Identification and Mechanistic Investigation of Drug-Drug Interactions Associated With Myopathy: A Translational Approach

Myopathy is a group of muscle diseases that can be induced or exacerbated by drug–drug interactions (DDIs). We sought to identify clinically important myopathic DDIs and elucidate their underlying mechanisms. Five DDIs were found to increase the risk of myopathy based on analysis of observational data from the Indiana Network of Patient Care. Loratadine interacted with simvastatin (relative risk 95% confidence interval [CI] = [1.39, 2.06]), alprazolam (1.50, 2.31), ropinirole (2.06, 5.00), and omeprazole (1.15, 1.38). Promethazine interacted with tegaserod (1.94, 4.64). In vitro investigation showed that these DDIs were unlikely to result from inhibition of drug metabolism by CYP450 enzymes or from inhibition of hepatic uptake via the membrane transporter OATP1B1/1B3. However, we did observe in vitro synergistic myotoxicity of simvastatin and desloratadine, suggesting a role in loratadine–simvastatin interaction. This interaction was epidemiologically confirmed (odds ratio 95% CI = [2.02, 3.65]) using the data from the US Food and Drug Administration Adverse Event Reporting System.

Identification and characterization of a novel HLA-B hybrid allele, B*08:132 with Next Generation Sequencing

The new allele is a hybrid between B*08:01:01 and B*42:01:01.

16(th) IHIW : review of HLA typing by NGS

Human leucocyte antigen (HLA) genes play an important role in the success of organ transplantation and are associated with autoimmune and infectious diseases. Current DNA-based genotyping methods, including Sanger sequence-based typing (SSBT), have identified a high degree of polymorphism. This level of polymorphism makes high-resolution HLA genotyping challenging, resulting in ambiguous typing results due to an inability to resolve phase and/or defining polymorphisms lying outside the region amplified. Next-generation sequencing (NGS) may resolve the issue through the combination of clonal amplification, which provides phase information, and the ability to sequence larger regions of genes, including introns, without the additional effort or cost associated with current methods. The NGS HLA sequencing project of the 16IHIW aimed to discuss the different approaches to (i) template preparation including short- and long-range PCR amplicons, exome capture and whole genome; (ii) sequencing platforms, including GS 454 FLX, Ion Torrent PGM, Illumina MiSeq/HiSeq and Pacific Biosciences SMRT; (iii) data analysis, specifically allele-calling software. The pilot studies presented at the workshop demonstrated that although individual sequencers have very different performance characteristics, all produced sequence data suitable for the resolution of HLA genotyping ambiguities. The developments presented at this workshop clearly highlight the potential benefits of NGS in the HLA laboratory.

Design of a medication reconciliation application: facilitating clinician-focused decision making with data from multiple sources

BACKGROUND

Medication reconciliation is an essential, but resource-intensive process without a "gold standard" to measure medication adherence. Medication reconciliation applications that focus on facilitating clinicians' decision-making are needed. Since no single available source of medication information is adequate, combining data sources may improve usefulness and outcomes.

OBJECTIVES

We aimed to design a medication reconciliation application that could incorporate multiple data sources and convey information about patients' adherence to prescribed medications. We discuss design decisions integral to developing medication reconciliation applications for the electronic health record. The discussion is relevant for health IT developers, clinical providers, administrators, policy makers, and patients. Three hypotheses drove our design of this application: 1) Medication information comes from a variety of sources, each having benefits and limitations; 2) improvements in patient safety can result from reducing the cognitive burden and time required to identify medication changes; 3) a well-designed user interface can facilitate clinicians' understanding and clinical decision making.

METHODS

Relying on evidence about interface design and medication reconciliation, an application for the electronic health record at an academic medical center in the U.S. was designed. Multiple decisions that considered the availability, value, and display of the medication data are explored: Information from different sources; interval changes in medications; the sorting of information; and the user interface.

RESULTS

THE PROTOTYPE MEDICATION RECONCILIATION APPLICATION DESIGN REFLECTS THE VISUAL ORGANIZATION, CATEGORIZATION, MODALITY OF INTERACTIONS, AND PRESENTATION OF MEDICATION INFORMATION FROM THREE DATA SOURCES: patient, electronic health record, and pharmacy.

