Outcomes in Severe Upper GI Hemorrhage from Dieulafoy's Lesion with Monitoring of Arterial Blood Flow.

BACKGROUND: Dieulafoy's lesion (DL) is a rare but increasingly recognized cause of severe upper GI hemorrhage (SUGIH). There is little consensus regarding the endoscopic approach to management of bleeding from DL. AIMS: Our purposes were to compare 30-day outcomes of patients with SUGIH from DL with Doppler endoscopic probe (DEP) monitoring of blood flow and guided treatment versus standard visually guided hemostasis (VG). METHODS: Eighty-two consecutive DL patients with SUGIH were identified in a large CURE Hemostasis database from previous prospective cohort studies and two recent RCTs at two university-based medical centers. 30-day outcomes including rebleeding, surgery, angiography, death, and severe medical complications were compared between the two treatment groups. RESULTS: 40.2% of DL bleeds occurred in inpatients. 43.9% of patients had cardiovascular disease, and 48.7% were taking medications associated with bleeding. For the entire cohort, 41.3% (26/63) of patients treated with VG had a composite 30-day outcome as compared to 10.5% (2/19) of patients treated with DEP (p = 0.017). Rebleeding occurred within 30 days in 33.3% and 10.5% of those treated with VG and DEP, respectively (p = 0.051). After propensity score matching, the adjusted 30-day composite outcome occurred in 39.0% in the VG group compared to 2.6% in the DEP group (p < 0.001). Adjusted 30-day rebleeding occurred in 25.3% in the VG group versus 2.6% in the DEP group (p < 0.001). DISCUSSION: DL patients with SUGIH were frequently inpatients and had severe cardiovascular comorbidities and recurrent bleeding. Lesion arterial blood flow monitoring and obliteration are an effective way to treat bleeding from DL which reduces negative 30-day clinical outcomes.

The prevalence, and predictive value, of abnormal anal cytology to diagnose anal dysplasia in a population of HIV-positive men who have sex with men.

Due to the increasing incidence of anal cancer in HIV-positive men who have sex with men, and the potential to detect and treat high-grade anal dysplasia--the putative anal cancer precursor--we have introduced an anal cytology screening service. Patients with abnormal anal cytology have follow-up high-resolution anoscopy (HRA) with biopsy of lesions clinically suspicious for high-grade dysplasia. In total, 244 men were screened and 235 (96%) of the samples were adequate for cytological interpretation using the Bethesda 2001 system. One hundred and sixty-four (67%) men had abnormal anal cytology, and 93 of them had follow-up HRA and anal biopsy. The positive predictive value for any anal cytological abnormality to predict any degree of anal dysplasia was 95.7+/-2.1%, and for any anal cytological abnormality to predict high-grade anal dysplasia was 55.9+/-5.1%. Abnormal anal cytology was highly predicative of anal dysplasia on biopsy.

Antiarrhythmic prophylaxis vs warfarin anticoagulation to prevent thromboembolic events among patients with atrial fibrillation. A decision analysis.

BACKGROUND: Patients with atrial fibrillation compared with those with sinus rhythm are at increased risk for thromboembolism, often mandating therapy directed at thromboembolism prevention. However, the safest, most efficacious strategy to prevent thromboembolism associated with atrial fibrillation is unknown. We developed a decision analysis to compare the risks and benefits of two common clinical strategies to prevent thromboembolism in the patient with atrial fibrillation: (1) sinus rhythm maintenance with quinidine sulfate or with amiodarone hydrochloride after cardioversion and (2) long-term anticoagulation with warfarin sodium. METHODS: A search was conducted of the English-language MEDLINE databases of the National Library of Medicine dated 1966 through December 1992. The search was conducted by intersecting "quinidine," "warfarin," or "amiodarone" with "atrial fibrillation." Six of 249 articles concerning quinidine and five of 20 articles concerning warfarin were judged by multiple reviewers to meet predetermined inclusion and exclusion criteria. To our knowledge, no randomized, placebo-controlled trials of amiodarone therapy for atrial fibrillation have been published. Five of 112 identified articles concerning amiodarone involved nonrandomized trials that met the remaining selection criteria and were included in this analysis. RESULTS: Thromboembolic events and fatal nonthromboembolic adverse events during the course of therapy (defined as fatal proarrhythmia, fatal hemorrhage, and fatal noncardiac toxic effects) were considered to have equivalent weight. The total risk during therapy, defined as thromboembolic and fatal nonthromboembolic adverse events during the course of therapy, was evaluated over a range of baseline thromboembolism risks, from 1% to 20% per patient-year. Quinidine therapy compared with no therapy was associated with increased total risk, unless baseline thromboembolism risk exceeded 11% per patient-year. Total risk during warfarin therapy was less than total risk during quinidine therapy for the entire range of baseline thromboembolism risks, from 1% to 20% per patient-year. Total risk during warfarin or amiodarone therapy was similar and less than that with no therapy for the entire range of baseline risks. CONCLUSIONS: Based on data from randomized, controlled trials of quinidine and warfarin, warfarin therapy appears to be the safest strategy for thromboembolism prevention in the patient with atrial fibrillation. The role of low-dose amiodarone therapy appears promising and warrants further study in randomized, controlled trials.

