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Ashouri JF, Davis JL, Farkas A, Durack JC, Ramachandran R, Dall'Era M. A young woman with systemic lupus erythematosus and extensive mesenteric vasculitis involving small and medium vessels. Arthritis Care Res (Hoboken) 2012; 64:1928-33. [DOI: 10.1002/acr.21833] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 08/13/2012] [Indexed: 12/28/2022]
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Holley AT, Broussard LJ, Davis JL, Hickerson K, Ito TM, Liu CY, Lyles JTM, Makela M, Mammei RR, Mendenhall MP, Morris CL, Mortensen R, Pattie RW, Rios R, Saunders A, Young AR. A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:073505. [PMID: 22852693 DOI: 10.1063/1.4732822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The UCNA collaboration is making a precision measurement of the β asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be ̅ε=0.9985(4).
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Abstract
Visual loss in infectious posterior uveitis or panuveitis can occur if proper therapy is delayed because of diagnostic uncertainty. Some disorders, such as acute retinal necrosis and bacterial endophthalmitis, can be rapidly progressive, and therefore require prompt and accurate diagnosis to guide initial therapy. Other more slowly evolving infections, such as toxoplasmic chorioretinitis or fungal endophthalmitis, can be worsened by empiric use of corticosteroids without specific antimicrobial coverage. Key ocular diagnostic features are helpful but highly variable with overlap with both non-infectious uveitis and neoplastic masquerades, even for key signs such as hypopyon. Close examination of the fundus with attention to color, location, size, border, and opacity of lesions and associated arteriolitis or frosted branch angiitis is helpful in the diagnosis of chorioretinitis. Ultrasonography is an important tool in the evaluation of eyes with suspected endophthalmitis, especially those with intracapsular infection or focal infected deposits. Testing of intraocular fluid can be extremely useful but suffers from inaccessibility, poor sensitivity, and test selections dependent on a presumptive diagnosis, which may be wrong. The dilemma for clinician is to make the correct diagnosis of a rare, blinding, variegated disease quickly enough to intercede with specific therapy or to apply empiric therapy in a sufficiently skilled manner to avert disaster and confirm the diagnosis by response to treatment. When non-infectious uveitis is in the differential, empiric corticosteroids must sometimes be used, at great risk, if clinical examination, ancillary testing, and any available intraocular diagnostic tests have failed to confirm a diagnosis.
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Kisembo HN, Boon SD, Davis JL, Okello R, Worodria W, Cattamanchi A, Huang L, Kawooya MG. Chest radiographic findings of pulmonary tuberculosis in severely immunocompromised patients with the human immunodeficiency virus. Br J Radiol 2011; 85:e130-9. [PMID: 21976629 DOI: 10.1259/bjr/70704099] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVE We describe chest radiograph (CXR) findings in a population with a high prevalence of human immunodeficiency virus (HIV) and tuberculosis (TB) in order to identify radiological features associated with TB; to compare CXR features between HIV-seronegative and HIV-seropositive patients with TB; and to correlate CXR findings with CD4 T-cell count. METHODS Consecutive adult patients admitted to a national referral hospital with a cough of duration of 2 weeks or longer underwent diagnostic evaluation for TB and other pneumonias, including sputum examination and mycobacterial culture, bronchoscopy and CXR. Two radiologists blindly reviewed CXRs using a standardised interpretation form. RESULTS Smear or culture-positive TB was diagnosed in 214 of 403 (53%) patients. Median CD4+ T-cell count was 50 cells mm(-3) [interquartile range (IQR) 14-150]. TB patients were less likely than non-TB patients to have a normal CXR (12% vs 20%, p = 0.04), and more likely than non-TB patients to have a diffuse pattern of opacities (75% vs 60%, p = 0.003), reticulonodular opacities (45% vs 12%, p < 0.001), nodules (14% vs 6%, p = 0.008) or cavities (18% vs 7%, p = 0.001). HIV-seronegative TB patients more often had consolidation (70% vs 42%, p = 0.007) and cavities (48% vs 13%, p < 0.001) than HIV-seropositive TB patients. TB patients with a CD4+ T-cell count of ≤ 50 cells mm(-3) less often had consolidation (33% vs 54%, p = 0.006) and more often had hilar lymphadenopathy (30% vs 16%, p = 0.03) compared with patients with CD4 51-200 cells mm(-3). CONCLUSION Although different CXR patterns can be seen in TB and non-TB pneumonias there is considerable overlap in features, especially among HIV-seropositive and severely immunosuppressed patients. Providing clinical and immunological information to the radiologist might improve the accuracy of radiographic diagnosis of TB.