CONCLUSIONS

A new medication reconciliation user interface displays information from multiple sources, indicates discrepancies among sources, displays information about adherence, and sorts the medication list in a useful display for clinical decision making. Gathering, verifying, and updating medication data are resource-intensive processes. The outcomes of integrating, interpreting, and presenting medication information from multiple sources remain to be studied.

Vulvodynia, a step-wise therapeutic prospective cohort study

Vulvodynia is characterised by the presence of vulval allodynia (pain evoked by non-painful stimuli) and vulval dysaesthesias (burning, soreness, rawness, stinging and irritation). We assessed a protocol for the evaluation and management of vulvodynia. The protocol was based on the most recent evidence available. We began a simple evaluation and proceeded to an aggressive one. From the cohort of 74 patients, 69 patients (93.2%) were adherent to the protocol. A total of 25 patients (36.3%) improved after antibiotic therapy: 14 patients (20.4%) had a positive fungal culture and 11 patients (15.9%) had a positive bacterial culture; none with a positive viral culture. Eight patients (11.6%) improved with dietary modification. Ten patients (14.5%) benefitted from tricyclic medications; 13 patients (18.8%) improved after gabapentin therapy; 13 patients (18.8%) did not show improvement of their condition. Some 56 patients (81.2%) manifested an improvement of their symptoms, which allowed them to achieve painless sexual intercourse.

Vibrotactile threshold measurement for detecting peripheral neuropathy: defining variability and a normal range for clinical and research use

AIMS/HYPOTHESIS

We aimed to define normal ranges for vibration sense as measured by vibratory perception thresholds (VPTs) using biothesiometry.

METHODS

We performed biothesiometry in a community-dwelling sample of 901 people aged 55 to 85 years who did not have diabetes. We quantitated the variation between repeat measures using analysis of variance and Bland-Altman plots. We also plotted the age- and sex-specific reference ranges.

RESULTS

We found small but statistically significant differences between repeat measures using the ascending and descending method of limits. Statistically higher vibration thresholds were noted on the right arm and leg compared with the left. Significantly higher vibration thresholds were also seen in men vs women for both lower limbs. We also defined sex-specific reference intervals (normal ranges) for biothesiometry for older persons and quantitated the increase in vibration threshold with increasing age.

CONCLUSIONS/INTERPRETATION

For reliability, it may be sufficient to obtain the average of two ascending measures separated by at least 1 min in just the right hand or right foot, since this is usually the one with the higher threshold. Although identical reference ranges can be used for men and women for the upper limb, there are significant differences in the lower limbs. The major determinant of VPT is age: we have established age-specific norms for VPT testing for adults between 55 and 85 years of age.

Apoptosis staining in cultured pseudoachondroplasia chondrocytes

Pseudoachondroplasia (PSACH) is a skeletal dysplasia caused by a mutation in cartilage oligomeric matrix protein (COMP), a glycoprotein of normal cartilage matrix. PSACH chondrocytes have a distinctive phenotype with enlarged rER cisternae containing COMP, aggrecan, type IX collagen, and chaperone proteins. Ultrastructural studies suggested that this accumulation compromises cell function, hastening cell death, and consequently reducing the number of cells in the growth plate contributing to linear bone growth. Using the alginate bead system, we cultured control and PSACH chondrocytes for twenty weeks and one year to determine the effect of the mutation on size and number of cartilage nodules; and the presence of apoptotic cell death (TUNEL assay). At 20 weeks, beads containing PSACH or control chondrocytes did not differ in size and number of cartilage nodules or number of TUNEL-positive cells. After one year, nodule number, size and percent cartilage per bead were significantly less in PSACH nodules, and the number of cells staining positive for apoptosis was significantly greater than in controls (71.8% vs. 44.6%). The increase in apoptosis in PSACH nodules correlates with a decrease in growth of cartilage, supporting our hypothesis that death of damaged cells contributes to the growth plate defects in PSACH.