Production of interleukin-1 by microglia in response to substance P: role for a non-classical NK-1 receptor.

Substance P (SP) is a central and peripheral neurotransmitter which has been found in multiple sclerosis plaques. SP stimulates peripheral immune cells and may play a role in some chronic inflammatory diseases. Human peripheral monocyte/macrophages have been shown to produce the inflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) in response to SP. Therefore, in this study we examined rat brain microglia for the presence of SP receptors and production of IL-1 and TNF alpha in response to SP. Microglia had 4900 +/- 950 (mean +/- SE) receptors per cell fitting a two-site model. Four percent of these were high-affinity receptors with a Kd of 8.2 x 10(-8) M +/- 3.6 x 10(-8) M (mean +/- SE), and 96% of them were low-affinity receptors with a Kd of 2.1 x 10(-6) M +/- 5.2 x 10(-7) M (mean +/- SE). Competitive studies with CP 96,345 and other SP analogs demonstrate these to be non-classical NK-1 receptors. SP alone did not stimulate IL-1 or TNF alpha production. However, SP in synergy with lipopolysaccharide (LPS) quadrupled IL-1 production compared to LPS alone, but did not affect TNF alpha production. These results have implications for certain inflammatory conditions in the central nervous system.

Factors affecting growth after pediatric liver transplantation.

BACKGROUND: Poor linear growth after pediatric orthotopic liver transplantation (OLT) is a well-described phenomenon. We have undertaken a bivariate and multivariate analysis of multiple factors that might effect postOLT growth in all children who underwent transplantation at a single center, with survival > 1 year and adequate follow-up. METHODS: Standardized height score (Z score) and height deficit (centimeters below the 50th percentile) were computed for each patient over time. The variables assessed were (i) age at OLT, (ii) gender, (iii) pretransplantation diagnosis, (iv) Z score and height deficit at OLT, (v) tacrolimus versus cyclosporine as primary immunosuppressive therapy, (vi) retransplantation, (vii) graft disease, (viii) chronic illness, (ix) posttransplant lymphoproliferative disease, (x) intractable rejection, and (xi) prednisone withdrawal. RESULTS: A total of 236 children met the inclusion criteria, with a mean follow-up of 3.8+/-1.9 years. For the population as a whole, the baseline Z score was -1.72 (fourth percentile) with a significant improvement to - 1.37 (ninth percentile) at 2 years, but with no additional gain at 5 years (Z score -1.4). The baseline height deficit was -6.4 cm, with no improvement at 2 years (-6.52 cm), and was significantly worse at 5 years (-7.87 cm). In the bivariate analysis, the most important variables affecting growth were age at OLT, Z score at OLT, and diagnosis. In general, children <2 years with biliary atresia and those with the most growth delay at OLT showed the best posttransplantation growth. In the multivariate analysis, 18 factors were considered, of which 9 were significant. These were (i) Z score at baseline, (ii) follow-up time, (iii) age at OLT, (iv) diagnosis of tumor, (v) diagnosis of fulminant hepatic failure, (vi) retransplantation, (vii) graft disease, (viii) posttransplant lymphoproliferative disease, and (ix) stoppage of prednisone. Multivariate models using these nine variables accounted for 84% of the variation in standardized height. CONCLUSION: In general, children after OLT show some potential for catch-up growth but do not achieve normal height compared with their age and sex-matched peers. A multivariate analysis was necessary to investigate the interdependent effects of the many variables that can affect growth after OLT. The most important detrimental affects were older age at time of OLT, Z scores greater than -2.0 at OLT, fulminant hepatic failure, tumor, and postOLT complications causing graft dysfunction.

