[Analysis of the clinical characteristics and misdiagnosis of area postrema syndrome manifesting as intractable nausea, vomiting, and hiccups in neuromyelitis optica spectrum disorders].

Objective: To investigate the misdiagnosis of area postrema syndrome (APS) manifesting as intractable nausea, vomiting and hiccups in neuromyelitis optic spectrum disease (NMOSD) and reduce the risk of misdiagnosis. Methods: We retrospectively analyzed data from NMOSD patients attending the Department of Neurology at the First Medical Center of PLA General Hospital between January 2019 and July 2021. SPSS25.0 was then used to analyze the manifestations, misdiagnosis, and mistreatment of APS. Results: A total of 207 patients with NMOSD were included, including 21 males and 186 females. The mean age of onset was 39±15 years (range: 5-72 years). The proportion of patients who were positive for serum aquaporin 4 antibody was 82.6% (171/207). In total, 35.7% (74/207) of the NMOSD patients experienced APS during the disease course; of these patients, 70.3% (52/74) had APS as the first symptom and 29.7% (22/74) had APS as a secondary symptom. The misdiagnosis rates for these conditions were 90.4% (47/52) and 50.0% (11/22), respectively. As the first symptom, 19.2% (10/52) of patients during APS presented only with intractable nausea, vomiting and hiccups; 80.8% (42/52) of patients experienced other neurological symptoms. The Departments of Gastroenterology and General Medicine were the departments that most frequently made the first diagnosis of APS, accounting for 54.1% and 17.6% of patients, respectively. The most common misdiagnoses related to diseases of the digestive system and the median duration of misdiagnosis was 37 days. Conclusions: APS is a common symptom of NMOSD and is associated with a high rate of misdiagnosis. Other concomitant symptoms often occur with APS. Gaining an increased awareness of this disease/syndrome, obtaining a detailed patient history, and performing physical examinations are essential if we are to reduce and avoid misdiagnosis.

Updating species diversity of Colletotrichum, with a phylogenomic overview.

The genus Colletotrichum includes important plant pathogens, endophytes, saprobes and human pathogens. Even though the polyphasic approach has facilitated Colletotrichum species identification, knowledge of the overall species diversity and host distribution is largely incomplete. To address this, we examined 952 Colletotrichum strains isolated from plants representing 322 species from 248 genera, or air and soil samples, from 87 locations in China, as well as 56 strains from Saudi Arabia, Thailand, Turkey, and the UK. Based on morphological characteristics and multi-locus phylogenetic analyses, the strains were assigned to 107 species, including 30 new species described in this paper and 18 new records for China. The currently most comprehensive backbone tree of Colletotrichum, comprising 16 species complexes (including a newly introduced C. bambusicola species complex) and 15 singleton species, is provided. Based on these analyses, 280 species with available molecular data are accepted in this genus, of which 139 have been reported in China, accounting for 49.6 % of the species. Colletotrichum siamense, C. karsti, C. fructicola, C. truncatum, C. fioriniae, and C. gloeosporioides were the most commonly detected species in China, as well as the species with the broadest host range. By contrast, 76 species were currently found to be associated with a single plant species or genus in China. To date, 33 Colletotrichum species have been exclusively reported as endophytes. Furthermore, we generated and assembled whole-genome sequences of the 30 new and a further 18 known species. The most comprehensive genome tree comprising 94 Colletotrichum species based on 1 893 single-copy orthologous genes was hence generated, with all nodes, except four, supported by 100 % bootstrap values. Collectively, this study represents the most comprehensive investigation of Colletotrichum diversity and host occurrence to date, and greatly enhances our understanding of the diversity and phylogenetic relationships in this genus. Taxonomic novelties: New species: Colletotrichum arecacearum F. Liu, Z.Y. Ma & L. Cai, Colletotrichum bicoloratum F. Liu, W.P. Wu & L. Cai, Colletotrichum bromeliacearum F. Liu & L. Cai, Colletotrichum buxi F. Liu, W.P. Wu & L. Cai, Colletotrichum chamaedoreae F. Liu, W.P. Wu & L. Cai, Colletotrichum crousii F. Liu, Z.Y. Ma & L. Cai, Colletotrichum danxiashanense F. Liu, W.P. Wu & L. Cai, Colletotrichum diversisporum F. Liu, W.P. Wu & L. Cai, Colletotrichum diversum F. Liu & L. Cai, Colletotrichum dolichoconidiophori F. Liu, W.P. Wu & L. Cai, Colletotrichum iris F. Liu & L. Cai, Colletotrichum monsterae F. Liu, W.P. Wu & L. Cai, Colletotrichum multiseptatum F. Liu, W.P. Wu & L. Cai, Colletotrichum nageiae F. Liu, W.P. Wu & L. Cai, Colletotrichum obovoides F. Liu & L. Cai, Colletotrichum parabambusicola F. Liu, W.P. Wu & L. Cai, Colletotrichum paraendophytum F. Liu, W.P. Wu & L. Cai, Colletotrichum reniforme F. Liu, Z.Y. Ma & L. Cai, Colletotrichum schimae F. Liu, W.P. Wu & L. Cai, Colletotrichum shivasii F. Liu & L. Cai, Colletotrichum sinuatum F. Liu, W.P. Wu & L. Cai, Colletotrichum subacidae F. Liu, Z.Y. Ma & L. Cai, Colletotrichum subsalicis F. Liu & L. Cai, Colletotrichum subvariabile F. Liu, W.P. Wu & L. Cai, Colletotrichum syngoniicola F. Liu, Z.Y. Ma & L. Cai, Colletotrichum telosmae F. Liu, W.P. Wu & L. Cai, Colletotrichum tibetense F. Liu & L. Cai, Colletotrichum variabile F. Liu, W.P. Wu & L. Cai, Colletotrichum zhaoqingense F. Liu & L. Cai, Colletotrichum zhejiangense F. Liu, W.P. Wu & L. Cai. Citation: Liu F, Ma ZY, Hou LW, Diao YZ, Wu WP, Damm U, Song S, Cai L (2022). Updating species diversity of Colletotrichum, with a phylogenomic overview. Studies in Mycology 101: 1-56. doi: 10.3114/sim.2022.101.01.

