[Prevalence and influencing factors of deciduous dental caries among preschool children in Qingdao city in 2019]

In 2019, the rate of primary tooth caries rate among 1 598 preschool children in Shinan District and Shibei District of Qingdao was 59.4%. The multivariate logistic regression model showed that compared with children ≤ 2 years old with history of iron deficiency anemia (IDA), suffering IDA, breastfeeding to 2 years old and no tooth melanin, children ≤ 2 years old without history of IDA, not suffering IDA, breastfeeding to less than 2 years old and heavy tooth melanin had a lower risk of primary tooth caries, with OR (95%CI) values about 0.328 (0.197-0.549), 0.354 (0.208-0.603), 0.636 (0.437-0.926) and 0.301 (0.143-0.635), respectively.

[Effect of NCCN (2015) risk stratification on prognosis of patients with acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation]

Objective: To analyze the effect of NCCN (2015) risk stratification on prognosis of patients with acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Retrospective analysis of 258 patients with AML in CR (186 cases in CR(1), 72 cases in CR(2)) who underwent allogeneic HSCT in our hospital between April 2012 and March 2015 according to NCCN (2015) risk stratification. Of them, 63 cases were classified as low risk, 112 cases intermediate risk and 83 cases high risk. Results: ①With the median follow up of 18 (5-41) months, two-year disease free surviva (DFS) in 258 patients was 78.0% (95% CI 60.4%-96.6%) . Two-year DFS in AML after transplantation was 78.6% (95% CI 61.0%-96.2%) in low risk, 76.0% (95% CI 84.0%-93.6%) in intermediate risk and 80.3% (95% CI 62.7%-97.9%) (P=0.886) in high risk groups respectively. ②Univariate analysis showed that DFS has no significant difference in patient age, the median disease course before HSCT, the WBC number at the beginning of the disease, blood routine and chromosomes examination before transplantation, extramedullary disease before transplantation, disease status before transplantation, conditioning regimen, donor type, donor and recipient sex, recipient blood type, transfused MNC number, transfused CD34(+) cell number and transfused CD3(+) cell number. DFS was significant lower in primary AML than that in secondary AML (P=0.006) and also lower in MRD positive than that in MRD negative (P=0.003) . The accumulative relapse was significant higher in CR(2) compared to that in CR(1) (P=0.046) . Accumulative non-relapse mortality (NRM) was significanlyt higher in secondary AML compared to that in primary AML (P=0.004) and also higher in MRD positive compared to that in MRD negative (P=0.010) . ③Multivariate analysis showed that MRD positive was the only significant factor in DFS and NRM. Conclusion: Allo-HSCT treatment of AML CR patients could achieve a high efficacy, which is similar between CR(1) and CR(2) patients. There is no significant correlation between NCCN (2015) risk stratification and the prognosis of AML patients with allo-HSCT treatment. Pre-conditioning MRD status monitored by multiparameter flow cytometry was the only impact factor on DFS and NRM in allo-HSCT for CR-AML patients.

[Effect of minimal residual disease monitoring by multiparameter flow cytometry pre-conditioning on prognosis of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation]

目的

分析预处理前多参数流式细胞术（MFC）监测的骨髓微小残留病（MRD）对急性髓系白血病（AML）异基因造血干细胞移植（allo-HSCT）预后的影响，探讨MFC监测MRD在AML allo-HSCT预后评估中的价值。

方法

回顾性分析2012年4月至2015年3月行allo-HSCT的186例AML患者，预处理前骨髓细胞形态学均达第1次完全缓解（CR₁）。采用8色MFC对预处理前骨髓进行MRD检测，任何水平异常均定义为MRD阳性。