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Wearn JMG, Crisman MV, Davis JL, Geor RJ, Hodgson DR, Suagee JK, Ashraf-Khorassani M, McCutcheon LJ. Pharmacokinetics of pioglitazone after multiple oral dose administration in horses. J Vet Pharmacol Ther 2011; 34:252-8. [PMID: 21492190 DOI: 10.1111/j.1365-2885.2010.01217.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pioglitazone is a thiazolidinedione class of antidiabetic agent with proven efficacy in increasing insulin sensitivity in humans with noninsulin-dependent diabetes mellitus, a syndrome of insulin resistance sharing similarities with equine metabolic syndrome. The purpose of this study was to determine the pharmacokinetics of pioglitazone in adult horses following multiple oral dose administration. Pioglitazone hydrochloride (1 mg/kg) was administered orally for 11 doses at 24-h intervals, and plasma samples were collected. Initially, a pilot study was performed using one horse; and thereafter the drug was administered to six horses. Samples were analyzed by liquid chromatography with tandem mass spectrometry, and pharmacokinetic parameters were calculated using noncompartmental modeling. The maximum plasma concentration was 509.1 ± 413.5 ng/mL achieved at 1.88 ± 1.39 h following oral administration of the first dose, and 448.1 ± 303.5 ng/mL achieved at 2.83 ± 1.81 h (mean ± SD) following the eleventh dose. Apparent elimination half-life was 9.94 ± 4.57 and 9.63 ± 5.33 h after the first and eleventh dose, respectively. This study showed that in healthy horses, pioglitazone administered at a daily oral dose of 1 mg/kg results in plasma concentrations and total drug exposure approximating, but slightly below, those considered therapeutic in humans.
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Worodria W, Davis JL, Cattamanchi A, Andama A, den Boon S, Yoo SD, Hopewell PC, Huang L. Bronchoscopy is useful for diagnosing smear-negative tuberculosis in HIV-infected patients. Eur Respir J 2010; 36:446-8. [PMID: 20675782 DOI: 10.1183/09031936.00010210] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Clark HB, Greene BF, Macrae JW, McNees MP, Davis JL, Risley TR. A parent advice package for family shopping trips: development and evaluation. J Appl Behav Anal 2010; 10:605-24. [PMID: 16795570 PMCID: PMC1311239 DOI: 10.1901/jaba.1977.10-605] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
THIS ARTICLE REPORTS ON THE PRIMARY STEPS IN THE DEVELOPMENT OF PARENT ADVICE FOR POPULAR DISSEMINATION: (a) developing advice for one specific problem situation, family shopping trips; (b) testing the advice program for benefit to children and convenience to adults; and (c) packaging the advice so it can be used successfully by interested parents. Systematic observation of 12 families using the written advice package on shopping trips revealed its effectiveness in reducing child disruptions and increasing positive interactions between parents and children. These findings, along with interview information from families, showed that the package is usable, effective, and popular with both parents and children, and thus is ready for dissemination to a wide audience of parents-a step that in itself should involve research and evaluation.
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Smith GW, Davis JL, Smith SM, Gerard MP, Campbell NB, Foster DM. Efficacy and pharmacokinetics of pantoprazole in alpacas. J Vet Intern Med 2010; 24:949-55. [PMID: 20384953 DOI: 10.1111/j.1939-1676.2010.0508.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Despite frequent clinical use, information about the pharmacokinetics and efficacy of pantoprazole in camelids is not available. OBJECTIVES To examine the pharmacokinetics of both IV and SC pantoprazole and to determine whether pantoprazole administration would increase 3rd compartment pH in alpacas. ANIMALS Six healthy adult alpacas. METHODS Alpacas were fitted with a 3rd compartment cannula for measuring gastric pH. After recovery, alpacas received 1 mg/kg pantoprazole IV, q24h for 3 days or 2 mg/kg SC q24h for 3 days. Alpacas received both IV and SC pantoprazole, with a minimum of 3 weeks between treatments. Third compartment pH was recorded and plasma samples were taken for pharmacokinetic analysis. RESULTS Pantoprazole induced a slow but sustained increase in 3rd compartment pH when given by both the IV and SC routes. Third compartment pH was significantly increased as compared with baseline values (1.81+/-0.7; mean+/-SD) at 24 (2.47+/-0.8), 48 (3.53+/-1.0) and 72 hours (4.03+/-1.3) after daily IV administration of pantoprazole. Third compartment pH increased from 1.73+/-0.6 at baseline to 3.05+/-1.1, 4.02+/-1.4, and 3.61+/-1.6 at 24, 48, and 72 hours after SC administration, respectively. Pharmacokinetic analysis demonstrated that pantoprazole had a short elimination half-life (0.47+0.06 h) and a high clearance rate (12.2+/-2.9 mL/kg/min) after both IV and SC administration. CONCLUSIONS AND CLINICAL RELEVANCE Based on the results of this study, pantoprazole represents a safe and effective drug for increasing 3rd compartment pH in camelids. Either IV or SC administration is likely to be an effective treatment for gastric ulcers.