Serum lipid abnormalities in pediatric liver transplant patients.

UNLABELLED: Little is known about serum lipid abnormalities in pediatric liver transplant recipients. We performed a longitudinal cohort review of 102 outpatient pediatric liver recipients surviving greater than 6 months and immunosuppressed with cyclosporine and prednisone (+/- azathioprine). The median age was 6 years, median months posttransplant 25, and male-to-female ratio 1:1.5. The average cholesterol (mean of individual means) was 177 +/- 45 mg/dl and average triglyceride level 158 +/- 71 mg/dl. The mean percent of cholesterol levels greater than 170 mg/dl and triglyceride levels greater than 140 mg/dl was 47% and 50%, respectively. Age, obesity, sex, and family history of risk factors had no significant effect on cholesterol or triglyceride levels. Bivariate regression analysis showed no meaningful association between cholesterol or triglyceride levels and cyclosporine levels, cyclosporine dose, prednisone dose, or diastolic blood pressure. Triglyceride and cholesterol neither increased nor decreased with time posttransplant. The rate of change of triglyceride or cholesterol could not be predicted by the rate of change of cyclosporine levels (or dose), or prednisone dose. We found no evidence that rises or falls in cholesterol or triglyceride levels coincided with rises or falls in either cyclosporine level or prednisone dose. Cholestasis was significantly associated with increased cholesterol and triglyceride levels (P = 0.05). A multivariate analysis was unable to predict cholesterol or triglyceride levels from three predictors: cyclosporine level, prednisone dose, and liver function. The mean dietary intake of fat and cholesterol was above RDA and exercise patterns were suboptimal in school-aged children. CONCLUSIONS: 50% of children had a mean cholesterol greater than 75th percentile (170 mg/dl); 20% were above the 95th percentile; 56% had a mean triglyceride level greater than 140 mg/dl. By these criteria the majority of pediatric liver transplant patients have lipid abnormalities that may predispose them to atherosclerosis in later life.

Perioperative blood transfusions and decreased long-term survival in esophageal cancer.

We evaluated retrospectively the effect of perioperative blood transfusions on survival in esophageal cancer. The records of all patients who underwent esophageal resection (n = 316) at UCLA Medical Center from 1970 to 1993 were reviewed. Statistical analysis included univariate (log-rank chi 2) and multivariate (Cox proportional hazards) analyses with other known risk factors. High-volume blood transfusions (> 8 units) but not low-volume blood transfusions (1 to 8 units) were associated with a significant decrease in long-term survival (median survival: no transfusion, 22 months; low-volume blood transfusion, 14.5 months, versus high-volume blood transfusions, 6.5 months; p < 0.01). Multivariate analysis revealed that the shorter survival with high-volume blood transfusions was a result of an increased number of postoperative complications. High-volume blood transfusions were not associated with increases in tumor recurrence or infectious complications. The association between shorter survival and high-volume blood transfusions in esophageal cancer may, therefore, be because of the circumstances necessitating transfusion rather than any immunosuppressive effects of the transfused blood. These findings suggest that the transfusion of blood does not by itself decrease the chance of cure after esophageal resection.

The influence of luteinizing hormone and insulin on sex steroids and sex hormone-binding globulin in the polycystic ovarian syndrome.

