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PubMed1985

Standardization of prekallikrein activator (PKA): the 1st International Standard for PKA.

A international collaborative study was carried out to establish an international standard for prekallikrein activator (PKA). The candidate material, coded 82/530, was assayed against the Office of Biologics (FDA) PKA reference preparation No. 2 (OoB 2) and the 1st British Reference Preparation for PKA. There was good agreement between participant laboratories on the relative PKA activity of the three preparations. Preparation 82/530 has been established by the World Health Organization as the 1st I.S. for PKA, with an assigned potency of 85 International Units per ampoule.

Factor XII↗
PubMed1987

Recommendations for reference method for haemoglobinometry in human blood (ICSH standard 1986) and specifications for international haemiglobincyanide reference preparation (3rd edition). International Committee for Standardization in Haematology; Expert Panel on Haemoglobinometry.

Scientific symposia on haemoglobinometry were held at the 9th Congress of the European Society of Haematology, Lisbon, 1963 (ESH 1964) and the 10th Congress of the International Society of Haematology (ISH), Stockholm, 1964 (ISH 1965). The International Committee for Standardization in Haematology (ICSH) made recommendations endorsed by the General Assembly of ICSH in Sydney on 23 August 1966 (ICSH 1967), for a reference method for haemoglobinometry and for the manufacture and distribution of an international reference preparation. Further symposia were held at the 12th Congress of the ISH, New York, 1968 (Astaldi, Sirtori & Vanzetti 1979) and at the 13th Congress of ISH, Munich, 1970 (Izak & Lewis 1972). The recommendations were reissued in 1978 (ISH 1978). On the basis of continuing experimental studies, the reference method and the specifications for the international reference preparation have been modified. The revised recommendations are described in this document.

Drug Stability↗
PubMed2004

Standardization of factor VIII and von Willebrand factor in plasma: calibration of the WHO 5th International Standard (02/150).

Calibration of the 5th International Standard factor (F)VIII/von Willebrand factor in plasma (02/150) (5th IS) for five parameters [factor VIII: coagulant activity (FVIII:C); FVIII: antigen (FVIII:Ag), von Willebrand factor: antigen (VWF:Ag), von Willebrand factor: ristocetin cofactor (VWF:RCo), von Willebrand factor: collagen binding (VWF:CB)] was achieved through an international collaborative study involving 37 laboratories. Estimates calculated relative to the previous 4th IS and locally prepared normal plasma pools were not significantly different for estimates of FVIII:Ag, VWF:Ag, VWF:RCo and VWF:CB and hence mean values calculated relative to the 4th IS of 0.94, 0.91, 0.78 and 0.94 IU ampoule(-1), respectively, were assigned. However, estimates for FVIII:C relative to the fresh normal pools (mean 0.61 IU ampoule(-1)) were significantly lower than estimates relative to the 4th IS (mean 0.68 IU ampoule(-1)). In consideration of the good stability of FVIII:C in the 4th IS and the variability of estimates relative to the local pools it was agreed to assign the mean value obtained relative to the 4th IS of 0.68 IU ampoule(-1). For all five parameters the interlaboratory variability (geometric coefficient of variation, GCV%) was larger for estimates calculated relative to the normal pools (range 12.6-16.5%) when compared with estimates calculated relative to the 4th IS (range 3.5-8.3%). An accelerated degradation study performed in six laboratories indicated that the five calibrated parameters are extremely stable when ampoules are stored at -20 degrees C. Mean estimates of predicted loss per year at -20 degrees C ranged from 0% for VWF:CB to 0.029% for VWF:RCo. The 5th IS (02/150) was established by the World Health Organization in November 2003.

Blood Coagulation↗
PubMed1984

Differential ethnic standards for lung functions, or one standard for all?

The multiple regression equation predicting lung function values for a study population of South African Blacks is compared with equations predicting normal values for Blacks elsewhere, and in almost all cases is found to predict higher values. This is so despite the study population's high prevalence of respiratory disease and long history of exposure to crocidolite asbestos dust. This anomalous finding is explored in terms of some problems with studies generating normal values. In particular, the confounding effect of social class status on ethnic determinants of lung function is considered. Low 'normal' values for Blacks reported from South Africa and elsewhere are examined. The disadvantages to workers of being evaluated in relation to low norms are discussed in terms of preventive medicine and workmen's compensation. The application of a universal standard for all is proposed.

