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 415 records · Page 23Linked to original sources
PubMed2000

Chiral determination of mirtazapine in human blood plasma by high-performance liquid chromatography.

A method is described for the determination of the two enantiomers of mirtazapine in human blood plasma by high-performance liquid chromatography. Measurements were performed on drug free plasma spiked with mirtazapine and used to prepare and validate standard curves. Levels of enantiomers of mirtazapine were also measured in patients being treated for depression with racemic mirtazapine. Mirtazapine was separated from plasma by solid-phase extraction using CERTIFY columns. Chromatographic separation was achieved using a Chiralpak AD column and pre-column and compounds were detected by their absorption at 290 nm. Imipramine was used as an internal standard. The assay was validated for each analyte in the concentration range 10-100 ng/ml. The coefficient of variance was 16% and 5.5% for(+)-mirtazapine for 10 and 100 ng/ml control specimens respectively and 15% and 7.3% for mirtazapine for 10 and 100 ng/ml control specimens respectively. This assay is appropriate for use in the clinical range. The range of plasma mirtazapine concentrations from eleven patients taking daily doses of 30-45 mg of racemate was <5 to 69 ng/ml for (+)-mirtazapine and 13-88 ng/ml for (-)-mirtazapine for blood specimens collected 10-17.5 h after taking the dose.

Antidepressive Agents↗
PubMed1996

Current good manufacturing practices for transfusion medicine.

Transfusion medicine is most tightly controlled in the US by CGMPs that are written as regulations, guidances, and quality management documents. Because the US regulatory scheme requires that each unit of human blood donated for transfusion (and other purposes) be documented from the moment of donor registration until the last component of that donation is finally disposed of, there is precious little that remains solely within the discretion of the treating physician who orders transfusions for her or his patients. An additional complication for transfusion medicine specialists is that the search for the requirements must extend to all possible areas of information, including the possibly unexpected source within the private sector.

Blood Banks↗
PubMed1997

Significance of leukocyte concentration in the performance of the quantitative cytomegalovirus (CMV) antigenemia assay.

BACKGROUND: The quantitative cytomegalovirus-antigenemia (CMV-Ag) assay is an important technology in the regimen of tests utilized in the care and management of acquired immunodeficiency syndrome (AIDS) and other immunocompromised patient groups. Performance of this assay is contingent upon the appropriate processing of the polymorphonuclear leukocyte (PMNL) compartment of the peripheral blood. However, a cell input standard in the performance of the CMV-Ag assay, has not been established. Interpretive differences between laboratories utilizing the CMV-Ag assay may reflect this lack of test uniformity. OBJECTIVES: To determine the effect of different PMNL concentrations on the quantitation of CMV in peripheral blood. The leukocyte concentration resulting in optimal rates of viral detection, will be compared with the shell vial assay-indirect immunofluorescent assay (SVA-IFA), and conventional tube culture (TC-CPE). STUDY DESIGN: A total of 74 freshly collected blood specimens were tested by the CMV-Ag assay, using cytospin preparations consisting of 2 x 10(5), 4 x 10(5) and in preliminary experiments, 8 x 10(5) PMNLs/slide. Data obtained from these studies were compared to SVA-IFA and TC-CPE. Viral load was monitored among 11 symptomatic patients through sequential testing of these patients at the start of ganciclovir (GCV), foscarnet (PFA), or combination drug therapy. RESULTS: Among 74 blood specimens tested by the CMV-Ag assay, cytospin preparations consisting of 4 x 10(5) compared with 2 x 10(5) PMNLs/slide, affected a mean positive cell increase of 215% (P = 0.03). PMNL slide preparations consisting 8 x 10(5) cells produced background levels which prevented accurate reading of slides. The CMV-Ag assay was more sensitive than the SVA-IFA, but equivalent to TC-CPE. Among 11 patients started on drug therapy, viral load was markedly reduced in 8 within 2-3 weeks; three patients (2 deceased within 3 weeks after receiving therapy), showed no decrease in viral load. One patient was identified as harboring a PFA resistant strain. CONCLUSIONS: A PMNL concentration of 4 x 10(5) cells facilitated the reading of CMV-Ag assay slide preparations. The modified CMV-Ag assay furthermore, is applicable in the monitoring of viral load for the tracking of susceptible or resistant CMV strains.

Antigens, Viral↗
PubMed1991

Transfusion and the use of blood products.

