Artificial Intelligence/Machine Learning-Driven Small Molecule Repurposing via Off-Target Prediction and Transcriptomics

The process of discovering small molecule drugs involves screening numerous compounds and optimizing the most promising ones, both in vitro and in vivo. However, approximately 90% of these optimized candidates fail during trials due to unexpected toxicity or insufficient efficacy. Current concepts with respect to drug-protein interactions suggest that each small molecule interacts with an average of 6-11 targets. This implies that approved drugs and even discontinued compounds could be repurposed by leveraging their interactions with unintended targets. Therefore, we developed a computational repurposing framework for small molecules, which combines artificial intelligence/machine learning (AI/ML)-based and chemical similarity-based target prediction methods with cross-species transcriptomics information. This repurposing methodology incorporates eight distinct target prediction methods, including three machine learning methods. By using multiple orthogonal methods for a "dataset" composed of 2766 FDA-approved drugs targeting multiple therapeutic target classes, we identified 27,371 off-target interactions involving 2013 protein targets (i.e., an average of around 10 interactions per drug). Relative to the drugs in the dataset, we identified 150,620 structurally similar compounds. The highest number of predicted interactions were for drugs targeting G protein-coupled receptors (GPCRs), enzymes, and kinases with 10,648, 4081, and 3678 interactions, respectively. Notably, 17,283 (63%) of the off-target interactions have been confirmed in vitro. Approximately 4000 interactions had an IC50 of <100 nM for 1105 FDA-approved drugs and 1661 interactions had an IC50 of <10 nM for 696 FDA-approved drugs. Together, the confirmation of numerous predicted interactions and the exploration of tissue-specific expression patterns in human and animal tissues offer insights into potential drug repurposing for new therapeutic applications.

Abstract 2775: A novel immunostimulatory OX40/PD-L1 bivalent bispecific antibody (MEDI1109) for the treatment of patients with cancer

Targeted immunotherapy utilizing agonist antibodies (Ab) to OX40 shows great promise in preclinical mouse models alone or in combination with various therapies including PD1/PD-L1 antagonist Abs. Ab-mediated signaling through OX40 requires higher-order clustering by Fcγ receptors to co-stimulate antitumor-specific T cells and attenuate regulatory T cell (Treg) immunosuppression, leading to antitumor activity. To date, OX40 agonists are well-tolerated but show limited activity alone or in combination with checkpoint blockade in clinical trials. We hypothesize that the antitumor activity of OX40 agonists in patients may be limited by insufficient intratumoral exposure and an inadequate amount of clustering by Fcγ receptors within the tumor microenvironment. To overcome these limitations, we engineered MEDI1109, a bivalent bispecific Ab composed of an OX40 agonist Ab molecularly fused to two single-chain variable fragments derived from a PD-L1 antagonist. The resulting bispecific Ab retained the functional properties of each parent Ab that included binding and agonizing OX40, binding and full blockage of the PD-L1/PD-1 pathway, depletion of OX40+ Tregs and overcoming Treg suppression. Emerging data suggest that the bispecific Ab also drives novel biology including (1) increased OX40 agonism through clustering by either PD-L1 and Fcγ receptors, (2) improved intratumoral exposure through PD-L1 targeting, (3) elimination of PD-L1 positive tumor cells by NK cell mediated antibody-dependent cellular cytotoxicity and (4) enhanced antitumor immunity through concurrent PD-L1/PD-1 blockade on tumor cells and OX40 co-stimulation of antitumor T cells. Intravenous administration of OX40/PD-L1 bispecific Abs to cynomolgus monkeys resulted in the proliferation of peripheral blood CD4+ and CD8+ total memory T-cell populations, and in the reduction of soluble PD-L1 levels in the plasma. These results demonstrate that MEDI1109 is a unique and potent immune modulating agent and may be utilized to enhance antitumor immunity in patients with cancer.

Citation Format: Michael D. Oberst, Srinath Kasturirangan, Clifford Sachs, Catherine Auge, James Moynihan, Raymond Rothstein, James Hair, Francis Neal, Srinivas Mamidi, Shino Hanabuchi, Amanda Watkins, Yanan Zheng, Kim Rosenthal, Daniel J. Freeman, Scott Hammond. A novel immunostimulatory OX40/PD-L1 bivalent bispecific antibody (MEDI1109) for the treatment of patients with cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2775.

[Aplasia cutis congenita and antithyroid drugs during pregnancy: Case series and literature review]

BACKGROUND

Aplasia cutis congenita (ACC) following in utero exposure to antithyroid drugs such as methimazole/carbimazole (MTZ/CMZ) has been reported since 1972. Though currently included in MTZ/CMZ embryopathy, it remains poorly characterized and is little discussed. Having seen two cases within a short period of time, we carried out a literature review and searched the French pharmacovigilance database for notification of cases.

