[Survey on present status of noise exposure of workers in metal processing industry].

Objective: To investigate the distribution of noise exposure between non-steady state noise and steady-state noise for metal processing workers, which will provide scientific basis for the prevention and treatment of noise hazards in metal processing industry. Methods: The cross-section method was used to investigate the noise exposure of 737 workers from three metal processing industries in Zhejiang Province from October to December 2017. The general demographic information and occupational history were collected by questionnaire. The noise was recorded by individual noise meters, and the noise exposure intensity (equivalent continuous A-weighted noise exposure level normalized to an 8 h-working-day, L(Aeq, 8 h)) and kurtosis were calculated. Results: Workers exposed to noise in the metal processing industry were mainly 18-40 years old (527 workers, 71.51%) , men (570 workers, 77.34%) , and junior high school education background (416 workers, 56.45%) . There were 572 workers (77.61%) with noise exposure intensity (L(Aeq, 8 h)) greater than 85 dB (A) , 558 workers (75.71%) exposed to non-steady state noise (kurtosis ≥4) , and 634 workers (86.02%) with exposure duration less than 8 years. Among the 30 work types investigated, the work types with noise intensity reaching 100% were the stamping, welding and others from a children's car manufacturing factory in Ningbo, operating, chamfering, tapping, and thread rolling from an automobile parts manufacturing factory in Ningbo; The work types with a rate of 100% exposed to non-steady state noise were the grinding from a children's car manufacturing factory in Ningbo, assembling, assembly operating and others from an automobile brake manufacturing factory in Wenzhou, and polishing from an automobile parts manufacturing factory in Ningbo. Conclusion: Metal processing workers have a high rate of over-standard exposed to high noise intensity and a high proportion exposed to non-steady state noise. It is necessary to take sound insulation and noise reduction engineering control, and strengthen personal protection and occupational health management measures to prevent and control the noise hazards.

NaYbF4 nanoparticles as near infrared light excited inorganic photosensitizers for deep penetration in photodynamic therapy.

Photodynamic therapy (PDT) is a non-invasive therapy with many advantages over other therapeutic methods, but it is restricted to treat superficial cancers due to the shallow tissue penetration of visible light. The biological window in the near infrared region (NIR) offers hope to extend the penetration depth, but there is no natural NIR excited photosensitizer. Here, we report a novel photosensitizer: NaYbF4 nanoparticles (NPs). By using a 1,3-diphenylisobenzofuran (DPBF) sensor, we show that the Yb3+ ions can absorb the NIR light and transfer energy directly to oxygen to generate reactive oxygen species (ROS). The efficiency of transferring energy to oxygen by NaYbF4 NPs is comparable to that of traditional photosensitizers. We have carried out PDT both in vitro and in vivo based on NaYbF4 NPs; the results demonstrate that NaYbF4 NPs are indeed an effective NIR photosensitizer, which can help extend the application of PDT to solid tumors owing to the much deeper penetration depth of NIR light.

Positive association between PPARD rs2016520 polymorphism and coronary heart disease in a Han Chinese population.

PPARD encodes peroxisome proliferator-activated re-ceptor delta, which has been shown to play an important role in control-ling lipid metabolism and atherosclerosis. In this case-control study, we explored the relationship between PPARD rs2016520 polymorphism and coronary heart disease (CHD) in a Han Chinese population. A to-tal of 657 CHD cases and 640 controls were included in the associa-tion study. rs2016520 polymorphism genotyping was performed using the melting temperature-shift polymerase chain reaction method. The PPARD rs2016520-G allele reduced CHD risk by 17.9% (χ(2) = 5.061, P = 0.025, OR = 0.821, 95%CI = 0.692-0.975). Furthermore, a signifi-cant difference in CHD risk was observed for the PPARD rs2016520 polymorphism in the dominant model (AG + GG vs AA: χ(2) = 4.751, degrees of freedom (df) = 1, P = 0.029, OR = 0.784, 95%CI = 0.631- 0.976). Analysis by age suggested that the G-allele decreased CHD risk by 14.8% in ages greater than 65 years (χ(2) = 4.446, P = 0.035, OR = 0.852, 95%CI = 0.684-1.060). In contrast, meta-analysis of PPARD rs2016520 among 3732 cases and 5042 controls revealed no associa-tion between PPARD rs2016520 and CHD (P = 0.19). We found that the PPARD rs2016520-GG genotype decreased CHD risk in a Han Chinese population. Moreover, we found an association between serum high-density lipoprotein cholesterol level and PPARD rs2016520 in senior individuals aged ≥ 65 years. The meta-analysis revealed no association between PPARD rs2016520 and CHD, suggesting ethnic differences in the association between the PPARD locus and CHD.

Oral cancer: role of the basement membrane in invasion.

