[Analysis of the serum bile acid profile to facilitate diagnosis and differential diagnosis of NA(+)-taurocholate cotransporting polypeptide deficiency].

Objective: This study focuses on Na(+)-taurocholate cotransporting polypeptide (NTCP) deficiency to analyze and investigate the value of the serum bile acid profile for facilitating the diagnosis and differential diagnosis. Methods: Clinical data of 66 patients with cholestatic liver diseases (CLDs) diagnosed and treated in the Department of Pediatrics of the First Affiliated Hospital of Jinan University from early April 2015 to the end of December 2021 were collected, including 32 cases of NTCP deficiency (16 adults and 16 children), 16 cases of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD), 8 cases of Alagille syndrome, and 10 cases of biliary atresia. At the same time, adult and pediatric healthy control groups (15 cases each) were established. The serum bile acid components of the study subjects were qualitatively and quantitatively analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry. The data were plotted and compared using statistical SPSS 19.0 and GraphPad Prism 5.0 software. The clinical and bile acid profiles of children with NTCP deficiency and corresponding healthy controls, as well as differences between NTCP deficiency and other CLDs, were compared using statistical methods such as t-tests, Wilcoxon rank sum tests, and Kruskal-Wallis H tests. Results: Compared with the healthy control, the levels of total conjugated bile acids, total primary bile acids, total secondary bile acids, glycocholic acid, taurocholic acid, and glycochenodeoxycholic acid were increased in NTCP deficiency patients (P < 0.05). Compared with adults with NTCP deficiency, the levels of total conjugated bile acids and total primary bile acids were significantly increased in children with NTCP deficiency (P < 0.05). The serum levels of taurochenodeoxycholic acid, glycolithocholate, taurohyocholate, and tauro-α-muricholic acid were significantly increased in children with NTCP deficiency, but the bile acid levels such as glycodeoxycholic acid, glycolithocholate, and lithocholic acid were decreased (P < 0.05). The serum levels of secondary bile acids such as lithocholic acid, deoxycholic acid, and hyodeoxycholic acid were significantly higher in children with NTCP deficiency than those in other CLD groups such as NICCD, Alagille syndrome, and biliary atresia (P < 0.05). Total primary bile acids/total secondary bile acids, total conjugated bile acids/total unconjugated bile acids, taurocholic acid, serum taurodeoxycholic acid, and glycodeoxycholic acid effectively distinguished children with NTCP deficiency from other non-NTCP deficiency CLDs. Conclusion: This study confirms that serum bile acid profile analysis has an important reference value for facilitating the diagnosis and differential diagnosis of NTCP deficiency. Furthermore, it deepens the scientific understanding of the changing characteristics of serum bile acid profiles in patients with CLDs such as NTCP deficiency, provides a metabolomic basis for in-depth understanding of its pathogenesis, and provides clues and ideas for subsequent in-depth research.

[Efficacy of arteriovenous argatroban versus heparin flush anticoagulation after cardiovascular surgery].

Objective: To compare the effects of arteriovenous argatroban and heparin flushes on platelet count and assess the occurrence of heparin-induced thrombocytopenia (HIT) and other complications in patients undergoing cardiovascular surgeries. Methods: A single-center, prospective randomized control study was conducted. Patients who underwent cardiovascular surgery at Fuwai Hospital, Chinese Academy of Medical Sciences from March to December 2019 were randomly divided into the argatroban group (250 ml normal saline plus 2.5 mg of argatroban) and the heparin group (250 ml normal saline plus 10 mg of heparin). Platelet count, hemorrhage, and thrombosis were assessed. The 4T scores of HIT, the incidences of HIT and other complications were also evaluated. Results: A total of 491 patients (307 males and 184 females) were included in the study, with a mean age of (52.3±13.7) years. There were 245 cases in the argatroban group and 246 cases in the heparin group, respectively. There was no statistically significant difference in the preoperative platelet count between the argatroban and heparin groups [198.0 (161.0, 248.0)×109/L vs 194.0 (157.2, 243.8)×109/L, P=0.498]. Likewise, there were no statistically significant differences in the platelet count between the argatroban and heparin groups at 12 h, 1 day, and 5 days after operation [127.0 (100.0, 154.0)×109/L vs 121.5 (90.2, 149.0)×109/L, 126.0 (97.0, 162.0)×109/L vs 123.5 (88.0, 151.0)×109/L, 168.0 (130.0, 215.0) ×109/L vs 161.0 (101.0, 210.5)×109/L] (repeated measures ANOVA between groups: F=3.327, P=0.069; time comparison: F=532.523, P<0.001; time interaction between groups: F=0.675, P=0.512). The proportion of 4T scores of medium and high scores (≥4)[9.8% (24/245) vs 10.6% (26/246), P=0.777] and incidence of HIT antibody positive [1.63% (4/245) vs 1.63% (4/246), P=0.726] were similar between argatroban group and the heparin group. Mechanical ventilation time was shorter in the argatroban group than that in the heparin group [13.0 (11.0, 21.0) vs 15.5 (12.0, 21.0) h, P=0.020]. Conclusion: Compared with heparin, routine management with argatroban for arteriovenous flush in patients undergoing cardiovascular surgery does not affect the HIT incidence.

