Cryopreserved human hepatocytes: characterization of drug-metabolizing enzyme activities and applications in higher throughput screening assays for hepatotoxicity, metabolic stability, and drug-drug interaction potential

Cryopreserved human hepatocytes were extensively characterized in our laboratory. The post-thaw viability, measured via dye exclusion, ranged from 55 to 83%, for hepatocytes cryopreserved from 17 donors. Post-thaw viability and yield (viable cells per vial) were found to be stable up to the longest storage duration evaluated of 120 days. Drug-metabolizing enzyme activities of the cryopreserved hepatocytes (mean of ten donors) as percentages of the freshly isolated cells were: 97%, for cytochrome P450 isoform (CYP) 1A2, 78% for CYP2A6, 96% for CYP2C9. 86% for CYP2Cl9, 90% for CYP2D6, 164% for CYP3A4, 76% for UDP-glucuronidase, and 88% for umbelliferone sulfotransferase. Known species-differences in 7-ethoxycoumarin (7-EC) metabolism were reproduced by cryopreserved hepatocytes from human, rat, rabbit, dog, and monkey, illustrating the utility of cryopreserved hepatocytes from multiple animal species in the evaluation of species-differences in drug metabolism. Higher throughput screening (HTS) assays were developed using cryopreserved human hepatocytes for hepatotoxicity, metabolic stability, and inhibitory drug-drug interactions. Dose-dependent cytotoxicity, measured using MTT metabolism as an endpoint, was observed for the known hepatotoxic chemicals tamoxifen, clozapine, cadmium chloride, diclofenac, amiodarone, tranylcypromine, precocene II, but not for 2-thiouracil. Cell density- and time-dependent metabolism of 7-EC and dextromethorphan were observed in the HTS assay for metabolic stability. Known CYP isoform-specific inhibitors were evaluated in the HTS assay for inhibitory drug-drug interactions. Furafylline, sulfaphenazole, quinidine, and ketoconazole were found to be specific inhibitors of CYP1A2, CYP2C9, CYP2D6, and CYP3A4, respectively. Tranylcypromine and diethyldithiocarbamate were found to be less specific, with inhibitory effects towards several CYP isoforms, including CYP2A6, CYP2C9, CYP2C19, and CYP2E1. These results suggest that cryopreserved human hepatocytes represent a useful experimental tool for the evaluation of drug metabolism, toxicity, and inhibitory drug-drug interaction potential.

Assessing tumor angiogenesis using macromolecular MR imaging contrast media

MRI enhanced with a macromolecular contrast medium (MMCM) has previously been shown to estimate tumor microvascular characteristics that correlate closely with histologic microvascular density, an established surrogate of tumor angiogenesis. A similar MMCM-enhanced MRI technique has now been used to investigate the acute tumor microvascular effects of antibody-mediated inhibition of vascular endothelial growth factor (VEGF), a well-studied and potent angiogenesis stimulator. Athymic rats xenografted with a human breast carcinoma (MDA-MB-435) were imaged after administration of albumin-gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA30) using a heavily T1-weighted three dimensional-spoiled gradient-refocused acquisition in a steady-state pulse sequence before and 24 hours after treatment with anti-VEGF antibody (single dose of 1 mg). Changes in longitudinal relaxivity (delta R1) were analyzed using a bidirectional two-compartment kinetic model to estimate tumor fractional blood volume (fBV) and permeability surface area product (PS). Data showed a significant decrease (P < 0.05) of tumor PS with respect to macromolecular contrast medium at 24 hours after treatment with anti-VEGF antibody. No significant change was observed in fBV. Suppression of tumor microvascular permeability induced by anti-VEGF antibody can be detected and quantified by MMCM-enhanced MRI. MRI grading of tumor angiogenesis and monitoring of anti-angiogenesis interventions could find wide clinical application.

