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Biomedical subjects

J C Burns

Publications and source records attributed to J C Burns.

At least 19 recordsLinked to original sources
PubMed1992

The prevalence of oral lesions in smokeless tobacco users and an evaluation of risk factors.

BACKGROUND: The widespread use of smokeless tobacco (ST) has prompted concern in regard to the development of oral lesions in long-term users. METHODS: For inclusion in the current study, a subject must have used an ST product, either snuff or chewing tobacco, for at least 6 months. The subjects were recruited by advertising, and none was referred for the evaluation of an oral lesion. The following were performed on all subjects: assessment of exposure to ST, cigarettes, and alcohol; examination of the oral cavity; a biopsy, if an oral lesion was found; and analysis of a blood sample for beta-carotene. The dietary intake of most of the subjects was analyzed. RESULTS: Of the 347 ST users, all of whom were white male subjects, 45 (13.0%) had an oral lesion. Thirty-five of the lesions were hyperkeratosis and 10 were epithelial dysplasia. CONCLUSIONS: Snuff exposure was associated significantly with the presence of an oral lesion (P < 0.0001). A decreased vitamin C intake also was found among the ST users with oral lesions (P < 0.01). The ST users with epithelial dysplasia, as compared with those with hyperkeratotic lesions, were slightly older, had a lower intake of vitamin C (P < 0.05), and were more likely to have used chewing tobacco than snuff.

Adult↗
PubMed1992

Effect of high doses of intravenously administered immune globulin on natural killer cell activity in peripheral blood.

Because Kawasaki disease is a disorder characterized by lymphocyte activation and immune complex destruction of endothelial cells, we examined the effect of administration of high doses of intravenously administered immune globulin (IVIG) on a lymphocyte population with affinity for endothelial cells: the natural killer cells. We found that administration of high doses of IVIG resulted in a significant increase in the activity of natural killer cells and in the numbers of circulating CD16+ cells. Furthermore, a study of patients treated with IVIG for seizure disorders suggests that this effect of IVIG on circulating NK cells is not unique to patients with Kawasaki disease. The beneficial effect of IVIG in the treatment of Kawasaki disease may be due to the ability of IVIG to inhibit interaction between natural killer cells and endothelial cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1992

Comparison of oral carcinomas in smokeless tobacco users and nonusers.

Biopsy reports of squamous cell carcinoma (SCC) and verrucous carcinoma (VC) were retrospectively evaluated to determine the prevalence of smokeless tobacco (ST) use and to ascertain if any clinical or histologic differences existed when comparing ST users with nonusers. Of the 874 SCC cases, 12 patients (1.4%) were ST users as compared with 7.7% (10 of 129) of the VC patients. The carcinomas in ST users, either SCC or VC, were diagnosed at a later age and were more likely to occur in the buccal mucosa/vestibule area. The SCCs in ST users were more often histologically well differentiated. Because of the anatomic site predilection, it appears probable that ST use is a causative factor in the development of some cases of oral carcinoma.

Adolescent↗
PubMed1992

Diet characteristics, digesta kinetics, and dry matter intake of steers grazing eastern gamagrass.