PATIENTS AND METHODS

We performed a search of the literature in the Medline database using the following keywords: "aplasia cutis congenita", "birth skin defects", "pregnancy" and "drug". All articles reporting cases of ACC following in utero exposure to antithyroid drugs were included. All cases of ACC under antithyroid drugs reported to French pharmacovigilance centres were analysed.

RESULTS

Three hundred and sixty-eight articles were retrieved and 31 were analysed, including a further 4, mentioned in selected articles, giving 59 cases of ACC under MTZ/CMZ reported in the literature and having an intrinsic accountability score of plausible or dubious. ACC was typically isolated, single, small in size, and localised on the median scalp area. Exposure occurred in the first weeks of gestation. There were 6 familial cases involving siblings. Ten ACC and MTZ/CMZ cases were reported to pharmacovigilance centres in France.

DISCUSSION

Practitioners should be aware of ACC following MTZ/CMZ exposure in utero, whether it occurs in isolation or not. It is likely a teratogenic effect of MTZ/CMZ enhanced by a genetic predisposition.

[Free fasciocutaneous parascapular flap. Coverage of extensive skin and soft tissue defects]

Coverage of extensive tissue defects is one of the tasks of plastic surgery. For the surgeon there are a series of possibilities differing in safety level and difficulty. With extensively exposed bones, however, there is mostly the indication for free tissue transfer. In the following case a possibility of wound closure of an extensive defect by one single free flap without preconditioning the tissue is demonstrated.

Evaluation of candidate spermatogonial markers ID4 and GPR125 in testes of adult human cadaveric organ donors

The optimal markers for human spermatogonial stem cells (SSCs) are not known. Among the genes recently linked to SSCs in mice and other animals are the basic helix-loop-helix transcription factor ID4 and the orphan G-protein-coupled receptor GPR125. While ID4 and GPR125 are considered putative markers for SSCs, they have not been evaluated for coexpression in human tissue. Furthermore, neither the size nor the character of the human spermatogonial populations that express ID4 and GPR125, respectively, are known. A major barrier to addressing these questions is the availability of healthy adult testis tissue from donors with no known reproductive health problems. To overcome this obstacle, we have employed healthy testicular tissue from a novel set of organ donors (n = 16; aged 17-68 years) who were undergoing post-mortem clinical organ procurement. Using immunolabelling, we found that ID4 and GPR125 are expressed on partially overlapping spermatogonial populations and are more broadly expressed in the normal adult human testis. In addition, we found that expression of ID4 remained stable during ageing. These findings suggest that ID4 and GPR125 could be efficacious for identifying previously unrecognized human spermatogonial subpopulations in conjunction with other putative human stem cell markers, both in younger and older donors.

Development in the cynomolgus macaque following administration of ustekinumab, a human anti-IL-12/23p40 monoclonal antibody, during pregnancy and lactation

BACKGROUND

Ustekinumab is a human monoclonal antibody that binds to the p40 subunit of interleukin (IL) 12 and IL-23 and inhibits their pharmacological activity. To evaluate potential effects of ustekinumab treatment during pregnancy, developmental studies were conducted in cynomolgus macaques.

METHODS

Ustekinumab was tested in two embryo/fetal development (EFD) studies and in a combined EFD/pre and postnatal development (PPND) study. In the EFD studies, pregnant macaques (12/group) were dosed with saline or ustekinumab (9 mg/kg IV, 22.5 mg/kg SC, or 45 mg/kg IV or SC during the period of major organogenesis, gestation day [GD] 20-50). Fetuses were harvested on GD100-102 and examined for any effects on development. In the EFD/PPND study, pregnant macaques were injected with saline or ustekinumab (22.5 or 45 mg/kg SC) from GD20 through lactation day 33. Infants were examined from birth through 6 months of age for morphological and functional development. Potential effects on the immune system were evaluated by immunophenotyping of peripheral blood lymphocytes and immunohistopathology of lymphoid tissues in fetuses and infants and by T-dependent antibody response (TDAR) to KLH and TTX and by DTH response in infants. Ustekinumab concentrations were measured in serum from dams, fetus, and infants and in breast milk.

RESULTS

Ustekinumab treatment produced no maternal toxicity and no toxicity in the fetuses or infants, including no effects on the TDAR or DTH responses. Ustekinumab was present in serum from GD100 fetuses and was present in infant serum through day 120 post-birth. Low levels of ustekinumab were present in breast milk.

CONCLUSIONS

Exposure of macaque fetuses and infants to ustekinumab had no adverse effects on pre- and postnatal development.

Mechanical Properties of the Lobster Cuticle

We present experiments on the mechanical and structural gradients through the cuticle of homarus americanus (lobster). The exocuticle (outer layer) is characterized by a very fine woven structure of the chitin-protein matrix (Bouligand structure) and by a high stiffness (8.5–9.5 GPa). The hardness increases within the exocuticle between the surface region (130 MPa) and the region close to the interface to the endocuticle (270 MPa). In the endocuticle which is characterized by a much coarser twisted plywood (Bouligand) structure both, the stiffness (3–4.5 GPa) and hardness (30–55 MPa) are much smaller than in the exocuticle. The transition in mechanical properties and structure between the exo- and endocuticle is abrupt.