Adult↗
PubMed1984

[Standardization of cholera vaccine and preparation of a national reference standard].

The antigenic potency of the proposed national reference preparations in comparison with that of the corresponding international reference preparations was studied by means of the active protection test in mice. The antigenic potency of the proposed national reference preparations for Inaba and Ogawa was found to be the same or even greater than the antigenic potency of the international reference preparations for cholera vaccine. A high level of antigenic activity was observed during comparison of a production lot of cholera divaccine with the international reference preparation and the national reference preparation in parallel tests. The proposed national reference preparations for Inaba and Ogawa may be used for evaluating the antigenic potency of the lot of cholera vaccine produced in Bulgaria as the standard preparation.

Animals↗
PubMed1998

A detailed comparison of the performance of the standard versus the Nijmegen modification of the Bethesda assay in detecting factor VIII:C inhibitors in the haemophilia A population of Canada. Association of Hemophilia Centre Directors of Canada. Factor VIII/IX Subcommittee of Scientific and Standardization Committee of International Society on Thrombosis and Haemostasis.

The Bethesda assay is widely used to monitor the development and progress of Factor VIII:C inhibitors. Factor VIII stability in the substrate plasma (normal pool) is compromised by pH shift and reduction in protein concentration. Preliminary study, by Verbruggen and colleagues (8), suggested a reduction in spuriously positive assay results may result from buffering the normal pool plasma substrate with imidazole to pH 7.4 and substituting Factor VIII deficient plasma for imidazole buffer in the control incubation mix. These laboratory findings have now been confirmed by the performance of both the standard and the modified Bethesda assays in parallel on 877 patient samples screened during the Factor VIII:C Inhibitor Surveillance Program instituted following the conversion of all Canadian haemophilia A patients to recombinant Factor VIII. Although this study does not address the question of the clinical significance of spurious positive assays, these laboratory findings do support the conclusions of Verbruggen and the modified assay has recently been endorsed by the Factor VIII/IX Subcommittee of the SSC.

Antigen-Antibody Reactions↗
PubMed1986

Tolerance intervals for standards in ultrasound measurements: determination of BPD standards.

Standards for the relationship between BPD and gestational age are used for the assessment of fetal size. We measured the BPD in 310 women with exact gestational age in a cross-sectional study. Two types of BPD charts were constructed based on tolerance intervals: directly from measurements and after model fitting. We found that the tolerance intervals based on the model are smoother and narrower than those achieved by direct determinations. The fit, advantages, and prospects of the model are discussed.

Body Constitution↗
PubMed1995

Quantification of particle sizes with metal replication under standard freeze-etching conditions: a gold ball standard for calibrating shadow widths was used to measure freeze-etched globular proteins.