Eastern gamagrass (Tripsacum dactyloides [L.] L.) has attracted attention as a forage crop, but information on its use is lacking. This 2-yr study compared diet quality, ingestive mastication, and ADG by steers grazing eastern gamagrass (GG), flaccidgrass (Pennisetum flaccidum Griseb.), and Tifton 44 bermudagrass (Cynodon dactylon [L.] Pers.). The design was a randomized complete block with two agronomic replicates. The diet selected by steers from GG in May did not differ from the diet selected by steers from flaccidgrass (FG) for IVDMD (77.3%), NDF (44.0%), CP (19.5%), and mean and median particle sizes of the ingesta (1.8 and 1.4 mm). In July, GG diets had three percentage units less IVDMD (P less than .05), 8.4 percentage units more NDF (P less than .05), and 4.5 percentage units less CP (P = .07) than the mean of FG and bermudagrass (BG). The canopy (July) of GG had the greatest proportion of its DM as leaf (59 vs 26% for FG and 22% for BG) and the least proportion as stem (25 vs 40% for FG and 59% for BG). Mean particle size (millimeters) of masticates differed (P = .05) among forages with GG greatest (2.2), followed by FG (1.6), and BG particles were smallest (1.2). Proportion of large (greater than or equal to 2.8 mm), medium (less than 2.8 greater than or equal to .5 mm), and small (less than .5 mm) particles of the masticate DM, and their IVDMD and NDF concentration, interacted with species (P less than .05). Gamagrass masticate had the greatest proportion (28%) of large particles and BG the greatest proportion (23%) of small particles. The least IVDMD occurred for large particles of BG (62.5%) and small particles of GG (63.8%). Digesta kinetics did not differ among species. Characteristics of GG yielded steer ADG of .82 vs .67 kg for FG and .30 kg for BG (P = .05).

Animal Feed↗
PubMed1992

Evaluation of the Captec chrome controlled-release device for the estimation of fecal output by grazing sheep.

Three grazing experiments were conducted to compare actual fecal output (FO) by sheep, determined with fecal collection bags, to fecal output predicted using Captec chromic oxide (Cr2O3) controlled-release capsules. In Exp. 1, 14 crossbred wethers dosed with controlled-release Cr2O3 capsules rotationally grazed four paddocks of alfalfa (Medicago sativa L.) for 18 d. Total fecal collection and grab samples were taken daily from each animal; feces were dried and assayed for Cr. From d 5 to 12 after dosing, mean actual FO (429 +/- 9.6 g of DM/d) differed (P less than .001) from FO predicted by the capsule (463 +/- 12.8 g of DM/d). The correlation between actual and predicted FO was r = .59. When data were averaged by day, the correlation increased to .82. In Exp. 2, Tifton 44 bermudagrass (Cynodon dactylon [L.] Pers.) was strip-grazed for 30 d by the same 14 wethers used in Exp. 1. Mean actual FO (369 +/- 5.1 g of DM/d) differed (P less than .0001) from predicted FO (415 +/- 9.3 g of DM/d), with a correlation of .60. In Exp. 3, 72 crossbred lambs were blocked by weight (light and heavy) and assigned to six groups of eight wethers (four with fecal bags) and four ewes, allotted randomly to three stocking rates (74, 99, and 148 sheep/ha). Sampling occurred from d 6 to 10 after dosing (Period 1) and d 20 to 24 after dosing (Period 2).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1992

Audiologic profiles of children with Kawasaki disease.

Kawasaki disease (KD) is an idiopathic vasculitis associated with systemic inflammation and profound immunoregulatory changes. Recent reports from Japan and the United States have documented the association of sensorineural hearing loss (SNHL) with acute KD. To further characterize the nature and prevalence of this complication, we prospectively evaluated the hearing of 40 consecutive patients with acute KD at a single institution. Standard audiometric procedures were used, including visual reinforcement audiometry and play audiometry. Auditory brainstem response (ABR) testing using clicks and tone pips (1000-4000 Hz) was performed in patients with abnormal or unreliable results on behavioral audiometry. Acoustic immittance measurements were obtained on all patients. Of the 23 males and 17 females (mean age 3.2 +/- 2.3 years, range 0.6-11.1 years), all but three were evaluated and treated with aspirin and intravenous gama globulin within 1 month of onset of fever. Seven children had test results suggesting sensorineural threshold shifts, 16 had normal hearing, and 14 had inconclusive hearing evaluations. Laboratory data in patients with hearing threshold shifts revealed significantly longer duration of fever (4.1 +/- 1.0 versus 1.9 +/- 0.5 days), and a tendency for higher temperatures and white blood cell counts at diagnosis compared to those with normal hearing. Results suggest that transient as well as persistent SNHL may be associated with the acute vasculitis of KD, and may be associated with laboratory markers indicating more severe systemic inflammation. Audiologic screening should be considered for all patients following KD.

