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Abamectin is metabolized by CYP392A16, a cytochrome P450 associated with high levels of acaricide resistance in Tetranychus urticae. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 46:43-53. [PMID: 24463358 DOI: 10.1016/j.ibmb.2014.01.006] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/11/2014] [Accepted: 01/13/2014] [Indexed: 06/03/2023]
Abstract
Abamectin is one of the most important insecticides worldwide. It is used against major agricultural pests and insects of public health importance, as well as against endoparasites in animal health. Abamectin has been used successfully for the control of the spider mite Tetranychus urticae, a major agricultural pest with global distribution, an extremely diverse host range, and a remarkable ability to develop resistance against insecticides including abamectin. Target site resistance mutations may explain a large part of resistance, although genetic evidence and transcriptomic data indicated that additional mechanisms may also be implicated in the abamectin resistant phenotype. To investigate a functional link between cytochrome P450-mediated metabolism and abamectin resistance, we recombinantly expressed three cytochrome P450s (CYP392A16, CYP392D8 and CYP392D10) that have been associated with high levels of abamectin resistance in a resistant T. urticae strain isolated from Greece. CYP392A16 was expressed predominately in its P450 form however, both CYP392D8 and CYP392D10 were expressed predominately as P420, despite optimization efforts on expression conditions. CYP392A16 catalyses the hydroxylation of abamectin (Kcat=0.54 pmol/min/pmol P450; Km=45.9 μM), resulting in a substantially less toxic compound as confirmed by bioassays with the partially purified metabolite. However, CYP392A16 did not metabolize hexythiazox, clofentezine and bifenthrin, active ingredients that also showed reduced toxicity in the abamectin resistant strain. Among a number of fluorescent and luminescent substrates screened, Luciferin-ME EGE was preferentially metabolized by CYP392A16, and it may be a potential diagnostic probe for metabolic resistance detection and monitoring.
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Abstract
BACKGROUND Patients with multiple sclerosis (MS) are more frequently born in spring when compared to autumn. Fluctuation of UV-light has been hypothesized to drive this phenomenon. AIM To assess the correlation between fluctuation of sunlight and birth season in persons with MS. METHODS For this record-linkage study, we collected from the international MSBase and the Italian MS iMed-web databases the dates of birth of 11,415 patients with MS from 36 centres from 15 countries worldwide and compared these to dates of live-births from national registries. From all participating sites, we collected data on UV-light fluctuation and assessed its correlation with seasonal fluctuation in MS births. RESULTS Compared with the reference cohort, an increased proportion of persons with MS were born in spring and a decreased proportion in autumn (odds ratio (OR) to be born in spring versus autumn = 1.158, χ² = 36.347, P < 0.001). There was no significantly increased fluctuation of MS births with increased quartile of ambient UV-light fluctuation (Ptrend = 0.086). CONCLUSION Seasonal fluctuation of MS births as found in this worldwide cohort of patients with MS did not correlate with variation in seasonal fluctuation of UV-light. Most likely, it results from a complex interplay between fluctuation of sunlight, behavioural factors, other environmental factors and (epi)genetic factors.
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The evolving extension environment: implications for dairy scientists. ANIMAL PRODUCTION SCIENCE 2013. [DOI: 10.1071/an12347] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This paper reviews current challenges in the Australian extension environment and provides a case for developing an adaptive extension platform for the dairy sector in Australia and New Zealand, to support evolving dairy farm systems. The variation in the public-sector engagement in extension, the diversity and number of extension providers and a relatively uncoordinated approach to define new extension roles, functions and professional requirements are current challenges for dairy extension across Australia. In the dairy sector, these challenges coincide with increasing demand for a responsive research, development, extension and education system in supporting the rapid evolution in dairy farming systems. Addressing these challenges is not an issue for extension alone; however, the required level of integration among research, development, extension and education in an environment where needs are changing and resources are scarce demands an engaged dairy-science profession. Drawing on international extension and agricultural innovation-system literature and earlier empirical research, the following three areas for development are proposed: (1) a professional development strategy that incorporates (i) an understanding of the new professional situations extension works within, (ii) leadership in cross-industry and cross-sector coordination concerning the nature of the changing client in research, development, extension and education system and (iii) clear priorities for extension; (2) a professional development plan that incorporates a workplace-learning approach; and (3) for extension specialists to be engaged in defining research priorities, the agenda for change and suitable pathways for change alongside other professional groups, including farming. This development agenda will, however, require an adaptive extension platform to advance these areas on behalf of farmers and public stakeholders.