The real size of platinum-carbon (Pt-C) replicated particles is not directly equivalent to either its metal-coated diameter or its shadow width. This paper describes two indirect methods, shadow widths and coated particle diameters, for determining a particle's actual size beneath a Pt-C replication film. Both produce equivalent measurements using the same standardized conditions: 2.3 nm Pt-C films deposited at a 45 degree angle on an approximately -100 degrees C surface in a 10(-6) torr vacuum. For the first method, gold balls nucleated in a partial pressure of helium and deposited on flat indirect carbon films (root mean square roughness of 0.8 nm) on 400 mesh grids were used as test particles for calibrating shadow widths as a function of particle size. The gold ball test specimens were replicated, and a distribution of Pt-C shadow widths orthogonal to the Pt-C deposition direction was measured and averaged for gold balls 1.5 +/- 0.25 nm, 2.0 +/- 0.25 nm, etc. The diameter of each gold ball was measured within the Pt-C film along with its shadow width because the Pt-C did not obscure or adhere well to the gold. The shadow width distributions for each gold size do not differ significantly from log normal. Two proteins, the lactose repressor and the mitochondrial ATPase, F1, were also used as replication test objects. Negative staining of both proteins was conducted to measure their average diameters. In the second method, a distribution of Pt-C-coated lac repressor diameters perpendicular to the shadow direction was measured. The Pt-C film thickness measured on the quartz crystal monitor was subtracted from the average metal-coated protein diameter to obtain the lac repressor's diameter. The Pt-C-coated particle diameter distributions also did not differ significantly from log normal. While doing this work it was discovered that outgassing the Pt-C electron gun greatly affected Pt-C film granularity: 19 sec produced a high contrast, granular Pt-C film, whereas 120 sec yielded a low contrast, less granular Pt-C film. Both gold balls and protein particles were subjected in separate experiments to either 19 or 120 sec of outgassing of the Pt-C gun prior to Pt-C replication. Outgassing had a profound effect on the average size of the Pt-C shadow widths on both gold and protein particles. The Pt-C gun outgassing procedure also determined the smallest replicated particle that could be resolved. The frequency of some smaller gold ball sizes detected after replication was reduced disproportionately with 19 sec vs. 120 sec outgassing. However, Pt-C gun outgassing did not affect the average measured diameter of the Pt-C-coated protein particles. The "geometric assumption" that each metal-coated particle creates a shadow width the same size as the metal-coated particle diameter was tested using a globular protein. Pt-C replication of protein particles at a 45 degree and 20 degree angle could not confirm the geometric assumption because an average shadow width was always significantly larger than its average Pt-C-coated particle diameter. A model for how the large shadow widths are formed is presented. Gold balls were also replicated at a 45 degree angle with current high resolution conditions at a substrate temperature of -185 degrees C, and the results of these replicas were compared to the results reported here at approximately -100 degrees C.

Calibration↗
PubMed1996

Report on the progress of standardization of the G-banded canine (Canis familiaris) karyotype. Committee for the Standardized Karyotype of the Dog (Canis familiaris).

Karyotyping of dog chromosomes is a difficult task owing to the high diploid number of chromosomes (2n = 78) and the similar morphology of autosomes, all of which are acrocentrics. In this report 22 of the 39 G-banded chromosome pairs and their corresponding ideograms have been standardized. The ideogram comprises altogether 235 bands. The need for the introduction of molecular techniques such as chromosome painting and physical mapping of genetic markers for the identification of small acrocentrics is discussed.

Animals↗
PubMed2005

Development and reliability of a standard rating system for outcome measurement of foot and ankle disorders II: interclinician and intraclinician reliability and validity of the newly established standard rating scales and Japanese Orthopaedic Association rating scale.

BACKGROUND: This study evaluated the validity and inter- and intraclinician reliability of (1) the Japanese Society of Surgery of the Foot (JSSF) standard rating system for four sites [ankle-hindfoot (AH), midfoot (MF), hallux (HL), and lesser toe (LT)] and the rheumatoid arthritis (RA) foot and ankle scale and (2) the Japanese Orthopaedic Association's foot rating scale (JOA scale). METHODS: Clinicians from the same institute independently evaluated participating patients from their institute by two evaluations at a 1- to 4-week interval. Statistical evaluation was as follows. (1) The intraclass correlation coefficient (ICC) was calculated from data collected from at least two examinations of each patient by at least two evaluating clinicians (Data A). (2) Total scores for the two evaluations were determined from the distribution of differences in data between the two evaluations (Data B); each item was evaluated by determining Cohen's coefficient of agreement. (3) The relation between patient satisfaction and total score was investigated only for patients who underwent surgery (Data C). Spearman's rank correlation coefficient was obtained. RESULTS: Participants were 65 clinicians and 610 patients, including those with disorders of the AH (313), MF (47), HL (153), and LT (50) and those with RA (47). From Data A, the ICC was high for AH and HL by JSSF scales and for AH, MF, and LT by the JOA scale. From Data B, the coefficient showed high validity for both scales for AH, with almost no difference between the two scales; the validity for HL was higher with the JOA scale than with the JSSF scale. From Data C, correlations were significant between patient satisfaction and outcome for AH and HL by the JSSF scales and for AH, HL, and LT by the JOA scale. CONCLUSIONS: The validity of both scales was high. Clinical evaluation of the therapeutic results using these scales would be highly reliable.

