A 4-year study of the mycological aspects of Kashin-Beck disease in Tibet

Modulatory interactions of T-2 and deoxynivalenol mycotoxins on murine femoral development and osteological integrity

In this study, we conducted a systematic assessment of the effectsof deoxynivalenol (DON) and T-2 mycotoxins (T-2) on the developmental processes and structural integrity of murine femurs, considering both the isolated and synergistic effects of these toxins. To this end, we divided 72 male mice into nine groups, each subjected to varying dosages of T-2, DON, or their combinations. Over a four-week experimental period, meticulous monitoring was undertaken regarding the mice's body weight, biochemical markers of bone formation and resorption, and the activity of relevant cells. To comprehensively evaluate alterations in bone structure, we employed biomechanical analysis, micro-computed tomography (micro-CT), and transmission electron microscopy.Our findings unveiled a significant revelation: the mice exhibited a dose-dependent decrease in body weight upon exposure to individual mycotoxins, while the combined use of these toxins manifested an atypical antagonistic effect. Furthermore, we observed variations in the levels of calcium, phosphorus, and vitamin D, as well as adjustments in the activities of osteoblasts and osteoclasts, all intricately linked to the dosage and ratio of the toxins. Alterations in biomechanical properties were also noted to correlate with the dosage and combination of toxins. Analyses via micro-CT and transmission electron microscopy further corroborated the substantial impact of toxin dosage and combinations on both cortical and trabecular bone structures.In summation, our research unequivocally demonstrates the dose- and ratio-dependent detrimental effects of DON and T-2 mycotoxins on the growth and structural integrity of murine femurs. These insights accentuate the importance of a profound understanding of the potential risks these toxins pose to bone health, offering pivotal guidance for future toxicological research and public health preventative strategies.

Mycotoxins and bone growth: a review of the literature on associations between xenobiotic exposure and bone growth and development

Mycotoxins are secondary metabolites of fungi that are known to be associated with linear growth faltering because of their impact on inflammation, intestinal damage, inhibition of protein synthesis, and micronutrient absorption. In this narrative review, we aim to extend this analysis to further explore associations between mycotoxins (aflatoxins, ochratoxins, trichothecenes including deoxynivalenol, T-2 toxin, and fumonisins) and long-bone growth, particularly during the saltatory periods of development. Linear growth is a direct function of skeletal development and long-bone growth. We therefore explored biological pathways and mechanisms of impact of these toxins in both animal and human studies, in addition to the epidemiology literature (post-2020). Given what is known of the effects of individual and combinations of mycotoxins based on the animal literature, we have identified a need for further research and examination of how these toxins and exposures may be studied in humans to elucidate the downstream impact on bone-related biomarkers and anthropometric indices used to identify and predict stunting in population-based studies.

Untargeted Metabolomics Approach Correlated Enniatin B Mycotoxin Presence in Cereals with Kashin-Beck Disease Endemic Regions of China

Kashin-Beck disease (KBD) is a multifactorial endemic disease that only occurs in specific Asian areas. Mycotoxin contamination, especially from the Fusarium spp., has been considered as one of the environmental risk factors that could provoke chondrocyte and cartilage damage. This study aimed to investigate whether new mycotoxins could be identified in KBD-endemic regions as a potential KBD risk factor. This was investigated on 292 barley samples collected in Tibet during 2009-2016 and 19 wheat samples collected in Inner Mongolia in 2006, as control, from KBD-endemic and non-endemic areas. The LC-HRMS(/MS) data, obtained by a general mycotoxin extraction technic, were interpreted by both untargeted metabolomics and molecular networks, allowing us to identify a discriminating compound, enniatin B, a mycotoxin produced by some Fusarium spp. The presence of Fusarium spp. DNA was detected in KBD-endemic area barley samples. Further studies are required to investigate the role of this mycotoxin in KBD development in vivo.

