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The article describes the results of investigations of the sub-recent assemblages of silica phytoliths in top soils of various modern plant communities of the Middle Volga region in Tatarstan, Samarskaya and Ulyanovskaya oblasts conducted in 2017–2020. Counts of various phytolith morphotypes from 40 samples suggest a relatively low level of vegetation community specificity as revealed by multivariate statistical analyses. Nevertheless, coniferous and mixed forests can be distinguished based on the presence of a suite of conifer phytoliths, while steppes can be identified based on high proportion of rondels. Deciduous forests of the region can be detected based on high proportion of straight elongates and acutous bulbosus (trichome) type. Some matchings are made to 10 archaeological samples from various strata and ages across the region. Such samples reveal high proportion of cultured grass phytoliths and are most similar to steppes or agricultural assemblages in the modern dataset.

OBJECTIVES: Our study tested the effectiveness of network methods for identifying opinion leaders and for constructing groups. METHODS: Three conditions-random, teacher, and network--ere randomly assigned to 84 6th-grade classrooms within 16 schools. Pre- and postcurriculum data on mediators of tobacco use were collected from 1961 students. Peer leaders in the network condition were identified by student nominations, and those leaders were matched with the students who nominated them. RESULTS: Students in the network condition relative to the random condition liked the prevention program more and had improved attitudes (beta = -0.06; P <.01), improved self-efficacy (beta = -0.10; P <.001), and decreased intention to smoke (adjusted odds ratio [OR] = 0.46; 95% confidence interval [CI] = 0.38, 0.55). CONCLUSIONS: The network method was the most effective way to structure the program. Future programs may refine this technique and use it in other settings. [ABSTRACT FROM AUTHOR]

The health risks that arise from environmental exposures vary widely within and across human populations, and these differences are largely determined by genetic variation and gene-by-environment (gene-environment) interactions. However, risk assessment in laboratory mice typically involves isogenic strains and therefore, does not account for these known genetic effects. In this context, genetically heterogenous cell lines from laboratory mice are promising tools for population-based screening because they provide a way to introduce genetic variation in risk assessment without increasing animal use. Cell lines from genetic reference populations of laboratory mice offer genetic diversity, power for genetic mapping, and potentially, predictive value for in vivo experimentation in genetically matched individuals. To explore this further, we derived a panel of fibroblast lines from a genetic reference population of laboratory mice (the Diversity Outbred, DO). We then used high-content imaging to capture hundreds of cell morphology traits in cells exposed to the oxidative stress-inducing arsenic metabolite monomethylarsonous acid (MMAIII). We employed dose-response modeling to capture latent parameters of response and we then used these parameters to identify several hundred cell morphology quantitative trait loci (cmQTL). Response cmQTL encompass genes with established associations with cellular responses to arsenic exposure, including Abcc4 and Txnrd1, as well as novel gene candidates like Xrcc2. Moreover, baseline trait cmQTL highlight the influence of natural variation on fundamental aspects of nuclear morphology. We show that the natural variants influencing response include both coding and non-coding variation, and that cmQTL haplotypes can be used to predict response in orthogonal cell lines. Our study sheds light on the major molecular initiating events of oxidative stress that are under genetic regulation, including the NRF2-mediated antioxidant response, cellular detoxification pathways, DNA damage repair response, and cell death trajectories., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 O’Connor et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Many studies have been directed at understanding mechanisms of tau aggregation and therapeutics, nearly all focusing on the brain. It is critical to understand the presence of tau in peripheral tissues since this may provide new insights into disease progression and selective vulnerability. The current study sought to determine the presence of select tau species in peripheral tissues in elderly individuals and across an array of tauopathies. Using formalin fixed paraffin embedded sections, we examined abdominal skin, submandibular gland, and sigmoid colon among 69 clinicopathologically defined cases: 19 lacking a clinical neuropathological diagnosis (normal controls), 26 progressive supranuclear palsy (PSP), 21 Alzheimer's disease (AD), and 3 with corticobasal degeneration (CBD). Immunohistochemistry was performed using antibodies for "total" tau (HT7) and two phosphorylated tau species (AT8 and pT231). HT7 staining of abdominal skin revealed immunoreactivity of potential nerve elements in 5% of cases (1 AD, 1 AD/PSP, and 1 CBD out of 55 cases examined); skin sections lacked AT8 and pT231 immunoreactive nerve elements. Submandibular glands from all cases had HT7 immunoreactive nerve elements; while pT231 was present in 92% of cases, and AT8 in only 3 cases (2 AD and one AD/PSP case). In sigmoid colon, HT7 immunoreactivity was present in all but 2 cases (97%), pT231 in 54%, and AT8 was present in only 5/62 cases (8%). These data suggest select tau species in CNS tauopathies do not have a high propensity to spread to the periphery and this may hold clues for the understanding of CNS tau pathogenicity and vulnerability., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: The Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) has recently established pediatric age- and sex-specific reference intervals for over 85 biochemical markers on the Abbott Architect system. Previously, CALIPER reference intervals for several biochemical markers were successfully transferred from Abbott assays to Roche, Beckman, Ortho, and Siemens assays. This study further broadens the CALIPER database by performing transference and verification for 52 biochemical assays on the Roche cobas 6000 and the Roche Modular P., Design and Methods: Using CLSI C28-A3 and EP9-A2 guidelines, transference of the CALIPER reference intervals was attempted for 16 assays on the Roche cobas 6000 and 36 on the Modular P. Calculated reference intervals were further verified using 100 healthy CALIPER samples., Results: Most assays showed strong correlation between assay systems and were transferable from Abbott to the Roche cobas 6000 (81%) and the Modular P (86%). Bicarbonate and magnesium were not transferable on either system and calcium and prealbumin were not transferable to the Modular P. Of the transferable analytes, 62% and 61% were verified on the cobas 6000 and the Modular P, respectively., Conclusions: This study extends the utility of the CALIPER database to two additional analytical systems, which facilitates the broad application of CALIPER reference intervals at pediatric centers utilizing Roche biochemical assays. Transference studies across different analytical platforms can later be collectively analyzed in an attempt to develop common reference intervals across all clinical chemistry instruments to harmonize laboratory test interpretation in diagnosis and monitoring of pediatric disease., (Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)