Useful predictors of bile duct stones in patients undergoing laparoscopic cholecystectomy. McGill Gallstone Treatment Group

OBJECTIVE

The authors determined the most useful predictors of common bile duct (CBD) stones as diagnosed by endoscopic retrograde cholangiopancreatography (ERCP) in patients who underwent laparoscopic cholecystectomy (LC).

METHODS

Prospective and retrospective collection of historical, biochemical and ultrasonographic data was used. Receiver operating characteristics curve analysis was used to determine optimal biochemical cut-off values. Multivariate analysis using logistic regression with generation of the best model identifying independent predictors of CBD stones also was employed. Prospective validation of the model was performed on an independent group of patients.

RESULTS

Endoscopic retrograde cholangiopancreatographies were performed before LC in 106 patients, and after LC in 33. Only four of ten clinical variables evaluated independently predicted the presence of CBD stones. The optimal model predicted a 94% probability of CBD stones in a patient older than 55 years of age who presented with an elevated bilirubin (over 30 mumol/L) and positive ultrasound findings (a dilated CBD, and a CBD stone seen on ultrasound). This model was validated prospectively in a subsequent series of 49 patients in which the probability of CBD stone was only 8% when all four predictors were absent.

CONCLUSIONS

The identified independent clinical predictors of a CBD stone helps select a population of symptomatic gallstone bearers who benefit most from cholangiographic assessment.

Magnetic resonance imaging detects suppression of tumor vascular permeability after administration of antibody to vascular endothelial growth factor

Macromolecular contrast medium-enhanced magnetic resonance imaging (MRI) and tumor-volume measurements were applied to monitor the effects of anti-vascular endothelial growth factor (anti-VEGF) antibody on microvascular characteristics and tumor growth of MDA-MB-435 human breast cancer cells implanted in nude rats. Administration of anti-VEGF antibody (three 1 mg doses at 3-day intervals) induced significant reductions in tumor growth rates (p < 0.05) and in MRI-assayed microvascular permeabilities (p < 0.05). Results of the study were consistent with previous observations that new microvessels formed in response to angiogenesis are hyperpermeable, and with the hypothesis that hyperpermeability is a mechanistic element in angiogenesis. Variations in tumor-vessel hyperpermeability can be measured by contrast-enhanced MRI, which may prove useful for assessing antiangiogenesis therapy.

Inhibition of the complement membrane attack complex by the galactose-specific adhesion of Entamoeba histolytica

The human complement system is an important early host defense against infection. Entamoeba histolytica activates the complement system but is resistant to killing by complement C5b-9 complexes deposited on the membrane surface. Our aim was to identify components of the amebic plasma membrane that mediate resistance to human complement C5b-9 by screening for neutralizing monoclonal antibodies. A monoclonal antibody was identified that abrogated amebic resistance to C5b-9, and the mAb was shown to recognize the parasite's galactose-specific adhesin. The purified adhesin bound to C8 and C9 and conferred C5b-9 resistance to sensitive ameba upon reconstitution; these activities of the adhesin were inhibited by the antiadhesin mAb. The E. histolytica adhesin shared sequence similarities and antigenic cross-reactivity with CD59, a membrane inhibitor of C5b-9 in human blood cells, suggesting both molecular mimicry and shared complement-inhibitory functions.

Requirement for the SLP-76 adaptor GADS in T cell development

GADS is an adaptor protein implicated in CD3 signaling because of its ability to link SLP-76 to LAT. A GADS-deficient mouse was generated by gene targeting, and the function of GADS in T cell development and activation was examined. GADS- CD4-CD8- thymocytes exhibited a severe block in proliferation but still differentiated into mature T cells. GADS- thymocytes failed to respond to CD3 cross-linking in vivo and were impaired in positive and negative selection. Immunoprecipitation experiments revealed that the association between SLP-76 and LAT was uncoupled in GADS- thymocytes. These observations indicate that GADS is a critical adaptor for CD3 signaling.