结果

①186例AML患者中151例MRD阴性；35例MRD阳性，其中25例MRD<1%，10例MRD为1%~3%。②2年总体无病生存（DFS）率为80.0%（95% CI 68.5%~92.3%）。与MRD阴性组比较，MRD阳性组DFS率低[62.9%（95% CI 50.6%~75.2%）对88.9%（95%CI 76.6%~100.0%），P<0.001]、复发率高[11.4%（95%CI 4.1%~29.0%）对3.3%（95%CI 0.6%~20.9%），P=0.003]、非复发死亡率（NRM）高[25.7%（95%CI 8.1%~43.3%）对7.9%（95%CI 1.3%~26.5%），P=0.001]。继发性AML组DFS率低（P=0.004），NRM高（P=0.003）。③多因素分析结果显示预处理前MFC检测的MRD阳性是DFS[HR=4.565（95%CI 2.918~9.482），P<0.001]、复发[HR=5.854（95% CI 1.538~22.288），P=0.010]及非复发死亡[HR=3.379（95%CI 1.361~8.391），P=0.009]的独立危险因素。

结论

预处理前MFC监测的MRD阳性是影响allo-HSCT治疗CR₁-AML独立危险因素，MFC监测MRD可用于AML allo-HSCT的预后评估。

UBR5 promotes cell proliferation and inhibits apoptosis in colon cancer by destablizing P21

UBR5 is recently recognized as a key player in a large number of prevalent cancers. In this study, we sought to explore the connection of UBR5 expression with cell proliferation, apoptosis, as well as the regulation mechanism in colon cancer cell line. SiUBR5 or oeUBR5 were separately applied to interfere the expression of UBR5. Western blot, DNA gel electrophoresis and qPCR were performed to detect the expression of UBR5 at mRNA and protein level. Then MTT and flow cytometry were used to explore the proliferation and apoptosis in a colon cancer cell line in vitro. Finally, we explored the interaction and correlation of UBR5 and P21 in the colon cancer regulation. We found that UBR5 was highly expressed in colon cancer not only at mRNA level but also at protein level. Moreover, UBR5 can promote the growth of colon cancer cells, and inhibit apoptosis. The mechanism exploration proved that UBR5 can degrade P21 via ubiquitination. All these findings suggest that UBR5 may be involved in progression of colon cancer and could be a new therapeutic target for this disease.

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis.

Expression of COX-2 in stomach cancers and its relation to their biological features

BACKGROUND/AIM

Cyclooxygenase-2 (COX-2) is one of the key isoenzymes in the production of prostaglandins, and is believed to be involved in carcinogenesis. This study was conducted to examine the role of COX-2 in the development and biological behavior of stomach cancer.

METHODS

Expression of COX-2 at the mRNA and protein levels was analyzed using RT-PCR and immunoblotting assay in 50 cancerous and corresponding non-cancerous tissue specimens. Also, COX-2 expression was detected by an immunohistochemical method in 55 paraffin-embedded gastric adenocarcinoma tissues.

RESULTS

Of the 50 carcinoma tissue samples analyzed, 38 (76.0%) had overexpression of COX-2 as compared to the paired non-cancerous specimens. The overexpression of COX-2 (91.7%) was more prevalent in tumors with sizes of >5 cm than those (61.5%) of </=5 cm (p < 0.05). COX-2 overexpression was higher in tumors with >6 metastatic nodes compared to those with </=6 metastatic nodes (100.0 vs. 61.3%, p < 0.01). The rate of COX-2 overexpression in non-signet ring cell carcinoma was significantly higher compared with signet ring cell carcinoma (84.1 vs. 16.7%, p < 0.05). The rate of COX-2 overexpression (86.8 or 90.9%) in patients with a cancer invasion depth of pT3 + pT4 or with stage III + IV was significantly higher than that (41.7 or 47.1%) in patients with pT1 + pT2 or with stage I + II (both p < 0.01). Furthermore, consistent with the results at the protein and mRNA levels, immunohistochemical stain indicated that COX-2 protein was overexpressed in 39 of 55 (70.9%) carcinomas, and the 5-year survival rate (25.6%) for patients with COX-2 overexpression seemed better than that (50.0%) of patients without overexpression, though the difference was not significant (p < 0.05).

CONCLUSION

Our results indicate that COX-2 may play a role in the development of gastric cancer and its overexpression is associated with lymphatic metastasis, tumor invasion and differentiation of gastric carcinoma.

