Particulate matters collected from ceramic factories in Lampang Province affecting rat lungs.

BACKGROUND: Lung cancer ranks as the fifth largest of all cancer cases in Thailand. However, it is the first leading cancer in the northern part of Thailand (data from 2003-2007). There are several predisposing causes that lead to lung cancer and one important inducement is particulate matters (PMs). Lampang Province in Thailand is famous for the ceramic industry, where there are over 200 ceramic industrial factories. PMs are produced during the ceramic manufacturing process and spread throughout all of the working areas. It is very possible that workers could directly inhale PM-contaminated air during working hours. OBJECTIVE: This study focuses on the toxic effects of PMs collected from ceramic factories on genes and lungs of rats. METHODS: PMs collected from six ceramic factories in Lampang Province were extracted using dimethyl sulfoxide (DMSO). The inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES) were used to analyze the chemical elements at lower and higher concentrations, respectively. Then, the toxicity of PMs on the genes was examined by the Ames test, and subsequently, the effect of PMs on DNA was examined by quantifying the amount of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Finally, the toxicity of the PMs on rat's lungs was examined by histology. RESULTS: As chemical elements of lower concentrations, cadmium, chromium, nickel, copper, and lead were detected by ICP-MS. As chemical elements of higher concentrations, manganese, magnesium, zinc, iron, potassium, calcium, and sodium were detected by ICP-OES. No mutagenicity in Salmonella typhimurium was found in the PM extracts from all six factories by utilizing the Ames test. In the histological study, the reduction in spaces of alveolar ducts and sacs, and terminal bronchioles, the thickening of interstitial connective tissues were noted by PM extracts in high amounts (100 and 350 µg). Female rats were more sensitive to PM extracts than males in terms of their pulmonary damages. CONCLUSIONS: PMs were not mutagenic to S. typhimurium but can damage the lung tissue of rats.

Evaluation of non-viral risk factors for nasopharyngeal carcinoma in Thailand: results from a case-control study.

Nasopharyngeal cancer (NPC) is rare in most populations but common in Southern China and Southeast Asia. To understand the role of environmental exposures on risk of NPC, a case-control study was conducted among 327 newly diagnosed case of NPC and 327 controls matched to case on sex, age and geographic residence. Information was collected by interviewer about demographic variables, cigarette smoking, alcohol drinking, eating habits, past history of disease, family history of cancer and a lifetime history of every job that was held for one year or longer. The result indicates that cigarette smoking was associated with an increased risk of NPC (OR=2.41, 95% CI 1.61-3.6). There was indication of increased risk with a history chronic ear or nose disease (OR=2.71, 95% CI 1.45-5.06). Occupational exposure to wood dust was also associated with a higher risk (OR=1.63, 95% CI 1.02-2.61). Furthermore, lower education was found to be positively associated with NPC (OR=2.71, 95% CI 1.45-5.06). There was no association between NPC and salted fish intake (OR=1.38, 95% CI 0.84-2.25) or alcohol consumption (OR=0.88, 95% CI 0.58-1.33). Our results suggest that cigarette smoking, past history of ear or nose disease and occupational exposure to wood dust may play a role in the development of NPC in the Thai population.

Effect of bitter melon (Momordica charantia Linn) on level and function of natural killer cells in cervical cancer patients with radiotherapy.

Cervical cancer patients have a defective immune system. There is a decrease of total white blood cell count including lymphocytes and natural killer (NK) cells. NK cells, one type of lymphocytes, play a role to eliminate cancer cells by antibody dependent cell mediated cytotoxicity (ADCC) mechanism. Previous studies have shown that P-glycoprotein (170 kDa, transmembrane protein) may be a transporter for cytokine releasing in ADCC mechanism. This study proposed to explore the role of bitter melon intake in cervical cancer patients undergoing normal treatment (radiotherapy). Subjects were divided into three groups: 1) normal control (women 35-55 years, n = 35), 2) patient control (n = 30) and 3) patient treatment (n = 30) groups. Patient control and patient treatment groups were cervical cancer patients (stage II or III) treated with radiotherapy (without or with bitter melon ingestion). Blood samples of patient control and patient treatment groups were analyzed for NK cells percentage and P-glycoprotein level. Bitter melon is a Thai herb. Previous studies have shown that bitter melon can stimulate lymphocyte activity in vitro and in vivo (mouse). The authors hope that bitter melon could stimulate the increase of NK cells percentage and P-glycoprotein level on the membrane in blood samples from cervical cancer patients who ingest bitter melon. The results showed an increased percentage of NK cells in patient control and patient treatment groups. The increase in each group is significant (p < 0.05) when compared with the percentage of NK cells from second and third blood sampling time (after radiation with of without bitter melon intake for 45 and 90 days) with first blood sampling time (before treatment). The results also show a significant decrease of P-glycoprotein level (p < 0.05) in second and third blood sampling times when compared with first blood sampling time of the patient treatment group. There was no significant difference of P-glycoprotein (P-gp) level from first, second and third blood sampling times in patient control group. Bitter melon ingestion did not affect NK cell level but it affected the decrease of P-gp level on NK cell membrane.