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EXPOSURE TO INTERFERON-β THERAPY IN EARLY PREGNANCY: A LITERATURE REVIEW OF PREGNANCY OUTCOMES IN WOMEN WITH MULTIPLE SCLEROSIS. Journal of Neurology, Neurosurgery and Psychiatry 2012. [DOI: 10.1136/jnnp-2012-304200a.64] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Impairment of the Vestibulo-Cerebellar Interaction in Friedreich's Ataxia (P02.252). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p02.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Relationship between chronic demyelination of the optic nerve and short term axonal loss. J Neurol Neurosurg Psychiatry 2012; 83:311-4. [PMID: 22193562 DOI: 10.1136/jnnp-2011-300928] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Axonal loss is a major determinant of disability in multiple sclerosis (MS). While acute inflammatory demyelination is a principal cause of axonal transection and subsequent axonal degeneration in acute disease, the nature of chronic axonal loss is less well understood. In the current study, the relationship between degree of chronic demyelination and axonal degeneration was investigated using optic neuritis (ON) as a model. METHOD 25 patients with a first episode of unilateral ON, good recovery of visual function and concurrent brain or spinal cord MRI lesions were enrolled. Axonal loss was assessed using change in retinal nerve fibre layer (RNFL) thickness between 1 and 3 years after ON. Optic nerve conduction was evaluated using latency of multifocal visual evoked potentials (mfVEP). The level of mfVEP latency delay at 12 and 36 months was considered indicative of the degree of permanent demyelination. Data from 25 age and gender matched normal controls were used for comparison. RESULTS RNFL thickness was significantly reduced in ON eyes at 12 months compared with controls but remained unchanged in fellow eyes. Average RNFL thickness demonstrated a small but significant reduction between 12 and 36 months for both ON and fellow eyes. Change in RNFL thickness between 12 and 36 months, however, did not correlate with the degree of mfVEP latency delay. CONCLUSION The results, therefore, show no association between the degree of permanent optic nerve demyelination (as measured by latency delay) and progressive axonal degeneration, at least in the early stages of the disease. The fact that fellow eyes demonstrated a similar degree of progressive axonal loss supports this suggestion.
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The effect of relative humidity on the effectiveness of the cyanoacrylate fuming process for fingermark development and on the microstructure of the developed marks. Forensic Sci Int 2011; 212:130-42. [DOI: 10.1016/j.forsciint.2011.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 06/02/2011] [Accepted: 06/03/2011] [Indexed: 10/18/2022]
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Abstract
BACKGROUND Recent studies demonstrate early diffuse central nervous system (CNS) inflammation in patients with multiple sclerosis (MS). The clinically unaffected (fellow) eye of patients with unilateral optic neuritis (ON) may reflect the status of normal-appearing white matter in the CNS, which can be assessed electrophysiologically. OBJECTIVE To study the relationship between electrophysiological parameters in the fellow eye of ON patients, and risk of conversion to MS. METHODS Forty-eight consecutive patients with acute unilateral ON were examined 12 months after ON of which 14 had MS, 19 remained high risk (HR) for MS, and 15 had low risk (LR) for MS according to McDonald's criteria. Twenty-five age-matched controls were also tested. Amplitude and latency of multifocal visual evoked potential (mfVEP) in the fellow eyes of patients at 12 months were analyzed and compared with controls. RESULTS Average mfVEP amplitude was 240 +/- 35, 232 +/- 36, 181 +/- 38, and 169 +/- 48 nV for controls, LR, HR, and MS groups respectively. Average mfVEP latency for controls, LR, HR, and MS patients was 139.7 +/- 5.5, 141.7 +/- 3.6, 145.9 +/- 8.9, and 152.0 +/- 9.9 ms respectively. CONCLUSIONS The magnitude of latency prolongation and amplitude decline 12 months after the initial episode was proportional to the risk of MS. The prognostic significance of these changes as predictors of subsequent MS should be investigated longitudinally.