Mesostructure of the Exoskeleton of the Lobster Homarus Americanus

The exoskeleton of the lobsterHomarus americanusis a multiphase bio-composite which consists of a fibrous organic matrix (crystalline α-chitin and various types of non-crystalline proteins) and embedded biominerals (mainly calcite). In this study we present experimental data about the microscopic and mesoscopic structure of this material.

Everolimus in patients with advanced pancreatic neuroendocrine tumors (pNET): Updated results of a randomized, double-blind, placebo-controlled, multicenter phase III trial (RADIANT-3)

158

Background: There is an unmet medical need for effective treatments for patients with advanced pNET. Systemic therapies for advanced pNET are limited both by toxicity and efficacy. Everolimus, an oral mTOR inhibitor, has shown promising antitumor activity in 2 phase II studies, leading to further investigation in the largest phase III randomized controlled trial completed in pNET patients.

Methods: Patients with advanced low- or intermediate-grade pNET were randomly assigned to everolimus 10 mg/d orally + best supportive care (BSC; n = 207) or placebo + BSC (n = 203). Long-acting somatostatin analogs (SSAs) were permitted as BSC during the study. The primary endpoint was progression free survival (PFS). At progression (RECIST), patients could be unblinded and those randomly assigned to placebo were offered open-label everolimus.

Results: Compared with placebo, everolimus reduced the risk of progression by 65% and increased median PFS by more than 6 months, from 4.6 to 11.0 months (HR = 0.35; 95% CI: 0.27-0.45; p < 0.0001), by investigator review (primary endpoint). Median PFS by central review was consistent (HR = 0.34; 95% CI: 0.26 to 0.44; p < 0.001] in favor of everolimus. Eighteen-month PFS estimates were 34% for everolimus (95% CI: 26-43) vs 9% (95% CI: 4-16) for placebo. Everolimus demonstrated a significant PFS benefit across all patient subgroups according to baseline characteristics and prior SSA use. Prior SSA use was 49% in the everolimus arm and 50% in the placebo arm. Updated analyses of the impact of concomitant SSA will be reported. The most common drug-related adverse events were stomatitis, rash, diarrhea, fatigue, and infections (primarily upper respiratory); most were grade 1 or 2. Stomatitis (6.9% vs 0%), anemia (6% vs 0%), and hyperglycemia (5% vs 2%) were the most common grade 3-4 events.

Conclusions: Everolimus significantly prolonged PFS compared with placebo in patients with advanced pNET in this large phase III clinical trial. This benefit was seen across all patient subgroups. Treatment resulted in a significant 6.4-month prolongation in median PFS. Everolimus had an acceptable and predictable safety profile.

[Table: see text]

Carcinogenicity assessments of biotechnology-derived pharmaceuticals: a review of approved molecules and best practice recommendations

An important safety consideration for developing new therapeutics is assessing the potential that the therapy will increase the risk of cancer. For biotherapeutics, traditional two-year rodent bioassays are often not scientifically applicable or feasible. This paper is a collaborative effort of industry toxicologists to review past and current practice regarding carcinogenicity assessments of biotherapeutics and to provide recommendations. Publicly available information on eighty marketed protein biotherapeutics was reviewed. In this review, no assessments related to carcinogenicity or tumor growth promotion were identified for fifty-one of the eighty molecules. For the twenty-nine biotherapeutics in which assessments related to carcinogenicity were identified, various experimental approaches were employed. This review also discusses several key principles to aid in the assessment of carcinogenic potential, including (1) careful consideration of mechanism of action to identify theoretical risks, (2) careful investigation of existing data for indications of proliferative or immunosuppressive potential, and (3) characterization of any proliferative or immunosuppressive signals detected. Traditional two-year carcinogenicity assays should not be considered as the default method for assessing the carcinogenicity potential of biotherapeutics. If experimentation is considered warranted, it should be hypothesis driven and may include a variety of experimental models. Ultimately, it is important that preclinical data provide useful guidance in product labeling.

Influence of microstructure on deformation anisotropy of mineralized cuticle from the lobster Homarus americanus

The exoskeleton of the American lobster Homarus americanus is a hierarchically organized nano-composite material consisting of organic chitin-protein fibers associated with inorganic calcium carbonate. The presence of a well-developed and periodically arranged pore canal system leads to a honeycomb-like structure. The concomitant presence of the twisted plywood arrangement of the mineralized chitin-protein fibers alters the elastic properties, the deformation behavior, and fracture behavior compared to classical honeycomb structures. By performing compression tests in various directions of the cuticle we examined the anisotropic elastic-plastic deformation and fracture behavior of mineralized parts of the exoskeleton. By applying digital image correlation during compression testing, the evolution of the elastic-plastic deformation at the microscopic scale was observed with high resolution and simultaneously global stress and strain data were acquired. Shear tests were performed in order to determine the fracture energy for different shear planes and directions. The investigation of the microstructure after plastic deformation revealed the underlying deformation mechanisms of lobster endocuticle from the claws under different loading conditions. For evaluating the effect of hydration the samples were tested both in the dry and in the wet state.