[Correlation analysis of the prognostic value of serum hyaluronic acid for breast cancer patients].

Objective: To explore the correlation between preoperative serum hyaluronic acid (HA) level and prognosis of breast cancer patients. Methods: The 98 patients with breast cancer who underwent surgical treatment in the Oncology Department of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine from January 2004 to November 2014 in a historical cohort were included, aged (52.5±9.4) years.The preoperative serum HA contents of the patients were detected. According to the median of 53.7 µg/L, the patients were divided into high and low groups with 49 patients in each group.The χ2 test was used to analyze the correlation between the serum HA content and the general clinical data of the patients, and the Kaplan-Meier method, Log-rank test and multivariate Cox regression model wereusedto analyze the correlation between HA content and patients' survival. Results: The percentages of patients with high HA levels in menopause and non-menopause patientswere 55.7% and 40.5%, respectively; in progesterone receptor (PR) positive and negative patients were 54.1% and 43.2%, respectively; in estrogen receptor (ER) positive and negative patients were 45.7% and 60.7%, respectively; in Ki-67 positive and negative patients were 55.6% and 43.2%, respectively; in the tumor size stage TⅠ, TⅡ, TⅢ, and TⅣ patients were 50.0%, 41.7%, 72.7%, and 1/1, respectively; in lymph node metastasis and non-metastasispatients were 45.7% and 53.8%, respectively. There was no significant correlation between the level of HA and the menopausal status, the expressions of PR, ER and Ki-67, tumor size, and lymph node metastasis in breast cancer patients (χ²=2.128, 1.086, 1.800, 1.485, 4.273, 0.656, P>0.05). Patients with high HA levels accounted for 30.9% of patients aged 52 years or less and 74.4% of patients older than 52 years (χ²=18.274, P=0.000); 43.4% of patients with early TNM and 72.7% of patients with advanced TNM (χ²=5.861, P=0.015); 45.2% of patients without distant metastasis and 78.6% of patients with distant metastasis (χ²=5.333, P=0.023); 38.1% of Her-2 negative patients and 58.9% of Her-2 positive patients(χ²=4.167, P=0.041); and the median survival of patients with high HA levels was 70 months, which was shorter than 83 months for patients with low HA levels (χ²=6.799, P=0.007). Therefore, ahigh HA content predicts an older age, a later tumor stage, higher risk of distant metastasis, positive expression of Her-2 and shorter survival. Multivariate Cox regression model analysis suggested that high levels of serum HA may be a risk factor for patients' survival, with HR (95%CI) value of 9.98 (1.16-85.88) and P value of 0.036. Conclusion: The high level of preoperative serum HA has a certain correlation with the poor prognosis of breast cancer patients.