OBJECTIVE: To examine the relationship between hyperinsulinemia, sex hormone-binding globulin (SHBG), and body mass index (BMI) on LH-induced hyperandrogenemia in patients with polycystic ovarian syndrome (PCOS). DESIGN: Insulin responses during an oral glucose tolerance test (OGTT) were assessed in 25 consecutive women with PCOS and 20 control women matched for BMI. Insulin responses and sensitivity (SI) were also determined using a frequently sampled intravenous glucose tolerance test (IVGTT). SETTING: The clinical research center at a university medical center. MAIN OUTCOME MEASURES: Serum LH, SI, and basal, peak, and area under the curve (AUC-insulin responses) were determined and correlated with SHBG, androstenedione (A), T, and free T concentrations. RESULTS: Compared with controls, the AUC-insulin response during OGTT was greater in PCOS, with an average increase of 44%. During IVGTT, AUC-insulin response was also significantly higher in PCOS versus controls, with an average increase of 53%. In addition, SI was reduced in PCOS versus controls with an average decrease of 53%. The average differences in oral- and intravenous-glucose-induced hyperinsulinemia and in insulin sensitivity between PCOS and controls were relatively constant across the entire physiological range of BMI. In PCOS, baseline LH showed strong positive correlations with baseline A and T. However, there were no significant correlations between either basal, peak, or AUC-insulin response during OGTT and IVGTT with basal T or A concentrations or between insulin and androgen levels measured at 30-minute intervals throughout the OGTT. However, basal, peak, and AUC-insulin responses during OGTT were strongly correlated with fasting SHBG binding capacity. CONCLUSIONS: These data are consistent with the hypothesis that hyperinsulinemia in PCOS influences the biologically active component of T by lowering SHBG concentrations while having little apparent impact on LH-induced secretion of androgens in vivo.

A multiple logistic regression analysis of the risk and relative odds of temporomandibular disorders as a function of common occlusal features.

A multiple logistic regression analysis was used to compute the odds ratios for 11 common occlusal features for asymptomatic controls (n = 147) vs. five temporomandibular disorder groups: Disc Displacement with Reduction (n = 81), Disc Displacement without Reduction (n = 48), Osteoarthrosis with Disc Displacement History (n = 75), Primary Osteoarthrosis (n = 85), and Myalgia Only (n = 124). Features that did not contribute included: retruded contact position (RCP) to intercuspal position (ICP) occlusal slides < or = 2 mm, slide asymmetry, unilateral RCP contacts, deep overbite, minimal overjet, dental midline discrepancies, < or = 4 missing teeth, and maxillo-mandibular first molar relationship or cross-arch asymmetry. Groupings of a minimum of two to at most five occlusal variables contributed to the TMD patient groups. Significant increases in risk occurred selectively with anterior open bite (p < 0.01), unilateral maxillary lingual crossbite (p < 0.05 to p < 0.01), overjets > 6-7 mm (p < 0.05 to p < 0.01), > or > 5-6 missing posterior teeth (p < 0.05 to p < 0.01), and RCP-ICP slides > 2 mm (p < 0.05 to p < 0.01). While the contribution of occlusion to the disease groups was not zero, most of the variation in each disease population was not explained by occlusal parameters. Thus, occlusion cannot be considered the unique or dominant factor in defining TMD populations. Certain features such as anterior open bite in osteoarthrosis patients were considered to be a consequence of rather than etiological factors for the disorder.

Incomplete data in repeated measures analysis.

Complete (or balanced) repeated measures data arise when all subjects in a study are measured at the same set of time points. Data are often incomplete, because measurements are missed, or the design of the study results in subjects being measured at different sets of time points. This article reviews methods of analysis for incomplete repeated-measures data of this form, from an applied statistician's perspective. Limitations of approaches that (a) ignore between-subject variation, or (b) impute for missing values are discussed. Two methods are advocated that are relatively easy to implement using existing software, namely between-subject analysis of within-subject summary measures, and maximum likelihood based on a model for the data. Methods are applied and compared on four real-data examples with varied analytical objectives.

Effectiveness and safety of brimonidine as adjunctive therapy for patients with elevated intraocular pressure in a large, open-label community trial.