[Pneumatic tube net conveying systems in the hospital environment]

The primary aim for having recourse to a pneumatic tube net to convey blood samples, is to shorten the turn around time in which transport delay is the major issue: this represents the logical answer to this question, as opposed to point of care testing. It also permits saving in transport personnel. It is of the highest importance of having recourse only to a high quality equipment (robust, reliable) likely to face the heavy workload occurring in a hospital environment, avoiding the use of light structures primarily designed for cash remittance. Implanting such a net in newly constructed structures is generally easy, while connecting the net into old buildings might meet some space limiting difficulties. Detailed prior planning of the network is a major issue for success.

Experimental investigation of the elastic-plastic deformation of mineralized lobster cuticle by digital image correlation

This study presents a novel experimental approach to the characterization of the deformation of a mineralized biological composite using arthropod cuticle as a model material. By performing tensile tests combined with a detailed strain analysis via digital image correlation, the elastic-plastic deformation behavior of the endocuticle of the American lobster Homarus americanus is examined. The test specimens originate from the pincher and crusher claws. For evaluating the effect of moisture on the deformation behavior, the samples are tested both in dry and in wet state. Sample characterization using the digital image correlation method requires a stochastic spot pattern on the sample surface. Digital images are then taken at subsequent deformation stages during the mechanical test. These images are used to calculate the displacement, the displacement gradient, and the strain fields via pattern correlation. The method is applied both, at a global scale to measure with high precision the stress-strain behavior of the bulk cuticle and at a microscopic scale to reveal strain heterogeneity, strain patterning, and strain localization phenomena.

Comparative serum levels and protective activity of parenterally administered cephalosporins in experimental animals

Six cephalosporin antibiotics were administered subcutaneously to mice at a level of 20 mg/kg. The serum levels of each were determined at five time intervals ranging from 5 to 120 min after dosing. Urinary recovery and the presence of active metabolites in mouse urine were determined. The peak serum levels and serum half-lives in mice were found to be positively correlated with the mean effective dose values obtained after lethal challenge with Escherichia coli. The administration of cefazolin and cephanone resulted in the highest serum level and the best protection. Good protection was obtained with cephaloridine despite somewhat lower serum levels. The cephalosporins with the acetoxy side chain (cephalothin, cephapirin, and cephacetrile) showed lower serum levels and the poorest protection. Cefazolin, cephaloridine, and cephalothin serum levels were also determined in dogs, squirrel monkeys, and rabbits. A mixed response was obtained in these species, with cefazolin peak serum levels being highest in rabbits and cephaloridine peak highest in dogs.

Sex-specific fetal weight prediction by ultrasound

OBJECTIVE

To improve sonographic birth-weight prediction by developing fetal gender-specific formulae.

METHODS

This was a retrospective cross-sectional study. Two gender-specific formulae were produced from the data of 527 patients and the data of a further 349 patients were used to evaluate the formulae. Inclusion criteria were a singleton live fetus, gestational age above 25 weeks, birth weight between 1000 g and 4500 g and fetal biometry within 8 days of delivery. Data retrieval was specifically for the purpose of this study.

RESULTS

To yield the best-fit weight formula for each fetal gender we employed step-wise regression analysis based on fractional polynomials with the biometric parameters biparietal diameter (BPD), head circumference (HC), transverse abdominal diameter (TAD), abdominal circumference (AC) and femur length (FL): estimated fetal weight for girls (g) = - 4035.275 + 1.143 x BPD3 + 1159.878 x AC1/2 + 10.079 x FL3 - 81.277 x FL2 [in cm]; estimated fetal weight for boys (g) = 43576.579 + 1913.853 x log10BPD + 0.01323 x HC3 + 55.532 x AC2 - 13602.664 x AC1/2 - 0.721 x AC3 + 2.31 x FL3 [in cm]. These formulae showed superior results compared with those of conventional weight formulae.

CONCLUSION

Gender-related fetal weight calculation allows optimized prediction of fetal weight at birth.

[Performance limiting causes in single use unit systems for the measurement of PO2 and PCO2 in blood]

Having had the opportunity of testing two of the three commercially available single use unit systems (i-STAT and OPTI-1), we have listed a series of performance limiting factors which they share, even though, their detectors being based on different methodologies, they have specific causes of dysfunction. PO2 detectors face the worse problems for different reasons. Temperature control is critical: the cassette or at last the detectors, the internal solution and the specimen have to be heated to 37 C, thermostabilisation to one tenth of degree centigrade is a must. Gas equilibration between liquid phases, the outside ambiance and the plastic material can raise problems: a decrease of the external barometric pressure alters the result, an absence of oxygen buffer capacity can induce modifications of the PO2 in the solutions. The transition of the detectors from a dry to a wet stage can provoke changes of the final result in case of accidental pre-humidication of the cassette. The presence of a single internal solution generates problems linked to a single point calibrage procedure which is a source of variability. The general quality of the cassette can only be evaluated by numerous internal electronic checks: increasing the severity of the controls improves quality but increases the number of rejected cassettes. External quality control through classical procedures are not applicable and finally the quality of the cassettes depends primarily on rigorous manufacturing conditions.

