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1.
Reproduction ; 159(4): 397-408, 2020 04.
Article in English | MEDLINE | ID: mdl-31967968

ABSTRACT

Angiogenesis plays an integral role in follicular and luteal development and is positively regulated by several intra-ovarian factors including vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 2 (FGF2). Various transforming growth factor-ß (TGF-ß) superfamily members function as intra-ovarian regulators of follicle and luteal function, but their potential roles in modulating ovarian angiogenesis have received little attention. In this study, we used a bovine theca interna culture model (exhibiting characteristics of luteinization) to examine the effects of TGF-ß1 and bone morphogenetic protein 6 (BMP6) on angiogenesis and steroidogenesis. VEGFA/FGF2 treatment promoted endothelial cell network formation but had little or no effect on progesterone and androstenedione secretion or expression of key steroidogenesis-related genes. TGF-ß1 suppressed basal and VEGFA/FGF2-induced endothelial cell network formation and progesterone secretion, effects that were reversed by an activin receptor-like kinase 5 (ALK5) inhibitor (SB-431542). The ALK5 inhibitor alone raised androstenedione secretion and expression of several transcripts including CYP17A1. BMP6 also suppressed endothelial cell network formation under VEGFA/FGF2-stimulated conditions and inhibited progesterone secretion and expression of several steroidogenesis-related genes under basal and VEGFA/FGF2-stimulated conditions. These effects were reversed by an ALK1/2 inhibitor (K02288). Moreover, the ALK1/2 inhibitor alone augmented endothelial network formation, progesterone secretion, androstenedione secretion and expression of several steroidogenesis-related genes. The results indicate dual suppressive actions of both TGF-ß1 and BMP6 on follicular angiogenesis and steroidogenesis. Further experiments are needed to unravel the complex interactions between TGF-ß superfamily signalling and other regulatory factors controlling ovarian angiogenesis and steroidogenesis.


Subject(s)
Bone Morphogenetic Protein 6/physiology , Gonadal Steroid Hormones/biosynthesis , Neovascularization, Physiologic , Ovarian Follicle/physiology , Transforming Growth Factor beta1/physiology , Aminopyridines , Animals , Benzamides , Cattle , Cells, Cultured , Dioxoles , Female , Fibroblast Growth Factor 2 , Ovarian Follicle/blood supply , Phenols , Vascular Endothelial Growth Factor A
2.
Sci Rep ; 8(1): 10835, 2018 Jul 17.
Article in English | MEDLINE | ID: mdl-30018352

ABSTRACT

In this paper we describe the procedure for the optical calibration of large size deformable mirrors, acting as wavefront correctors for adaptive optics systems. Adaptive optics compensate the disturbance due to the atmospheric turbulence to restore the telescope resolution. We will showcase in particular the activities performed for the Adaptive Secondary Mirror (ASM) of the Magellan Adaptive Optics system (MagAO), which is an instrument for the 6.5 m Magellan Clay Telescope, located at Las Campanas Observatory, in Chile. The MagAO ASM calibration is part of the MagAO-2K project, a major MagAO upgrade that started in 2016 with the goal of boosting adaptive optics (AO) correction at visible wavelengths to image exoplanets. For the first time, the optical quality of MagAO mirror is reported. We describe the procedures developed to achieve high SNR interferometric measurements of the ASM modes under the presence of dome convection noise and telescope vibrations. These measurements were required to produce an improved control matrix with up to 500 modes to close the AO loop on sky with enhanced performances. An updated slaving algorithm was developed to improve the control of actuators vignetted by the central obscuration. The calibrations yielded also a new ASM flattening command, updating the one in use since the MagAO commissioning in 2013. With the new flattening command, a 22 nm RMS surface error was achieved. Finally, we present on-sky results showing the MagAO performance achieved with the new calibrations.

