The applicability of the theory of planned behavior to the intention to quit smoking across workplaces in southern Taiwan.

An examination of the applicability of the theory of planned behavior (TPB) to the intention to quit smoking across workplaces was conducted. Subjects were randomly selected from three workplaces in southern Taiwan. Those from a large public steel-manufacturing company were used for model building, and those from two private auto-parts-manufacturing companies served to cross-validate the model. Eligible subjects were divided into three study samples: a learning sample and two test samples. Three predictors--priority of quitting, past behavior (measured as previous quit attempt), and habit (measured as nicotine dependence)--were added to the TPB model. The results of this study show that TPB based on the learning sample fit well in another sample from the same workplace but poorly in other workplaces. When priority of quitting and past behavior were added to the TPB model, prediction to other workplaces significantly improved. Habit had no significant contribution to the intention to quit in the TPB model. Detailed discussions of the results are provided.

A new experimental model for studying the response of periodontal ligament cells to hydrostatic pressure.

An apparatus was developed to apply positive or negative hydrostatic pressure dynamically to periodontal ligament (PDL) cells in vitro. The objective of this investigation was to construct this apparatus and to determine its effects on PDL cells. Human PDL cells were collected from freshly extracted premolars. At the sixth passage, the cells were mechanically stimulated by this apparatus at different magnitudes of continuous positive or negative hydrostatic pressures (PHP or NHP, respectively). The application of PHP between 0.3 and 30 gm/cm2 significantly enhanced prostaglandin E (PGE) production and intracellular cyclic AMP (cAMP) of the cells. In contrast, perturbation by NHP significantly decreased PGE production and intracellular level of cAMP. Proliferation rate increased significantly at 24 and 48 hours due to stimulation of these cells with -30 gm/cm2 of NHP. Challenging these cells with +30 gm/cm2 of PHP significantly decreased the proliferation rate of these cells at 24 and 48 hours. Stimulation by PHP between +30 to +600 gm/cm2 increased cell length and width and appeared to increase surface area attachment to the bottom of the culture dishes. In contrast, NHP (between -30 and -600 gm/cm2) decreased these dimensions and appeared to reduce the surface area of attachment. These results indicate that this type of mechanical perturbation of PDL cells produces physiologic responses and is not detrimental to their vitality.

A two-month study of the effects of oral irrigation and automatic toothbrush use in an adult orthodontic population with fixed appliances.

Forty-seven adult orthodontic patients with fixed orthodontic appliances were divided into three study groups: (1) oral irrigation with automatic toothbrush, (n = 16); (2) oral irrigation with manual toothbrushing, (n = 16); (3) control group with continued normal toothbrushing only, (n = 15). Gingival and plaque indices, bleeding after probing, and gingival sulcus depths were assessed at baseline, 1-month, and 2-month periods. Marked and significant gingival and plaque improvements from baseline were measured in all three study groups. After 1 to 2 months use of the automatic toothbrush and/or the oral irrigation device, there was a significant reduction in plaque when compared with the control group who used only the manual toothbrush (p = 0.026). Also, there was a significant reduction in gingival inflammation (p = 0.045) and evidence for reducing bleeding after probing (p = 0.037). No significant differences were found in probe depths among the three study groups, however, use of both devices reduced the pocket depth significantly from baseline by 0.5 mm (p < 0.0002). For this population of orthodontic patients, significant reductions in plaque, gingival inflammation, and a tendency for reduced bleeding after probing occurred in both groups with the power device. These improvements were most attributable to the effect of the oral irrigation device.

99mTc-medronate uptake in the temporomandibular joints of young rats treated with a mandibular hyperpropulsor.