Analysis of thirteen populations of black cohosh for formononetin

Black cohosh (Actaea racemosa L. syn. Cimicifuga racemosa (L.) Nutt.), a North American perennial plant, is a promising natural alternative to hormone replacement therapy for treating menopausal symptoms, but the mechanism of action is not understood. The clinical actions of this plant have been attributed to the isoflavonone formononetin since 1985, when its presence was reported in a black cohosh extract. Others have since looked for formononetin, but have not detected it. We looked for formononetin in extracts of black cohosh roots and rhizomes collected in thirteen locations in the eastern United States, including Maryland, New Jersey, New York, North Carolina, Pennsylvania, Virginia, and Tennessee. The rhizome samples were extracted using 80% methanol, and the extracts were partially purified using solid-phase extraction to concentrate any isoflavonoids that might be present. We tested for formononetin in these partially purified samples using thin-layer chromatography and high-performance liquid chromatography with a photodiode array detector and a mass spectrometer. Formononetin was not detected in any of the thirteen plant populations examined. Remifemin, a German product now on the United States market, and CimiPure, a commercially available black cohosh rhizome extract, were also analyzed. We did not detect formononetin, or ononin (formononetin-7-glucoside), in any sample tested by the above-mentioned chemical analyses. Therefore, the clinically observed estrogen-like actions of black cohosh, such as reduction of hot flashes, are likely due to a compound, or combination of compounds, other than formononetin.

SEM visualization of glycosylated surface molecules using lectin-coated microspheres

There are several techniques currently used to localize glycosylated surface molecules by scanning electron microscopy (Grinnell, 1980; Molday, 1976; Linthicum and Sell, 1975; Nicolson, 1974; Lo Buglio, et al, 1972). A simple and rapid method, using a modification of Grinnell's technique is reported here. Essentially, microspheres coated with Concavalin A are used to bind to glycosylated regions of the palatal shelf epithelium and are visualized in the scanning electron microscope (SEM).

Effect of chronic centrifugation on mouse breeding pairs and their offspring

Fetuses of chronically centrifuged mice are smaller than 1g fetuses, and have reduced areas of long bone ossification. Fewer pregnancies occurred in centrifuged mice. In this study, exposure of chronically centrifuged females to male bedding 48 hours prior to mating induced estrus as determined by vaginal smears. Females were paired with males on the centrifuge or at 1g, and were sacrificed at 18 days gestation. Fetuses were weighed, measured, and stained with alizarin red and methylene blue. This new mating method increased centrifuge pregnancies, but not to control levels. There were no pregnancies at 3.5 g. Weights and crown rump lengths of centrifuged 18-day fetuses were less than those of controls, significantly so at 2.6 and 2.9g. There was no effect on litter size, number of resorptions per litter or male/female ratio. Bones of centrifuged fetuses were found to be smaller and shaped differently from controls. Effects were mitigated by matings with 1g males. Results confirm our previous reports of decreased fetal size and areas of ossification in hypergravity, and demonstrate a reliable method for providing timed-pregnant mice in hyper-g conditions.

Acceleration of fusion in mouse palates by in vitro exposure to excess G

Palatal shelves from 13- and 14-day mouse embryos were excised and cultured in contiguous pairs. Experimental cultures were exposed to 2.6 G in a culture centrifuge; controls were in the same incubator. After 24 hours, palates were prepared for light or electron microscopy. Scoring of paraffin sections according to the stage of fusion seen in the medial epithelial edges (MEE) showed that palates exposed to excess G were in more advanced stages of fusion than were controls. Ultrastructurally, control MEE had tightly apposed cell membranes and numerous desmosomes; in centrifuged MEE, desmosomes had been removed and there was much intercellular space. Nuclear membranes were intact in control MEE, but showed marked deterioration in MEE of centrifuged palates. Few lysosomes and no necrosis were seen in control MEE; centrifuged MEE had numerous lysosomes as well as necrotic cells. Basal lamina were intact in controls, but interrupted in centrifuged palates. The results confirm the hypothesis that gravitational increases speed up the differentiative process.

Crystallization and preliminary X-ray diffraction data of the complex of recombinant tick anticoagulant peptide (rTAP) and bovine factor Xa

The complex of bovine factor Xa and recombinant tick anticoagulant peptide (rTAP) was crystallized in two different crystal forms using polyethylene glycol as a precipitant. Form I belongs to space group P42212 with unit-cell dimensions a = b = 133.1, c = 68.8 A. It contains one complex per asymmetric unit and diffracts to 3.0 A resolution. Form II belongs to P41212 (or P43212) with dimensions a = b = 126.5, c = 146.7 A; it contains two complexes per asymmetric unit and diffracts to 2.5 A. The crystals of both forms consist of factor Xa (MW = 45.3 kDa) and rTAP (MW = 6.7 kDa).