[Analytical performances of the i-STAT portable clinical analyzer for the measurement of PO2 and PCO2]

Aware of some limitations on blood gas results, we performed an extensive evaluation before introducing i-STATs in our hospitals. Three i-STATs were tested in parallel with an ABL-520, on three types of cartridges (EG7, EG6 and EG3), using tonometered whole blood (9 gas levels, n = 720) and aqueous QC solutions (3 levels, n = 600). Reference systems were the theoretical calculated values from gas composition used for tonometry and results given by the ABL-520, respectively. On aqueous controls dispersion intervals reached 10-20 mmHg for both analytes for inter-lot as well as intra-lot data. PO2 values on blood showed marked dispersion: 5 mmHg (CV = 2 to 7%) at clinically critical levels. PCO2 showed several (10%) major outliers: mV recording of the PCO2 electrode allowed to incriminate a pre-humidification problem (due to incorrect shipping conditions). Once outliers have been discarted, there still was a 5 mmHg non negligible residual dispersion (CV = 3 to 5%). i-STAT analytical performances for blood gases which are the analytes whose determination at the bed-side is potentially the most useful, do not match capabilities of classical laboratory instruments. Thus even though the i-STAT approach represents a seducive solution for the STAT problem, for the moment, it's use cannot be recommended in a hospital environment where classical instruments can be made available.

Health care providers' missed opportunities for preventing femicide

BACKGROUND

Homicide of women (femicide) by intimate partners is the most serious form of violence against women. The purpose of this analysis of a larger multisite study was to describe health care use in the year prior to murder of women by their intimate partner in order to identify opportunities for intervention to prevent femicide.

METHODS

A sample of femicide cases was identified from police or medical examiner records. Participants (n = 311) were proxy informants (most often female family members) of victims of intimate partner femicide from 11 U.S. cities. Information about prior domestic abuse and use of health care and other helping agencies for victims and perpetrators was obtained during structured telephone interviews.

RESULTS

Most victims had been abused by their partners (66%) and had used health care agencies for either injury or physical or mental health problems (41%). Among women who had been pregnant during the relationship, 23% were beaten by partners during pregnancy. Among perpetrators with fair or poor physical health, 53% had contact with physicians and 15% with fair or poor mental health had seen a doctor about their mental health problem. Among perpetrators with substance problems, 5.4% had used alcohol treatment programs and 5.7% had used drug treatment programs.

CONCLUSIONS

Frequent contacts with helping agencies by victims and perpetrators represent opportunities for the prevention of femicide by health care providers.

Spatiotemporal self-organization in a surface reaction: from the atomic to the mesoscopic scale

Scanning tunneling microscopy data revealed the atomic processes in propagating reaction fronts that occur in the catalytic oxidation of hydrogen on Pt(111). The fronts were also characterized on mesoscopic length scales with respect to their velocity and width. Simulations on the basis of a reaction-diffusion model reproduce the experimental findings qualitatively well. The quantitative comparison reveals the limitations of this traditional approach to modeling spatiotemporal pattern formation in nonlinear dynamics.

IFCC recommended reference method for the determination of the substance concentration of ionized calcium in undiluted serum, plasma or whole blood

A reference method is described for the determination of the substance concentration of ionized calcium in plasma by which ionized calcium (free or unbound) may be reliably determined on the basis of calibration with aqueous solutions with known concentration of ionized calcium. The composition of the calibration solutions is chosen such that the activity coefficient of the calcium ion is assumed to be identical both in the calibration solutions and in "normal" plasma, i.e. by convention, the ionic strength (Im) is 0.160 mol/kg. The convention is adopted of reporting ionized calcium measurements as concentration expressed as mmol/l. The proposed reference method for ionized calcium measurement in plasma is based on the use of a cell consisting of an external reference electrode with a saturated potassium chloride liquid/liquid junction in combination with a calcium ion-selective membrane electrode of defined construction and performance. Procedures for using the reference cell and a protocol for sample measurement are described. The preparation of the calibration solutions to be used are described in detail in Appendix A, secondary calibration solutions and check standards in Appendix B, and reference cell vessel design in Appendix C.