PURPOSE: To determine the effectiveness and safety of brimonidine when used in combination with one or more glaucoma medications in patients with glaucoma or ocular hypertension. METHODS: Post hoc analysis of a multicenter, 2-month, open-label, prospective, clinical trial in which 2,335 patients received brimonidine as monotherapy, replacement therapy, or combination therapy. Patients who received brimonidine as combination therapy (n = 554) were examined in the current analysis. Efficacy was determined by the reduction in intraocular pressure (IOP) from baseline before the addition of brimonidine. Safety and tolerability parameters included adverse events and quality-of-life measures (e.g., ocular comfort, energy level, breathing ability, night vision). RESULTS: Addition of brimonidine to preexisting regimens resulted in an overall mean additional reduction in IOP of 17.9% (4.26 mm Hg) at month 2 (P < 0.001). Significant additional IOP lowering was provided by brimonidine in combination with each preexisting regimen evaluated (P < or = 0.061). When brimonidine was added to monotherapy with a nonselective beta-blocker, the mean additional IOP reduction was 15.5% (3.61 mm Hg, P < 0.001). Addition of brimonidine to latanoprost monotherapy provided a 32.2% (5.89 mm Hg) mean additional IOP reduction (P < 0.001). Addition of brimonidine to combination regimens that included latanoprost provided additional mean decreases in LOP ranging from 15.5% (3.63 mm Hg, P < 0.002) to 20.1% (6.62 mm Hg, P < 0.001). All quality-of-life parameters remained high or improved during the study. Mild to moderate adverse events were reported in 5.23% of patients (29 of 552); 98.1% of physicians rated brimonidine adjunctive therapy as good or excellent. CONCLUSIONS: Brimonidine, when added to existing glaucoma regimens, safely and effectively lowered IOP in this community-based trial.

Comparing measures of reliability for indices of gingivitis and plaque.

The purpose of this methodological study was to compare methods used to assess reliability for gingival inflammation and plaque. Duplicate examinations were conducted by one examiner on 17 subjects (506 scoring sites), using the gingival index (GI), bleeding points index (BPI), and plaque index (PI). The percentage of agreement, the weighted and unweighted kappa coefficients, and Pearson correlation coefficients were calculated as statistics of reliability for mesial buccal site scores and whole mouth mean scores when appropriate. For mesial buccal sites the respective values of the GI, BPI, and PI for weighted kappas were: 0.47, 0.49, and 0.75; for the correlation coefficients: 0.47, 0.49, and 0.76; for unweighted kappas, 0.39, 0.49, and 0.39; and for percentage of agreement 66.2%, 76.1%, and 51.2%. For whole mouth means the correlation coefficients for the GI, BPI, and PI were 0.87, 0.59, and 0.87, respectively. In conclusion, the most useful statistics in assessing the intraexaminer reliability of a solo examiner in descending order were the weighted kappa coefficient, Pearson correlation coefficient, the unweighted kappa coefficient, and percentage of agreement.

Thermographic assessment of craniomandibular disorders: diagnostic interpretation versus temperature measurement analysis.

This study assessed electronic thermography as a diagnostic alternative for evaluation of temporomandibular disorders. The study populations consisted of 50 temporomandibular joint patients having internal derangement or osteoarthrosis and 30 normal temporomandibular joint subjects. An Agema 870 thermovision unit was used for analysis. Diagnostic evaluations by expert interpreters were made using standard procedures. Thermography measurements included mean absolute temperature measurements and right-left temperature differences for five anatomic zones and four spot areas. Statistical analysis of data included both linear discriminant analysis and classification-tree analysis. Results indicated that when differentiating between "abnormal" and "normal" temporomandibular joints using classification-tree analysis, correct classifications were made in 89% of the cases and observer diagnostic accuracy was 84%. When evaluating for specific diagnoses (eg, osteoarthrosis, internal derangement, or normal temporomandibular joint), correct classifications using classification-tree analysis were made in 73% of the cases and observer evaluation was correct in 59%. The three best temperature measures found were: (1) delta T of the zone immediately overlying the temporomandibular joint; (2) the zone temperature of the half-face; and (3) the spot temperature anterior to the external auditory meatus. Additional studies are needed before thermographic diagnosis of craniomandibular disorders is accepted clinically.

Zidovudine therapy, CD4+ and CD8+ counts are associated with a longer survival following AIDS onset.