3.
J Eur Acad Dermatol Venereol ; 31(8): 1260-1270, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28252812

ABSTRACT

New all-oral direct-acting antivirals (DAA) have changed the hepatitis C virus (HCV) treatment landscape. Given that dermatologists frequently encounter HCV-infected patients, knowledge of the current treatment options and their utility in treating HCV-associated dermatologic disorders is important. In addition to highlighting the new treatment options, we review four classically HCV-associated dermatologic disorders - mixed cryoglobulinaemia (MC), lichen planus (LP), porphyria cutanea tarda (PCT) and necrolytic acral erythema (NAE) - and examine the role for all-oral direct-acting antiviral (DAA) regimens in their treatment. A literature search of English-language publications was conducted of the PubMed and EMBASE databases using search terms including 'hepatitis C', 'direct acting antivirals', 'cutaneous', 'mixed cryoglobulinemia', 'necrolytic acral erythema', 'lichen planus', 'porphyria cutanea tarda', 'rash', as well as specific drug names, related terms and abbreviations. Currently, limited data exist on the use of DAAs in HCV-infected patients with cutaneous side-effects, although treatment of the underlying HCV is now recommended for nearly all patients, with the new drugs offering much-improved dosage schedules and side-effect profiles. The most data exist for MC, in which several studies suggest that DAAs and achievement of sustained virologic response (SVR) improve cutaneous symptoms. Studies of both older and newer regimens are limited by their small size, retrospective nature, lack of appropriate controls and wide variability in study protocols. Given the strong association, screening for HCV should be considered in patients with MC, LP, PCT and NAE.


Subject(s)
Antiviral Agents/therapeutic use , Cryoglobulinemia/virology , Erythema/virology , Hepacivirus/pathogenicity , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/drug therapy , Lichen Planus/virology , Porphyria Cutanea Tarda/virology , Humans
4.
BAOJ Pharm Sci ; 12015 Jan 05.
Article in English | MEDLINE | ID: mdl-25688382

ABSTRACT

Cabozantinib, a potent pan-tyrosine kinase inhibitor, has been reported to provide enhanced antitumor efficacy by simultaneously inhibiting both MET and VEGF pathways, which are critical to tumor angiogenesis, survival and migration. It's very poor water solubility prevents its administration by the intravenous route, which may be important in patients unable to take the drug orally. In this study, we developed an efficient PEG-lipid-based polymeric micelle formulation with enhanced drug solubility and stability for cabozantinib delivery. DSPE-PEG2000 micelles encapsulating cabozantinib were prepared by a thin-film rehydration method followed by a lyophilization process to generate the dry dosage form. The average hydrodynamic diameter of freshly prepared micelles was 11 nm with a narrow size distribution, and the dry micelle cake could be fully reconstituted by rehydration. Approximately 75% of the drug was encapsulated into the lyophilized cake, and a sustained drug release profile was observed in simulated normal physiological release medium. Compared with the free cabozantinib solution, the drug-loaded micelles displayed significantly enhanced intracellular accumulation and cytotoxicity in human glioblastoma cancer cells and non-small lung cancer cells. These results suggest that the micellar formulation of cabozantinib may serve as a promising nanocarrier in anticancer treatments.

5.
Eur J Trauma Emerg Surg ; 40(3): 241-7, 2014 Jun.
Article in English | MEDLINE | ID: mdl-26816057

ABSTRACT

INTRODUCTION: Pertrochanteric fractures of the proximal femur should be treated surgically, unless the medical condition of the patient does not allow it. Currently, there are two ways to fix these fractures; either with a sliding hip screw or with an intramedullary nail. However, there is much debate over which implant is the best for pertrochanteric fracture fixation. The sliding hip screw has been used over time with good clinical results. While it was true that with first generation intramedullary nails the risk of complications was higher, there is evidence supporting the superiority of intramedullary nails in these fractures when compared with sliding hip screws. This evidence is based on the good clinical results and fewer complications, due to an improvement in the design of the implants and surgical technique used by surgeons. In stable fractures, despite the method chosen for fixation, obtaining a good reduction prior to placing the implant is the most important factor that can be controlled by the surgeon. In stable fractures the surgeon experience is a strong factor to account for when choosing the type of implant. Clearly there are fracture patterns (reverse oblique and subtrochanteric extension) that benefit from the use of intramedullary devices due to the high risk of failure if plates are used. CONCLUSION: It is very important that the surgeon identifies these fractures, so the type of fixation device which is chosen achieves the greatest stability possible. The aim of this paper is not to convince the surgeon about using intramedullary nails, but highlight the potential benefits intramedullary nailing has when compared with the use of extramedullary devices.

