Role of the industrial hygienist. Evaluation and management of occupational skin disease

The industrial hygienist provides an important resource for the prevention of occupational skin disease and injury. This is accomplished by the anticipation, recognition, evaluation, and control of dermal hazards in the workplace. The industrial hygienist can assess and control dermal hazards before the occurrence of injury or disease. For instances in which injury has occurred, the industrial hygienist can assist the physician in determining the cause as well as developing and implementing controls to reduce or eliminate the problem.     

Effect of lactic acid and proteolytic enzymes on the release of organic matrix components from human root dentin

The mechanisms of organic matrix breakdown in the root caries process are not well understood. Therefore, the combined and separate effects of lactic acid and proteolytic enzymes on the degradation of human dentin collagen, glycoproteins, proteoglycans and phosphoproteins were investigated in the present study. Dentin powder was pretreated with lactic acid (pH 4.0), distilled and deionized (dd) water (pH 7.0) and EDTA/guanidine HCl (pH 7.4) for 24 h. Pellets of acid- or dd water-pretreated dentin powder were washed, dried, and then treated with trypsin, bacterial or mammalian tissue collagenase, or control buffer for 3 h. The released dentin proteins were analyzed by reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting to identify degraded type I collagen, proteoglycans, glycoproteins and phosphoproteins. All water and acid pretreatment and enzyme treatment groups demonstrated two collagen fragment bands with molecular weights at approximately 79 kD. Further studies showed that the 79 kD proteins from acid-pretreated dentin collagen were degraded by tissue collagenase, suggesting that endogenous collagenase may be involved in the degradation of root dentin collagen. Dentin proteoglycans were detectable in all the treatment groups by protein slot blotting. Relatively few distinct glycoproteins and proteoglycans, and no phosphoproteins were detected by immunoblotting. Results from this study suggest that both acids and proteolytic enzymes from either host or microbial origin are important in the degradation of human dentin matrix and the mechanisms involved in the release of various noncollagenous proteins may be different.     

Wing scale microstructures and nanostructures in butterflies − natural photonic crystals

The aim of our study was to investigate the correlation between structural colour and scale morphology in butterflies. Detailed correlations between blue colour and structure were investigated in three lycaenid subfamilies, which represent a monophylum in the butterfly family Lycaenidae (Lepidoptera): the Coppers (Lycaeninae), the Hairstreaks (Theclinae) and the Blues (Polyommatinae). Complex investigations such as spectral measurements and characterization by means of light microscopy, scanning electron microscopy and transmission electron microscopy enabled us to demonstrate that: (i) a wide array of nanostructures generate blue colours; (ii) monophyletic groups use qualitatively similar structures; and (iii) the hue of the blue colour is characteristic for the microstructure and nanostructure of the body of the scales.     

Headache and cortisol responses to m-chlorophenylpiperazine are highly correlated

The serotonin receptor agonist m-chlorophenylpiperazine (m-CPP) stimulates the release of cortisol and prolactin, and induces migraine-like headaches. We have studied the neuroendocrine and headache responses to m-CPP in 8 subjects with migraine and 10 normal subjects. Each subject underwent two challenge tests, one with 0.25 mg/kg PO of m-CPP and the other with placebo, administered in a double-blind crossover format. Serial measurements of serum cortisol, prolactin, and m-CPP levels were made at 30-min intervals for 210 min following ingestion of the medication. The incidence and severity of headache was assessed by a structured telephone interview after each test. We confirmed that m-CPP stimulates the release of cortisol and prolactin, and may induce headache, in both migraine subjects and normal controls. The cortisol response as well as ratings of headache severity and duration directly correlated with plasma levels of m-CPP. There were highly significant associations between the cortisol response and both headache severity and duration, independent of m-CPP plasma levels. We did not find statistically significant differences between the migraine and normal subjects in terms of their neuroendocrine or headache responses to m-CPP.     

Carbamazepine responsive epileptic oral motor and ocular motor apraxia

We evaluated seven patients with oral motor apraxia and ocular motor apraxia. Apraxia in three patients (Group 1) with new-onset partial seizures and epileptiform discharges on EEG improved with carbamazepine. Four patients (Group 2) without seizures and nonepileptiform EEG findings had no change in apraxia after a trial of carbamazepine. Epileptic apraxia may precede clinical seizures and can respond to antiepileptic drugs.     

Hydroxyphthalocyanines as potential photodynamic agents for cancer therapy

A series of benzyl-substituted phthalonitriles, substituted at the 3-, 4-, and 4,5-positions, underwent varied condensations with phthalonitrile to give a series of protected (monohydroxy- and polyhydroxyphthalocyaninato)zinc(II) derivatives which were readily cleaved to give several hydroxyphthalocyanines (ZnPc) (phthalocyanine phenol analogues). Their efficacy as sensitizers for the photodynamic therapy (PDT) of cancer was evaluated on the EMT-6 mammary tumor cell line. In vitro, the 2-hydroxy ZnPc (32) was the most active, followed by the 2,3- and 2,9-dihydroxy ZnPc (39 and 45), with the 2,9,16-trihydroxy ZnPc (33) exhibiting the least activity. In vivo, the monohydroxy derivative 32 and the 2,3-dihydroxy derivative 39 were both efficient in inducing tumor necrosis at 1 micromol kg-1, but complete tumor regression was poor, even at 2 micromol/kg. In contrast, the 2,9-dihydroxy isomer 45, at 2 micromol kg-1, induced tumor necrosis in all animals treated, with 75% complete regression. These results underline the importance of the position of the substituents on the Pc macrocycle to optimize tumor response and confirm the PDT potential of the unsymmetrical Pcs bearing functional groups on adjacent benzene rings.     

An experimental study of the interleukin 1 levels in aqueous humor after intraocular lens implantation

Identification of unknown bodies is mainly made by dental examination and comparison with accurate dental records. Therefore it is necessary to examine the jaws carefully and to locate every tooth-coloured dental restoration. Overlooking dental fillings can make positive identification impossible. The technique described prepares the natural dental hard tissue by etching with 37% phosphoric acid. In the next step an indicator colours the roughened dental tissue but not the polished restoration material. In this way all 15 tested dental restoration materials could be detected with high sensitivity.     

Palmar fracture dislocation of the proximal interphalangeal joint

Palmar fracture dislocation of the proximal interphalangeal joint is uncommon. Thirteen patients treated for this injury were retrospectively reviewed. There were 9 acute injuries. Seven were treated by closed reduction and percutaneous pin fixation and 2 were treated by open reduction and internal fixation. The 4 chronic injuries (more than 1 month after injury) were treated with open reduction and soft tissue reconstruction. The length of follow-up averaged 55 months. Eight patients were free from pain. Postoperative proximal interphalangeal motion averaged 91 for the acute injuries and 70 degrees for the chronic injuries. Follow-up radiographic findings were notable for an increased height of the middle phalangeal base in 6 patients, articular irregularity in 4, and residual subluxation in 2; however, these changes did not correlate with the clinical results. Complications included loss of reduction in 1 patient, progressive swan neck deformity in 1, and development of an average 25 degrees extension lag of the distal interphalangeal joint in 5.