The impact of coronavirus disease 2019 (COVID-19) in Japanese companion animal clinics

The coronavirus disease 2019 (COVID-19) pandemic has had a tremendous impact on people's lives throughout the world. A cross-sectional study was conducted to clarify the influence of COVID-19 on Japanese companion animal clinics. A self-administered electronic questionnaire regarding the incidence of COVID-19, hygiene management, the influence on clinical service and employment, and mental stress of staff was conducted for workers in animal clinics between 1 May and 10 June 2021. Questions concerning the hygiene management before the occurrence of COVID-19, under the first state of emergency, and at the time of the survey were asked using the Likert scale. Kessler 6 (K6) was used as an indicator of mental distress. In total, 430 individuals responded. Of these, 4.9% experienced COVID-19 infection in staff. Hygiene management was strengthened, but no particular practice was statistically associated with the occurrence of COVID-19 cases in staff. In Nakaya's variation of Scheffe's paired comparison, the highest prioritized goal in the clinics was the prevention of nosocomial infection with COVID-19. The prevalence of serious mental illness (K6>=13) was 11.1% (95% confidence interval: 6.3-18.6%). Multivariable negative binomial regression found four risk factors for psychological distress: veterinary nurse (P=0.016 with veterinarians and P<0.01 with other staff), female (P=0.004), fear of infection at work (P<0.001), and stress by refraining from going out (P<0.001). Directors of clinics are recommended to take care of female veterinary nurses for distress.

Quantitative evaluation of the infection dynamics of bovine brucellosis in Tanzania

Brucellosis is endemic in Tanzania. A cross-sectional study was conducted at 17 cattle farms in agro-pastoral areas in Tanzania to identify risk factors associated with the within-farm prevalence of bovine brucellosis and to quantitatively assess the infection dynamics through disease modelling. Cattle blood sampling and interviews with farmers using a structured questionnaire were conducted. A total of 673 serum samples were screened using the Rose-Bengal plate test (RBPT), and sero-positivity of RBPT-positive samples was confirmed using a competitive enzyme-linked immunosorbent assay. Zero-inflated binomial regression was performed for univariable and multivariable risk factor analyses of within-farm prevalence. Several susceptible-infectious (SI) models were compared based on deviance information criteria, and age-dependent force of infection (FOI) was measured using age-specific prevalence data for the 10 infection-positive farms. Using the diagnoses of cows on the 17 farms, the basic reproduction number, R₀, was also calculated. The farm-level prevalence and animal-level adjusted prevalence were 58.8 % (10/17, 95 % confidence interval: 33.5-80.6 %) and 7.0 % (28/673, 95 % credible interval: 5.7-8.4 %), respectively. The risk factor for high within-farm prevalence was introduction of cattle from other herds. A mathematical model with constant FOI showed the annual probability of infection as 1.4 % (95 % credible interval: 1.0 %-2.0 %). The R₀ was 1.07. The constant FOI could have been due to the predominant mode of infection being transmission of Brucella from contaminated aborted materials during grazing. Direct purchase of infected cattle could facilitate efficient transmission between susceptible animals through abortion.

[Clinical utility of epidural anesthesia during and after major spine surgery]

BACKGROUND

Spine surgery causes severe postoperative pain, but epidural anesthesia is not commonly used. The main reason is that it might cause some complications, such as motor block and infection. We compared the efficacy of epidural infusion with hypodermic infusion.

METHODS

Thirty-two patients scheduled for spine surgery were included in the study. Patients were randomly assigned to receive either continuous epidural infusion (ropivacaine 0.18% and fentanyl 45.5 microg x ml(-1) at 2 ml x hr(-1)) or continuous hypodermic infusion via a patient-controlled analgesia system (morphine 0.04 mg x kg(-1) x ml(-1) at 0.5 ml x hr(-1); bolus: 0.5 ml x hr(-1)). We investigated pain and nausea by using visual analogue scale after surgery.

RESULTS

Patient data did not differ between groups. Pain and nausea scores were significantly lower in the epidural infusion group than in the hypodermic infusion group. Epidural infusion did not cause any complications. The incidence of nausea in the hypodermic infusion group was 13 times as high as that in the epidural infusion group. Similarly, the incidence of nausea in female patients was 13 times as high as that in male patients.

CONCLUSIONS

Continuous epidural infusion provides superior analgesia even if high-dose local anesthetics are not used. Besides, it decreases the incidence of nausea because systemic administration of opioids can be avoided.

Enhancement of oxygen transfer efficiency in diffused aeration systems using liquid-film-forming apparatus

Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, liquid-film-forming apparatus is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for liquid-film-forming apparatus alone is found to be as much as 5.3 times higher than that for water surface and that the total volumetric mass transfer coefficient for liquid film aeration system increases by 37 % in comparison with conventional aeration system. Additionally, by tuning finely the structural parameters of the liquid-film-forming apparatus, it can also lead to high dissolved oxygen water with the dissolved oxygen percent saturation greater than 90 %. More importantly, this result is accomplished by simply offering a single-pass aeration at the depth as shallow as 26 cm. As a result, the objective of economical energy consumption in diffused aeration systems can be realized by lowering the aeration depth without sacrificing the aeration efficiency.