6.
Reproduction ; 138(6): 869-81, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19786399

ABSTRACT

Ovarian function is dependent on the establishment and continual remodelling of a complex vascular system. This enables the follicle and/or corpus luteum (CL) to receive the required supply of nutrients, oxygen and hormonal support as well as facilitating the release of steroids. Moreover, the inhibition of angiogenesis results in the attenuation of follicular growth, disruption of ovulation and drastic effects on the development and function of the CL. It appears that the production and action of vascular endothelial growth factor A (VEGFA) is necessary at all these stages of development. However, the expression of fibroblast growth factor 2 (FGF2) in the cow is more dynamic than that of VEGFA with a dramatic upregulation during the follicular-luteal transition. This upregulation is then likely to initiate intense angiogenesis in the presence of high VEGFA levels. Recently, we have developed a novel ovarian physiological angiogenesis culture system in which highly organised and intricate endothelial cell networks are formed. This system will enable us to elucidate the complex inter-play between FGF2 and VEGFA as well as other angiogenic factors in the regulation of luteal angiogenesis. Furthermore, recent evidence indicates that pericytes might play an active role in driving angiogenesis and highlights the importance of pericyte-endothelial interactions in this process. Finally, the targeted promotion of angiogenesis may lead to the development of novel strategies to alleviate luteal inadequacy and infertility.


Subject(s)
Blood Vessels/physiology , Neovascularization, Physiologic/physiology , Ovary/blood supply , Animals , Cattle , Female , Humans , Luteal Phase/metabolism , Luteal Phase/physiology , Models, Biological , Ovarian Follicle/blood supply , Ovarian Follicle/metabolism , Ovarian Follicle/physiology , Ovary/physiology
7.
Opt Express ; 16(14): 10200-7, 2008 Jul 07.
Article in English | MEDLINE | ID: mdl-18607427

ABSTRACT

Using an optical vortex coronagraph and simple adaptive optics techniques, we have made the first convincing demonstration of an optical vortex coronagraph that is coupled to a star gazing telescope. We suppressed by 97% the primary star of a resolvable binary system, Cor Caroli. The stars had an angular separation of 1.9lambda/D at our imaging camera. The secondary star suffered no suppression from the vortex lens.

8.
Nature ; 433(7023): 286-9, 2005 Jan 20.
Article in English | MEDLINE | ID: mdl-15662417

ABSTRACT

Mass is the most fundamental parameter of a star, yet it is also one of the most difficult to measure directly. In general, astronomers estimate stellar masses by determining the luminosity and using the 'mass-luminosity' relationship, but this relationship has never been accurately calibrated for young, low-mass stars and brown dwarfs. Masses for these low-mass objects are therefore constrained only by theoretical models. A new high-contrast adaptive optics camera enabled the discovery of a young (50 million years) companion only 0.156 arcseconds (2.3 au) from the more luminous (> 120 times brighter) star AB Doradus A. Here we report a dynamical determination of the mass of the newly resolved low-mass companion AB Dor C, whose mass is 0.090 +/- 0.005 solar masses. Given its measured 1-2-micrometre luminosity, we have found that the standard mass-luminosity relations overestimate the near-infrared luminosity of such objects by about a factor of approximately 2.5 at young ages. The young, cool objects hitherto thought to be substellar in mass are therefore about twice as massive, which means that the frequency of brown dwarfs and planetary mass objects in young stellar clusters has been overestimated.

