Removing arsenic from groundwater in Cambodia using high performance iron adsorbent.

In Cambodia, groundwater has been contaminated with arsenic, and purification of the water is an urgent issue. From 2010 to 2012, an international collaborative project between Japan and Cambodia for developing arsenic-removing technology from well water was conducted and supported by the foundation of New Energy and Industrial Technology Development Organization, Japan. Quality of well water was surveyed in Kandal, Prey Veng, and Kampong Cham Provinces, and a monitoring trial of the arsenic removal equipment using our patented amorphous iron (hydr)oxide adsorbent was performed. Of the 37 wells surveyed, arsenic concentration of 24 exceeded the Cambodian guideline value (50 µg L(-1)), and those of 27 exceeded the WHO guideline for drinking water (10 µg L(-1)). Levels of arsenic were extremely high in some wells (>1,000-6,000 µg L(-1)), suggesting that arsenic pollution of groundwater is serious in these areas. Based on the survey results, 16 arsenic removal equipments were installed in six schools, three temples, two health centers, four private houses, and one commune office. Over 10 months of monitoring, the average arsenic concentrations of the treated water were between 0 and 10 µg L(-1) at four locations, 10-50 µg L(-1) at eight locations, and >50 µg L(-1) at four locations. The arsenic removal rate ranged in 83.1-99.7%, with an average of 93.8%, indicating that the arsenic removal equipment greatly lower the risk of arsenic exposure to the residents. Results of the field trial showed that As concentration of the treated water could be reduced to <10 µg L(-1) by managing the As removal equipment properly, suggesting that the amorphous iron (hydr)oxide adsorbent has high adsorbing capacity for As not only in the laboratory environment but also in the field condition. This is one of the succeeding As removal techniques that could reduce As concentration of water below the WHO guideline value for As in situ.

Oral verruca vulgaris in a bone marrow transplant patient: a case report and review of literature.

Viral infections can cause severe morbidity in immunosuppressed cancer patients. A case of rapidly enlarging, biopsy-documented oral verruca vulgaris in a patient undergoing conditioning chemotherapy prior to bone marrow transplantation (BMT) is described. Human papillomavirus infections in immunosuppressed patients are discussed.

Helium-neon laser effects on conditioning-induced oral mucositis in bone marrow transplantation patients.

BACKGROUND: Oral mucositis is a common complication of bone marrow transplantation (BMT) conditioning therapy. Sequelae consist of increased risk for infection, moderate to severe pain, compromised oral function, and bleeding. This study investigated helium-neon laser treatment for prevention of conditioning-induced oral mucositis in BMT patients. Patterns and severity of mucositis for specific conditioning drug regimens also were analyzed. METHODS: Twenty patients received laser radiation to their oral mucosa, either left or right of midline. The contralateral side was sham-treated and served as a control. Mucositis severity was scored independently by two modified versions of the Oral Mucositis Index Scale (OMI-A and OMI-B) and the Eastern Cooperative Oncology Group (ECOG) Oral Toxicity Scale; pain severity was scored by subjects on a visual analogue scale (VAS). Cumulative scores were analyzed for differences between the laser-treated and sham-treated sides. RESULTS: Oral mucositis and pain scores were significantly lower for the treated versus the untreated side by OMI-A and B (P < 0.005) and VAS (P = 0.027) criteria, respectively. Ulcerative lesions occurred in all patients bilaterally; severity increased until Day +6, and lesions resolved by Day +21. Mucositis was more severe for patients conditioned with busulfan/carboplatin/thiotepa than for patients conditioned with busulfan/cyclophosphamide/etoposide. CONCLUSIONS: Helium-neon laser treatment was well-tolerated and reduced the severity of conditioning-induced oral mucositis in BMT patients.

Microvascular volumes in healthy and inflamed gingiva in humans.

