Vascular endothelial growth factor response with propranolol therapy in patients with infantile hemangioma.

Vascular endothelial growth factor-A (VEGF-A) is a master regulator of angiogenesis, with higher levels in infantile hemangioma (IH). The effects of propranolol on IH are not fully understood and may involve vasoconstriction, angiogenesis inhibition, and apoptosis induction. Therefore, we examined the effects of propranolol therapy on levels of VEGF-A in patients with IH in the proliferative phase and compared the VEGF-A levels to those in untreated patients in the involuting or involuted phases, as well as studied the consistency between the clinical and VEGF responses in patients receiving treatment. In a prospective study, we compared 24 patients with IH in the proliferative phase to 9 patients with IH in the involuting or involuted phase, assessing clinical responses to therapy and changes in VEGF-A levels after 3 months. The median VEGF level before treatment was 275 pg/ml; however, after 3 months, the level significantly decreased to 100 pg/ml (P = 0.007). Median VEGF was significantly higher in patients in the proliferative phase after 3 months of treatment (100 pg/ml) as compared to those in the involuting phase (50 pg/ml). We found no significant correlation between VEGF level and IH size reduction. Propranolol therapy induced a significant decline in VEGF levels at the 3-month evaluation in patients in the proliferative phase; however, this did not reach the levels of IH in the involuting phase. VEGF response was not translated to a clinical response in some patients with IH. These results put in uncertainty the clinical benefit of targeting VEGF pathway in IH.

Broken orthodontic trans-palatal archwire stuck to the throat of orthodontic patient: is it strange?

Trans-palatal arch wire is in common use in orthodontic practice. This case report of broken trans-palatal wire, swallowed and stuck to the throat of an orthodontic patient, is presented in the hope that it will stress the importance of careful examination of the appliance at each scheduled visit.

The potential of digital dental radiography in recording the adductor sesamoid and the MP3 stages.

The current study was undertaken to evaluate the reliability of using a recent advance in clinical radiographic technique, digital dental radiography, in recording two growth indicators: the adductor sesamoid and MP3 stages. With an exposure time five times less than that used in the conventional approach, this method shows greatest flexibility in providing a high quality digitized radiographic images of the two growth indicators under investigation. Refereed Paper

The reliability of dental x-ray film in assessment of MP3 stages of the pubertal growth spurt.

The main object of this clinical study is to provide a simple and practical method to assess the pubertal growth spurt stages of a subject by recording MP3 stages with the dental periapical radiograph and the standard dental x-ray machine.

Exposure-related declines in the lung function of cotton textile workers. Relationship to current workplace standards.

To evaluate the effectiveness of the current workplace standards in preventing chronic health effects from cotton dust exposure, a 5-yr longitudinal study of a large multimill population of cotton textile and synthetic process workers, employed at a major U.S. textile company, was conducted. To control for and assess the effect of type of work area on annual change in lung function, we limited the analysis to those 1,817 subjects who, throughout their textile work history at the company, worked exclusively in cotton yarn manufacturing or slashing and weaving, or in synthetic textile mills. The expected effect of smoking on average annual change in lung function was demonstrated for both cotton and synthetic workers. Despite lower overall dust exposure, cotton yarn workers exhibited steeper annual declines in lung function than did workers in slashing and weaving; this difference persisted within each smoking category, indicating a dust potency effect. There were mill differences in annual change in lung function among cotton workers, potentially masking an exposure effect. A smoking-work area interaction persisted after adjusting for mill differences, with the largest annual declines observed in cotton yarn workers who smoke. A significant dose-response relationship was seen in cotton yarn manufacturing between annual declines in FEV1, FVC, and FEF25-75 and average exposure by mill, and the larger declines were found in mills using the highest percentage and lowest grade of cotton. Synthetic textile workers had larger declines than did cotton textile workers, which were not explained by smoking or duration of employment. Unrecognized and unmeasured causative exposures or selection bias could explain this result.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term cotton dust exposure in the textile industry.

A three-year survey was conducted in six cotton-yarn manufacturing mills and one mill processing synthetic polyester fibers as part of a longitudinal epidemiologic investigation of the health experience of workers employed in the textile industry. A total of 1324 elutriated and total dust samples were collected during the three years of the study. The results indicate that the average elutriated dust concentrations in the surveyed mills were generally at or below the current OSHA standard and they ranged from 0.069 to 0.396 mg/m3, 0.089 to 0.391 mg/m3, and 0.106 to 0.210 mg/m3 for the first, second and third year surveys, respectively. Introduction of modern automated yarn processing equipment and elimination of some of the classic processes were associated with a decreasing trend in airborne dust concentrations in these mills.

Clinical crown length and reduction in overjet, overbite, and dental height with orthodontic treatment.