9.
Bioinformatics ; 21(5): 617-23, 2005 Mar 01.
Article in English | MEDLINE | ID: mdl-15501914

ABSTRACT

MOTIVATION: PSORTb v.1.1 is the most precise bacterial localization prediction tool available. However, the program's predictive coverage and recall are low and the method is only applicable to Gram-negative bacteria. The goals of the present work are as follows: increase PSORTb's coverage while maintaining the existing precision level, expand it to include Gram-positive bacteria and then carry out a comparative analysis of localization. RESULTS: An expanded database of proteins of known localization and new modules using frequent subsequence-based support vector machines was introduced into PSORTb v.2.0. The program attains a precision of 96% for Gram-positive and Gram-negative bacteria and predictive coverage comparable to other tools for whole proteome analysis. We show that the proportion of proteins at each localization is remarkably consistent across species, even in species with varying proteome size. AVAILABILITY: Web-based version: http://www.psort.org/psortb. Standalone version: Available through the website under GNU General Public License. CONTACT: psort-mail@sfu.ca, brinkman@sfu.ca SUPPLEMENTARY INFORMATION: http://www.psort.org/psortb/supplementaryinfo.html.


Subject(s)
Bacterial Proteins/metabolism , Gene Expression Profiling/methods , Gram-Negative Bacteria/metabolism , Gram-Positive Bacteria/metabolism , Proteome/metabolism , Sequence Analysis, Protein/methods , Software , Subcellular Fractions/metabolism , Algorithms , Sequence Alignment/methods
11.
Mol Microbiol ; 37(5): 1186-97, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10972835

ABSTRACT

The Cpx envelope stress response of Escherichia coli is controlled by a two-component regulatory system that senses misfolded proteins in extracytoplasmic compartments and responds by inducing the expression of envelope protein folding and degrading factors. We have proposed that in the absence of envelope stress the pathway is maintained in a downregulated state, in part through interactions between the periplasmic inhibitor molecule CpxP and the sensing domain of the histidine kinase CpxA. In this study, we show that depletion of the periplasmic contents of the cell by spheroplast formation does indeed lead to induction of the Cpx envelope stress response. Further, removal of CpxP is an important component of this induction because tethering an MBP-CpxP fusion protein to the spheroplast inner membranes prevents full activation by this treatment. Spheroplast formation has previously been demonstrated to induce the expression of a periplasmic protein of unknown function, Spy. Analysis of spy expression in response to spheroplast formation by Western blot analysis and by lacZ operon fusion in various cpx mutant backgrounds demonstrated that spy is a member of the Cpx regulon. Interestingly, although the only known spy homologue is cpxP, Spy does not appear to perform the same function as CpxP as it is not involved in inhibiting the Cpx envelope stress response. Rather, deletion of spy leads to activation of the sigmaE stress response. Because the sigmaE response is specifically affected by alterations in outer membrane protein biogenesis, we think it possible that Spy may be involved in this process.


Subject(s)
Bacterial Proteins/metabolism , Escherichia coli Proteins , Escherichia coli/physiology , Membrane Proteins/metabolism , Periplasmic Proteins , Amino Acid Sequence , Bacterial Outer Membrane Proteins/metabolism , Bacterial Proteins/genetics , Carrier Proteins/genetics , Carrier Proteins/metabolism , Cell Membrane/metabolism , Collectins , Escherichia coli/growth & development , Gene Expression Regulation, Bacterial , Membrane Proteins/genetics , Molecular Sequence Data , Regulon , Sigma Factor/metabolism , Transcription Factors/metabolism
12.
Ann Pharmacother ; 34(6): 802-7, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10860142

ABSTRACT

OBJECTIVE: To evaluate the role of gabapentin for the treatment of neuropathic pain. DATA SOURCES: Clinical literature was identified through MEDLINE (from 1990 to October 1999). Key search terms were gabapentin and pain. DATA SYNTHESIS: Neuropathic pain can be a problematic, chronic syndrome that is frequently refractory to current drug treatments. Gabapentin is a newer generation antiepileptic drug that is commonly used in treatment of neuropathic pain. An evaluation of clinical trials using gabapentin to treat neuropathic pain was performed. CONCLUSIONS: Gabapentin appears to be effective in treating various neuropathic pain disorders. Gabapentin may have advantages over current therapies, such as a favorable safety profile and lack of drug interactions; however, cost issues and limited experience may limit the use of gabapentin as a first-line option.


