Inhibition factor of ammonification in stored urine with fecal contamination.

Inhibition factors of urea hydrolysis caused by fecal contamination as source of urease were investigated. The urea hydrolysis was described by initial ammonification rate (IAR). Three factors for the inhibition (pH, free ammonia nitrogen (FAN) and salinity) were investigated in this study. It was found that the optimum pH value for the urea hydrolysis was obtained at pH 7 (30 degrees C). Similar results were obtained from pH 5 to pH 8 whereas pH 9 provided a little amount of negative effect on the hydrolysis. Significant effect of the FAN as inhibition factor on the urea hydrolysis was obtained in the urea solution: the hydrolysis was observed within 120 mg-N/l of the FAN level in artificial urea solution with fecal contamination. However in storage process of real urine the urea hydrolysis was observed until the FAN level increased up to 2,000 mg-N/l. Salinity obviously provided negative effect on the urea hydrolysis in stored urine with fecal contamination at 30 degrees C. It was assumed that high concentration of the NaCl (150 g/l) was required to achieve 50% reduction of the IAR.

Experimental study on nitrogen components during composting process of feces.

We measured nitrogen components during composting process of feces in a batch test in which sawdust was used as a matrix. Further decomposition rates of fecal nitrogen and carbon were obtained in the batch tests of different feces loading. In composting material that was a mixture of sawdust and fresh feces, fecal organic matter decomposed to CO2 and fecal nitrogen mineralized to ammonia during the composting process. The biological response of organic matter and nitrogen in the composting material was evaluated by oxygen consumption (OUR) and ammonia production that was a sum of volatilized ammonia gas and ammonia remaining in the composting material. Since composting material contains two different sources of organic matter from feces and sawdust, the OUR by using the sawdust matrix only was evaluated in preliminary tests. The fecal contribution to the OUR in the composting material was therefore calculated by subtraction of the result in the preliminary tests from the one in the composting material. The ammonia production from the fecal nitrogen was obtained by the same procedure. The decomposition rates of input organic matter in feces were approximately 83 and 70% respectively, whereas ammonia production rates were approximately 73 and 58% of input fecal nitrogen. There was an interesting time lag of the peak time between volatilisation rates of ammonia and CO2 during the composting process while fecal carbon and nitrogen simultaneously decomposed to ammonia and CO2 in the composting material.

Time-intensity trade of bilaterally bone-conducted sounds in normal hearing subjects.

OBJECTIVE AND METHODS: In an effort to examine the rules by which information of bilaterally applied bone-conducted signals arising from interaural time differences (ITD) and interaural intensity differences (IID) is combined, data were measured for continuous 500 Hz narrow-band noise at 60 dBHL in 30 normal-hearing subjects using a centering method. Time-intensity trading functions were obtained by means of a sound image shifted towards one side by presenting an ITD, and shifted back to a centered sound image by varying the IID in the same ear. ITD values were varied from -600 to +600 microseconds at 200 microseconds steps, where negative values indicate delays to the right ear. RESULTS: Time-intensity trading functions in response to bone-conducted signals showed significantly lower discrimination thresholds across IIDs, when compared to a control group with applied air-conducted signals. These findings can be interpreted as a constructive interference effect related to the intimate mechanism of bilateral bone conduction, where interaural time differences play a major role. CONCLUSION: Time-intensity trade of bilaterally bone-conducted sounds in normal-hearing subjects is the highly sensitive. The high speed of sound through the skull may be the main reason for the high sensitivity of time-intensity trading.

The effects of tone exposure on the inner ear functions in the guinea pig: impact tone vs. steady state tone.

The damage-risk criterion (DRC) for hearing supposes that sound exposure with equal energy implies equal risk for noise-induced hearing loss (NIHL). We measured cochlear microphonics (CM), compound action potential (CAP), endocochlear potential (EP) and K+ ion concentration in the scala media, to see if the same level of Leq24h (impact tone and steady state tone) induced the same physiological changes in the inner ear function or not. Regarding the equal energy principle (EEP), we also examined if the EEP is appropriate or not at exposure of moderate level tone. We also checked how the time interval between impact tones affects or not the inner ear functions at the same Leq24h tone exposure. Therefore we used exposure at 1 pulse/second or 1 pulse/3 seconds and steady state tone exposure at Leq24h=90, 85 and 80 dB. The results are the following. Both steady state and impact tone exposure causes change of the electrophysiological data. First, CM maximum output voltage after exposure to impact tone of 115 dB (Leq24h=90 dB) was lower than after exposure to a 8 kHz steady state tone of 90 dB. CAP threshold (below 10 microV) obtained after the 115 and 110 dB exposure of impact tone were 5-10 dB higher than that of steady state tone of 90 dB. The negative EP induced by impact tone exposures showed the same tendency as the CM experiments. Having more frequent pulses (1 pulse/second vs. to 1 pulse/3 seconds) showed more inhibition. The K+ concentration time course remained similar to the control when the Leq24h was low (80 dB). Impact tone exposure induced stronger effects to the inner ear at exposure of moderate level tone than that of steady state tone of Leq24h.