Ankle↗
PubMed2006

The standard is still the standard or why an INR of 2-3 is still the optimal intensity for secondary prevention of venous thromboembolism.

The optimal intensity of warfarin anticoagulation for secondary prevention of venous thromboembolism is debatable. Recent studies have shed light on the issue. The two pivotal studies, ELATE and PREVENT, are reviewed and discussed. Although the ELATE and PREVENT studies offer different conclusions, the results of the two studies are consistent with each other. Low intensity warfarin is more efficacious than placebo, although it is less efficacious than standard intensity and offers no safety advantage. For long term secondary prophylaxis of spontaneous venous thromboembolism, the optimal INR intensity of warfarin remains 2.0-3.0.

Anticoagulants↗
PubMed1992

Paralytic shellfish poison (saxitoxin family) bioassays: automated endpoint determination and standardization of the in vitro tissue culture bioassay, and comparison with the standard mouse bioassay.

Mouse neuroblastoma cells swell and eventually lyse upon exposure to veratridine, which, when added together with ouabain, enhances sodium ion influx. In the presence of saxitoxin (STX), which blocks sodium channels, the action of the other two compounds is inhibited and the cells remain morphologically normal. A tissue culture bioassay using mouse neuroblastoma cells, developed by Kogure and colleagues, takes advantage of these principles; in this bioassay, the fraction of the cells protected from the actions of ouabain and veratridine is in direct proportion to the concentration of STX and its analogues. We have modified this bioassay, improving its convenience and speed by eliminating the need to count individual cells to determine the saxitoxin equivalents, and instead have employed a microplate reader for automated determinations of absorbances of crystal violet from stained neuroblastoma cells. When these changes and other minor technical modifications were tested in the tissue culture bioassay systematically, we found the lower detection limit to be around 10 ng STX equivalents (eq) per ml of extract ( = 2.0 micrograms STX eq/100 g shellfish tissue). Our version of the tissue culture bioassay was compared with the standard mouse bioassay using 10 acid extracts of dinoflagellates (Alexandrium excavata and A. fundyense) and 47 AOAC extracts of shellfish tissues. The tissue culture bioassay provided results virtually identical to those obtained with the mouse bioassay (r > 0.96), and moreover, was considerably more sensitive. The results gained from high performance liquid chromatographic (HPLC) analysis of 12 of the same extracts were less consistent when compared with the results from both bioassay methods. The automated tissue culture (neuroblastoma cell) bioassay may be a valid alternative to live animal testing for paralytic shellfish poisoning.

Animals↗
PubMedDate not supplied

Professionals' standards of "normal" behavior with anatomical dolls and factors that influence these standards.

Do professionals have a consistent standard of what constitutes normal behavior with anatomical dolls? To answer this question, 201 professionals who work with child sexual abuse victims were asked to rate the normalcy of various behaviors with the dolls for nonabused children ages 2 to 5.9 years. The majority of respondents agreed that overtly sexual behaviors, such as demonstrating oral-genital contact or vaginal intercourse, were abnormal for nonabused children. For less obvious behaviors, such as touching the sex parts of dolls, there was more disagreement among professionals about what these behaviors mean. The ratings of these ambiguous behaviors varied depending on profession of the respondent, gender of the respondent, and number of years of experience. Law enforcement professionals, women, and those with the least amount of experience were more likely to view ambiguous behaviors as abnormal. These findings are discussed in the context of past research, with suggestions for future studies.

Child↗
PubMed2005

Nesiritide added to standard care favorably reduces systolic blood pressure compared with standard care alone in patients with acute decompensated heart failure.