Improvement of oxygen transfer efficiency in aerated ponds using liquid-film-assisted approach

In aerated ponds, oxygen is generally supplied through either diffused or mechanical aeration means. Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, a liquid-film-forming apparatus (LFFA) is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for LFFA alone is found to be as much as 5.3 times higher than that for water surface and that the total volumetric mass transfer coefficient for the liquid film aeration system increases by 37% in comparison with a conventional aeration system. Additionally, by tuning finely the structural parameters of the LFFA, it can also lead to high dissolved oxygen (DO) water with the DO percent saturation greater than 90%. More importantly, this result is accomplished by simply offering a single-pass aeration at a depth as shallow as 26 cm. As a result, the objective of economical energy consumption in aerated ponds can be realized by lowering the aeration depth without sacrificing the aeration efficiency. It is noteworthy that the data presented in this study are acquired either numerically or experimentally.

Resource recovery from excess sludge by subcritical water combined with magnesium ammonium phosphate process

The amount of excess sludge produced in municipal wastewater treatment plants in Japan is increasing every year as the urban population increases. Phosphorus in excess sludge could be a potential phosphorus resource since at present, phosphate rock is being exhausted all over the world. Every year, Japan imports large quantities of phosphorus from abroad but much is discharged as excess sludge. Therefore, the solubilization process, one method of recovering phosphorus from sludge, could be a promising solution. In this study, a subcritical water process, a new technology that solubilizes sludge under subcritical conditions, was applied before the phosphorus in sludge was recovered with the magnesium ammonium phosphate (MAP) process. As a result, the solubilization rate of excess sludge achieved approximately 80% and about 94-97% of the phosphorus could be recovered.

Screening Thermotolerant White-Rot Fungi for Decolorization of Wastewaters

To select a thermotolerant fungal strain for decolorization of wastewaters, ligninolytic enzyme production (lignin peroxidase, manganese peroxidase [MnP], and laccase), decolorization, and removal of total phenol and chemical oxygen demand (COD) were detected. Thirty-eight fungal strains were studied for enzyme production at 35 and 43 degrees C on modified Kirk agar medium including 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and MnCl2. Thirteen strains grew on manganese-containing agar and provided green color on ABTS-containing agar plates under culture at 43 degrees C. Decolorization of wastewater from alcohol distillery (WAD) by these strains was compared under static culture at 43 degrees C, and Pycnoporus coccineus FPF 97091303 showed the highest potential. Thereafter, immobilized mycelia were compared with free mycelia for WAD decolorization under culture conditions of 43 degrees C and 100 rpm. The immobilized mycelia on polyurethane foam enhanced the ligninolytic enzyme production as well as total phenol and color removal. At about the same COD removal, MnP and laccase produced by immobilized mycelia were 2 and 19 times higher than by free mycelia; the simultaneous total phenol and color removal were 3.1 and 1.5 times higher than the latter. Moreover, decolorization of synthesis dye wastewater was carried out at 43 degrees C and 100 rpm. More than 80% of 300 mg/L of reactive blue-5 was decolorized by the immobilized mycelia within 1 to 2 d for four cycles.

Study on the potential of farmland soils as non-point sources of nitrogen and phosphorus in Japan

The amounts of N and P accumulated in farmland soils of 50 cm depth were equivalent to the amount of chemical fertilizer supplied for 50-70 years. The values of N/P of surface soils in farmlands were 1.0-4.3, lower than expected. The median diameter of soil particles in run-off waters was generally less than 10 microm. The mean values of particulate fractions over 1 microm and over 0.22 microm were 19% for N, 27% for P, and 39% for N, 64% for P respectively. Fine particles of soil containing concentrated phosphorus should be carefully monitored as potential sources related to eutrophication.

On-site treatment of turbid river water using chitosan, a natural organic polymer coagulant

Chitosan, acetylate of chitin, is a biodegradable cationic polymer. The objective of this study is to assess the applicability of chitosan as an on-site treatment agent of turbid water caused by river construction works and other diffused pollutions. The results of jar-tests indicate that floc of chitosan is much larger than that of aluminium sulfate, and turbidity treated by chitosan under moving water conditions is much lower than that of aluminium sulfate. Chitosan is applied to Imou River in Yamaguchi prefecture, where river construction work is going on. St.1 is located just below the construction work, St.2 is located about 250 m downstream from St.1, and St.3 is located about 350 m downstream from St.2. Initial turbidity of each station is 1,100, 937 and 313 NTU, respectively. By applying chitosan at St.1, turbidity of each station is drastically reduced to 1,100, 12 and 0 NTU. Chitosan could be helpful to reduce problems caused by turbidity in rivers.