Purpose: This study examines maternal and child health core competencies and leadership characteristics of undergraduate students following participation in the Maternal and Child Health Careers/Research Initiatives for Student Enhancement-Undergraduate Program (MCHC/RISE-UP). MCHC/RISE-UP is a 10-week public health leadership program designed to promote diversity in public health workforce through mentored research, community engagement and advocacy, and clinical experiences for undergraduate students., Description: The MCHC/RISE-UP is a national consortium of University Centers for Excellence in Developmental Disabilities including, (1) Kennedy Krieger Institute (Kennedy Krieger, lead institution) partnering with Morgan State University, a Historically Black University, (2) the University of South Dakota partnering with Tribal Serving Institutions; and (3) the University of Southern California Children's Hospital-Los Angeles and their partner institution, California State University Los Angeles, a Hispanic Serving Institution., Assessment: Eighty-four junior and senior undergraduates and recent baccalaureate degree students who participated in the MCHC/RISE-UP worked on 48 maternal and child health projects. Following the MCHC/RISE-UP, students demonstrated statistically significant improvements in all maternal and child health core competencies. Transformational leadership characteristics also increased (mean increase 9.4, 95% CI 7.2-11.8; p < 0.001). At closing interview, over twice as many students endorsed a public health career goal compared to program admission (17.9 vs. 57.7%; p = 0.022)., Conclusion: Multi-institutional collaborative public health leadership programs may extend the reach and recruitment of diverse students into the maternal and child health field. Experiential, didactic, and mentored learning opportunities may enhance student integration of maternal and child health competencies and transformational leadership characteristics.

Transgender women have a higher prevalence of drug use, HIV, drug use, and sex work than the general population. This article explores the interaction of these variables and discusses how sex work and drug use behaviors contribute to the high rates of HIV. A model predicting HIV rates with sex work and drug use as well as these behaviors in the transgender woman's social network is presented. Challenges to intervening with transgender women, as well as suggestions and criteria for successful interventions, are discussed.