Subject(s)
Acetates/therapeutic use , Amines , Analgesics/therapeutic use , Cyclohexanecarboxylic Acids , Neuralgia/drug therapy , gamma-Aminobutyric Acid , Acetates/economics , Analgesics/economics , Gabapentin , Humans , Neuralgia/etiology
13.
Nurs Manage ; 29(7): 41-5, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9807451

ABSTRACT

Advanced practice nurses and staff nurse skin-care team members provided the necessary expertise and information to integrate AHCPR recommendations in a protocol for patients at risk for skin impairment. Regular practice monitoring and education regarding skin management have proven to be successful strategies. A skin-impairment management protocol is provided.


Subject(s)
Nursing Assessment/methods , Patient Care Planning , Pressure Ulcer/etiology , Pressure Ulcer/prevention & control , Skin Care/methods , Adult , Decision Support Techniques , Humans , Nursing Records , Practice Guidelines as Topic , Predictive Value of Tests , Risk Factors
14.
Ophthalmology ; 105(10): 1907-14, 1998 Oct.
Article in English | MEDLINE | ID: mdl-9787363

ABSTRACT

OBJECTIVE: To report a pilot study of telemedical direct ophthalmoscopy in the diagnosis of acquired immune deficiency syndrome (AIDS)-related retinopathy in a human immunodeficiency virus (HIV)-positive population and in the diagnosis of glaucoma, cataract, and retinopathy in a diabetic population. DESIGN: Prospective comparative case series. PARTICIPANTS: Seventeen HIV-positive and 20 diabetic patients. METHODS: A direct ophthalmoscope custom-fitted with a digital microcamera capable of transmitting images from any of 61 sites within the Georgia Statewide Telemedicine Program was used by a nonophthalmologist to examine 34 eyes of 17 HIV-positive patients and 39 eyes of 20 patients with diabetes. Fundus images were transmitted in real-time to a reviewing ophthalmologist. An in-person, comprehensive examination including indirect ophthalmoscopy, was performed by a second ophthalmologist. Telemedical examination was compared to the in-person comprehensive examination. RESULTS: For the HIV study, 21 eyes did not show HIV retinopathy (noninfectious retinopathy with cotton-wool spots) by in-person examination. Telemedical examination correctly identified 20 of these eyes as disease-free (specificity = 95%). HIV retinopathy was present in 12 of the 34 eyes by in-person evaluation with telemedical examination correctly diagnosing 10 of these eyes (sensitivity = 83%). One eye with dense cataract and retinal detachment was unable to be evaluated ophthalmoscopically by either in-person or telemedical examination. Telemedical and in-person assessments for HIV retinopathy were identical in 100% of eyes without cataract. Disagreement in diagnosis between telemedical and in-person examination was associated with cataract (P < 0.0007). For the diabetes study, because of an inadequate image, telemedical examination was unable to classify 46% and 36% of eyes for glaucoma and diabetic retinopathy, respectively. Inability to make a telemedical determination for glaucoma (P < 0.011), nonproliferative (P < 0.064) and proliferative (P < 0.064) diabetic retinopathy was associated with cataract. Of the eyes that were able to be assessed by telemedical examination for diabetic retinopathy (n = 25), glaucoma (n = 21), and cataract (n = 39), the accuracy was poor (sensitivity = 29%, 50%, and 41%, respectively). Telemedical examination for diabetic retinopathy and glaucoma was more likely to agree with in-person examination in eyes without cataract as compared to eyes with cataract (not statistically significant). CONCLUSION: Telemedical direct ophthalmoscopic, real-time fundus imaging may provide a valuable means for providing ophthalmic consultation to the primary care physician in younger patients without lens or media opacity, but is inadequate for eyes with any degree of lens or media opacity.