Recycling mineral nutrients to farmland via compost application

Increased cultivation of farmland has resulted in nutrient deficiency and consequently fertility degradation of soils. This research examined the application of composted wastes in terms of the feasibility and effectiveness of recycling plant essential minerals. Minerals in composts (derived from sewage sludge, livestock excrement, and municipal solid wastes, respectively) and in amended soils were observed. Ca/Mg ratios in amended soils and the effect of compost applications (mineral nutrients and heavy metals) on plant uptake were also studied. Results showed that composts, especially those made from sewage sludge and livestock excrement, were richer in mineral nutrients but also contained more heavy metals than untreated soil. The increase in some elements and plant-growth-essential Ca/Mg ratios were found in amended farmlands, implying that compost applications have made up for the nutrient deficiency and have adjusted chemical conditions of the soil. The soil contamination from heavy metals was noticeable. However, some results showed that the large existence of mineral nutrients and heavy metals in soils has caused no significant increase in the plant uptake of elements. The controlled composting process and farmland uses are believed necessary for reducing the heavy metal accumulation in agricultural plants.

Decolorization of alcohol distillery wastewater by thermotolerant white-rot fungi

To detect thermotolerant fungus strain for decolorization of alcohol distillery wastewater (WAD), 38 fungus strains were studied. Ability of ligninolytic enzyme production was examined at 35 and 43 degrees C on agar media containing 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) and MnCl2. At 43 degrees C, four of Pycnoporus coccineus strains showed their higher potential for WAD decolorization both on agar media and in liquid media. Immobilized mycelia on polyurethane foam removed total phenol about threefold higher than free mycelia did in shaking condition at 43 degrees C. Moreover, color removed by immobilized mycelia nearly 50% higher than free mycelia did.

Compost stability assessment using a secondary metabolite: geosmin

Composting is a process involved not only in transformation of organic matter (OM), but also for transition of the microbial community. Microorganisms can directly provide important information on the stages and characteristics of composting. This paper was aimed at characterizing compost stability by a microbial secondary metabolite, geosmin, which is a volatile compound presenting an earthy smell. Since secondary metabolite production is dependent on the nutrient state of microorganisms, its production in association with physical and chemical parameters was monitored in the laboratory-scale and plant-scale composting processes. The results showed that the peaked geosmin liberation was consistent with stable state of composting indicated by the ambient temperature achieved, a slightly alkaline product and steady states of dissolved organic carbon (DOC), N and P contents and OM degradation in the laboratory-scale experiment. It was also in accordance with the stability identified by the facilities and CO2 respiration rate in the plant-scale composting. In addition, the production of geosmin was correlated with the C/N ratio for the solid sample. These results demonstrated that geosmin levels could be used as an index for the compost stability assessment in different composting processes with various organic solid wastes.

Distributions of iron, manganese, copper and zinc in various composts and amended soils

A detailed observation was conducted on Fe, Mn, Cu and Zn in the composts derived from seafood processing by-product, garbage, swine manure and sewage sludge, respectively, as well as in amended farmlands. All elements were at lower levels of total contents but a higher percentage of water-soluble and exchangeable forms in composted seafood processing by-product and composted garbage than in composted swine manure and composted sewage sludge. Total contents increased in the order: composted seafood processing by-product approximately composted garbage < composted swine manure < composted sewage sludge. The applications of composted seafood processing by-product and composted garbage have neither caused Fe, Mn, Cu and Zn accumulation nor changed their distribution in soils; while the application of composted swine manure has largely increased Cu and Zn contents in soils, mainly in organic matter-bound form, and that of composted sewage sludge increased Mn, Cu and Zn in soils mainly in carbonate-bond and Fe-Mn oxides-bound ones. Fe is an exception, its total contents in soils decreased with the applications of composts except for composted garbage. Also, the rainfall and irrigation were another two main factors that affected available elements in soils.

Modeling prediction of membrane bioreactor process with the concept of soluble microbial product

The existence of soluble microbial products (SMP) produced by microbial cultures involved in biological wastewater treatment process has been widely investigated. This paper aims to establish an available mathematical model by incorporating the SMP concept into the Activated Sludge Model (ASM) No. 3. Prediction of sewage treatment performance in membrane bioreactor process under intermittent aerobic condition by model simulation was presented, and the results provided a more comprehensive image for this process. It was found that SMP could not be ignored and it contributed about 15% of total COD in the reactor under HRT = 12 hr and SRT = 10 days condition. The model also provided reasonable simulation results for nitrogen, biomass concentration, and other treatment behaviors. Furthermore, the treatment performance can be predicted under various operating conditions by this proposed model.

Monitoring of shallow sea environment by using snapping shrimps

We examine the validity of pulse count of snapping shrimps for sea environmental monitoring. Snapping shrimps, which make a peculiar pulse sound, are found everywhere in the world. Pulse count can be achieved merely by recording their sounds for a few minutes by using a hydrophone without special biological knowledge. From field surveys and laboratory experiments, we found that the pulse count depends on water temperature when sea environment is normal, and it falls due to the occurrence of oxygen-deficient water. The results show that this method can be a useful index of the effect of water pollution on benthic animals in fixed-point observation.

Present state of food and feed cycle and accompanying issues around Japan

Nitrogen (N) and phosphorus (P) cycles of food and feed, and the regulation systems for industrial wastewater are studied. The rate of domestic supply of food in Japan is 41% in 1970, 32% in 1990, and 29% in 1998 for N and 33%, 29%, and 28% for P, excluding grass feed. Among 3 countries, Japan, USA and Thailand, Japan is in the most difficult state to recycle food wastes to farmland. Comparing the estimated load of wastewater from food processing industries with the estimated load according to the budget study for N and P cycles, the tentative criteria of wastewater of food processing for P seem to be loose, and denitrification might be considered in every stage of N cycles. New regulation of industrial wastewater recently proposed in Japan may induce the chance for environmental business to remove N and P.