It has been suggested that the vascular alterations found in inflamed gingiva may be of significance in the enhanced extension of the pathological process into the periodontium. The purpose of this investigation was to measured the changes in blood vascular volume occurring in gingiva with the onset of gingivitis and its resolution. Twenty-six individuals participated in this study. Gingival biopsies were taken following a 21-day experimental gingivitis, following resolution of a 21-d experimental gingivitis and during a 6-month experimental gingivitis and a 6-month period of optimal oral hygiene. A total of 126 biopsies was obtained, from which 378 sections were cut at 2 microns for stereological analysis. At low magnification, reference volumes were estimated using point counting procedures and expressed as mm3 of gingiva per mm length of vestibular gingiva, in a vestibulo-lingual plane. At higher magnification the ratio between the volume of vessels and connective tissue was calculated. The final results were expressed as mm3 of vessels per mm length of vestibular gingiva, in a vestibulo-lingual plane. The mean vessel volume expressed per unit length of vestibular gingiva ranged from 0.010 to 0.024 mm3/mm. No statistically significant differences in vascular volumes were found between inflamed and non-inflamed gingiva. It was concluded that the changes in vascular architecture during early gingivitis described in the literature had either taken place in the subjects prior to the time of experimentation or that any vascular changes (cytologic or functional) which had taken place may be compensatory for the changes in architecture described in the literature.

Effects of two bacterial products, muramyl dipeptide and endotoxin, on bone resorption in organ culture.

We have compared two components of bacterial cell walls, muramyl dipeptide (MDP) and lipopolysaccharide (LPS), for their effects on bone resorption as measured by the release of previously incorporated 45Ca. MDP is the smallest active component of peptidoglycan, whereas LPS is the active component of endotoxin. Fetal rat long bones were cultured for 5 days in a chemically defined medium supplemented with bovine serum albumin (BSA) or serum. LPS increased 45Ca release at concentrations of 0.03-1.0 microgram/ml. LPS further purified by electrolytic dialysis (ED-LPS) was active at 0.01 microgram/ml. ED-LPS was ineffective at such low concentrations in the presence of serum. The response to MDP was more variable than that to LPS, but bone resorption was stimulated at concentrations of 10(-7)-10(-5) M. MDP was less effective or inactive in medium supplemented with serum. Stereoisomers of MDP that do not have adjuvant activity caused minimal stimulation of bone resorption, whereas 6-0-steroyl MDP stimulated resorption at 10(-8) M. The stimulation of bone resorption by LPS and MDP was not inhibited by indomethacin. Both LPS and MDP increased lysosomal enzyme release in proportion to their effects on 45Ca release. LPS also markedly increased collagenase activity in the medium, but MDP did not. These results indicate that chemically different products of bacterial cell walls can stimulate bone resorption in vitro. These products may be distinguished by differences in dose response curve, serum inhibition, and collagenase release.

Demonstration and preliminary characterization of bone resorbing activity in freeze-dried gingiva of dogs.

The bone resorbing activity of suspensions or supernatants of freeze-dried powdered gingiva was studied by measuring the release of 45Ca from prelabeled fetal rat long bones in organ culture. Two preparations of noninflamed attached gingiva showed no bone resorbing activity, whereas all six preparations of inflamed marginal gingiva tested showed a dose-related stimulation of 45Ca release. Evidence of an osteoclastic mechanism was provided by the inhibition of the bone resorbing activity by calcitonin and cortisol and the minimal activity observed on dead bones. The activity was heat stable and not blocked by human serum. Three different prostaglandin synthetase inhibitors did not inhibit the activity. Immunoassay showed that PGE was present in gingival powder preparations at concentrations in the range 229-2438 pg/mg dry weight. This was insufficient to account for the observed bone resorbing activity by a factor of 50-350. It was concluded that in addition to PGE, inflamed gingiva contains other heat-stable bone resorbing factor(s).

Erythrocyte velocity in vascular networks of young noninflamed dog gingiva.

Measurements of erythrocyte velocity in vascular networks of noninflamed gingiva of deciduous canines of four young dogs were obtained using vital microscopy and high-speed cinephotomicrography. Mean erythrocyte velocity in small gingival vessels was 1.59 +/- 0.29 mm/sec. Differences in erythrocyte velocity of vessels comprising a gingival microcirculation and of vessels within different gingival samples were not significant.