Problem: Gang membership is an indicator of chronic substance use. Social network studies indicate that substance use in youth is related to substance use in friends and family; however, no such analyses among gang youth have been conducted., Methods: Interviews were conducted with a sample of young gang members (n = 60) in Los Angeles. Univariate analyses were conducted., Findings: Cigarette use in gang members was strongly associated with cigarette use in friendship networks. There were no associations for use of alcohol and marijuana., Conclusions: Few associations emerged between substance use in participants and their friends/family. Possible explanations for these findings are presented., (© 2013 Wiley Periodicals, Inc.)

Background: Currently there is no reliable method suitable for routine measurement of serum free testosterone (FT)., Aim: To develop such a method involving liquid chromatography tandem mass spectrometry (LC-IDMS/MS) that directly detects and quantifies the FT present in serum., Methods: Ultrafiltrate testosterone obtained from 0.5 mL of serum was partially purified by liquid/liquid extraction and quantified using an Agilent 1200 Series HPLC system coupled to an API 5000 mass spectrometer equipped with an atmospheric pressure chemical ionization ion source. Using split samples serum free testosterone was compared between direct ultrafiltration (UF) coupled LC-MS/MS, analogue FT immunoassay, free testosterone calculated from mass action equations (cFT) and with equilibrium dialysis (ED) coupled LC-MS/MS., Results: Total imprecision determined over twenty runs was <6% at 67 pmol/L and 158 pmol/L FT. The dynamic response was linear up to at least 2500 pmol/L while physical LLOQ (18 % CV) equaled 16 pmol/L. The UF method agreed poorly with analogue immunoassay (correlation coefficient 0.667; bias -81%), somewhat better against cFT when total testosterone was determined by immunoassay (correlation coefficient 0.816, bias 21% ) and still better yet against cFT when total testosterone was determined by LC-MS/MS (correlation coefficient 0.8996, bias 10%). Agreement was closest with ED method (correlation coefficient 0.9779, bias 2.4%)., Conclusion: We present a relatively simple UF coupled LC-MS/MS definitive method that measures serum free testosterone. The method is relatively fast, reliable and is suitable for the routine clinical laboratory practice., (Copyright 2009 Elsevier Inc. All rights reserved.)

Objectives: To develop a rapid convenient-to-implement high performance liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) method for determination of serum testosterone concentration in routine clinical laboratories., Methods: Following extraction by organic solvents, an Agilent 1200 Series HPLC system coupled to an API 5000 mass spectrometer equipped with an atmospheric pressure chemical ionization ion source was used to separate, detect and quantify serum testosterone. Ion-transitions of m/z 289.2-->109.1 and 294.2-->113.2 were used to monitor testosterone and testosterone-2,2,4,6,6-d(5), respectively., Results: Functional sensitivity was 0.056 nmol/L (CV 20%). Within-run and total imprecision were 4.6% and 5.2% at 1.3 nmol/L, 2.4% and 4.3% at 11.0 nmol/L, and 1.9% and 1.9% at 23.4 nmol/L respectively. The LC-MS/MS method agreed closely with three automated immunoassays when the concentration of testosterone exceeded 3 nmol/L. However, the immunoassays showed a positive bias at concentrations below 3 nmol/L., Conclusion: This method provides a rapid, simple, highly selective and sensitive procedure that can be easily used for determination of serum testosterone in routine clinical laboratories. It measures serum testosterone precisely and accurately at concentrations found in children and adults of both genders.

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed., Methods: Published reports relevant to use of tumor markers for 5 cancer sites--testicular, prostate, colorectal, breast, and ovarian--were critically reviewed., Results: For testicular cancer, alpha-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. alpha-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is <10 microg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node-negative patients. CA15-3/BR27-29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer., Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