Effect of enforced aeration on in-vessel food waste composting

A laboratory composting was conducted to determine the effect of the continuously enforced aeration on the composting performance. The mixture of dog food, excess sludge, and woodchip was used as raw composting materials. The temperature changes in the decomposition process, and pH, weight loss, ash, and extract composition from the final product after 17 days composting were investigated. The results demonstrated that flow rate of enforced aeration indeed influenced the composting performance. Composting under 0.05-0.1 1 min(-1) condition seemed better than that under 0.2-0.41 min(-1) condition. Higher flow rate of air not only cooled the composting mixture significantly, further adversely affected temperature rise, but also evaporated moisture mostly. Thermophilic composting can occur under 0.05-0.11 min(-1) air flow rate condition, while composting in cases of 0.2-0.4 l min(-1) air flow rate mainly resulted in a mesophilic process. Microbial activity was considered to be significantly inhibited at 0.4 1 min(-1) air flow rate condition based on the analyses of total organic carbon and volatile fatty acids from water extraction of composting products.

A model for membrane bioreactor process based on the concept of formation and degradation of soluble microbial products

A mathematical model of soluble microbial products (SMPs) formation-degradation was established based on the activated sludge model no. 1 and was applied to the membrane bioreactor process with high concentration of activated sludge under intermittent aerobic operational condition. The simulation results were in good agreement with the experimental data which indicated that the coefficients used in the model could successfully describe the treatment performance. The most advantage of this modified model over the conventional one was that the significant importance of SMP existence was demonstrated and the model provided an reasonable comprehension for SMP concept. The present study demonstrated that SMPs contributed most to the organic matter in the effluent, and the results coincided well with the observations of many other researchers.

A pilot-scale study of tertiary treatment of Jizhuangzi wastewater treatment plant by continuous preozonation-microflocculation-filtration process

A pilot-scale study of tertiary wastewater treatment of the JIZHUANGZI Municipal Wastewater Treatment Plant was carried out by preozonation, coagulation and direct filtration process with the aim of producing wastewater suitable for reuse. The proposed treatment scheme could produce a filtered water with lower turbidity, COD(Cr) and colour at lower ozone and coagulant dosages. Ozone was added into the mixing tank with coagulant simultaneously and postozonation was not cost effective. With the increase of ozone dosage, better COD(Cr) and colour removals were observed especially at the ozone dosage between 0.7-1.0 mg l(-1). Similarly, increasing ferric sulphate dosage resulted in better removals of turbidity, COD(Cr) and colour in the filtered water. In contrast, increasing polymer T-80 dosage seemed to improve colour removal rather than turbidity and COD(Cr). To achieve removal efficiency of 70% for turbidity, 45% for COD(Cr) and over 60% for colour, the optimum dosages of ozone, ferric sulphate and polymer T-80 should be 0.7-1.0 mg l(-1), 10.0-12.5 mg l(-1) and 0.7-1.0 mg l(-1), respectively.

The entire nucleotide sequences of two distinct TT virus (TTV) isolates (TJN01 and TJN02) remotely related to the original TTV isolates

TT virus (TTV) has a wide range of sequence divergence by which it is classified into at least 16 genotypes. A TTV isolate of genotype 12 (TJNO1) and another of genotype 13 (TJN02) were sequenced in the entire genome, and compared with the reported TTV isolates. TJN01 and TJN02 had genomic lengths of 3787 and 3794 nucleotides (nt), respectively, which were shorter by 66 and 59 nt than the prototype TTV isolate of genotype 1 (TA278). TJN01 and TJN02 shared the nucleotide sequence with TA278 merely in 53.9% and 55.2%, respectively. They possessed two major open reading frames (ORFs) and the noncoding region with a GC-rich region forming stem-loop structures, which are characteristic of TTV. However, their amino acid sequences in ORF1 were similar to that of TA278 in only 35.4 and 34.0%, respectively; TJN01 was 45.4% similar to TJN02. Comparison with TTV isolates of the same genotype identified hypervariable regions in ORF1 of TJN01 and TJN02, as in the prototype TTV of genotype 1. However, quasispecies were barely observed in them. Furthermore, sequences of hypervariable regions scarcely changed during 2-5.5 years in both TJN01 and TJN02. These results indicate that TTV of genotypes 12 and 13 are much different from the prototype TTV of genotype 1.

