The release, degradation, and distribution of PVC microplastic-originated phthalate and non-phthalate plasticizers in sediments

This study investigated the leaching of phthalate and non-phthalate plasticizers from polyvinyl chloride microplastics (MPs) into sediment and their degradation over a 30-d period via abiotic and biotic processes. The results showed that 3579% of plasticizers were released into the sediment from the MPs and > 99.9% degradation was achieved. Although a significantly higher degradation was found in plasticizer-added microcosms under biotic processes (overall, 94%), there was a noticeable abiotic loss (72%), suggesting that abiotic processes also play a role in plasticizer degradation. Interestingly, when compared with the initial sediment-water partitioning for plasticizers, the partition constants for low-molecular-weight compounds decreased in both microcosms, whereas those for high-molecular-weight compounds increased after abiotic degradation. Furthermore, changes in the bacterial community, abundance of plasticizer-degrading bacterial populations, and functional gene profiles were assessed. In all the microcosms, a decrease in bacterial community diversity and a notable shift in bacterial composition were observed. The enriched potential plasticizer-degrading bacteria were Arthrobacter, Bacillus, Desulfovibrio, Desulfuromonas, Devosia, Gordonia, Mycobacterium, and Sphingomonas, among which Bacillus was recognized as the key plasticizer degrader. Overall, these findings shed light on the factors affecting plasticizer degradation, the microbial communities potentially involved in biodegradation, and the fate of plasticizers in the environment.

The passive sampler assisted human exposure risk characterization for tetrachloroethene soil vapor intrusion scenario

The potential human health risks associated with soil vapor intrusion and volatile organic compounds (VOCs) exposure were characterized at an industrialized site by the quantification of gaseous VOCs in soil pores using a passive sampling technique. The gaseous tetrachloroethene (PCE) in soil pores varied between 12 and 5,400 μg m-3 showing 3 orders of magnitude variation with dependence on groundwater PCE concentrations. Though the PCE concentration in the air only varied between 0.45 and 1.5 μg m-3 showing negligible variations compared to the variation observed in soil pores. The PCE concentration in the air varied between 0.45 and 1.5 μg m-3. The calculation of fugacity suggested that the PCE in the test site originated from groundwater. Measured PCE in groundwater ranged from 14 to 2,400 times higher than PCE in soil gas. This indicates that conducting a vapor intrusion risk assessment using passive soil gas sampling is critical for accurate risk characterization and assessment. Estimated PCE inhalation cancer risks for street cleaners and indoor residents varied between 10-6 and 10-4 with a low plausible hazard, and between 10-3 and 10-2 with a high risk, respectively. The results of this study demonstrate that passive sampling offers a significantly lower cost and labor-intensive approach compared to traditional methods for assessing pollution distribution in contaminated sites and characterizing risks. This highlights the potential for wider application of passive sampling techniques in environmental studies.

Determination of terpene levels after the use of essential oil diffusers in vehicles and studio apartments using passive sampling

The exposure levels of selected terpenes (limonene, α- and β-pinenes, and γ-terpinene) emitted by essential oil diffusers in vehicles and studio apartments were assessed using a passive sampling method. A previously developed passive sampler composed of an expanded polytetrafluoroethylene membrane and adsorbent (ePTFE PS) was enlarged and made wearable. Before field deployment, the sampling performance of the modified ePTFE PS for selected terpenes was compared with that of active sampling in a lab-scale 5 m³ test chamber under constant exposure conditions, supporting that passive sampling provides reasonable estimates of the time-weighted exposure concentration. Fifty volunteers were recruited and asked to wear the ePTFE PS while using an essential oil diffuser inside their own vehicle while commuting and in their studio apartment while sleeping. Terpene levels without an essential oil diffuser were very low in vehicles and 47, 3.6, 1.6, and 0.62 μg m^-3 for average concentrations of limonene, α- and β-pinenes, and γ-terpinene in studio apartments, respectively, close to those reported in previous studies. The indoor concentrations of all selected terpenes in vehicles and studio apartments were elevated by the use of essential oil diffusers, especially in vehicles. The average concentration of limonene in vehicles after the use of essential oil diffusers was 11 μg m^-3, which was greater than that before use by a factor of 30. Therefore, cautious usage of essential oil diffusers indoors where the volume is limited, such as a vehicle, is needed to reduce exposure to terpenes.

