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Goodell PB, Johansen PM, Bartels DW, Sherman SL, Amanatullah DF. Comparing Unicompartmental Knee Arthroplasty and High Tibial Osteotomy for Isolated Medial Compartment Knee Osteoarthritis. JBJS Rev 2023; 11:01874474-202303000-00004. [PMID: 36930742 DOI: 10.2106/jbjs.rvw.22.00127] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
» Both unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) allow for compartment-specific intervention on an arthritic knee joint that preserves bone stock and native soft tissue compared to a total knee arthroplasty (TKA). Both operations give a more natural feeling with native proprioception compared with a TKA. » HTO is better suited in patients who are younger (<55 years-of-age), have a body mass index (BMI) <30 kg/m2, high activity requirements, mechanical malalignment, asymmetric varus, isolated anterior cruciate ligament insufficiency, need for multiplanar correction, and a preference for joint preserving interventions. Recent data suggest that age (>55 years-of-age) should not solely contraindicate a HTO. » UKA may be chosen in patients who are older (>55 years-of-age), low activity requirements, have a BMI <40 kg/m2, severe osteoarthritis with significant joint space narrowing, acceptable coronal alignment, symmetric varus, and patient preference for arthroplasty.
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Affiliation(s)
- Parker B Goodell
- Department of Orthopaedic Surgery, University of California San Francisco, Fresno, California
| | - Phillip M Johansen
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, Florida
| | - Douglas W Bartels
- Department of Orthopaedic Surgery, Stanford University, Palo Alto, California
| | - Seth L Sherman
- Department of Orthopaedic Surgery, Stanford University, Palo Alto, California
| | - Derek F Amanatullah
- Department of Orthopaedic Surgery, Stanford University, Palo Alto, California
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Wilson HJ, Goodell PB, Kollmorgen RC. A Novel Radiographic Finding of Intracapsular Heterotopic Ossification: A Report of Two Cases. Cureus 2020; 12:e11372. [PMID: 33304704 PMCID: PMC7721073 DOI: 10.7759/cureus.11372] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Symptomatic heterotopic ossification (HO) is a complication of hip arthroscopy that occurs in less than 1% of cases. To our knowledge, there are no reported cases of symptomatic intracapsular HO. We present 2 patients with a radiographic finding associated with intracapsular HO. Both patients underwent revision hip arthroscopy and required capsular reconstruction due to void of the iliofemoral ligament following excision of HO. We believe this radiographic finding may be useful to hip preservationists as it may be associated with capsular deficiency necessitating capsular reconstruction upon revision hip arthroscopy.
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Affiliation(s)
- Holly J Wilson
- Research, University of California San Francisco, Fresno, Fresno, USA
| | - Parker B Goodell
- Orthopaedic Surgery, University of California San Francisco, Fresno, Fresno, USA
| | - Robert C Kollmorgen
- Hip Preservation and Sports Medicine, University of California San Francisco, Fresno, Fresno, USA
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Hecht G, Shelton TJ, Saiz AM, Goodell PB, Wolinsky P. CT-measurement predicts shortening of stable intertrochanteric hip fractures. J Orthop 2018; 15:952-956. [PMID: 30210200 DOI: 10.1016/j.jor.2018.08.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/25/2018] [Indexed: 11/30/2022] Open
Abstract
Purpose Intertrochanteric (IT) hip fractures can be treated with sliding hip screws (SHS) or cephalomedullary nails (CMN) based on the stability of the fracture. This stability is affected by the initial impaction of the fracture which can be difficult to assess. The aim of this paper is to develop specific pre-operative computed tomography (CT) measurements of IT fractures which are predictive of post-operative shortening. Methods A retrospective review was performed of 141 patients with AO/OTA 31A1 or 31A2 fracture patterns, who had pre-operative radiographs and CT scans, and who were treated with a SHS or a CMN. Pre-operative and post-operative imaging of IT fractures were analyzed for those fractures that shortened ≥15 mm post-fixation. Results 11 fractures shortened ≥15 mm with CMN being protective of shortening (6/36 SHS versus 5/105 CMN, p = 0.0268). A novel measurement made on the pre-operative CT scan called the cortical thin point (CTP) detected differences between patients with <15 mm and ≥15 mm of post-operative shortening for the SHS group (p = 0.0375). CTP was found to be a reliable predictor for post-operative shortening of ≥15 mm when a cutoff threshold of 9 mm was used in the SHS group (p = 0.0161). Conclusions Measuring the CTP is predictive of post-operative shortening after fixation of an IT fracture with a SHS. CMN fixation may be protective of shortening. Patients with a CTP of ≤9 mm are at risk for fracture site shortening of more than 15 mm when treated with a SHS.