Recommendations for measurement of and conventions for reporting sodium and potassium by ion-selective electrodes in undiluted serum, plasma or whole blood. International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). IFCC Scientific Division Working Group on Selective Electrodes

Ion-selective electrodes (ISEs) respond to ion-activity and therefore do not sense substance concentration directly. However, it is recognized that sodium and potassium in plasma will continue to be expressed for clinical purposes in terms of substance concentration (mmol/l). A convention is proposed whereby for routine clinical purposes results of ISE measurements of sodium and potassium in undiluted plasma should be reported in terms of substance concentration (mmol/l). In specimens with normal concentrations of plasma water, total CO2, lipids, protein and pH, the values will concur with the total substance concentration as determined for example by flame atomic emission spectrometry (FAES) or ISE measurements on diluted samples. In specimens with abnormal concentrations of plasma water, the results will differ. However, under these circumstances, measurements of sodium and potassium by ISE in the undiluted sample will more appropriately reflect the activity of sodium and potassium and are therefore clinically more relevant than the determination in diluted samples. Detailed recommendations are made about practical procedures to achieve this. The recommended name for this quantity is the substance concentration of ionized sodium or ionized potassium in plasma, as opposed to total sodium or total potassium determined by, e.g. FAES, or ISE measurements on diluted samples.

Pulse oximetry as a fifth vital sign in emergency geriatric assessment

OBJECTIVE

To determine the utility of pulse oximetry as a routine fifth vital sign in emergency geriatric assessment.

METHODS

Prospective study using pulse oximetry to measure O2 saturation in geriatric patients presenting to ED triage. Saturation values were disclosed to clinicians only after they had completed medical evaluations and were ready to release or admit each patient. The authors measured changes in medical management and diagnoses initiated after the disclosure of pulse oximetry values. The study included 1,963 consecutive adults aged > or = 65 years presenting to triage at a university ED. Measurements included changes in select diagnostic tests: chest radiography, complete blood count (CBC), spirometry, arterial blood gases (ABGs), pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, and supplemental O2; and hospital admission and final diagnoses that occurred after complete ED evaluation when physicians were informed of triage pulse oximetry values.

RESULTS

397 (20.2%) geriatric patients had triage pulse oximetry values <95%. Physicians ordered repeat oximetry for 51 patients, additional chest radiography for 23, CBC for 16, ABGs for 15, spirometry for 5, and ventilation-perfusion scans for none. Physicians ordered 49 new therapies for 44 patients, including antibiotics for 14, supplemental O2 for 29, and beta-agonists for 6. Nine patients initially scheduled for ED release were subsequently admitted to the hospital. Physicians changed or added diagnoses for 27 patients.

CONCLUSIONS

Using pulse oximetry as a routine fifth vital sign resulted in important changes in the diagnoses and treatments of a small proportion of emergency geriatric patients.

Nitric oxide and the renin angiotensin system: contributions to blood pressure in the young rat

The present study was designed to investigate the effects of chronic administration of the arginine analogue L-Name (50 mg/kg body weight), the angiotensin converting enzyme inhibitor, perindopril (2 mg/kg body weight), and perindopril (2 mg/kg) plus L-Name (50 mg/kg) on blood pressure, plasma renin activity, plasma angiotensinogen, and hepatic angiotensinogen mRNA levels in young and adult rats. The drugs were given daily from birth to day 21 to puppies and for 15 days to adults. Analytical procedures were performed on day 21 for the puppies and at 10 weeks for the adults. In puppies, blood pressure did not change with L-Name, it decreased to 45% of control values (P < 0.001) with perindopril, and decreased to 77% of control values (P < 0.05) with perindopril plus L-Name. In adults, blood pressure increased to 129% of control values (P < 0.02) with L-Name, decreased to 80% of control values (P < 0.05) with perindopril, and did not change with perindopril plus L-Name. Compared with controls, plasma renin activity was unchanged in puppies and adults with L-Name, undetectable in puppies and slightly increased in adults with perindopril, undetectable in puppies and slightly decreased in adults with perindopril plus L-Name. With L-Name, angiotensinogen mRNA levels were unchanged in puppies and slightly increased in adults, while plasma angiotensinogen levels were decreased (P < 0.05) in puppies and increased (P < 0.01) in adults; with perindopril, angiotensinogen mRNA levels were unchanged in puppies and slightly decreased in adults, while plasma angiotensinogen levels were undetectable in puppies and decreased (P < 0.05) in adults; with perindopril plus L-Name, angiotensinogen mRNA levels were unchanged in puppies while plasma angiotensinogen levels were undetectable in puppies and decreased (P < 0.01) in adults. This study suggests that during the early postnatal period (1) nitric oxide does not exert a basal vasodilator tone but contributes to the hypotensive state induced by perindopril, (2) angiotensin II is essential to maintain blood pressure, (3) and angiotensinogen mRNA levels are not influenced by nitric oxide or angiotensin II.