Background: This report presents updated National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines summarizing quality requirements for the use of tumor markers., Methods: One subcommittee developed guidelines for analytical quality relevant to serum and tissue-based tumor markers in current clinical practice. Two other subcommittees formulated recommendations particularly relevant to the developing technologies of microarrays and mass spectrometry., Results: Prerequisites for optimal use of tumor markers in routine practice include formulation of the correct clinical questions to ensure selection of the appropriate test, adherence to good clinical and laboratory practices (e.g., minimization of the risk of incorrect patient and/or specimen identification, tube type, or timing), use of internationally standardized and well-characterized methods, careful adherence to manufacturer instructions, and proactive and timely reactions to information derived from both internal QC and proficiency-testing specimens. Highly desirable procedures include those designed to minimize the risk of the reporting of erroneous results attributable to interferences such as heterophilic antibodies or hook effects, to facilitate the provision of informative clinical reports (e.g., cumulative and/or graphical reports, appropriately derived reference intervals, and interpretative comments), and when possible to integrate these reports with other patient information through electronic health records. Also mandatory is extensive validation encompassing all stages of analysis before introduction of new technologies such as microarrays and mass spectrometry. Provision of high-quality tumor marker services is facilitated by dialogue involving researchers, diagnostic companies, clinical and laboratory users, and regulatory agencies., Conclusions: Implementation of these recommendations, adapted to local practice, should encourage optimization of the clinical use of tumor markers.

Objective: To determine using a simplified study design trimester-specific FT4 reference intervals in pregnancy with the Roche Modular immunoassay in routine use., Design and Methods: Surplus blood from 300 women in each trimester, drawn at documented times in the gestation, and from 40 age-matched nonpregnant women were assayed for FT4, thyroid stimulating hormone (TSH) and antithyroid peroxidase autoantibody (anti-TPO)., Results: After excluding women positive for anti-TPO and with abnormal TSH, reference intervals were calculated as 12.5-19.1 pmol/L (nonpregnant group), 11-19 pmol/L (first trimester), 9.7-17.5 pmol/L (second trimester) and 8.1-15.3 pmol/L (third trimester). 3rd trimester FT4 was significantly lower than that of the second trimester (p<0.001) which, in turn, was lower than that of the first trimester (p<0.001). FT4 reference intervals in pregnancy were significantly lower than in the nonpregnant women (p<0.002)., Conclusions: The observed trimester-specific FT4 reference intervals progressively decline with advancing gestation and differ significantly from one another.

Despite advances in tobacco control, adolescent smoking remains a problem. The smoking status of friends is one of the highest correlates with adolescent smoking. This homophily (commonality of friends based on a given attribute) may be due to either peer pressure, where adolescents adopt the smoking behaviors of their friends, or peer selection, where adolescents choose friends based on their smoking status. This study used structural equation modeling to test a model of peer influence and peer selection on ever smoking by adolescents. The primary analysis of the model did not reach significance, but post hoc analyses did result in a model with good fit. Results indicated that both peer influence and peer selection were occurring, and that peer influence was more salient in the population than was peer selection. Implications of these results for tobacco prevention programs are discussed.

This article reviews several classes of theories to elucidate the relationship between adolescent cigarette smoking and friends' cigarette smoking. Perceived influence theories hinge upon an adolescent's perception of friends' smoking behavior. External influence theories are those in which friends' smoking behavior overtly influences adolescent smoking. Group level theories examine how differences at the level of subculture, gender, and race/ethnicity influence the relationship under study. Network theories are also discussed. A model integrating relevant theories into a longitudinal model representing friend influences on adolescent smoking is presented, along with implications of the results presented for adolescent tobacco prevention programs.

Melatonin may protect against breast cancer. Light and other factors influence melatonin, but the evidence is limited. The authors conducted a study to determine factors related to melatonin. Women volunteers recruited in Toronto, Canada, from 2002 to 2004 collected urine for three nights (winter and summer), took periodic light measurements, and recorded exposures in a diary. The relation of each variable to log-transformed creatinine-corrected 6-sulfatoxymelatonin in overnight urine was determined by use of generalized estimating equation linear regression. The final model was based on 1,054 measurement days from 213 participating women. None of the light variables was related to the log of 6-sulfatoxymelatonin. A significant interaction between season and day length was included in the final model. The most significant factor was duration of exercise (beta = 0.072; p = 0.004, two-tailed), which increased the amount of melatonin produced. Exercise duration later in the day was more significant (beta = 0.108; p = 0.0009, two-tailed). There was no difference between moderate or strenuous exercise. The failure to find a relation between light brightness and melatonin may be due to the difficulty of measuring this, as well as the importance of the light spectrum, which could not be measured. It is possible that the protective effect of exercise with respect to breast cancer may operate in part through an effect on melatonin.