Beta1 integrins participate in the hypertrophic response of rat ventricular myocytes

Multiple signaling pathways have been implicated in the hypertrophic response of ventricular myocytes, yet the importance of cell-matrix interactions has not been extensively examined. Integrins are cell-surface molecules that link the extracellular matrix to the cellular cytoskeleton. They can function as cell signaling molecules and transducers of mechanical information in noncardiac cells. Given these properties and their abundance in cardiac cells, we evaluated the hypothesis that beta1 integrin function is involved in the alpha1-adrenergic mediated hypertrophic response of neonatal rat ventricular myocytes. The hypertrophic response of this model required interaction with extracellular matrix proteins. Specificity of these results was confirmed by demonstrating that ventricular myocytes plated onto an anti-beta1 integrin antibody supported the hypertrophic gene response. Adenovirus-mediated overexpression of beta1 integrin augmented the myocyte hypertrophic response when assessed by protein synthesis and atrial natriuretic factor production, a marker gene of hypertrophic induction. DNA synthesis was not altered by integrin overexpression. Transfection of cultured cardiac myocytes with either the ubiquitously expressed beta1A integrin or the cardiac/skeletal muscle-specific beta1 isoform (beta1D) activated reporter expression from both the atrial natriuretic factor and myosin light chain-2 ventricular promoters, genetic markers of ventricular cell hypertrophy. Finally, suppression of integrin signaling by overexpression of free beta1 integrin cytoplasmic domains inhibited the adrenergically mediated atrial natriuretic factor response. These findings show that integrin ligation and signaling are involved in the cardiac hypertrophic response pathway.

Efficacy of topical povidone-iodine during the first week after ophthalmic surgery

PURPOSE

In the first postoperative day, povidone-iodine ophthalmic solution prevents an increase in conjunctival bacterial colony-forming units and decreases the species compared with antibiotic. We sought to determine whether these beneficial effects of povidone-iodine could be sustained during the first postoperative week.

METHODS

In 42 eyes of 35 consecutive patients, one or two drops of either a broad-spectrum antibiotic (polymyxin B sulfate-neomycin sulfate-gramicidin) or povidone-iodine 1.25% to 2.5% were placed in the treated eye or eyes at the conclusion of surgery and three times daily during the first postoperative week. Bacterial cultures were taken from both eyes at the end of surgery before instillation of either of the eyedrops and again 1 week later. Twenty-eight untreated eyes served as a control group.

RESULTS

During the first postoperative week, the number of colony-forming units and species increased in both treatment groups. Relative to the control group, both medications effectively reduced the mean number of colony-forming units at 1 week (P < .02), but their effects on colony-forming units did not significantly differ from each other (80 +/- 290 for the povidone-iodine-treated eyes and 75 +/- 90 for the antibiotic-treated eyes). At 1 week, the species count increased 281% in the antibiotic group but only 106% in the povidone-iodine group. Compared to the control group, eyes that received povidone-iodine had a significantly lower species count (P = .0097).

CONCLUSION

Povidone-iodine ophthalmic solution is an alternative to postoperative topical antibiotics because of its effectiveness in controlling conjunctival bacterial colony-forming units and species, its relatively low cost, and its availability.