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Affiliation(s)
- Garin Hecht
- Department of Orthopaedics and Sports Medicine, Harborview Medical Center, USA
| | | | | | | | - Philip Wolinsky
- Department of Orthopedics, University of California, Davis, USA
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Goodell PB, Bauer AS, Oishi S, Arner M, Laurell T, Taylor SL, James MA. Functional Assessment of Children and Adolescents with Symbrachydactyly: A Unilateral Hand Malformation. J Bone Joint Surg Am 2017; 99:1119-1128. [PMID: 28678125 PMCID: PMC5490334 DOI: 10.2106/jbjs.16.01283] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND We studied children and adolescents with symbrachydactyly to determine whether hand function depends on digit opposability and whether scores for function and quality-of-life measures differ from population norms. METHODS Participants were grouped on the basis of hand morphology: Group A lacked opposable digits, and Group B had ≥2 digits that were opposable. The groups were compared with each other and with norms with respect to pinch strength, the performance of bimanual activities and in-hand manipulation, and questionnaires regarding psychosocial status and the ability to perform activities of daily living (ADLs). Participants and parents also rated the appearance and function of the hand. RESULTS Pinch strength was higher for participants in Group B (4.1 compared with 2.4 kg; p = 0.008), but the groups did not differ with respect to the proportion of participants outside of pinch norms. Participants in Group B were more likely to actively use their affected hand to perform bimanual activities (p ≤ 0.0009), and to use normal or supination strategies to accomplish in-hand manipulation (p = 0.031). The groups did not differ in the proportion of ADLs rated "difficult" or "impossible," and both groups tested within normal limits for psychosocial function. Participants from both groups and their parents rated their satisfaction with hand appearance and function similarly high. CONCLUSIONS Participants with ≥2 opposable digits incorporated their hand better in bimanual activities and used more effective strategies to accomplish in-hand manipulation than those who did not. These groups reported no difference in the ability to perform ADLs or with psychosocial function, which was within the normal range. Children and adolescents with symbrachydactyly demonstrated and reported a high level of function in all domains of validated function tests. This study provides information to help parents of children with a unilateral hand malformation understand their child's potential function, and assist surgeons with recommending treatment. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
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Affiliation(s)
- Parker B. Goodell
- Department of Public Health Sciences, Division of Biostatistics (S.L.T), Department of Orthopaedic Surgery (M.A.J.), University of California, Davis, School of Medicine (P.B.G.), Sacramento, California
| | - Andrea S. Bauer
- Department of Orthopedic Surgery, Boston Children’s Hospital, Boston, Massachusetts,Harvard Medical School, Boston, Massachusetts
| | - Scott Oishi
- Charles E. Seay, Jr. Hand Center, Texas Scottish Rite Hospital for Children, Dallas, Texas
| | - Marianne Arner
- Department of Clinical Science and Education (M.A.), Department of Molecular Medicine and Surgery (T.L.), and Center of Molecular Medicine (T.L.), Karolinska Institutet, Stockholm, Sweden,Department of Hand Surgery (M.A. and T.L.), Södersjukhuset, Stockholm, Sweden
| | - Tobias Laurell
- Department of Clinical Science and Education (M.A.), Department of Molecular Medicine and Surgery (T.L.), and Center of Molecular Medicine (T.L.), Karolinska Institutet, Stockholm, Sweden,Department of Hand Surgery (M.A. and T.L.), Södersjukhuset, Stockholm, Sweden
| | - Sandra L. Taylor
- Department of Public Health Sciences, Division of Biostatistics (S.L.T), Department of Orthopaedic Surgery (M.A.J.), University of California, Davis, School of Medicine (P.B.G.), Sacramento, California
| | - Michelle A. James
- Department of Public Health Sciences, Division of Biostatistics (S.L.T), Department of Orthopaedic Surgery (M.A.J.), University of California, Davis, School of Medicine (P.B.G.), Sacramento, California,Department of Orthopaedic Surgery, Shriners Hospitals for Children-Northern California, Sacramento, California,E-mail address for M.A. James:
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Abstract
Background: Symbrachydactyly is a unilateral congenital hand malformation characterized by failure of formation of fingers and the presence of rudimentary digit nubbins. The management is variable and are investigated in this review. Methods: A detailed review of the literature was compiled into succinct clinically relevant categories. Results: Etiology, classification, non-surgical management, surgical intervention, and patient oriented outcomes are discussed. Conclusions: All interventions should prioritize realistic, evidence-supported appearance and functional gains. Studies of the baseline function and quality of life of children with symbrachydactyly would allow surgeons to better understand functional changes associated with various interventions and would help surgeons and parents to make the best treatment decisions.