I have reviewed areas of development in the use of blood and blood products, placing emphasis on the complications of transfusion, particularly transmission of infection. Alloimmunization in relation to transfusion of red cells and platelets has been covered and suggestions for reducing this problem assessed. The potential methods of avoiding the infective complications have been discussed including the screening of blood for infective agents, the virucidal treatment of blood products during the manufacturing process and white cell depletion. The use of recombinant DNA technology to produce coagulation factors offers the possibility of further reducing infective risks. An area of clinical promise is the use of haematopoietic growth factors to treat bone marrow failure, either congenital or acquired, such as the myelosuppressive effects of cancer chemotherapy, and reduce reliance on blood products. The aim of the chapter is to encourage the rational use of a limited resource by considering the risks inherent in transfusion and alternative strategies. In doing this it is important to audit current and future practice, and it is suggested that reference is made to the suggestions of Hume (1989) for quality assessment and assurance in paediatric transfusion medicine.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Effect of blood withdrawal and angiotensin II on prolactin release in the tilapia, Oreochromis mossambicus.

Repeated blood withdrawal (5% of estimated blood volume at 0, 1, 4, 8, 24, 48 and 76 h) from tilapia acclimated to fresh water (FW) resulted in a marked increase in plasma levels of prolactin (PRL) during the first 8 h, reaching a peak above 300 ng/ml after 4 h. The increase in plasma PRL levels was significant except for the level after 72 h. A slight but significant decrease in plasma osmolality was observed at all time points after the blood withdrawal. Repeated blood withdrawal from fish acclimated to seawater (SW) resulted in a marked increase in plasma osmolality after 4 and 8 h. A significant increase was observed in plasma growth hormone (GH) in the fish in SW until the end of the experiment, but there was no change in plasma PRL. Plasma levels of cortisol were significantly higher in the fish in SW than in those in FW during the first 24 h. Blood withdrawal resulted in a significant reduction in hematocrit values in both FW- and SW-adapted fish, suggesting hemodilution. In a separate experiment, a single blood withdrawal (20% of total blood) stimulated drinking after 5 h, regardless of whether the fish were held in FW or SW. Plasma PRL level was also elevated following a single blood withdrawal in the fish acclimated to FW, but not in the fish in SW. Intraperitoneal injection of ANG II (1.0 microg/g) into the fish in FW significantly increased plasma PRL levels after 1 h. Activation of the renin-angiotensin system after blood withdrawal and the dipsogenic action of angiotensin II (ANG II) are well established in fish. The reduction in plasma osmolality after repeated blood withdrawal in FW and the increased osmolality in SW suggest that blood volume is restored, at least in part, by drinking environmental water. These results suggest that the marked increase in PRL concentration after blood withdrawal from the fish in FW is due, at least in part, to a facilitative effect between ANG II and reduced plasma osmolality.

Acclimatization↗
PubMedDate not supplied

[Measurement of minimum disposable volume in the extraction of an analysis through an arterial catheter].

OBJECTIVE: Arterial catheters are used to extract blood samples. To maintain its permeability we use heparin solution, which may contaminate and alter the desired results. Our aim was to determine the volume of the minimum discards during blood extractions to avoid results that might be altered in the analysis of biochemistry. MATERIAL AND METHODS: A prospective study was carried out in 18 beds intensive care unit. Patients with arterial catheter (Seldicath) were included, maintaining 500 UI of heparin in saline of 500 ml, at a pressure of 300 mmHg through pressurizer (Tycos). The dead space (DS) in the radial arterial system is 0.8 ml and 1 ml in the femoral. We analyzed the reliability of different discards comparing the following: 3 ml + DS, 7.5 ml + DS, 12 ml + DS and 16.5 ml + DS. The statistical analysis was carried out through ANOVA and t Student. RESULTS: In biochemistry, significant differences were not found except for potasium (p< 0.001) with 3 ml+DS during control, although it is not clinically relevant [difference through = 0.1 mEq/l (DS 0.2)]. Significant differences in prothrombina (p = 0.004) were found in coagulation, comparing 3 ml+DS and 16.5 ml + DS and in cefaline, comparing 7.5 ml + DS (p< 0.0001) and 16.5 ml + DS. There were not significant differences in the studies of gases. CONCLUSIONS: Our study shows that to reach a reliable analytical results, it is not necessary to discard more than 3 ml+DS in biochemistry and in blood gases, and to determine cefalina time would necessary to discard a minimum of 7.5 ml+DS.