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Fei MW, Kim EJ, Sant CA, Jarlsberg LG, Davis JL, Swartzman A, Huang L. Predicting mortality from HIV-associated Pneumocystis pneumonia at illness presentation: an observational cohort study. Thorax 2009; 64:1070-6. [PMID: 19825785 DOI: 10.1136/thx.2009.117846] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Although the use of antiretroviral therapy has led to dramatic declines in AIDS-associated mortality, Pneumocystis pneumonia (PCP) remains a leading cause of death in HIV-infected patients. OBJECTIVES To measure mortality, identify predictors of mortality at time of illness presentation and derive a PCP mortality prediction rule that stratifies patients by risk for mortality. METHODS An observational cohort study with case note review of all HIV-infected persons with a laboratory diagnosis of PCP at San Francisco General Hospital from 1997 to 2006. RESULTS 451 patients were diagnosed with PCP on 524 occasions. In-hospital mortality was 10.3%. Multivariate analysis identified five significant predictors of mortality: age (adjusted odds ratio (AOR) per 10-year increase, 1.69; 95% CI 1.08 to 2.65; p = 0.02); recent injection drug use (AOR 2.86; 95% CI 1.28 to 6.42; p = 0.01); total bilirubin >0.6 mg/dl (AOR 2.59; 95% CI 1.19 to 5.62; p = 0.02); serum albumin <3 g/dl (AOR 3.63; 95% CI 1.72-7.66; p = 0.001); and alveolar-arterial oxygen gradient >or=50 mm Hg (AOR 3.02; 95% CI 1.41 to 6.47; p = 0.004). Using these five predictors, a six-point PCP mortality prediction rule was derived that stratifies patients according to increasing risk of mortality: score 0-1, 4%; score 2-3, 12%; score 4-5, 48%. CONCLUSIONS The PCP mortality prediction rule stratifies patients by mortality risk at the time of illness presentation and should be validated as a clinical tool.
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Cattamanchi A, Davis JL, Worodria W, den Boon S, Yoo S, Matovu J, Kiidha J, Nankya F, Kyeyune R, Byanyima P, Andama A, Joloba M, Osmond DH, Hopewell PC, Huang L. Sensitivity and specificity of fluorescence microscopy for diagnosing pulmonary tuberculosis in a high HIV prevalence setting. Int J Tuberc Lung Dis 2009; 13:1130-1136. [PMID: 19723403 PMCID: PMC2754584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
SETTING Mulago Hospital, Kampala, Uganda. OBJECTIVE To evaluate the diagnostic performance of fluorescence microscopy (FM) for diagnosing pulmonary tuberculosis (TB) in a high human immunodeficiency virus (HIV) prevalence setting. DESIGN Consecutive in-patients with cough for >2 weeks submitted two sputum specimens for smear microscopy. Smears were examined by conventional light microscopy (CM) and FM. The performance of the two methods was compared using mycobacterial culture as a reference standard. RESULTS A total of 426 patients (82% HIV-infected) were evaluated. FM identified 11% more smear-positive patients than CM (49% vs. 38%, P < 0.001). However, positive FM results were less likely than positive CM results to be confirmed by culture when smears were read as either 'scanty' (54% vs. 90%, P < 0.001) or 1+ (82% vs. 91%, P = 0.02). Compared to CM, the sensitivity of FM was higher (72% vs. 64%, P = 0.005), and the specificity lower (81% vs. 96%, P < 0.001). In receiver operating characteristic analysis, maximum area under the curve for FM was obtained at a threshold of >4 acid-fast bacilli/100 fields (sensitivity 68%, specificity 90%). CONCLUSION Although FM increases the sensitivity of sputum smear microscopy, additional data on FM specificity and on the clinical consequences associated with false-positive FM results are needed to guide implementation of this technology in high HIV prevalence settings.
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Banks HT, Davis JL, Ernstberger SL, Hu S, Artimovich E, Dhar AK, Browdy CL. A comparison of probabilistic and stochastic formulations in modelling growth uncertainty and variability. JOURNAL OF BIOLOGICAL DYNAMICS 2009; 3:130-148. [PMID: 22880825 DOI: 10.1080/17513750802304877] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We compare two approaches for inclusion of uncertainty/variability in modelling growth in size-structured population models. One entails imposing a probabilistic structure on growth rates in the population while the other involves formulating growth as a stochastic Markov diffusion process. We present a theoretical analysis that allows one to include comparable levels of uncertainty in the two distinct formulations in making comparisons of the two approaches.