Aspirin↗
PubMed1991

A single intravenous infusion of gamma globulin as compared with four infusions in the treatment of acute Kawasaki syndrome.

BACKGROUND: Treatment of acute Kawasaki syndrome with a four-day course of intravenous gamma globulin, together with aspirin, has been demonstrated to be safe and effective in preventing coronary-artery lesions and reducing systemic inflammation. We hypothesized that therapy with a single, very high dose of gamma globulin would be at least as effective as the standard regimen. METHODS: We conducted a multicenter, randomized, controlled trial involving 549 children with acute Kawasaki syndrome. The children were assigned to receive gamma globulin either as a single infusion of 2 g per kilogram of body weight over 10 hours or as daily infusions of 400 mg per kilogram for four consecutive days. Both treatment groups received aspirin (100 mg per kilogram per day through the 14th day of illness, then 3 to 5 mg per kilogram per day). RESULTS: The relative prevalence of coronary abnormalities, adjusted for age and sex, among patients treated with the four-day regimen, as compared with those treated with the single-infusion regimen, was 1.94 (95 percent confidence limits, 1.01 and 3.71) two weeks after enrollment and 1.84 (95 percent confidence limits, 0.89 and 3.82) seven weeks after enrollment. Children treated with the single-infusion regimen had lower mean temperatures while hospitalized (day 2, P less than 0.001; day 3, P = 0.004), as well as a shorter mean duration of fever (P = 0.028). Furthermore, in the single-infusion group the laboratory indexes of acute inflammation moved more rapidly toward normal, including the adjusted serum albumin level (P = 0.004), alpha 1-antitrypsin level (P = 0.007), and C-reactive protein level (P = 0.017). Lower IgG levels on day 4 were associated with a higher prevalence of coronary lesions (P = 0.005) and with a greater degree of systemic inflammation. The two groups had a similar incidence of adverse effects (including new or worsening congestive heart failure in nine children), which occurred in 2.7 percent of the children overall. All the adverse effects were transient. CONCLUSIONS: In children with acute Kawasaki disease, a single large dose of intravenous gamma globulin is more effective than the conventional regimen of four smaller daily doses and is equally safe.

Acute Disease↗
PubMed1991

Clinical and epidemiologic characteristics of patients referred for evaluation of possible Kawasaki disease. United States Multicenter Kawasaki Disease Study Group.

STUDY OBJECTIVES: (1) To determine those diseases that most often mimic Kawasaki disease (KD) in the United States. (2) To examine the physical findings and laboratory studies that influenced experienced clinicians to exclude the diagnosis of KD. (3) To compare epidemiologic features of patients with KD and patients referred for evaluation of possible KD in whom alternative diagnoses were established. DESIGN: Case comparison study. SETTING: Seven pediatric tertiary care centers. PATIENTS: Consecutive sample of 280 patients with KD and 42 comparison patients examined within the first 14 days after onset of fever. MEASUREMENTS AND MAIN RESULTS: (1) Infectious diseases, particularly measles and group A beta-hemolytic streptococcal infection, most closely mimicked KD and accounted for 35 (83%) of 42 patients in the comparison group. (2) The standard diagnostic clinical criteria for KD were fulfilled in 18 (46%) of 39 patients in whom other diagnoses were established. (3) Patients with KD were significantly less likely to have exudative conjunctivitis or pharyngitis, generalized adenopathy, and discrete intraoral lesions, and more likely to have a perineal distribution of their rash. The patients with KD were also more likely to have anemia and elevated erythrocyte sedimentation rate; leukocyte count less than 10 X 10(3)/mm3 and platelet count less than 200 X 10(3)/mm3 were significantly less prevalent in patients with KD. (4) Residence within 200 yards of a body of water was more common among KD patients. CONCLUSIONS: (1) Measles and streptococcal infection should be excluded in patients examined for possible KD. (2) Laboratory studies that may be useful in discriminating patients with KD from those with alternative diagnoses include hemoglobin concentration, erythrocyte sedimentation rate, and serum alanine aminotransferase activity. (3) Residence near a body of water may be a risk factor for the development of KD.