Invasive growth of cancer cells is a complex process involving specific interactions between tumour cells and the orderly, integrated complexes of the extracellular matrix. Basement membranes have been proposed as one constituent of extracellular matrix which carries responsibility for regulating invasion and metastasis. Using a chemically induced rat tongue carcinoma model, it has been shown that components of the basement membrane and its overall structure are altered during tumour invasion, and methods have been developed to quantitate some of these differences. Since the basement membrane can be specifically characterized by its fibrous protein network of Type IV collagen and laminin, which is embedded in a heparan sulphate-rich proteoglycan matrix, these components have been targeted. In particular, the current paper presents results in the context of current concepts of early changes in neoplastic invasion of underlying connective tissues. In consequence, further elaboration of the underlying mechanisms of epithelial migration in oral cancer may allow an exploration of the use of alterations in expression of basement membrane components as prognostic indicators.

Surgical treatment of solid brain stem tumors in adults: a report of 22 cases.

BACKGROUND: Brain stem tumors in adults are infrequent. Most reports of surgical treatment for these tumors involve partial tumor removal in highly selected patients. A more aggressive approach for removing tumors, especially solid and intrinsic ones, has been controversial. METHODS: Twenty-two adult patients with brain stem tumors were surgically treated. Surgical techniques, potential risks, and selection of appropriate treatment were evaluated. RESULTS: Tumors were totally or subtotally removed in 20 patients and only partially removed in two patients. Serious complications such as respiratory disturbances and circulatory dysfunction occurred in 10 patients. Eight patients with these complications recovered after appropriate treatments. Upon discharge, most signs and symptoms improved in 17 patients. CONCLUSION: Most brain stem tumors, except for malignant gliomas and small ventral tumors, are amenable to an aggressive surgical approach. Exophytic medullary tumors that present dorsally comprise the most benign subgroup of brain stem tumors. Total removal can enhance survival, improve the patient's quality of life, and offer a favorable long-term prognosis. Appropriate management of postoperative complications is essential for good results.

Reverse smoking and palatal mucosal changes in Filipino women. Epidemiological features.

The habit of reverse smoking is practised in various parts of the world including the Philippines. In this pilot, community-based, cross-sectional study carried out in the region of Cabanatuan City in the Philippines. 61 Filipina reverse smokers and 30 Filipina conventional smokers were interviewed and clinically examined. Seven demographic variables and twelve habit variables were compared in the two study groups. The majority (96.7 per cent) of reverse smokers exhibited palatal mucosal changes including leukoplakia, mucosal thickening, fissuring, pigmentation, nodularity, erythema and ulceration. In comparison, only 26.7 per cent of conventional smokers exhibited mucosal changes predominantly focal pigmentation and mild erythema. This difference was statistically significant at a X2 value of 47.28 (p < .001). Analysis of the other variables indicated that the two study groups differed significantly with regard to age (p < .05), educational attainment (p < .01), use of filtered versus non-filtered cigarettes (p < .001) and duration of smoking in years (p < .01).

Identification of basal lamina acidic glycoconjugates, particularly heparan sulphate proteoglycans, using a poly-L-lysine-gold probe in induced oral carcinomas.

Acidic glycoconjugates represent the major non-fibrous macromolecular components that form the extracellular and cell-associated matrices of all animal tissues. The constituent molecules are principally structural glycoproteins and proteoglycans. While their protein component is determined by gene pools, it is the polyanionic (acidic) nature of the polysaccharides, determined by their degrees of carboxylation and sulphation, which confers both functional and diagnostic status on these molecules. Sulphated glycoconjugates in the basal laminae have been reported to play a role in tumour invasion and metastasis. In this study, we used cationic colloidal gold together with transmission electron microscopic methods to compare the expression of acidic glyconconjugates in the basal lamina of both normal rat tongue mucosa and experimentally induced oral carcinomas. Results indicated that heparan sulphate rich glycoconjugates were predominant and were mostly confined to the lamina lucida of the basal lamina in normal oral mucosa. Conversely, observation of basal laminae associated with induced carcinomas showed less intense and more widely dispersed gold labelling for heparan sulphate. The observed differences in gold labelling may reflect modified metabolism of sulphated glycoconjugates or result from the action of degradative enzymes in the induced tumours.

Distribution of basal lamina type IV collagen and laminin in normal rat tongue mucosa and experimental oral carcinoma: ultrastructural immunolocalization and immunogold quantitation.

The relationship of basal lamina, a form of specialised extracellular matrix which separates epithelial cells and other cell types from adjacent stroma, to the behaviour of malignant neoplasms of epithelial origin is not well understood. However, it is widely acknowledged that the properties of local invasion and metastasis of carcinomas are linked to extracellular matrix (including basal lamina) changes. In the present study, the distribution of the major basal lamina components, type IV collagen and laminin, in normal rat tongue mucosa and experimentally induced oral carcinomas was investigated using post-embedding immunogold techniques and electron microscopy. The expression of these components was also quantitatively analysed using morphometry and immunocytochemistry. Results indicated that type IV collagen and laminin were confined to the lamina densa of normal oral epithelial basal lamina, and that both components were also detected in the lamina densa of basal lamina associated with carcinomas, and in the extracellular matrix of tumours. Furthermore, laminin was detected within stromal fibroblasts in normal tissues and experimental carcinomas. Quantitative analysis indicated that expression of laminin was significantly increased in carcinomas. In contrast, type IV collagen expression was significantly decreased. The quantitative changes observed in the two basal lamina constituents may be related to the process of tumour invasion, reflecting altered metabolic activities of tumour and stromal cells. These observations may be of use in understanding the architectural characteristics of oral mucosa basal lamina and in assessing the malignant potential of epithelial dysplasias or "premalignant" lesions.