Cryosurgery for recurrent prostate cancer following radiation therapy.

Patients with prostate cancer are commonly treated medically or undergo radical prostatectomy and/or radiation therapy. Radiation therapy is usually selected for patients with local or regional disease and patients for whom traditional surgery has failed. The local recurrence of cancer in patients treated with radiation therapy presents a difficult challenge regarding the selection of further treatment options. A commonly applied treatment is salvage prostatectomy, but it can be difficult and complicated, with positive surgical margins occurring in as many as 50 percent of patients and with significant postoperative morbidity. Hormonal therapy, which is not curative, has served as an alternative to surgery in patients who have failed to respond to radiation therapy. Cryosurgery, the destruction of diseased tissue by freezing, is increasingly used both as a first-line therapy and as a second-line therapy (salvage therapy) in patients for whom radiation therapy has failed. Recent reports suggest that cryosurgery may be a useful alternative procedure for treating some of these patients with recurrent cancers. Outcomes of cryosurgery are improving through better instrumentation, surgical technique, and experience. The available data suggest that some patients with radioresistant cancer appear to benefit from the use of cryosurgery as a salvage therapy. Use of this technique has resulted in biochemical disease-free survival for varying periods of some patients who had recurrent prostate carcinoma following radiation therapy; however, morbidity remains high and relatively few patients have had adequate followup. Salvage cryosurgery prospective clinical trials are warranted and would help determine long-term survival benefits and make possible the comparison of cryotherapy patient survival rates with those of untreated biopsy-positive patients.

Light dose and time dependency of photodynamic cell membrane damage.

We have investigated the light dose and time dependency of photodynamic cell membrane damage using electrophysiological methods. This study controls the level of cell membrane damage by precisely administration of the light dose. The photosensitizer used was 5',5"-bis(aminomethyl)-2,2':5',2"-terthiophene dihydrochloride (BAT). A confocal laser scanning microscope was used to provide rapid light activation (< 1 s) and the subsequent membrane damage was monitored using standard patch clamp techniques. In the presence of 49 microM BAT, light levels less than 0.94 J/cm2 led to a reversible depolarization (approximately 20 mV) and reduction of resistance (approximately 10%) within 3 s of illumination. Higher intensities of illumination (> 1.57 J/cm2) caused a complete and irreversible loss of membrane potential and cell membrane resistance within 8 s illumination. The threshold dose of light required to induce cell death by illumination in the presence of BAT was increased in the presence of the antioxidant Trolox-C.

18F-labeled 2-deoxy-2-fluoro-D-glucose positron-emission tomography scans for the localization of the epileptogenic foci.

The localization of epileptogenic foci that are amenable to curative epilepsy surgery may be accomplished by noninvasive surface electroencephalogram (EEG) recordings, clinical observations, computed tomography (CT), magnetic resonance imaging (MRI), and neuropsychologic tests. Other tests, such as invasive EEG, 18F-fluoro-deoxyglucose-positron-emission tomography (FDG-PET or PET) scans, and single-photon-emission computed tomography (SPECT) scans, have also been used at various epilepsy centers to help identify candidates who might benefit from such surgery. Interictal PET scans have demonstrated hypometabolism in areas concordant with the epileptogenic foci indicated by other diagnostic tests such as EEG and MRI. However, PET scans have also shown no abnormality in many patients with EEG-indicated epileptogenic foci; in others, the scans have shown abnormal metabolism in areas that were discordant with the epileptogenic foci. Although substitution of the noninvasive PET scan for the invasive EEG recordings would be desirable, the available data were insufficient to determine whether PET scans might serve as a reliable substitute for EEG. A positive PET scan might contribute independent information for identifying the epileptogenic site but could be noncontributory or confusing when hypometabolism is not seen or is seen in presumably normal brain areas. It is not evident from the data in the literature to what extent confirmatory PET scan findings might contribute to the management of patients with complex partial seizures.

[An autopsy case of intravascular malignant lymphomatosis with hemophagocytic syndrome, mental confusion and liver dysfunction].

