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Smith AL, Wein AJ. Estrogen replacement therapy for the treatment of postmenopausal genitourinary tract dysfunction. DISCOVERY MEDICINE 2010; 10:500-510. [PMID: 21189221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Considerable debate exists over the use of estrogen replacement therapy in post-menopausal women. Valuable level 1 evidence has been obtained through randomized controlled clinical trials; even so, little consensus exists on its use. Several genitourinary complaints correlate temporally with estrogen depletion at the time of menopause; likewise, estrogen replacement has been felt to improve many of these conditions. We will review the indications and evidence for estrogen therapy in the treatment of genitourinary symptoms as well as the hallmark clinical trials that address urinary incontinence, overactive bladder symptoms, urinary tract infections, vaginal atrophy and dyspareunia.
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Smith AL, Wein AJ. Recent advances in the development of antimuscarinic agents for overactive bladder. Trends Pharmacol Sci 2010; 31:470-5. [DOI: 10.1016/j.tips.2010.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 07/14/2010] [Accepted: 07/16/2010] [Indexed: 10/19/2022]
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Smith AL, Wang PC, Anger JT, Mangione CM, Trejo L, Rodríguez LV, Sarkisian CA. Correlates of urinary incontinence in community-dwelling older Latinos. J Am Geriatr Soc 2010; 58:1170-6. [PMID: 20406311 DOI: 10.1111/j.1532-5415.2010.02814.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prevalence of urinary incontinence (UI) has varied in the literature and is reflective of the definition and sampling methodologies used, as well as the age, ethnicity, and sex being studied. The aim of the current study was to measure the prevalence and correlates of UI in a sample of 572 older Latinos participating in Caminemos, a trial of a behavioral intervention to increase walking. Participants completed an in-person survey and physical performance measures. UI was measured using the International Consultation on Incontinence item: "How often do you leak urine?" Potential correlates of UI included sociodemographic variables, body mass index, smoking, physical activity, medical comorbidity, physical performance, activity of daily living (ADL) impairment, use of assistive ambulatory devices, health-related quality of life (HRQoL), and depressive symptoms. The prevalence of UI in this sample was 26.9%. Women were more likely to report UI, as were those who were less physically active; used assistive ambulatory devices; and had depressive symptoms, greater medical comorbidity, worse physical performance, greater ADL impairment, worse cognitive function, and lower HRQoL. Multivariate logistic regression revealed that medical comorbidity was independently associated with higher rates of UI (odds ratio (OR)=1.66, 95% confidence interval (CI)=1.30-2.12), whereas better cognitive function (OR=0.73, 95% CI=0.57-0.93) and higher weighted physical activity scores (OR=0.77, 95% CI=0.60-0.98) were independently associated with lower rates of UI. UI is highly prevalent but not ubiquitous among community-residing older Latinos, suggesting that UI is not an inevitable consequence of aging. Future studies should examine whether interventions that decrease comorbidity and cognitive decline and increase physical activity improve continence status.
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Lee U, Nissim H, Le TX, Smith AL, Sarkisian C, Litwin MS, Raz S, Rodríguez LV, Maliski S, Anger JT. 486 THE VALUE OF A PATIENT-CENTERED CHRONIC CARE APPROACH TO TREATING OVERACTIVE BLADDER IN WOMEN. J Urol 2010. [DOI: 10.1016/j.juro.2010.02.561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Smith AL, Wein AJ. Recent advances in management of bladder overactivity. F1000 MEDICINE REPORTS 2010; 2. [PMID: 20948824 PMCID: PMC2948402 DOI: 10.3410/m2-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pharmacologic therapies, primarily antimuscarinic agents, have been the mainstay of treatment for overactive bladder. These drugs produce variable efficacy, a moderate rate of side effects, and rare occurrences of cure. The search for newer and better formulations and derivatives of this class of medication as well as novel therapies is ongoing and primarily fueled by the high prevalence of overactive bladder and the tremendous number of health care dollars spent on current therapy. Surgical options for overactive bladder have evolved slowly and are currently reserved for medical treatment failures and drug intolerance. This article will highlight the new drugs and therapies brought into clinical use for the treatment of overactive bladder over the last few years as well as a promising new agent in the advanced stages of development.