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Affiliation(s)
| | - Andrea S. Bauer
- Shriners Hospital for Children Northern California, Sacramento, USA,Andrea S. Bauer, Boston Children’s Hospital 300 Longwood Avenue, HUN 213 Boston, MA 02115, USA.
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Abstract
Seymour fractures are open juxta-physeal fractures of the distal phalanx. A true lateral radiograph should be obtained for diagnosis, and treatment should include removal of the nail, irrigation and debridement of the fracture, and percutaneous Kirschner wire stabilization. Mallet fractures are more common in children than adults, and treatment is generally nonoperative for nondisplaced or minimally displaced fractures without volar subluxation of the distal phalanx; however, splinting compliance should be carefully assessed in younger populations. Phalangeal neck fractures have a limited potential to remodel and a propensity to redisplace. A true lateral radiograph will show displacement best; treatment is generally with percutaneous pinning. Open reduction should be avoided when possible because of the risk of osteonecrosis of the phalangeal condyles. The epidemiology of scaphoid fractures in children is changing, with waist fractures now the most common type. This may be due to an increase in body mass index (BMI) as well as high-level sports participation in today's pediatric population. Although the vast majority of acute scaphoid fractures can be treated successfully with cast immobilization, children who present with established nonunions should be offered open reduction and internal fixation as the primary treatment.
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Affiliation(s)
- Parker B Goodell
- UC Davis School of Medicine, 2101A Education Building, 4610 X Street, Sacramento, CA 95817
| | - Andrea Bauer
- Boston Children's Hospital, HUN 213, 300 Longwood Avenue, Boston, MA 02115
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Polage CR, Gyorke CE, Kennedy MA, Leslie JL, Chin DL, Wang S, Nguyen HH, Huang B, Tang YW, Lee LW, Kim K, Taylor S, Romano PS, Panacek EA, Goodell PB, Solnick JV, Cohen SH. Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era. JAMA Intern Med 2015; 175:1792-801. [PMID: 26348734 PMCID: PMC4948649 DOI: 10.1001/jamainternmed.2015.4114] [Citation(s) in RCA: 406] [Impact Index Per Article: 45.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
IMPORTANCE Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision making and public health reporting. Molecular tests are increasingly used to diagnose C difficile infection (CDI), but many molecular test-positive patients lack toxins that historically defined disease, making it unclear if they need treatment. OBJECTIVE To determine the natural history and need for treatment of patients who are toxin immunoassay negative and polymerase chain reaction (PCR) positive (Tox-/PCR+) for CDI. DESIGN, SETTING, AND PARTICIPANTS Prospective observational cohort study at a single academic medical center among 1416 hospitalized adults tested for C difficile toxins 72 hours or longer after admission between December 1, 2010, and October 20, 2012. The analysis was conducted in stages with revisions from April 27, 2013, to January 13, 2015. MAIN OUTCOMES AND MEASURES Patients undergoing C difficile testing were grouped by US Food and Drug Administration-approved toxin and PCR tests as Tox+/PCR+, Tox-/PCR+, or Tox-/PCR-. Toxin results were reported clinically. Polymerase chain reaction results were not reported. The main study outcomes were duration of diarrhea during up to 14 days of treatment, rate of CDI-related complications (ie, colectomy, megacolon, or intensive care unit care) and CDI-related death within 30 days. RESULTS Twenty-one percent (293 of 1416) of hospitalized adults tested for C difficile were positive by PCR, but 44.7% (131 of 293) had toxins detected by the clinical toxin test. At baseline, Tox-/PCR+ patients had lower C difficile bacterial load and less antibiotic exposure, fecal inflammation, and diarrhea than Tox+/PCR+ patients (P < .001 for all). The median duration of diarrhea was shorter in Tox-/PCR+ patients (2 days; interquartile range, 1-4 days) than in Tox+/PCR+ patients (3 days; interquartile range, 1-6 days) (P = .003) and was similar to that in Tox-/PCR- patients (2 days; interquartile range, 1-3 days), despite minimal empirical treatment of Tox-/PCR+ patients. No CDI-related complications occurred in Tox-/PCR+ patients vs 10 complications in Tox+/PCR+ patients (0% vs 7.6%, P < .001). One Tox-/PCR+ patient had recurrent CDI as a contributing factor to death within 30 days vs 11 CDI-related deaths in Tox+/PCR+ patients (0.6% vs 8.4%, P = .001). CONCLUSIONS AND RELEVANCE Among hospitalized adults with suspected CDI, virtually all CDI-related complications and deaths occurred in patients with positive toxin immunoassay test results. Patients with a positive molecular test result and a negative toxin immunoassay test result had outcomes that were comparable to patients without C difficile by either method. Exclusive reliance on molecular tests for CDI diagnosis without tests for toxins or host response is likely to result in overdiagnosis, overtreatment, and increased health care costs.