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Douglas LC, Yi NY, Davis JL, Salmon JH, Gilger BC. Ocular toxicity and distribution of subconjunctival and intravitreal rapamycin in horses. J Vet Pharmacol Ther 2009; 31:511-6. [PMID: 19000272 DOI: 10.1111/j.1365-2885.2008.00986.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In vitro photosensitivity of rapamycin (RAPA) and ocular toxicity and distribution of intravitreal and subconjunctival RAPA was evaluated in normal horses. RAPA (2.5 mg, 5 mg, and 10 mg) was placed in 10 mL of PBS and maintained in a water bath at 37 degrees C, kept in the dark or subjected to room light, and sampled for up to 3 months for RAPA levels. Six normal adult horses received either 5 mg (n = 2) or 10 mg (n = 2) of RAPA intravitreally or 10 mg (n = 2) subconjunctivally. Ophthalmic exams and electroretinography (ERG) were performed prior to injection and on days 1, 7, 14, and 21 post-injection. Eyes were enucleated and samples were collected for RAPA concentrations and histopathology. No difference in light vs. dark RAPA concentrations was observed, suggesting a lack of RAPA phototoxicity. No evidence of ocular toxicity was noted on ophthalmic examination or histopathology. RAPA was not detected intraocularly 7 days post-injection in eyes receiving subconjunctival RAPA, but was detected in the vitreous at 21 days post-injection. Drug could be detected in both the aqueous and vitreous humor after intravitreal injection. Further study is needed to determine the efficacy of intravitreal RAPA.
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Webster DJ, Wilde ZJ, Orzol AR, Davis JL, Troxell ML, Bae D. Recombinant human G-CSF increases invasiveness of breast cancer cells. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-4057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abstract #4057
Background: Recombinant human granulocyte-colony stimulating factor (rhG-CSF) is commonly given to breast cancer patients to prevent neutropenia during chemotherapy. It binds to the G-CSF receptor (G-CSFR) on neutrophil precursors, promoting their proliferation within the bone marrow. We observed breast cancer growth in patients with advanced breast cancer during rhG-CSF administration. The G-CSFR is present on some solid tumors, but has not been examined in breast cancer. We asked whether breast cancer cells express the G-CSFR, and whether rhG-CSF has any direct effects on breast cancer proliferation or invasion in vitro.
 Material and Methods: MDA MB231 is a highly aggressive ER–PR–Her2/neu– breast cancer cell line derived from a human pleural effusion. We analyzed this cell line for the presence of the G-CSFR by immunohistochemistry, reverse-transcriptase PCR (RT-PCR), Western Blot analysis and flow cytometry. We sequenced DNA products of RT-PCR to verify results. We examined the effects of physiologic doses of rhG-CSF on breast cancer cell proliferation and invasion using MTT proliferation and Matrigel transwell assays, respectively.
 Results: MDA MB231 breast cancer cells express G-CSFR protein and mRNA. Of seven known G-CSFR isoforms, we found evidence of isoforms 1 and 4. Treating MDA MB231 breast cancer cells with rhG-CSF at 50ng/ml did not increase cell proliferation, but did increase invasion across a Matrigel-coated transwell membrane. Cells treated with rhG-CSF appeared more stellate than untreated cells. Studies are ongoing to evaluate which signal transduction pathways and genes are involved in this increased invasion response. The effects of rhG-CSF on breast cancer growth in vivo are also being examined in murine models.
 Discussion: rhG-CSF is given routinely as part of many adjuvant chemotherapy regimens for breast cancer. Although dose-dense regimens using rhG-CSF have shown equivalent or improved survival when compared to standard dosing regimens, it is possible that rhG-CSF may increase the growth or invasive potential of some breast cancers. It is also possible that rhG-CSF could mobilize breast cancer cells from the bone marrow, making these cells more susceptible to chemotherapy. These possibilities should promote thoughful use of rhG-CSF in the clinical setting, and should factor into the design and implementation of clinical trials using rhG-CSF.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4057.
