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Campbell KJ, Kwenda EP, Bozorgmehri S, Terry RS, Yeung LL. Penile Strangulation: Analysis of Postextrication Follow-Up, Sequelae, and a Review of Literature. Am J Mens Health 2024; 18:15579883231223366. [PMID: 38293721 PMCID: PMC10832435 DOI: 10.1177/15579883231223366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 11/14/2023] [Accepted: 11/22/2023] [Indexed: 02/01/2024] Open
Abstract
Numerous case reports exist on penile strangulation injuries and extrication methods; however, the care and long-term consequences of penile strangulation injuries have been under-reported. Our aim is to investigate the long-term outcomes and sequalae following penile strangulation injuries. The PubMed Medline database was searched using the keyword string "penile strangulation," "penis strangulation," and "constriction" for all studies reporting outcomes of published penile strangulation injuries. Articles were evaluated for follow-up after strangulation injury, strangulating agent, extricating agent, and sequelae of injury. Fifty-six studies resulted with reports of 100 cases of penile strangulation and extrication from January 2000 to December 2019. The mean patient age was 41 (range: 3-86) years. Twenty-four (24/100) cases reported sequalae following extrication. Follow-up ranged from 2 weeks to 7 years with median follow-up time in the 7- to 12-month grouping. Metal rings comprised 36% (36/100) of strangulation agents and 50% of reported incidents were attributed to sexual activity. To our knowledge, this is the only study focusing on long-term outcomes after penile strangulation. This review provides a summary of 56 studies that document penile strangulation injuries over the last 20 years. Although a wide array of penile strangulation injuries have been documented in the literature, reports lack secondary management and long-term outcomes after removal of the strangulation device. We recommend that providers report long-term penile strangulation outcomes for future urologic evaluations after extrication.
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Affiliation(s)
- Kevin J. Campbell
- Department of Urology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Elizabeth P. Kwenda
- Department of Urology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Shahab Bozorgmehri
- Department of Urology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Russell S. Terry
- Department of Urology, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Lawrence L. Yeung
- Department of Urology, College of Medicine, University of Florida, Gainesville, FL, USA
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2
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Whiles BB, Bird VG, Canales BK, DiBianco JM, Terry RS. Caution! AI Bot Has Entered the Patient Chat: ChatGPT Has Limitations in Providing Accurate Urologic Healthcare Advice. Urology 2023; 180:278-284. [PMID: 37467806 DOI: 10.1016/j.urology.2023.07.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/20/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023]
Abstract
OBJECTIVE To conduct the first study examining the accuracy of ChatGPT, an artificial intelligence (AI) chatbot, derived patient counseling responses based on clinical care guidelines in urology using a validated questionnaire. METHODS We asked ChatGPT a set of 13 urological guideline-based questions three times. Answers were evaluated for appropriateness and using Brief DISCERN (BD), a validated healthcare information assessment questionnaire. Data analysis included descriptive statistics and Student's t test (SAS Studio). RESULTS 60% (115/195) of ChatGPT responses were deemed appropriate. Variability existed between responses to the same prompt, with 25% of the 13 question sets having discordant appropriateness designations. The average BD score was 16.8 ± 3.59. Only 7 (54%) of 13 topics and 21 (54%) of 39 responses met the BD cut-off score of ≥16 to denote good-quality content. Appropriateness was associated with higher overall and Relevance domain scores (both P < .01). The lowest BD domain scores were for Source categories, since ChatGPT does not provide references by default. With prompting, 92.3% had ≥1 incorrect, misinterpreted, or nonfunctional citations. CONCLUSION While ChatGPT provides appropriate responses to urological questions more than half of the time, it misinterprets clinical care guidelines, dismisses important contextual information, conceals its sources, and provides inappropriate references. Chatbot models hold great promise, but users should be cautious when interpreting healthcare-related advice from existing AI models. Additional training and modifications are needed before these AI models will be ready for reliable use by patients and providers.