Unexpected binding mode of tick anticoagulant peptide complexed to bovine factor Xa

The structure of recombinant tick anticoagulant peptide (rTAP) complexed to bovine factor Xa at 3.0 A resolution reveals the structural basis for the specificity and the high affinity of rTAP. Three N-terminal residues, Tyr501, Asn502 and Arg503, play a critical role in the complex formation as suggested by earlier mutagenic studies and the ornithodorin-thrombin complex. Unexpectedly, the side-chain of Tyr501 is located in the S1 pocket, although factor Xa favors arginine as a P1 residue. Arg503 is located at the aryl binding pocket and forms a salt-bridge with Glu97 of factor Xa. The autolysis loop, which is disordered in the uninhibited factor Xa structure, is involved in the formation of the complex as a part of the secondary binding site. The C-terminal helix of rTAP interacts with factor Xa as a secondary binding determinant. The N-terminal residues of rTAP reorganize during the formation of the factor Xa-rTAP complex from the conformation found in the solution into an extended conformation. The presence of the secondary binding site confirms the proposed two-step kinetic mechanism based on the results of a mutagenesis study.

Nurses' attitudes toward organ donation: an Australian perspective

Australia's rate of organ donation, which has shown a continuing downward trend, is among the lowest in the developed world. Research has demonstrated that nurses' attitudes and behaviors are important functions in organ donation, particularly retrieval. This study investigated the attitudes and knowledge levels about organ donation of paediatric nurses in a large metropolitan children's hospital and nurses in two rural hospitals. The results highlight the role that critical care nurses and advanced practice nurses need to play in improving levels of organ donation.

Chondrogenesis in aggregates of embryonic limb cells grown in a rotating wall vessel

Previous studies in this lab have shown that chondrogenesis is affected in growth plates of rats exposed to microgravity, and in micromass cultures of embryonic limb mesenchyme differentiating in space. In order to provide a three dimensional aspect not seen in the micromass system, and a tissue homogeneity not possible with explants of limb or limb elements, and to alleviate certain difficulties regarding crew time and stowage, we began culturing embryonic limb cells in Rotating Wall Vessels (RWV). First, these cells were attached to beads, and grown for up to 65 days in a type of RWV known as STLV at the Johnson Space Center. During this time, the cells and beads aggregated and the aggregates continued to increase in size, and differentiated into Alcian blue staining chondrocytes. Because our intent was to use these aggregates for implanting into bony defects in addition to their use in studies of chondrogenic regulation at 1g and microgravity, aggregates of these cells without beads were grown in the commercially available version of the STLV, and their ability to ossify when subcutaneously implanted assessed.

Clinorotation inhibits chondrogenesis in micromass cultures of embryonic mouse limb cells

Studies of the response of mammalian chondrocytes to gravitational changes in vivo, in organ culture, and in cell culture show that chondrogenesis is reduced in microgravity or by unloading, and increased by low levels of excess g. To investigate the cellular responses to microgravity using a ground based model, micromass cultures were exposed to simulated weightlessness on two clinostats. For rotation on the large clinostat, cultures were set up in Rose chambers, and cells were videotaped and photographed at several time periods after rotation began. For the smaller clinostat, cultures were set up in T-flasks, and two axes of rotation for clinostated cultures were used. Stationary controls [+1 g, -1 g (upside-down), and sideways] as well as rotation controls were employed. Rotation rate was 30 rpm for both clinostatted cultures and rotation controls. Chondrocyte differentiation was assessed by cartilage specific alcian blue staining. Significantly fewer alcian blue stained nodules were present in clinostatted cultures than in stationary controls or rotation controls. Nodules that did not stain with alcian blue, probably due to unsulfated matrix were present in all cultures. The number of nodules in sideways controls was greater than in any other culture (108% of +1 g controls), probably due to ongoing stimulus of the cell via cytoskeletal components. The results show that chondrocytes in culture respond to changes in the gravity vector in a predictable manner, and that carefully controlled clinostat studies can be useful adjuncts to and predictors for spaceflight experiments.