Development of an in situ equilibrium polydimethylsiloxane passive sampler for measuring volatile organic compounds in soil vapor

An equilibrium passive sampler made of polydimethylsiloxane (PDMS) fiber was developed to measure volatile organic compounds (VOCs) in soil vapor. Expanded polytetrafluoroethylene (ePTFE) was used to protect PDMS from pollution and direct contact with soil components. For all tested VOCs, equilibrium was reached after 7 days at 5 °C. The equilibrium partition coefficients of VOCs between PDMS, gas, and water were measured at three different temperatures. The analyte concentrations in PDMS exposed to gas and water separately were almost the same, which suggests that C_gas and C_water in soil pores can be accurately deduced from C_PDMS after equilibrium at various temperatures. To evaluate the passive sampler, active sampling measurements were performed simultaneously. Concentrations of VOCs deduced from the passive sampler were consistent with the concentrations measured by active sampling near the 1:1 line. Tests with artificial soils were conducted to observe the effects of soil components on passive sampling. The results suggest that the effect of water saturation can be ignored; in other words, the developed passive sampler can be applied in the vadose zone, which has fluctuating water saturation. With a holder for the sampler made of stainless steel, the developed in situ passive sampler can measure VOCs in contaminated soil vapor. The developed passive sampler was proven to be an alternative for measuring VOCs in soil vapor, which can be helpful for soil risk assessment and for observing the diffusion of VOCs in contaminated sites.

Determination of partition coefficients of phthalic acid esters between polydimethylsiloxane and water and its field application to surface waters

Phthalic acid esters (PAEs) or phthalates are endocrine-disrupting chemicals and among the most frequently detected hydrophobic organic pollutants, which can be gradually released from consumer products into the environment (e.g., water). This study measured the equilibrium partition coefficients for 10 selected PAEs, with a wide range of logarithms of the octanol-water partition coefficient (log K_ow) from 1.60 to 9.37, between poly(dimethylsiloxane) (PDMS) and water (K_PDMSw) using the kinetic permeation method. The desorption rate constant (k_d) and K_PDMSw for each PAEs were calculated from kinetic data. The experimental log K_PDMSw for the PAEs ranges from 0.8 to 5.9, which is linearly correlated with log K_ow values up to 8 from the literature (R² > 0.94); however, it slightly deviated for the PAEs with log K_ow values greater than 8. In addition, K_PDMSw decreased with the temperature and enthalpy for PAEs partitioning in PDMS-water in an exothermic manner. Furthermore, the effects of dissolved organic matter and ionic strength on the partitioning of PAEs in PDMS were investigated. PDMS was used as a passive sampler to determine the aqueous concentration of plasticizers in river surface water. The results of this study can be used to evaluate the bioavailability and risk of phthalates in real environmental samples.

Enrichment cultivation of VOC-degrading bacteria using diffusion bioreactor and development of bacterial-immobilized biochar for VOC bioremediation

Volatile organic compounds (VOCs) have been globally reported at various sites. Currently, limited literature is available on VOC bioremediation using bacterial-immobilized biochar (BC-B). In this study, multiple VOC-degrading bacteria were enriched and isolated using a newly designed diffusion bioreactor. The most effective VOC-degrading bacteria were then immobilized on rice husk-derived pristine biochar (BC) to develop BC-B. Finally, the performances of BC and BC-B for VOCs (benzene, toluene, xylene, and trichloroethane) bioremediation were evaluated by establishing batch microcosm experiments (Control, C; bioconsortium, BS; pristine biochar, BC; and bacterial-immobilized biochar, BC-B). The results revealed that the newly designed diffusion bioreactor effectively simulated native VOC-contaminated conditions, easing the isolation of 38 diverse ranges of VOC-degrading bacterial strains. Members of the genus Pseudomonas were isolated in the highest (26.33%). The most effective bacterial strain was Pseudomonas sp. DKR-23, followed by Rhodococcus sp. Korf-18, which degraded multiple VOCs in the range of 52-75%. The batch microcosm experiment data showed that BC-B remediated the highest >90% of various VOCs, which was comparatively higher than that of BC, BS, and C. In addition, compared with C, the BS, BC, and BC-B microcosms abundantly reduced the half-life of various VOCs, implying a beneficial impact on the degradation behavior of VOCs. Altogether, this study suggests that a diffusion bioreactor system can be used as a cultivation device for the isolation of a wide range of VOC-degrading bacterial strains, and a compatible combination of biochar and bacteria may be an attractive and promising approach for the sustainable bioremediation of multiple VOCs.