The effect of G-CSF-stimulated donor marrow on engraftment and incidence of graft-versus-host disease in allogeneic bone marrow transplantation

Graft-versus-host disease (GVHD) and infection are major obstacles to successful allogeneic bone marrow transplantation (allo-BMT). In an attempt to improve the results of HLA-identical sibling BMT, we investigated the effect of accelerating hemopoietic reconstitution and reducing acute GVHD (aGVHD) in allo-BMT receiving G-CSF-stimulated donor marrow and the preliminary biological mechanism. The donors of 30 patients (study group) with leukemia were given G-CSF 3-4 microg/kg/d for 7 doses prior to marrow harvest. The results of subsequent engraftment in the recipients were compared with those of 18 patients without G-CSF (control group). Five donors themselves were studied to assess the effects of G-CSF on the hematopoietic progenitor cells and lymphocyte subsets in the bone marrow (BM). We observed that the stimulated BM yielded higher numbers of nucleated cells as well as CFU-GM and CD34+ cells (p<0.01), and that hemopoietic reconstitution was accelerated. The median number of days of granulocyte count exceeding 0.5x10(9)/L and platelet count exceeding 20x10(9)/L was 16 (range 10-23 d) and 18.5 (range 13-31 d), respectively (control group: median 22 d, range 13-29 d and median 23 d, range 17-34 d; p=0.001). The incidence of grade II-IV severe aGVHD was very low, with only 1 case (3.3%) with acute grade II aGVHD limited to the skin in the study group. Five of 18 patients in the control group manifested grade II-IV severe aGVHD (27.8%, p=0.02). The number of T-lymphocyte subsets in the harvested BM using G-CSF stimulation was changed. In the G-CSF-stimulated marrow group, CD4+ decreased and CD8+ increased significantly (p=0.02). The changes of progenitor cells and T-lymphocyte subsets in donors' BM from pre- and post-G-CSF stimulation showed that the percentage of CD4+ reduced (p=0.04) and that of CD8+ increased (p=0.06), while that of CD34+ also increased (p=0.002). The incidence of chronic GVHD and relapse had no significant difference between both groups. These results indicate that allo-BMT in BM G-CSF priming can accelerate engraftment and minimize the incidence of severe aGVHD. There is a trend in favor of improved transplantation-related mortality.

Proinflammatory cytokines regulate myogenic cell proliferation and fusion but have no impact on myotube protein metabolism or stress protein expression

The objective of the present study was to evaluate the effect of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-alpha (IL-1a), on myoblast proliferation and fusion and on myocyte protein metabolism and stress protein expression. Proliferation was suppressed (p < 0.05) by both cytokines, alone and in combination, and at lower concentrations, the suppression was additive. Likewise, fusion was retarded (p < 0.05) by these cytokines alone and in combination. Myosin synthesis was not altered acutely or chronically by TNF-alpha alone or by the combination of this cytokine with IL-1alpha. Chronic exposure to TNF-alpha did not alter total cellular protein synthesis, but exposure to IL-1alpha and the cytokine combination resulted in an increase (14% to 19%, p < 0.05) in synthesis. Neither total cellular protein nor myosin degradation were influenced by either cytokine alone or by the combination. There was no detectable induction, acutely or chronically, of any of the stress proteins evaluated (HSC70, HSP70, or HSP60). These data suggest that cytokines may alter muscle growth and development prenatally and postnatally and that the changes in muscle protein metabolism during periods of immune challenge are not direct effects of TNF-alpha or IL-1alpha.

Porcine somatotropin improves growth in finishing pigs without altering calpain 3 (p94) or alpha-actin mRNA abundance and has a differential effect on calpastatin transcription products