Case report: A 3-year follow-up study of simultaneous bilateral total hip arthroplasty for Femoral head necrosis in a patient with Kashin-Beck Disease

Introduction

Kashin-Beck Disease (KBD) is an endemic disease predominantly affecting joint and skeletal muscle, predisposing the articular cartilage to degeneration and necrosis. Currently,staged total hip arthroplasty is a common surgical method for advanced femoral head necrosis from KBD, but there are no reports in the literature on simultaneous bilateral total hip arthroplasty (SB-THA) for patients with KBD.

Case presentation

A 42-year-old male from Shaanxi Province, an endemic area, had bilateral hip pain for 4 years, with hips inversion and a crossed gait. After preoperative preparation, a SB-THA was performed by a posterolateral approach. Postoperative medication and functional exercises were administered and the patient was followed up for at least 3 years after discharge. The patient's hip mobility, hip scores and quality of life scores were recorded in detail during the follow-up.

Result

The patient stopped antibiotic treatment on the postoperative day-2, and all inflammatory indicators showed normal and started appropriate exercise, and the pain score decreased significantly. On the postoperative day-7, the patient had gradually adapted to various forms of rehabilitation exercises. He was discharged from the hospital on the postoperative day-10 and continued to be followed up. From the preoperative period to the last follow-up, the patient's bilateral hip mobility and functional scores improved significantly, and no adverse events such as hip pain, prosthesis loosening or dislocation were found at the last follow-up.

Conclusion

The patient's performance was satisfactory both intraoperatively and in the early postoperative period, but the hip scores and quality of life scores began to plateau or even decline from the third year after surgery to the last follow-up, probably due to the influence of further damage to articular cartilage in other parts of the body.

Ecological analysis of Kashin-Beck osteoarthropathy risk factors in Tibet's Qamdo City, China

We studied Tibet’s Qamdo City, which currently hosts the most serious prevalence of Kashin-Beck osteoarthropathy (KB) in China. This study utilizes the geographical detector (GeoDetector) algorithm to measure the individual and interactive influences of risk factors on KB and to quantify the highest potential risk subzones of each principal factor. With a comprehensive consideration of 13 possible related factors, namely, the tectonic division, stratum, moisture index, gross domestic product, mean annual precipitation, soil type, groundwater type, elevation, mean annual temperature, vegetation type, geomorphic type, slope degree and slope aspect, our results indicate that the main exposure factors for KB in Qamdo City are geological factors (tectonic division and stratum), wetting factors (moisture index and mean annual precipitation), and an economic factor (gross domestic product). In contrast, other factors have little effect on the prevalence of KB in Qamdo City. All 13 factors either nonlinearly or bivariately enhance each other, and the interactions between these factors can increase the prevalence of KB. Consequently, it can be inferred that KB in Qamdo City is caused primarily by a set of multiple and interrelated disease risk factors.

Cellular responses to T-2 toxin and/or deoxynivalenol that induce cartilage damage are not specific to chondrocytes

The relationship between T-2 toxin and deoxynivalenol (DON) and the risk of Kashin-Beck disease is still controversial since it is poorly known about their selectivity in cartilage damage. We aimed to compare the cytotoxicity of T-2 toxin and DON on cell lines representative of cell types encountered in vivo, including human chondrocytes (C28/I2), human hepatic epithelial cells (L-02) and human tubular epithelial cells (HK-2). In addition, we determined the distribution of T-2 toxin and DON in Sprague-Dawley (SD) rats after a single dose exposure. T-2 toxin or DON decreased proliferation in a time- and concentration-dependent manner and their combination showed a similar antagonistic effect in C28/I2, L-02 and HK-2 cells. Moreover, we observed cell cycle arrest and apoptosis, associated with increased oxidative stress and decline in mitochondrial membrane potential induced by T-2 toxin and/or DON. In vivo study showed that T-2 toxin and DON did not accumulate preferentially in the knee joint compared to liver and kidney after an acute exposure in SD rats. These results suggest that T-2 toxin and/or DON inhibit proliferation and induce apoptosis through a possible mechanism involving reactive oxygen species-mediated mitochondrial pathway that is not specific for chondrocytes in vitro or joint tissues in vivo.