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Smith AL, Pareja R, Ramirez PT. Robotic radical hysterectomy. A literature review. MINERVA GINECOLOGICA 2009; 61:339-346. [PMID: 19745798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Advanced laparoscopic procedures are increasingly being used as an alternative to laparotomy in gynecologic surgery. Several reviews have been completed that examine the advantages and drawbacks of this technique. Robotic technology offers the promise of overcoming many of the shortcomings of laparoscopy, while preserving classic operative techniques. This review article summarizes some of the most recent literature provided in the arena of robotic assisted radical hysterectomy for the treatment of cervical or endometrial cancer.
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Smith AL, Kim JH, Staack A, Baxter C, Jeong YS, Rodriguez LV, Raz S. SUPRAMEATAL URETHROLYSIS WITH MARTIUS FLAP. J Urol 2009. [DOI: 10.1016/s0022-5347(09)62212-6] [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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Smith AL, Kim JH, Baxter C, Staack A, Rodriguez L, Raz S. URETHROVAGINAL FISTULA REPAIR WITH MARTIUS FLAP. J Urol 2009. [DOI: 10.1016/s0022-5347(09)62209-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Baxter C, Staack A, Kim JH, Smith AL, Rodriguez LV, Raz S. NOVEL RECTUS CROSSOVER TECHNIQUE FOR ENHANCING CONTINENCE IN CUTANEOUS URINARY DIVERSION. J Urol 2009. [DOI: 10.1016/s0022-5347(09)61564-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Anger JT, Khan A, Smith AL, Nissim HA, Le TX, Sarkisian CA, Maliski SL, Litwin MS, Raz S, Rodriguez LV. MISCONCEPTIONS AND MISCOMMUNICATION AMONG AGING WOMEN WITH OAB. J Urol 2009. [DOI: 10.1016/s0022-5347(09)61595-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Smith AL, Kim JH, Staack A, Baxter C, Rodriguez LV, Raz S. URODYNAMIC TRENDS IN THE FEMALE AGING POPULATION: DETRUSOR HYPERACTIVITY WITH IMPAIRED CONTRACTILITY, TWO CONDITIONS OR ONE? J Urol 2009. [DOI: 10.1016/s0022-5347(09)61682-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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113
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Kim JH, Smith AL, Raz S. Urinary fistulas: What does the evidence say? CURRENT BLADDER DYSFUNCTION REPORTS 2008. [DOI: 10.1007/s11884-008-0031-6] [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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Nguyen PKT, Smith AL, Reynolds KJ. A literature review of different pressure ulcer models from 1942-2005 and the development of an ideal animal model. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2008; 31:223-5. [PMID: 18946981 DOI: 10.1007/bf03179348] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The literature from 1942-2005 was reviewed in order to determine an inexpensive animal model which can closely mimic pressure ulcers seen in humans of varying ages, without the need for surgical procedures. Two animal models for producing pressure ulcers were found to be inexpensive: pigs to mimic pressure ulcers in young humans due to their fixed skin, and rats to mimic pressure ulcers in the elderly due to their loose skin. The methods which were found to be inexpensive, reproducible, non-invasive and easy to carry out without the need of a surgeon or specialist were the use of magnets for rat models and the use of a cast placed over a bony prominence for pig models.
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Smith AL, Raz S. Editorial comment on: Correction of erosion after suburethral sling insertion for stress incontinence: results and related sexual function. Eur Urol 2008; 56:377. [PMID: 18768250 DOI: 10.1016/j.eururo.2008.07.082] [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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Smith AL, Raz S. Editorial Comment. J Urol 2008. [DOI: 10.1016/j.juro.2008.01.232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Smith AL, Friesen VL. Differentiation of sympatric populations of the band-rumped storm-petrel in the Galapagos Islands: an examination of genetics, morphology, and vocalizations. Mol Ecol 2007; 16:1593-603. [PMID: 17402976 DOI: 10.1111/j.1365-294x.2006.03154.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In each of at least two locations within the Galapagos Islands, breeding band-rumped storm-petrels (Oceanodroma castro) form two distinct populations that use the same colony site at separate times of the year for reproduction. Temporal segregation of these populations raises the possibility that they are reproductively isolated and represent cryptic species. We examined variation in mitochondrial DNA, morphology, and vocalizations of storm-petrel populations nesting 6 months apart on the islet of Plaza Norte in the Galapagos. Seasonal populations displayed low but significant levels of differentiation in the mitochondrial control region, five morphological variables, and one feature of male vocalizations. Breeding populations appear to have been separated for approximately 1700 years. Given the recent divergence date and relatively high effective population sizes (4000-5600 females each), seasonal populations are unlikely to be in genetic equilibrium. As a result, the low divergence estimate probably reflects historical association and not contemporary genetic exchange. These populations are not sufficiently differentiated to be considered cryptic species. However, they are probably in the early stages of divergence. Consequently, we recommend that cool- and hot season populations on Plaza Norte be recognized as separate management units.
