Long-term outcomes of delayed clozapine initiation in treatment-resistant schizophrenia: a multicenter retrospective cohort study

BACKGROUND

Clozapine is the only antipsychotic medication with proven efficacy against treatment-resistant schizophrenia. This multicenter retrospective cohort study aimed to evaluate the impact of a delay in clozapine initiation on long-term outcomes.

METHODS

Patients who initiated clozapine treatment between July 2009 and December 2018 were included in this study. According to the length of time from the diagnosis of schizophrenia to clozapine initiation, the patients were categorized into one of three groups: early (≤ 9 years), intermediate (10-19 years), and late (≥ 20 years) initiation. The endpoints were psychiatric rehospitalization and all-cause clozapine discontinuation within 3 years. Hazard ratios (HR) and 95% confidence interval (CI) were estimated using the Fine and Gray method or the Cox proportional hazards model.

RESULTS

The incidence rates of rehospitalization within three years, according to the cumulative incidence function, were 32.3% for early, 29.7% for intermediate, and 62.2% for late initiation, respectively. Late initiation had a significantly higher risk of psychiatric rehospitalization than early initiation (HR, 2.94; 95% CI, 1.01- 8.55; P = 0.016 by the Gray's test). The risk of psychiatric rehospitalization was not significantly different between the early and intermediate initiation groups. The incidence rate of all-cause clozapine discontinuation within three years using the Kaplan-Meier method was 13.0% for early, 10.6% for intermediate, and 20.1% for late initiation. The risk of all-cause clozapine discontinuation was not significantly among the groups. The late initiation group had more patients discontinuing because of death due to physical diseases than the other groups.

CONCLUSIONS

The study suggests that clozapine should be initiated promptly in patients with treatment-resistant schizophrenia to prevent psychiatric rehospitalization during long-term treatment. Further prospective studies with appropriate consideration of confounding factors and large sample sizes are needed to strengthen the evidence.

Widespread White Matter Aberrations Are Associated with Phonemic Verbal Fluency Impairment in Chronic Traumatic Brain Injury

Microstructural white matter (WM) disruption and resulting abnormal structural connectivity form a potential underlying pathology in traumatic brain injury (TBI). Herein, to determine the potential mechanism of cognitive deterioration in TBI, we examined the association of damage to specific WM tracts with cognitive function in TBI patients. We recruited 18 individuals with mild-to-moderate/severe TBI in the chronic phase and 17 age-matched controls. We determined the pattern of WM aberrations in TBI using tract-based spatial statistics (TBSS) and then examined the relationship between cognitive impairment and WM damage using the threshold-free cluster enhancement correction in TBSS. TBSS analysis showed that TBI patients exhibited WM aberrations in a wide range of brain regions. In the majority of these regions, lower fractional anisotropy (FA) largely overlapped with increased radial diffusivity, but not with axial diffusivity. Further, voxel-wise correction in TBSS demonstrated that higher FA values were associated with better performance in the phonemic verbal fluency task (VFT) in widespread WM regions, but not with the semantic VFT. Despite variation in the magnitude and location of brain injury between individual cases, chronic TBI patients exhibited widespread WM aberrations. We confirmed the findings of previous studies that WM integrity is lower across the spectrum of TBI severity in chronic subjects compared to controls. Further, phonemic VFT may be a more sensitive cognitive measure of executive dysfunction associated with WM aberrations in TBI compared with semantic VFT.

Brain functional alterations observed 4-weekly in major depressive disorder following antidepressant treatment

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous condition. Identifying the brain responses to antidepressant treatment is of particular interest as these may represent potential neural networks related to treatment response, forming one aspect of the biological markers of MDD. Near-infrared spectroscopy (NIRS) is suitable for repeated measurements with short intervals because of its noninvasiveness, and can provide detailed time courses of functional alterations in prefrontal regions.

METHODS

We conducted a 12-week longitudinal study to explore prefrontal hemodynamic changes at 4-week intervals following sertraline treatment in 11 medication-naïve participants with MDD using 52-channel NIRS.

RESULTS

While all participants achieved remission after treatment, intra-class correlation coefficient of oxygenated hemoglobin [oxy-Hb] values throughout the 12-week observation was moderate at the spatially and temporally contiguous cluster located in the left inferior frontal and temporal gyri. There was a significant negative correlation between mean [oxy-Hb] values in the significant cluster at 4 weeks and changes in Hamilton Rating Scale for Depression total score from 4 to 8 weeks (r = -0.73, P = 0.011) and from 4 to 12 weeks (r = -0.63, P = 0.039).