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Multifocal VEP and OCT in optic neuritis: a topographical study of the structure-function relationship. Doc Ophthalmol 2008; 118:129-37. [PMID: 18779985 DOI: 10.1007/s10633-008-9147-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 08/19/2008] [Indexed: 11/30/2022]
Abstract
PURPOSE To investigate topographical relationship between amplitude of multifocal visual evoked potentials (mfVEP) and retinal nerve fibre layer (RNFL) thickness following acute optic neuritis (ON). PATIENTS AND METHODS Fifty patients with a clinical diagnosis of acute unilateral ON between 6 and 36 months prior to the study and 25 age-matched controls underwent mfVEP testing (Accumap V 2.1, ObjectiVision Pty Ltd, Sydney, Australia) and OCT imaging (fast RNFL protocol, Stratus, software version 3.0, Carl Zeiss Meditec, Inc., Dublin, CA). RNFL thickness and mfVEP amplitude were measured for upper, temporal and lower retinal sectors and corresponding areas of the visual field in affected eyes of ON patients and control eyes. Inter-eye asymmetry coefficients for both RNFL thickness and mfVEP amplitude were calculated for each zone, and corresponding coefficients were correlated between each other. RESULTS There was highly significant reduction of RNFL thickness and mean mfVEP amplitude in all three retinal sectors of the affected eye. Largest reduction of RNFL thickness was noticed in temporal sector and of mfVEP amplitude in corresponding central part of the visual field. RNFL thickness correlated highly with amplitude of the mfVEP derived from corresponding areas of the visual field in all three zones. CONCLUSIONS We demonstrated strong topographical associations between structural and functional measures of optic nerve integrity in patients with ON.
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Modified conservative management of polypropylene tape vaginal erosion. J OBSTET GYNAECOL 2008; 28:362-3. [PMID: 18569499 DOI: 10.1080/01443610802066083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Frontotemporal dementia and Parkinsonism linked to chromosome 17 in a young Australian patient with the G389R Tau mutation. Neuropathol Appl Neurobiol 2008; 34:366-70. [DOI: 10.1111/j.1365-2990.2007.00918.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Vestibular Rehabilitation in Individuals with Inner-Ear Dysfunction: A Pilot Study. Audiol Neurootol 2007; 13:19-28. [PMID: 17715466 DOI: 10.1159/000107434] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 05/04/2007] [Indexed: 11/19/2022] Open
Abstract
A randomised control prospective study was carried out examining patient outcomes after performing a 10-week vestibular home exercise programme. Thirty-two adults with vestibular dysfunction who reported vestibular symptoms negatively affecting daily life were enrolled. Test subjects were provided with an individualised vestibular rehabilitation programme designed by a physiotherapist. Control subjects received a set of strength and endurance exercises only. All subjects performed their exercises 3 times a day for 10 weeks. Subjective and objective patient measures were collected at 0, 6, 10 and 26 weeks. Results showed that both groups improved after beginning exercise, and that test subjects significantly benefited compared to the controls. These benefits were long term and measurable 6 months later. This study provides evidence that individualised vestibular exercises promote better outcomes for patients with vestibular dysfunction.