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Mucksavage P, Smith AL, Moy ML. The use of botulinum toxin in the treatment of refractory overactive bladder. OSTOMY/WOUND MANAGEMENT 2006; 52:28, 30, 32-3. [PMID: 17219700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
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Smith AL, Van Arsdalen K. Case Reports: Ureteroscopic Removal of Eroded Staples in Two Patients with History of Laparoscopic Surgery. J Endourol 2006; 20:659-62. [PMID: 16999620 DOI: 10.1089/end.2006.20.659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Complications from laparoscopically placed staples are rare. We present two patients with ureteral obstruction secondary to eroded staples. Each patient had a remote history of laparoscopic abdominal or pelvic surgery and was treated with endoscopic removal and short-term ureteral stenting. The clinical presentation and management are discussed.
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Beal RK, Wigley P, Powers C, Barrow PA, Smith AL. Cross-reactive cellular and humoral immune responses to Salmonella enterica serovars Typhimurium and Enteritidis are associated with protection to heterologous re-challenge. Vet Immunol Immunopathol 2006; 114:84-93. [PMID: 16935350 DOI: 10.1016/j.vetimm.2006.07.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 07/07/2006] [Accepted: 07/25/2006] [Indexed: 11/15/2022]
Abstract
Chickens infected with Salmonella enterica serovars Typhimurium (ST) and Enteritidis (SE) still represent a major source of human food poisoning via consumption of contaminated meat and eggs. Vaccination represents a sustainable approach to control Salmonella in the chicken and the serovar specificity of immunity has the potential to impact on the need for multivalent vaccines. The issue of cross-reactive immune responses and cross-serovar protection was examined in these experiments. Cellular and humoral immune responses were measured by antigen-specific ELISA and splenocyte proliferation assays during primary infections (with ST and SE) and during a second challenge with homologous or heterologous serovars. Primary infection with ST or SE induced strong lymphocyte proliferation and high levels of specific antibody (IgM, IgG and IgA) responses with substantial serovar cross-reactivity. The occurrence of high levels of splenocyte proliferation and strong antibody responses corresponded to the initiation of clearance with both ST and SE. Re-challenge of ST and SE infection-primed chickens with either serovar resulted in significant levels of protection (assessed by bacterial numbers and rate of clearance) with little difference between homologous or heterologous challenge schedules. Relatively low levels of antigen-specific splenocyte proliferation were detected during secondary infection, which may be caused by splenic T cells exiting to the gut. In contrast, the more rapid specific antibody responses (compared with primary infection controls) indicate the development of a secondary antigen-specific adaptive response. The substantial level of cross-protection between serovars and the level of antigenic cross-reactivity indicates the potential for single serovar live vaccines to protect against both group B and D salmonellae.