To correct maxillomandibular sagittal discrepancies in growing children, most functional appliances position the mandible more anteriorly than its habitual relation with the maxilla. The aim of this study was to evaluate the effects of such a procedure on the mineralization of the temporomandibular joints in young growing rats. Temporomandibular joint uptake of a radioactive bone marker, technetium 99m methylene diphosphonate (99mTc-MDP), was measured over time as a hyperpropulsor appliance was being worn intermittently 12 hours/day. As the uptake of 99mTc-MDP decreased in control animals, it increased significantly in the joints of treated rats before returning to the baseline level after 5 weeks of treatment. These results suggest that intermittent anterior positioning of the mandible induces a high rate of bone and cartilage remodeling in the joints of growing rats and that bone-seeking radiopharmaceutical uptake, with 99mTc-MDP, may be a useful technique to monitor joint adaptation to an experimental functional change.

Injury and disability in matched men's and women's intercollegiate sports.

Eight matched men's and women's intercollegiate varsity teams were studied prospectively for one academic year to determine the incidence of athletic injury and resulting disability. Sports in which both men and women participated in a comparable manner were chosen: basketball, fencing, gymnastics, swimming, tennis, indoor track, outdoor track, and volleyball. Men (232) and women (150) were injured at comparable rates, 42 percent versus 39 percent. When adjusted for exposure time, seven of the eight sports continued to show similar injury rates. Women gymnasts, however, experienced .82 injuries per 100 person-hours of exposure as compared to .21 injuries for the men (p = .0001). Disability was greater in women gymnasts, 7.44 days per 100 person-hours versus 1.15 days for men (p = .0004). Percent of season lost to injury was also greater for women gymnasts. Types and sites of injury were similar for men and women, with sprains and strains accounting for over half of all injuries. We found no evidence for gender differences in matched sports except for gymnastics, in which technically diverse events may have accounted for the differences observed.

Interactive effects between cytokines on PGE production by human periodontal ligament fibroblasts in vitro.

Mononuclear cell production of cytokines that stimulate fibroblast production of prostaglandin E (PGE) is an important mechanism by which mononuclear cells regulate fibroblast function. The objective of this investigation was to determine the effects of the cytokines interleukin 1 beta (IL-1 beta), interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma), alone or in paired combinations, on PGE production by near-confluent human periodontal ligament (PDL) fibroblasts in vitro. Premolars extracted in the course of orthodontic treatment were used for this study. Fibroblast cultures, free of epithelial cells, were obtained after the fourth subculture by the use of accurately-timed trypsin treatment. Cells in the fourth to sixth passage, incubated in DMEM supplemented with 10% equine serum, were used for these experiments. Cells (1 x 10(5)) were seeded in 12- x -75-mm tissue culture tubes and incubated with various doses of IL-1 beta, IL-1 alpha, TNF-alpha, and IFN-gamma, alone or in specific combinations, for 15 min, two, 12, 24, and 72 h. PGE concentrations in the media were measured by radio-immunoassay. The results showed that human PDL fibroblasts responded to the administration of cytokines by an elevation in the synthesis of PGE in a dose- and time-related fashion. The increase in PGE production was inhibited by the addition of indomethacin. The interactions between these cytokines varied in degree, depending on the particular combinations of cytokines. In addition, the administration of cytokine combinations was found to be additive, synergistic, subtractive, or suppressive on the production of PGE by PDL fibroblasts, depending on the duration of incubation. These experiments demonstrate the importance of the consideration of the interplay between cytokines produced by mononuclear cells on the mechanisms that regulate the functions of PDL fibroblasts.

Effects of cytokines on prostaglandin E and cAMP levels in human periodontal ligament fibroblasts in vitro.