LIMITATIONS

Without healthy controls for comparison, we were unable to fully evaluate whether improvement of [oxy-Hb] activations after treatment in MDD reached normal levels or not.

CONCLUSION

Our NIRS findings of detailed prefrontal hemodynamic alterations over short interval observations such as 4 weeks may have revealed potential trait marker for MDD and biological maker for predicting clinical response to sertraline treatment in MDD.

The intrinsic microglial clock system regulates interleukin-6 expression

Similar to neurons, microglia have an intrinsic molecular clock. The master clock oscillator Bmal1 modulates interleukin-6 upregulation in microglial cells exposed to lipopolysaccharide. Bmal1 can play a role in microglial inflammatory responses. We previously demonstrated that gliotransmitter ATP induces transient expression of the clock gene Period1 via P2X7 purinergic receptors in cultured microglia. In this study, we further investigated mechanisms underlying the regulation of pro-inflammatory cytokine production by clock molecules in microglial cells. Several clock gene transcripts exhibited oscillatory diurnal rhythmicity in microglial BV-2 cells. Real-time luciferase monitoring also showed diurnal oscillatory luciferase activity in cultured microglia from Per1::Luciferase transgenic mice. Lipopolysaccharide (LPS) strongly induced the expression of pro-inflammatory cytokines in BV-2 cells, whereas an siRNA targeting Brain and muscle aryl hydrocarbon receptor nuclear translocator-like protein 1 (Bmal1), a core positive component of the microglial molecular clock, selectively inhibited LPS-induced interleukin-6 (IL-6) expression. In addition, LPS-induced IL-6 expression was attenuated in microglia from Bmal1-deficient mice. This phenotype was recapitulated by pharmacological disruption of oscillatory diurnal rhythmicity using the synthetic Rev-Erb agonist SR9011. Promoter analysis of the Il6 gene revealed that Bmal1 is required for LPS-induced IL-6 expression in microglia. Mice conditionally Bmal1 deficient in cells expressing CD11b, including microglia, exhibited less potent upregulation of Il6 expression following middle cerebral artery occlusion compared with that in control mice, with a significant attenuation of neuronal damage. These results suggest that the intrinsic microglial clock modulates the inflammatory response, including the positive regulation of IL-6 expression in a particular pathological situation in the brain, GLIA 2016. GLIA 2017;65:198-208.

Clock genes influence gene expression in growth plate and endochondral ossification in mice

We have previously shown transient promotion by parathyroid hormone of Period-1 (Per1) expression in cultured chondrocytes. Here we show the modulation by clock genes of chondrogenic differentiation through gene transactivation of the master regulator of chondrogenesis Indian hedgehog (IHH) in chondrocytes of the growth plate. Several clock genes were expressed with oscillatory rhythmicity in cultured chondrocytes and rib growth plate in mice, whereas chondrogenesis was markedly inhibited in stable transfectants of Per1 in chondrocytic ATDC5 cells and in rib growth plate chondrocytes from mice deficient of brain and muscle aryl hydrocarbon receptor nuclear translocator-like (BMAL1). Ihh promoter activity was regulated by different clock gene products, with clear circadian rhythmicity in expression profiles of Ihh in the growth plate. In BMAL1-null mice, a predominant decrease was seen in Ihh expression in the growth plate with a smaller body size than in wild-type mice. BMAL1 deficit led to disruption of the rhythmic expression profiles of both Per1 and Ihh in the growth plate. A clear rhythmicity was seen with Ihh expression in ATDC5 cells exposed to dexamethasone. In young mice defective of BMAL1 exclusively in chondrocytes, similar abnormalities were found in bone growth and Ihh expression. These results suggest that endochondral ossification is under the regulation of particular clock gene products expressed in chondrocytes during postnatal skeletogenesis through a mechanism relevant to the rhythmic Ihh expression.