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Matsui EC, Diette GB, Krop EJM, Aalberse RC, Smith AL, Eggleston PA. Mouse allergen-specific immunoglobulin G4 and risk of mouse skin test sensitivity. Clin Exp Allergy 2006; 36:1097-103. [PMID: 16911366 DOI: 10.1111/j.1365-2222.2006.02534.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND High serum levels of cat-specific IgG and IgG4 are associated with protection against allergic sensitization to cat, but whether this association applies to other animal allergens remains unclear. OBJECTIVE To determine if high levels of mouse-specific IgG and IgG4 are associated with a decreased risk of mouse skin test sensitivity. METHODS Two hundred and sixty workers of a mouse facility underwent skin prick testing and completed a questionnaire. Serum levels of mouse-specific IgG and IgG4 were quantified by solid-phase antigen binding assays. Room air samples were collected and airborne Mus m 1 was quantified by ELISA. RESULTS Forty-nine participants had a positive skin prick test to mouse. Mouse-specific IgG was detected in 219 (84%) participants and IgG4 was detected in 72 (28%) participants. A detectable mouse-specific IgG4 level was associated with an increased risk of mouse skin test sensitivity (odds ratios (OR) 6.4, 95% confidence intervals (CI) 3.3-12.4). Mouse-specific IgG and IgG4 were both positively correlated with mouse allergen exposure (r(s)=0.31, P=0.0001, and r(s)=0.27, P=0.0006, respectively). The odds of skin test sensitivity peaked at moderate levels of IgG4, but decreased at the highest levels of mouse-specific IgG4. In contrast, the odds of skin test sensitivity increased monotonically with IgG levels. CONCLUSIONS A detectable level of mouse-specific IgG4 is associated with an increased risk of skin test sensitivity to mouse. However, the highest IgG4 levels appear to be associated with an attenuated risk of mouse skin test sensitivity, suggesting that induction of high levels of IgG4 through natural exposure may protect against the development of allergic sensitization.
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Abstract
The Eimeria species, causative agents of the disease coccidiosis, are genetically complex protozoan parasites endemic in livestock. Drug resistance remains commonplace among the Eimeria, and alternatives to chemotherapeutic control are being sought. Vaccines based upon live formulations of parasites are effective, but production costs are high, stimulating demand for a recombinant subunit vaccine. The identity of antigens suitable for inclusion in such vaccines remains elusive. Selection of immunoprotective antigens of the Eimeria species as vaccine candidates based upon recognition by the host immune system has been unsuccessful, obscured by the considerable number of molecules that are immunogenic but not immunoprotective. This is a common problem which characterizes work with most eukaryotic parasites. The identification of a selective criterion to directly access genetic loci that encode immunoprotective antigens of Eimeria maxima using a mapping strategy based upon parasite genetics, immune selection and DNA fingerprinting promises to revolutionize the process of antigen discovery. Linkage analyses of DNA markers amplified from populations of recombinant parasites defined by an ability to escape parent-specific deleterious selection by strain-specific immunity and chemotherapy has revealed four discrete regions within the E. maxima genome linked to escape from a protective immune response. These regions now form the basis of detailed study to identify antigens as candidates for inclusion in future vaccination strategies.
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Smith AL, Ferlise VJ, Rovner ES. Female urethral strictures: successful management with long-term clean intermittent catheterization after urethral dilatation. BJU Int 2006; 98:96-9. [PMID: 16831151 DOI: 10.1111/j.1464-410x.2006.06206.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To report our experience in the diagnosis and treatment of urethral stricture in women. PATIENTS AND METHODS A retrospective review of records and video-urodynamics identified women treated for urethral stricture between 1999 and 2004 at one institution by one surgeon. Urethral stricture was defined as a fixed anatomical narrowing between the bladder neck and distal urethra of <14 F preventing catheterization, and the diagnosis was confirmed by cysto-urethroscopy, and/or video-urodynamics. Women with a history of external beam radiotherapy to the pelvis, or of gynaecological, urethral or bladder malignancy, were excluded, and the women had a urethral biopsy to exclude a malignant cause of the stricture. Initial treatment consisted of urethral dilatation to > or = 30 F. After a period of indwelling catheterization, the women were placed on clean intermittent self-catheterization (CISC) at least once daily, and monitored every 3-6 months. At each follow-up, the urethra was catheterized to exclude recurrence. American Urological Association (AUA) symptom scores were obtained at presentation and at the initial 3 month follow-up. RESULTS Seven women met the criteria for urethral stricture, and were followed for a mean (range) of 21 (6-34) months. All were initially maintained on daily CISC, and some were gradually reduced to weekly CISC for the duration of follow-up. No patient had a recurrent stricture while on CISC, and none has had a urethral reconstruction to manage their condition. AUA symptom scores improved in all of the women by a mean of 10.7 points. No complications related to catheterization were noted. CONCLUSION Urethral stricture is rare in women. Long-term CISC in these women is safe and effective, and can avoid the need for major reconstructive surgery.
