuals. The percentage of neoplastic nuclei was usually lower in blood than bone marrow. However, changes in the percentage of neoplastic nuclei in blood and bone marrow tracked closely over the course of therapy and with the results of quantitative cytogenetic studies on bone marrow. This result indicates that D-FISH is useful to test blood from patients with CML to monitor therapy. Moreover, by analysis of 6,000 nuclei with D-FISH, residual disease was identified in bone marrow and blood for patients in complete cytogenetic remission. Consequently, D-FISH analyses of interphase nuclei from blood could substitute for Q-cytogenetic studies on bone marrow. Thus, it may not be necessary to collect bone marrow samples so frequently to monitor therapy in CML.

Antimetabolites, Antineoplastic↗
PubMed1996

Specific amplification of Ehrlichia platys DNA from blood specimens by two-step PCR.

A two-step PCR method for diagnosis of canine infectious cyclic thrombocytopenia was established. Three primers derived from the 16S and rRNA gene sequence were used to amplify genomic DNA specifically from Ehrlichia platys. Two-round amplification with DNA templates prepared from E. platys-infected blood specimens produced 742- and 385-bp fragments, but these products were not found when an Ehrlichia canis-infected blood sample and Escherichia coli were used. This method, for which the minimum detectable copy number in the blood specimen was estimated to be five ehrlichia inclusion within platelets, is more sensitive than single PCR amplification. These results demonstrate that this two-step PCR is highly sensitive and efficient for detecting the etiologic agent of canine infectious cyclic thrombocytopenia in blood. The same technique was applied to blood specimens collected from a dog inoculated with E. platys. Amplification of the target DNA fragments was observed with blood collected on the fifth day after inoculation, which indicates that this method is also feasible for early diagnosis of E. platys infection.

Animals↗
PubMed1997

HIV infection in psychiatric patients: an unlinked anonymous study.

BACKGROUND: Recent surveys suggest that psychiatric patients are at increased risk of being infected with HIV, although very little information is available concerning the seroprevalence of HIV infection among this population outside the US. The aim of this study is to determine the seroprevalence of HIV-I among patients admitted to a psychiatric in-patient unit and to gather linked anonymous risk-factor information. METHOD: An unlinked serosurvey was made, using HIV-1 antibody testing of remnant blood specimens collected for routine medical purposes, of patients consecutively admitted to an acute psychiatric unit in Madrid. RESULTS: Blood was obtained from 390 of the 477 eligible patients (81.8%). The prevalence of HIV was 5.1% (20/390). Patients aged between 18 and 39 accounted for 63.4% of the admissions and 75% of the positive results. Of the 29 patients who presented with injecting drug use, 14 were HIV-infected (48.3%; 95% CI 29.4 67.5). Of the 51 patients for whom any risk behaviour was noted on the admission chart, 18 were HIV-infected (35.3%; 95% CI 22.4 49.9). CONCLUSIONS: This study demonstrates that there is a substantial prevalence of HIV infection in psychiatric patients admitted to an acute in-patient unit. History of injecting drug use was strongly associated with seropositivity. Clinicians recognised risk factors for HIV infection in the majority of the HIV-infected cases.

Acute Disease↗
PubMed1993

The prevalence of drugs and alcohol in fatally injured truck drivers.

To assess the impact of alcohol and other drug use in the trucking industry, the National Transportation Safety Board, in collaboration with The National Institute on Drug Abuse investigated fatal-to-the-driver trucking accidents in eight states over a one year period. Comprehensive drug screens were performed on blood specimens collected from 168 fatally injured drivers. One or more drugs were detected in 67% of the drivers and 33% of the drivers had detectable blood concentrations of psychoactive drugs or alcohol. The most prevalent drugs were cannabinoids and ethanol, each found in 13% of the drivers. Cocaine or benzoylecgonine was found in 8% of the cases. Seven percent of the driver's blood specimens contained amphetamine or methamphetamine and 7% contained phenylpropanolamine, ephedrine, or pseudoephedrine. A panel of toxicologists reviewed the accident investigation report and the toxicology findings for each case and determined that impairment due to marijuana use was a factor in all cases where the delta-9-tetrahydrocannabinol concentration exceeded 1.0 ng/mL and that alcohol impairment contributed to all accidents where the blood alcohol concentration was 0.04% wt/vol or greater. In 50 of 56 cases where psychoactive drugs or alcohol were found, impairment due to substance use contributed to the fatal accident.