Profiling and assessing soil-air exchange of polycyclic aromatic hydrocarbons (PAHs) in playground dust and soil using ex situ equilibrium passive sampling

Cancer risk can be associated with exposure to polycyclic aromatic hydrocarbons (PAHs) in playground dust and soil. This study investigated the profiles and sources of PAHs from poured rubber-surfaced playground dust and uncovered playground surface soil, by applying an ex-situ equilibrium passive sampling technique. Surface dust and soil samples were collected from 15 different playgrounds in Seoul, Republic of Korea. The total 16 EPA PAHs concentrations in surface dust and soil varied from 198 to 919 μg kg^-1 dw and 68-169 μg kg^-1 dw, respectively. 4- to 6-ring PAHs were dominant, accounting for approximately 53.8%-94.5% of the total PAHs in surface dust and soil. The diagnostic ratios and principal component analysis suggested that a mixed coal combustion and vehicular emission was likely the main source of PAHs in the surface dust and soil. The higher total organic carbon content can explain the higher PAH accumulation and lower fugacities of PAHs. The fugacity comparison of phenanthrene and pyrene in dust, soil, air, and playground surface material indicated that atmospheric deposition is the main source of PAHs in the dust and soil on rubber-surfaced and uncovered surfaced playgrounds. This study contributes to the understanding of PAHs sources in dust and soil samples in children's playground and helps policymaker determine the right contamination sources for risk management.

Development of an expanded polytetrafluorethylene dosimeter for the passive sampling of volatile organic compounds in air

A passive sampler composed of a porous, hydrophobic, and gas-permeable expanded polytetrafluoroethylene (ePTFE) tube was developed to effectively concentrate volatile organic compounds (VOCs) in the air. The ePTFE dosimeter has larger sorbent mass normalized sampling rates (L h^-1) compared with literature. This result suggests that ePTFE dosimeter can effectively detect low level VOCs in less contaminated air, including indoors. The air boundary layer thickness can be neglected when the mass accumulated in sorbent is converted to gas phase VOCs concentrations. The vapor pressure dependent desorption of VOCs from the sorbent was observed and modeling results suggested that this could lead to the underestimation of VOCs concentrations in air. However, the determination of the appropriate sampling time and the consideration of desorption could overcome the underestimation. A proton transfer reaction quadrupole mass spectrometer and passive samplers were deployed simultaneously in a chamber under fluctuating VOCs concentrations in air. The time-weighted average concentrations of ethylbenzene were 0.016, 0.015, and 0.017 g m^-3 for 23, 46, and 69 min experimental period, respectively. The average concentration of the real-time analysis was 0.015 g m^-3 for 69 min. The results show the ePTFE dosimeter can be used to estimate time weighted VOCs concentrations in air.

Resilience of the sorption capacity of soil organic matter during drying-wetting cycle

The sorption capacity of soil organic matter (SOM) for hydrophobic organic chemicals (HOCs) is affected by various environmental factors, such as soil water saturation and drying. In this study, we used passive sampling to investigate the changes in the sorption capacity of SOM during a drying-wetting cycle using batch sorption experiments. Dried and non-dried peat mosses were used to observe the effect of the drying process on the sorption capacity of SOM at various levels of water saturation in soil pores. At soil with non-dried peat moss, the partition coefficient between the sampler and the soil (K_sampler/soil) slightly increased with decreasing water saturation. At soil with dried peat moss, however, there were almost no differences in the K_sampler/soil among different water saturations except for 100%. The soil organic carbon-water distribution coefficients (K_OC) for dried peat moss were consistently larger than those for non-dried peat moss at all water saturation levels. However, the K_OC values obtained at 100% water saturation for both non-dried and dried peat mosses differed only by 18-29%. For fluoranthene, there was only an 18% difference between the two K_OC values at 100% water saturation, whereas it was 91% at 10% water saturation. This finding suggests that wetting SOM returns mostly its sorption capacity for HOCs after the increase in K_OC caused by extreme drying. The range in sorption capacity obtained in this study showed the resilient margin of the sorption capacity of SOM for HOCs according to microclimatic changes that would occur constantly under environmental conditions.