Subject(s)
Eye Diseases/diagnosis , Ophthalmoscopy/methods , Remote Consultation/standards , Acquired Immunodeficiency Syndrome/diagnosis , Adult , Aged , Cataract/diagnosis , Diabetes Mellitus/diagnosis , Female , Glaucoma/diagnosis , Humans , Male , Middle Aged , Ophthalmoscopes , Pilot Projects , Reproducibility of Results , Retinal Diseases/diagnosis , Sensitivity and Specificity
15.
Mol Microbiol ; 27(5): 1003-8, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9535089

ABSTRACT

The assembly defect of a mutant outer membrane protein, OmpF315, can be corrected by suppressor mutations that lower lipopolysaccharide (LPS) levels and indirectly elevate phospholipid levels. One such assembly suppressor mutation, asmB1, is an allele of lpxC (envA) whose product catalyses the first rate-limiting step in the lipid A (LPS) biosynthesis pathway. Besides reducing LPS levels, asmB1 confers sensitivity to MacConkey medium. A mutation, sabA1, that reverses the MacConkey sensitivity phenotype of asmB1 maps within fabZ (whose product is needed for phospholipid synthesis from a precursor) is also required for lipid A synthesis. In addition to reversing MacConkey sensitivity, the sabA1 mutation reverses the OmpF315 assembly suppression phenotype of asmB1. These results show that OmpF315 assembly suppression by asmB1, which is achieved by lowering LPS levels, can be averted by a subsequent aberration in phospholipid synthesis at a point where the biosynthetic pathways for these two lipid molecules split. OmpF315 assembly suppression can also be achieved in an asmB+ background where FabZ expression is increased. The data obtained in this study provide genetic evidence that elevated phospholipid levels and/or phospholipid to LPS ratios are necessary for assembly suppression.


Subject(s)
Bacterial Outer Membrane Proteins/biosynthesis , Escherichia coli/metabolism , Lipid A/biosynthesis , Phospholipids/biosynthesis , Escherichia coli/genetics , Genes, Suppressor , Hydro-Lyases/metabolism , Phospholipids/genetics , Suppression, Genetic
16.
J Glaucoma ; 7(1): 16-21, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9493110

ABSTRACT

PURPOSE: The authors quantitatively evaluate the kinetics of fluid transfer from microsurgical sponges in a laboratory model to understand the kinetics of mitomycin C (MMC) delivery. METHODS: The amount of fluid transferred from soaked methylcellulose (Weck-cel, Weck Inc., Durham, NC, U.S.A.) sponges to small pieces of hydrated or dry filter paper used to simulate episcleral tissue and Tenon fascia was measured as a function of time, sponge size, hydration status of the filter paper, and technique of sponge application. RESULTS: The time course of fluid delivery from methylcellulose sponges to filter paper was nonlinear and characterized by a rapid delivery phase over the first 15 to 30 seconds, followed by a slow phase extending to at least 5 minutes. Sponge size and baseline hydration of the paper significantly influenced the rate and amount of fluid delivered, as did replacing the sponge every minute with a new sponge. CONCLUSION: The transfer of fluid from a microsurgical sponge displays nonlinear kinetics, with the majority of delivery occurring in the first 15 to 30 seconds. Sponge size, hydration of the recipient tissue, and technique of sponge application are significant variables influencing the amount of fluid, and therefore mitomycin C, delivered.


Subject(s)
Antibiotics, Antineoplastic/pharmacokinetics , Methylcellulose , Mitomycin/pharmacokinetics , Surgical Sponges , Drug Delivery Systems/instrumentation , Models, Biological
17.
Am J Perinatol ; 14(4): 201-4, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9259928

ABSTRACT

Our objective was to determine if low levels of corticosteroid binding globulin (CBG) might explain the low serum total cortisol levels found in some extremely low-birth-weight (ELBW) infants. In a prospective study, serum total cortisol and CBG were measured in single blood samples from 31 ELBW infants, with a gestational age less than 28 weeks, in the first 8 days of life. Severity of illness was assessed using the Score for Neonatal Acute Physiology Perinatal Extension (SNAP-PE). The mean serum total cortisol (mean +/- 1 SD) was 9.2 +/- 9.8 mcg/mL and the mean CBG level was 1.4 +/- 0.31 mg/dL. There was no significant correlation between serum total cortisol and CBG levels (r = -0.18), severity of illness as measured by the SNAP-PE (r = +0.12), or birth weight (r = -0.12). Five of 31 infants, having a mean SNAP-PE score of 41, had serum total cortisol levels < or = 3.0 mcg/dL. Estimated mean serum free cortisol concentrations in these five infants (0.76 mcg/dL) were comparable to estimated free cortisol levels diagnostic of adrenal insufficiency in sick adult patients. Our findings indicate that CBG levels are lower in ELBW infants than in term infants, but low CBG levels do not explain the low serum total cortisol levels found in some very sick infants. Low cortisol levels in small premature infants may be adequate to support growth if the infant is well, but may result in a syndrome of adrenal insufficiency in those with severe illnesses.