Objectives: Our study tested the effectiveness of network methods for identifying opinion leaders and for constructing groups., Methods: Three conditions-random, teacher, and network--ere randomly assigned to 84 6th-grade classrooms within 16 schools. Pre- and postcurriculum data on mediators of tobacco use were collected from 1961 students. Peer leaders in the network condition were identified by student nominations, and those leaders were matched with the students who nominated them., Results: Students in the network condition relative to the random condition liked the prevention program more and had improved attitudes (beta = -0.06; P <.01), improved self-efficacy (beta = -0.10; P <.001), and decreased intention to smoke (adjusted odds ratio [OR] = 0.46; 95% confidence interval [CI] = 0.38, 0.55)., Conclusions: The network method was the most effective way to structure the program. Future programs may refine this technique and use it in other settings.

Background: Previous studies have documented a high prevalence of tobacco use among Native American adolescents. However, little is known about the smoking behavior of Native American adolescents who live in urban areas. This study used statewide data from California to examine the smoking behavior and related psychosocial risk factors among Native American adolescents living in urban and rural counties., Methods: The Independent Evaluation of the California Tobacco Control Program conducted three population-based statewide surveys of 10th-grade California public school students in 1996, 1998, and 2000. Past-month smoking and psychosocial correlates were examined among 22,440 respondents, including 1060 Native Americans., Results: Native Americans had a 32% excess risk of past-month smoking compared with other ethnic groups. Smoking prevalence did not differ between urban (27.7%) and rural (29.3%) Native Americans. Native Americans reported higher access to cigarettes and exposure to smoking peers than other groups. Those psychosocial variables explained some, but not all, of the excess risk of smoking among Native Americans., Conclusions: Effective smoking prevention and cessation interventions are needed for Native American adolescents in urban and rural areas of California.

Human kallikrein 6 protein is a newly discovered human kallikrein. We determined the amount of human kallikrein 6 in extracts of 182 ovarian tumours and correlated specific activity (ng hK6 mg(-1) total protein) with clinicopathological variables documented at the time of surgical excision and with outcome (progression free survival, overall survival) monitored over a median interval of 62 months. Thirty per cent of the tumours were positive for human kallikrein 6 (>35 ng hK6 mg(-1) total protein). Human kallikrein 6-specific immunohistochemical staining of four ovarian tissues that included benign, borderline and malignant lesions indicated a cytoplasmic location of human kallikrein 6 in tumour cells of epithelial origin, although the intensity of staining was variable. Tumour human kallikrein 6 (ng hK6 mg(-1) total protein) was higher in late stage disease, serous histotype, residual tumour >1 cm and suboptimal debulking (>1 cm) (P<0.05). Univariate analysis revealed that patients with tumour human kallikrein 6 positive specific activity were more likely to suffer progressive disease and to die (hazard ratio 1.71 (P=0.015) and 1.88 (P=0.022), respectively). Survival curves demonstrated the same (P=0.013 and 0.019, respectively). Multivariate analysis revealed that human kallikrein 6 positivity was retained as an independent prognostic variable in several subgroups of patients, namely those with (low) grade I and II tumours (hazard ratio progression free survival 4.3 (P=0.027) and overall survival 4.1 (P=0.023)) and those with optimal debulking (hazard ratio progression free survival 3.8 (P=0.019) and overall survival 5.6 (P=0.011)). We conclude that tumour kallikrein 6 protein levels have utility as an independent adverse prognostic marker in a subgroup of ovarian cancer patients with otherwise apparently good prognosis.

Prostate Specific Antigen (PSA) expression by breast epithelial cells is associated with favorable breast cancer prognosis. In preliminary studies, we found that a nucleotide variation (G-->A) at position -158 in the androgen response element (ARE-1) of the PSA promoter was present in four out of 9 breast tumors examined and in a breast carcinoma cell line. We have now determined the nucleotide composition at position -158 of DNA extracted from 148 well-characterized breast tumors and compared tumor genotype with that of controls without cancer, with tumor PSA concentration and with clinicopathological variables, overall survival and disease free survival. The G-->A base change at position -158 is a polymorphism. Allelotypes were similarly distributed in breast cancer patients and controls. The Mann-Whitney U Test showed a significantly higher tumor PSA concentration in tumors that presented a homozygous G as opposed to homozygous A genotype. Genotype at position -158 was not associated with clinicopathological variables in contingency table analysis. Univariate Cox regression models showed a 28% reduction in risk for death in patients with homozygous G genotype compared to those with homozygous A genotype (P = 0.03). However, ARE-1 genotype did not significantly add to the prognostic power in the multivariate model of overall survival. In summary, the base change at position -158 is a polymorphism that may affect breast cancer prognosis, but further studies are required to confirm this possibility and to investigate the relevance of this polymorphism in terms of breast cancer susceptibility.