The European Register for Clinical Chemists. (European Communities Confederation of Clinical Chemistry, Working Group on Registration)

To ensure freedom of movement in the European Union, a limited number of professions is regulated by a so-called Sectorial Directive; all other disciplines, including clinical chemistry, fall under a General Directive. However, clinical chemists in the EU wish their specialty to be more specifically regulated; this means that common standards of education, training, experience and compliance with continuing professional developments must be guaranteed. Therefore, the European Communities Confederation of Clinical Chemistry (EC4) is about to implement the European Register for clinical chemists, and has composed a guide to this Register. The document describes the conditions for entry to specialty training, the minimum standards for registration (university education and postgraduate vocational training with a minimum total of eight years), the competencies of those qualifying for registration, and the operation of the register. Registration guarantees professional and managerial competencies; the title conferred is "European Clinical Chemist". EC4 recognises the existing national registers as far as they are based on the minimal requirements as indicated. An EC4 Register Commission (EC4RC) will maintain and control the European Register, supported by National Clinical Chemistry Registration Committees (NCCRC). An NCCRC controls the quality of the education in each country and assesses candidates. An individual (EU citizen or non-EU citizen trained in an EU country) applies privately for the European Register to EC4RC and, where applicable, the application is accompanied by a document from the NCCRC of the country of registration, stating that the applicant has the necessary qualifications. For EU citizens trained outside the EU the final decision is with EC4RC; non-EU citizens not trained in an EU country are not eligible for registration. Registration is renewed once every five years.

Pulse oximetry as a fifth pediatric vital sign

PURPOSE

To determine the utility of pulse oximetry as a routine fifth vital sign in acute pediatric assessment.

DESIGN

Prospective study using pulse oximetry to measure oxygen saturation in children presenting to emergency department triage. Saturation values were disclosed to clinicians only after they had completed medical evaluations and were ready to discharge or admit each child. We measured changes in medical treatment and diagnoses initiated after the disclosure of pulse oximetry values.

SETTING AND PARTICIPANTS

The study included 2127 consecutive children presenting to triage at a university emergency department.

MEASUREMENTS

Changes in select diagnostic tests: chest radiography, complete blood count, spirometry, arterial blood gases, pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, supplemental oxygen; and hospital admission and final diagnoses that occurred after disclosure of triage pulse oximetry values.

RESULTS

Of 305 children having triage pulse oximetry values less than 95%, physicians ordered second oximetry for 49, additional chest radiography for 16, complete blood counts for 7, arterial blood gas measurements for 4, spirometry for 2, and ventilation-perfusion scans for 2. Physicians ordered 39 new therapies for 33 patients, including antibiotics for 15, supplemental oxygen for 11, and beta-agonists for 8. Five patients initially scheduled for hospital discharge were subsequently admitted. Physicians changed or added diagnoses in 25 patients.

CONCLUSIONS

Using pulse oximetry as a routine fifth vital sign resulted in important changes in the treatment of a small proportion of pediatric patients.

A comparison of pulse oximetry and respiratory rate in patient screening

OBJECTIVE

To examine how well respiratory rate correlates with arterial oxygen saturation status as measured by pulse oximetry, and determine whether respiratory rate measurements detect oxygen desaturation reliably.

METHODS

Respiratory rate (RR) and oxygen saturation (SaO2) were measured prospectively on 12,096 consecutive adult emergency department triage patients at a university medical center. Respiratory rate was measured by counting ausculated breath sounds for 1 min. Pulse oximetry was used to measure SaO2. Measurements were analysed by age (with one group for 18-19 year olds, groups for every 10 yr from age 20 to age 60, and groups for every 5 yr for subsequent ages). Pearson correlation coefficients were calculated for each age group as well as the weighted average coefficient. Cases having oxygen saturation below 90% were examined to determine how frequently they exhibited increased RR (increased RRs were defined as any rate in the upper five percentile by age.

RESULTS

Correlation coefficients ranged from 0.379 to -0.465 with a weighted mean of -0.160. Coefficients for ages 18 through 70 years (representing 10,740 patients) all had magnitude < 0.252. Overall, only 33% of subjects with oxygen saturation below 90% exhibited increased RR.

CONCLUSIONS

Respiratory rate measurements correlate poorly with oxygen saturation measurements and do not screen reliably for desaturation. Patients with low SaO2 do not usually exhibit increased RR. Similarly, increased RR is unlikely to reflect desaturation.

Evaluation of syringes for ionized calcium measurements

Commercially available ready to use syringes (Radiometer, Sarstedt, Ciba-Corning and Portex), containing heparinate as an anticoagulant have been tested to evaluate the magnitude of induced preanalytical errors. Tonometered serum pools adjusted to four Ca2+ concentrations were sampled anaerobically.

MEASUREMENTS

Ca2+ and pH (ICA2 with 3 digits, Radiometer Medical A/S, Denmark; Heparin: anti-Xa factor activity on a chromogenic substrate. Results were expressed as means of 10 measurements and as percentages of the reference values. Sarstedt syringes, (Li-heparinate), yielded a negative bias (-3%). However for 0.5 or 1 mL samples the bias reached -4% to -6%. Radiometer syringes (QS50 and QS90; calcium titrated heparinate) demonstrated biases below -2%. The bias in the Ciba-Corning (Gas-Lyte) syringe was below 2%. Portex (Pulsator) syringes showed biases above +4% even for nominal sampling volumes. All syringes (except Pulsator) released anticoagulant amounts corresponding to the expected values. Radiometer and Ciba-Corning were the only recommendable devices.