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Affiliation(s)
| | - Vincent G Bird
- Department of Urology, University of Florida, Gainesville, FL
| | | | - John M DiBianco
- Department of Urology, University of Florida, Gainesville, FL
| | - Russell S Terry
- Department of Urology, University of Florida, Gainesville, FL
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3
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Terry RS, Ho DS, Scialabba DM, Whelan PS, Qi R, Ketterman BT, Preminger GM, Zhong P, Lipkin ME. Comparison of Different Pulse Modulation Modes for Holmium:Yttrium-Aluminum-Garnet Laser Lithotripsy Ablation in a Benchtop Model. J Endourol 2022; 36:29-37. [PMID: 34269626 PMCID: PMC8785761 DOI: 10.1089/end.2021.0113] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Introduction: Manipulation of Holmium:Yttrium-Aluminum-Garnet laser parameters such as pulse energy (PE), frequency, and duration can impact laser lithotripsy ablation efficiency. In 2017, Lumenis introduced Moses™ Technology, which uses pulse modulation to enhance the delivery of energy from fiber to stone as well as to minimize stone retropulsion. Since the introduction of Moses Technology, other companies have brought additional pulse modulation concepts to market. The purpose of this in vitro study is to compare the pulse characteristics and stone ablation efficiency of Lumenis Moses Technology with Quanta's Vapor Tunnel™. Materials and Methods: Submerged BegoStone phantoms were systematically ablated using either the Lumenis Moses Pulse 120H or the Quanta Litho 100 clinical laser system. Two PEs (0.4 and 1 J), three fiber-stone standoff distances (SDs) (0.5, 1, 2 mm), and all available pulse duration and modulation modes for each laser were tested in combination. Fiber speed was adjusted to scan across the stone surface at either 1 or 10 pulses/mm to form single pulse craters or an ablation trough, respectively. Volumes of single craters and 1 mm trough segments were imaged and quantified using optical coherence tomography. Results: Ablation volumes decreased with decreasing PE and increasing SD. Statistically significant variability was seen between pulse types (PT) at every tested parameter set. Among pulse modulation modes, Moses Distance (MD) was superior at 0.5 mm in all testing and at 2 mm in trough testing. Vapor Tunnel (VT) was superior in 2 mm single crater testing. All modulated pulses performed similarly at 1 mm. Conclusions: In this benchtop model of laser lithotripsy, stone ablation was significantly impacted by PT. MD demonstrated superior or noninferior stone ablation at most tested parameters. VT maintained its efficacy the best as SD increased. Future work should focus on the mechanistic differences of these modes relative to other traditional laser pulse modes.
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Affiliation(s)
- Russell S. Terry
- Department of Urology, University of Florida College of Medicine, Gainesville, Florida, USA.,Address correspondence to: Russell S. Terry, MD, Department of Urology, University of Florida College of Medicine, 1600 SW Archer Road, Box 100247, Gainesville, FL 32610, USA
| | - Derek S. Ho
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Dominick M. Scialabba
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Patrick S. Whelan
- Division of Urologic Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Robert Qi
- Division of Urologic Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Glenn M. Preminger
- Division of Urologic Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Pei Zhong
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Michael E. Lipkin
- Division of Urologic Surgery, Duke University Medical Center, Durham, North Carolina, USA
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4
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Ho DS, Scialabba D, Terry RS, Ma X, Chen J, Sankin GN, Xiang G, Qi R, Preminger GM, Lipkin ME, Zhong P. The Role of Cavitation in Energy Delivery and Stone Damage During Laser Lithotripsy. J Endourol 2021; 35:860-870. [PMID: 33514285 DOI: 10.1089/end.2020.0349] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose: Although cavitation during laser lithotripsy (LL) contributes to the Moses effect, the impact of cavitation on stone damage is less clear. Using different laser settings, we investigate the role of cavitation bubbles in energy delivery and stone damage. Materials and Methods: The role of cavitation in laser energy delivery was characterized by using photodetector measurements synced with high-speed imaging for laser pulses of varying durations. BegoStone samples were treated with the laser fiber oriented perpendicularly in contact with the stone in water or in air to assess the impact of cavitation on crater formation. Crater volume and geometry were quantified by using optical coherence tomography. Further, the role of cavitation in stone damage was elucidated by treatment in water with the fiber oriented parallel to the stone surface and by photoelastic imaging. Results: Longer pulse durations resulted in higher energy delivery but smaller craters. Stones treated in water resulted in greater volume, wider yet shallower craters compared with those treated in air. Stones treated with the parallel fiber showed crater formation after 15 pulses, confirmed by high-speed imaging of the bubble collapse with the resultant stress field captured by photoelastic imaging. Conclusions: Despite improved energy delivery, the longer pulse mode produced smaller crater volume, suggesting additional processes secondary to photothermal ablation are involved in stone damage. Our critical observations of the difference in stone damage treated in water vs in air, combined with the crater formation by parallel fiber, suggest that cavitation is a contributor to stone damage during LL.
