Vascularity and expression of vascular endothelial growth factor in oral squamous cell carcinoma, resection margins, and nodal metastases.

The role of vascularity as a predictor of the likelihood of lymph node metastases in oral cancer is not clear. To that end, the vascularity and expression of vascular endothelial growth factor (VEGF) was assessed at three specific regions: the tumour (inside and around the tumour); the resection margin; and the regional lymph nodes. Formalin-fixed paraffin-embedded specimens from 26 oral cancers (11 with no involved nodes and 15 with involved nodes) were stained immunohistochemically and examined. Staining for VEFG was significantly greater in the tumour than in the other sites. No significant differences were found in the intensity of staining in the primary tumour, resection margins, or nodes between cases in which the nodes were involved and in which they were not involved. We found no correlation between vascularity and VEGF staining, suggesting that VEGF is not the primary or only stimulator of angiogenesis in oral cancer. Greater understanding of the mechanisms of metastasis will lead to new treatments. The evidence that is accumulating for oral cancer suggests that such treatments may be better targeted at preventing lymphatic spread, rather than vascular spread.

The effect of the antibody used and method of quantification on oral mucosal vascularity.

A vast literature exists on angiogenesis particularly with regard to understanding tumour growth and development. This is no less true for oral cancer, where slight variations in protocols may invalidate comparison between studies. The influence of tissue processing, and the specific antibody and method of quantification used to identify blood vessels was assessed with respect to oral mucosal vascularity. The angiogenic profile of 20 frozen sections of clinically normal oral mucosa were compared with 16 paraffin-embedded specimens. Eight of the frozen specimens had matched paraffin-embedded tissue. Vascular antigens were identified immunohistochemically using four antibodies and blood vessel density was measured by three methods. CD31 and von Willebrand's factor (vWF) counts were higher than alpha-smooth muscle actin and alphanubeta3. Results for CD31 were higher in frozen tissue than paraffin-embedded tissue. Significantly more CD31-positive vessels were found in frozen tissue in the cohort of matched samples. For paraffin-embedded tissue vWF gave higher values for vascularity than CD31. The variation in antibody reaction to these markers of blood vessels suggests that the antibody employed and method of fixation is more important than the method of quantification used. Comparison of the results for fresh frozen tissue and paraffin-processed tissue suggests that this is acceptable for vWF but not for CD31.

Evidence for a field change effect based on angiogenesis in the oral mucosa? A brief report.

The concept of field cancerisation was proposed to explain the development of second primary tumours in the upper aerodigestive tract. The formation of new blood vessels (angiogenesis) has been shown to accompany oral disease progression, however, little is known about its potential role as an indicator of field cancerisation. The aims of this study were to compare the angiogenic profile of normal oral mucosa from oral cancer patients with that sampled from cancer-free patients to seek evidence for differences that might be termed a field change. Oral mucosal tissue (NC) was obtained from 25 oral cancer patients from a site at least 1 cm distant from the primary tumour and was compared with normal oral mucosa (NN) from a further 20 non-cancer patients. The vascularity of the tissue was investigated immunohistochemically using four antibodies and three methods of quantitation. Vascularity was significantly higher in the NC group than the NN with all four markers (p<0.01). Significantly higher indices of vascularity were found for patients who were smoker/drinkers in the NC group (p<0.05). The increased vascularity may provide a rationale for anti-angiogenic drug therapy for tertiary prevention.

Autoantibodies to neurofilaments (NF), glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) in workers exposed to lead.

An expanded follow-up assessment of the autoantibody response to neuronal and astroglial autoantigens (NF68; NF160; NF200; MBP; GFAP) as early markers of neurotoxicity was performed in male workers exposed to lead (Pb) of a battery factory (n=50) and a matched reference group (R) of workers at a food packing plant (n=39). Mean age, years of exposure and blood lead (PbB ug/dl) (+/-SD) for lead and R, respectively, were: Age:39 +/- 6; 41 +/- 7; Yrs. Exposed: 14 +/- 6:0; PbB: 32 +/- 11: 16 +/- 5 percent with detectable titers to nervous system proteins in the Pb and R populations, respectively, were: Anti-NF68: 59; 17; Anti-NF160: 28; 15; Anti-NF200: 25; 0; Anti-GFAP: 90; 20; Anti-MBP: 16; 4. Autoantibodies to nervous system proteins predominated in workers occupationally exposed to Pb compared to R. Anti-NF68 and GFAP titers were the most frequently encountered. Anti-NF68 titers were significantly correlated with years of exposure (r = 0.538, p < 0.0001) and with PbB (r=0.325, p < 0.05). Furthermore, the number of detectable autoantibody types correlated with clinical scores of sensorimotor deficits (r = 0.459, p < 0.0001). This study suggests that autoantibodies provide a promising biomarker of neurotoxicity while providing information on subcellular targets. It also raises concerns of toxicant-induced autoimmune neuropathy.