Circular double-stranded forms of TT virus DNA in the liver

TT virus (TTV) is an unenveloped, circular, and single-stranded DNA virus commonly infecting human beings worldwide. TTV DNAs in paired serum and liver tissues from three viremic individuals were separated by gel electrophoresis and characterized biophysically. TTV DNAs in sera migrated in sizes ranging from 2.0 to 2.5 kb. TTV DNAs in liver tissues, however, migrated at 2.0 to 2.5 kb as well as at 3.5 to 6.1 kb. Both faster- and slower-migrating forms of TTV DNAs in the liver were found to be circular and of the full genomic length of 3.8 kb. TTV DNAs migrating at 2.0 to 2.5 kb, from either serum or liver tissues, were sensitive to S1 nuclease but resistant to restriction endonucleases, and therefore, they were single-stranded. By contrast, TTV DNAs in liver tissues that migrated at 3.5 to 6.1 kb were resistant to S1 nuclease. They migrated at 3.7 to 4.0 kb after digestion with EcoRI, which suggests that they represent circular, double-stranded replicative intermediates of TTV. When TTV DNAs were subjected to strand-specific primer extension and then amplified by PCR with internal primers, those in serum were found to be minus-stranded DNAs while those in liver tissues were found to be a mixture of plus- and minus-stranded DNAs. These results suggest that TTV replicates in the liver via a circular double-stranded DNA.

Significance of egg-jelly substances in the internal fertilization of the newt, Cynops pyrrhogaster

Japanese newt, Cynops pyrrhogaster, undergoes internal fertilization as do most urodeles. In this study, we focused on the roles of egg-jelly in fertilization of C. pyrrhogaster and characterized the substances associated with those roles. When dry sperm were directly inseminated onto the egg, normal fertilization occurred without the presence of water. Egg-jelly extract (JE) prepared with Steinberg's salt solution contained the activity for the initiation of sperm motility. A substance of about 50 kDa in JE was significant for this activity; an inactive form of the substance probably exists in JE. Strong activity to induce acrosome reaction was detected in JE. It was inhibited by the treatment of JE with WGA, suggesting that carbohydrate in JE may be important for the induction of the acrosome reaction. This study suggests that two significant processes of fertilization are regulated by substances in the egg-jelly of the newt, C. pyrrhogaster.

Fact-finding survey of actual garbage discharged from dormitory and its biological anaerobic-aerobic treatment

The objective of this study is to find a possibility of complete treatment of garbage and resource recovery (production of methane from available utility of carbon resource in garbage) by biological treatment process. As the first step, a fact-finding survey of actual garbage discharged from the dormitory of the Ube National College of Technology (equivalent to 300 population) was carried out. Second, the combined biological anaerobic-aerobic treatment, i.e. combination of upflow anaerobic sludge blanket (UASB) process and aerobic membrane bioreactor (AMB) process, was applied to the garbage treatment. The applicability and efficiency of this system were investigated in this study. The survey results showed that the composition and quantity of garbage from a student dormitory changed slightly during a week due to the change of the menu, however, they remained almost unchanged during the entire experimental period. The experimental results showed high biodegradability of the garbage, and demonstrated its suitability for methane production. The soluble nitrogen removal was high: over 97%. No excess sludge was wasted from the system. A high treatment efficiency of simultaneous organic carbon and nitrogen was obtained. The possibility of complete treatment of garbage with this process has been positively demonstrated by this study.

Quasispecies of TT virus (TTV) with sequence divergence in hypervariable regions of the capsid protein in chronic TTV infection

Three hypervariable regions were identified in a central portion of open reading frame 1 of TT virus DNA, which codes for a putative capsid protein of 770 amino acids. TT virus circulates as quasispecies, with many amino acid substitutions in hypervariable regions, to evade immune surveillance of the hosts and to establish a persistent infection.

A novel unenveloped DNA virus (TT virus) associated with acute and chronic non-A to G hepatitis

In 1997, a novel DNA virus was isolated from the serum of a patient with posttransfusion hepatitis of unknown etiology in Japan, and it was named TT virus (TTV) after the initials of the index patient. TTV is a nonenveloped, single-stranded and circular DNA virus, and its entire sequence of approximately 3.9 kb has been determined. For being a DNA virus, TTV has a wide range of sequence divergence, allowing the classification into at least 16 genotypes separated by a sequence difference of >30% from one another. The nucleotide sequence of the noncoding region of the TTV genome is conserved, whereas that of the coding region is highly variable. TTV strains with extremely high sequence divergence are common in the same individuals, thereby indicating a mixed infection of TTV strains of different genotypes. An association is found between hepatitis of unknown etiology and the TTV genotypes which are detectable by PCR with primers deduced from the N22 region (genotype 1) in the open reading frame 1 encoding the capsid protein. It would be important to select the primers for specific detection of the TTV genotypes associated with clinical diseases, to further evaluate the capacity of TTV to induce acute and chronic liver disease as well as extrahepatic manifestations.

Effect of interferon on a nonenveloped DNA virus (TT virus) associated with acute and chronic hepatitis of unknown etiology

An unenveloped DNA virus named TT virus (TTV) has been reported in association with acute and chronic hepatitis of unknown etiology. The effect of interferon on TTV was evaluated in the patients with chronic hepatitis C who were coinfected with TTV. TTV DNA was determined by a polymerase chain reaction with heminested primers in the 96 patients with chronic hepatitis C who received interferon-alpha (516 million units in 26 weeks) and followed for 24 months thereafter. TTV DNA was detected in 31 (32%) patients before therapy. TTV DNA became undetectable during interferon therapy and remained absent in 14 (45% of the 31 patients) through 24 months thereafter. The four patients with pretreatment TTV DNA titer > or =10(3)/ml did not respond. These results indicate that TTV is sensitive to interferon, and the response would be inversely correlated with pretreatment viral titers.