National Reconnaissance Survey of Microplastics in Municipal Wastewater Treatment Plants in Korea

Large quantities of microplastics are thought to be emitted to freshwater environments via wastewater treatment plants (WWTPs). To evaluate the occurrence of microplastics in Korean WWTPs, a nationwide study was conducted for the first time in 50 representative WWTPs with large treatment capacities. Grab sampling and laboratory filtration were used for influents, whereas in situ filtration using a custom-made sampling device was used for effluents. The filtrates were pretreated using wet peroxidation and density separation prior to the identification of microplastics with a dissection microscope and Fourier-transform infrared spectroscopy. Pooled analyses of the microplastics revealed that they were predominantly fragment-shaped, and thermoplastics and synthetic fibers were the dominant microplastic materials in WWTPs. The concentration ranged from 10 to 470 L^-1 in influents and 0.004 to 0.51 L^-1 in effluents. The removal efficiency of microplastics during wastewater treatment was calculated to be 98.7-99.99% in 31 WWTPs. Additionally, WWTPs using advanced phosphorus removal processes exhibited higher removal efficiency than those not implementing such processes. Power-law distribution was successful in describing microplastic particle sizes down to 100 μm, although it was not applicable for smaller particles. This comprehensive monitoring study provides information on the current level and characteristics of microplastics in WWTPs in Korea.

Inhalation risk assessment of naphthalene emitted from deodorant balls in public toilets

The inhalation of naphthalene used as deodorant balls in public toilets could be an important cancer risk factor. The atmospheric concentration of naphthalene in public toilets (Cin) was estimated both by a polyurethane foam passive air sampler (PUF-PAS) deployed in nine public toilets in Seoul, Korea and by a steady-state indoor air quality model, including emission estimation using Monte-Carlo simulation. Based on the estimated Cin, cancer risk was also assessed for cleaning workers and the general population. The steady-state Cin estimated using the estimated emission rate, which assumed that air exchange was the only process by which naphthalene was removed, was much greater than the Cin value measured using PUF-PAS in nine public toilets, implying the importance of other removal processes, such as sorption to walls and the garments of visitors, as well as decreased emission rate owing to wetting of the naphthalene ball surface. The 95 percentile values of cancer risk for workers based on the estimation by PUF-PAS was 1.6×10-6 , whereas those for the general public were lower than 1×10-6 . The results suggested that naphthalene deodorant balls in public toilets may be an important cancer risk factor especially for the cleaning workers.

Comparative study of oxidative stress caused by anthracene and alkyl-anthracenes in Caenorhabditis elegans

Oxidative stress was evaluated for anthracene (Ant) and alkyl-Ants (9-methylanthracene [9-MA] and 9,10-dimethylanthracene [9,10-DMA]) in Caenorhabditis elegans to compare changes in toxicity due to the degree of alkylation. Worms were exposed at 1) the same external exposure concentration and 2) the maximum water-soluble concentration. Formation of reactive oxygen species, superoxide dismutase activity, total glutathione concentration, and lipid peroxidation were determined under constant exposure conditions using passive dosing. The expression of oxidative stress-related genes (daf-2, sir-2.1, daf-16, sod-1, sod-2, sod-3 and cytochrome 35A/C family genes) was also investigated to identify and compare changes in the genetic responses of C. elegans exposed to Ant and alkyl-Ant. At the same external concentration, 9,10-DMA induced the greatest oxidative stress, as evidenced by all indicators, except for lipid peroxidation, followed by 9-MA and Ant. Interestingly, 9,10-DMA led to greater oxidative stress than 9-MA and Ant when worms were exposed to the maximum water-soluble concentration, although the maximum water-soluble concentration of 9,10-DMA is the lowest. Increased oxidative stress by alkyl-Ants would be attributed to higher lipid-water partition coefficient and the π electron density in aromatic rings by alkyl substitution, although this supposition requires further confirmation.

Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons

Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K_sampler/soil) and the uptake rate constant (k_u) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K_sampler/soil and k_u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K_sampler/soil and k_u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations.

Influence of substrate conductivity on circulation reversal in evaporating drops

Nonuniform evaporation from sessile droplets induces radial convection within the drop, which produces the well-known "coffee-ring" effect. The evaporation also induces a gradient in temperature and consequently a gradient in surface tension, generating a Marangoni flow. Here we investigate theoretically and experimentally the thermal Marangoni flow and establish criteria to gauge its influence. An asymptotic analysis indicates that the direction of the flow depends on the relative thermal conductivities of the substrate and liquid, k_{R} identical withk_{S}/k_{L}, reversing direction at a critical contact angle over the range 1.45<k_{R}<2. We corroborate the theory experimentally and demonstrate that the Marangoni flow can significantly influence the resulting patterns of particle deposition.