Reliability and validity of the 12-item WHODAS 2.0 in patients with Kashin-Beck disease

The purpose of this study was to check the reliability and validity of the 12-item Chinese version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) for the assessment of disability in patients with Kashin-Beck disease (KBD). We recruited 219 patients with KBD from the high-risk KBD area in the Shaanxi province, using stratified multistage random sampling. We assessed each patient using the Chinese version of the 12-item WHODAS 2.0 and the Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC). Statistical evaluations of the instruments consisted of Cronbach's alpha, intraclass correlation coefficient (ICC), confirmatory factor analysis (CFA), and Pearson's correlation coefficient. Cronbach's alpha and ICC for the six domains ranged from 0.704 to 0.906 and 0.690 to 0.852, respectively. A six-factor structure fits the data well (CFI = 0.967, TLI = 0.944, RMSEA = 0.08). Regarding convergent validity, the four domains of the 12-item WHODAS 2.0 (getting around, self-care, life activity, and participation) showed moderate-to-strong correlation for all three domains of the WOMAC (0.428 < |r| < 0.804). Regarding divergent validity, the two domains of the 12-item WHODAS 2.0 (understanding and communication, and getting along with people) showed weak correlation for the three domains of WOMAC (0.182 < |r| < 0.295). The Chinese version of 12-item WHODAS 2.0 questionnaire is a reliable and valid instrument when administered to KBD patients.

Total hip replacement in adult patients with severe Kashin-Beck disease of the hip

Background

The treatment of elderly patients with Kashin-Beck disease (KBD) remains clinically challenging, and clinical data are very lacking. The aim of this study was to retrospectively evaluate pain and functional outcomes following total hip replacement in adult patients with severe KBD of the hip.

Methods

Twenty-two patients (32 hips) with KBD underwent primary hip replacement and were followed for at least 2 years. Radiographic and Clinical assessments were evaluated for each patient at 2 and 4 weeks and at 3, 6 and 12 months after the operation and annually thereafter. The efficacy index included the visual analogue scale (VAS) score, Harris hip score, functional score for adult Tibetans with Kashin-Beck Disease (FSAT-KBD) and radiographic outcomes.

Results

The patients underwent a follow-up, and the mean follow-up time was 3.8 years. VAS scores significantly decreased within the first 6 months postoperatively. This decrease continued until the final follow-up (p < 0.01). This result was supported by a significant increase in the Harris and FSAT-KBD scores after the surgery (p < 0.01). At the final follow-up, there was no change in prosthesis positioning or radiographic evidence of prosthesis loosening. One case received impacted allograft bone croutons and had worn polyethylene components replaced after 6 years because the patient suffered severe pelvic and femoral osteolytic lesions postoperatively.

Conclusions

Hip replacement can relieve pain and improve joint function in treating severe KBD hip. Additional studies that are more extensive are needed to confirm the findings of our study.

Investigation of MMP-1 genetic polymorphisms and protein expression and their effects on the risk of Kashin-Beck disease in the northwest Chinese Han population

BACKGROUND

The etiology of Kashin-Beck disease (KBD), an endemic osteochondropathy, is largely unknown. Matrix metalloproteinase-1 (MMP-1) plays a central role in the initiation and progression of cartilage destruction; however, no study has reported on the relationship between KBD and MMP-1. This study was to investigate the role of MMP-1 in the pathogenesis and progression of KBD.

METHODS

Single nucleotide polymorphism (SNP) genotyping was conducted for 274 KBD cases and 248 healthy controls using the Sequenom MassARRAY system. Additionally, the expression of MMP-1 in the knee articular cartilage of 22 KBD patients and 21 controls was analyzed by immunohistochemistry, and the concentration of MMP-1 in their joint fluid was also measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The results showed that two SNPs (rs470221 and rs1144396) had a weak association with increased KBD risk; however, the significance of these results did not survive Bonferroni's correction. Moreover, the percentages of cells expressing MMP-1 in each layer of cartilage were significantly higher in the KBD group than in the controls (F = 11.41-28.31, P = 0.002-0.000). The concentration of MMP-1 in KBD joint fluid was significantly higher than that in the controls (t = 9.83, P < 0.0001).