Paclitaxel: a radiation sensitizer of human cervical cancer cells

Paclitaxel is an exciting chemotherapeutic agent active in a variety of malignant tumors. This study was designed to explore the radiosensitizing potential of paclitaxel in human cervical cancer cell lines. The cell lines ME180, SiHa, and MS751 were evaluated. Experiments were performed in the proliferative phase of growth. Paclitaxel doses were treated at 0.01x, 0.02x, 0.03x, 0.04x, and 0.05x peak plasma concentration (PPC) in ME180 and 0.001x, 0.002x, 0.003x, 0.004x, and 0.005x PPC in SiHa and MS751. Radiation (RT) doses of cobalt-60 were 0, 2, 4, 6, 8, and 10 Gy. In the combination group RT was given 48 hr after paclitaxel treatment. To allow for median effect analyses, combination doses were kept at a fixed ratio: 0.01x/2 Gy, 0.02x/4 Gy, 0.03x/6 Gy, 0.04x/8 Gy, and 0.05x/10 Gy for ME180 and 0.001x/2 Gy, 0.002x/4 Gy, 0.003x/6 Gy, 0.004x/8 Gy, and 0.005x/10 Gy in MS-751 and SiHa. Adenosine triphosphate bioluminescence was performed on Day 7 after treatment and compared to untreated controls. Dose-response data were fit to the linear quadratic model and mean inactivation dose D was calculated. Data analysis with t test was performed. The median effect principle was used to evaluate the nature of the interaction between the two therapeutic modalities. Paclitaxel increased radiation cytotoxicity in all three cell lines. Mean inactivation D values for RT versus combination were 6.70 (+/- 0.15) and 4.33 (+/- 0.43) (P = 0.004) in ME180, 6.08 (+/- 0.70) and 4.54 (+/- 0.093) (P = 0.033) in MS751, and 7.03 (+/- 0.46) and 5.97 (+/- 0.51) (P = 0.034) in SiHa. The interaction of paclitaxel and RT was found to be supraadditive in ME180 and SiHa and subadditive in MS751. We conclude that paclitaxel has modest radiation-sensitizing effects in cervical cancer cell lines and that further clinical trials should be considered.

Structural and thermochemical characterization of lipoxygenase-catechol complexes

A complex between native, iron(II) soybean lipoxygenase 3 and 4-nitrocatechol, a known inhibitor of the enzyme, has been detected by isothermal titration calorimetry and characterized by X-ray crystallography. The compound moors in the central cavity of the protein close to the essential iron atom, but not in a bonding arrangement with it. The iron ligands experience a significant rearrangement upon formation of the complex relative to their positions in the native enzyme; a water molecule becomes bound to iron in the complex, and one histidine ligand moves away from the iron to become involved in a hydrogen bonding interaction with the catechol. These changes in position result in a trigonal pyramid coordination geometry for iron in the complex. Molecular modeling and force field calculations predict more than one stable complex between 4-nitrocatechol and the central cavity of lipoxygenase 3, but the interaction having the small molecule in the same orientation as the one found in the crystal structure was the most favorable. These observations reveal specific details of the interaction between lipoxygenase and a small molecule and raise the possibility that changes in the ligand environment of the iron atom could be a feature of the product activation reaction or the catalytic mechanism.

Interaction of alpha-dansylated peptide inhibitors with porcine pepsin: detection of complex formation by fluorescence energy transfer and chromatography and evidence for a two-step binding scheme

Peptide inhibitors, specifically labeled at the alpha-amino terminus by dansylation, have been prepared by utilizing solid-phase peptide synthesis. Changes in fluorescence have been observed upon mixing these peptides with porcine pepsin that can be attributed to the formation of at least two complexes. Energy transfer between tryptophan residues of the protein and the dansyl group of the inhibitors has been detected by the unique excitation spectra generated. The kinetics of formation of the second complex can be correlated with inhibition of the catalytic activity of pepsin. Evidence for complex formation has also been obtained from gel filtration experiments using the fluorescent peptides.

Inhibition of pepsin by analogues of pepsinogen-(1-12)-peptide with substitutions in the 4-7 sequence region

Derivatives of the 1-12 sequence of pig pepsinogen were prepared by solid-phase peptide synthesis. The three derivatives contain substitutions in the 4-7 region of the 1-12 sequence. Glycine was used to replace the hydrophobic residues -Val-Pro-Leu-Val- in pairs. After cleavage and purification, the synthetic peptides were compared with a synthetic peptide of the native sequence, prepared at the same time, with respect to their ability to inhibit the pepsin-catalysed clotting of milk. Inhibitory potency, determined from plots of percentage inhibition versus concentration of synthetic peptide, is inversely correlated with the substitution of glycine residues for the hydrophobic residues. Therefore the equilibrium inhibition of pepsin by these peptides is dominated by the hydrophobic nature of the 4-7 sequence region.