The objective of this study was to determine whether the improvements in growth and efficiency of gain achieved by recombinant porcine somatotropin (pST) are associated with altered expression of the p94, calpastatin, or alpha-actin genes in porcine longissimus (LD) muscle. Forty-eight barrows (initial 64.2 to 67.4 kg BW) were assigned to four treatments (n = 12) arranged as a 2 x 2 factorial in a randomized complete block design. Factors were duration of treatment (3 or 6 wk) and pST administration (0 or 3 mg x pig(-1) x d(-1)). Plasma samples were obtained 24 h after the first pST injection and at the end of the each treatment period for assays of selected variables. The LD samples were obtained at 3 and 6 wk of pST treatment. Northern blot analysis of calpastatin expression in LD muscle revealed three distinct transcription products of approximately 8.5 (CPST I), 5.5 (CPST II), and 2.5 (CPST III) kb; CPST II was reduced (P < .02) 33 and 61% by pST at 3 and 6 wk, respectively, whereas CPST I and III were not influenced (P > .12). Neither alpha-actin nor p94 was responsive to pST injection. As expected, pST resulted in higher (50%, P < .02) plasma insulin within 24 h and one- and twofold higher (P < .01) concentrations at 3 and 6 wk, respectively. Glucose was increased (P < .01) at 3 (15%) and 6 (10%) wk, whereas urea nitrogen was reduced (32 to 36%, P < .01). The efficacy of pST was evident in that ADG was improved (P < .01) 11 to 13% independent of time. Likewise, feed intake was reduced (P < .01) 10 to 11% and gain: feed improved (P < .01) approximately 26% for pigs receiving pST independent of time. These data indicate that the enhanced muscle growth achieved by pST is not associated with altered expression of p94 or alpha-actin, or an increase in the abundance of any calpastatin transcription product.

The effect of ractopamine on beta-adrenoceptor density and affinity in porcine adipose and skeletal muscle tissue

We have evaluated the effect of feeding ractopamine (Rac), a phenethanolamine lean enhancer being developed for commercial use in finishing pigs, on beta-adrenoceptor (beta-AR) number and ligand-receptor binding affinity in adipose and muscle tissues. Pigs weighing 78 +/- 1 kg were fed Rac (20 mg/kg of diet) for 0 (control), 1, 8, or 24 d before being killed at 105 +/- 1 kg BW. beta-adrenoceptor density (per milligram of protein) was decreased by Rac up to approximately 50% in both the middle and the outer layers of subcutaneous (SQ) adipose tissue. Orthogonal contrasts indicated significant (P < or = .05) linear effects of Rac in middle and outer SQ adipose tissue, and also a significant (P < or = .05) quadratic effect of Rac in the middle layer. Ractopamine did not affect the maximal binding (Bmax) of longissimus muscle. The relative affinity with which the beta-AR population of the tissues examined bound the radioligand ([3H]dihydroalprenolol) was not influenced by Rac. Likewise, feeding Rac had no effect on the affinity of the beta-AR for Rac. The data indicate that a Rac-induced reduction in the Bmax of adipose tissue may account for the diminished in vitro lipolytic potency of exogenous Rac after prolonged periods of Rac feeding, and that Rac-induced desensitization differs between adipose and skeletal muscle tissues.

Serum and pleural fluid levels of CA50 in malignant and tuberculous effusions

The measurement of CA50 in serum and pleural fluid by immunoradiometric assay was presented in 45 (27 malignancy and 18 tuberculosis) patients with pleural effusion. The mean CA50 level in malignant effusion (89.26 +/- 122.32 U ml-1) was significantly higher than that in tuberculous effusion (5.18 +/- 8.65 U ml-1) (P < 0.001). CA50 levels of pleural fluid above an arbitrary level of 20 U ml-1 were found in 78% of malignant fluids and in 6% of tuberculous fluids. The serum CA50 value from 27 patients with malignant effusion (58.67 +/- 85.85 U ml-1) was also higher than that from 18 patients with tuberculous effusion (6.18 +/- 8.37 U ml-1) (P < 0.001). CA50 levels of serum above the same level were found in 58% of patients with malignant fluid and in 6% of patients with tuberculous fluid. The results suggested that the measurement of CA50 in pleural effusion may be helpful in the differential diagnosis between tuberculous and malignant effusions.