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Affiliation(s)
- Derek S Ho
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Dominick Scialabba
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Russell S Terry
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Xiaojian Ma
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA.,Department of Research and Development, China Academy of Launch Vehicle Technology, Beijing, China
| | - Junqin Chen
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Georgy N Sankin
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Gaoming Xiang
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Robert Qi
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Glenn M Preminger
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael E Lipkin
- Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina, USA
| | - Pei Zhong
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
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Abstract
Introduction: Single-use flexible ureteroscopes are an increasingly popular alternative to reusable ureteroscopes. In this study, we performed a benchtop examination of the physical and optical properties of the new Dornier Axis™ (Webling, Germany) single-use ureteroscope. Methods: Ten new, never-used Dornier Axis ureteroscopes were assessed for optical performance, maximal tip deflection, and irrigation flow rate with an empty working channel and with insertion of 200 and 365 μm laser fibers, and a 1.9F nitinol basket. All ureteroscopes were then fully deflected 100 times in each direction, and maximal deflection angles were re-measured with and without instruments in the working channel. All measurements were performed in duplicate. In vitro optical testing for resolution, image distortion, and depth of field was performed and compared vs the LithoVue™ (Boston Scientific, Marlborough, MA) single-use ureteroscope. Statistical analyses using paired Wilcoxon rank-sum tests and Kruskal-Wallis multiple-group comparison tests were performed in R. Results: Median maximal deflection angles exceeded 300° in both directions before and after 100 full deflection cycles for all groups except the 365 μm laser fiber group. After 100 deflection cycles, there was no change in the majority of working instruments, except a decrease in upward flexion with an empty channel and 200 μm Moses™ laser fiber, and downward flexion with 200 μm Flexiva™ laser fiber (all <10°). After excluding the 365 μm fiber, there was no difference in multi-group comparison for upward and downward flexion pre- and post-cycling. Median flow rate through an empty channel was 48.0 mL/min, and it decreased significantly with all used instruments (p < 0.001). Compared with the LithoVue, the Axis demonstrated superior resolution at all tested distances and less distortion. Conclusions: The new Dornier Axis single-use ureteroscope demonstrates excellent tip deflection, which remains unchanged after 100 manual flexions in each direction. The Axis also demonstrates superior optical performance compared with the LithoVue in benchtop testing.
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Affiliation(s)
- Patrick Whelan
- Division of Urology, Duke University Medical Center, Durham, North Carolina, USA
| | - Russell S Terry
- Division of Urology, Duke University Medical Center, Durham, North Carolina, USA
| | - Robert Qi
- Division of Urology, Duke University Medical Center, Durham, North Carolina, USA
| | - Brian Ketterman
- Duke University School of Medicine, Durham, North Carolina, USA
| | - Glenn M Preminger
- Division of Urology, Duke University Medical Center, Durham, North Carolina, USA
| | - Michael E Lipkin
- Division of Urology, Duke University Medical Center, Durham, North Carolina, USA
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Terry RS, Preminger GM. Metabolic evaluation and medical management of staghorn calculi. Asian J Urol 2019; 7:122-129. [PMID: 32257805 PMCID: PMC7096691 DOI: 10.1016/j.ajur.2019.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/10/2019] [Accepted: 10/01/2019] [Indexed: 11/24/2022] Open
Abstract
Staghorn renal calculi are large renal calculi that occupy nearly the entirety of the renal collecting system. They may be composed of metabolic or infection stone types. They are often associated with specific metabolic defects. Infection stones are associated with urease-producing bacterial urinary tract infections. The ideal treatment for staghorn calculi is maximal surgical removal. However, some patients are either unwilling or unable to proceed with that modality of treatment, and therefore other management must be used. One such technique is the metabolic evaluation with directed medical management. Based on contemporary evidence that the majority of staghorn stones are metabolic in etiology, and furthermore that even infection stones are usually associated with metabolic abnormalities, metabolic evaluation with directed medical management is recommended for all staghorn stone formers. The scientific basis of this recommendation is reviewed in the present work.
