Interstitial hyperthermia of the prostate in combination with brachytherapy : An evaluation of feasibility and early tolerance.

OBJECTIVE: A retrospective study to evaluate the feasibility and toxicity of interstitial hyperthermia (IHT) combined with high-dose-rate (HDR) brachytherapy as the initial treatment for low- and intermediate-risk prostate cancer, and as a salvage therapy in previously irradiated patients with local recurrence. PATIENTS AND METHODS: Between 18 December 2008 and 5 September 2012, 73  prostate cancer patients were treated with interstitial HDR brachytherapy of the prostate combined with IHT. In 54 patients this was the initial therapy for prostate cancer, while the other 19 were treated for local recurrence after previously undergoing external beam radiotherapy (EBRT). Toxicity for the organs of the genitourinary system and rectum was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v. 4.03 within 3 months after treatment. RESULTS: Median follow-up was 15 months (range 3-46). The combination of HDR brachytherapy and IHT was well tolerated. The toxicity profile was similar to that of HDR brachytherapy when not combined with hyperthermia. The most common minor complications were urinary frequency (grade 1: 37 %; grade 2: 22 %), nocturia (three times per night: 29 %; four- or more times per night: 20 %) and transient weakening of the urine stream (grade 1: 36 %; grade 2: 11 %). No early rectal complications were observed in the patient group and the severity of genitourinary toxicity was only grade 1-2. CONCLUSION: Early tolerance of IHT in combination with HDR brachytherapy is good. Further prospective clinical studies should focus on the effects of combining IHT with HDR brachytherapy and the influence of this adjuvant therapy on biochemical disease-free survival, local control and overall survival.

Relationship between succinate transport and production of extracellular poly(3-hydroxybutyrate) depolymerase in Pseudomonas lemoignei.

The relationship between extracellular poly(3-hydroxybutyrate) (PHB) depolymerase synthesis and the unusual properties of a succinate uptake system was investigated in Pseudomonas lemoignei. Growth on and uptake of succinate were highly pH dependent, with optima at pH 5.6. Above pH 7, growth on and uptake of succinate were strongly reduced with concomitant derepression of PHB depolymerase synthesis. The specific succinate uptake rates were saturable by high concentrations of succinate, and maximal transport rates of 110 nmol/mg of cell protein per min were determined between pH 5.6 and 6. 8. The apparent KS0.5 values increased with increasing pH from 0.2 mM succinate at pH 5.6 to more than 10 mM succinate at pH 7.6. The uptake of [14C]succinate was strongly inhibited by several monocarboxylates. Dicarboxylates also inhibited the uptake of succinate but only at pH values near the dissociation constant of the second carboxylate function (pKa2). We conclude that the succinate carrier is specific for the monocarboxylate forms of various carboxylic acids and is not able to utilize the dicarboxylic forms. The inability to take up succinate2- accounts for the carbon starvation of P. lemoignei observed during growth on succinate at pH values above 7. As a consequence the bacteria produce high levels of extracellular PHB depolymerase activity in an effort to escape carbon starvation by utilization of PHB hydrolysis products.

High-frequency-noise-induced hearing loss: a field study on the role of intensity level and accumulated noise dose.

Based on audiometric tests in the range of 10 to 20 kHz, of 106 ultrasound operators, as well as on measurements of high-frequency noise, the problem of safety limits for high-frequency noise exposure was investigated. Analyzing the relation between noise levels of 1/3 octave bands at center frequencies of 10, 12.5 and 16 kHz and the accumulated noise dose on the one hand, and changes of hearing at 10 to 12, 11 to 13 and 14 to 16 kHz respectively, on the other hand, a harmless level up to 80 dB and a harmless noise dose up to 1 unit for people not older than 40 years have been found. For older people this level and this noise dose can be dangerous.

Dynamics of high-frequency hearing loss of operators of industrial ultrasonic devices.

This investigation was aimed at elucidating the dynamics of hearing loss in the range of 500 Hz to 20 kHz of 26 Ultrasonic (Uls)-operators exposed to high-frequency noise exceeding known hygienic limits. Results of audiometric tests performed twice, before and after a period of three years, were compared. The determined hearing-threshold-shift in the range of 500 Hz to 13 kHz could be explained as the effect of aging, whereas in the range of 13 to 17 kHz the stated mean threshold elevation of 2-5 dB, beyond the hearing loss connected with aging within three years, is the consequence of high-frequency noise exposure. On this basis the dynamics of high-frequency hearing loss of 1 dB/year in the case of continued exposure to high-frequency noise could be calculated. Apart from the observed threshold elevation, the fraction of ears responding to acoustic stimuli at the highest frequencies decreases by about 10% with frequency increase of 1 kHz in the range of 13 to 19 kHz. This indicates that the hearing organ is more susceptible to high-frequency noise at the highest hearing frequencies.

High-frequency hearing risk of operators of industrial ultrasonic devices.

Sound and ultrasound emitted by industrial ultrasonic (Uls) devices exceed the known proposed hygienic limits, especially for frequencies 10-20 kHz. The consequence of this may be a negative influence of this energy on the auditory function in the high-frequency hearing range. To determine the hearing risk to Uls operators, an adequate method for testing the hearing threshold from 10-20 kHz has been developed. In order to get reference values, 189 non-exposed persons were tested. On this basis, the hearing thresholds of 55 operators for frequencies 500-20,000 Hz were evaluated. In addition to threshold elevations in the range 10-20 kHz, a decreasing number of subjects responding to stimuli at the highest audible frequencies was observed. The threshold shift at 10-20 kHz of subjects exposed to sound and ultrasound emitted by Uls-devices depends upon the physical parameters of the sound spectrum, time on the job and daily exposure time. No abnormalities were found in the hearing range 500-8000 Hz.