[Association of thrombocytopenia with mortality after surgery in patients with Standford type A aortic dissection].

Objective: To evaluate the association of thromboytopenia with mortality of Standford type A aortic dissection after cardiopulmonary bypass surgery. Methods: Total of 498 patients with Standford type A aortic dissection after surgery in Fuwai Hospital of the Chinese Academy of Medical Sciences from May 2017 to December 2018 were collected retrospectively. There were 350 males and 148 females, with a mean age of (51.7±12.0) years. The patients were divided into thrombocytopenia group (platelet count<75×1015/L, n=178) and normal platelet group (platelet count≥75×1015/L, n=320) according to the lowest platelet count within 72 hours after surgery. The perioperative in-hospital mortality and related complications were calculated by univariate and multivariate logistic regression analysis. The primary endpoint was in-hospital mortality, and the secondary endpoints included secondary thoracotomy, pneumonia, postoperative continuous renal replacement therapy, paraplegia, heart failure, length of hospital stay and intensive care unit (ICU) stay time. Results: The morbidity of thrombocytopenia after Standford type A aortic dissection surgery was 35.7% (178/498). Univariate logistic regression analysis showed that postoperative thrombocytopenia was significantly associated with in-hospital mortality and 7 secondary endpoints (P<0.05). Multivariate logistic regression analysis showed thrombocytopenia after aortic dissection surgery was significantly associated with increased postoperative mortality (OR=12.57, 95%CI: 2.26-69.93, P=0.004), secondary thoracotomy (OR=6.21, 95%CI: 1.31-29.46, P=0.022), continuous renal replacement therapy (OR=7.51, 95%CI: 2.53-22.34, P<0.001), paraplegia (OR=23.99, 95%CI: 1.47-392.21, P=0.026), heart failure (OR=4.71, 95%CI: 1.19-18.62, P=0.027) and longer ICU stay time (OR=1.86, 95%CI: 1.11-3.12, P=0.019). Conclusions: Thrombocytopenia after Standford type A aortic dissection after cardiopulmonary bypass surgery (the lowest platelet count within 72 hours) is strongly associated with postoperative in-hospital mortality. Trying to avoid the factors related to thrombocytopenia can prevent more complications at the same time.

[Application of sutureless integrated stented graft in patients with aortic dissection].

Objective: To preliminarily investigate effectiveness and safety of sutureless integrated stented graft (SIS graft) on aortic dissection patients undergoing surgeries. Methods: In October 2019, 2 patients with aortic dissection were treated by SIS graft in Shenzhen Fuwai Hospital. Data of the operations and follow-up were recorded. Results: Patient 1 (male, 42 years old) was treated with aortic sinus repair, ascending aortic replacement, total arch replacement combined with frozen elephant trunk implantation. Time of cardiopulmonary bypass and circulatory arrest was 81 minutes and 9.5 minutes,respectively. The lowest nasopharynx temperature was 27.3 ℃. This patient was followed up for 10 months and no postoperative complication was found. Six-month postoperative aortic CT angiography (CTA) revealed SIS graft was patent and no anastomosis fistula or stent leakage occurred. True lumen of stented area was full-filled and false lumen disappeared. Incomplete false lumen thrombosis was seen in un-stented thoracic aorta, but no progressive aortic enlargement appeared. Patient 2 (male, 61 years old) was treated with ascending aortic replacement, ascending aorta to right femoral artery bypass graft, total arch replacement combined with frozen elephant trunk implantation. Time of cardiopulmonary bypass and circulatory arrest was 77 minutes and 7 minutes,respectively. The lowest nasopharynx temperature was 27.3 ℃. This patient was also followed up for 10 months and was free of postoperative complications. Six-month postoperative aortic CTA revealed SIS graft was patent and there was no anastomosis fistula or stent leakage. Perfusion of true lumen in thoracic aorta and branches of abdominal aorta improved significantly and complete false lumen thrombosis could be seen in thoracic aorta. Progressive aortic enlargement was not detected. Conclusion: Application of SIS graft can reduce circulatory arrest time and avoid deep hypothermia, which will decrease risks of postoperative complications, and this graft can simplify surgery procedure. However, further clinical trial for effectiveness and safety of SIS graft should be applied.

