51
|
Tekin M, Mutlu C, Paparella MM, Schachern PA, Jaisinghani VJ, Le CT. Tympanic membrane and middle ear pathologic correlates in mucoid otitis media. Otolaryngol Head Neck Surg 2000; 123:258-62. [PMID: 10964301 DOI: 10.1067/mhn.2000.106708] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The goal of this study was to correlate tympanic membrane (TM) and middle ear (ME) pathologies in mucoid otitis media (MOM). METHODS AND MATERIAL Forty ears with MOM and 56 control ears were retrospectively evaluated for TM and ME pathologies. Comparisons of TM thicknesses in MOM versus control ears were correlated with the Student t test; chi(2) analysis was used to correlate pathologic findings of the TM and ME. RESULTS Thicknesses in all quadrants except the umbo were increased in MOM because of infiltration of inflammatory cells and fibrosis. The most common ME pathologies were granulation tissue and fibrosis. Significant correlations included (1) TM retraction and ME granulation tissue and fibrosis and (2) pars flaccida, posterosuperior, and anteroinferior thickness and ME granulation tissue and fibrosis. CONCLUSION TM changes are likely to occur in patients with otitis media with effusion (MOM), and their presence is a strong indication of underlying ME pathology.
Collapse
|
52
|
Lockhart NJ, Daly KA, Lindgren BR, Meland M, Le CT, Giebink GS. Low cord blood type 14 pneumococcal IgG1 but not IgG2 antibody predicts early infant otitis media. J Infect Dis 2000; 181:1979-82. [PMID: 10837178 DOI: 10.1086/315501] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/1999] [Revised: 02/14/2000] [Indexed: 11/03/2022] Open
Abstract
Type-specific IgG1 and IgG2 antibodies to Streptococcus pneumoniae capsular polysaccharides 14 and 19F were measured in cord blood samples from 425 neonates, to determine which antibody subclass was most strongly associated with otitis media (OM) during the first 6 months of life (early OM). Early OM was significantly associated with type 14 IgG1 antibody in the lowest antibody quartile (P=.055) but not with type 19F IgG1 antibody or with either IgG2 antibody. IgG1 and IgG2 antibodies were significantly intercorrelated for type 14 (r=.52, P<.001) and type 19F (r=.38, P<.001). Multivariate analysis revealed that having type 14 IgG1 antibody in the lowest quartile, child care attendance, and sibling and maternal OM history were independent risk factors for early OM. Although type-specific pneumococcal IgG2 antibody concentrations were significantly higher than IgG1 concentrations, IgG2 antibodies apparently are not protective against OM during early infancy.
Collapse
|
53
|
von Tress M, Le CT. Applied Categorical Analysis. Technometrics 2000. [DOI: 10.2307/1271468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
54
|
Kawano H, Paparella MM, Ho SB, Schachern PA, Morizono N, Le CT, Lin J. Identification of MUC5B mucin gene in human middle ear with chronic otitis media. Laryngoscope 2000; 110:668-73. [PMID: 10764016 DOI: 10.1097/00005537-200004000-00024] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To identify the mucin gene and its expressing cells in the middle ear mucosa with chronic otitis media (COM), and to study the correlation between infiltration of inflammatory cells in the submucosa and expression of the mucin gene in the mucosal epithelium with COM. STUDY DESIGN Middle ear mucosal specimens removed from the inferior promontory area of 19 patients undergoing middle ear surgery for COM were studied. METHODS Sections were stained with H&E, Alcian blue-periodic acid Schiff (AB-PAS), polyclonal MUC5B antibody, and specific MUC5B riboprobe for histological, histochemical, immunohistochemical, and mucin mRNA analyses. RESULTS H&E staining revealed pseudostratified epithelia in 18 of the middle ear specimens with COM and cuboidal secretory epithelia in one. AB-PAS staining of epithelia revealed abundant secretory cells and their products (glycoconjugates). In situ hybridization and immunohistochemistry studies demonstrated that the secretory cells of the middle ear mucosa with COM expressed MUC5B mucin mRNA and its product MUC5B mucin. CONCLUSIONS The MUC5B mucin gene and its product were identified in the middle ear secretory cells of patients with COM. Its expression was extensive in pseudostratified mucosal epithelia and related to infiltration of inflammatory cells in the submucosa of the middle ear cleft with COM, suggestive that inflammatory cell products are involved in the production of MUC5B.