Age Factors↗
PubMed1991

Decreased protein binding of salicylates in Kawasaki disease.

Because patients with Kawasaki disease have low serum concentrations of salicylates despite high doses, and because the free (unbound) drug is responsible for the pharmacologic effects of salicylates, we assessed salicylate protein binding in patients with Kawasaki disease. During the acute phase of the disease, protein binding of salicylate in 36 children with Kawasaki disease was 73 +/- 12%, significantly lower than during the subacute phase (90.4 +/- 8.7%; p less than 0.0005). Mean serum albumin concentration was 29.2 +/- 6.4 gm/L during the acute phase and 36.7 +/- 7.8 gm/L during the subsequent subacute phase (p less than 0.005). Salicylate protein binding was affected independently by both serum albumin and total salicylate levels. During the acute phase of Kawasaki disease, children had an average twofold increase in free salicylate compared with normoalbuminemic control subjects. A nomogram has been devised to derive free salicylate levels from the known total salicylate and serum albumin concentrations.

Acute Disease↗
PubMed1991

Altered lipid profile after Kawasaki syndrome.

BACKGROUND: Delineation of lipid values in children after Kawasaki syndrome is important because of the predilection of this disease for the coronary arteries. METHODS AND RESULTS: We measured plasma concentrations of total cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides using enzymatic methods in 105 patients with a history of Kawasaki syndrome. Measurements were obtained during six time periods: 10 days or less, 11-31 days, 1-3 months, 3-12 months, 1-3 years, and more than 3 years. Total cholesterol was depressed in the first interval (122.0 +/- 19.8 mg/dl, mean +/- SD), but the mean values were normal in all periods after clinical recovery (overall mean, 149.0 +/- 24.0 mg/dl). High density lipoprotein cholesterol was also depressed in the first interval (15.2 +/- 9.9 mg/dl); although high density lipoprotein cholesterol increased significantly with duration since disease onset (p less than 0.001), it remained significantly lower than expected (p less than 0.001), even in the latest interval (47.2 +/- 10.9 mg/dl). Nonfasting triglyceride levels were high (162.5 +/- 63.4 mg/dl) in the first interval and then diminished steadily with time, but this relation did not achieve statistical significance. We compared adjusted lipid levels (z scores) of 46 Kawasaki patients after clinical recovery with those of their parents; patients had similar total cholesterol levels but significantly lower high density lipoprotein cholesterol levels (p = 0.021 for mothers, p = 0.001 for fathers). Mean high density lipoprotein cholesterol after clinical recovery tended to be lower in patients with persistent coronary abnormalities than in those without such lesions (p = 0.085). CONCLUSIONS: Kawasaki syndrome is associated with important abnormalities in lipid metabolism. Continued long-term surveillance of this population is necessary to monitor lipid levels and their relation to future development of coronary atherosclerosis.

Adolescent↗
PubMed1991

Effects of grass species on grazing steers: I. Diet composition and ingestive mastication.