Assessment of antisperm antibody in sera of mercury and lead exposed workers.

Occupational exposure to lead or mercury was found to make protein better antigens. The production of autoantibodies to nervous system protein is one example of such effect. The present study aims to detect the possibility of induction of antisperm autoantibodies due to occupational exposure to lead or mercury. Male workers exposed to lead (n = 50) or to mercury (n = 39) were selected for this purpose and compared to a matched control group (n = 39). A negative control consisting of 17 females was also included. All subjects had two or more children. Blood samples were collected and the ELISA technique was applied to detect antisperm antibodies. Also, the levels of lead in blood and mercury in urine were determined as biological indices of exposure. Antisperm antibodies were detected in 90% of workers exposed to lead with the predominance of the IgG type and 84.6% of workers exposed to mercury with the predominance of the IgM type. Although the results did not correlate with the biological indices of exposure, it seems advisable to use the detection of sperm antibodies of sera of workers exposed to metals as a biological monitoring tool.

Changes in some metalloenzymes and trace metals among workers occupationally exposed to lead in battery manufacture.

The present study was conducted aiming to evaluate the impact of lead [Pb] exposure on the activities of some metaloenzymes as TIBC, SOD, ALP and MAO and their related trace metals among workers. Ninety workers occupationally exposed to Pb in a battery manufacturing plant in Alexandria city were included in this study, 50 of them were the exposed group and 40 control subjects. The present study showed a statistically significant higher level of biological indices of exposure (p < 0.01) of lead in blood among the exposed group than the control subjects. Exposure to Pb led to decreased levels of Zn and Fe which was accompanied by increase in the level of TIBC and decrease in activity of ALP. However, no significant variation could be detected in the level of Cu and its metalloenzyme as SOD and MAO between exposed and control subjects.

Biological monitoring of occupational exposure to benzene and toluene.

This study was carried out to evaluate the biological monitoring of occupational exposure to benzene and toluene in a total number of 31 male exposed workers and 30 control subjects. The present study showed a statistically significant higher level of biological indices of exposure (p < 0.01) of phenol and hippuric acid in urine of workers exposed to benzene and toluene than control subjects. Significant changes (p < 0.05, 0.01) in the levels of hematological and biochemical findings have been observed among exposed workers and control group. In addition, statistically significant higher levels of Mg, Mn and Ca were found among workers exposed to benzene and toluene while statistically significant lower levels of serum iron (p < 0.05) have been observed. No significant variations could be detected in the level of Zn and Cu between exposed and control subjects.

Effect of occupational exposure to ammonia on enzymatic activities of catalase and mono amine oxidase.

The study was carried out to investigate the effect of ammonia inhalation on a total number of 60 male subjects from an urea production plant located in Alexandria. Laboratory investigations were carried out for 30 exposed and 30 controlled subjects. The results showed statistically significant inhibition (p<0.01) in the activity of catalase enzyme among the exposed than the control subjects. The inhibition could lead to deleterious effects on electrical stability, permeability and fluidity of membranes, which could affect the liver and brain to be more susceptible to hepatotoxic and neurotoxic alterations. The present work showed a significant inhibition (p<0.01) of monoamine oxidase (MAO) activities and significant increase (p<0.05, 0.01) in liver function activities among exposed subjects than the control subjects.

Biological monitoring of occupational exposure to contraceptive drugs.

The present study was carried out for screening some biochemical changes due to occupational exposure to contraceptive drugs. It included 18 male workers and 22 female workers involved in the manufacture of contraceptive pills and 34 female workers manufacturing contraceptive ampoules. The levels of some sex hormones and gonadotropins were evaluated. Some parameters of blood picture, blood coagulation, liver and kidney functions, lipid profile and trace elements metabolism were assessed. Results were compared with those of a control group composed of 19 males and 27 females. Increased levels of estrogen among exposed workers was the main finding. It has been attributed to liver rather than pituitary dysfunction. A less atherogenic lipid profile has also been found. Referral to preventive measures has been recommended.