Anticancer activity of Bombyx batryticatus ethanol extract against the human tumor cell line HeLa.

Anticancer activity of Bombyx batryticatus ethanol extract (BBE) against HeLa cells was studied using cell viability, DNA fragmentation, real-time polymerase chain reaction, and Western blot analyses. The BBE inhibited the growth and induced apoptosis of HeLa cells. The MTT assay indicated that the BBE induced cytotoxicity in HeLa cells in a time- and concentration-dependent manner. When HeLa cells were treated for 48 h, the 50% inhibitory concentration (IC50) value for the BBE was 1.564 mg/mL. The microscopy results showed that HeLa cells were severely distorted and showed slow growth; some cells became round in shape when treated with 5 mg/mL BBE for 24 h. The DNA ladder results revealed excessive DNA fragmentation in HeLa cells treated with 7 mg/mL BBE for 36 h. The proapoptotic activity of the BBE was attributed to its ability to modulate the expression of Bcl-2 and Bax genes. The mRNA and protein expression levels of Bax were remarkably higher whereas those of Bcl-2 were lower than those in the control cells; this led to an increased Bax/Bcl-2 ratio in cells treated with the BBE for 36 h. The results suggest that the BBE might play an important role in tumor growth suppression by inducing apoptosis in human cervical cancer cells via the regulation of the Bcl-2- and Bax-mediated apoptotic pathways.

A village-based multidisciplinary study on factors affecting the intensity of cystic echinococcosis in an endemic region of the Tibetan plateau, China.

SUMMARY: We investigated and quantified the factors which may affect the prevalence of cystic echinococcosis caused by Echinococcus granulosus in Rangtang County using a multidisciplinary approach. From a previously performed field survey, epidemiological data were linked with environmental data. Altitude and land surface temperature were extracted from remote-sensing images. Cumulative logistic regression models were used to identify and quantify the potential risk factors. The multiple regression models confirmed that yaks (χ 2 = 4·0447, P = 0·0443), dogs (χ 2 = 8·3455, P = 0·0039) and altitude (χ2 = 7·6223, P = 0·0058) were positively correlated with the prevalence of cystic echinococcosis, while land surface temperature may have a negative association. The findings showed that dogs and yaks play the most important role in the transmission of cystic echinococcosis, while altitude and land surface temperature may also be involved in the transmission.

Echinococcus infections in Chinese dogs: a comparison of coproantigen kits.

Coproantigen test kits for Echinococcus spp. worms in dogs, designed for commercial use, were obtained from three different Chinese producers, and were compared with a laboratory kit using reagents from New Zealand. None of the three producers would provide details of their test validation. From a known set of dog faeces obtained at necropsy from infected and uninfected dogs, and from faeces collected from dogs necropsied in the field, results differed between the kits. For field material, the Tiankang kit showed the best specificity but lacked sensitivity. The Combined kit showed best sensitivity but lacked specificity. Results for the Haitai kit were intermediate. With samples from experimentally infected dogs, both the Haitai and Combined kits lacked sensitivity. Kits will need to be validated by the user before they can be relied on to predict progress in Echinococcus spp. control in China or in other countries.

[Progress of researches on infection with two species of Echinococcus causing human diseases in animal hosts and influencing factors].

Echinococcosis is a serious zoonotic parasitic disease caused by infections with larval Echinococcus. The life cycle of Echinococcus involves a variety of animal hosts, including hoofed animals and rodents as intermediate hosts and carnivores as definitive hosts. The transmission of human echinococcosis is closely associated with the life cycle of E. granulosus and E. multilocularis among animal hosts in nature. This review summarizes the recent advances in the prevalence and influencing factors of E. granulosus and E. multilocularis infections in animal hosts, so as to provide insights into precision control of echinococcosis.

[Effectiveness of a new health education pathway for echinococcosis control among primary school students in hyper-endemic regions].