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417: Cyclosporine does not penetrate, but accumulates at high concentrations within, differentiated human airway epithelial cells in vitro: Possible implications for the use of inhaled cyclosporine. J Heart Lung Transplant 2007. [DOI: 10.1016/j.healun.2006.11.439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Abstract
OBJECTIVES The aims of this study were to investigate if (i) urinary concentrations of activin A and inhibin A are altered in pre-eclampsia (PE) and (ii) to study the relationship between uterine vein and peripheral vein concentrations of these hormones in PE patients. DESIGN AND METHOD In a retrospective study, maternal peripheral vein and uterine vein serum and maternal urine samples collected at the time of delivery were analysed. There were three groups of patients; (i) group 1: term normal pregnancies (n = 19) (ii) group 2: patients who developed PE < or = 37 weeks (n = 17) and (iii) group 3: patients who developed PE 37-40 weeks (n = 8). Serum and urinary activin A, follistatin, inhibin A and pro alpha C and urinary creatinine levels were measured using enzyme immunoassays in the laboratory. RESULTS Normal pregnant urine samples had very low levels of activin A and inhibin A. Both groups 2 and 3 PE patients had significantly higher levels of inhibin A (P < 0.001) and activin A (P < 0.001) compared to the controls. Pro-alpha C was not altered and follistatin was below the detection limit of the assay in the urine. Maternal peripheral serum activin A and inhibin A were significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. Pro-alpha C-containing inhibins were higher in group 2 patients (P < 0.05) compared to the controls in the peripheral circulation. Uterine vein serum activin A and inhibin A levels were also significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. There was a highly significant positive correlation between peripheral and uterine vein serum concentrations of activin A, follistatin, inhibin A and pro alpha C, suggesting the same source for these proteins in PE. CONCLUSION Urinary activin A and inhibin A are raised in groups 2 and 3 PE patients. The magnitude of rise (> 25-fold) suggests these proteins may rise in patients before the onset of the clinical symptoms of PE. Uterine vein levels of these proteins are also raised in PE.
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Visual disturbances representing occipital lobe epilepsy in patients with cerebral calcifications and coeliac disease: a case series. J Neurol Neurosurg Psychiatry 2004; 75:1623-5. [PMID: 15489401 PMCID: PMC1738780 DOI: 10.1136/jnnp.2003.031229] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Paroxysmal visual manifestations may represent epileptic seizures arising from the occipital lobe. In coeliac disease (CD) bilateral occipital calcifications and seizure semiology consistent with an occipital origin have been described, primarily in Mediterranean countries. By reporting three adult patients from an Australian outpatient clinic with visual disturbances, occipital cerebral calcifications, and CD, this study seeks to emphasise that CD should be considered even when patients of non-Mediterranean origin present with these symptoms. Seizure types included simple partial, complex-partial, and secondarily generalised seizures. The seizure semiology consisted of visual disturbances such as: blurred vision, loss of focus, seeing coloured dots, and brief stereotyped complex visual hallucinations like seeing unfamiliar faces or scenes. Symptoms of malabsorption were not always present. Neurological examination was unremarkable in two patients, impaired dexterity and mild hemiatrophy on the left was noted in one. Routine electroencephalography was unremarkable. In all cases, computed tomography demonstrated bilateral cortical calcification of the occipital-parietal regions. Magnetic resonance imaging showed no additional lesion. All patients had biopsy confirmed CD. Seizure control improved after treatment with gluten free diet and anticonvulsants. This report illustrates the association between seizures of occipital origin, cerebral calcifications, and CD even in patients not of Mediterranean origin.
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Abstract
Cytochrome P450 reductase (CPR) is a diflavin enzyme responsible for electron donation to mammalian cytochrome P450 enzymes in the endoplasmic reticulum. Dissection of the enzyme into functional domains and studies by site-directed mutagenesis have enabled detailed characterization of the mechanism of electron transfer using stopped-flow and equilibrium-perturbation methods, and redox potentiometry. These studies and the mechanism of electron transfer in CPR are reported herein.
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Abstract
A single case study is presented of an unusual dissociation between the sensory perception of an object and the grasping action towards the same object. The patient IW was found at age 74 to have spent all his life without the left parietal lobe, as a result of a congenital peri-natal insult. IW does not show any signs of sensory dysfunction, but he has a persistent motor bias that arises during movement towards objects. When IW was required to reach and grasp stationary and rotating objects, he consistently grasped the objects to the left side. Thus, it appears that information that is available at a sensory level can nevertheless be unavailable at a motor level. Our findings not only help to clarify the functions of the parietal lobe, but also show that lesions in this area are linked specifically to a process of response performance, which is fundamental for our understanding of visuomotor control.
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Abstract
OBJECTIVE To assess the effects of left parietal injury on covert visual attention during a detection task and a pointing task. METHODS The Posner's paradigm was given to a patient who was found at the age of 74 to have spent all his life without the left parietal lobe as a result of a congenital perinatal insult and to a control subject. In one session subjects were required to provide an arbitrary response at stimulus appearance (key press). In another session subjects were required to point to the stimulus. RESULTS The patient was able to disengage covert attention from a cued position when the task was to provide an arbitrary key press response in a similar fashion to a control subject with no neurological deficits. By contrast, he was impaired in disengaging attention from a cued position when the task was to reprogramme an overt pointing action. CONCLUSIONS Response to cued information is differentially available depending on task. It is suggested that mechanisms concerned with the attention for action systems are located within the left parietal lobe.