A 66-year-old Japanese man was admitted to Hitachi General Hospital because of fatigue, fever, edema, and icterus. A blood examination showed anemia, leukocytosis, and hyperbilirubinemia. Antibiotics did not alleviate the inflammatory symptoms. On the 13th hospital day, the patient demonstrated mental confusion, with progressive anemia and thrombocytopenia. Bone marrow aspiration revealed an increase of macrophages showing erythrophagocytosis. A diagnosis of hemophagocytic syndrome was made, but no viral infection or hematological malignancy could be detected. The patient was treated with gamma-globulin and methylprednisolone for hemophagocytic syndrome, but died of respiratory insufficiency with progressive hyperbilirubinemia and trombocytopenia on the 29th hospital day, A postmortem examination showed proliferation of lymphoma cells within the small blood vessels of the brain, lungs, liver, and many other organs, but the bone marrow was not involved. An immunohistochemical examination resulted in a diagnosis of intravascular malignant lymphomatosis (IML) of B cell origin. No viral infection was detected with in situ hybridization methods. Although IML occasionally accompanies thrombocytopenia, infiltration of lymphoma cells in the bone marrow is rare. Lymphoma associated hemophagocytic syndrome may cause cytopenia in some patients with IML, as indicated in this case.

Experimental study on the effects of gentamicin injection on the guinea-pig: electrophysiological studies.

The inner ear distortion induced by gentamicin (GM), a type of aminoglycoside antibiotic, was examined in guinea-pigs. Previous studies which investigated the function of the eighth cranial nerve and organ of Corti using cochlear microphonics (CM) and compound action potential (CAP) reported ototoxicity following experimental exposure to GM. In this report, the effects of GM on the cochlea and the eighth cranial nerve were investigated systematically by measuring CM, CAP, summating potentials induced by 90 dB (SPL) tone burst, endocochlear potential (EP) and K+ ion concentration of the endolymph. Guinea-pigs were treated with a daily intramuscular injection of GM (60 mg in 1.5 cc) at a dose of 60 mg/kg during different treatment periods. The maximum output voltage of AP was decreased by injection of GM (60 mg/kg x 24). A decrease in the CM maximum output voltage and the elevation of CM pseudothreshold were typically seen after GM injection at a test frequency of 8 kHz and a decrease in CAP was also observed. Changes in EP during 3 min anoxia were observed, in particular a decrease in the absolute value of the negative potential. The endolymph K+ ion concentration remained unchanged. These findings indicate that the diffusion potentials decreased at the same time as reduction of maximum output voltage in CM induced by GM injection.

An electrophysiological study of the effects of acute methylmercury chloride exposure on the function of the guinea pig cochlea.

The inner ear function of methylmercury chloride (MMC)-exposed guinea-pigs was examined in this study. Previous studies which investigated the function of the eighth cranial nerve and Corti-organ using cochlear microphonics (CM), compound action potential (CAP) and measurement of endocochlear potential (EP) reported ototoxicity following experimental exposure to MMC. In this report, the effect of MMC on the cochlea and the eighth cranial nerve were investigated systematically by measuring CM, action potential (AP), EP and K+ ion concentration of the endolymph. Guinea-pigs were injected with 5 mg/kg MMC (using 0.2% solution) twice a week for 1-3 weeks. The maximum output voltage of AP was decreased by injection of MMC (5 mg/kg x 6). A decrease in the CM maximum output voltage and the elevation of CM pseudothreshold was seen after MMC injection. Changes in EP during 3 min anoxia were observed, especially a decrease in the absolute value of the negative potential. The endolymph K+ ion concentration remained unchanged. These findings indicate that the diffusion potentials decreased and at the same time was reduced the maximum output voltage in CM induced by MMC injection (5 mg/kg x 6) in this experiment.

Dengue hemorrhagic fever in Jakarta, Indonesia in 1988: isolation of dengue virus from patient whole blood using cell cultures.

During an outbreak of dengue hemorrhagic fever (DHF) in Jakarta, Indonesia in 1988, we attempted to isolate dengue virus using mosquito cells and a medium containing heparin. Whole blood, immediately after being drawn from patients, was inoculated into Aedes albopictus cell cultures temporarily maintained in the heparin-containing medium. The overall virus isolation rate was 25% (17 of 69) samples collected within three days after admission of the patients to hospital. No virus was obtained thereafter. The successful virus isolation was apparently not related to titers of anti-dengue virus hemagglutination-inhibiting antibodies present in patients' sera. The viruses were recovered from cases of each of the four World Health Organization grades of DHF without significant differences. The technique is simple and easily performed at bedside.

Combined effects of acute lead acetate exposure and tone exposure of the guinea pig cochlea.

Lead acetate exposure to humans can induce various disorders of the cranial nerves. Although vertigo and sensorineural deafness have been reported in lead workers, the dose effects of lead acetate on the cochlea and eighth cranial nerve are not well documented. We investigated the effects of lead acetate on the male albino Hartley guinea pig cochlea by measuring cochlear microphonics (CM), whole nerve action potential (AP), endocochlear potential (EP) and K+ ion concentration of the endolymph. Animals were given lead acetate by intraperitoneal injection as 20 mg/week for 4 consecutive weeks. A total dose < 80 mg did not induce electrophysiological changes in the cochlea. However, the AP output voltage (N1) decreased if the 80 mg lead acetate treatment was followed by an 80 dB tone exposure at 6 kHz during 24 h. A change was observed in CM and EP but not K+ ion concentration in the scala media.