The stimulation of PGE synthesis and cAMP production by cytokines have important physiological effects in many target tissues. The effects of interleukin-1 alpha and -1 beta, tumour necrosis factor-alpha and interferon-gamma on PGE and cAMP production by periodontal ligament fibroblasts were studied. Fibroblasts in the 4th-6th passage, grown and maintained in DMEM supplemented with 10% equine serum, were incubated with graded doses of the various cytokines for 0.25, 0.5, 1.2, 4, 24, 48 or 72 h. At the end of each incubation, PGE in the medium and the cellular content of cAMP were evaluated by a combined immunohistochemical microphotometric procedure, and conventional radiometric assays. The fibroblasts responded to all the cytokines with a dose- and time-related increase in the levels of PGE and cAMP. Such increases were inhibited by the inclusion of indomethacin in the medium. The addition of exogenous PGE reversed that inhibition in respect of cAMP production. Immunohistochemical localization showed PGE predominantly in the cytoplasm and cAMP in the nucleus. These findings indicate that: (1) human periodontal ligament fibroblasts respond to these cytokines by increased synthesis of PGE and the production of cAMP; and (2) the cAMP production is secondary to the PGE synthesis. They suggest that these cytokines may regulate the function of these fibroblasts in physiological remodelling of the periodontium, as well as in inflammatory reactions.

Effects of parathyroid hormone and cytokines on prostaglandin E synthesis and bone resorption by human periodontal ligament fibroblasts.

Cultured human periodontal ligament fibroblasts showed synergistic elevations in the synthesis of prostaglandin E and production of cAMP by the administration of parathyroid hormone and cytokines (interleukin 1 alpha, -1 beta, or tumour necrosis factor-alpha). Unstimulated conditioned media derived from these fibroblasts contained bone-resorbing activity. In addition, conditioned media generated by cytokine-or parathyroid hormone-treated fibroblasts showed further increases in bone-resorbing activity. The effects were additive when the hormone was combined with either one of the cytokines in stimulating bone resorption. These findings suggest that the effect of parathyroid hormones and cytokines together on bone resorption can be mediated in part by human periodontal ligament fibroblasts via PGE production and subsequent PGE action on the osteoclasts.

The interactive effects of mechanical stress and interleukin-1 beta on prostaglandin E and cyclic AMP production in human periodontal ligament fibroblasts in vitro: comparison with cloned osteoblastic cells of mouse (MC3T3-E1).

Human periodontal ligament fibroblasts and a cloned osteogenic cell line (MC3T3-E1) were seeded (4 x 10(5) cells) on 60 mm Petriperm dishes, which have a flexible plastic growth surface. Cells were stretched by placing the dish on top of a spheroidal convex template, equilibrated to 37 degrees C. The amount of stretch was varied by changing the curvature of the template and calculated as percentage stretch. Both types of cell responded to mechanical stress by elevated synthesis of PGE and cAMP; the addition of interleukin-1 beta to mechanically stretched cells produced further elevation. Synergism between mechanical stress and interleukin-1 beta was found at certain lengths of incubation. The production of cAMP was secondary and dependent on the newly synthesized PGE, as shown in the presence of indomethacin. The two cell types were also different in terms of the timing of their response to mechanical stress and interleukin-1 beta. In the absence of stimuli, periodontal fibroblasts tended to produce PGE continually over time, whereas the MC3T3-E1 cells did not. However, both cell types had elevated PGE levels in response to the stimuli used in this experiment. Periodontal fibroblasts responded to mechanical stress and interleukin-1 beta with significant elevations of PGE as early as 15 min, whereas the MC3T3-E1 cells required 2 h to produce significant elevations for mechanical stress and 15 min for interleukin-1 beta. These findings indicate that the chemical and mechanical signals on these cells are mediated by surface receptors. Locally produced autocrine or paracrine factors can modify the effect of mechanical stress on periodontal and bone cells via the cAMP pathway.(ABSTRACT TRUNCATED AT 250 WORDS)

Illness and absence among wrestlers, swimmers, and gymnasts at a large university.