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Abstract
PURPOSE To highlight that internal carotid artery dissection is a common cause of Horner's syndrome and that it is important to diagnose dissection as anticoagulation can prevent carotid thrombosis and embolism. METHODS Five case reports are presented of patients with Horner's syndrome secondary to carotid dissection. One patient had carotid dissection secondary to trauma, two had spontaneous dissections and two had dissections in the settings of other illness. A literature search was performed on carotid dissection as a cause of Horner's syndrome and its diagnosis and management. RESULTS The case reports and literature highlight that dissection is under-recognized as a cause of Horner's syndrome and can be missed. The investigation of choice is a magnetic resonance imaging and angiography scan of the head and neck. The treatment advocated is anticoagulation for 3-6 months. CONCLUSION Carotid dissection should be suspected in patients with Horner's syndrome, particularly if head or neck pain is present.
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Active management of the third stage at caesarean section: a randomised controlled trial of misoprostol versus syntocinon. Aust N Z J Obstet Gynaecol 2001; 41:411-4. [PMID: 11787915 DOI: 10.1111/j.1479-828x.2001.tb01319.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The objective of this trial was to investigate whether 500 microg oral misoprostol given immediately after delivery of the neonate at Caesarean section is as effective as a bolus intravenous injection of 10 iu Syntocinon in stimulating uterine contractions and thereby reducing blood loss. Forty women undergoing elective or emergency Caesarean section were included in a placebo-controlled randomised trial. Group 1 received oral misoprostol and a placebo intravenous bolus and Group 2 received intravenous Syntocinon and oral placebo tablets. The main outcome measures were estimated blood loss at Caesarean section, drop in serum haemoglobin, and the need for additional uterotonic agents. We found that there was no significant difference (p = 0.75) in estimated blood loss between the two groups. No differences were observed in the decrease in haemoglobin, requirement for additional oxytocics, the need for blood transfusion or the degree of shivering in each group (p > 0.05 in each case). We concluded that oral misoprostol could be used as an alternative oxytocic agent for the third stage at Caesarean section. However, there is an obvious need for a larger randomised controlled trial to be undertaken. Previous published studies have concentrated on vaginal births and further studies should be extended to Caesarean deliveries.
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Abstract
AIM Ocular involvement in giant cell arteritis (GCA) is an ophthalmic emergency which, if untreated, can progress to permanent blindness. There is little evidence in the literature to support current protocols for the acute treatment of GCA with steroids. The authors sought to review the effects of intravenous and oral steroids in GCA. METHODS This retrospective study reviewed the records of 100 consecutive patients with biopsy proved giant cell arteritis. 73 patients with visual loss who were treated at the Royal Victorian Eye and Ear Hospital (RVEEH) and St Vincent's Hospital were included in the final series. The authors studied the management of the patients in the first week after presentation, analysing types of treatment, dose, effect on visual acuity, and complications. RESULTS All the patients except one had visual loss due to anterior ischaemic optic neuropathy (AION). 17 patients (23%) had bilateral eye involvement. Visual acuity improved in 21 of 73 patients (29%) by a mean of two Snellen chart lines after commencement of steroids. There was an increased likelihood of improved vision in the group who had intravenous steroids (40%) compared with those who received oral steroids (13%). In all except four patients (95%) vision remained stable at 1 month review. CONCLUSIONS Prompt treatment of GCA with steroids leads to improvement of visual acuity in a significant number of cases. Intravenous steroids may offer a greater prospect of improvement compared with oral steroids. A prospective trial comparing intravenous with oral steroids is needed to validate these findings and would not expose elderly patients to unacceptable risks.