Collapse
|
55
|
Yildirim N, Sone M, Mutlu C, Schachern PA, Paparella MM, Le CT. Histopathologic features of the temporal bone in patients with cystic fibrosis. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 2000; 126:75-8. [PMID: 10628715 DOI: 10.1001/archotol.126.1.75] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES To investigate the lower than expected incidence of otitis media in patients with cystic fibrosis (CF) through histopathologic evaluation of temporal bones and to document pathologic findings in the inner ears of patients with CF who received long-term administration of antibacterial and diuretic agents. DESIGN Clinical records of patients who died of CF were reviewed. Their temporal bones were sectioned, stained with hematoxylin-eosin, and examined histologically. Additional sections were stained with Alcian blue and periodic acid-Schiff for comparison of goblet cell densities from middle ears and auditory tubes of patients with CF with those of control temporal bones. Results were analyzed using the t test. SUBJECTS Twenty-one temporal bones from 11 patients with CF and 13 bones from 8 age-matched patients without CF were selected. RESULTS All temporal bones with CF had well-pneumatized mastoids. Temporal bones from 2 patients (3 ears) revealed histological findings of chronic otitis media with effusion. There was a statistically significant reduction in the density of goblet cells in the medial (P = .002) and lateral (P = .05) walls in patients with CF who had no otitis media histologically compared with control temporal bones. Two patients with CF who had otitis media had increased densities of goblet cells. Inner ear damage, due to ototoxic drugs, was seen in most of the temporal bones from patients with CF. CONCLUSION Low densities of goblet cells in temporal bones with CF may contribute reduced amounts of viscous mucus, which can lead to a low incidence of otitis media.
Collapse
|
56
|
|
57
|
Clohisy DR, Le CT, Cheng EY, Dykes DC, Thompson RC. Evaluation of the feasibility of and results of measuring health-status changes in patients undergoing surgical treatment for skeletal metastases. J Orthop Res 2000; 18:1-9. [PMID: 10716272 DOI: 10.1002/jor.1100180102] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The goal of treating patients with skeletal metastases is to decrease pain and improve or maintain physical function. Assessment of the effectiveness of treatment should therefore include evaluation of patient-rated measures of quality of life. The primary objective of the study was to determine the feasibility of studying the effect of surgical treatment of skeletal metastases on quality of life. The secondary objective was to provide data that begin to characterize this effect. The characteristics of patients with skeletal metastases are heterogeneous, patient enrollment in the study may be low, high attrition occurs secondary to death, and well accepted health-status measures (such as the Short Form-36) may be ineffective at detecting changes in health status; therefore, it is difficult to study these patients. High attrition and adjuvant treatment with radiation or chemotherapy made it impractical to draw firm conclusions about the effect of surgical treatment, but a trend toward improvement in selected health-status measures for both physical and mental health was noted. Analysis of patient-rated health-status scores as predictors of survival indicates that improvement in these scores 6 weeks after surgery is associated with an increase in the length of survival following surgery.
Collapse
|
58
|
Jaisinghani VJ, Paparella MM, Schachern PA, Schneider DS, Le CT. Residual mesenchyme persisting into adulthood. Am J Otolaryngol 1999; 20:363-70. [PMID: 10609480 DOI: 10.1016/s0196-0709(99)90075-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE (1) To detect the presence of residual mesenchyme in temporal bones of adults and children above 5 years of age; (2) to evaluate its regression with increasing age, and; (3) to detect pathologic conditions associated with the presence of unresolved mesenchyme. MATERIALS AND METHODS We examined 1,404 human temporal bones of donors from 5 to 94 years of age for histopathologic evidence of mesenchyme. The presence of stellate (star-shaped) cells with interdigitating processes and large nuclei embedded in a structureless ground substance was labeled as "pure mesenchyme." Temporal bones showing these features and focal areas of fibrosis, fibroblasts, and capillaries were classified as showing "transitional mesenchyme." Selected sections were stained with Gomori's trichrome. Pathological features indicating otitis media and congenital anomalies of the ear were also documented. Case histories were reviewed, and any otologic complaints were noted. Statistical analysis was performed with the Chi-square test, analysis of variance, regression analysis, and confidence interval. RESULTS Mesenchyme was found in 2.07% of temporal bones of patients from 5 to 81 years of age. Of these, 92.1% had transitional mesenchyme, whereas 7.9% had pure mesenchyme. Seventy-six percent of the bones showed mesenchyme in the mastoid air cells. In all 3 bones with pure mesenchyme, it was present in the round window niche. Otitis media was associated with residual mesenchyme in 84.2% of the temporal bones. No pattern of regression of mesenchyme with increasing age was observed in temporal bones from patients over the age of 5 years. CONCLUSIONS Residual mesenchyme can be present in patients older than 5 years of age and can persist into adulthood, especially in the mastoid air cells. Persistence of mesenchyme is closely associated with evidence of otitis media.