A comparative study on the effect of pure-tone exposure of the guinea pig cochlea.

Electrophysiological methods were applied to 160 healthy adult male guinea pigs in order to investigate the effects of pure-tone exposure for 24 h on the inner ear. A reduction in cochlear microphonics (CM), action potential (AP) and endocochlear potential was observed following exposure to 110 dB at 100 Hz, 100 dB at 200 and 600 Hz and 95 dB at 2 kHz. The observed K+ endolymphatic concentration during 40 min anoxia remained unchanged. In contrast K+ decreased in control animals and following exposure to pure tones varying from 110 dB at 60 Hz to 85 dB at 2 kHz. These findings indicate that high frequency tones have a greater effect on inner ear functions than those of lower frequency, decreasing the maximum output voltage of CM and AP but not changing K+ endolymphatic concentration.

Immediate changes in subcellular structures of transplanted tumors following photodynamic and laser hyperthermic therapy.

BACKGROUND AND OBJECTIVE: To further understand the precise process of the tumor cell degeneration after photodynamic therapy (PDT), laser hyperthermic therapy (LH), and combined treatments using an Nd:YAG laser. It is important to examine initial morphological alteration of tumor cells after these treatments. STUDY DESIGN/MATERIALS AND METHODS: In this study, nude mice bearing HeLa cell tumors were treated with PDT, LH, and combined treatments of the two. Tumor tissues obtained immediately after these treatments were analyzed using electron microscopy and morphometry. RESULTS: In the combined treatments, which produced more severe effects on tumor cells, morphological features of apoptosis such as cytoplasmic condensation, blebs, and apoptotic bodies appeared in the cells, although the typical alteration in the nuclear chromatin was not seen. CONCLUSION: Cytoplasmic alterations may proceed more rapidly than nuclear alterations in the cellular degeneration induced by the single or combined treatments of PDT and LH.

Proton beam therapy for patients with esophageal carcinoma.

Fifteen patients with esophageal carcinoma (superficial, six cases; advanced, nine cases) were treated with 250 MeV proton beam irradiation with or without external x-ray irradiation (12 MV linear accelerator) from October, 1985, to May, 1991. Eleven patients were initially treated with x-ray at doses of 16.2-50.4 (mean 42.5) Gy, followed by proton beam at doses of 30.0-52.9 (mean 37.6) Gy. The other four patients were treated with proton beams alone at total doses of 75.0-88.5 (mean 81.4) Gy. The mean total dose for the 15 patients was 80.4 Gy. As a result, the primary tumor lesions of all 15 patients disappeared and complete responses were obtained. Approximately four to five months later, nine of the 15 patients developed esophageal ulcer formations at the circumferences of their primary lesions. The ulcerations were healed, however, by conservative management. There was no evidence of local recurrence throughout the observations on six cases of superficial carcinoma. Among nine advanced carcinoma patients, three relapsed into esophageal carcinoma. Recurrences were observed eight, 16 and 44 months, respectively, after the treatment. Ten of the 15 patients died, but eight died of other diseases. Three of four cases at autopsy did not show any cancer cells in irradiated primary lesions. Four of the 15 patients lived for over five years. The results suggest that a high dose of irradiation delivered by a well-defined proton field could result in improved local control and long-term survival in esophageal carcinoma without undue risk of injury to primary and adjacent organs.

The effect of 6 kHz tone exposure on inner ear function of the guinea pig: relation to changes in cochlear microphonics, action potential, endocochlear potential and chemical potentials of K(+)-ions and Na(+)-ions, using a double-barrel glass electrode.

Using 97 male albino guinea pigs and applying electrophysiological methods, the effects of a 6 kHz tone were investigated at a moderate sound pressure level to the inner ear during a 24-h exposure time. Following exposure to the 6 kHz tone at 90 dB, cochleas showed decreased maximum output voltage of cochlear microphonics (CM) and action potential (AP). In the endolymph, K+ ion and Na+ ion concentrations remained unchanged during 40 min anoxia and 90 dB tone exposure. At 80 dB sound exposure decreases in maximum output voltage of CM and AP and decreases in the absolute value of EP could not be detected. Endolymph K(+)-ion Na(+)-ion concentrations were also unchanged. These findings indicate that diffusion potentials are induced at the same time as decreases of maximum output voltage in CM induced by exposure to sound at 90 dB.