In 60 patients followed from the onset of acquired immunodeficiency syndrome (AIDS) to death, survival was determined by Cox Proportional Hazards Analysis in relationship to seven variables: time-dependent CD4+ and CD8+ peripheral lymphocyte counts, zidovudine treatment, cytomegalovirus (CMV) retinitis, time from AIDS onset, calendar year of AIDS onset (cohort effect), and age. Two significant prognostic variables were identified: zidovudine therapy and either CD4+ or CD8+ counts (the latter could not be distinguished due to concomitant high correlation). Treatment with zidovudine reduced the death rate by 75% compared to no treatment. When included in a proportional hazards regression with all covariates except for the other T lymphocyte count, every increase in CD4+ count of 10 cells was equivalent to a decline in the mortality rate by 13% (p = 0.046), and every increase in CD8+ count of 10 cells lowered the mortality by 1.4% (p = 0.0031). Patients treated with zidovudine and without CMV retinitis showed the slowest decline of both CD4+ and CD8+ counts. Both CD4+ and CD8+ levels are useful predictors of survival in patients with AIDS.

A laser-powered hydrokinetic system for caries removal and cavity preparation.

BACKGROUND: Laser systems have been developed for the cutting of dental hard tissues. The erbium, chromium:yttrium-scandium-gallium-garnet, or Er,Cr:YSGG, laser system used in conjunction with an air-water spray has been shown to be efficacious in vitro for cavity preparation. METHODS: The authors randomly selected subjects for cavity preparation with conventional air turbine/bur dental surgery or an Er,Cr:YSGG laser-powered system using a split-mouth design. They prepared Class I, III and V cavities, placed resin restorations and evaluated subjects on the day of the procedure and 30 days and six months postoperatively for pulp vitality, recurrent caries, pain and discomfort, and restoration retention. Sixty-seven subjects completed the study. RESULTS: There were no statistical differences between the two treatment groups for the parameters measured with one exception; there was a statistically significant decrease in discomfort levels for the laser system at the time of cavity preparation for subjects who declined to receive local anesthetic. CONCLUSIONS: The Er,Cr:YSGG laser system is effective for preparation of Class I, III and V cavities and resin restorations are retained by lased tooth surfaces. CLINICAL IMPLICATIONS: Hard-tissue cutting lasers are being introduced for use in operative dentistry. In this study, an Er,Cr:YSGG laser has been shown to be effective for cavity preparation and restoration replacement.

The incidence of parasomnias in child bruxers versus nonbruxers.

Bruxism in children has been reported to occur in association with certain parasomnias (i.e., sleep talking, bed wetting). Various dental, medical, neurological, and psychological risk factors also have been correlated with bruxism. A case-control study was therefore conducted to test the null hypothesis that there is no difference between bruxers and nonbruxers in the occurrence rate of other parasomnias and these reported risk factors. A 54-item survey questionnaire was developed and mailed to 342 pediatric patients, half of whom were avowed to be bruxers by their parents. These patients were selected randomly from a private pediatric practice in Northern California. One-hundred fifty-two subjects (77 bruxers and 75 controls) returned the questionnaire, and stepwise logistic regression analysis revealed that five of the 54 factors (nocturnal muscle cramps, bed wetting, colic, drooling while sleeping, and sleep talking) showed significant differences between bruxers and controls (odds ratios ranged from 3.11 to 1.95). These findings strongly suggest the possibility of a common sleep disturbance underlying these nonsleep-stage specific parasomnias.

Change in mandibular trabecular pattern and hip fracture rate in elderly women.

OBJECTIVES: To determine if alterations of trabecular pattern, or the rate of change of jaw trabeculae, are associated with rate of hip fracture. METHODS: Participants in a population-based study of residents of a California retirement community (Leisure World Cohort Study) were asked for permission to obtain their dental radiographs. Periapical radiographs were retrieved on 598 women (average age at time of first radiograph=77 years). Several measurements of trabecular pattern (strut analysis), textural properties (run-length analysis) and Fourier analysis were made in several anatomical regions of the jaw. These trabecular features and clinical information self-reported by subjects in the early 1980s were examined for association with hip fracture rate using Cox proportional-hazard regression. RESULTS: Rate of hip fracture increased with decreasing average length of node-to-terminus struts in the mandibular incisor region. Each 0.01 mm per year decrease in the average length of node-to-terminus struts increased hip fracture rate by a factor of 2.9 (P=0.02, accuracy=73%). Inclusion of clinical parameters improved the predictive model compared with use of the radiographic parameter alone (accuracy=79%). Similar results were seen for percent change per year in this parameter. CONCLUSIONS: Changes in radiographic trabecular structure, augmented with clinical information, are predictive of hip fracture in elderly women. Further refinement of both the radiographic and clinical parameters may lead to a screening process accessible to a large number of women and to early diagnosis and treatment of osteoporosis.