Collapse
|
59
|
Tekin M, Mutlu C, Paprella MM, Schachern PA, Le CT. Tympanic membrane thickness in mucoid otitis media. Otolaryngol Head Neck Surg 1999. [DOI: 10.1016/s0194-5998(99)80549-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
60
|
Ng MC, Harper RP, Le CT, Wong BS. Effects of estrogen on the condylar cartilage of the rat mandible in organ culture. J Oral Maxillofac Surg 1999; 57:818-23. [PMID: 10416629 DOI: 10.1016/s0278-2391(99)90823-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE The effects of estrogen on bone have been well documented. However, very little is known about the regulatory role of estrogen on cartilage and, in particular, the secondary cartilage of the mandibular condyle. The aims of this study were to determine whether estrogen receptors are present in the condylar cartilage of the rat mandible and to assess the effect of varying 17beta-estradiol (E2) concentrations on the proteoglycan content of this tissue. MATERIALS AND METHODS Mandibular condyles of 16 female Sprague-Dawley rats were resected. Eighteen of these condyles were divided into three groups and the condylar cartilage was removed and placed in organ culture for 4 days with media containing different concentrations of estrogen: 10(-11) mol/L, 10(-8) mol/L, and 10(-6) mol/L. The cartilage then was analyzed for proteoglycan content along with six specimens not passed through the organ culture. Six intact mandibular condyles also were resected and placed in organ culture with the same varying E2 concentrations, and the condylar cartilage was analyzed for estrogen receptors along with two condyles not passed through the culture system. RESULTS Estrogen receptors were evenly distributed within the chondroblastic and hypertrophic zones in the control group and the group with 10(-11) mol/L E2. With E2 concentrations of 10(-8) mol/L and 10(-6) mol/L, there was a qualitative decrease in hypertrophic chondroblasts, thickness of the condylar cartilage, and a significant decrease in proteoglycan content. CONCLUSIONS This study shows the presence of estrogen receptors in the secondary cartilage of the rat mandibular condyle. Estrogen has the potential to cause a decrease in extracellular matrix and thickness of this cartilage.
Collapse
|
61
|
Daly KA, Brown JE, Lindgren BR, Meland MH, Le CT, Giebink GS. Epidemiology of otitis media onset by six months of age. Pediatrics 1999; 103:1158-66. [PMID: 10353923 DOI: 10.1542/peds.103.6.1158] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Although early otitis media (OM) onset predicts later recurrent and chronic OM, little research has been directed at illuminating the role of prenatal exposures in early OM. This prospective study examined prenatal, innate, and early environmental exposures associated with acute otitis media (AOM) onset and recurrent OM (ROM) by age 6 months. DESIGN AND METHODS Prospective study of 596 infants from a health maintenance organization followed from birth to 6 months. Mothers completed monthly forms on prenatal exposures (diet, medications, and illnesses) and infant risk factors (eg, smoke exposure and child care) during pregnancy and until infants were 6 months old. Urine samples were collected when infants were 2 months of age and analyzed for cotinine and creatinine. Physicians and nurse practitioners examined infants at each clinic visit and completed standard ear examination forms. RESULTS Thirty-nine percent had an episode of AOM and 20% had ROM by age 6 months. Using Cox's regression models to control for confounding, respiratory tract infection (relative risk [RR] 7.5), day care (RR 1. 7), >1 sibling (RR 1.4), maternal, paternal, and sibling OM history (RR 1.6, 1.5, and 1.7, respectively) were significantly related to early OM onset. ROM was related to respiratory tract infection (RR 9. 5), day care (RR 1.9), conjunctivitis (RR 2.0), maternal OM history (RR 1.9), and birth in the fall (RR 2.6). Among prenatal exposures, only high prenatal dietary vitamin C intake was significantly inversely related to early AOM with univariate but not multivariate analysis. CONCLUSION Prenatal factors were not linked to early AOM onset with multivariate analysis, but environmental and innate factors play an important role in early AOM onset. Strategies to reduce exposure to environmental variables could reduce rates of early AOM, which could potentially result in declining rates of ROM and chronic OME.