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Cook VL, Jones Shults J, McDowell M, Campbell NB, Davis JL, Blikslager AT. Attenuation of ischaemic injury in the equine jejunum by administration of systemic lidocaine. Equine Vet J 2008; 40:353-7. [PMID: 18321812 DOI: 10.2746/042516408x293574] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
REASONS FOR PERFORMING STUDY Absorption of endotoxin across ischaemic-injured mucosa is a major cause of mortality after colic surgery. Recent studies have shown that flunixin meglumine retards mucosal repair. Systemic lidocaine has been used to treat post operative ileus, but it also has novel anti-inflammatory effects that could improve mucosal recovery after ischaemic injury. HYPOTHESIS Systemic lidocaine ameliorates the deleterious negative effects of flunixin meglumine on recovery of mucosal barrier function. METHODS Horses were treated i.v. immediately before anaesthesia with either 0.9% saline 1 ml/50 kg bwt, flunixin meglumine 1 mg/kg bwt every 12 h or lidocaine 1.3 mg/kg bwt loading dose followed by 0.05 mg/kg bwt/min constant rate infusion, or both flunixin meglumine and lidocaine, with 6 horses allocated randomly to each group. Two sections of jejunum were subjected to 2 h of ischaemia by temporary occlusion of the local blood supply, via a midline celiotomy. Horses were monitored with a behavioural pain score and were subjected to euthanasia 18 h after reversal of ischaemia. Ischaemic-injured and control jejunum was mounted in Ussing chambers for measurement of transepithelial electrical resistance (TER) and permeability to lipopolysaccharide (LPS). RESULTS In ischaemic-injured jejunum TER was significantly higher in horses treated with saline, lidocaine or lidocaine and flunixin meglumine combined, compared to horses treated with flunixin meglumine. In ischaemic-injured jejunum LPS permeability was significantly increased in horses treated with flunixin meglumine alone. Behavioural pain scores did not increase significantly after surgery in horses treated with flunixin meglumine. CONCLUSIONS Treatment with systemic lidocaine ameliorated the inhibitory effects of flunixin meglumine on recovery of the mucosal barrier from ischaemic injury, when the 2 treatments were combined. The mechanism of lidocaine in improving mucosal repair has not yet been elucidated.
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Davis JL, Morris A, Kallet RH, Powell K, Chi AS, Bensley M, Luce JM, Huang L. Low tidal volume ventilation is associated with reduced mortality in HIV-infected patients with acute lung injury. Thorax 2008; 63:988-93. [PMID: 18535118 DOI: 10.1136/thx.2008.095786] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Respiratory failure remains the leading indication for admission to the intensive care unit (ICU) and a leading cause of death for HIV-infected patients in spite of overall improvements in ICU mortality. It is unclear if these improvements are due to combination anti-retroviral therapy, low tidal volume ventilation for acute lung injury, or both. A study was undertaken to identify therapies and clinical factors associated with mortality in acute lung injury among HIV-infected patients with respiratory failure in the period 1996-2004. A secondary aim was to compare mortality before and after introduction of a low tidal volume ventilation protocol in 2000. METHODS A retrospective cohort study was performed of 148 consecutive HIV-infected adults admitted to the ICU at San Francisco General Hospital with acute lung injury requiring mechanical ventilation. Demographic and clinical information including data on mechanical ventilation was abstracted from medical records and analysed by multivariate analysis using logistic regression. RESULTS In-hospital mortality was similar before and after introduction of a low tidal volume ventilation protocol, although the study was not powered to exclude a clinically significant difference (risk difference -5.4%, 95% CI -21% to 11%, p = 0.51). Combination antiretroviral therapy was not clearly associated with mortality, except in patients with Pneumocystis pneumonia. Among all those with acute lung injury, lower tidal volume was associated with decreased mortality (adjusted odds ratio 0.76 per 1 ml/kg decrease, 95% CI 0.58 to 0.99, p = 0.043), after controlling for Pneumocystis pneumonia, serum albumin, illness severity, gas exchange impairment and plateau pressure. CONCLUSIONS Lower tidal volume ventilation is independently associated with reduced mortality in HIV-infected patients with acute lung injury and respiratory failure.