OBJECTIVE: To investigate the effectiveness of a new health education pathway for echinococcosis control among primary school students in regions highly prevalent for echinococcosis in China. METHODS: Six primary schools were randomly selected from echinococcosis hyper-endemic regions, with 13 classes assigned to the intervention group and 9 to the control group, and all students in these 21 classes were recruited as the study subjects. Echinococcosis health education was performed through the pathway of assessing the current status-strengthening the building of teaching resources-focusing on practices in the intervention group, while routine health education was given in the control group. A questionnaire survey was performed to assess the score of echinococcosis control knowledge (including theoretical knowledge score and mean daily practical capability score) before and after the health education interventions to evaluate the effectiveness of this new health education pathway for echinococcosis control. RESULTS: The mean score of echinococcosis control knowledge was 68.86 ± 18.70 points at baseline, with the mean theoretical knowledge score of 40.97 ± 10.75 points, and the mean daily practical capability score of 27.89 ± 12.50 points. Clustering analysis showed three types of populations, including "unsatisfactory", "learn and apply creatively", and "rote learning", which accounted for 24.62% (240/975), 45.74% (446/975) and 29.64% (289/975), respectively. The mean score of echinococcosis control knowledge was 81.08 ± 18.15 points in the intervention group during the final assessment, with the mean theoretical knowledge score of 43.65 ± 9.40 points, and the mean daily practical capability score of 37.43 ± 12.22 points, and both were significantly higher relative to baseline (t = -4.201 and -15.202, both P values < 0.01). The mean score of echinococcosis control knowledge was comparable between at baseline (70.55 ± 19.46 points) and final assessment (71.74 ± 19.37 points) in the control group (t = -0.87, P > 0.05). CONCLUSIONS: The awareness of echinococcosis control knowledge is fair among primary school students in echinococcosis hyper-endemic regions; however, the capability of combining theoretical learning and practices requires to be improved. The health education mode based on the pathway of assessing the current status-strengthening the building of teaching resources-focusing on practices seems to remarkably improve the understanding of echinococcosis control knowledge among primary school students in echinococcosis hyper-endemic regions.

[Epidemiological characteristics of Kala-azar disease in China, during 2005-2015].

Objective: To explore the epidemiological characteristics of Kala-azar disease in China from 2005 to 2015, to provide evidence for the development of related control and measurement strategies. Methods: Data was obtained from Disease Reporting Information System of China CDC, to compare factors on type, distribution, peak season and the age of onset of the cases. Results: Epidemic of Kala-azar had been persistent in China. Number of the reported cases declined in Sichuan and Gansu provinces but two outbreaks had occurred in Xinjiang Uygur autonomous region. The epidemic was confined in few areas. The reported cases were mainly from Xinjiang, Gansu and Sichuan, with the total cases in these three provinces accounted for 95.29% of all the cases seen in the country. The main peak season was from October to November, followed by April. There were significant differences seen in the age distributions of canine Kala-azar, anthroponotic Kala-azar and wildlife-oriented Kala-azar (P<0.05) cases. Majority of the cases involved under 3-year-olds, with peak age in under 1-year-olds for wildlife-oriented Kala-azar. For anthroponotic and canine Kala-azar cases, most of them were seen among the under 10 years old, with the peak among the 5-year-olds. Conclusions: In recent years,Kala-azar had been seen endemic and persistent, in the mid-west regions of China, but with different epidemiological characteristics. Further study on Kala-azar should be carried on to include appropriate measurements and strategies, according to the features of the disease, in the mid-western areas of China.

Decreased inflammatory pain due to reduced carrageenan-induced inflammation in mice lacking adenosine A3 receptors.

Mice with a targeted disruption of adenosine A(3) receptor (A(3)AR) gene were assessed for their nociceptive threshold and for their localized inflammatory response following carrageenan injected into the hindpaw. Under basal conditions no difference was seen between A(3)AR knock-out (A(3)AR(-/-)) and wild-type (A(3)AR(+/+)) mice in nociceptive response to mechanical or heat stimuli. The antinociceptive response to the intrathecal adenosine analogue R-phenylisopropyl adenosine (R-PIA) was also unchanged in the A(3)AR(-/-) mice. In contrast, heat hyperalgesia, plasma extravasation and edema following carrageenan-induced inflammation in the hind paw were significantly reduced in A(3)AR(-/-) mice compared to the A(3)AR(+/+) controls. Thus, mice lacking A(3)AR had deficits in generating the localized inflammatory response to carrageenan, supporting a pro-inflammatory role of A(3)AR in peripheral tissues. However, no evidence for a role of A(3)AR in nociception and the antinociceptive effect of R-PIA was found.

Intrathecal administration of PNA targeting galanin receptor reduces galanin-mediated inhibitory effect in the rat spinal cord.

