Broken thermometer in foot: a source of mercury poisoning.

A 17-year-old boy was referred after jumping from a ladder onto the ground, crushing a medical thermometer with his right foot. Some days later, he complained of loss of appetite and weakness. A radiograph of the affected foot demonstrated radiopaque densities. Blood and 24-h urine assays for mercury demonstrated toxic levels. Chelation therapy cured the patient dramatically.

Case series of mercury toxicity among children in a hot, closed environment.

Mercury poisoning is much more prevalent in the general population than possibly many physicians realize. We present data on 26 pediatric cases with mercury intoxication from exposure to mercury by inhalation or skin contact as a result of a broken thermometer in a school laboratory. This is the largest pediatric series in Turkey. During a 3-month period, the study team observed the children for clinical symptoms, physical findings, and blood and mercury levels. Of all patients, 21 inhaled, 3 inhaled and touched the element, and 2 took the mercury home. Sixteen children were symptomatic at admission, although blood mercury levels in the symptomatic children were higher than those in asymptomatic children (P = 0.003). The urine mercury levels were not statistically different between the groups at the admission (P > 0.05). The exposure times were 3.5 and 2 hours for symptomatic and asymptomatic children, respectively (P = 0.003). The 2 children who took the mercury home had the highest blood mercury levels and the most prolonged exposure time. N-acetylcysteine and chelation treatments were started in 21 children who had symptoms of mercury intoxication and high mercury levels in their blood or urine. No adverse effects were observed during chelation therapy. Prompt removal of children from contaminated environments and proper decontamination or elimination of devices containing large amounts of mercury from schools are necessary to prevent serious complications caused by exposure to mercury.

The development of a high impedance all ceramic thermistor resistant to microwave irradiation: its possible medical application.

We developed a prototype all ceramic thermistor (ACT) composed of a silicon carbide (SiC) ceramic thermistor and SiC ceramic fibre-lead wires in order to accurately measure tissue temperature during microwave heating treatment. High density SiC ceramics reflects electromagnetic waves and manifests microwave resistant properties. The resistance of the SiC ceramic thermistor is approximately 15 M Ohm at 20 degrees C and has a sensitivity of approximately 200 K Ohm/ degrees C. SiC ceramic fibre resistance is approximately 40 K Ohm/cm, whereas its sensitivity is approximately 10 Ohm/ degrees C-cm, significantly lower than that of the SiC ceramic thermistor. The resistance of the SiC ceramic fibre is stable. This enables the ACT to be designed with the two-probe method instead of the four-probe method which was adopted in the Bowman type thermistor, resulting in a greatly simplified model. The measurement error caused by the temperature dependence of SiC ceramic fibre is < 0.02 degrees C. The ACT was inserted into muscle-equivalent agar phantom and into gluteal muscles of rabbits, and microwave irradiation was carried out. We recorded the phantom and tissue temperature without disturbance by the electromagnetic field for heating. This prototype ACT appears promising for its possible clinical applications in such settings as hyperthermic cancer therapy in man.

Problems associated with CT-guided catheter insertions.

From October 1987 to August 1991 a total of 141 closed-tip catheters were inserted into deep-seated or half-deep-seated tumours in 95 treatment areas. Most of the catheters (n = 79) were implanted in the pelvic region. In 139 punctures no clinical evidence of bleeding was seen. A transient blood loss was evident in only two patients. In addition, no nerve injury was observed. The problems with 141 implanted catheters were evaluated. Nineteen catheters (13%) were lost during the treatment series. In five displacement of the catheters was verified by repeat CT scans during the whole treatment. Eight catheters had to be removed due to infection. In two patients with advanced disease who were receiving a combination of chemotherapy and hyperthermia a strong inflammatory response was evident. Another patient developed an acute pancreatitis after catheter insertion. No metastasis in the invasive tracks has been seen in the follow-up period. In conclusion the insertion of closed-tip catheters by CT guidance is a sure and well-tolerated method. There were a few problems only with the implanted catheters throughout the whole treatment series.

Risk of tumour growth along thermometry catheter trace: a case report.

A patient with recurrent rectal cancer was treated with the combination of radiotherapy plus hyperthermia. Intratumoral thermometry probes were introduced within closed-tip catheters, inserted through the buttocks under computed tomography (CT) control. Catheters were fixed to the skin to stay in place during the whole treatment series. At the end of the radiotherapy series, tumour progression was apparent. Seven months following treatment, tumour growth was visible at the insertion site of one of the catheters. This finding indicates that catheters should not be placed outside the treatment volume involved in any locally curative treatment.