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Matsui EC, Diette GB, Krop EJM, Aalberse RC, Smith AL, Curtin-Brosnan J, Eggleston PA. Mouse allergen-specific immunoglobulin G and immunoglobulin G4 and allergic symptoms in immunoglobulin E-sensitized laboratory animal workers. Clin Exp Allergy 2006; 35:1347-53. [PMID: 16238795 DOI: 10.1111/j.1365-2222.2005.02331.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND High levels of allergen-specific IgG have been associated with clinical efficacy in immunotherapy studies, but whether this antibody isotype is associated with clinical tolerance in the setting of environmental exposure remains unclear. OBJECTIVE To determine if mouse allergen-specific IgG (mIgG) and IgG4 (mIgG4) levels are associated with mouse-related symptoms among IgE-sensitized laboratory workers. METHODS Fifty-eight workers with either skin test or serologic evidence of IgE-mediated mouse sensitization were studied. Symptom data were obtained by a questionnaire. Serum levels of mouse-specific IgG, IgG4, and IgE were quantified by a solid-phase antigen-binding assay (IgG) and RAST (IgG4 and IgE), and the relationships between mouse-specific serologic responses and mouse-related symptoms were analysed. RESULTS Twenty-three (39.7%) participants reported mouse-related symptoms. Mouse-specific IgG and IgG4 levels were not associated with mouse-related symptoms among the study population as a whole. Among the 29 (50%) participants with detectable mouse-specific IgE (mIgE), higher mouse-specific IgG and IgG4 levels were associated with a decreased risk of symptoms, after adjusting for mIgE level (odds ratio (OR) 0.3, 95% confidence interval (CI): 0.1-1.4, and OR 0.3, 95% CI: 0.04-2.6, respectively). Higher levels of mIgG and mIgG4 remained associated with a decreased risk of symptoms after additional adjustment for sex and handling of mice (OR 0.1, 95% CI: 0.02-0.7, and OR 0.2, 95% CI: 0.02-2.1, respectively). Higher mIgG : IgE and mIgG4 : IgE ratios were also associated with a decreased risk of symptoms after adjusting for these confounders (OR 0.1, 95% CI: 0.02-0.7, and OR 0.2, 95% CI: 0.02-0.92, respectively). CONCLUSION Among workers with detectable mIgE, higher mIgG and mIgG4 levels are associated with a decreased risk of mouse-related symptoms. High serum levels of mIgG or mIgG4 may be markers for clinical tolerance among laboratory mouse workers with detectable mIgE, but these findings need to be confirmed in larger, prospective studies.
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Shirley MW, Blake D, White SE, Sheriff R, Smith AL. Integrating genetics and genomics to identify new leads for the control ofEimeriaspp. Parasitology 2005; 128 Suppl 1:S33-42. [PMID: 16454897 DOI: 10.1017/s0031182004006845] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Eimerian parasites display a biologically interesting range of phenotypic variation. In addition to a wide spectrum of drug-resistance phenotypes that are expressed similarly by many other parasites, theEimeriaspp. present some unique phenotypes. For example, unique lines ofEimeriaspp. include those selected for growth in the chorioallantoic membrane of the embryonating hens egg or for faster growth (precocious development) in the mature host. The many laboratory-derived egg-adapted or precocious lines also share a phenotype of a marked attenuation of virulence, the basis of which is different as a consequence of thein ovoorin vivoselection procedures used. Of current interest is the fact that some wild-type populations ofEimeria maximaare characterized by an ability to induce protective immunity that is strain-specific. The molecular basis of phenotypes that defineEimeriaspp. is now increasingly amenable to investigation, both through technical improvements in genetic linkage studies and the availability of a comprehensive genome sequence for the caecal parasiteE. tenella. The most exciting phenotype in the context of vaccination and the development of new vaccines is the trait of strain-specific immunity associated withE. maxima. Recent work in this laboratory has shown that infection of two inbred lines of White Leghorn chickens with the W strain ofE. maximaleads to complete protection to challenge with the homologous parasite, but to complete escape of the heterologous H strain, i.e. the W strain induces an exquisitely strain-specific protective immune response with respect to the H strain. This dichotomy of survival in the face of immune-mediated killing has been examined further and, notably, mating between a drug-resistant W strain and a drug-sensitive H strain leads to recombination between the genetic loci responsible for the specificity of protective immunity and resistance to the anticoccidial drug robenidine. Such a finding opens the way forward for genetic mapping of the loci responsible for the induction of protective immunity and integration with the genome sequencing efforts.
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