Effect of routine emergency department triage pulse oximetry screening on medical management

PURPOSE

To determine the utility of routine triage pulse oximetry screening in emergency department (ED) patients.

DESIGN

Prospective study using pulse oximetry to measure oxygen saturation of ED patients at triage. Saturation values were disclosed to physicians only after they completed medical evaluations and were ready to discharge or admit each patient. We measured changes in medical management initiated after disclosure of pulse oximetry values.

SETTING AND PARTICIPANTS

The study included 14,059 consecutive patients presenting to triage at a university ED.

MEASUREMENTS

Changes in select diagnostic tests: chest radiography, CBC count, spirometry, arterial blood gases, pulse oximetry, and ventilation-perfusion scans; treatments: antibiotics, beta-agonists, supplemental oxygen; and hospital admission and final diagnoses that occurred after disclosure of triage pulse oximetry values.

RESULTS

Of 1,175 patients having triage pulse oximetry values less than 95%, physicians ordered repeat pulse oximetry on 159 (13.5%), additional chest radiography on 5.4%, CBC count on 3.1%, arterial blood gases on 2.9%, spirometry on 0.9%, and ventilation-perfusion scans on 0.3%. Physicians ordered 178 new therapies on 134 patients (11.4%), including supplemental oxygen for 6.5%, antibiotics for 3.9%, and beta-agonists for 1.8%. Thirty-five patients (3.0%) initially scheduled for hospital discharge were subsequently admitted. Physicians changed or added diagnoses in 77 patients (6.6%).

CONCLUSIONS

Providing physicians with routine triage pulse oximetry measurements resulted in significant changes in medical treatment of these patients.

Fetal urinary insulin-like growth factor I and binding protein 3 in bilateral obstructive uropathies

Fetal urinary concentrations of insulin-like growth factor I (UIGF-I) and binding protein 3 (UIGFBP-3) were determined in patients with prenatal diagnosis of bilateral obstructive uropathy. Patients were retrospectively assigned to three groups, on the basis of outcome: group 1, termination of pregnancies (n = 11) with sonographic evidence of severe oligohydramnios or renal dysplasia, confirmed at histological examination; group 2, patients (n = 10) with postnatal plasma creatinine > 50 mumol/l at the age of 1 year (1 yr-pCreat); and group 3, patients (n = 16) with 1 yr-pCreat < or = mumol/l. The results show a significant increase in UIGF-I and UIGFBP-3 in groups 1 (18,159 +/- 9083 pg/ml; 2657 +/- 669 ng/ml) and 2 (1574 +/- 847 pg/ml; 176 +/- 50 ng/ml) in comparison with group 3 (35 +/- 6 pg/ml; 21 +/- 2 ng/ml). UIGF-I and UIGFBP-3 were significantly correlated with postnatal plasma creatinine, and were both sensitive (90 per cent; 80 per cent) and specific (88 per cent; 88 per cent) for prediction of elevated 1 yr-pCreat (> 50 mumol/l). Fetal urinary IGF-I and IGFBP-3 are increased in severe fetal bilateral obstructive uropathy, possibly reflecting tubular dysfunction or/and increased synthesis consequent upon fetal kidney injury. Their predictive value for postnatal renal function needs further assessment.

Deleterious effects of inhibition of the renin-angiotensin system in neonatal rats

The angiotensin I converting enzyme inhibitor (ACEI) perindopril (2 mg/kg body weight), the peripheral vasodilator dihydralazine (DHL) (25 mg/kg body weight) or distilled water was given daily from birth to day 14 to neonatal rats. Blood pressure, plasma creatinine, plasma renin activity (PRA), substrate (PRS) and concentration (PRC) and renin content of kidney tissue sections were evaluated on days 14 and 28. By day 14, a high mortality in the ACEI group was observed. ACEI, but not DHL, led to a significant fall (P < 0.01) in blood pressure, 57 +/- 11 versus 89 +/- 25 in the DHL group and 103 +/- 24 mmHg in controls, and to a dramatic increase in plasma creatinine. PRA and PRS were undetectable in ACEI-treated rats; in contrast, PRC and renal staining with anti-renin antibody were significantly increased in ACEI rats. On day 28, the blood pressure was normal in all groups and plasma creatinine returned to the normal range in ACEI rats. PRA, PRS and PRC were not significantly different in the ACEI group and controls. These results suggest that the renin-angiotensin system (RAS) plays a major postnatal role in the neonatal rat. Inhibition of the RAS during the first 2 weeks of life leads to high mortality, severe hypotension, reversible renal failure and a defect in circulating angiotensinogen.