Influence of LincRNA-p21 on acute lung injury in sepsis.

OBJECTIVE: Acute lung injury (ALI) is one of the most serious complications of sepsis and remains refractory. It is of great significance to discuss the pathogenesis of acute lung injury in sepsis and look for more effective drugs for treatment. The purpose of this study was to investigate the role of LincRNA-p21 on acute lung injury in sepsis. MATERIALS AND METHODS: Lung histology was detected by HE staining to evaluate sepsis-induced ALI model in rats. The miRNA expression of LincRNA-p21 in septic model in vivo and in vitro was detected by RT-qPCR. Cell apoptosis, inflammatory responses and oxidative stress were detected to uncover the influence of LincRNA-p21 on LPS-induced septic model in vitro. RESULTS: The expression of LincRNA-p21 was significantly increased in septic model in vivo and in vitro. Cell apoptosis, inflammatory responses and oxidative stress were alleviated by LincRNA-p21 interference in LPS-treated BEAS-2B cells. CONCLUSIONS: All the results in the current study proved that LincRNA-p21 interference could alleviate the acute lung injury in septic model. It raised the conclusion that LincRNA-p21 may act as a novel regulator in the pathological process and a potential therapeutic target in sepsis-induced ALI.

Exaptation of two ancient immune proteins into a new dimeric pore-forming toxin in snails.

The Membrane Attack Complex-Perforin (MACPF) family is ubiquitously found in all kingdoms. They have diverse cellular roles, however MACPFs with pore-forming toxic function in venoms and poisons are very rare in animals. Here we present the structure of PmPV2, a MACPF toxin from the poisonous apple snail eggs, that can affect the digestive and nervous systems of potential predators. We report the three-dimensional structure of PmPV2, at 17.2 Å resolution determined by negative-stain electron microscopy and its solution structure by small angle X-ray scattering (SAXS). We found that PV2s differ from nearly all MACPFs in two respects: it is a dimer in solution and protomers combine two immune proteins into an AB toxin. The MACPF chain is linked by a single disulfide bond to a tachylectin chain, and two heterodimers are arranged head-to-tail by non-covalent forces in the native protein. MACPF domain is fused with a putative new Ct-accessory domain exclusive to invertebrates. The tachylectin is a six-bladed ß-propeller, similar to animal tectonins. We experimentally validated the predicted functions of both subunits and demonstrated for the first time that PV2s are true pore-forming toxins. The tachylectin "B" delivery subunit would bind to target membranes, and then the MACPF "A" toxic subunit would disrupt lipid bilayers forming large pores altering the plasma membrane conductance. These results indicate that PV2s toxicity evolved by linking two immune proteins where their combined preexisting functions gave rise to a new toxic entity with a novel role in defense against predation. This structure is an unparalleled example of protein exaptation.

De novo transcriptome assembly of the marine gastropod Reishia clavigera for supporting toxic mechanism studies.

The intertidal whelk Reishia clavigera is commonly used as a biomonitor of chemical contamination in the marine environment along Western Pacific region, and as a model for mechanistic studies of organotin-mediated imposex development. However, limited genomic resources of R. clavigera have restricted its role for the investigation of molecular mechanisms of such endocrine disruptions. This study, therefore, aimed to establish tissue-specific transcriptomes of the digestive gland, gonad, head ganglia, penis and the remaining body part of the male and female R. clavigera. By combining the results, a global transcriptome was obtained. A total of 578,134,720 high-quality filtered reads were obtained using Illumina sequencing. The R. clavigera transcriptome comprised of 38,466 transcripts and 32,798 unigenes with predicted open reading frames. The average length of transcripts was 1,709bp with N50 of 2,236bp. Based on sequence similarity searches against public databases, 28,657 transcripts and 24,403 unigenes had at least one BLAST hit. There were 17,530 transcripts and 14,897 unigenes annotated with at least one Gene Ontology (GO) term. Moreover, 5,776 transcripts and 5,137 unigenes were associated with 333 Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways. The numbers of unigenes were similar among the five target tissues and between sexes, but tissue-specific expression profiles were revealed by multivariate analyses. Based on the functional annotation, putative steroid hormone-associated unigenes were identified. In particular, we highlighted the presence of steroid hormone receptor homologues that could be the targets for mechanistic studies of the organotin-mediated imposex development in marine gastropods. This newly generated transcriptome assembly of R. clavigera provides a valuable molecular resource for ecotoxicological and environmental genomic studies.