Aged↗
PubMed2001

[Regional program to improve the quality of blood transfusions in hospitals: experience of the Poitou-Charentes region].

In the Poitou-Charentes area, a regional pilot program was implemented over a two year-period to improve transfusion safety in public and private hospitals. This program consisted in: (i) an evaluation of the transfusion chain in hospitals; (ii) a regional program to guide hospitals in improving the quality process. Five workgroups were set up. Three persons in each hospital should participate in the workgroup: one representing the administration, one the medical staff and one the nursing staff. After a six months follow-up several hospitals were prompted to implement corrective and preventive measures to improve transfusion safety; (iii) a letter was regularly published to contribute to set-up a regional haemovigilance network. Such a quality improvement program revealed to be a relevant method to steer the changing blood transfusion process in hospitals.

Blood Specimen Collection↗
PubMed1987

Elimination of enoxacin in renal disease.

The elimination of enoxacin was investigated in 15 subjects, 10 of whom were hospital outpatients with renal disease and varying degrees of renal impairment. Each was given enoxacin orally (200 mg b.i.d.) for 7 days. Blood specimens collected over 24 hours after the final dose of enoxacin and urine collected during the 12-hour dose interval after the final dose were assayed for enoxacin by HPLC. The elimination half-life of enoxacin increased with worsening renal function. In general, patients with diminished renal function had lower plasma enoxacin clearance values than had normal subjects, and a statistically significant correlation between apparent oral clearance and creatinine clearance was observed. Excretion of enoxacin by the kidney accounted for 26% to 72% of the apparent plasma clearance in normal subjects. This was markedly reduced in patients with severe renal failure.

Administration, Oral↗
PubMed1999

Long-term liver function of recipients with hepatitis G virus infection after bone marrow transplantation.

To clarify the role of hepatitis G virus (HGV) infection in liver dysfunction following allogeneic BMT, we examined cryopreserved serum samples from 33 patients who had a history of blood transfusions before BMT and whose serum samples had been stored periodically, before BMT, on day 100, and thereafter for the presence of HGV-RNA and hepatitis C virus (HCV)-RNA by reverse transcription polymerase chain reaction. Nineteen patients (58%) out of 33 were positive for HGV-RNA before BMT and 10 for HCV-RNA. All patients positive for HCV-RNA were also positive for HGV-RNA. Patients were divided into three groups according to their viral status before BMT; namely, the G+C+ group (n = 10), the G+C- group (n = 9) and the G-C- group (n = 14). Two patients in the G-C- group became positive for HGV-RNA after BMT. One patient in the G+C- group suffered an acute exacerbation of hepatitis, with GPT levels reaching over 1000 IU/l, 2 and 3 years after BMT, showing quite a different clinical course from those in the G+C- group. Excluding these three patients, GPT levels of the patients in the G+C+ group were significantly higher after day 100 and remained higher than those of patients in the G+C- and G-C- groups for at least 4 years. There were no significant differences in post-transplant GPT levels between the G+C- group and the G-C- group at any time point. Of the seven patients followed-up for 5 to 10 years, three patients became HGV-RNA-negative, while four remained positive. In the absence of HCV co-infection, the behavior of GPT values post transplant in patients with HGV infection did not differ from those without HGV infection. With respect to the patient who was G+C- and showed high values of GPT 2 and 3 years post transplant, we suspect that his liver dysfunction might have been caused by some unknown virus or etiology.

Adolescent↗
PubMed2000

The use of a blood conservation pressure transducer system in critically ill patients.

We tried to determine if a blood conservation pressure transducer system reduced blood transfusions, increased haemoglobin concentration or reduced line infections in critically ill patients. One hundred patients were randomly allocated to conventional or blood conserving systems attached to systemic and pulmonary arterial catheters. Intravascular lines were cultured after removal. There were no significant differences in transfusions or haemoglobin concentration. Blood conservation: median units transfused, 2 (range 0-19); mean haemoglobin at 7 days, 11.2 g.dl-1 (SD, 1.0). Conventional: median units, 2 (range 0-34); mean haemoglobin at 7 days, 11.1 g.dl-1 (SD 1.0). Thirty-seven of 99 arterial lines were colonised in the controls compared with 29 of 96 in the blood conservation group. Patients who required haemofiltration in both groups had significantly increased transfusion requirements. Haemofiltration: median 6 units (range 0-34) vs. non-haemofiltered: median 1 (range 0-14; p < 0.001). There were no significant differences in transfusions, haemoglobin concentration or line colonisation with the blood conservation system. There is considerable potential for blood conservation during haemofiltration.