Selective upregulation of Per1 mRNA expression by ATP through activation of P2X7 purinergic receptors expressed in microglial cells

Clock genes are believed to play a pivotal role in the generation and oscillation of circadian rhythm as a central clock in the hypothalamic suprachiasmatic nucleus in the mammalian brain. In this study, mRNA expression was for the first time demonstrated with clock genes in both cultured murine microglia and microglial cell line BV-2 cells. Exposure to ATP transiently increased Period-1 (Per1) mRNA expression without affecting that of other clock genes in BV-2 cells, while a similarly transient increase was shown in Per1 mRNA expression in a manner sensitive to P2X7 purinergic receptor antagonists in cultured microglia exposed to ATP. In BV-2 cells transfected with a Per1 promoter luciferase reporter plasmid, ATP significantly increased luciferase activity in a manner sensitive to a P2X7-receptor antagonist. In both microglia and BV-2 cells, a significant increase by ATP was seen in the immunocytochemical fluorescence intensity of cells expressing Per1 protein, with mRNA expression of different P2 receptors including P2X7. Per1 siRNA significantly decreased the number of cells with processes in BV-2 cells exposed to ATP. These results suggest that ATP selectively promotes Per1 expression through gene transactivation after stimulation of P2X7 purinergic receptors in microglial cells.

The Characteristics of Amorphous Silicon TFT and its Application in Liquid Crystal Display

An amorphous silicon TFT particularly suited for the full color liquid crystal display driver has been developed and reported here. Various fundamental factors involved in the a-Si TFT, such as the effects of structure, materials, and the method of fabrications were reviewed and investigated in terms of the field effect mobility, the threshold voltage and the reliabilities. An inverted-staggered TFT structure was employed for the purpose wherein the interface states between two layers was successfully lowered by employing the successive deposition procedures of SiNx gate insulator on the a-Si layer. Proper ohmic contacts and the blocking of hole injections were accomplished by forming a n+ layer between the a-Si layer and the source/drain metal electrodes which consists of a double layer of Al/MoSi2 in order to prevent the aluminum diffusion into the a-Si layer during the 300°C heat treatment at the succeeding fabrication processes. The degradation of display images due to the high intensity backlights was minimized by employing a light shielding layer and by making the thickness of a-Si layer 200 Å against the direct sunlight of up to 100,000 luxes. Stable actual performances of TFT for more than 4000 hours at 80 °C were confirmed. The development of a color LCD TV driven by this TFT is also reported.

Light-Emitting Diodes Using Semiconducting Oligothiophenes

The light-emitting diodes (LEDs) using semiconducting oligothiophenes, dimethylquater-thiophene (DMQtT, tetramer), dimethylquinquethiophene (DMQqT, pentamer) and dimethyl-sexithiophene (DMSxT, hexamer), have been investigated. These oligomers were deposited on ITO-coated glass in ultra high vacuum and an aluminum electrode was subsequently vacuum-deposited on top of the oligomers. These structures have the diode configuration with Schottky barrier between the oligomers and aluminum.

The LED using DMSxT shows good rectifying feature with the rectifying ratio of 1500 at ±10V.Red-orange emission is clearly observed above 4V bias. In this LED, DMSxT acts not only as an emitting layer but also as a hole transport layer. We have also fabricated and studied alternate layered structures of DMSxT/DMQtT and DMSxT/DMQqT as the emitting layer. In these configurations, the carrier recombination can be modulated because both DMQtT and DMQqT have energy gaps wider than that of DMSxT.The quantum efficiencies (photons emitted per carriers injected) of the LEDs using DMSxT/DMQtT and DMSxT/DMQqT are about one hundred times and one thousand times larger than that of the LED solely based on DMSxT, respectively. These results indicate that the layered structures are advantageous in increasing quantum efficiency of the emission.

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.

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.

[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.

Molecular comparison of dengue type 1 Mochizuki strain virus and other selected viruses concerning nucleotide and amino acid sequences of genomic RNA: a consideration of viral epidemiology and variation

Dengue-1 (D1) Mochizuki strain was examined for its nucleotide and amino acid sequences of genomic RNA and the data obtained were compared with those of other selected virus strains reported previously. Genomic regions corresponding to C, preM and M proteins were the major subjects of study. Parts of E protein were additionally examined. Among the D1 viruses investigated, the Mochizuki virus which was isolated in 1943 in Japan was shown to be close to Philippine 836-1 strain isolated in 1984 and Nauru Island strain isolated in 1974 at the respective places, in contrast with Thai AHF 82-80 strain isolated in 1980 and Caribbean CV1636/77 strain isolated in 1977. At the same time, a difference was noted between the Mochizuki and Philippine/Nauru strains at the cleavage site of preM/M junction: Mochizuki possessed RRGKR/S sequence whereas the Philippine/Nauru had RRDKR/S. The glycosylation site in preM and hydrophobic regions at the carboxyl termini of M and E were well conserved. Significances of the data are discussed in connection with viral epidemiology and variation.

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.