CONCLUSIONS

The increased expression of MMP-1 has a potential effect on the risk of KBD in the northwest Chinese Han population. However, six selected SNPs in the MMP-1 gene might not be useful as significant markers for predicting KBD susceptibility in Chinese Han population. Therefore, future studies in the association of MMP-1 with KBD should focus on other candidate SNPs.

Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China

Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15 years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232 μg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255 μg/g) and the girls (0.222 μg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3 % of students with low Se status (hair Se <0.20 μg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa.

COL9A1 gene polymorphism is associated with Kashin-Beck disease in a northwest Chinese Han population

Objective

We sought to determine whether genomic polymorphism in collagen IX genes (COL9A) was associated with Kashin-Beck disease (KBD).

Methods

Twenty seven single nucleotide polymorphisms (SNPs) in COL9AI, COL9A2 and COL9A3 were genotyped in 274 KBD cases and 248 healthy controls using the Sequenom MassARRAY system. Associations between the COL9A polymorphism and KBD risk were detected using an unconditional logistic regression model. Linkage disequilibrium (LD) and haplotypes analysis were performed with the Haploview software.

Results

After Bonferroni correction, the frequency distribution of genotypes in rs6910140 in COL9A1 was significantly different between the KBD and the control groups (X² = 16.74, df = 2, P = 0.0002). Regression analysis showed that the allele “C” in SNP rs6910140 had a significant protective effect on KBD [odds ratio (OR) = 0.49, 95% confidence interval (CI) = 0.34–0.70, P = 0.0001]. The frequencies of alleles and genotypes in rs6910140 were significantly different among subjects of different KBD stages (allele: X² = 7.82, df = 2, P = 0.02, genotype: X² = 14.81, df = 4, P = 0.005). However, haplotype analysis did not detect any significant association between KBD and COL9A1, COL9A2 and COL9A3.

Conclusions

We observed a significant association between rs6910140 of COL9A1 and KBD, suggesting a role of COL9A1 in the development of KBD.

Serum levels of M-CSF, RANKL and OPG in rats fed with Kashin-Beck disease-affected diet

Objective

There were no studies on the macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) in the pathogenesis of Kashin-Beck disease (KBD). The objective of the present study was to investigate the serum M-CSF, RANKL and OPG in rats fed with KBD-affected diet.

Methods

Ninety Wistar rats were divided into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low protein feed with or without or T-2 toxin additive and the KBD-affected feed. The serum bioactivity of M-CSF, RANKL and OPG was tested by enzyme-linked immunosorbent assay.

Results

The serum levels of M-CSF in E group rats were higher than those in the other groups in the five groups (P < 0.01). The serum levels of RANKL and OPG in E group rats were highest in the five groups and have significant difference compared to the other groups (P < 0.05).

Conclusions

The molecule of M-CSF, RANKL and OPG may be involved in the regulation of epiphyseal plate injury and repair in KBD, and its participation in the pathogenesis of KBD should be studied in the future.

Magnetic resonance imaging in the tibial epiphyseal growth plate development of Wistar rat

OBJECTIVE

This research aims to investigate magnetic resonance imaging (MRI) in the tibial epiphyseal growth plate development of Wistar rat.

METHODS

Fifty weanling Wistar rats were divided by a computerized blocking procedure into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low-protein feed with or without T-2 toxin additive, and Kashin-Beck disease (KBD)-affected feed.

RESULTS

Compared with the control group rat, MRI showed localized epiphyseal plate swelling, rough appearance, and uneven signal on the tibia of rats fed with KBD-affected feed. Histology confirmed the epiphyseal plate degeneration seen by MRI, and the degenerative changes were characterized by abnormal distribution of chondrocytes with loss and clustering, cartilage fragmentation, and erosion in group E.