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Wong DM, Papich MG, Davis JL. Exposure to phenobarbital in a foal after nursing a mare treated with phenobarbital. J Vet Intern Med 2008; 22:227-30. [PMID: 18289315 DOI: 10.1111/j.1939-1676.2007.0036.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Davis JL, Welsh DA, Beard CB, Jones JL, Lawrence GG, Fox MR, Crothers K, Morris A, Charbonnet D, Swartzman A, Huang L. Pneumocystis colonisation is common among hospitalised HIV infected patients with non-Pneumocystis pneumonia. Thorax 2007; 63:329-34. [PMID: 18024536 DOI: 10.1136/thx.2007.088104] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND When Pneumocystis DNA is recovered from respiratory specimens of patients without Pneumocystis pneumonia (PCP), patients are said to be colonised with Pneumocystis, although the significance of this state is unknown. Understanding risk factors for and outcomes of colonisation may provide insights into the life cycle and transmission dynamics of Pneumocystis jirovecii. METHODS We performed a cross sectional study of the prevalence and clinical predictors of Pneumocystis colonisation in 172 HIV infected, PCP negative inpatients undergoing diagnostic evaluation of 183 episodes of pneumonia at either the Medical Center of Louisiana at New Orleans between 2003 and 2005 or San Francisco General Hospital between 2000 and 2005. DNA was extracted from sputum and bronchoalveolar lavage specimens and amplified using a nested PCR assay at the mitochondrial large subunit (18S) ribosomal RNA locus. Colonisation was deemed present if Pneumocystis DNA was identified by both gel electrophoresis and direct DNA sequencing. RESULTS 68% (117/172) of all patients were colonised with Pneumocystis. No strong associations with colonisation were identified for any demographic factors. Among clinical factors, having a CD4+ T cell count </=50 cells/mul (unadjusted OR 2.4, 95% CI 1.09 to 5.48; p = 0.031) and using PCP prophylaxis (unadjusted OR 0.55, 95% CI 0.29 to 1.07; p = 0.077) were associated with Pneumocystis colonisation, although the latter association may have been due to chance. After adjustment for CD4+ T cell count, use of PCP prophylaxis was associated with a decreased odds of colonisation (adjusted OR 0.45, 95% CI 0.21 to 0.98; p = 0.045). 11 patients who were colonised were subsequently readmitted for evaluation of a second episode of pneumonia; three were found to be colonised again, but none had PCP. CONCLUSIONS The majority of hospitalised HIV infected patients with non-PCP pneumonia are colonised with Pneumocystis. Failure to use co-trimoxazole prophylaxis and severe immunosuppression are associated with an increase in the odds of colonisation. Pneumocystis colonisation among hospitalised patients does not commonly lead to PCP.
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Tamisiea ME, Mitrovica JX, Davis JL. GRACE Gravity Data Constrain Ancient Ice Geometries and Continental Dynamics over Laurentia. Science 2007; 316:881-3. [PMID: 17495169 DOI: 10.1126/science.1137157] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The free-air gravity trend over Canada, derived from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, robustly isolates the gravity signal associated with glacial isostatic adjustment (GIA) from the longer-time scale mantle convection process. This trend proves that the ancient Laurentian ice complex was composed of two large domes to the west and east of Hudson Bay, in accord with one of two classes of earlier reconstructions. Moreover, GIA models that reconcile the peak rates contribute approximately 25 to approximately 45% to the observed static gravity field, which represents an important boundary condition on the buoyancy of the continental tectosphere.
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Davis JL, Papich MG, Morton AJ, Gayle J, Blikslager AT, Campbell NB. Pharmacokinetics of etodolac in the horse following oral and intravenous administration. J Vet Pharmacol Ther 2007; 30:43-8. [PMID: 17217400 DOI: 10.1111/j.1365-2885.2007.00811.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The purpose of this study was to determine the pharmacokinetics of etodolac following oral and intravenous administration to six horses. Additionally, in vitro cyclooxygenase (COX) selectivity assays were performed using equine whole blood. Using a randomized two-way crossover design, horses were administered etodolac (20 mg/kg) orally or intravenously, with a minimum 3-week washout period. Plasma samples were collected after administration for analysis using high pressure liquid chromatography with ultraviolet detection. Following intravenous administration, etodolac had a mean plasma half-life (t(1/2)) of 2.67 h, volume of distribution (Vd) of 0.29 L/kg and clearance (Cl) of 234.87 mL/h kg. Following oral administration, the average maximum plasma concentration (Cmax)) was 32.57 mug/mL with a t(1/2) of 3.02 h. Bioavailability was approximately 77.02%. Results of in vitro COX selectivity assays showed that etodolac was only slightly selective for COX-2 with a COX-1/COX-2 selectivity ratio effective concentration (EC)50 of 4.32 and for EC80 of 4.77. This study showed that etodolac is well absorbed in the horse after oral administration, and may offer a useful alternative for anti-inflammatory treatment of various conditions in the horse.