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Trp-676 facilitates nicotinamide coenzyme exchange in the reductive half-reaction of human cytochrome P450 reductase: properties of the soluble W676H and W676A mutant reductases. Biochemistry 2000; 39:15990-9. [PMID: 11123926 DOI: 10.1021/bi002135n] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The kinetics of flavin reduction in two mutant forms of human cytochrome P450 reductase have been studied by stopped-flow spectroscopy with absorption and fluorescence detection. The mutant enzymes were altered at the position of Trp-676, which, by analogy with the structure of rat CPR, is close to the isoalloxazine ring of the enzyme-bound FAD. We show that mutant CPRs in which Trp-676 has been changed to histidine (W676H) and alanine (W676A) can be reduced by NADPH only to the two-electron level in single mixing stopped-flow experiments. The concentration dependence of the rate of hydride transfer indicates that the second, noncatalytic NADPH-binding site present in wild-type CPR is retained in the mutant enzymes. Detailed studies of W676H CPR indicate that further reduction of the enzyme beyond the two electron level is prevented due to the slow release of NADP(+) from the active site following the first hydride transfer from NADPH, owing to the stability of a reduced enzyme-NADP(+) charge-transfer complex. Reduction to the four-electron level is achieved in a sequential mixing stopped-flow experiment. In this procedure, W676H CPR is reacted first with a stoichiometric amount of NADPH, and then, following a delay of 100 ms, with excess NADPH. The data indicate that occupancy of the noncatalytic coenzyme site also hinders NADP(+) release from reduced enzyme. Fluorescence stopped-flow studies of the W676H and wild-type CPR enzymes reveal that the complex signals associated with reduction of wild-type CPR by NADPH are attributable to changes in the environment of residue W676. From these studies, a model is proposed for nicotinamide binding in wild-type CPR. In this model W676 serves as a trigger to release NADP(+) from the active site following hydride transfer. In the W676H enzyme, the slow release of NADP(+) is a consequence of the combined effects of (i) removing W676 by mutagenesis (thus removing the trigger for displacement) and (ii) the binding of NADPH in the noncatalytic site, thus trapping NADP(+) in the catalytic site.
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Abstract
BACKGROUND Susac syndrome is characterized by the triad of branch retinal arterial occlusions, encephalopathy and cochlear microangiopathy. The underlying process is believed to be a small vessel vasculitis causing microinfarcts in the retina, brain and cochlea. METHODS Analysis of two male and two female cases of Susac syndrome recognized in Australia. RESULTS In this series the epidemiology, mode of presentation, ophthalmologic features, neurologic and cochleo-vestibular features, radiologic characteristics, cerebrospinal fluid findings, therapeutic interventions, clinical course and outcome of Susac syndrome is examined. Key ophthalmologic differential diagnoses include systemic lupus erythematosis (SLE), Behçet's syndrome and other vasculitides such as sarcoidosis, tuberculosis, syphilis and lymphoma. Neuro-otologic features are most frequently misdiagnosed as multiple sclerosis. CONCLUSION Susac syndrome, first described in 1979, is becoming an increasingly recognized condition. Early recognition of the syndrome is important because treatment with systemic immunosuppression may minimize permanent cognitive, audiologic and visual sequelae.
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Making software upgrades a first-class experience. HEALTH MANAGEMENT TECHNOLOGY 2000; 21:22-3. [PMID: 11066922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Crystal structure of the FMN-binding domain of human cytochrome P450 reductase at 1.93 A resolution. Protein Sci 1999; 8:298-306. [PMID: 10048323 PMCID: PMC2144264 DOI: 10.1110/ps.8.2.298] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The crystal structure of the FMN-binding domain of human NADPH-cytochrome P450 reductase (P450R-FMN), a key component in the cytochrome P450 monooxygenase system, has been determined to 1.93 A resolution and shown to be very similar both to the global fold in solution (Barsukov I et al., 1997, J Biomol NMR 10:63-75) and to the corresponding domain in the 2.6 A crystal structure of intact rat P450R (Wang M et al., 1997, Proc Nat Acad Sci USA 94:8411-8416). The crystal structure of P450R-FMN reported here confirms the overall similarity of its alpha-beta-alpha architecture to that of the bacterial flavodoxins, but reveals differences in the position, number, and length of the helices relative to the central beta-sheet. The marked similarity between P450R-FMN and flavodoxins in the interactions between the FMN and the protein, indicate a striking evolutionary conservation of the FMN binding site. The P450R-FMN molecule has an unusual surface charge distribution, leading to a very strong dipole, which may be involved in docking cytochrome P450 into place for electron transfer near the FMN. Several acidic residues near the FMN are identified by mutagenesis experiments to be important for electron transfer to P4502D6 and to cytochrome c, a clear indication of the part of the molecular surface that is likely to be involved in substrate binding. Somewhat different parts are found to be involved in binding cytochrome P450 and cytochrome c.