Effects of hypoxia on biofilms and subsequently larval settlement of benthic invertebrates.

Biofilms on submerged surfaces are important in determining larval settlement of most marine benthic invertebrates. We investigated if exposure of biofilms to hypoxia would alter the larval settlement pattern and result in a shift in benthic invertebrate community structure in the field. Biofilms were first exposed to hypoxia or normoxia in laboratory microcosms for 7 days, and then deployed in the field for another 7 days to allow for larval settlement and recruitment to occur. Using terminal-restriction fragment length polymorphism of the 16S rRNA gene, this study showed that hypoxia altered the biofilm bacterial community composition, and the difference between the hypoxic and normoxic treatments increased with the time of exposure period. This study also demonstrated significantly different benthic invertebrate community structures as a result of biofilm exposure to hypoxia and that the hypoxic and normoxic treatments were dominated by Hydroides sp. and Folliculina sp., respectively.

Acute hypoxic exposure affects gamete quality and subsequent fertilization success and embryonic development in a serpulid polychaete.

Hypoxia likely compromises the reproductive success of those marine organisms carrying out external fertilization because their gametes and embryos are inevitably exposed to the external environment. Hydroides elegans, a dominant serpulid polychaete in Hong Kong waters, can spawn throughout the year but the number of recruits drops during summer when hypoxia commonly occurs. This study attempted to explain such observation by investigating the gamete quality, including sperm motility, egg size, complexity and viability, after 1-h hypoxic exposure (1 mg O2 l(-1)). In addition, how gamete quality affects fertilization success and embryonic development was examined. After 1-h hypoxic exposure, sperm motility was significantly reduced, compromising fertilization success. Although the eggs remained viable, more malformed embryos and retarded embryonic development were observed. We interpreted that the harmful effect of hypoxia on embryonic development was attributed to the teratogenicity and induced oxidative stress, ultimately causing the reduction in recruitment during summer.

De novo transcriptomic profile in the gonadal tissues of the intertidal whelk Reishia clavigera.

The intertidal whelk Reishia clavigera (formerly named as Thais clavigera) is one of the most sensitive species to organotin-associated imposex. However, the limited information on mRNA transcriptome of the species has restricted the molecular investigation on such endocrine disruption. By means of Illumina sequencing, we obtained a global de novo transcriptome from the gonadal tissues of both male and female R. clavigera, with 197,324 assembled transcripts and 151,684 condensed non-redundant transcripts. Blast hit results from the NCBI's non-redundant molluscan database showed that 28,948 transcripts were successfully annotated with significant matches at an e-value of ⩽1e(-6). Among them, 1108 transcripts were assigned a well-defined gene ontology term. As the first transcriptomic study on the gonadal tissues of R. clavigera, this study has enhanced the information of mRNA transcriptome on this species and will thus facilitate mechanistic studies of chemical contaminants (e.g., organotins) on this common biomonitor species.

QCD and strongly coupled gauge theories: challenges and perspectives.

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.

Hypoxia induces abnormal larval development and affects biofilm-larval interaction in the serpulid polychaete Hydroides elegans.

Hydroides elegans, a worldwide fouling polychaete, can spawn throughout the year, but its recruitment drops during summer when hypoxia prevails. Here, the influence of hypoxia on larval development and settlement of H. elegans was investigated. Results showed that larval development was compromised at 1mg O2 l(-1) with a lower proportion of competent larvae and a higher proportion of malformed larvae, probably due to reduction in clearance rate. Regarding larval settlement, although most of the larvae were reluctant to settle at 1mg O2 l(-1), regardless of the biofilm nature, they settled quickly within 24h in response to the resumption of dissolved oxygen. Furthermore, only about 5% of the larvae settled on the biofilms developed under hypoxia, regardless of dissolved oxygen levels of the seawater. The delayed larval development and potential alteration of biofilm nature owing to hypoxia explained why the recruitment of H. elegans declines during summer.