Subject(s)
Hydrocortisone/blood , Infant, Very Low Birth Weight/blood , Stress, Physiological/blood , Transcortin/metabolism , Adult , Humans , Infant, Newborn , Infant, Premature , Prospective Studies , Radioimmunoassay , Random Allocation , Severity of Illness Index
18.
Clin Orthop Relat Res ; (331): 102-6, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8895625

ABSTRACT

A synthetic femur and tibia were used to create a model resurfacing total knee arthroplasty. The femoral component was placed in 7 degrees valgus; the tibial component was placed in 2 degrees varus with a 5 degrees posterior slope. The overall anatomic alignment was 5 degrees valgus. A series of radiographs were taken on 14 inch x 17 inch plates, in full extension and 10 degrees flexion, with the limb rotated, in 5 degree increments, from 20 degrees external rotation to 25 degrees internal rotation. Seven orthopaedic surgeons independently measured the tibiofemoral angle and tibial alignment for each series of radiographs; interobserver variability was insignificant. Average radiographic anatomic alignment ranged from 2.29 degrees valgus in 20 degrees external rotation and 10 degrees flexion, to 6.73 degrees valgus in 25 degrees internal rotation and 10 degrees flexion. Limb rotation and knee flexion of 10 degrees, either alone or in combination, had a highly statistically significant effect on measured values of the anatomic alignment. Tibial alignment ranged from 5 degrees varus in 20 degrees external rotation to 3 degrees valgus in 25 degrees internal rotation, with the knee flexed 10 degrees. The variability associated with changes in rotation was statistically significant. Changes associated with rotation, when the knee was flexed 10 degrees, were not significantly different than those measured with the knee fully extended. Even in a well aligned total knee arthroplasty, limb positioning at the time of radiographic assessment will alter the apparent alignment indices, making objective evaluation difficult.


Subject(s)
Knee Joint/diagnostic imaging , Knee Prosthesis/methods , Range of Motion, Articular , Humans , Knee Joint/anatomy & histology , Knee Joint/physiology , Models, Anatomic , Radiography , Rotation
19.
J Bacteriol ; 178(17): 5138-43, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8752330

ABSTRACT

A novel genetic scheme allowed us to isolate extragenic suppressor mutations that restored mutant OmpF assembly. One group of these mutations, termed asmB for assembly suppressor mutation B, permitted mutant OmpF assembly in a non-allele-specific manner. Genetic mapping analyses placed the asmB mutations at the 2-min region of the Escherichia coli K-12 chromosome. Further analyses revealed that the asmB mutations map within the envA (lpxC) gene, which encodes an enzyme needed for the synthesis of the lipid A moiety of lipopolysaccharide (LPS). Nucleotide sequence analysis showed that the asmB mutations caused a change from F-50 to S (F50S substitution) (asmB2 and asmB3) or a G210S substitution (asmB1) in EnvA. Cells bearing the asmB alleles displayed increased sensitivity to various hydrophobic compounds and detergents, suggesting an alteration within the outer membrane. Direct examination (of the LPS showed that its amounts were reduced by the asmB mutations, with asmB1 exerting a greater effect than asmB2 or asmB3. Thus, it appears that the asmB mutations achieve mutant OmpF assembly suppression by reducing LPS levels, which in turn may alter membrane fluidity.


Subject(s)
Alleles , Amidohydrolases/genetics , Bacterial Outer Membrane Proteins/metabolism , Escherichia coli/genetics , Suppression, Genetic , Bacterial Outer Membrane Proteins/genetics , Chromosome Mapping , Escherichia coli/metabolism , Lipid A/metabolism , Mutation , Phenotype , Phospholipids/metabolism
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