The object of this study was to document the prevalence of illness and absence in members of three men's intercollegiate athletic teams: varsity wrestling, swimming, and gymnastics. Team members (N = 87) were interviewed weekly in January and February during 8 weeks of their competitive season. Symptoms, signs, and their duration were recorded on a standard form, as well as the number of days of absence from at least one class or team practice or competition. Mean prevalence of illness was 54 per 100 persons during the first 5 weeks of the study and 30 per 100 persons during the last 3 weeks. Eight-six percent of the athletes had at least one respiratory illness during the 8 week period and 40% reported skin problems. There were no significant differences among teams for respiratory or skin problems. Gastrointestinal symptoms were significantly more frequent among swimmers than among wrestlers or gymnasts (chi 2 = 16.1, df = 2, P less than 0.001). During an illness, an athlete was less likely to miss class than practice or competition (chi 2 = 5.33, df = 1, P less than 0.05). We conclude that there were no significant differences in the prevalence of illness among the three teams except that swimmers had more gastrointestinal problems as well as a transient syndrome associated with abnormal water quality (pH) in the swimming pool.

Immunohistochemical assessment of the effect of chemical and mechanical stimuli on cAMP and prostaglandin E levels in human gingival fibroblasts in vitro.

These were evaluated by: (1) a combined immunohistochemical-microphotometric procedure (IH) and (2) conventional radiometric assays. Human gingival fibroblasts were in the sixth passage, grown and maintained in Dulbecco minimal essential medium (DMEM) supplemented with 10 per cent horse serum. For chemical and hormonal stimuli, cells (2 x 10(4] were seeded on tissue-culture chamber/slides, and incubated with graded doses of either parathyroid hormone (PTH) or prostaglandin E2 (PGE2) for assessment of their adenosine-3',5'-monophosphate (cAMP) levels, and with indomethacin or colchicine for their effect on PGE levels. For mechanical stimuli, cells (1 x 10(6] were seeded on culture dishes with a flexible plastic membrane and stretched for 5, 30, 60 or 120 min by placing the membrane over a convex surface and weighting the dish cover. After freeze drying, cells were stained by an immunoperoxidase technique for either cAMP or PGE, using monoclonal antibodies. The staining intensity of fibroblasts was determined at 600 nm wavelength. Per cent light absorbance of 15 cells in each slide was measured and the results tested by analysis of variance. The gingival fibroblasts responded to the drugs and hormones in a dose- and time-related fashion. Stretching significantly increased their synthesis of PGE with concomitant increase in cAMP. The IH results were compared with the radiometric assays to confirm the validity of this technique; both assays were valid for describing the quantitative responses of these cells to the stimuli. In particular, the IH method could localize those intracellular sites which demonstrated chances in relative cAMP and PGE concentrations in response to hormonal stimuli.

Municipal sewage sludge application on Ohio farms: health effects.

A 3-year prospective epidemiologic study was conducted on 47 farms receiving annual applications of treated sludge (average of 2-10 dry metric tons/ha/year) and 46 control farms in three geographic areas of Ohio. On the sludge-receiving farms 164 persons (78 families) and on the control farms 130 persons (53 families) participated by cooperating with monthly questionnaires concerning their health and their animals' health, annual tuberculin testing, and quarterly blood sampling for serological testing. The estimated risks of respiratory illness, digestive illness, or general symptoms were not significantly different between sludge farm and control farm residents. Similarly, there were no observed differences between disease occurrence in domestic animals on sludge and on control farms. No conversions from negative to positive tine test results occurred after sludge had been applied to the farms. The frequency of serological conversions (fourfold or greater rise in antibody) to a series of 23 test viruses and the frequency of associated illnesses were similar among persons on sludge and control farms. The absence of observed human or animal health effects resulting from sludge application in this study of Ohio farms was associated with low sludge application rates which were in accordance with Ohio and U.S. Environmental Protection Agency guidelines. Caution should be exercised in using these data to predict health risks associated with sludges containing higher levels of disease agents and with higher sludge application rates and larger acreages treated per farm than used in this study.

Weight loss in amateur wrestlers and its effect on serum testosterone levels.

Levels of nine serum hormones, six skin-fold sites, and body weight were measured in 19 male amateur wrestlers during their competitive season and again two months after the season. Percent of body fat was estimated from skin-fold thicknesses. Body weight, body fat, testosterone level, and prolactin level were significantly lower during the wrestling season. Low serum testosterone levels were significantly correlated with low body fat, large loss of body fat, and large weight loss. These findings suggest that the dietary restriction practiced by some wrestlers may affect serum testosterone levels adversely.