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Affiliation(s)
- Christopher R Polage
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento2Division of Infectious Diseases, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento
| | - Clare E Gyorke
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento
| | - Michael A Kennedy
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento
| | - Jhansi L Leslie
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento3Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor
| | - David L Chin
- Center for Healthcare Policy and Research, University of California Davis, Sacramento
| | - Susan Wang
- Department of Pathology and Laboratory Medicine, University of California Davis School of Medicine, Sacramento5Yolo County Health Department, Woodland, California
| | - Hien H Nguyen
- Division of Infectious Diseases, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento
| | - Bin Huang
- Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, New York7Department of Clinical Laboratory, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yi-Wei Tang
- Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, New York8Weill Medical College of Cornell University, New York, New York
| | - Lenora W Lee
- Division of Infectious Diseases, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento
| | - Kyoungmi Kim
- Division of Biostatistics, Department of Public Health Sciences, University of California Davis School of Medicine, Sacramento
| | - Sandra Taylor
- Division of Biostatistics, Department of Public Health Sciences, University of California Davis School of Medicine, Sacramento
| | - Patrick S Romano
- Center for Healthcare Policy and Research, University of California Davis, Sacramento10Division of General Medicine, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento11Division of General Pediatrics, Department
| | - Edward A Panacek
- Department of Emergency Medicine, University of California Davis School of Medicine, Sacramento
| | - Parker B Goodell
- Department of Emergency Medicine, University of California Davis School of Medicine, Sacramento
| | - Jay V Solnick
- Division of Infectious Diseases, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento13Department of Medical Microbiology and Immunology, University of California Davis School of Medicine, Sacramento
| | - Stuart H Cohen
- Division of Infectious Diseases, Department of Internal Medicine, University of California Davis School of Medicine, Sacramento
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Marsden CD, Cornel A, Lee Y, Sanford MR, Norris LC, Goodell PB, Nieman CC, Han S, Rodrigues A, Denis J, Ouledi A, Lanzaro GC. An analysis of two island groups as potential sites for trials of transgenic mosquitoes for malaria control. Evol Appl 2013; 6:706-20. [PMID: 23789035 PMCID: PMC3684749 DOI: 10.1111/eva.12056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 01/13/2013] [Indexed: 11/29/2022] Open
Abstract
Considerable technological advances have been made towards the generation of genetically modified mosquitoes for vector control. In contrast, less progress has been made towards field evaluations of transformed mosquitoes which are critical for evaluating the success of, and hazards associated with, genetic modification. Oceanic islands have been highlighted as potentially the best locations for such trials. However, population genetic studies are necessary to verify isolation. Here, we used a panel of genetic markers to assess for evidence of genetic isolation of two oceanic island populations of the African malaria vector, Anopheles gambiae s.s. We found no evidence of isolation between the Bijagós archipelago and mainland Guinea-Bissau, despite separation by distances beyond the known dispersal capabilities of this taxon. Conversely, the Comoros Islands appear to be genetically isolated from the East African mainland, and thus represent a location worthy of further investigation for field trials. Based on assessments of gene flow within and between the Comoros islands, the island of Grande Comore was found to be genetically isolated from adjacent islands and also exhibited local population structure, indicating that it may be the most suitable site for trials with existing genetic modification technologies.