Somatic cell mutation in workers occupationally exposed to mercury vapors.

Somatic cell mutation in human peripheral lymphocytes is one of the tools used recently in the biological monitoring of the work environment. The scope of this review was to test whether biomonitoring methods are sensitive to the presence of mercury (Hg) in the body. We used the following techniques: micronucleus frequency (MN), sister chromatid exchanges (SCE), and hypoxanthine guanine phosphoribosyl transferase (HGPRT) assay in human lymphocytes. A total number of 30 male workers exposed to Hg vapors in chloralkali industry had been selected and compared with 30 control subjects. The concentration of mercury in urine (HgU) was used as a biological index of exposure. The exposed group showed higher levels of MN (32.0 +/- 1.7), SCE (7.3 +/- 0.2),and HGPRT mutations (0.94 +/- 0.01) then the nonexposed controls. We recommend the introduction of somatic cell mutation analysis in the periodic medical examination of workers exposed to Hg vapors.

Study of some biochemical changes among workers occupationally exposed to phenol, alone or in combination with other organic solvents.

The present study was aimed for the effects of exposure to multiple organic solvent vapors in comparison with single exposure to phenol. It included 20 workers exposed to phenol alone and 32 workers of combined exposure to phenol, benzene, toluene and methyl ethyl ketone. A control group of 30 subjects was also included. The levels of transaminases, total proteins, prothrombin time, bleeding time, clotting time, fasting blood sugar, serum creatinine and some trace elements (copper, zinc, iron, magnesium, manganese and calcium) were determined in blood together with a complete blood picture. Urine samples were analyzed for phenol, hippuric acid and methyl ethyl ketone. The effects of combined exposure did not differ from that of exposure to phenol alone concerning the majority of the tested parameters. Only the levels of platelets count, prothrombin time, eosinophils, copper and iron have been affected by combined exposure in a probably additive manner.

Biological monitoring of occupational exposure to electrophilic compounds.

Electrophilic compounds are widely used in industry. Plastic and dyeing industries are foremost examples of sites where workers are exposed to electrophilic compounds. Besides their immediate effect on different body systems, electrophilic compounds include most mutagenic and carcinogenic substances. The present study was carried out to elucidate the possibility of using nonselective assays in the biological monitoring of occupational exposure to electrophilic compounds. The study included a total number of 225 workers selected from the Plastic and Battery Company where workers are exposed to styrene (n = 70), and the Kafr El Dawar chemical and Dyeing Company where workers are exposed to aniline (n = 60) and benzidine (n = 25). Workers exposed to diesel engine exhaust were selected from a bus garage in Smoha (n = 70). A comparison group consisting of 141 subjects was selected from the administrative departments of the selected factories. The biochemical tests carried out on each subject included: (1) estimation of the biological indices of exposure: urinary mandelic acid and benzidine, blood methemoglobin, and carboxyhemoglobin, (2) liver and kidney function tests; and (3) nonselective biochemical parameters of early detection of carcinogenic and mutagenic risk: urinary thioether levels, urinary RNase and alpha esterase activities. The study revealed that two out of three nonselective assays have been affected by occupational exposure to electrophilic compounds. These were the urinary thioethers and RNase levels. Their determination is recommended in the biological monitoring of workers exposed to such agents especially in developing countries.

Study of the lipoprotein pattern among workers exposed to lead.

Occupational exposure to lead fumes constitutes a serious problem in Egypt, since a considerable number of workers might be involved in its deleterious effect. The present study aimed to elucidate the effect of lead exposure on the lipoprotein pattern of exposed workers. The study has been carried out in a plant manufacturing lead batteries. It consists of 89 workers exposed to lead and 25 control subjects. Fasting blood samples were collected for the determination of serum lipoprotein pattern and their cholesterol and phospholipid content. Levels of lead in blood and delta amino levulinic acid in urine have been determined as biological indices of lead exposure. Lead exposure caused mainly a cumulative effect on the cholesterol and phospholipid content of lipoproteins since only workers exposed for more than 10 years showed significant changes. These changes might be referred to the effect of lead exposure on liver and/or on trace metal metabolism.