Cerebral artery reconstruction in the treatment of large and giant intracranial aneurysms.

From 1978 to 1988, 14 giant intracranial aneurysms (more than 2.4 cm in diameter) and one large aneurysm (1.5 cm in diameter) were treated by extracranial/intracranial (EC/IC) bypass or cerebral artery reconstruction. Of the aneurysms, 10 were located at the intracavernous carotid artery (CCA). One of the 10 aneurysms was posttraumatic and located at both the carotid-ophthalmic artery segment and the bifurcation of the internal carotid artery (ICA). Three were seen at the middle cerebral artery (MCA) trunk. The aneurysms were demonstrated by angiography and CT scanning. They were treated with trapping of the aneurysm and superficial temporal artery (STA)/middle cerebral artery (STA-MCA) bypass with/without a graft (6 cases), cervical ICA ligation and STA-MCA bypass with/without a graft (6) aneurysm excision with an end-to-end anastomosis of the MCA and a STA-MCA bypass with a graft (1), proximal MCA occlusion and STA-MCA bypass with a graft (1), and aneurysm neck clipping following a STA-MCA bypass with a graft (1). The patients showed marked improvement after operation except one whose neurological deficit was aggravated temporarily. Postoperative angiography revealed that the anastomoses were patent in all cases. No surgical mortality or any delayed ischemic complications were noted after follow-up for 5.6 years. We believe that cerebral artery reconstruction or EC/IC bypass is still effective in the treatment of large and giant intracranial aneurysms.

Laminin and type IV collagen in experimental rat oral carcinomas.

The pattern of staining and the distribution of laminin and type IV collagen in normal rat tongue mucosa and induced tongue carcinomas were investigated by immunohistochemical techniques. Both normal and neoplastic epithelial basement membrane revealed positive staining for laminin and type IV collagen. However, compared with normal tissue, carcinomas exhibited areas of increased density and thickness for laminin. Focal tumour basement membrane discontinuities were observed in some specimens stained for type IV collagen.

Ultrastructural features of normal epithelium and 4-nitroquinoline 1-oxide-induced carcinomas of the rat tongue.

An electron microscopical examination of normal rat lingual mucosa and 4-nitroquinoline 1-oxide (4NQO)-induced tongue carcinomas was undertaken. In normal rat tongue, the epithelium of papillae and interpapillary regions exhibited two distinct keratohyalin granule types and essentially similar ultrastructural cellular features in the different epithelial compartments. The interface between epithelium and connective tissue showed a continuous basal lamina. Compared with normal rat tongue epithelium, 4NQO-induced oral carcinomas revealed cellular and nuclear pleomorphism, atypical tonofilament aggregates, increased and swollen mitochondria, dilated intercellular spaces, local discontinuities and thickening of the basal lamina.

[Inhibitory effects of clonidine on edema formation after thermal injury in mice and rats].

Clonidine 1 mg/kg ip given before thermal injury significantly inhibited the edema formation in mice and rats during the early stage of burn. Clonidine 0.1 mg/kg ip gave no such effect, but it became effective after being administrated via icv. The inhibitory effects of clonidine on edema formation were abolished by pretreatment with yohimbine 5 mg/kg ip, but not with prazosin 10 mg/kg ip. The tracing by 113mIn labelled transferrin demonstrated that clonidine decreased the capillary permeability in burned tissues 1 h after burn. When clonidine 1 mg/kg was given ip to the rats 20 min before burn, it lowered the level of lipoperoxide in the serum 2 h after burn. These results suggest that the inhibitory effects of clonidine on edema formation is most probably due to the depression of sympathetic activity via alpha 2 receptor during thermal injury.

Surgical treatment of 224 cases of big acoustic neurinoma with special consideration on 76 cases treated microsurgically.

Two hundred and twenty four cases of acoustic neurinoma, bigger than 4 cm in diameter were operated by suboccipital approach in the past 30 years. Among them, 148 cases were operated before the year of 1978 with conventional microsurgical technic, and 76 cases were operated since 1979 with microsurgical technic. In the former group of cases, the percentage of total removal of tumor was 83.8% and the mortality rate was 5.4%. In the latter group, all tumors were totally removed, there was no mortality, the facial nerve was preserved anatomically in 86.8% of cases and functionally in 71.1%, and the cochlear function was preserved in 21.1% of cases. In 5 cases, the severed ends of the facial nerve were anastomosed intracranially. All of them had their facial nerve function recovered. The historicals of surgery of acoustic neurinoma in China are reviewed. The operative technic used by the author is presented briefly. The factors influencing the preservation of the facial nerve are discussed.