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Affiliation(s)
- Russell S Terry
- Duke Comprehensive Kidney Stone Center, Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA
| | - Glenn M Preminger
- Duke Comprehensive Kidney Stone Center, Division of Urologic Surgery, Duke University Medical Center, Durham, NC, USA
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7
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Otto BJ, Terry RS, Lutfi FG, Syed JS, Hamann HC, Gupta M, Bird VG. The Effect of Continued Low Dose Aspirin Therapy in Patients Undergoing Percutaneous Nephrolithotomy. J Urol 2018; 199:748-753. [DOI: 10.1016/j.juro.2017.10.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2017] [Indexed: 12/23/2022]
Affiliation(s)
- Brandon J. Otto
- Department of Urology, University of Florida College of Medicine, Gainesville, Florida
| | - Russell S. Terry
- Department of Urology, University of Florida College of Medicine, Gainesville, Florida
| | - Forat G. Lutfi
- University of Florida College of Medicine, Gainesville, Florida
| | - Jamil S. Syed
- University of Florida College of Medicine, Gainesville, Florida
| | | | - Mohit Gupta
- Department of Urology, University of Florida College of Medicine, Gainesville, Florida
| | - Vincent G. Bird
- Department of Urology, University of Florida College of Medicine, Gainesville, Florida
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8
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Hide G, Gerwash O, Morley EK, Williams RH, Hughes JM, Thomasson D, Elmahaishi MS, Elmahaishi KH, Terry RS, Smith JE. Does vertical transmission contribute to the prevalence of toxoplasmosis? Parassitologia 2007; 49:223-226. [PMID: 18689231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Toxoplasma gondii is a ubiquitous parasite with a widespread distribution both in terms of geographical and host range. Although the definitive host is the cat, it is also a major health hazard to domestic animals and humans. Three routes of transmission are recognised (infection from the cat, carnivory and congenital transmission). We aimed to assess the relative importance of congenital transmission, using sheep as a model system, due to the lack of carnivory. We report, using PCR as a diagnostic tool, that congenital transmission occurs with high frequency (69%). If transmission from oocysts was important in sheep, we would expect sheep reared under the same environmental conditions (i.e. a single farm) to have a random distribution of Toxoplasma infection. Using breeding records in conjunction with PCR, some families were found to have high Toxoplasma prevalence and abortion while others were free of Toxoplasma infection and abortion (P < 0.01). This supports the notion that Toxoplasma may be transmitted vertically. In humans, we conducted a similar study and showed that Toxoplasma was transmitted from mother to baby in 19.8% of cases. Vertical transmission in Toxoplasma may be more important than previously thought and this knowledge should be considered in any eradication strategies.
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MESH Headings
- Abortion, Veterinary/epidemiology
- Abortion, Veterinary/etiology
- Abortion, Veterinary/parasitology
- Abortion, Veterinary/prevention & control
- Animal Feed/parasitology
- Animals
- Cats
- DNA, Protozoan/blood
- Female
- Fetal Blood/parasitology
- Humans
- Infant, Newborn
- Infectious Disease Transmission, Vertical
- Parasitemia/epidemiology
- Parasitemia/parasitology
- Polymerase Chain Reaction
- Pregnancy
- Pregnancy Complications, Infectious/epidemiology
- Pregnancy Complications, Infectious/parasitology
- Pregnancy Complications, Infectious/veterinary
- Prevalence
- Sheep
- Sheep Diseases/congenital
- Sheep Diseases/epidemiology
- Sheep Diseases/prevention & control
- Sheep Diseases/transmission
- Species Specificity
- Toxoplasma/isolation & purification
- Toxoplasmosis, Animal/congenital
- Toxoplasmosis, Animal/epidemiology
- Toxoplasmosis, Animal/prevention & control
- Toxoplasmosis, Animal/transmission
- Toxoplasmosis, Congenital/blood
- Toxoplasmosis, Congenital/epidemiology
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Affiliation(s)
- G Hide
- Centre for Parasitology and Infectious Diseases, Biomedical Sciences Research Institute, University of Salford, Salford, M5 4WT, UK.
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9
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Hughes JM, Williams RH, Morley EK, Cook DAN, Terry RS, Murphy RG, Smith JE, Hide G. The prevalence of Neospora caninum and co-infection with Toxoplasma gondii by PCR analysis in naturally occurring mammal populations. Parasitology 2006; 132:29-36. [PMID: 16393351 DOI: 10.1017/s0031182005008784] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Revised: 07/26/2005] [Accepted: 07/27/2005] [Indexed: 11/06/2022]
Abstract
Neospora caninum and Toxoplasma gondii are closely related intracellular protozoan parasites associated with bovine and ovine abortion respectively. Little is known about the extent of Neospora/Toxoplasma co-infection in naturally infected populations of animals. Using nested PCR techniques, based on primers from the Nc5 region of N. caninum and SAG1 for T. gondii, the prevalence of N. caninum and its co-infection with T. gondii were investigated in populations of Mus domesticus, Rattus norvegicus and aborted lambs (Ovis aries). A low frequency of infection with N. caninum was detected in the Mus domesticus (3%) and Rattus norvegicus (4.4%) populations. A relatively high frequency of infection with N. caninum was detected in the brains of aborted lambs (18.9%). There was no significant relationship between N. caninum and T. gondii co-infection. Investigation of the tissue distribution of Neospora, in aborted lambs, showed that Neospora could not be detected in tissues other than brain and this was in contrast to Toxoplasma where the parasite could be frequently detected in a range of tissues.