Peptide nucleic acids (PNA) are nucleic acid analogues containing neutral amide backbone, forming stable and tight complexes with complementary DNA/RNA. However, it is unclear whether unmodified PNA can efficiently penetrate neuronal tissue in order to act as antisense reagent. Here we show that intrathecal (i.t.) injection of an unmodified antisense PNA complementary to the rat galanin receptor type 1 (GalR1) mRNA is able to block the inhibitory effect of i.t. administered galanin on spinal nociceptive transmission. Autoradiographic ligand binding studies using [125I]galanin show that the unmodified PNA is able to reduce the density of galanin binding sites in the dorsal horn. Thus, unmodified PNA applied i.t. appears to function as an effective antisense reagent in rat spinal cord in vivo.

Increased level of cholecystokinin in cerebrospinal fluid is associated with chronic pain-like behavior in spinally injured rats.

Cholecystokinin (CCK) is a physiological antagonist of opioid-mediated antinociception and may be involved in some chronic pain states where opioids have reduced effect. We have previously shown in a rat model of central neuropathic pain after spinal cord injury that blockade of CCK-B receptors lead to marked pain relief. In the present study, we showed that spinally injured rats exhibiting chronic pain-like behaviors (aversive reaction to innocuous mechanical and cold stimulation) had significantly elevated level of CCK-like immunoreactivity in cerebrospinal fluid compared to normal rats or spinally injured rats which did not exhibit pain-like behaviors. The increased level of circulating CCK in the cerebrospinal fluid may thus contribute to the maintenance of chronic pain in these rats by reducing the endogenous inhibitory tone provided by opioid peptides and may be involved in the phenomenon of opioid insensitivity.

Lack of stereoselectivity for the antiallodynic effect of mexiletine in spinally injured rats.

Systemically administered mexiletine, an antiarrhythmic, has been shown to also possess analgesic properties in some conditions of neuropathic pain. It has been suggested that the analgesic effect of mexiletine may be derived from the action of one of its optical isomers, (+)(S)-mexiletine. In the present study, we have compared the effects of systemic (-)-(R)- and (+)-(S)-mexiletine, on chronic mechanical allodynia-like behaviour in spinally injured rats, a model of central neuropathic pain in which racemic mexiletine has been shown to be active. I.p. racemic mexiletine as well as (-)-(R)- and (+)(S)-mexiletine at 25 mg/kg all produced significant, but brief, alleviation of mechanical allodynia in a similar fashion as assessed with von-Frey hair elicited vocalization in the spinally injured rats. A slight increase in motor impairment was observed in all three groups which reached statistical significance for the racemic mexiletine and (+)-(S)-mexiletine. Our results suggest that both isomers of mexiletine contribute to the antiallodynic effect in this model of central pain.

[Resistant action of gangliosides on the 6-OHDA injured sympathetic nerves].

A single dose of 6-OHDA (15 mg/kg i.p.) would cause an almost complete disappearance of catecholamine fluorescence in histological preparation of submandibular glands (SMG) 24 hours after injection. Recovery of NA and DA levels went on slowly along with the course of regeneration of the lesioned sympathetic nerve terminals. The NA and the DA contents reached 50% and 28% respectively two weeks after lesion and fully recovered by the end of the fourth week. Gangliosides mixture (GM) (50 mg/kg i.p.) given 0, 4, 8, and 12 hours after 6-OHDA injection could prevent the injury action of NA and DA for at least 24 hours. If this treatment was followed by daily injection for one week, the NA contents remained normal by the end of two weeks. GM treatments beginning either 4 days before or 4 hours after 6-OHDA injection could lessen the extent of decrease of NA and DA by 6-OHDA. The results suggest that: a) GM is effective in protecting the membrane of sympathetic terminals from the injurious effect of 6-OHDA or 6-OHDA metabolites and promoting the regeneration of the lesioned terminals. b) The earlier the GM treatments are given, the better will be the effects.

[Influence of septohippocampal lesion on the levels of some neurotransmitters and enzymes in the rat hippocampus].

Partial deafferentation of the hippocampus was obtained by transection of unilateral partial fimbria-fornix. On the seventh postoperational day, there appeared in the lesioned hippocampus respectively a 72.5%, 45.7% and 52.2% reduction in acetylcholine content, choline acetyltransferase and cholinesterase activity. A concomitant 16.3%, 31.1% and 30.3% reduction in noradrenaline, dopamine and serotonin content respectively was also observed, while amino acids content did not show any change. The results indicate that the cholinergic and monoaminergic afferents of the hippocampal formation in the rat reach their target regions via the fimbria-fornix.

The effect of radix Salviae miltiorrhizae on vasoactive intestinal peptide in cerebral ischemia: an animal experiment.