CONCLUSIONS

The MR image of the rat epiphyseal plate is altered in the KBD model rats, and epiphyseal plate MRI appearance has been reproduced by using T-2 toxin and KBD-affected feed of epidemic district.

An animal model of Kashin-Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

OBJECTIVE

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease.

METHODS

Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined.

RESULTS

In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P < 0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks.

CONCLUSIONS

A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.

Genetic variants in the HLA-DRB1 gene are associated with Kashin-Beck disease in the Tibetan population

OBJECTIVE

To investigate the association between variants in the HLA-DRB1 gene and Kashin-Beck disease (KBD), as well as associations of selenium and iodine deficiencies with KBD in a Tibetan population.

METHODS

Fourteen single-nucleotide polymorphisms (SNPs) were genotyped around the HLA-DRB1 gene, and HLA-DRB1 allele genotyping was performed in a discovery cohort, composed of 605 patients with KBD and 393 control subjects, and/or a replication cohort, composed of 290 patients with KBD and 295 controls. Plasma concentrations of selenium and iodine were measured and compared by t-test in 299 patients with KBD and 280 controls from the same villages.

RESULTS

Four SNPs (rs6457617, rs6457620, rs9275295, and rs7745040) in the HLA-DRB1 gene locus were significantly associated with KBD in both the discovery cohort and replication cohort (combined cohort odds ratios [ORs] 1.307-1.402, P = 0.0039-0.0006). The protective haplotype GTCC and the risk haplotype ACGT, each generated by the 4 SNPs, showed a significant association with KBD (for GTCC, OR 0.77, P = 0.0031; for ACGT, OR 1.40, P = 0.0014). HLA-DRB1 allele genotyping revealed that the frequencies of HLA-DRB1*08 and *11 were significantly different between patients with KBD and controls (for HLA-DRB1*08, OR 0.731, P = 0.00564; for HLA-DRB1*11, OR 0.489, P = 0.000395). Moreover, plasma concentrations of selenium and iodine were significantly different between patients with KBD and controls from the same villages (P = 0.0013 and P = 1.84 × 10(-12) , respectively).

CONCLUSION

These findings, obtained in plasma samples from Tibetan patients with KBD and healthy control subjects from the same regions, confirm the role of selenium and iodine deficiencies in the development of KBD. Moreover, genetic variants in the HLA-DRB1 gene significantly increase the susceptibility to KBD in this population.

Clinical features of Kashin-Beck disease in adults younger than 50 years of age during a low incidence period: severe elbow and knee lesions

More than one million people are affected by Kashin-Beck disease (KBD) in a limited endemic area. However, few studies focused on the clinical features of adult KBD patients. The aim of this study was to investigate the clinical features of adult KBD patients who were younger than 50 years of age during a low incidence period. A special questionnaire was designed that surveyed general data, clinical symptoms, and signs and included the Visual Analogue Scale (VAS). Anthropometrics, the joint VAS, the range of joint motion (ROM), and joint function were measured. The VAS and joint dysfunction were compared among the different joints of extremities, and the relationship among the VAS, ROM, age, course of KBD, and number of enlarged knee and elbow joints elbow was analyzed. Two hundred forty-nine adult Tibetan KBD patients, matched with 249 healthy control subjects, have been surveyed. The VAS results show that the knee is the joint associated with the most pain, followed by the elbow. The elbow shows a higher percentage of limited ROM (47.0 %). The number of enlarged joints has a significant correlation with the VAS or elbow and knee ROM compared with the age or course of disease (P < 0.05). Severe elbow and knee lesions are important clinical features of KBD in adults younger than 50 years of age during a low incidence period. The number of enlarged joints can partially predict the VAS or ROM of elbow and knee and may be used for evaluating the patient's condition and function.