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Davis JL, Little D, Blikslager AT, Papich MG. Mucosal permeability of water-soluble drugs in the equine jejunum: a preliminary investigation. J Vet Pharmacol Ther 2006; 29:379-85. [PMID: 16958782 DOI: 10.1111/j.1365-2885.2006.00757.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ussing chambers have been used to study the mucosal permeability of drugs in humans, rats and other species. This data can then be used to develop in vitro/in vivo correlations (IVIVC) for drugs based on the Biopharmaceutics Classification System (BCS). Due to the poor oral bioavailability of many drugs in the horse, this method may be useful for screening drugs before development to determine if they warrant further study. Cephalexin (CPX), marbofloxacin (MAR), metronidazole (MTZ) and fluconazole (FCZ) were chosen for this study based on the wide range of physicochemical properties and bioavailability in the horse. Permeability was ranked as follows: MTZ > FCZ > MAR > CPX. This correlated with the bioavailability (R(2) = 0.633447), the Log P (R(2) = 0.648517), as well as the molecular weight (R(2) = 0.851208) of the drugs. Metronidazole induced a decrease in the tissue transepithelial resistance, suggestive of the possibility of tissue toxicity, which may have falsely increased its permeability. The low permeability of cephalexin across the tissue may indicate a lack of active transporters that are found in other species. From this study, we can conclude that the Ussing chamber is a promising method for determining mucosal permeability in the horse.
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Davis JL, Papich MG, Weingarten A. The pharmacokinetics of orbifloxacin in the horse following oral and intravenous administration. J Vet Pharmacol Ther 2006; 29:191-7. [PMID: 16669863 DOI: 10.1111/j.1365-2885.2006.00737.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The purpose of this study was to determine the pharmacokinetics and physicochemical characteristics of orbifloxacin in the horse. Six healthy adult horses were administered oral and intravenous orbifloxacin at a dose of 2.5 mg/kg. Plasma samples were collected and analyzed by high-pressure liquid chromatography with ultraviolet detection. Plasma protein binding and lipophilicity were determined in vitro. Following i.v. administration, orbifloxacin had a terminal half-life (t1/2) of 5.08 h and a volume of distribution (V(d(SS))) of 1.58 L/kg. Following oral administration, the average maximum plasma concentration (Cmax) was 1.25 microg/mL with a t1/2 of 3.42 h. Systemic bioavailability was 68.35%. Plasma protein binding was 20.64%. The octanol:water partition coefficient (pH 7.4) was 0.2 +/- 0.11. No adverse reactions were noted during this study. Dosage regimens were determined from the pharmacokinetic-pharmacodynamic parameters established for fluoroquinolone antibiotics. For susceptible bacteria, an oral dose of approximately 5 mg/kg once daily will produce plasma concentrations within the suggested range. This dose is suggested for further studies on the clinical efficacy of orbifloxacin for treatment of susceptible bacterial infections in the horse.
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Davis JL, Wernicke BP, Bisnath S, Niemi NA, Elósegui P. Subcontinental-scale crustal velocity changes along the Pacific–North America plate boundary. Nature 2006; 441:1131-4. [PMID: 16810252 DOI: 10.1038/nature04781] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 04/03/2006] [Indexed: 11/09/2022]
Abstract
Transient tectonic deformation has long been noted within approximately 100 km of plate boundary fault zones and within active volcanic regions, but it is unknown whether transient motions also occur at larger scales within plates. Relatively localized transients are known to occur as both seismic and episodic aseismic events, and are generally ascribed to motions of magma bodies, aseismic creep on faults, or elastic or viscoelastic effects associated with earthquakes. However, triggering phenomena and systematic patterns of seismic strain release at subcontinental (approximately 1,000 km) scale along diffuse plate boundaries have long suggested that energy transfer occurs at larger scale. Such transfer appears to occur by the interaction of stresses induced by surface wave propagation and magma or groundwater in the crust, or from large-scale stress diffusion within the oceanic mantle in the decades following clusters of great earthquakes. Here we report geodetic evidence for a coherent, subcontinental-scale change in tectonic velocity along a diffuse approximately 1,000-km-wide deformation zone. Our observations are derived from continuous GPS (Global Positioning System) data collected over the past decade across the Basin and Range province, which absorbs approximately 25 per cent of Pacific-North America relative plate motion. The observed changes in site velocity define a sharp boundary near the centre of the province oriented roughly parallel to the north-northwest relative plate motion vector. We show that sites to the west of this boundary slowed relative to sites east of it by approximately 1 mm yr(-1) starting in late 1999.