The levels of vasoactive intestinal peptide (VIP) in three regions of rat brain were assayed in 62 rats. Bilateral common carotid artery ligation was done in 50 rats. Half an hour before ligation 26 rats were given 10 g/kg of Radix Salviae Miltiorrhizae (RSM); 24 rats were given same volume of normal saline as controls. A sham operation was done in 12 rats. Half an hour (n = 30) and 3 hours (n = 32) after operation, the rats were quickly decapitated. VIP levels were assayed in cerebral cortex, hippocampus and caudate nucleus. In salin-treated animals, VIP levels of cerebral cortex and caudate nucleus at 3 hour group were significantly decreased compared with the sham-operated group. No significant difference was found between RSM-treated and sham-operated groups. The preliminary results suggest that VIP may be involved in the pathophysiological procedures of cerebral ischemia and RSM may attenuate the dysfunction of VIP during cerebral ischemia.

Structural mutations in the constant region of the T-cell antigen receptor (TCR)beta chain and their effect on TCR alpha and beta chain interaction.

The region responsible for T-cell receptor (TCR)alpha and beta chain assembly has previously been shown to reside in their extracellular domains. In an attempt to delineate further the structural requirements for TCR alpha and beta chain assembly, chimeric TCR beta chains with increasing length of constant (C) region and mutant TCR beta chains with C-domain point mutations were constructed. Their ability to assemble with wild-type TCR alpha chain was evaluated in non-T (COS cells) or T cells. The results reveal that the C beta domain is the binding region to TCR alpha chain, whereas the intact variable (V), diversity (D) and joining (J) regions with a short C-domain of beta chain are not sufficient for the TCR alpha and beta chain assembly. The unique interchain disulphide bond between TCR alpha and beta chains is not required for the TCR alpha beta heterodimer formation.

Emergency department-based telemedicine.

Although many studies have been published concerning clinical telemedicine, little information is available about emergency department (ED)-based telemedicine programs. An ED-based telemedicine program was initiated in April 1996 involving the National Cheng Kung University Hospital (NCKUH) and the Provincial Peng-Hu Hospital (PPHH) under a pilot project supported by the Department of Health. This is the first telemedicine program for remote offshore island service in Taiwan. The program is synchronous in nature to the practice of telemedicine. The role of the emergency physician includes giving initial suggestions, arranging consultations, coordination, and the organization of other medical tasks, such as accompanying some of the transfers. During the 12-month period, this system was used in 275 consultations, including 24 specialty and/or subspecialty department/sections, and more than 100 members of the medical staff have participated in this project since. In a survey, 89.4% of physicians in the PPHH and 82.2% of the physicians in NCKUH rated the system as very comfortable to work with and satisfactory. According to these observations, an ED-based telemedicine program is a feasible method for carrying out remote consultations. Successful development of the partnership and program of telemedicine is based on the active participation and coordination of the medical personnel and technicians between the cooperating hospitals.

Aflatoxin exposure and risk of hepatocellular carcinoma in Taiwan.

To investigate the carcinogenic effect of environmental aflatoxin exposure, 56 cases of hepatocellular carcinoma (HCC) diagnosed between 1991 and 1995 were identified and individually matched by age, sex, residence and date of recruitment to 220 healthy controls from the same large cohort in Taiwan. Blood samples were analyzed for hepatitis B and C viral markers and for aflatoxin-albumin adducts; urine was tested for aflatoxin metabolites. We obtained information about sociodemographic characteristics, habitual alcohol drinking, cigarette smoking and diet in a structured interview. Hepatitis B virus surface antigen (HBsAg) carriers had a significantly increased risk for HCC. After adjustment for HBsAg serostatus, the matched odds ratio (ORm) was significantly elevated for subjects with high levels of urinary aflatoxin metabolites. When stratified into tertiles, a dose-response relationship with HCC was observed. The ORm for detectable aflatoxin-albumin adducts was not significant after adjustment for HBsAg serostatus. HBsAg-seropositive subjects with high aflatoxin exposure had a higher risk than subjects with high aflatoxin exposure only or HBsAg seropositivity only. In male HBsAg-seropositive subjects, adjusted ORs were 2.8 (95% confidence interval [CI] = 0.9-9.1) for detectable compared with non-detectable aflatoxin-albumin adducts and 5.5 (CI = 1.3-23.4) for high compared with low urinary aflatoxin metabolite levels. Our results suggest that environmental aflatoxin exposure may enhance the hepatic carcinogenic potential of hepatitis B virus. A large-scale study will be needed to evaluate the effect of aflatoxin exposure on HBsAg non-carriers.