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Affiliation(s)
- J M Hughes
- Centre for Parasitology, Molecular Epidemiology and Ecology, Biosciences Research Institute, School of Environment and Life Sciences, University of Salford, Salford M5 4WT
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10
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Fielding NJ, MacNeil C, Robinson N, Dick JTA, Elwood RW, Terry RS, Ruiz Z, Dunn AM. Ecological impacts of the microsporidian parasite Pleistophora mulleri on its freshwater amphipod host Gammarus duebeni celticus. Parasitology 2005; 131:331-6. [PMID: 16178354 DOI: 10.1017/s0031182005007754] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The microsporidian parasite, Pleistophora mulleri, infects the abdominal muscle of the freshwater amphipod Gammarus duebeni celticus. We recently showed that P. mulleri infection was associated with G. d. celticus hosts being more vulnerable to predation by the invasive amphipod Gammarus pulex. Parasitized G. d. celticus also had a reduced ability to prey upon other co-occurring amphipods. We suggested the parasite may have pervasive influences on host ecology and behaviour. Here, we examine the association between P. mulleri parasitism and parameters influencing individual host fitness, behaviour and interspecific interactions. We also investigate the relationship between parasite prevalence and host population structure in the field. In our G. d. celticus study population, P. mulleri prevalence was strongly seasonal, ranging from 8.5% in summer to 44.9% in winter. The relative abundance of hosts with the heaviest parasite burden increased during summer, which coincided with high host mortality, suggesting that parasitism may regulate host abundance to some degree. Females were more likely to be parasitized than males and parasitized males were paired with smaller females than unparasitized males. Parasitism was associated with reduction in the host's activity level and reduced both its predation on the isopod Asellus aquaticus and aggression towards precopula pairs of the invasive G. pulex. We discuss the pervasive influence of this parasite on the ecology of its host.
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Affiliation(s)
- N J Fielding
- School of Biology and Biochemistry, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, N. Ireland, UK
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Morley EK, Williams RH, Hughes JM, Terry RS, Duncanson P, Smith JE, Hide G. Significant familial differences in the frequency of abortion and Toxoplasma gondii infection within a flock of Charollais sheep. Parasitology 2005; 131:181-5. [PMID: 16145934 DOI: 10.1017/s0031182005007614] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A study was carried out to investigate the frequencies of abortion and congenital Toxoplasma gondii infection within 27 families (765 individuals) of a pedigree Charollais sheep flock maintained on a working farm in Worcestershire, UK, since 1992. Pedigree lambing records were analysed to establish the frequency of abortion for each family. The frequency of congenital infection was determined for each family by PCR analysis of tissue samples taken from newborn lambs. A total of 155 lambs were tested for congenital T. gondii infection, which were all born during the study period 2000–2003. Significant differences in the frequency of abortion between sheep families within this flock were observed with frequencies ranging between 0% and 48% (P<0·01). Significantly different infection frequencies with T. gondii were also observed for different families and ranged between 0% and 100% (P<0·01). Although the actual cause of each abortion was not verified, a highly significant positive correlation was found to exist between the frequency of abortion and the frequency of T. gondii infection in the same families (P<0·01). The data presented here raise further questions regarding the significance of congenital transmission of T. gondii within sheep populations, the possible successive vertical transmission of T. gondii within families of sheep, and the potential role of inherited genetic susceptibility to abortion with respect to T. gondii infection. This work invites further study into the epidemiology of ovine toxoplasmosis and may have implications for sheep husbandry methods in the future.