Limitations of ractopamine to affect adipose tissue metabolism in swine

To determine the temporal effect of ractopamine (Rac), a phenethanolamine, on adipose lipogenic enzyme activity and gene expression, 20 crossbred barrows were fed Rac (20 mg/kg of diet) for 0, 1, 8, or 24 d before slaughter (105 +/- 1 kg). Ractopamine had no effect (P > .05) on the activity of acetyl-coenzyme A carboxylase or malic enzyme in either the middle or outer layers of subcutaneous adipose tissue. Similarly, mRNA abundance for acetyl-coenzyme A carboxylase and the glucose transport proteins Glut 1 and Glut 4 were not affected by Rac in either adipose depot. Despite the inability of Rac to affect adipose tissue metabolism, Rac increased nitrogen retention, longissimus muscle area, and alpha-actin gene expression in skeletal muscle. Results indicate that Rac was not a functional beta-adrenergic agonist toward adipose tissue in this study. We suggest that the response to Rac in adipose tissue is masked by a combination of factors including tissue insensitivity, Rac-dose limitation, inherent partial agonism of Rac, and beta-adrenoceptor down-regulation.

Cloning the partial cDNAs of mu-calpain and m-calpain from porcine skeletal muscle

Calpains are non-lysosomal proteases involved in myofibrillar protein degradation. To facilitate studying the expression of the porcine calpain genes and their influence on protein accretion, we have cloned partial cDNAs for mu- and m-calpain from porcine skeletal muscle via PCR amplification. A 289 bp fragment for mu-calpain and a 629 bp fragment for m-calpain were cloned into the EcoRV site of pBluescript II KS+ vector. The nucleotide sequence for porcine mu-calpain and m-calpain were 92% and 90% identical to corresponding regions of rabbit mu- and m-calpain, respectively. The deduced amino acid sequences for both mu- and m-calpain share 94% identity with respective rabbit mu- and m-calpains. Isoform specificity was validated by Southern hybridization of mu- and m-calpain probes with cloned mu- and m-calpain fragments and Northern hybridization with pig muscle mRNA. These clones will be used to evaluate the role of calpain expression in muscle hypertrophy.

[Immunohistochemical localization and serum testing for ferritin in malignant histiocytosis]

Localization of ferritin with immunohistochemical staining was carried out in thirty six cases of malignant histiocytosis (MH). The positivity rate for ferritin was 100 per cent. Ferritin was found to exist in the cytoplasm of the tumor cells. Image analysis showed that ferritin level in the well-differentiated histiocytes (1.2314) was higher than that in the atypical histiocytes (0.7181) (P < 0.01). Ten MH patients showed surprising high serum ferritin concentration (1482.3 ng/ml) than that in normal. Our data suggest that ferritin is the tumor associated antigen in MH. The synthesis and release of ferritin by MH tumor cells is the important cause for the high concentration of serum ferritin in patients.

[Splenic embolization therapy of idiopathic thrombocytopenic purpura]

21 patients with chronic idiopathic thrombocytopenic purpura (ITP) and 3 patients with Evan's syndrome underwent partial splenic embolization (PSE). 22 patients underwent PSE once, while 2 patients were treated twice, thus a total of 26 procedures were carried out. Follow-up 3 months after embolization was available in all the 24 patients for their response to embolization therapy. 16 patients (67%) achieved complete remission (platelets greater than 100 x 10(9)/L) and 4 (17%) partial remission (platelets greater than 84 x 10(9)/L) after splenic embolization. A total efficacy rate of 83% was observed. This response to embolization after transcatheter vessel occlusion 3 months after is similar to the reported results of splenectomy. Not only may the morbidity and mortality associated with surgical splenectomy be avoided, but also the noninfarcted spleen may continue to provide immunologic functions. The most important experience in this series, however, was the emphasis on partial (60-70%) rather than total splenic arterial embolization. The sequestration site of platelets was associated with the outcome of splenic embolization. More splenic sequestration sites were found in responders, to the therapy.