Accidents, Traffic↗
PubMed2002

Cholinergic toxic syndrome by the anticancer drug irinotecan: acetylcholinesterase does not play a major role.

BACKGROUND: The anticancer drug irinotecan induces cholinergic side effects that are currently ascribed to the blockade of acetylcholinesterase. This study investigated (1) the pattern of acetylcholinesterase activity in patients receiving treatment with irinotecan and (2) the relationship between acetylcholinesterase activity and plasma concentrations of irinotecan, 7-ethyl-10-hydroxycamptothecin (SN-38), and SN-38 glucuronide (SN-38G). METHODS: Twenty-five patients with advanced colorectal cancer were treated with 250 mg/m(2) irinotecan administered by intravenous infusion for 60 minutes. Blood samples were collected before drug infusion and at 15 minutes and 45 minutes after the start of drug infusion. Blood acetylcholinesterase activity was determined by a colorimetric enzymatic assay, and irinotecan, SN-38, and SN-38G concentrations were determined in plasma by HPLC. The in vitro effects of irinotecan and other drugs on human acetylcholinesterase were also assessed. RESULTS: Compared with basal values, the activity of acetylcholinesterase in blood specimens collected during irinotecan infusion at 15 minutes (-0.76%) and at 45 minutes (-1.50%) showed no changes. No relationships were established between the activity of blood acetylcholinesterase at 15 or 45 minutes and plasma concentrations of irinotecan, SN-38, or SN-38G measured at the same time points. In vitro, the activity of acetylcholinesterase was inhibited by 100-micromol/L irinotecan (-24.8%) and markedly reduced by 1-micromol/L physostigmine (-86.7%), whereas neither SN-38 nor camptothecin had an effect. CONCLUSIONS: Although the use of erythrocyte acetylcholinesterase as a surrogate marker of acetylcholinesterase activity in the nervous system has not been firmly established, our findings do not support the hypothesis that the toxic cholinergic syndrome associated with irinotecan treatment depends on acetylcholinesterase blockade.

Acetylcholinesterase↗
PubMed1994

Effects of volume and periodicity on blood cultures.

Blood specimens collected for culture by using the high-volume resin-based BACTEC system over an 18-month period at the Seattle Veterans Administration Center were examined in this study. Of 7,783 cultures obtained, 624 were classified as true positives. Patients in this group had between 20 and 60 ml of blood drawn per culture and separated into 10-ml aliquots for incubation. Analysis of the results stratified by cultured volume and time interval between specimen collection accorded yield advantage to culture volume at the maximal amounts tested. No advantage was observed with any particular interval of collection. Increasing cultured volume from 20 to 40 ml increased yield by 19%. Increasing cultured volume from 40 to 60 ml increased yield by an additional 10%. The same effect was seen whether cultures were drawn simultaneously or serially within 24 h. These observations support other reports demonstrating increased yield with increased cultured blood volume. However, they demonstrate increases in yield at volumes much higher than previously considered. In conclusion, this study demonstrates that high-volume blood cultures drawn serially or simultaneously return the best yields.

Bacteremia↗
PubMed2003

[Prevalence of Bancroftian filariasis in seven villages of the Bonassama Health District in the Wouri Estuary, littoral province of Cameroon].

Lymphatic filariasis is one of the 6 diseases targeted for global eradication by the World Health Organization. In 2000 Cameroon was selected for inclusion in the eradication program. As a prerequisite for the program, epidemiological mapping was undertaken to determine the prevalence of Wuchereria bancrofti in 7 villages located in the mangrove area of the Wouri estuary littoral province of Cameroon. Informed consent was obtained from each participant or from parents of minors. Night blood specimens were collected for thick and thin blood films, stained using the Giemsa solution, and microscopically examined to identify microfilariae of W. bancrofti. The study population included 924 subjects (336 males and 558 females). Their age ranged from 1 to 79 years (mean, 26.9 years). W. bancrofti was identified in 4 of the 7 villages with prevalence rates ranging from 0.7% to 3.25% (mean, 0.97%). All positive subjects were over 30 years old. Despite night blood specimen collection, other blood microfilariae were detected including Loa loa in 54 cases (prevalence, 5.84%) and Dipetalonema perstans in 10 (prevalence, 1.1%). Only a small number of subjects presented clinical manifestations of lymphatic filariasis (e.g., pruritus). Elephantiasis of the lower limb was identified in only one subject but there was hearsay evidence of other cases involving subjects embarrassed to come forward.