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Affiliation(s)
- E K Morley
- Centre for Parasitology, Molecular Epidemiology and Ecology Biosciences Research Institute, School of Environment and Life Sciences, University of Salford, Salford, UK
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Williams RH, Morley EK, Hughes JM, Duncanson P, Terry RS, Smith JE, Hide G. High levels of congenital transmission of Toxoplasma gondii in longitudinal and cross-sectional studies on sheep farms provides evidence of vertical transmission in ovine hosts. Parasitology 2005; 130:301-7. [PMID: 15796013 DOI: 10.1017/s0031182004006614] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Recent research suggests that vertical transmission may play an important role in sustaining Toxoplasma gondii infection in some species. We report here that congenital transmission occurs at consistently high levels in pedigree Charollais and outbred sheep flocks sampled over a 3-year period. Overall rates of transmission per pregnancy determined by PCR based diagnosis, were consistent over time in a commercial sheep flock (69%) and in sympatric (60%) and allopatric (41%) populations of Charollais sheep. The result of this was that 53.7 % of lambs were acquiring an infection prior to birth: 46.4% of live lambs and 90.0% of dead lambs (in agreement with the association made between T. gondii and abortion). No significant differences were observed between lamb sexes. Although we cannot distinguish between congenital transmission occurring due to primary infection at pregnancy or reactivation of chronic infection during pregnancy, our observations of consistently high levels of congenital transmission over successive lambings favour the latter.
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Affiliation(s)
- R H Williams
- Centre for Parasitology, Molecular Epidemiology and Ecology, Bioscience Research Institute, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK
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13
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Morris DJ, Terry RS, Ferguson KB, Smith JE, Adams A. Ultrastructural and molecular characterization of Bacillidium vesiculoformis n. sp. (Microspora: Mrazekiidae) in the freshwater oligochaete Nais simplex (Oligochaeta: Naididae). Parasitology 2004; 130:31-40. [PMID: 15700755 DOI: 10.1017/s0031182004006286] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The development of a new species, Bacillidium vesiculoformis n. sp. (Microspora, Mrazekiidae), is described from the freshwater oligochaete Nais simplex (Oligochaeta, Naididae). Initial stages of parasite development consist of a monokaryotic merogony within a haemocyte of the intestinal blood sinus. The resulting hypertrophied haemocyte is attached to the chloragocytes of the sinus by fine cytoplasmic extensions with the sinus around the cell becoming greatly enlarged. The meronts within the haemocyte form diplokaryotic sporonts that undergo sporogenesis directly within the cytoplasm of the host cell. The infected cell becomes packed with spores and developmental stages, causing it dramatically to increase in size, eventually rupturing the oligochaete and cell. Sporogony appears to be disporoblastic. Released spores were observed to have an adhesive quality. Transmission studies conducted with mature spores failed to transmit the parasite horizontally although vertical transmission was observed. Phylogenetic analysis of the parasite demonstrated that B. vesiculoformis clustered with microsporidian parasites of bryozoa and two other microsporidians, Janacekia debaiseuxi and an unidentified Bacillidium sp.
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Affiliation(s)
- D J Morris
- Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK.
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Sokolova YY, Dolgikh VV, Morzhina EV, Nassonova ES, Issi IV, Terry RS, Ironside JE, Smith JE, Vossbrinck CR. Establishment of the new genus Paranosema based on the ultrastructure and molecular phylogeny of the type species Paranosema grylli Gen. Nov., Comb. Nov. (Sokolova, Selezniov, Dolgikh, Issi 1994), from the cricket Gryllus bimaculatus Deg. J Invertebr Pathol 2004; 84:159-72. [PMID: 14726239 DOI: 10.1016/j.jip.2003.10.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The ultrastructure of the microsporidian parasite Nosema grylli, which parasitizes primarily fat body cells and haemocytes of the cricket Gryllus bimaculatus (Orthoptera, Gryllidae) is described. All observed stages (meront, meront/sporont transitional stage ("second meront"), sporont, sporoblast, and spore) are found in direct contact with the host cell cytoplasm. Nuclei are diplokaryotic during almost all stages of the life cycle, but a brief stage with one nucleus containing an abundance of electron-dense material is observed during a "second merogony." Sporogony is disporous. Mature spores are ovocylindrical in shape and measure 4.5+/-0.16micromx2.2+/-0.07 microm (n=10) on fresh smears and 3.3+/-0.06 micromx1.4+/-0.07 microm (n=10) on ultrathin sections. Spores contain 15-18 coils of an isofilar polar filament arranged in one or two layers. Comparative phylogenetic analysis using rDNA shows N. grylli to be closely related to another orthopteran microsporidian, Nosema locustae, and to Nosema whitei from the confused flour beetle, Tribolium confusum. Antonospora scoticae, a parasite of the communal bee Andrena scotica, is a sister taxon to these three Nosema species. The sequence divergence and morphological traits clearly separate this group of "Nosema" parasites from the "true" Nosema clade containing Nosema bombycis. We therefore propose to change the generic name of N. grylli and its close relative N. locustae to Paranosema n. comb. We leave N. whitei in former status until more data on fine morphology of the species are obtained.