Genome-wide study identifies the regulatory gene networks and signaling pathways from chondrocyte and peripheral blood monocyte of Kashin-Beck disease

This investigation was designed to unravel gene networks in Kashin-Beck disease (KBD) and better identify target genes of KBD for gene therapy development. RNA was isolated separately from cartilage and peripheral blood samples of patients with KBD and healthy controls. Agilent 44K human whole-genome oligonucleotide microarrays were used to detect differentially expressed genes. Three significant canonical pathways and nine chondrocyte networks from chondrocytic gene expression profiles were screened using ingenuity pathway analysis (IPA), but only one network and no canonical pathways from peripheral blood monocytic gene profile were identified. Bak1, APAF-1, CASP6, IGFBP2, Col5a2 and TGFBI extracted from significant genes that involved in chondrocytic canonical pathways and networks may have closer relationship with the etiopathogenesis of KBD. Those genes may be potential targets for gene diagnosis and treatment. Six physiological functions were predominant and unique to the chondrocytic genes, whereas two were unique to peripheral blood monocytic genes. The identified genes may represent a source of potentially novel molecular targets, which may provide a better understanding of the molecular details in KBD pathogenesis and also provide useful pathways and network maps for the future research in osteochondrosis.

Histopathology of chondronecrosis development in knee articular cartilage in a rat model of Kashin-Beck disease using T-2 toxin and selenium deficiency conditions

The objective of this study is to observe pathogenic lesions of joint cartilages in rats fed with T-2 toxin under a selenium deficiency nutrition status in order to determine possible etiological factors causing Kashin-Beck disease (KBD). Sprague-Dawley rats were fed selenium-deficient or control diets for 4 weeks prior to their being exposed to T-2 toxin. Six dietary groups were formed and studied 4 weeks later, i.e., controls, selenium-deficient, low T-2 toxin, high T-2 toxin, selenium-deficient diet plus low T-2 toxin, and selenium-deficient diet plus high T-2 toxin. Selenium deficiencies were confirmed by the determination of glutathione peroxidase activity and selenium levels in serum. The morphology and pathology (chondronecrosis) of knee joint cartilage of experimental rats were observed using light microscopy and the expression of proteoglycans was determined by histochemical staining. Chondronecrosis in deep zone of articular cartilage of knee joints was seen in both the low and high T-2 toxin plus selenium-deficient diet groups, these chondronecrotic lesions being very similar to chondronecrosis observed in human KBD. However, the chondronecrosis observed in the rat epiphyseal growth plates of animals treated with T-2 toxin alone or T-2 toxin plus selenium-deficient diets were not similar to that found in human KBD. Our results indicate that the rat can be used as a suitable animal model for studying etiological factors contributing to the pathogenesis (chondronecrosis) observed in human KBD. However, those changes seen in epiphyseal growth plate differ from those seen in human KBD probably because of the absence of growth plate closure in the rat.

Environmental selenium in the Kaschin-Beck disease area, Tibetan Plateau, China

Now, there is a decreasing trend for the prevalence rate of Kaschin-Beck disease (KBD) in most parts of China, but the disease is still active and severe in the Tibetan Plateau for some reason. To further explore the role of selenium in the occurrence of KBD, We collected samples including drinking water, cultivated topsoil, Highland Barley grains, and tsamba in Rangtang County and Aba County, Sichuan Province and determined concentrations of selenium by Hydride Generation Atomic Fluorescence Spectrometry. Levels of selenium in the environment were analyzed in detail. Selenium in the soil-plant-food system and their relationship with prevalence rate of KBD were also discussed. The results indicate: (a) the levels of environmental selenium are very low and the study area belongs to a selenium-deficient ecological landscape; (b) the KBD becomes much more severe with decreasing environmental selenium under the selenium-deficient condition. Namely, the lower the environmental selenium is, the more severe the disease is; (c) soil selenium deficiency plays a critical role for the prevalence of local KBD, and more factors inducing selenium deficiency should be more concerned in the future.