The Prospective Randomized Outcomes study of Acutely decompensated Congestive heart failure Treated Initially as Outpatients with Nesiritide (PROACTION) trial evaluated the safety of nesiritide administration in the emergency department in patients with decompensated heart failure. Patients (N=237) were treated for at least 12 hours with standard care plus either intravenous nesiritide or placebo. Compared to placebo, nesiritide favorably decreased systolic blood pressure (SBP) in patients with elevated baseline SBP, without negatively impacting patients with lower baseline SBP (SBP, >140 mm Hg: nesiritide, -28.7 mm Hg, vs placebo, -8.4 mm Hg [P<.001]; SBP, 101-140 mm Hg: nesiritide, -12.3 mm Hg, vs placebo, -5 mm Hg [P<.017]; SBP, <101 mm Hg: nesiritide, -1.2 mm Hg vs placebo, +16.7 mm Hg [P<.03]). Both treatment groups had similar incidences of symptomatic and asymptomatic hypotension. These data demonstrate that early administration of nesiritide in the emergency department is a safe and effective treatment of heart failure.

Aged↗
PubMed2004

A phase II, double-masked, randomized, placebo-controlled evaluation of a human monoclonal anti-Cytomegalovirus antibody (MSL-109) in combination with standard therapy versus standard therapy alone in the treatment of AIDS patients with Cytomegalovirus retinitis.

ACTG 266 was designed as a randomized study to evaluate two doses of the human monoclonal antibody directed against CMV gH (MSL-109) versus placebo, each in combination with standard antiviral therapy for the treatment of newly diagnosed Cytomegalovirus (CMV) retinitis in AIDS patients. A total of 82 subjects were enrolled and received either placebo (n = 28), or MSL-109 at 15 mg (n = 26) or 60 mg (n = 28) every 2 weeks until disease progression was diagnosed. The primary endpoint, disease progression, was determined by masked reading of retinal photographs taken every 4 weeks read by a single investigator. The median time to progression was 8.0, 8.3, and 12.1 weeks in the placebo, MSL-109 15mg and MSL-109 60 mg cohorts, respectively (P = 0.087, placebo versus 60 mg cohort). There were 22 deaths during the study period (9, 9, and 4 in the placebo, MSL-109 15 mg and MSL-109 60 mg cohorts, respectively (P = 0.0058, placebo versus 60 mg cohort)). MSL-109 was well tolerated with no significant adverse events attributable to study medication. The unexplained survival advantage in the higher dose cohort was discordant with the findings of the parallel Studies of Ocular Complications of AIDS Research Group (SOCA)-Monoclonal Anti-CMV Retinitis Trial (MACRT), which was prematurely halted because of increased mortality in subjects treated with high-dose MSL-109, recognizing that A266 enrolled subjects with newly diagnosed, whereas the MACRT enrolled subjects with relapsed, CMV retinitis.

AIDS-Related Opportunistic Infections↗
PubMed1998

[Standardized ultrasound examination of the ankle joint. Clarification of ultrasound standard image sections by corresponding MRI sections].

AIM: The sonographical examination of the ankle was demonstrated in five standard cross-sections presented by the DEGUM (German Society for the Development of Ultrasonography in the Locomotor Apparatus) and compared with corresponding MRI cross-sections. METHOD: The sonographical examination was done in a real-time method with an ultrasound unit Type Versa (Siemens, Erlangen, Germany) and with a linear transducer (frequency 7.5 Mhz). The MRI tomographies were taken in two planes with the unit Type Magnetom (Siemens, Erlangen, Germany) with a 1.5 Tesla head-coil in T1- and T2-weighted spin echo sequences. RESULTS: Focus on the ventral, lateral and dorsal region provided a good overview of the superior ankle joint and the periarticular soft tissues. CONCLUSION: Being a cross-sectional method, the sonographical examination of the ankle joint offers additional information with regard to pathological changes of the joint and the periarticular soft-tissues.

Adult↗
PubMedDate not supplied

A comparison of the U.S. EPA FIFRA GLP standards with the U.S. FDA GLP standards for nonclinical laboratory studies.

In the early 1980's both the Environmental Protection Agency and the Food and Drug Administration were receiving studies on the products that they regulate that were unscientifically sound, some even being fraudulent. Studies were being submitted that had not been done under sound scientific practice; data were missing; necessary documentation to reconstruct the study, also known as an audit trail, was not in place, it was this evidence that lead to the Good Laboratory Practice Standards (GLPs) being codified and becoming regulation. The GLPs were meant to assure that studies submitted to the agencies for the registration of products for which they were responsible would protect the environment, and, the safety and health of the public.

Animals↗