Pregnancy and cirrhosis: management of hematemesis by Warren shunt during third trimester gestation

Considerable pathophysiologic changes accompany cirrhosis. Elevation of portal venous pressure predisposes to esophageal varices and hematemesis. The physiologic changes associated with pregnancy may exacerbate these conditions. Medical management of cirrhosis-associated problems may fail, necessitating surgical intervention. The anesthetic management of a pregnant cirrhotic patient for a Warren shunt is complicated by concerns for pre-existing hepatic dysfunction and pregnancy-induced physiologic changes as well as fetal well-being. The management of such a case is reviewed and relevant pathophysiology discussed.

Elbow flexion test in the normal population

The elbow flexion test was investigated in 204 elbows in 102 normal volunteers. The effects of various wrist and shoulder positions were also studied. In 20 elbows in 15 persons (10%) flexion tests were positive with the wrist and shoulder in neutral position. In 27 elbows in 20 persons (13%) tests were positive with wrist extension and shoulder abduction.

Vasoactive intestinal peptide and nerve regeneration

The role of vasoactive intestinal peptide (V.I.P.) in nerve regeneration was investigated by assessing the changes in immunoreactive V.I.P. levels in rat sciatic nerves following injury and repair. 60 rats were divided into three surgical groups and one control group: In group I (primary repair), sciatic nerves were divided and immediately repaired; in group II (secondary repair), sciatic nerves were divided and repaired two weeks later; in group III (no repair), sciatic nerves were divided and not repaired; and in group IV (controls), sciatic nerves were exposed but not divided. Animals were sacrificed at three days and at weekly intervals. Their sciatic nerves were extracted and assayed for V.I.P. concentrations by a specific radioimmunoassay. The mean V.I.P. concentration varied between 22 and 46 pg./mg. protein in the control nerves and between 60 and 529 pg./mg. protein in all other groups. In the three surgical groups the levels were significantly higher in proximal than in distal stumps. Following nerve injury, there was an increase in V.I.P. concentration in the injured and repaired areas. This increase was greater in injured non-repaired areas and was highest in the first 48 hours, but continued during regeneration. The accumulation of V.I.P. in divided nerves occurred in response to nerve injury.

Using comparative clinical information to understand practice patterns and affect organizational change

The University Hospital Consortium is collecting clinical, administrative and financial data from its members to develop a Clinical Information Network. The value of this collective data lies in how comparative information about peer hospitals and physicians in the same specialty can be used to influence practice. The raw data from each hospital is analyzed, classified, normalized and stored in a data repository which is easily accessible. This data becomes information when it is presented in a variety of ways, and is supported by a knowledge-base of health care rules. The "drilling down" technique to progressive levels of detail serves the needs of all levels in the organization--executives, managers, and analysts. The system combines the power of a mainframe for the data repository with the ease of use of a PC-based workstation. With an open-ended approach, the users can ask a variety of questions of the data, as well as perform statistical analysis, create graphical presentations and generate explanations of the analysis techniques.

Fibrochondrogenesis in male twins at 24 weeks gestation

Fibrochondrogenesis is a rare lethal chondrodysplasia. Only 5 cases have been reported. We report on a pair of affected twins diagnosed at 24 weeks of gestation. Occurrence in sibs and consanguinity in the parents in a previous report support autosomal recessive transmission.

Effect of sleep state and position on the incidence of obstructive and central apnea in infants

Sixty-four infants with a history of apnea were studied to determine the effects of sleeping position and sleep state (rapid eye movement [REM]) v (non-rapid eye movement [NREM]) on the occurrence of central and obstructive apneas. All-night polysomnographic studies were conducted on each infant, and the spontaneous occurrence of central and obstructive apneic events was determined in the prone, supine, and side positions. Sleeping position did not significantly affect the rate or duration of central or obstructive apneas. Furthermore, neither central nor obstructive apneic episodes were significantly altered by sleep state. These data suggest that, in spite of an ostensible predisposition to upper airway obstruction in the supine position and during rapid eye movement sleep, neither sleeping position nor sleep state appears to affect the rate of duration of apneic events.