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Abstract
Three patients with episodic ocular torsion and skew deviation due to mesodiencephalic lesions were studied by using binocular three-dimensional scleral search coils. The conjugate ocular torsion (upper pole of each eye rotating toward the side of the brainstem lesion) was initiated by a torsional fast eye movement. During prolonged episodes, torsional nystagmus was also present. Cessation of the ocular torsion and skew deviation occurred by slow eye movements with exponentially decreasing velocities in 2 patients, and by multiple fast torsional movements in 1 patient. In 1 patient, the abnormal eye movements were temporally linked to dystonic movements in the limbs on the side opposite the brainstem lesion. The occurrence of skew deviation with conjugate ocular torsion in brainstem lesions has been attributed to functional asymmetry in vestibular pathways responsible for the slow-phase compensatory eye movement response to roll. In comparison, the findings in our patients show that in mesodiencephalic lesions conjugate ocular torsion with skew deviation may be generated by torsional fast eye movements, indicating activation of the burst cells of the rostral interstitial nucleus of the medial longitudinal fasciculus.
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Processing of pro-tumour necrosis factor-α by venom metalloproteinases: a hypothesis towards explaining local tissue damage following snakebite. Toxicon 1997. [DOI: 10.1016/s0041-0101(97)90330-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Problem-based learning at the University of Southern California School of Dentistry. J Dent Educ 1997; 61:417-25. [PMID: 9193445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Responding to the recent Institute of Medicine report on dental education, the Center for Craniofacial Molecular Biology (CCMB) of the University of Southern California School of Dentistry has developed a parallel track program in dental education leading to the D.D.S. degree. This program was proposed in May of 1995, and the first class of twelve students was admitted in September of that year. Currently two classes are enrolled and plans to admit a further twelve students (Class of 2001) are in place. The educational strategy for this program is totally problem-based. Students work in groups of six with a faculty facilitator, not necessarily a content expert. Facilitators are largely drawn from the multidisciplinary pool of research faculty at the center. All learning is mediated through biomedical and biodental problem cases. No formal lectures or classes are scheduled. The learning of clinical dental skills is promoted through focussed dental patient simulations in which students review clinical charts, radiographs, medical reports and then explore identified, hands-on learning needs using patient simulators in a clinical context. Early patient exposure is obtained through dental office visits and other special patient clinics. Initial experience with this program suggests that the problem-based learning (PBL) students learn as well (if not better) than their traditional program peers and develop excellent group and cognitive analytical skills. The absence of a pool of dentally related biomedical cases suitable for a PBL program has necessitated the use of innovative approaches to their development and presentation. It is believed that this educational approach will produce dental clinicians equipped with the self-motivated, life-long learning skills required in the ever-changing world of bio-dental sciences in the twenty-first century.
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Non-coexpression of collagenase and transin in malignant epithelial cells. Int J Oncol 1997; 10:615-8. [PMID: 21533421 DOI: 10.3892/ijo.10.3.615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Increased synthesis and secretion of the matrix metalloproteinase has been associated with the acquisition of the invasive properties of malignant cells. In a rat malignant anaplastic cell line (T952/F7) sporadic expression of mRNA for collagenase-3 against a background of high transin-l mRNA has been shown. Sporadic induction of either metalloproteinase was not found in the benign precursor cells (A5P/B10) of T952/F7 cells, but a coordinate mRNA induction profile for these two genes could be induced by the addition of 12-O-tetradecanoylphorbol-13-acetate. In a different uncloned neoplastic epithelial cell line (BCl) fluctuations in the levels of collagenase and transin appeared coordinately, but coordinate expression was not a feature in cloned lines derived from BCl. The loss of coordinate regulation of the two matrix metalloproteinases may relate to the variability in metastatic potential seen in clonal cell lines.