Disrupting the PIKE-A/Akt interaction inhibits glioblastoma cell survival, migration, invasion and colony formation

The cyclin-dependent kinase 4 (CDK4) amplicon is frequently amplified in numerous human cancers including gliomas. PIKE-A, a proto-oncogene that is one of the important components of the CDK4 amplicon, binds to and enhances the kinase activity of Akt, thereby promoting cancer progression. To define the roles of the PIKE-A/Akt interaction in glioblastoma multiform (GBM) progression, we used biochemical protein/protein interaction (PPI) assays and live cell fluorescence-based protein complementation assays to search for small peptide antagonist from these proteins that were able to block their interaction. Here, we show that disruption of the interaction between PIKE-A and Akt by the small peptides significantly reduces glioblastoma cell proliferation, colony formation, migration and invasion. Disruption of PIKE-A/Akt association potently suppressed GBM cell proliferation and sensitized the cells to two clinical drugs that are currently used to treat GBM. Interestingly, GBM cells containing the CDK4 amplicon were more responsive to the inhibition of the PIKE-A/Akt interaction than GBM cells lacking this amplicon. Taken together, our findings provide proof-of-principle that blocking a PPI that is essential for cancer progression provides a valuable strategy for therapeutic discovery.

Evidence of an interaction between Mos and Hsp70: a role of the Mos residue serine 3 in mediating Hsp70 association

c-Mos is a germ cell-specific MAP kinase kinase kinase (MAPKKK) that plays an essential role during meiotic divisions of oocytes. c-Mos is a key component of an activity, cytostatic factor, required for metaphase II arrest of unfertilized eggs in vertebrates. To understand the regulation of c-Mos, we are investigating c-Mos-interacting proteins. We provide evidence that mouse c-Mos binds to Hsp70, a molecular chaperone. Hsp70 was found to associate with Mos ectopically expressed in COS-1 cells. Mos-Hsp70 complexes could be immunoprecipitated with both Mos and Hsp70 antibodies. Despite a low-abundance of Mos, the Hsp70 antibody immunoprecipitated Mos as the major protein. Of importance, the Mos protein present in anti-Hsp70 immunoprecipitates functioned as an active MAPKKK indicating that it is not grossly misfolded. It is known that c-Mos protein kinase activity in cell extracts of transfected COS-1 or NIH3T3 cells is labile. We found that the inclusion of adenosine triphosphate (ATP) in cell extracts protected against the loss of Mos kinase activity. In the absence of ATP from cell extracts, protein kinase activity of Mos was lost within 6 h on ice even though the Mos protein was not degraded and remained bound to Hsp70. Based on our identification of c-Mos-Hsp70 interaction, one of the roles of ATP may be to assist the regulation of c-Mos via ATP involvement in the protein-folding function of Hsp70 and possibly other molecular chaperones. We also detected by coimmunoprecipitation a physical association between endogenous c-Mos and Hsp70 in Xenopus eggs. To provide further evidence for the functional significance of Hsp70 interaction to Mos function, we show that the residue serine 3 in Mos, which is important for the regulation of protein kinase activity of Mos is also important for Hsp70 association.

Tumor blood volume assays using contrast-enhanced magnetic resonance imaging: regional heterogeneity and postmortem artifacts

Tumor blood volume (BV), subject to both morphologic and physiologic influences, can be measured using contrast-enhanced magnetic resonance imaging (MRI). The aims of this study were to determine whether MRI enhanced with a macromolecular contrast medium (MMCM) could resolve differences in BV between different tumor types, between different regions within tumors, and within the same tumor in life and after death. Tumor BV estimates were based on the MRI signal intensity responses in the tumors and in reference venous blood following enhancement with a blood pool MMCM using two mammary adenocarcinoma models. Estimates of BV were made before and immediately following death. An in vitro measurement of tumor gadolinium concentration following death was correlated with MRI enhancement. Statistically significant differences (P < 0.05) were observed in MRI-estimated tumor BV between tumor subtypes, between in vivo and postmortem measurements, and between the tumor periphery and tumor centers. MRI assays enhanced with a macromolecular contrast agent can resolve blood volume differences between tumor types, between regions within the same tumor, and between vital and postmortem states.