Interaction of anti-kojibiose antibody with the lipoteichoic acids from Streptococcus faecalis and Streptococcus faecium

Antisera prepared in rabbits by immunization with p-aminophenyl beta-kojibioside conjugated to bovine serum albumin (antikojibiose sera), readily agglutinated whole cells of Streptococcus faecalis or Streptococcus faecium, and showed specific reactions with the lipoteichoic acids (LTAs) of these streptococci by passive hemagglutination, microscale enzyme-linked immunosorbent assay, and crossed immunoelectrophoresis. The interaction of the antikojibiose sera with the LTAs was inhibited best by kojibiose [alpha-D-glucopyranosyl-(1----2)-D-glucose], somewhat less by the dextran from which the kojibiose was prepared, and not measurably by maltose [alpha-D-glucopyranosyl-(1----4)-D-glucose]. The sera reacted only minimally in only the most sensitive assay (microscale enzyme-linked immunosorbent assay) with LTA from group A streptococci (this LTA contains a single kojibiosyl residue as part of the glycolipid moiety of the molecule and failed to react with the Lactobacillus fermentum LTA which is substituted with alpha-D-galactopyranosyl-(1----2)-D -glucosyl units.

The role of lipopolysaccharide structure in the recipient cell during plasmid-mediated bacterial conjugation

The role of the lipopolysaccharide (LPS) structure in the recipient cell during bacterial conjugation was studied using a series of well-defined LPS mutations in Salmonella minnesota. The plasmids Flac (IncFI) and R1drd19 (IncFII) transferred at a high frequency to the smooth S218 parent strain and the rough LPS mutants. However, R64drd1 1 (IncI alpha) transferred poorly to the LPS mutants compared with transfer to the smooth LPS parent strain. The decrease in R64drd1 1 transfer frequency correlated with the extent of the defect in LPS structure, suggesting that intact LPS on the recipient is a major requirement for R64drd1 1 mating. Transfer of the P-group plasmid, RK2, was not affected by changes in LPS structure. These results show that plasmids use different cell surface structures during conjugation, and that LPS is particularly important for R64drd1 1 transfer.

Multiple dose extraamniotic prostaglandin gel for second trimester termination of pregnancy

Multiple doses of PGF2 alpha gel were administered into the extraamniotic space in 30 patients to induce mid-trimester termination of pregnancy. In 18 of these patients, repeat doses of gel were given only in the absence of uterine contractions and in 12 patients the gel was administered every 4 hours, irrespective of uterine activity. The mean time to abortion in all patients was 13.9 hours; no benefit seemed to accrue from using routine 4-hourly doses and it is recommended that repeat doses are given only when contractions are absent. The latter technique compares favourably with the use of other natural prostaglandins and prostaglandin analogues.

Cell adhesion and chondrogenesis in brachypod mouse limb mesenchyme: fragment fusion studies

This study is a continuing investigation of the effect of the brachypod mouse mutation on cell interactions and chondrogenesis during early limb development. In this report, cell adhesiveness was assessed in fused fragments of brachypod and normal limb-bud mesenchyme. Examination of the interface of fused distal postaxial limb fragments show brachypod limb mesenchyme to be more adhesive than normal limb mesenchyme. Chondrogenesis within brachypod fragments is delayed and less extensive than in normal fragments. In addition, chondrogenesis within normal fragments is not affected by the juxtaposition of the brachypod fragment, and vice versa.

Reciprocal reactivities of specific thiols when actin binds to myosin

We report measurements of the reactivity (degree of labeling, as mole of ligand per mole of protein, at constant exposure time) of the reactive thiol, "SH1", of a subfragment of myosin (S-1), and of Cys-10 of F-actin under various conditions, using N-iodo-[3H]acetyl-N-(1-sulfo-5-naphthyl)ethylenediamine, a fluorescent radioactive iodoacetamide analog. When either ADP or adenyloyl imidodiphosphate (simulating unhydrolyzed ATP) is bound to the enzymatic site of S-1, the reactivity of "SH1" is slightly enhanced, but when active ATPase is going on, reactivity is reduced by about a third, presumably due to the species, (S-1) ADP,Pi. The reactivity of Cys-10 alone is very low. When the complex, (S-1)-F-actin, is formed, the reactivity of SH1 is strongly decreased, and the reactivity of Cys-10 is strongly increased. The foregoing results explain our further observation (on glycerol-treated rabbit psoas fibers) that when fibers labeled in relaxation solution are compared with fibers labeled in rigor solution, myosin is more reactive and actin is less reactive, in the former case; alpha-actinin and C-protein are also less reactive in the former case.