To evaluate the clinical crown length relative to fixed-appliance orthodontic treatment of excessive overjet and deep overbite and to correlate such changes to the vertical dental height, the following measurements were undertaken for 12 females and 8 males, between the ages of 16 and 20 years, on three separate occasions--2 days before banding, 2 days after debanding, and 12 months after debanding: (1) overjet, overbite and dental height measured from right lateral cephalometric x-ray films; (2) clinical crown length, measured from study models, of 400 teeth divided into four groups--maxillary incisors and canines (120 teeth), maxillary second premolars and first molars (80 teeth), mandibular incisors and canines (120 teeth) and mandibular second premolars and first molars (80 teeth); and (3) gingival condition by means of the gingival index of Löe and Silness. Fixed edgewise orthodontic appliances were used and the four first premolars were extracted. From the results of the investigation, the following conclusions were evident: after a 12-month follow-up observation period, the achieved reduction in overjet, overbite, and dental height showed relapses of 9%, 11%, and 29%, successively; only 7% of the 400 teeth examined showed reductions in clinical crown length. This change was probably the result of gingival hyperplasia. The gingival condition greatly improved by approximately 64% after 12 months of debanding, accompanied by 25% to 50% relapse in the amount of change in clinical crown length (noted 2 days after debanding); and the intrusive tooth movement during orthodontic correction of deep overbite was the result of vertical movement of the tooth, with its investing tissues and soft-tissue attachment, into the jaws.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of histamine in the aetiology of byssinosis. II. Lung histamine concentrations in guinea pigs chronically exposed to cotton and flax dusts.

Data presented in this study support the finding that cotton and flax dusts contain agents which potentiate the formation or accumulation of histamine or both in the lungs of guinea pigs exposed to dust, and that such agents are present at much higher levels in cotton dust than in flax dust. The potentiating effect may be through the recruitment of mast cells into the lung. Both cotton and flax dusts contain methylating enzyme inhibitory agents, whereas cotton dust also contains agents that inhibit histaminase activity; flax dust contains agents potentiating histamine activity. These agents working together result in the accumulation or depletion of histamine observed in the different groups of animals exposed to either cotton or flax dust in this study.

Role of histamine in the aetiology of byssinosis. I Blood histamine concentrations in workers exposed to cotton and flax dusts.

The formation or the accumulation, or both, of histamine in the lungs may be potentiated by agent(s) present in cotton dust at higher level(s) than in flax dust and negligible in cottonseed dust. It has been suggested that such potentiation may be due to the activation of the ability of the lung to produce histamine and/or produce or recruit mast cells; this may present an acceptable explanation of the mechanism by which the propagation of the chronic effect of the dust proceeds in cotton and flax workers. Histamine accumulated in the lung over the weekend is released on exposure to dust causing the symptoms of byssinosis. The difference in the rate of histamine metabolism relative to the rate of histamine formation in byssinotic subjects leads to a more prolonged histamine accumulation than in symptom free subjects, with the consequent appearance of the symptoms of byssinosis. Continuous exposure to dust, without weekend interruption, leads to equivalent rates of histamine formation and metabolism with non-considerable histamine accumulation in the lungs and consequent absence of the symptoms of byssinosis.

Isomeric composition of airborne TDI in the polyurethane foam industry.

The isomeric composition of airborne toluene diisocyanate has been determined in two plants producing slab stock flexible polyurethane foam. The high performance liquid chromatographic technique used for analysis of the collected samples was optimized for the quantitative and qualitative determination of 2,4 and 2,6-TDI. The data indicates that there is a very large increase in the amount of airborne 2,6-TDI relative to the 2,4 isomer, as compared to the starting material used in the process. The magnitude of the increase was dependent on the stage of production. These results are consistent with the hypothesis of increased offgassing of 2,6-TDI, due to its lower reactivity.

Vertical lip height and dental height changes in relation to the reduction of overjet and overbite in Class II, Division 1 malocclusion.

Changes in vertical lip height in relation to dental height, overjet, and overbite of orthodontically treated Class II, Division 1 malocclusions are evaluated through cephalometric roentgenograms of twenty-two male patients. Treatment entailed extraction of the four first premolars and use of the edgewise technique. The results are statistically analyzed, and correlations between various binary combinations are subjected to the 1 percent confidence limit. On the basis of this study, it is concluded that (1) the reduction of overjet, overbite, and dental height with orthodontic treatment is statistically significant at the 1 percent level; (2) the reduction of overjet to that of overbite shows a mean ratio of 1.83 to 1. On the other hand, a reduction of 1 mm, in dental height is accompanied by an average reduction of 3.98 mm. in overjet and of 2.17 mm. in overbite; (3) there is also an insignificant increase in vertical lip height accompanied by a decrease in dental height. The relation is statistically insignificant, however.