The entire nucleotide sequence of a TT virus isolate from the United States (TUS01): comparison with reported isolates and phylogenetic analysis

A nonenveloped and single-stranded DNA virus designated TT virus (TTV) has been reported from Japan in association with hepatitis of unknown etiology. Very recently, the prototype TTV isolate (TA278) of genotype 1 is proven to have a circular genome with 3852 nucleotides. A TTV isolate (TUS01) was recovered from a blood donor in the United States, and its entire circular nucleotide sequence of 3818 nucleotides was determined. It possessed two open reading frames coding for 761 and 156 amino acids, respectively. TUS01 shared 60.5% of the nucleotide sequence with the TA278 isolate from Japan that was longer by 35 nt. The sequence of the noncoding region of 1203 nt was conserved with a similarity of 83.4%. Sequence preservation was much lower for the two open reading frames; nucleotide and amino acid sequences were 54.8 and 37.0% similar, respectively, for one and 55.5 and 38.8% similar for the other. By comparison of a partial sequence of 222 nucleotides among 239 TTV isolates available from various countries, at least 11 genotypes with sequence divergence of >30% were recognized. TUS01 was deduced to be of genotype 11, which has not been reported before. Conserved sequences in the noncoding region could be used as primers for sensitively detecting TTV DNA by polymerase chain reaction. Divergent sequences in coding regions would be useful as primers for distinguishing various TTV genotypes.

Marked genomic heterogeneity and frequent mixed infection of TT virus demonstrated by PCR with primers from coding and noncoding regions

A nonenveloped, single-stranded, and circular DNA virus designated TT virus (TTV) has been reported in association with hepatitis of unknown etiology. TTV has a wide sequence divergence (approximately 52%), by which it is classified into at least 16 genotypes separated by an evolutionary distance of >0.30. Therefore, the detection of TTV DNA by polymerase chain reaction would be influenced by primers deduced from conserved or divergent regions of the genome. Of the 30 sera from healthy individuals, up to 17% tested positive with primers deduced from coding region, much less frequently than up to 93% testing positive with primers from noncoding region. These differences were not attributable to the sensitivity of detection, because a cloned TTV DNA of genotype 1a was detected sensitively (up to 1 copy per test) with primers deduced from either the coding or the noncoding region of the same genotype. Sera testing positive only with noncoding region primers, or those showing higher titers with noncoding than coding region primers, contained TTV DNA strains with sequence divergence of 47-53% from the TA278 isolate of genotype 1a within the N22 region spanning 222-231 nucleotides. Some of the sera contained two or three TTV DNA strains of distinct genotypes. These results indicate TTV strains with extremely high sequence divergence prevailing in healthy individuals and frequent mixed infection with TTV strains of distinct genotypes.

Effect of interferon on a nonenveloped DNA virus (TT virus) associated with acute and chronic hepatitis of unknown etiology

An unenveloped DNA virus named TT virus (TTV) has been reported in association with acute and chronic hepatitis of unknown etiology. The effect of interferon on TTV was evaluated in the patients with chronic hepatitis C who were coinfected with TTV. TTV DNA was determined by a polymerase chain reaction with heminested primers in the 96 patients with chronic hepatitis C who received interferon-alpha (516 million units in 26 weeks) and followed for 24 months thereafter. TTV DNA was detected in 31 (32%) patients before therapy. TTV DNA became undetectable during interferon therapy and remained absent in 14 (45% of the 31 patients) through 24 months thereafter. The four patients with pretreatment TTV DNA titer > or =10(3)/ml did not respond. These results indicate that TTV is sensitive to interferon, and the response would be inversely correlated with pretreatment viral titers.

Excretion into bile of a novel unenveloped DNA virus (TT virus) associated with acute and chronic non-A-G hepatitis

Recently, an unenveloped, single-stranded DNA virus named TT virus (TTV) has been reported in association with hepatitis of non-A-G etiology. Five patients with TTV viremia, who received bile drainage or cholecystectomy, were tested for TTV DNA in bile by polymerase chain reaction with heminested primers. TTV DNA was detected in bile from all patients; titers were 10-100 times higher than in serum in 4 and at a comparable level in the remaining 1 patient. TTV DNA was detected in feces, also, in 1 of the 2 patients tested. The buoyant density of TTV in bile from 1 tested patient (1.33-1.35 g/cm3) was the same as that in feces (1.32-1.35 g/cm3). TTV may be secreted via bile into feces in a transmissible form and would spread by a fecal-oral route for deep and wide penetration into the general population.

Infection by an unenveloped DNA virus associated with non-A to -G hepatitis in Japanese blood donors with or without elevated ALT levels

BACKGROUND

An unenveloped, single-stranded DNA virus named TT virus has been found in association with elevated alanine aminotransferase (ALT) levels in recipients of transfusions and has been detected frequently in patients with acute or chronic hepatitis of non-A to -G etiology in Japan. DNA of the TT virus was searched for in blood donors with or without elevated ALT levels.