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Affiliation(s)
- Clare D Marsden
- Vector Genetics Laboratory, Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, CA, USA
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Ogallo JL, Goodell PB, Eckert J, Roberts PA. Evaluation of NemX, a New Cultivar of Cotton with High Resistance to Meloidogyne incognita. J Nematol 1997; 29:531-537. [PMID: 19274190 PMCID: PMC2619803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The level of resistance to root-knot nematode, Meloidogyne incognita, in NemX, a new cultivar of the Acala-type upland cotton, was evaluated in relation to four resistant breeding lines (N6072, N8577, N901, and N903) and four susceptible cultivars (Maxxa, SJ2, Royale, and Prema). In growth pouch tests, an average of only 4 nematode egg masses was produced on roots of NemX or the resistant lines, compared to a significantly higher average of 21 on the susceptible cultivars. In pot tests, the nematode reproduction factor (RF = Pf/Pi) in NemX and the resistant lines averaged 0.7, compared to a significantly higher average of 10 on the susceptible cultivars. Root galling in NemX or other resistant cotton averaged 15%, compared to 74% on the susceptible cultivars, in either pot or field tests. In plots with low levels of nematode infestation (Pi </= 150 second-stage juveniles [J2]/500 g soil), lint yield of NemX averaged 1,370 kg/ha and was less than the yield of susceptible Maxxa (1,450 k g /h a ). However, in plots with medium or high levels of nematode infestation (Pi = 151-300 or >300 J2/500 g soil, respectively), yields of NemX decreased only slightly and averaged 1,300 or 1,050 kg/ha, respectively, whereas yields of Maxxa were severely reduced to 590 or 503 kg/ha, respectively. Fusarium wih symptoms were observed on both NemX and Maxxa, and percent occurrence increased with increasing preplant nematode density. In plots with the highest nematode densities, 22% of NemX and 65% of Maxxa plants were wilted. NemX was highly effective against five M. incognita isolates and moderately effective against a sixth isolate that had been exposed to resistant cotton over several seasons. These results showed that NemX is as resistant to M. incognita as the four breeding lines, and much more resistant than the tested susceptible cultivars of cotton.