Adult↗
PubMed1999

Analysis of the polymorphism of the tumour necrosis factor (TNF) gene and promoter and of circulating TNF-alpha levels in heart-transplant patients suffering or not suffering from severe rejection.

Plasma TNF-alpha levels are generally higher in heart-graft patients who experience a rejection episode than in those who do not. Because the TNF gene and its promoter are polymorphic, we studied the relationships between genetic variability at the TNF locus, the occurrence of graft rejection and TNF-alpha plasma levels in 62 heart-transplant patients in order to investigate inter-individual differences in plasma TNF-alpha levels after allogeneic stimulation. TNF-alpha was immunoenzymatically measured in blood specimens collected on the same day as endomyocardial biopsy. After PCR amplification of DNA, NcoI and AspHI polymorphisms were characterized by their restriction profiles, TNFa microsatellites by electrophoretic separation on acrylamide and the promoter region by sequencing. Plasma levels and molecular genetic results were compared to the grade of heart graft rejection established according to pathological criteria. In our study, allograft rejection was associated neither with NcoI or AspHI polymorphism nor with nucleotide changes in the TNF-A promote. We observed low TNF-alpha levels in n1/n1 homozygous patients and in subjects with G-->A at position--308 of the promoter sequence. Concerning the polymorphism of the TNFa microsatellite, our results might suggest an association with graft rejection but we have to be very careful in drawing conclusions because of the small size of the sample.

Adult↗
PubMed1998

Evaluation of two new integrated adapters for blood drawing in closed blood bag systems: influence on different molecular coagulation markers.

We compared a conventional blood donation bag system (A) with two newly developed ones (B, C) with integrated Y-shaped adapters. The new systems facilitate the withdrawal of blood samples in a closed system under aseptic conditions. The purpose of the study was to determine whether disturbances during blood donation in the different tubings influence the quality of the donated plasma due to activation processes of the coagulation system. In all bag samples from 34 probands for each system, we found higher levels of the global tests (aPTT, TT) compared to intraindividual controls. This was due to a greater amount of anticoagulant in the bag samples. An increase of procoagulant activity was demonstrated for bags A and C. Concerning the fibrinolytic system, values were reduced in all three systems compared to controls. In summary, the quality of the plasma in the three different bag devices was comparable to controls concerning factor activities measured as global tests. The activation of the coagulation system was only slightly higher in the new system B and C than in the conventional one (A). Therefore, the new closed systems are suitable for blood donation and reveal a high coagulation quality of the plasma.

Adolescent↗
PubMed1999

Prenatal treatment of severe fetomaternal alloimmune thrombocytopenia.

Prenatal treatment of fetomaternal alloimmune thrombocytopenia (FMAIT) in previously affected families is of great clinical importance. We report here our experience in the prenatal treatment of 15 severely thrombocytopenic fetuses. Thrombocytopenia was in 13 cases due to immunization to HPA-1a, in one case to HPA-5b, and in one case to HPA-6b. Thirteen fetuses received altogether 34 intrauterine platelet transfusions, seven of them in combination with maternal-administered intravenous gammaglobulin (IVIG) and two in combination with IVIG and prednisone. Six of the 13 fetuses had only one transfusion just prior to delivery. In our experience, IVIG seemed to be less effective than reported; only two fetuses of eight treated initially with weekly maternal-administered IVIG responded, and these were the mildest affected cases in the study. On the other hand, owing to the short survival time, weekly platelet transfusions could only partly maintain a safe platelet count in the four fetuses treated with serial intrauterine platelet transfusions. The number of transfusions needed to be limited because of the high cumulative risk associated with repeated procedures. Three of 34 intrauterine platelet transfusions were associated with near-loss of three different fetuses due to prolonged fetal bradycardia after the transfusion. In conclusion, overall neonatal outcome was good, with no mortality; among the study group there was no intracranial haemorrhage (evaluated by postnatal ultrasonography) compared with one case in their untreated siblings. However, the problem of the optimal treatment of FMAIT remains to be solved. For the moment, the treatment of choice is a combination of maternal IVIG and platelet transfusions in severely affected cases. Serial fetal blood samplings (FBS) are needed in order to monitor the fetus with sufficient care.

Antigens, Human Platelet↗