Collapse
|
62
|
Jaisinghani VJ, Paparella MM, Schachern PA, Le CT. Tympanic membrane/middle ear pathologic correlates in chronic otitis media. Laryngoscope 1999; 109:712-6. [PMID: 10334219 DOI: 10.1097/00005537-199905000-00007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To correlate pathologic findings of the tympanic membrane with pathologic changes in the middle ear cleft in chronic otitis media. STUDY DESIGN Retrospective. MATERIAL AND METHODS One hundred-fifty temporal bones from 97 subjects with chronic otitis media (defined as middle ear pathologic changes including granulation tissue, fluid, cholesteatoma, cholesterol granuloma, tympanosclerosis, and ossicular changes) were selected to correlate the presence of these middle ear pathologies with histopathologic changes of the tympanic membrane. The tympanic membrane pathologies included perforation, myringosclerosis, retraction, hemorrhage, fluid-filled cystic spaces, or dilated vessels. Temporal bones were also assessed for atelectasis. Fifty-six normal temporal bones were taken as controls for measurements. RESULTS Significant correlations between tympanic membrane and middle ear pathology included myringosclerosis and granulation tissue, myringosclerosis and ossicular pathology, retraction and cholesterol granuloma, retraction and cholesteatoma, retraction and ossicular pathology, perforation and ossicular pathology, and hemorrhage and granulation tissue. Additive effects of some pathologies were also observed. Almost half the bones with middle ear pathology had no associated tympanic membrane pathology, whereas multiple pathologic changes in the tympanic membrane generally showed underlying multiple pathologic changes in the middle ear. CONCLUSION When tympanic membrane pathology is detected otoscopically, its presence, alone or in combination, can be a strong indicator of underlying middle ear pathology. However, a normal-appearing tympanic membrane does not exclude the possibility of middle ear pathology. These findings suggest the need for other diagnostic tools such as multifrequency tympanometry and otoacoustic emissions to complement otoscopy for diagnosis of middle ear pathology, especially in a tympanic membrane that appears "normal."
Collapse
|
63
|
Sato K, Liebeler CL, Quartey MK, Le CT, Giebink GS. Middle ear fluid cytokine and inflammatory cell kinetics in the chinchilla otitis media model. Infect Immun 1999; 67:1943-6. [PMID: 10085040 PMCID: PMC96550 DOI: 10.1128/iai.67.4.1943-1946.1999] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is the most frequent microbe causing middle ear infection. The pathophysiology of pneumococcal otitis media has been characterized by measurement of local inflammatory mediators such as inflammatory cells, lysozyme, oxidative metabolic products, and inflammatory cytokines. The role of cytokines in bacterial infection has been elucidated with animal models, and interleukin (IL)-1beta, IL-6, and IL-8 and tumor necrosis factor alpha (TNF-alpha) are recognized as being important local mediators in acute inflammation. We characterized middle ear inflammatory responses in the chinchilla otitis media model after injecting a very small number of viable pneumococci into the middle ear, similar to the natural course of infection. Middle ear fluid (MEF) concentrations of IL-1beta, IL-6, IL-8, and TNF-alpha were measured by using anti-human cytokine enzyme-linked immunosorbent assay reagents. IL-1beta showed the earliest peak, at 6 h after inoculation, whereas IL-6, IL-8, and TNF-alpha concentrations were increasing 72 h after pneumococcal inoculation. IL-6, IL-8, and TNF-alpha but not IL-1beta concentrations correlated significantly with total inflammatory cell numbers in MEF, and all four cytokines correlated significantly with MEF neutrophil concentration. Several intercytokine correlations were significant. Cytokines, therefore, participate in the early middle ear inflammatory response to S. pneumoniae.