STUDY DESIGN AND METHODS

A total of 861 blood donors without previous transfusions and who were negative for markers of hepatitis B or C virus infection were tested. DNA of the TT virus was detected by polymerize chain reaction with hemi-nested primers.

RESULTS

TT virus DNA was detected in 62 of 280 (22.1% [95% CI: 18.1-26.6]) donors with elevated ALT levels (mean +/- SD, 89.3 +/- 36.4 U/L; range, 61-301 U/L), which is significantly more frequently (p<0.02) than its detection in 91 of 581 (15.7% [95% CI: 13.2-18.4]) donors with normal ALT (< or = 45 U/L). The frequency of TT virus DNA increased with age, in donors with and without elevated ALT.

CONCLUSION

The detection of TT virus DNA, at a frequency higher in donors with elevated ALT than in those without, strengthens the association of TT virus with non-A to -G hepatitis.

Determination of antibodies to TT virus (TTV) and application to blood donors and patients with post-transfusion non-A to G hepatitis in Japan

Recently, a nonenveloped single-stranded DNA virus named TT virus (TTV) has been reported in association with non-A to G post-transfusion as well as sporadic acute and chronic liver disease. A method was developed for the detection of antibody to TTV (anti-TTV) by means of immune precipitation and detection of TTV DNA by the polymerase chain reaction. The test serum was incubated with TTV, recovered from feces of a carrier, and after incubation, the formed immune complexes were precipitated with goat antiserum to human IgG. TTV DNA was sought for by the polymerase chain reaction in both precipitate and supernatant. The detection of TTV DNA in the precipitate, but not in the supernatant, was considered to represent anti-TTV in the test serum. Of the 44 healthy blood donors in Japan, anti-TTV was detected in one of the six (17%) with TTV DNA and 11 of the 38 (29%) without TTV DNA. In the two patients with post-transfusion non-A to G hepatitis, free anti-TTV developed as they cleared TTV in serum. Anti-TTV complexed with TTV in serum, detectable by precipitating sera with goat anti-human IgG and testing for TTV DNA, elicited while the patients had elevated alanine transaminase levels. The determination of anti-TTV would be useful for detecting resolved infection in surveys for exposure to TTV in the general population, and for establishing the mechanism of liver injury associated with TTV infection.

Fecal excretion of a nonenveloped DNA virus (TTV) associated with posttransfusion non-A-G hepatitis

Five patients with type B or C hepatocellular carcinoma were found to be infected with a nonenveloped DNA virus (TTV) associated with posttransfusion hepatitis of non-A-G etiology. Paired feces and serum samples from these patients were tested for TTV DNA by polymerase chain reaction with seminested primers and their sequences were compared. TTV DNA was detected in sera from all of the patients, while it was detected in feces from three patients, including two with high viral titers in serum. When feces and serum from one patient were subjected to floatation ultracentrifugation in CsCl, TTV in feces banded at a peak density of 1.35 g/cm3 and that in serum at 1.31-1.32 g/cm3. TTV isolates in three pairs of feces and serum had the identical sequence of 222 base pairs. The excretion of TTV into feces indicates that TTV would be transmitted not only parenterally but also nonparenterally by a fecal-oral route.

Fecal excretion of a nonenveloped DNA virus (TTV) associated with posttransfusion non-A-G hepatitis

Five patients with type B or C hepatocellular carcinoma were found to be infected with a nonenveloped DNA virus (TTV) associated with posttransfusion hepatitis of non-A-G etiology. Paired feces and serum samples from these patients were tested for TTV DNA by polymerase chain reaction with seminested primers and their sequences were compared. TTV DNA was detected in sera from all of the patients, while it was detected in feces from three patients, including two with high viral titers in serum. When feces and serum from one patient were subjected to floatation ultracentrifugation in CsCl, TTV in feces banded at a peak density of 1.35 g/cm3 and that in serum at 1.31-1.32 g/cm3. TTV isolates in three pairs of feces and serum had the identical sequence of 222 base pairs. The excretion of TTV into feces indicates that TTV would be transmitted not only parenterally but also nonparenterally by a fecal-oral route.

Spontaneous healing of pancreatic abscess after fistulization to the duodenal bulb

A 70-year-old man was admitted to the hospital because of sudden, upper abdominal and back pain. Laboratory and image data indicated acute pancreatitis. Shortly after the admission, pancreatic and liver abscess with bacteremia developed. Antibiotic therapy seemed effective. A month later, spontaneous fistulization of the pancreatic abscess to the duodenal bulb was found by gastroduodenal fiberscopy. Injection of contrast medium into the duodenal orifice showed that the fistula was draining the abscess and that no other fistula formed from the abscess. Endoscopic retrograde cholangiopancreatogram indicated no fistula formation to the pancreatic duct. The pancreatic abscess became smaller and was not visible using computerized tomography and ultrasonography 3 months later and thereafter. Closure of the duodenal orifice was ascertained by the endoscopy. It is suggested that retrograde infection from the fistula was prevented by the single fistulization to the acidic duodenal bulb, which is not supposed to allow most bacterial growth. Pancreatic abscess usually necessitates operative treatment, even with fistulization to the alimentary tract. It seems likely that the single, small fistulization to the bulb, in addition to the lack of underlying disease and medical and nutritional support, facilitated the spontaneous healing process.

