Radiation exposure levels in close proximity to therapeutic patients treated for thyroid carcinoma with high dose I-131

High dose I-131 therapy is administered to thyroid cancer patients after thyroidectomy. In the treatment process when a radiopharmaceutical is administered to patients, they become a mobile source of radiation. After the treatment, contamination may arise from large amount of activity, which is excreted during the period of hospitalization. To reduce the rate of exposure it is essential to monitor workplace. This study determines the rate of radiation exposure in the room where the patient stays during the period of hospitalization as well as the adjacent rooms and surrounding areas. DOI: http://dx.doi.org/10.3329/bjnm.v17i1.22491 Bangladesh J. Nuclear Med. 17(1): 50-54, January 2014

Influence of Blood Contamination on Bond Strength of a Self-Etching System

Objectives: To detect the influence of blood contamination (BC) on the bond strength (BS) of a selfetching bonding system (SES) to enamel and dentine.Methods: 25 human molars were longitudinally sectioned on the mesio-distal axis in order to obtain 50 specimens, which were embedded in acrylic resin. At first, the specimens were ground to expose a flat surface of enamel, and a bond strength test was performed. Afterwards, the samples were ground again in order to obtain a flat surface of dentine. Ten groups (total: n=100) were assigned according to substrate (enamel and dentine), step in the bonding sequence when contamination occurred (before the acidic primer and after the bonding resin), and contamination treatment (dry or rinse and dry procedure). Fresh human blood was introduced either before or after SES application (Clearfil SE Bond) and treated with air drying, or by rinsing and drying following application. Composite resin (Filtek Z-250,3M ESPE) was applied as inverted, truncated cured cones that were debonded in tension.Results: The mean tensile BS values (MPa) for enamel/dentine were 19.4/23.0 and 17.1/10.0 for rinse-and-dry treatment (contamination before and after SES, respectively); while the measurements for the dry treatment, 16.2/23.3 and 0.0/0.0 contamination before and after SES, respectively.Conclusions: It was determined that blood contamination impaired adhesion to enamel and dentine when it occurred after bond light curing. Among the tested contamination treatments, the rinseand- dry treatment produced the highest bond strength with BC after SES application, but it was not sufficient to recover the BS in the contamination-free group. (Eur J Dent 2010;4:280-286)

A water contamination incident in Oslo, Norway during October 2007; a basis for discussion of boil-water notices and the potential for post-treatment contamination of drinking water supplies

Over a 5 day period in October 2007 a boil-water notice was served on the majority of Oslo, capital city of Norway, as a result of a combination of bacteriological findings (coliforms, intestinal enterococci, and E. coli), and very low numbers of Cryptosporidium oocysts and Giardia cysts in 10 L water samples taken from the water distribution network. The water source had been regularly monitored for these parasites and generally found to be negative. Over 460,000 residents were affected by the boil-water notice, as were many thousands of businesses. Despite an extensive outbreak of waterborne giardiasis in Bergen, Norway during 2004/2005, occurrence of parasites in Norwegian drinking water supplies has apparently continued to be considered to be of minimal relevance by Norwegian health authorities. Here we describe the background and occurrence of the episode in Oslo, including the species of Cryptosporidium detected, and use this event, in conjunction with incidents from other countries, as a basis to discuss the following issues: 1) under which circumstances should the occurrence of Cryptosporidium oocysts and Giardia cysts in water supplies trigger the issue of a boil-water notice, and 2) the possibilities and probabilities of post-treatment contamination events in the water distribution network.

Differences between rat alveolar and interstitial macrophages 5 wk after quartz exposure

Macrophages play an essential role in pulmonary host defense. We investigated differences between rat alveolar (AM) and interstitial (IM) macrophages after exposure in vivo to quartz, an inducer of intensive alveolitis. Rats were exposed to 0.5 ml of saline without ( n = 8) or with ( n = 8) 10 mg of quartz by intratracheal instillation. In a third group ( n = 8), 10 mg of surfactant were added to the quartz mixture. Five weeks later, AM were recovered by bronchoalveolar lavage and IM by mechanical fragmentation of the lung, followed by enzymatic treatment. Contamination of AM to the IM fraction was calculated to be 12–15%. After quartz exposure, the expression of major histocompatibility complex class Ia was increased in both AM and IM fractions. The receptor corresponding to human complement receptor 3 increased in AM after quartz exposure, and AM from quartz-exposed animals had a lower metabolic activation. Our findings indicate that IM are immunocompetent cells and that differences between AM and IM fractions occur upon quartz-induced inflammation. This response is not affected by addition of surfactant.

An outbreak of waterborne cryptosporidiosis caused by post-treatment contamination

SUMMARYAn outbreak of waterborne cryptosporidiosis affecting 27 persons, diagnosed stool positive, occurred in Ayrshire in April 1988. Twenty-one of the 27 confirmed cases required some form of fluid replacement therapy. Local general practitioners indicated a two- to fivefold increase in diarrhoeal disease during the outbreak, and following enquiries made by Environmental Health Officers it became apparent that many hundreds of people had suffered a diarrhoeal illness at that time.Cryptosporidiumspp. oocysts were detected in the treated chlorinated water supply system, in the absence of faecal bacterial indicators. Oocyst contamination of a break-pressure tank containing final water for distribution was the cause of this waterborne outbreak. An irregular seepage of oocyst-containing water, which increased during heavy rains, was the cause of the break-pressure tank contamination, rather than a failure of the water-treatment processes. The waterborne route should be considered when clusters of cryptosporidiosis associated with potable water occur. Waterborne cryptosporidiosis can occur in the absence of other faecal indicators of contamination.

Methodologic Standards for Controlled Clinical Trials of Early Contact and Maternal-Infant Behavior

To provide an objective evaluation of published studies on the effect of early contact on subsequent maternal-infant behavior, a set of 11 methodologic standards generally applicable to controlled clinical trials of perinatal care was developed. Sixteen reports of early contact trials were assessed and seven of the 11 standards were found to be satisfactorily fulfilled. The four "problem" standards were: adequate definition of subjects, randomization, subject bias, and treatment contamination (care giver) bias. Of the five best trials fulfilling eight or more of the standards, three reported a beneficial effect of early contact, while two demonstrated no effect. The evidence that early contact improves subsequent maternal-infant behavior thus remains inconclusive. It is urged that for future research in this domain more attention be given to adequate subject definition, strict randomization procedures, and safeguards against bias by the subjects or their care givers.