Collapse
|
64
|
Sone M, Paparella MM, Schachern PA, Morizono N, Le CT, Lin J. Expression of glycoconjugates in human eustachian tubes with otitis media. Laryngoscope 1998; 108:1474-9. [PMID: 9778286 DOI: 10.1097/00005537-199810000-00010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To characterize glycoconjugate expression in normal human eustachian tubes and study the alterations in glycoconjugate expression found in eustachian tubes with otitis media. STUDY DESIGN Using lectin histochemistry, alterations in glycoconjugates were studied in three normal temporal bones, in four temporal bones with mucoid otitis media (MOM), and in five with serous otitis media (SOM). METHODS Sections of previously processed temporal bones were decelloidinized, and then incubated with seven biotinylated lectins--WGA, SNA, MAA, BPA, PNA, UEA-1, and LcH--that reflect seven carbohydrate residues of glycoconjugates, respectively: GlcNAc/NeuNAc, NeuNAc alpha(2-6)GalNAc, NeuNAc alpha(2-3)GalNAc, Gal beta(1-3) GalNAc, L-fucose, and alpha-mannose residues. Control sections were incubated with inhibitory carbohydrates or without biotinylated lectins. RESULTS In the normal temporal bones, five carbohydrate residues in goblet cells and cilia of the eustachian tube demonstrated moderate to strong activity--NeuNAc alpha(2-6)GalNAc, NeuNAc alpha(2-3)GalNAc, GalNAc, Gal beta(1-3)GalNAc, and L-fucose. Two residues demonstrated weak activity--GlcNAc/NeuNAc and alpha-mannose. Temporal bones with MOM revealed increases in sialic acid and alpha-mannose, and a decrease in L-fucose. Residues of carbohydrates in the cilia of bones with SOM were notably decreased, especially for GalNAc, Gal beta(1-3)GalNAc, and NeuNAc alpha(2-6)GalNAc. CONCLUSIONS Glycoconjugates in the normal human eustachian tube are rich in GalNAc, Gal beta(1-3)GalNAc, L-fucose, and NeuNAc alpha(2-3/2-6) GalNAc, but low in alpha-mannose and sialic acid. Eustachian tubes from cases with SOM or MOM demonstrated alterations in glycoconjugate expression in cilia and goblet cells, which may reflect disorder of the carbohydrate metabolism during otitis media, especially in SOM.
Collapse
|
65
|
Rennels MB, Parashar UD, Holman RC, Le CT, Chang HG, Glass RI. Lack of an apparent association between intussusception and wild or vaccine rotavirus infection. Pediatr Infect Dis J 1998; 17:924-5. [PMID: 9802640 DOI: 10.1097/00006454-199810000-00018] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
66
|
Wassell JT, Le CT. Applied Survival Analysis. J Am Stat Assoc 1998. [DOI: 10.2307/2669878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
67
|
Kayhan FT, Mutlu C, Schachern PA, Le CT, Paparella MM. Significance of epidermoid formations in the middle ear in fetuses and children. ARCHIVES OF OTOLARYNGOLOGY--HEAD & NECK SURGERY 1997; 123:1293-7. [PMID: 9413356 DOI: 10.1001/archotol.1997.01900120043006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine the incidence, size, and location of epidermoid formations (EFs), which have been suggested to be precursors of congenital cholesteatomas, in temporal bones from fetuses and children. DESIGN We examined temporal bones from 226 fetuses and children up to the age of 10 years for the incidence, size, and location of EFs. RESULTS Twenty-five EFs were identified in middle ears of 3 fetuses, 7 neonates, 9 infants, and 2 children aged 2 and 3 years. There was a male-female preponderance of 5:4. Generally, we saw EFs between the anterosuperior edge of the eardrum and the anterior limb of the tympanic ring, but 4 were below the level of the handle of the malleus. Their widths ranged from 25 to 300 microns. Keratinization was not observed in any EF. Contrary to previous reports, we found EFs not only in ears of fetuses, but also in ears of infants and children. CONCLUSION Although EFs may persist in some ears, possibly developing into congenital cholesteatomas, our findings do not provide direct support for this concept.
Collapse
|
68
|
Le CT. Evaluation of confounding effects in ROC studies. Biometrics 1997; 53:998-1007. [PMID: 9290227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In many clinical studies, it is clear that external forces can affect the performance of diagnostic tests, as these factors influence the distributions of separator variables. A new estimator for the receiver operating characteristic (ROC) function is proposed; this estimator converges to the ROC function uniformly on the interval [0,1]. Using this new estimator, the author proposes to use Cox's proportional hazards regression model for the evaluation of confounding effects in ROC studies. The method can be used even when concomitant information is only available for the cases, for example, disease severity. A textbook example on prostate cancer is described for illustration.
