[Effect of Sterilized Water on the Removal of Staphylococcus Aureus Attached to the Inner Surface of the Enteral Nutrition Tubes].

OBJECTIVE: The purpose ofthis study is to determine whether Staphylococcus aureus(S. aureus)can be removed completely from the inner surface of the enteral nutrition tubes using sterilized water. METHODS: A bacterial solution of S. aureus in saline was prepared. The enteral nutrition tubes were later soaked in this solution for 1 hour. After the solution was drained, bacterial count ofthe tube was determined. The inner surfaces ofthe tubes were later flushed 10 times with sterilized water. The bacterial load of the tubes was determined after flushing. After 18 hours, the viable bacteria on the insides of the tubes were enumerated. RESULTS: One hour after the initial inoculation, 62.6±26.0% oft he S. aureus survived. Some bacteria remained viable on the tubes after 10 flushes with sterilized water. Eighteen hours after the flushes, viable bacteria could be detected on the inside ofthe tubes. CONCLUSION: To ensure the safe use ofthe enteral nutrition tubes, it is important not to recycle the tubes or to disinfect the tubes after every meal.

Effect of turpentine-induced fever during the enamel formation of rat incisor.

OBJECTIVE: Some epidemiological studies have indicated that diseases resulting in prolonged and sustained fever, such as exanthemata, respiratory infections and otitis media in infantile period or childhood are likely to have a marked deleterious effect on enamel formation, but the relationship between fever and enamel defects is unknown. The purpose of the present study was to induce a persistent high fever and examine the effects on the developing tooth enamel. METHODS: Twenty male Wistar rats weighting 140+/-10 g were used in this study. For the experimental group, a dose of 2.3 ml/kg steam-distilled turpentine was subcutaneously injected into both hind limbs five times at 12h intervals. Control rats received 2.3 ml/kg of sterile saline into the same injection site. The rectal temperatures of animals were measured at the febrile period. After constant periods, the animals were sacrificed, and the mandibular incisors were examined by contact microradiography (CMR) and histological observation. RESULTS: The febrile state lasted for 57 h and the average temperature rose 1.51 degrees C higher than that of the control group. The ground sections, semi-thin and ultra-thin sections of mandibular incisors were prepared and the enamel was observed. The microradiographs showed a radiolucent line along with the incremental line in the enamel. Moreover, microscopic examination indicated disorientation of enamel prism and crystal-free area within this radiolucent lesion. CONCLUSIONS: Persistent high fever pattern was established firmly by the turpentine injections and the process of enamel formation was influenced by the febrile period.

[Rapid and simultaneous determination method for analysis of minerals in infant formula using ICP-MS].

A rapid and simultaneous method by using inductively coupled plasma mass spectrometry (ICP-MS) was developed for determination of 19 elements in infant formula. Fast and efficient sample digestion was achieved by a microwave-assisted nitric acid procedure. An acetic acid was added to both these treated solutions and standard solutions as a countermeasure for carbon charge transfer in As, Se elements. The observed calibration curves showed good linearity (r(2)>0.9993) and the quantification limit was low. The recoveries of elements were 95.0-108% and the relative standard deviations (RSD) of this method were 0.3-4.2%. The analyzed values were in good agreement with the certified values in a NIST standard reference material. This study showed that the ICP-MS method is useful for major to trace multi-elemental determination in infant formula.