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Devay JE, Gutierrez AP, Pullman GS, Wakeman RJ, Garber RH, Jeffers DP, Smith SN, Goodell PB, Roberts PA. Inoculum Densities of Fusarium oxysporum f. sp. vasinfectum and Meloidogyne incognita in Relation to the Development of Fusarium Wilt and the Phenology of Cotton Plants (Gossypium hirsutum). Phytopathology 1997; 87:341-346. [PMID: 18945178 DOI: 10.1094/phyto.1997.87.3.341] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Development of Fusarium wilt in upland cotton (Gossypium hirsutum) usually requires infections of plants by both Meloidogyne incognita and Fusarium oxysporum f. sp. vasinfectum. In this study, the soil densities of M. incognita and F. oxysporum f. sp. vasinfectum and the incidence of Fusarium wilt in three field sites were determined in 1982-1984. Multiple regression analysis of percent incidence of Fusarium wilt symptoms on population densities of M. incognita and F. oxysporum f. sp. vasinfectum yielded a significant fit (R (2) = 0.64) only on F. oxysporum f. sp. vasinfectum. Significant t-values for slope were also obtained for the interaction of M. incognita and F. oxysporum f. sp. vasinfectum, but densities of M. incognita and F. oxysporum f. sp. vasinfectum were also related on a log(10) scale. The physiological time of appearance of first foliar symptoms of Fusarium wilt, based on a degree-days threshold of 11.9 degrees C (53.5 degrees F), was used as a basis for determining disease progress curves and the phenology of cotton plant growth and development. Effects of Fusarium wilt on plant height and boll set were determined in three successive years. Increases in both of these plant characteristics decreased or stopped before foliar symptoms were apparent. Seed cotton yields of plant cohorts that developed foliar wilt symptoms early in the season (before 2,000 F degree-days) were variable but not much different in these years. This contrasted with cohorts of plants that first showed foliar symptoms late in the season (after 2,400 F degree-days) and cohorts of plants that showed no foliar symptoms of wilt. Regression analyses for 1982-1984 indicated moderate to weak correlations (r = 0.16-0.74) of the time of appearance of the first foliar symptoms and seed cotton yields.
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Goodell PB, Ferris H. Influence of Environmental Factors on the Hatch and Survival of Meloidogyne incognita. J Nematol 1989; 21:328-334. [PMID: 19287616 PMCID: PMC2618941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
The influence of soil temperature and moisture on Meloidogyne incognita (Kofoid and White) Chitwood was examined in relation to hatching and survival of second-stage juveniles (J2). Nematodes were cultured on cotton (Gossypium hirsutum L. cv. Acala SJ2) under field conditions to provide populations similar to those found in the field in late autumn. Egg masses were placed in a temperature range (9-12 C and 21 C), and hatch was measured over a period equivalent to 20 degree days > 10 C (DD10). Hatch occurred below the reported 18 C activity threshold, was restricted below 12 C, and was inhibited below 10 C. Soil moisture influence on hatch was measured by placing egg masses in Hesperia sandy loam and subjecting them to suction pressures ranging from -1.1 bars to -4 .5 bars. Suction potentials of less than -2 bars reduced hatch and less than -3 bars inhibited hatch. J2 were placed in sandy loam soil with soil moisture near field capacity, and their motility was measured over a period of 500 DD10. In the absence of a host, more than 90% of J2 became nonmotile over this period.
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Goodell PB, Ferris H. Sample optimization for five plant-parasitic nematodes in an alfalfa field. J Nematol 1981; 13:304-313. [PMID: 19300768 PMCID: PMC2618089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
A data base representing nematode counts and soil weight from 1,936 individual soil cores taken from a 7-ha alfalfa field was used to investigate sample optimization for five plant-parasitic nematodes: Meloidogyne arenaria, Pratylenchus minyus, Merlinius brevidens, Helicotylenchus digonicus, and Paratrichodorus minor. Sample plans were evaluated by the accuracy and reliability of their estimation of the population and by the cost of collecting, processing, and counting the samples. Interactive FORTRAN programs were constructed to simulate four collecting patterns: random; division of the field into square sub-units (cells); and division of the field into rectangular sub-traits (strips) running in two directions. Depending on the pattern, sample numbers varied from 1 to 25 with each sample representing from 1 to 50 cores. Each pattern, sample, and core combination was replicated 50 times. Strip stratification north/south was the most optimal sampling pattern in this field because it isolated a streak of fine-textured soil. The mathematical optimmn was not found because of data range limitations. When practical economic time constraints (5 hr to collect, process, and count nematode samples) are placed on the optimization process, all species estimates deviate no more than 25 % from the true mean. If accuracy constraints are placed on the process (no more than 15% deviation from true field mean), all species except Merlinius required less than 5 hr to complete the sample process.
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