Collapse
|
69
|
|
70
|
Clohisy DR, Le CT, Umen AJ. Measuring health status in patients with skeletal metastases treated by surgery. Am J Clin Oncol 1997; 20:424-8. [PMID: 9256904 DOI: 10.1097/00000421-199708000-00022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Since the introduction of the Functional Living Index-Cancer (FLIC) > 10 years ago, a variety of general as well as disease-specific quality of life (QOL) instruments have been developed and used as a means of assessing the success of clinical interventions. Clinicians faced with selecting an appropriate QOL measurement tool will need guidance in both the selection of the instrument and its evaluation for applicability to the patient group under study. In our examination of this issue, we analyzed the results of administering the FLIC and the more general SF-36 questionnaire to a group of 17 patients who had undergone orthopaedic surgery to correct problems associated with bone metastatic cancer. Because the SF-36 has been widely adopted as a general Health Status evaluation tool and because of its extensive validation it may be considered a gold standard providing a means of assessing the validity of disease-specific instruments such as the FLIC. Using multivariate regression, we built a model in which five of the eight health status dimensions of the SF-36 account for 77% of the variation in the FLIC scores for this group of patients (R2 = 0.77). The implication of this result is that most of the information (i.e., 77%) provided by the FLIC could be equivalently obtained using the more general, more widely validated SF-36. Despite the small sample size, half of the regression coefficients in this model achieved a high level of statistical significance (p < 0.001). In addition, when applied to new patients, the model showed good predictive capability with relative error 2-20%. If these results can be replicated for other patient disease groups and in larger study populations, it may be possible to use the SF-36 as the primary QOL evaluation tool for cancer patients. The burden of this disease could then be more easily compared with that of other disease groups and the resulting standardization of QOL analysis would be simpler and more cost effective.
Collapse
|
71
|
Salazar JC, Daly KA, Giebink GS, Lindgren BR, Liebeler CL, Meland M, Le CT. Low cord blood pneumococcal immunoglobulin G (IgG) antibodies predict early onset acute otitis media in infancy. Am J Epidemiol 1997; 145:1048-56. [PMID: 9169914 DOI: 10.1093/oxfordjournals.aje.a009061] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Low maternally derived serum immunoglobulin G (IgG) antibodies to Streptococcus pneumoniae capsular polysaccharides (PS) combined with the inability of infants to produce anti-PS antibody may explain onset of otitis media in the first 6 months of life. To explore this relation, cord blood samples were assayed for anti-PS IgG antibodies from 414 of 592 infants enrolled in a study of early onset otitis media between 1991 and 1994. Infants' ears were examined at health supervision and illness visits for the first 6 months of life in a large Minneapolis-St. Paul, Minnesota, health maintenance organization. Antibodies to seven common pneumococcal serotypes (3, 4, 6B, 14, 18C, 19F, and 23F) were measured by enzyme-linked immunoabsorbent assay (ELISA). Cox's regression analysis revealed that among infants with a sibling otitis media history, those with low concentrations of type 14 or 19F anti-PS cord blood antibody had earlier otitis media onset than those with higher cord blood antibody concentrations (relative risks (RR) (95% confidence intervals (CI)) = 1.77 (1.05-2.99) and 1.89 (1.11-3.23), respectively). Day care attendance also increased risk (RR = 1.56, 95% CI 0.96-2.52). Breastfeeding, parental smoking, and low anti-PS antibody to pneumococcal serotypes 3, 4, 6B, 18C, and 23F did not significantly affect the risk of early otitis media.