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Affiliation(s)
- Y Y Sokolova
- All-Russian Institute for Plant Protection, St. Petersburg, Russia.
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15
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Abstract
Our current understanding of congenital transmission of Toxoplasma gondii from ewe to lamb dictates that infection frequently results in abortion and the death of the developing foetus, that the birth of live infected lambs occurs rarely and that the cat is the predominant source of infection in ewes. Using direct polymerase chain reaction detection of T. gondii, we report high levels of congenital transmission occurring in a commercially managed sheep flock. We sampled foetal-derived placental tissue and tissues from aborted lambs and showed that congenital transmission was detected in these tissues from 61% of all pregnancies. Where pregnancies resulted in the death of one or more lambs, T. gondii was detected in the lamb tissue for all but one of 18 (94%) pregnancies. Of the successful pregnancies resulting in the birth of live lambs we were able to detect T. gondii in foetal-derived placental tissue from 37 of 70 (42%) pregnancies. These results show that congenital transmission is occurring in a high percentage of lambings including normal healthy lambings, at this farm, suggesting that this route of transmission from generation to generation may be much more significant than that reported previously. These results may have implications for sheep husbandry and future epidemiological studies of T. gondii.
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Affiliation(s)
- P Duncanson
- Centre for Molecular Epidemiology and Ecology, School of Environment and Life Sciences, University of Salford, Salford M5 4WT, UK
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16
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Abstract
The microsporidia are an ancient and diverse group of protists which have many unusual characteristics. These include prokaryotic-like 70s ribosomes, enclosed nuclear division, a lack of mitochondria and complex life cycles which frequently involve vertical transmission. This use of vertical transmission is unparalleled by other protists and is seen only among bacterial endosymbionts and sex ratio distorters and in host cell organelles. Transovarially transmitted microsporidia can have unusual and profound effects on host population sex ratios. We here consider the mechanisms of transovarial transmission and its implications for parasite evolution. We review parasite/host relationships and the evolution of virulence under transovarial transmission and consider the implications of these parasites for host ecology and evolution.
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Affiliation(s)
- A M Dunn
- School of Biology, University of Leeds, UK
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17
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Terry RS, Smith JE, Duncanson P, Hide G. MGE-PCR: a novel approach to the analysis of Toxoplasma gondii strain differentiation using mobile genetic elements. Int J Parasitol 2001; 31:155-61. [PMID: 11239935 DOI: 10.1016/s0020-7519(00)00158-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The position of mobile genetic elements (MGE) within eukaryotic genomes is often highly variable and we have exploited this phenomenon to develop a novel approach to strain differentiation in Toxoplasma gondii. Two PCR based strategies were designed in which specific primers were used to amplify T. gondii MGE's revealing information on element size and positional variation. The first PCR strategy involved the use of a standard two primer PCR while the second strategy used a single specific primer in a step-up PCR protocol. This approach was applied to T. gondii reference strains which were either acute virulent or avirulent to mice. The use of a standard two primer PCR reaction revealed the presence of a virulence related marker in which all avirulent strains possessed an additional 688 bp band. The single primer PCR strategy demonstrated that all virulent strains had identical banding patterns suggesting invariance within this group of strains. However, all avirulent strains had different banding patterns indicating the presence of a number of individual lineages within this group. The applicability and sensitivity of MGE-PCR in epidemiological studies was demonstrated by direct amplification of T. gondii from sheep tissue samples. All sheep isolates, tested in this way, gave identical banding patterns suggesting the presence of an endemic Toxoplasma strain on this farm.
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Affiliation(s)
- R S Terry
- Centre for Molecular Epidemiology and Ecology, Division of Biological Sciences, University of Salford, M5 4WT, Salford, UK
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Terry RS, Smith JE, Bouchon D, Rigaud T, Duncanson P, Sharpe RG, Dunn AM. Ultrastructural characterisation and molecular taxonomic identification of Nosema granulosis n. sp., a transovarially transmitted feminising (TTF) microsporidium. J Eukaryot Microbiol 1999; 46:492-9. [PMID: 10519217 DOI: 10.1111/j.1550-7408.1999.tb06066.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel microsporidian parasite is described, which infects the crustacean host Gammarus duebeni. The parasite was transovarially transmitted and feminised host offspring. The life cycle was monomorphic with three stages. Meronts were found in host embryos, juveniles, and in the gonadal tissue of adults. Sporoblasts and spores were restricted to the gonad. Sporogony was disporoblastic giving rise to paired sporoblasts, which then differentiated to form spores. Spores were not found in regular groupings and there was no interfacial envelope. Spores were approximately 3.78 x 1.22 microns and had a thin exospore wall, a short polar filament, and an unusual granular polaroplast. All life cycle stages were diplokaryotic. A region from the parasite small subunit ribosomal RNA gene was amplified and sequenced. Phylogenetic analysis based on these data places the parasite within the genus Nosema. We have named the species Nosema granulosis based on the structure of the polaroplast.