An unusual phaeoid fungi: Ulocladium, as a cause of chronic allergic fungal sinusitis

Allergic fungal sinusitis (AFS) has been recognized as an important cause of chronic sinusitis commonly caused by Aspergillus spp. and various dematiaceous fungi like Bipolaris, Alternaria, Curvalaria, and etc. Ulocladium botrytis is a non pathogenic environmental dematiaceous fungi, which has been recently described as a human pathogen. Ulocladium has never been associated with allergic fungal sinusitis but it was identified as an etiological agent of AFS in a 35 year old immunocompetent female patient presenting with chronic nasal obstruction of several months duration to our hospital. The patient underwent FESS and the excised polyps revealed Ulocladium as the causative fungal agent.

Study on the effect of T-2 toxin combined with low nutrition diet on rat epiphyseal plate growth and development

The purpose of this study was to observe early lesions of rat epiphyseal plates and metaphysis caused by T-2 toxin and T-2 toxin combined with a low nutrition diet to determine possible pathogenic factors of Kashin-Beck disease (KBD). Ninety Wistar rats were divided into three groups. Group A was fed with a normal diet as control; group B was fed with a normal diet and T-2 toxin; and group C was fed with a low nutrition diet and T-2 toxin. The left knee specimens were collected, fixed in formaldehyde solution, stained by hematoxylin and eosin and Masson. After two weeks, the epiphyseal plate showed necrosis of chondrocytes in groups B and C. After four weeks, more obvious chondrocyte necrosis appeared. The positive rate of Lamellar necrosis in group C was significantly higher than that in groups B and A (P < 0.01). Metaphyseal trabecular bone showed sparse disorder and disruption in group C. T-2 toxin combined with a low nutrition diet could lead to more serious chondrocyte necrosis in the epiphyseal plate and disturb metaphyseal trabecular bone formation.

Effects of physical environment on the evolution of Kashin-Beck disease in Tibet

In previous studies we observed a proximo-distal gradient of lesion frequencies along the limb, with the distal joints being the most often affected. This suggests an associated effect of environmental factors on the most exposed joints. On a population of 820 children (mean age 13 years) of endemic areas distributed in groups of healthy and severity stages I to III of KBD (Kashin-Beck disease), the effects of different working activities were studied. Heavy work like that of a ploughman were compared to light physical work, e.g. school children, and exposure to cold and history of frostbite were also considered. The most severe stages, II and III, were present in 72% of the ploughman vs. 29% of the schoolchildren, 70% of the shepherds vs. 30% (p < 0.001) of the schoolchildren, and in 65% of the shepherds working in winter vs. 40% of those working in the other seasons (p < 0.001). In the group with history of frostbite, 58% present the severest stages vs. 40% without (p < 0.001). The results confirm a highly significant relation between microtrauma and cold and the severity of the KBD alterations.

Nutritional Epidemiology and Thyroid Hormone Metabolism

Severe iodine deficiency was the main cause of endemic goiter and cretinism. Most of the previously iodine-deficient areas are now supplemented, mainly with iodized salt. The geographical distribution of severe endemic areas has been progressively reduced, and at present, approximately 200 million people living in remote places are still at risk of severe iodine deficiency. International public health programs should be focused first on reaching these populations, and second on auditing and monitoring the operational work of supplementation programs. This second point is essential to prevent iodine-induced hyperthyroidism or interruptions of iodine supplement distribution, which could be catastrophic for the fetus and the young infant. Echography brings a complementary tool to clinical assessment of goiter by palpation. Inductively coupled plasma-mass spectrometry brings at least a definitive gold standard for iodine measurement and thyroid hormone measurement. Thiocyanate overload has been clearly documented as a goitrogen in Central Africa, and when associated with selenium deficiency, it may be included as risk factor for endemic myxedematous cretinism. Variable exposure to different environmental risk factors is likely the explanation of the variable distribution of two types of endemic cretinism (neurological and myxedematous), and the clinical overlap of the pathogeny of both syndromes is more important than previously described. It is possible that Kashin-Beck osteoarthropathy is another evanescent endemic disease that will disappear with the correction of iodine deficiency.