Collapse
|
72
|
Gerberich SG, Gibson RW, Fife D, Mandel JS, Aeppli D, Le CT, Maxwell R, Rolnick SJ, Renier C, Burlew M, Matross R. Effects of brain injury on college academic performance. Neuroepidemiology 1997; 16:1-14. [PMID: 8994935 DOI: 10.1159/000109665] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Brain injury, a leading cause of mortality, morbidity and disability in the United States, has serious consequences and substantial costs. Although previous studies have assessed a variety of outcomes subsequent to brain injury, documentation of performance prior to brain injury using a case-control approach has not been included; preinjury performance differences may confound the estimate of the effects of brain injury on performance. The primary objective of this study was to compare academic performance before and after brain injury in a population of university undergraduate students to determine the extent to which the academic career of the brain-injured person was altered from what would have been expected in the absence of such an injury. Cases included all undergraduate students in a major university, between the ages of 17 and 27, who incurred a brain injury requiring hospitalization between 1980 and 1984 (n = 99). Two comparison groups were used to determine whether changes in academic performance were specifically related to brain injuries or injuries in general: (1) injured controls, i.e. 121 students between the ages of 17 and 27 years, hospitalized for injuries other than to the central nervous system, and (2) uninjured academic controls, i.e. 198 students with out injuries requiring hospitalization during the study period, matched 2:1 to the brain-injured students by age, gender, and completed course credits categorized as < 90, > or = 90. Although there were no differences when the total groups, including both males and females, were compared, there was a significant pre- to postinjury decrease in the grade point average for female cases when compared to their uninjured academic controls (p < 0.02). This difference was related to the effects of brain injury, and not to the effects of injury in general. No such difference was observed for the males. There were also no differences when the total groups, including males and females, were compared relevant to return to school. However, a significantly higher proportion of the female cases, compared with their uninjured academic controls, did not return to school after their injury; similar findings were identified for the injured controls as well. Thus, these differences were not specific to brain injury but rather to injury in general. In spite of this observation, the difference between female cases who returned and those who did not return was associated with neurological deficits, especially upper left limb motor deficits, as the time of hospital discharge. The findings from this effort are suggestive of gender differences in the consequences of brain injury and serve as a basis for further studies to evaluate the magnitude of this problem.
Collapse
|
73
|
Abstract
The role of mesenchyme in the temporal bone is still poorly understood. A microscopic study of residual mesenchyme was undertaken in temporal bones of children from birth to 5 years of age. Residual mesenchyme was found to be located in the mastoid antrum and epitympanum more often than in the mesotympanum. The amount of mesenchymal tissue remaining in the temporal bones decreased with increasing age. Persistence of mesenchyme in the temporal bone was related to congenital morphologic ear anomalies and syndromes. There was also an association evident with pulmonary disease, but not with congenital heart defects. Persistent mesenchyme was also found to be significantly associated with chronic middle ear inflammation, and in cases of unilateral otitis media the ear with otitis media had more residual mesenchyme than the non-otitis media ear.
Collapse
|
74
|
|
75
|
Sato K, Quartey MK, Liebeler CL, Le CT, Giebink GS. Roles of autolysin and pneumolysin in middle ear inflammation caused by a type 3 Streptococcus pneumoniae strain in the chinchilla otitis media model. Infect Immun 1996; 64:1140-5. [PMID: 8606070 PMCID: PMC173895 DOI: 10.1128/iai.64.4.1140-1145.1996] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Streptococcus pneumoniae cell wall and pneumolysin are important contributors to pneumococcal pathogenicity in some animal models. To further explore these factors in middle ear inflammation caused by pneumococci, penicillin-induced inflammatory acceleration was studied by using three closely related pneumococcal strains: a wild-type 3 strain (WT3), its pneumolysin-negative derivative (P-1), and into autolysin-negative derivative (A-1). Both middle ears of chinchillas were inoculated with one of the three pneumococcal strains. During the first 12 h, all three strains grew in vivo at the same rate, and all three strains induced similar inflammatory cell responses in middle ear fluid (MEF). Procaine penicillin G was given as 12 h to one-half of the animals in each group, and all treated chinchillas had sterile MEF at 24 h. Penicillin significantly accelerated MEF inflammatory cell influx into WT3-and P-1-infected ears at 18 and 24 h in comparison with the rate for penicillin-treated A-1-infected ears. Inflammatory cell influx was slightly, but not significantly, greater after treatment of WT3 infection than after treatment of P-1 infection. Interleukin (IL)-1beta and IL-6, but not IL-8, concentrations in MEF at 24 h reflected the penicillin effect on MEF inflammatory cells; however, differences between treatment groups were not significant. Results suggest that pneumococcal otitis media pathogenesis is triggered principally by the inflammatory effects of intact and lytic cell wall products in the middle ear, with at most a modes additional pneumolysin effect. Investigation strategies that limit the release of these products or neutralize them warrant further investigation.
Collapse
|