Struma ovarii: MR findings

PURPOSE

The purpose of this study was to determine the MR appearance of struma ovarii correlating with the pathological features.

METHOD

MR findings of two patients with struma ovarii were retrospectively reviewed and compared with the pathological findings.

RESULTS

Both tumors were complex masses composed of multiple cysts and solid components. The size and signal intensity of multiple cysts varied within the tumor. Hyperintense cystic areas on T1-weighted images were thought to correspond pathologically to hemorrhagic cysts and follicles containing viscous proteinaceous colloid. Solid components had as high a signal intensity as did uterine endometrium on T2-weighted images and as intermediate a signal intensity as did uterine muscle layer on T1-weighted images. After intravenous administration of gadolinium-DTPA, the solid components showed marked contrast enhancement. There was also ascitic fluid associated with adhesion and peritoneal thickening.

CONCLUSION

The characteristic MR appearance of struma ovarii is thought to be a mixed mass composed of T2-hyperintense solid components with intense contrast enhancement and multiple T1-hyperintense cystic areas suggestive of hemorrhagic degeneration and viscous proteinaceous colloid.

Mutation and allelic loss of the p53 gene in endometrial carcinoma. Incidence and outcome in 92 surgical patients

BACKGROUND

Alterations of the p53 gene are involved in the development of diverse human malignancies, but their incidence and clinicopathologic features are still not well characterized for endometrial carcinoma.

METHODS

To investigate the clinicopathologic significance of p53, mutations and loss of heterozygosity (LOH) in endometrial carcinoma in 92 patients with this disease were examined.

RESULTS

Mutations of p53 were detected in 20 (22%) of the 92 patients with carcinoma, and LOH was detected in 23 (32%) of the 72 patients in whom heterozygosity of the gene was available. There was a significant correlation between the occurrence of mutation and LOH. Mutations and LOH were more frequent in patients with Grade 3 tumors than in those with Grades 1 and 2 tumors (P = 0.0498, P = 0.0051, respectively). Patients with LOH had a poorer postoperative survival than those without LOH (P = 0.0022, log-rank test), and patients with both LOH and mutation showed the worst prognosis (P < 0.0001, log rank test). Loss of heterozygosity of the p53 gene showed a significant relation to prognosis that was independent of tumor stage, histologic grade, and muscular invasion.

CONCLUSIONS

Mutation and LOH of the p53 gene are prognostic indicators in patients with endometrial carcinoma, suggesting that alterations of p53 may play an important role in the development of this cancer.

[Local injection of high-dose CDDP to the advanced gynecological cancer]

We investigated the efficacy of local injection of high-dose CDDP. The subjects were 16 patients with advanced gynecological cancer or tumor recurrence, in whom systemic administration of CDDP was inadvisable because of advanced age or associated complications (12 cases of cervical carcinoma, 2 cases of endometrial carcinoma, 1 case of ovarian carcinoma, and 1 case of vulvar carcinoma). In 14 cases, CDDP was injected locally to the tumor mass, using a single dose of 50-300 mg. In 2 cases, a single dose of 10-20 mg of CDDP was infused into the uterine cavity. The effects of the therapy were evaluated by cytodiagnosis, tumor markers, CT, and performance status. In all cases, an antitumor effect was noted, and seven subjects survived for at least 24 months following these therapy with CDDP. One patient developed vesicovaginal and rectovaginal fistulae after local injection of CDDP following high-dose radiotherapy. We investigated the plasma concentrations of free and total platinum after CDDP application with doses from 60-200 mg/body. Plasma concentrations showed a biphasic pattern (phase alpha and phase beta), and the peak plasma concentration of CDDP was lower than that following intravenous administration of the same dose. From these results, it was suggested that a large dose of CDDP can be injected into the tumor tissue itself and the surrounding tissue with comparatively few side effects. It will be possible to administer large dose of CDDP in this way to the terminal patients to whom there is currently no other appropriate method of treatment. The performance status of our subjects was improved, and we expect that wider use of this method will improve the quality of life for end-stage patients.

[Study on management of low potential malignancy ovarian tumors]

Thirty-six patients with low potential malignancy ovarian tumors were treated at our hospital from 1972 to 1986. Of these, 80.6% were classified as stage I, 5.6% as stage II, and 13.9% as stage III. Sixteen patients were treated by simple total hysterectomy and bilateral salpingo-oophorectomy, 15 patients by unilateral salpingo-oophorectomy, 2 patients by enucleation of the tumor, and 3 patients by exploratory laparotomy. In stage I no difference between the survival rates for the conservative therapy group and the radical therapy group was seen. Postoperative radiation therapy was given to 4 patients with dysgerminoma, and chemotherapy was given to 13 other patients. The five-year survival rate for stage I was 91.7%, better than for stage I malignant ovarian tumors, which was 78.9%. But the five-year survival rate for stage II and stage III was 0%. Analysis indicated that: 1. Prognosis of stage I patients is so good that treatments may be done in consideration of the patient's fertility. 2. The importance of adequate postoperative treatment and of strict follow up to guard against recurrence of malignancy is important in patients with stage II or stage III disease.