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Affiliation(s)
- R S Terry
- School of Biology, University of Leeds, UK
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19
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Abstract
We investigated the segregation of an intracellular microsporidian parasite during host cell division. A time-course experiment was carried out to examine the distribution of parasites relative to host chromosomal DNA via light and electron microscopy. Fluorescent light microscopy and EM studies showed that the parasite lay in the perinuclear zone of the host cell during interphase and segregated to daughter cells at mitosis. At metaphase, the parasite was frequently closely associated with host microtubules and mitochondria. Electron-dense bridges were observed between the parasites and the host microtubules and also between host mitochondria and microtubules. The study suggests that both the parasite and the host cell organelles segregate in association with spindle microtubules.
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Affiliation(s)
- R S Terry
- School of Biology, University of Leeds, UK
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20
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Abstract
The amphipod Gammarus duebeni harbours several species of vertically transmitted microsporidian parasites. G. Duebeni were collected from 3 localities in the UK. Animals from Budle Bay, Northumberland, were infected with Octosporea effeminans, and those from Millport, Isle of Cumbrae and Fenham Flats, Northumberland were infected with microsporidia of the genus Nosema. We derived expected distributions of parasites per host embryonic cell by modelling parasite transmission as a multitype, Galton-Watson branching process. Parasite prevalence (proportion of females infected) was significantly heterogeneous among localities. Parasite burden in zygotes was much higher for females infected with Nosema than in animals infected with O. effeminans. There was no significant difference between localities in the number of Nosema in the zygotes. Comparison of models and data from 64-cell host embryos showed that the distributions of parasites per cell were consistent with the hypothesis that sorting of parasites into daughter cells is biased for at least 1 cell lineage. Host embryos infected with O. effeminans could expect to contain a growing number of parasites in each cell generation within such biased cell lineages; similar estimates for Nosema predict a decline in the number of parasites per cell within a biased lineage. We discuss the possibility that the 2 species of parasite may be employing different strategies in order to ensure transmission to the next host generation.
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Affiliation(s)
- A M Dunn
- School of Biology, University of Leeds, UK.
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21
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Abstract
The cellular distribution of a vertically transmitted, feminizing microsporidian was followed in its host Gammarus duebeni. In adult females the parasite was restricted to gonadal tissue, in particular primary and secondary follicle cells. Spores were diplokaryotic with a thin spore wall and a short polar filament, characteristics typical of 'early' spores involved in autoinfection. The diplokaryotic life-cycle, absence of spore groupings and of a pansporoblast membrane typify the genus Nosema. However, the unusual globular polaroplast of the spore and restriction of this stage to host ovarian tissue have not previously been described in Nosema. Sporogony occurred only in follicle cells adjacent to developing oocytes and was in synchrony with the process of vitellogenesis. Oocytes were infected after formation of intracellular connections with follicle cells but harboured only vegetative stages of the parasite. Parasites were associated with the perinuclear cytoplasm and, in developing embryos, segregated to daughter cells along the axis of the spindle. In juvenile animals there was no evidence of pathology linked with feminization and the parasite was found at low density in cells under the cuticle. The parasite is highly adapted to transovarial transmission with an efficient mechanism of oocyte infection and no evidence of pathology.
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Affiliation(s)
- R S Terry
- Department of Biology, University of Leeds, UK
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Abstract
The neurocybernetic prosthesis system (NCP) is an implantable, multiprogrammable pulse generator that delivers constant current electrical signals to the vagus nerve for the purpose of reducing the frequency and severity of epileptic seizures. The signals are delivered on a predetermined schedule, or may be initiated by the patient with an external magnet. The device is implanted in a subcutaneous pocket in the chest just below the clavicle, similar to pacemaker placement. The stimulation signal is transmitted from the prosthesis to the vagus nerve through a lead connected to an electrode which is a multi-turn silicone helix, with a platinum band on the inner turn of one helix. The prosthesis can be programmed with any IBM- compatible personal computer using NCP software and a programming wand.
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