Evidence for an important role of serine 16 and its phosphorylation in the stabilization of c-Mos

The c-Mos serine/threonine protein kinase is an essential component of cytostatic factor (CSF), which is required for metaphase II arrest of eggs in vertebrates. Previously, we showed that c-Mos residue Ser-16 is phosphorylated in the ts110 Mo-MuSV-encoded Gag-Mos fusion protein. Here we provide evidence that Mos is phosphorylated at Ser-16 in transfected COS-1 cells. To investigate the role of this phosphorylation, Ser-16 was substituted with alanine or glutamic acid in full-length v-Mos (an Env-Mos fusion protein that contains 31 additional amino acids at the amino terminus of c-Mos), its mouse c-Mos equivalent version (v-Mos residues 32-374, hereafter referred to as Mos), and mouse c-Mos. Constructs expressing mutant versions of Mos were transfected into COS-1 and NIH3T3 cells in a transient and stable manner, respectively. Synthesis and proteolysis of Mos were evaluated by pulse-chase analysis of 35S-methionine-labeled proteins. Our findings indicate that the S16A mutant of Mos was highly unstable. It accumulated to approximately 10% of the level of wild-type Mos or its S16E mutant. In addition, the S16A mutation but not the S16E mutation inhibited Mos interaction with a cellular protein, p35, suggesting that phosphorylation at Ser-16 may promote Mos interaction with p35. As expected from its destabilizing effect, the S16A mutation caused a dramatic decrease in the cellular transforming activity of Mos (determined by soft-agar colony-formation assay with the stably transfected NIH3T3 cells), which is known to correlate with its CSF function. Efficient ubiquitin-mediated proteolysis of c-Mos requires proline as the second residue from the amino-terminus. In contrast to Mos, neither the stability nor protein kinase activity of v-Mos (in which c-Mos residue Pro-2 becomes Pro-33) was affected by the S16A mutation. To provide further proof that, similar to c-Mos, the S16A mutant is recognized by the proteolysis system through Pro-2, we show that the effect of the S16A mutation is reversed by the Pro-2-Ala mutation. Thus, our results indicate that Ser-16 has an important role in the regulation of c-Mos and that phosphorylation at Ser-16 may inhibit proteolysis of c-Mos.

Evidence of a functional interaction between serine 3 and serine 25 Mos phosphorylation sites. A dominant inhibitory role of serine 25 phosphorylation on Mos protein kinase

Recently, we identified the major in vivo phosphorylation site on v-Mos as Ser-56, which is phosphorylated by cyclic AMP dependent protein kinase (PKA). Others have shown that c-Mos phosphorylation at Ser-3 (equivalent to Ser-34 in v-Mos) is important for the interaction of c-Mos with its substrate MEK and for its stability and cytostatic factor activity in eggs. To investigate the role of Ser-56 phosphorylation, we generated site-directed mutants of v-Mos that would mimic phosphorylation in terms of charge at positions 56 and 34. After mutating serine (S) residues with alanine (A) or glutamic acid (E) in different combinations, various v-Mos mutants were expressed in a rabbit reticulocyte lysate in vitro translation system and in COS-1 or NIH/3T3 cells. The effect of mutations on Mos function was evaluated by in vitro protein kinase assays and by the ability of Mos to cause neoplastic transformation of NIH/3T3 cells. The S56E but not the S56A mutation inhibited v-Mos kinase activity suggesting that Ser-56 phosphorylation has an inhibitory role. As predicted from Xenopus c-Mos studies, S34A but not S34E mutation inhibited v-Mos activity. Studies with the double mutants showed that the S56E mutation but not S56A mutation inhibited v-Mos kinase activity of both S34A and S34E mutants. Interestingly, the S56A mutation blocked the inhibitory effect of the S34A mutation on v-Mos kinase suggesting that in c-Mos the corresponding serine (Ser-25) can influence the regulation of c-Mos by Ser-3. Results showing inhibition of v-Mos kinase activity of the S34E mutant by the S56E mutation is significant as it suggests that doubly phosphorylated Mos at these residues would be inactive. Because residues corresponding to both v-Mos Ser-34 and Ser-56 are evolutionarily conserved in c-Mos, the kinase activity of c-Mos during meiosis may also be regulated in the same manner as v-Mos kinase activity.