In traditional grazing trials, per animal and per hectare productivity are determined, but pasture and animal measurements are generally inadequate to address reasons for different treatment responses. This 2-yr study examined the diet and diet characteristics of steers grazing tall fescue (Festuca arundinacea Schreb.), switchgrass (Panicum virgatum L.), flaccidgrass (Pennisetum flaccidum Griseb.), and bermudagrass (Cynodon dactylon [L.] Pers.) pastures. A randomized complete block design was used with two agronomic replicates. In vitro DM disappearance (IVDMD) of masticates from tall fescue (TF), switchgrass (SG), and flaccidgrass (FG) generally were similar; all exceeded 70% (70.3 to 79.9%), except for bermudagrass (BG), which was lowest (63.5 to 65.0%). Sieving the masticate DM showed BG to contain the highest proportion (20 to 29%) of particles passing a .5-mm sieve and the lowest proportion (6 to 8%) of particles retained on a 2.8-mm sieve. This resulted in BG having the smallest mean (1.29 mm) and median (1.08 mm) particle sizes in yr 1 and a mean (1.10 mm) and median (.91 mm) particle size smaller than SG in yr 2. Except for BG, the IVDMD of the masticate DM was lowest for small particles. Canopies showed BG and SG to have the highest proportion of stem (47 and 52%, respectively); the BG canopy was composed of fractions that were consistently lowest in IVDMD. In general, BG offered the grazing animal a canopy inferior in IVDMD concentration and had canopy characteristics that limited the animals' selection of a diet with quality as high as that of TF, SG, or FG.

Animal Feed↗
PubMed1991

Effects of grass species on grazing steers: II. Dry matter intake and digesta kinetics.

Animal responses to treatments in grazing experiments frequently remain unexplained because of inadequate pasture and(or) animal measurements. This 2-yr study examined DMI, gastrointestinal tract fill of undigested DM (FILL), rate of digesta passage (ROP), and digesta mean retention time (MRT) for steers grazing tall fescue (Festuca arundinacea Schreb.), switchgrass (Panicum virgatum L.), flaccidgrass (Pennisetum flaccidum Griseb.), and bermudagrass (Cynodon dactylon [L.] Pers.). A randomized complete block design was used with two agronomic replicates. Comparisons in June (yr 1) among continuously grazed switchgrass (SG), flaccidgrass (FG), and bermudagrass (BG) or in May (yr 2) among tall fescue (TF), SG, and FG showed similar digesta kinetics, but different DMI (kg.d-1.100 kg BW-1), among these forages within each sampling. In the June evaluation, the DMI of SG and FG were similar (means = 3.09), DMI of bermudagrass (BG) was lowest (2.23), and fecal DM output (FO) was similar among forages. In the May evaluation, DMI by steers grazing SG (3.90) was higher than that by steers grazing FG (2.97); DMI of tall fescue (TF) was intermediate (3.41) but similar to DMI of FG. Differences in DMI were due to differences in diet in vitro DM disappearance (IVDMD) rather than to differences in digesta kinetics. In July (yr 2), the MRT was highest for BG (84 h) and similar for SG and FG (57 h). Steers grazing different forages exhibited similar ROP and FILL, but FO (kg.d-1.100 kg BW-1) among steers varied (.37 for steers fed BG; .74 for steers fed SG and FG).(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Feed↗
PubMed1991

Image analysis and nonlinear modeling to determine dimensions of wet-sieved, masticated forage particles.

A procedure to estimate dimensions of digesta particles was developed and evaluated. After wet sieving, particles of masticated switchgrass and bermudagrass hays retained on sieves with apertures of 1.0 mm2 or larger were placed on moist white filter paper, separated manually, and photographed. Photographs were scanned with a flat-bed scanner, scaled to size, and digitized. Projected area, perimeter, length, and width of particles were determined by a microcomputer system. Variables derived for each particle included the form factor, which was defined as (4 x pi x area)/perimeter2, and each particle's length: width ratio. Ninety-three percent of data from two trials with steers had significant lack of fit (P less than .05 to P less than .0001) to normal, lognormal, Weibull, or gamma distributions. As an alternative, individual particle measurements were summed on a cumulative percentage basis for each variable and were fit to an inverted Gompertz function to estimate median, mode, and mean dimensions of scanned particles. Estimates from the equation fit the distribution well; asymptotic SE averaged 3.5 and 1.4% of parameter means for dimensions of masticated switchgrass and bermudagrass hay particles, respectively. No analytic solution exists for the mean, which must be estimated numerically, but analytic solutions are available for the median and mode. Use of this equation will prevent bias caused by lack of fit to a particular distribution and yield more accurate estimates of mean particle dimensions than arithmetic means.

Animal Feed↗