Anabolic steroid use and perceived effects in ten weight-trained women athletes.

Ten women athletes who consistently used anabolic steroids were interviewed about their patterns of drug use and the perceived effects. Anabolic steroids were used in a cyclical manner, often with several drugs taken simultaneously. All participants believed that muscle size and strength were increased in association with anabolic steroid use. Most also noted a deepening of the voice, increased facial hair, increased aggressiveness, clitoral enlargement, and menstrual irregularities. The participants were willing to tolerate these side effects but thought that such changes might be unacceptable to many women.

Hypolipidemic effects of clofibrate and selected chroman analogs in fasted rats: II. High sucrose-fed animals.

The hypolipidemic properties of ethyl 6-chlorochroman-2-carboxylate (II), 6-phenylchroman-2-carboxylate (III) and 6-cyclohexylchroman-2-carboxylate (IV) were compared to clofibrate (I) in sucrose-fed fasted male Sprague-Dawley rats. All compounds were administered at doses of 0.2 and 0.4 mmol/kg, orally, twice daily for 7 consecutive days. In this model, II was a more effective hypocholesterolemic drug than clofibrate, whereas III and IV were inactive. Chlorochroman II, like clofibrate, decreased serum alpha-lipoprotein cholesterol and pre-beta-lipoprotein triglyceride concentrations and concomitantly increased serum beta-lipoprotein triglyceride concentrations. In clofibrate-treated rats, serum free cholesterol concentrations increased concurrent with a reduction in serum lecithin: cholesterol acyltransferase activity, but no such correlation was observed for II. Only II lowered liver cholesterol levels and increased liver triglyceride levels. No consistent inhibition of liver microsomal 3-hydroxy-3-methylglutaryl-CoA reductase activity was observed with these analogs. The observed changes in triglyceride and cholesterol concentrations among serum lipoproteins were of a greater magnitude after chlorochroman II and clofibrate administration to sucrose-fed rats than in our previous studies using chow-fed fasted rats. These data suggest that chloro-substitution at the 6-position of the phenylchroman ring is important for hypolipidemic activity of these cyclic clofibrate analogs.

Injuries among wrestlers in school and college tournaments.

We studied four wrestling tournaments that totaled 1,049 participants of grade school, high school, and college age levels. Two clearly serious injuries occurred: a wrist fracture and an elbow dislocation. Knee and ankle sprains of mild to moderate severity were the most common diagnoses. No injuries to the pinna occurred probably because ear protectors were worn. Nine- to 14-year-old boys were injured least frequently (3.8%), partly because their matches were the shortest. The overall injury rate for high school and college wrestlers was 12.0%. Risk of injury did not vary with weight class or with successive matches. Thirty-nine percent of all injuries were because of aggravation of old injuries. Thus, rehabilitation after injury is believed to be an important preventive measure. These findings suggest that, although most injuries in wrestling are not severe, attendance at tournaments by medically trained personnel is warranted.

Reye's syndrome and medication use.

Ninety-seven Reye's syndrome (RS) cases in Ohio children with onsets from December 1978 through March 1980 were studied for medication use during their pre-RS illness. They were matched with 156 control subjects for age, race, sex, geographic location, time, and type of illness. Only the use of aspirin was reported by significantly more cases (97%, 94/97) than controls (71%, 110/156) during the pre-RS matched illness. Using a multiple logistic model to control for the presence of fever, headache, and sore throat statistically, the difference in aspirin use remained significant. Conversely, fewer cases (16%) took medications containing acetaminophen than controls (33%). In 87% of the cases receiving aspirin, their maximum daily dosage did not exceed recommended levels, but their doses were higher than those of controls receiving aspirin. No relationship was found between dosage and stage of RS encephalopathy.