We report the measure of prostate-specific antigen (PSA) from extracts of blood dried on filter paper. Five 3-mm (diameter) paper discs containing approximately 25 microL of dried whole blood were punched from the filter paper and extracted with 500 microL of buffer. Recovery of PSA was > 92%. Imprecision of the filter paper procedure was <10% when corresponding whole-blood concentrations were >0.35 micrograms/L. PSA recovery was unaffected whether blood was applied to the filter as one 85-microL aliquots, two 43-microL aliquots, or three 28-microL aliquots. PSA is contained in the plasma fraction. Variation in hematocrit from 0.61 to 0.31 caused <+/-10% change in filter paper PSA. Regression analysis showed: filter paper PSA = 0.86 whole-blood PSA - 0.02; Sy/x = 0.44. Men (153) without prostate cancer gave a 95th percentile of 4.8 micrograms /L. PSA in filter paper dried blood was stable for >1 month at -20 to 37 degrees C and showed no loss of recovery after being mailed to a hot climate. We conclude that the filter paper procedure can reliably distinguish normal from increased concentrations of PSA and that it could facilitate screening to detect occult prostate cancer in large-scale mail-in programs to centralized laboratories.

Objective: A 1-year randomized prospective study was conducted to investigate the efficacy of feedback from split-sample testing as part of a capillary blood glucose quality assurance program., Research Design and Methods: A total of 124 nurses were randomized to either group A (quarterly comparisons with feedback) or group B (no feedback). The measure of nurse accuracy against the laboratory at 0, 6, and 12 months was determined by an additional five to seven split-sample tests without giving feedback to either group. Mean accuracy was determined in terms of percent absolute deviation from the laboratory result and a clinical consensus limit of +/- 20% deviation from the laboratory., Results: By 12 months, there was a significant effect of feedback on nurse agreement with the laboratory method (P = 0.022 when agreement was scored as the mean percent absolute difference and P = 0.002 when agreement was scored in terms of the +/- 20% clinical consensus limit). Nurses in the group who had received no quarterly feedback from split-sample testing produced a 3.5% greater mean percent absolute deviation from the laboratory method and 12% fewer comparisons within the acceptable +/- 20% range., Conclusions: Feedback received from split-sample testing has a significant effect in maintaining accuracy in capillary blood glucose monitoring.

Low (2 ng/ml) and high (40 ng/ml) concentrations of the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate (PMA) were tested for their effect on cultured bovine articular chondrocyte proteoglycan synthesis. In addition, we examined whether PMA could reverse interleukin 1 (IL-1) and nonsteroidal antiinflammatory drug (NSAID) induced inhibition of proteoglycan synthesis. Low concentrations of PMA stimulated proteoglycan synthesis by chondrocytes. High concentrations of PMA had no significant effect. IL-1 and high concentrations of NSAID inhibited proteoglycan production by chondrocytes. Low concentrations of PMA completely reversed IL-1 induced inhibition but did not significantly alter proteoglycan synthesis in the presence of antiinflammatory drugs. On the other hand, high concentrations of PMA had little effect on IL-1 induced inhibition but significantly potentiated the suppression of proteoglycan synthesis induced by 2 of the NSAID tested, indomethacin and flurbiprofen. Assay of PKC activity indicated that PKC levels were down-regulated by high but not by low concentrations of PMA. This suggests that different mechanisms were regulating the effects of low and high concentrations of PMA on proteoglycan synthesis. Although IL-1 and high concentrations of NSAID both suppress proteoglycan synthesis by chondrocytes, their different responses when coincubated with PMA suggest that they act through different pathways.