Scintigraphic diagnosis of polysplenia in the adult

PURPOSE

The authors describe an adult patient with low index of suspicion for polysplenia. The diagnostic contribution of various investigative modalities is considered, and the key role of scintigraphy is specifically highlighted.

RESULTS

CT scan findings revealed multiple abdominal and retroperitoneal masses. Needle biopsy of a flank mass was nonspecific. Tc-99m sulfur colloid liver spleen scintigraphy and Tc-99m heat-denatured RBC scans showed the presence of polysplenia.

CONCLUSIONS

Multiple spleens can be mistaken for abdominal neoplasms on CT. Biopsy results may not always be helpful. In patients in whom there is such a diagnostic dilemma, Tc-99m heat-denatured RBC scans can successfully establish the definitive diagnosis of polysplenia.

Does point-of-care ultrasonography improve diagnostic accuracy in emergency department patients with undifferentiated hypotension? An international randomized controlled trial from the SHOC-ED investigators

PURPOSE

Point-of-care ultrasonography (POCUS) is an established tool in the management of hypotensive patients in the emergency department (ED). We compared the diagnostic accuracy of a POCUS protocol versus standard assessment without POCUS in patients with undifferentiated hypotension.

METHODS

This was an international, multicenter randomized controlled trial included three EDs in North America and three in South Africa from September 2012 to December 2016. Hypotensive patients were randomized to early POCUS protocol plus standard care (POCUS group) or standard care without POCUS (control group). Initial and secondary diagnoses were recorded at 0 and 60 min. The main outcome was measures of diagnostic accuracy of a POCUS protocol in differentiating between cardiogenic and non-cardiogenic shock. Secondary outcomes were diagnostic performance for shock sub-types, as well as changes in perceived category of shock and overall diagnosis.

RESULTS

Follow-up was completed for 270 of 273 patients. For cardiogenic shock, the POCUS-based diagnostic approach (POCUS) performed similarly to the non-POCUS approach (control) for specificity [95.5% (89.9-98.5) vs.93.8% (87.7-97.5)]; positive likelihood ratio (17.92 vs 14.80); negative likelihood ratio (0.21 vs 0.09) and diagnostic odds ratio (85.6 vs 166.57), with a similar overall diagnostic accuracy between the two approaches [93.7% (88-97.2) vs 93.6% (87.8-97.2)]. Diagnostic performance measures were similar across sub-categories of shock.

CONCLUSION

This is the first randomized controlled trial to compare diagnostic performance of a POCUS protocol to standard care without POCUS in undifferentiated hypotensive ED patients. POCUS performed well diagnostically in undifferentiated hypotensive patients, especially as a rule-in test; however, performance did not differ meaningfully from standard assessment.

Diagnosis, complications, and treatment of dentoskeletal malocclusion

The frequency of correctable malocclusion makes it imperative that the condition be diagnosed and referred for appropriate treatment. A complete dentofacial examination, which assesses facial symmetry and the dentition in the transverse, sagittal, and centric relations, is appropriate. Early diagnosis is imperative because malocclusion leads to long-term complications such as temporomandibular joint (TMJ) dysfunctions, perodontal disease, obstructive sleep apnea, psychological disorders, and articulation errors. A combination of orthodontic treatment and orthognathic surgery will correct the dentoskeletal malocclusion and prevent any long-term complications. The purpose of this case report is to describe a patient with severe dentoskeletal malocclusion who benefitted from appropriate orthodontic treatment and orthognathic surgery.