Latency- and Defense-Related Ultrastructural Characteristics of Apple Fruit Tissues Infected with Botryosphaeria dothidea

ABSTRACT Apple fruit tissues infected with Botryosphaeria dothidea were examined by transmission electron microscopy using susceptible cv. Fuji and resistant cv. Jonathan. Immature (green) and mature (red) fruits of cv. Fuji with restricted or expanding lesions were also examined to reveal subcellular characteristics related with latent and restricted disease development. In infected susceptible mature fruits, cytoplasmic degeneration and organelle disruption commonly occurred, accompanying cell wall dissolution around invading hyphae. Cell wall dissolution around invading hyphae in subepidermis was rare in immature, red halo-symptomed cv. Fuji and resistant cv. Jonathan fruits. In infected immature fruits of cv. Fuji, presumably at the latent state of disease development, cellular degeneration was less severe, and invading hyphae contained prominent microbody-lipid globule complexes or the deposition of thin electron-dense outer layer around cell wall of intercellular hyphae. Both mature fruits with red halos and resistant apple fruits formed cell wall protuberances at the outside of cell walls. In addition, electron-dense extramural layers were formed in the resistant apple fruits. Aberrant hyphal structures such as intrahyphal hyphae were found only in resistant fruit tissues, indicating the physiologically altered fungal growth. These ultrastructural changes of host tissues and fungal hyphae may reflect the pathogenesis of apple white rot under varying conditions of apple fruits.

Reduction of aflatoxins by Korean soybean paste and its effect on cytotoxicity and reproductive toxicity--part 1. Inhibition of growth and aflatoxin production of Aspergillus parasiticus by Korean soybean paste (Doen-jang) and identification of the active component

The inhibitory effect of methanol extract of Korean soybean paste on the mold growth and aflatoxin production of a toxigenic strain of Aspergillus parasiticus ATCC 15517 was studied using different concentrations of the extract in yeast-extract sucrose broth. While inhibition in mold growth due to increasing the concentration of the extract was observed, the more remarkable effect was the inhibition of aflatoxin production. Reduction of mycelial weight as a result of addition of the extract was observed to range between 1.5 to 12.9% while reduction of aflatoxin production quantified by high-performance liquid chromatography ranged from 14.3 to 41.7%. Five percent of the extract significantly reduced aflatoxin production at the end of the incubation period (P < 0.05), although the effect on mycelial growth was less pronounced. This study indicates that soybean paste could also be an effective inhibitor of aflatoxin production even though mycelial growth may be permitted. The main active component identified by gas chromatography-mass spectroscopy was linoleic acid.

Isolated left main coronary ostial stenosis: intraoperative transesophageal echocardiography during surgical angioplasty

OBJECTIVE

We hypothesized that transesophageal echocardiography could be used to image the repair of a left ostium or main coronary artery following surgical angioplasty.

METHODS AND RESULTS

Six patients, all women, were found to have isolated left main coronary ostial stenosis. We performed preoperative transesophageal echocardiography (TEE) in three and intraoperative TEE in four of six patients. Their mean age was 48 years. They presented with severe angina (Class III or IV) with a short duration (6.8 +/- 7.8 months). They had a low incidence of risk factors while histopathologic examinations showed typical atherosclerosis in all four patients. Preoperative two-dimensional echocardiography demonstrated left main coronary ostial stenosis in three patients. We clearly observed the patency of the pericardial or saphenous venous patch with basal short-axis scan on two-dimensional and color Doppler echocardiography in all four patients after weaning them from cardiopulmonary bypass and finished operation without complications.

CONCLUSIONS

Our study shows that TEE can be used to image the repair of a left ostium or main coronary artery following surgical angioplasty and provide the surgeon with the required information about the adequacy of the repair.

A case of primary hepatic actinomycosis

Actinomycosis is a chronic suppurative and granulomatous disease characterized histologically by sulfur granules with extensive necrosis, fibrosis and sinus formation. Depending on the site of primary infection, actinomycosis is generally classified as cervicofacial, thoracic and abdominal type. The liver is known to be the primary site of infection in 15% with abdominal actinomycosis. The authors have experienced a case of liver abscess in a 24-year-old male. The sono-guided aspiration biopsy revealed findings of infiltration of neutrophils and characteristics sulfur granules by light microscopy. This case was thought to represent an instance of liver actinomycosis. Although there have been a lot of reports on actinomycosis of the liver in other countries, only 3 cases were reported in Korea.

Isolated left main coronary ostial stenosis in Oriental people: operative, histopathologic and clinical findings in six patients

OBJECTIVES

This study was performed to determine whether there are differences in the operative, histopathologic, angiographic and clinical findings of isolated ostial stenosis between Oriental and western patients.