Adolescent↗
PubMed1984

Temporal stability of blood lead concentrations in adults exposed only to environmental lead.

The temporal stability of blood lead concentrations of 21 healthy adults (14 men and 7 women) exposed only to environmental lead was assessed by analysis of 253 blood specimens collected serially over periods from 7 to 11 months. Improved analytical sensitivity allowed detection of small (less than 1.0 microgram/100 ml) changes in blood lead concentrations and both within- and between-run analytical errors were minimized by a strict internal quality control protocol. The women had lower blood lead concentrations (mean 8.5, range 7.4-10.8 micrograms/100 ml) than did the men (mean 12.2, range 8.6-15.8 micrograms/100 ml). These are within the expected ranges for non-occupationally exposed persons. Blood lead concentrations in the serial specimens from both men and women changed very little over the study period, with standard deviations of less than 0.5 micrograms/100 ml for the majority of individual mean concentrations: for all except two subjects the standard deviations were less than 0.8 micrograms/100 ml. Two subjects showed significant changes in blood lead concentrations during the study (standard deviations of mean greater than 1.0 micrograms/100 ml). A temporary increase in oral lead intake was identified for one of these subjects. In the absence of substantial changes in lead exposure blood lead levels in adults are remarkably stable and for their environmental monitoring a single blood lead concentration is an excellent biological indicator.

Adult↗
PubMed2002

[Analysis of factors influencing the cord blood sample collection for clinical purposes].

The survival rate of patients after cord blood transplantation depends on the number of nucleated cell transplants. The number of nucleated cells available for transplantation closely correlates with collected volume of cord blood. The influence of several obstetric factors on the volume of cord blood donation was investigated. Cord blood was obtained from 32 normal full-term deliveries. Length of gestation, age of mother, weight of placenta and length of umbilical cord were analysed for their impact on the volume of cord blood. Mean volume of collected cord blood was 103 ml. We did not establish the correlation between the volume of collection and the weight of placenta (measured after blood collection), the length of gestation and the age of mothers. A close and significant correlation (p < 0.05, r = 0.78) concerned the length of umbilical cord and the volume of cord blood donation. Length of umbilical cord is the parameter which may be useful for selection of the most promising cases in the collection of cord blood.

Adult↗
PubMed1997

A comparison between continuous infusion versus standard bolus administration of heparin based on monitoring in cardiac surgery.

This study was designed to determine prospectively if stable heparin concentrations can be maintained during extracorporeal circulation by using a continuous infusion technique, compared with a bolus regimen based on whole blood heparin concentration monitoring. Forty patients were assigned randomly to either an infusion or a monitoring group. The reference heparin concentration was defined as the whole blood heparin concentration associated with a kaolin activated clotting time (ACT) of approximately 480 s prior to institution of cardiopulmonary bypass (CPB) for both cohorts. For infusion patients, doses of heparin were administered using a continuous infusion based on the initial patient-specific heparin dose per unit weight; heparin was also added to solutions administered after the initiation of CPB based on the reference heparin concentration. For monitoring patients, the dose of heparin administered during CPB was calculated by the Hepcon instrument. Blood specimens collected prior to and during the CPB period were used to measure anti-Xa plasma heparin concentration and complete blood counts, kaolin ACT and whole blood heparin concentration. Doses of heparin and protamine administered and transfusion requirements were similar in patient cohorts. The apparent rate of clearance of heparin from plasma was variable among patients in the monitoring group prior to CPB. Stable heparin concentrations were maintained using whole blood heparin measurements, whereas mean heparin concentrations were slightly lower using the continuous infusion technique. Therefore, an optimal approach might involve the combined use of these regimens.

Aged↗