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de Schryver I, Rozenberg F, Cassoux N, Michelson S, Kestelyn P, Lehoang P, Davis JL, Bodaghi B. Diagnosis and treatment of cytomegalovirus iridocyclitis without retinal necrosis. Br J Ophthalmol 2006; 90:852-5. [PMID: 16597667 PMCID: PMC1857164 DOI: 10.1136/bjo.2005.086546] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To describe the diagnostic and therapeutic management of cytomegalovirus (CMV) anterior uveitis unassociated with retinal necrosis in immunocompetent patients. METHODS Patients referred between 2001 and 2003 for management of unilateral, chronic, recurrent uveitis associated with secondary glaucoma underwent extensive investigation including laboratory tests for herpes virus infections. Specific antiviral treatment was initiated in all cases and the level of ocular inflammation was evaluated during the follow up. RESULTS Five patients, three men and two women, were included. Median age was 50 years old (range 30-80 years). Anterior unilateral uveitis without iris atrophy was observed in all cases. Uveitis was chronic in three cases and recurrent in two cases. Glaucoma was observed in all patients with a median intraocular pressure of 30 mm Hg (range 22-43 mm Hg). Five patients responded initially to specific anti-CMV therapy. Even though glaucoma surgery was necessary in two cases, both ocular inflammation and glaucoma were controlled in all cases. Relapses occurred in three cases after cessation of therapy, requiring prolonged maintenance therapy with valganciclovir. CONCLUSIONS CMV infection and specific antiviral therapy should be considered in all cases of relapsing or chronic iridocyclitis and secondary glaucoma. Maintenance regimens of valganciclovir may be necessary to prevent further relapses.
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Abstract
Gastrogard, an oral formulation of omeprazole, was given to six llamas at a dose of 4 mg/kg once a day for 6 days. Plasma samples were collected at 0, 15, 30, 45, and 60 min and 2, 3, 4, 6, 8, 12, and 24 h on days 1 and 6. Plasma omeprazole concentrations were measured by high-pressure liquid chromatography with ultraviolet detection. Pharmacokinetic parameters calculated included the area under the curve (AUC(0-infinity)), peak plasma concentration (Cmax), time of peak plasma concentration (Tmax), and terminal half-life (t(1/2)). On day 6, plasma omeprazole concentrations reached a Cmax of 0.12 microg/mL at a Tmax of 45 min. The t(1/2) of omeprazole was 2.3 h and the AUC(0-infinity) was 0.38 h x microg/mL. Plasma concentrations remained above the minimum concentration for inhibition of gastric acid secretion projected from other studies on day 6 in all the llamas for approximately 6 h. However, the AUC(0-infinity) was below the concentrations associated with clinical efficacy. It was not possible to measure oral systemic bioavailability because there was no i.v. data collected from these animals. However, using data published on the i.v. pharmacokinetics of omeprazole in llamas, oral absorption was estimated to be only 2.95%. Due to low absorption the oral dose was increased to 8 and 12 mg/kg and studies were repeated. There were no significant differences in Cmax, Tmax, or AUC(0-infinity) for either of the increased doses. These results indicate that after 6 days of treatment with doses up to 12 mg/kg, oral omeprazole produced plasma drug concentrations which are not likely to be associated with clinical efficacy in camelids.
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Davis JL, Salmon JH, Papich MG. Pharmacokinetics and tissue fluid distribution of cephalexin in the horse after oral and i.v. administration. J Vet Pharmacol Ther 2005; 28:425-31. [PMID: 16207304 DOI: 10.1111/j.1365-2885.2005.00683.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to determine the pharmacokinetics and tissue fluid distribution of cephalexin in the adult horse following oral and i.v. administration. Cephalexin hydrate (10 mg/kg) was administered to horses i.v. and plasma samples were collected. Following a washout period, cephalexin (30 mg/kg) was administered intragastrically. Plasma, interstitial fluid (ISF) aqueous humor, and urine samples were collected. All samples were analyzed by high-pressure liquid chromatography (HPLC). Following i.v. administration, cephalexin had a plasma half-life (t(1/2)) of 2.02 h and volume of distribution [V(d(ss))] of 0.25 L/kg. Following oral administration, the average maximum plasma concentration (C(max)) was 3.47 mug/mL and an apparent half-life (t(1/2)) of 1.64 h. Bioavailability was approximately 5.0%. The AUC(ISF):AUC(plasma) ratio was 80.55% which corresponded to the percentage protein-unbound drug in the plasma (77.07%). The t(1/2) in the ISF was 2.49 h. Cephalexin was not detected in the aqueous humor. The octanol:water partition coefficient was 0.076 +/- 0.025. Cephalexin was concentrated in the urine with an average concentration of 47.59 microg/mL. No adverse events were noted during this study. This study showed that cephalexin at a dose of 30 mg/kg administered orally at 8 h dosage intervals in horses can produce plasma and interstitial fluid drug concentrations that are in a range recommended to treat susceptible gram-positive bacteria (MIC < or = 0.5 microg/mL). Because of the low oral bioavailability of cephalexin in the horse, the effect of chronic dosing on the normal intestinal bacterial flora requires further investigation.
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