Effects of the beta-adrenergic agonist isoproterenol on protein accretion, synthesis, and degradation in primary chicken muscle cell cultures

Seven-day-old primary myotube cultures derived from embryonic chicken limb muscles were used to determine the effects of the beta-adrenergic agonist isoproterenol (ISO) on muscle protein metabolism in vitro. Isoproterenol increased (P less than .05) total protein accumulation after 2 h of acute exposure and after chronic exposure for 24 and 48 h. Isoproterenol did not consistently retard rate of protein degradation of the total protein (TP), myofibrillar protein (MFP) pools, and myosin heavy-chain subunit (MHC); degradation of these protein pools tended to be slowed by inclusion of ISO in the culture medium. After acute treatment of 1 X 10(-4) M ISO for 2 h, TP, but not MFP and MHC, synthesis rate was increased, and after chronic exposure to 1 X 10(-4), 1 X 10(-5), and 1 X 10(-6) M ISO, TP, MFP, and MHC synthesis rates and net accumulation of TP, cytoplasmic protein, and MHC fractions were enhanced (P less than .05). The beta-adrenergic antagonist propranolol (1 X 10(-5) M) blocked chronic stimulatory effects of ISO. Furthermore, after 48 h of exposure to ISO, effects on protein synthesis were less pronounced than those observed after 24 h of exposure. Isoproterenol imparted a more pronounced effect on protein synthesis than on protein degradation, indicating that increased muscle protein accretion observed in animals after ISO treatment is likely a function of enhanced protein synthesis.

[Correlation study of in vitro tests with clinical response to ALG therapy in patients with severe aplastic anemia]

Fourteen patients with severe aplastic anemia were treated with antilymphocyte globulin (ALG). Eight were studied with co-culture of patient's lymphocytes with normal bone marrow cells. Suppression of CFU-C was prevented by pretreatment of T lymphocytes with anti-T lymphocyte McAb in four patients and concordance with clinical outcome was observed only in two patients. Conclusive in vivo therapy result for this correspondence are lacking. Seven patients received fetal liver cell suspension infusion 24-36 hours after completing ALG therapy and remission were "more complete" in three cases with good response. Response of treatment in the fourteen patients was as follows: eight had complete or partial responses and the remaining did not respond or died (42.8%).

Effects of contaminants in blood-collection devices on measurements of therapeutic drugs

Substances in evacuated blood-collection devices produce gas-chromatographic peaks with retention times similar to those of drugs. All tubes tested except the serum separator tubes contained tris(2-butoxyethyl) phosphate, as determined by mass spectrometry. In addition, the partition coefficient during the solvent-extraction step increased for some drugs by as much as 40%, while for other drugs it decreased by as much as 30%, depending on the drug and the collection tube. The Becton Dickinson serum separator tube also contains several other compounds identified by mass spectrometry to be dibasic esters used in the preparation of the polyester gel. The Corning serum separator tube and the Venoject serum tube contain still other impurities. The Becton Dickinson royal-blue-stoppered tube contained the least amount of impurities of the tubes tested. CVs of 25 commonly measured drugs in plasma pools increased from 5% for samples collected in glass tubes to greater than 20% for samples collected in evacuated blood-collection tubes. Clearly, accuracy and precision of measurements of therapeutic drugs can be seriously compromised if an inappropriate blood-collection device is used.

Effects of contaminants in blood-collection devices on measurements of therapeutic drugs

Substances in evacuated blood-collection devices produce gas-chromatographic peaks with retention times similar to those of drugs. All tubes tested except the serum separator tubes contained tris(2-butoxyethyl) phosphate, as determined by mass spectrometry. In addition, the partition coefficient during the solvent-extraction step increased for some drugs by as much as 40%, while for other drugs it decreased by as much as 30%, depending on the drug and the collection tube. The Becton Dickinson serum separator tube also contains several other compounds identified by mass spectrometry to be dibasic esters used in the preparation of the polyester gel. The Corning serum separator tube and the Venoject serum tube contain still other impurities. The Becton Dickinson royal-blue-stoppered tube contained the least amount of impurities of the tubes tested. CVs of 25 commonly measured drugs in plasma pools increased from 5% for samples collected in glass tubes to greater than 20% for samples collected in evacuated blood-collection tubes. Clearly, accuracy and precision of measurements of therapeutic drugs can be seriously compromised if an inappropriate blood-collection device is used.