BACKGROUND

Angiographic, clinical and histologic findings in isolated ostial stenosis have been reported in western but not in Oriental patients.

METHODS

Six patients, all women (0.88% of a total of 684 patients who underwent coronary angiography between March 1989 and July 1991), were found to have isolated left main coronary ostial stenosis. We performed surgical ostial angioplasty with the autologous pericardial or saphenous venous patch and biopsy at the aortic arteriotomy site in four of the six patients.

RESULTS

All six patients presented with severe angina (angina class III or IV) of short duration (mean +/- SD 6.2 +/- 6.2 months) and had a very low incidence of risk factors, although histopathologic examination showed typical atherosclerosis in four of the six patients. They were young to middle-aged women (mean 45 +/- 3 years) except for Patient 6 (62 years). Exercise duration was short and ST segment depression, accompanied by typical angina, was observed in many leads in the warm-up period or stage I. Despite the crucial location of the lesion, most patients had well preserved left ventricular function and normal wall motion. There was no angiographically definable collateral circulation from either ipsilateral or contralateral vessels except for grade I collateral circulation in Patient 5. Operative findings demonstrated mostly yellow atheroma in the aortic wall and left coronary ostium. Coronary angiography showed only ostial stenosis of the left coronary artery in all six patients, but operative findings documented atheromatous change in the left main coronary artery in two of the six.

CONCLUSIONS

The clinical, angiographic, histopathologic and operative findings of Oriental patients were similar to those reported in western patients, but the incidence of isolated left main coronary ostial stenosis was higher in the Oriental group. Angiographically definable isolated coronary ostial stenosis may often not be true isolated ostial stenosis.

[Prophylactic and therapeutic studies on intestinal giant-cystic disease of the Israel carp caused by Thelohanellus kitauei. I. Course of formation and vanishment of the cyst]

In an attempt to develop prophylactic and therapeutic measures of the intestinal giant-cystic disease caused by Thelohanellus kitauei in the Israel carp, Cyprinus carpio nudus, pathological observations were conducted upon the carps which were hatched in May 1988 and raised in a net cage fish farm at the Soyang lake, managed by Horim Fisheries for the period of 21 months with 1-2 months interval. After a gross inspection of the carps, necropsy was carried out periodically in order to clarify the pathological changes in various internal organs and muscular tissues. Also, the prevalence of the disease was checked during the period from 1988 to 1990. Gross inspections revealed that the infected carps showed some degree of fading in body and gill color, back-emaciation symptoms, reddish anus accompanying erosion and relaxation and pot-belly, as well as discharge of yellowish white mucoid material from the anus. However, most carps died eventually of intestinal obstruction. Other significant necropsy findings included cyst formation of various size in the intestinal mucosa, ascites, anemic condition through internal organs and muscular tissues, hyperemia and dilation of intestines with decreased tension, thinness and fragility, and full contents of semi-fluid or yellowish white mucoid material in the intestinal canals. Based on the morphological characteristics of the spores found in the cysts, parasitic location in the intestines, macro- and microscopic findings of the lesions, the parasites were identified as Thelohanellus kitauei Egusa et Nakajima, 1981. Although monthly changes of water temperature were distinct, the extrusion rates of the polar filaments of the spores stayed constant throughout the year with an exception of a lower rate in July. The lesions initiated from mucosa and submucosa in early July became large swellings and then complete mature forms following the peracute course. From late August the upper cysts were gradually opened and most of the spores were dispersed from anus into the surrounding water through December but only a few lasted until next April. The cysts were completely recovered until next September. Comparing the incidence and prevalence of the disease by year tremendous infection and death rates were checked in the first prevalent year, 1988, but the rates were significantly decreased in the second year, and showed an almost normal status in the third year, 1990. As the above summarized results showed, the disease entity might come to an end in three years after the first prevalent year, however, the spores must be strictly prevented because they could be infective in the water for one year.

[Increased primary success rate in coronary angioplasty using a guide wire with attached balloon (microprobe)]

In 15 cases of 350 consecutive coronary angioplasties conventional low profile balloon catheters did not traverse the stenosis or occlusion over the guide-wire. A balloon on a wire device ("Microprobe", 2 mm) passed the stenosis or occlusion easily with a good primary result in 14 cases. The angioplasty procedure could then be completed with a larger standard balloon catheter. Use of the balloon on a wire device expands the technical facilities of angioplasty and increases the primary success rate in technically difficult cases.