Subjective judgments of speech clarity measured by paired comparisons and category rating.

OBJECTIVE: The purpose of this study was to compare listeners' subjective judgments of speech clarity via paired comparisons and category rating using stimulus conditions that varied in the relative spacing between stimulus items, producing either a wide or narrow range of performance. DESIGN: Subjective judgments of speech clarity were measured via paired comparisons and category rating in 12 normal-hearing (Experiment 1) and eight hearing-impaired adults (Experiment 2). Sentences processed by six band-pass filters that increased monotonically in Articulation Index (AI) estimates constituted the stimuli to be judged. Using subsets of three filters from the group of six, subjective judgments were additionally obtained for stimulus conditions in which the performance ranges were wide (large differences in AI) and narrow (small differences in AI). RESULTS: Speech clarity judgments obtained by paired comparisons and category rating were highly related to the AI estimates both for normal-hearing and hearing-impaired subjects. When the performance range was wide, both methods provided similar judgments for the normal-hearing subjects. For the hearing-impaired subjects, paired comparisons were more sensitive than category rating. When the performance range was narrow, paired comparisons were more sensitive than category rating in differentiating between filters for both groups of subjects. This difference was less obvious for the normal-hearing subjects when paired comparison data were converted to a scale comparable to the category ratings. Large between-subject variability was evident for the hearing-impaired subjects on the psychophysical scaling procedures, most notably for category rating. CONCLUSIONS: When judging the clarity among stimulus items where performance varied over a wide range, both category rating and paired comparisons provided comparable judgments for normal-hearing listeners. For conditions in which perceptual differences between stimulus items were restricted either by the choice of conditions or by the effects of sensorineural hearing loss, the method of paired comparisons was the more sensitive procedure.

Prediction of efficacy of bitewing radiographs for caries detection.

Although bitewing (BW) radiographs play an indispensable role in the detection of interproximal caries, it is not always clear when they should be made. The present study was designed to test the hypothesis that a person's caries and restorative history may be predictive of his or her caries future. Full-mouth radiographic examinations (FMX) and subsequent BW radiographs from 349 adults (age 20 or more) selected at random were examined. Possible risk factors for caries recorded for each patient included the number and type of carious lesions and the restorative experience of the patient. Linear logistic regression models were evaluated to estimate the efficacy of the possible risk factors as predictors of the presence of caries on the BW radiographs. Of the 349 adults examined, 91 (26%) had one or more new carious lesions at the time of their BW examination. The probability of caries in this population at the time of the BW examination increases both with lengthening interval between the FMX and the BW radiographs and with the number of restorations at the time of FMX. A regression model was adopted that estimates the probability of caries being detected on BW radiographs. We found that to provide the most good for the most patients (minimize cost), the threshold level for ordering follow-up radiographs should be when the probability of detecting caries is 5%. It may be seen that even when a person has no caries or restorations at the time of the FMX there will be a 5% chance that BW radiographs will reveal the presence of caries 1.5 years later. The 5% threshold is reached sooner in the presence of caries or restorations.

Human immunodeficiency virus type 1 antigenaemia is enhanced in patients with disseminated cytomegalovirus infection and deficient T lymphocytes.

We have studied 61 patients with the acquired immunodeficiency syndrome (AIDS) regarding the relationships between disseminated cytomegalovirus (CMV) infection with CMV retinitis, HIV1 antigenaemia and CD4+ and CD8+ T-cell deficiency. HIV1 p24 antigenaemia was present in all patients with CMV retinitis (at a high concentration), but in only 28% of patients without retinitis (at a low concentration). Compared to patients without retinitis, those patients who developed retinitis had lower CD4+ and CD8+ prior to and during AIDS. CMV may contribute to deficiencies of T lymphocytes in patients with AIDS.