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Crystallization and preliminary X-ray diffraction studies of human cytochrome P450 reductase. J Struct Biol 1996; 116:320-5. [PMID: 8812989 DOI: 10.1006/jsbi.1996.0048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The two functional domains of a cloned human fibroblast NADPH-cytochrome P450 reductase have been expressed in Escherichia coli and purified on the milligram scale for crystallization studies. One domain contains the cofactor FMN-binding site and the other contains the binding sites for cofactor FAD and substrate NADPH. Crystals of both domains have been obtained by the microbatch method. The crystals of the FMN domain belong to the monoclinic space group P21, with unit cell dimensions of a = 39.3 A, b = 51.5 A, c = 47.8 A, and beta = 105.7 degrees and have one molecule in the asymmetric unit. Diffraction data up to 2.3 A were collected with a merging residual on intensity of 9.3%. The crystals of the FAD/NADPH domain belong to the ortho-rhombic space group P212121 with unit cell dimensions of a = 55.9 A, b = 58.6 A, c = 131.1 A and have one molecule in the asymmetric unit. Diffraction data up to 2.6 A were collected with a merging residual on intensity of 8.0%.
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Abstract
Health care reform will affect the relationship of trauma centers to health maintenance organizations and other managed care plans. We studied Kaiser Permanente Medical Center (Kaiser) members admitted to the Trauma Center at San Francisco General Hospital (SFGH) to determine: (1) variables predicting transfer from SFGH to a Kaiser Hospital (repatriation), (2) the length of hospital stay (LOS), and (3) the cost of their care. The SFGH trauma registry provided data on 7,794 patients admitted before 1994. To investigate LOS, 89 Kaiser patients over 1 year were matched with non-Kaiser patients on age, maximum Abbreviated Injury Scale score (MAIS) by body region, Injury Severity Score (ISS), head injury severity, and blunt or penetrating injury and disposition. Kaiser patients were significantly younger, more likely to have blunt injury, and had a lower death rate. Significant predictors of repatriation were an MAIS score > or = 3, abdominal or extremity injury, and an ISS score of 26 to 40. The mean LOS for all Kaiser patients was 7.6 days, compared with 4.8 for controls (p = 0.20). However, mean LOS was significantly longer in repatriated Kaiser patients compared with controls (16 vs. 7.8 days, p < 0.0005). Kaiser reimbursement rates were comparable with commercial payors, but higher than others. A relatively small number of severely injured patients account for a large percentage of costly trauma care. Analyses of patient subsets are necessary for trauma centers to negotiate suitable relationships with managed care plans. A prospective study is needed to examine the cost efficiency of early transfer of managed care patients.
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Severe forms of infection with Angiostrongylus cantonensis acquired in Australia and Fiji. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1994; 24:415-6. [PMID: 7980247 DOI: 10.1111/j.1445-5994.1994.tb01480.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
OBJECTIVE In the absence of clear distinctions in alertness between patients with primary insomnia and normal subjects, the goal of this study was to identify psychometric and electrophysiological measures that would distinguish these two groups. METHOD The daytime alertness of 20 primary insomnia patients and 20 normal subjects was investigated through their scores on a 26-item hyperarousal scale and measurement of auditory evoked potentials and alpha and nonalpha band EEG activity. Statistical analysis of the data included correlation of the hyperarousal scores and the electrophysiological measures. RESULTS The hyperarousal scores showed clearly higher daytime alertness in the insomnia patients compared with the normal subjects. In addition, during wakefulness, the insomnia patients showed greater amplitudes of P1N1, a durable, intrinsic, late (cortical) component of the auditory evoked potential, as well as greater EEG activity across the frequency spectrum. The hyperarousal scores correlated positively with the amplitude of P1N1 at each of three sound intensities. CONCLUSIONS To the authors' knowledge, this is the first study to offer evidence that patients with primary insomnia have objectively definable features during wakefulness that clearly distinguish them from normal subjects. The measurement of hyperarousal might be used to refine descriptions of insomnia populations in experimental studies.
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Vetsure and the profession. Vet Rec 1989; 124:639. [PMID: 2773208 DOI: 10.1136/vr.124.24.639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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