Effect of parental hypoxic exposure on embryonic development of the offspring of two serpulid polychaetes: Implication for transgenerational epigenetic effect.

Sperm production and motility, fecundity, and egg size, complexity and viability of serpulid polychaetes Hydroides elegans and Hydroides diramphus after 2-week treatment to hypoxia (2 mg O2 l(-1)) was compared with those under normoxia (6 mg O2 l(-1)). Despite reduced fecundity, the effect of parental hypoxic exposure on gamete quality was not discernible for both species. However, regardless of their subsequent dissolved oxygen environment, eggs spawned by H. elegans after hypoxic exposure were found to have lower fertilization success, slower embryonic development and a significantly higher yield of malformed embryos than those with a parental normoxic treatment. In contrast, neither fertilization success nor rate of embryonic development was affected for H. diramphus. The results implied that hypoxia was a potential stress reducing the recruitment of H. elegans through non-adaptive epigenetic effect, whereas H. diramphus was a more tolerant species to survive hypoxic events.

De novo assembly of the transcriptome of an invasive snail and its multiple ecological applications.

Studying how invasive species respond to environmental stress at the molecular level can help us assess their impact and predict their range expansion. Development of markers of genetic polymorphism can help us reconstruct their invasive route. However, to conduct such studies requires the presence of substantial amount of genomic resources. This study aimed to generate and characterize genomic resources using high throughput transcriptome sequencing for Pomacea canaliculata, a nonmodel gastropod indigenous to Argentina that has invaded Asia, Hawaii and southern United States. De novo assembly of the transcriptome resulted in 128,436 unigenes with an average length of 419 bp (range: 150-8556 bp). Many of the unigenes (2439) contained transposable elements, showing the existence of a source of genetic variability in response to stressful conditions. A total of 3196 microsatellites were detected in the transcriptome; among 20 of the randomly tested microsatellites, 10 were validated to exhibit polymorphism. A total of 15,412 single-nucleotide polymorphisms (SNPs) were detected in the ORFs. LC-MS/MS analysis of the proteome of juveniles revealed 878 proteins, of which many are stress related. This study has demonstrated the great potential of high throughput DNA sequencing for rapid development of genomic resources for a nonmodel organism. Such resources can facilitate various molecular ecological studies, such as stress physiology and range expansion.

Algal-derived organic matter as precursors of disinfection by-products and mutagens upon chlorination.

Algal-derived organic materials (including algal cells, hydrophilic and hydrophobic proteins) from Chlamydomonas sp. (a common green alga in local reservoirs), were chlorinated in the laboratory (20 °C, pH 7, Cl(2)/DOC ratio of 20 mg Cl(2) mg(-1)). Levels of disinfection by-products and mutagenicity (via Salmonella T100 mutation assay, -S9) over 2 h of chlorination time were determined. The hydrophilic proteins were more effective precursors of chloroform (35.9 µmol L(-1) at 120 min), 35 times greater than that from the hydrophobic proteins; whereas the hydrophobic proteins were more potent precursors of direct-acting mutagens (maximum level of 50.1 rev µL(-1) at 30 s) than the hydrophilic proteins (maximum level of 3.38 rev µL(-1) at 60 min). The mutagenicity of the chlorinated solutions generally reached a peak level shortly after chlorination and then declined afterwards, a pattern different from that of chloroform generation. The results indicate that algal hydrophilic proteins, containing low aromaticity and difficult to be removed via coagulation/flocculation, are important chloroform precursors. It is also suggested that hydrophobic organic intermediates with low molecular weight formed during chlorination may serve as the direct-acting mutagens.

Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: implication for human health.

Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies.

Acute and chronic toxicities of tributyltin to various life stages of the marine polychaete Hydroides elegans.

Experiments were performed to determine the acute and chronic toxicities of tributyltin (TBT) (nominal concentrations) to polychaete Hydroides elegans. Firstly, static tests were performed to examine the lethal effect of TBT on five life stages of H. elegans. The 48-h LC(50) (95% CI) for the eggs, 2-cells, trochophores, juveniles and adults was 0.18 (0.15-0.20), 0.97 (0.77-1.23), 2.36 (2.11-2.65), 2.86 (2.63-3.12) and 4.36 (4.04-4.71) microg TBT l(-1), respectively. Secondly, a 17-d static renewal chronic test was conducted to study sensitivity of the early development (egg to juvenile) to TBT. The survivorship, percent settlement and time to reach settlement were significantly reduced at 0.01 microg TBT l(-1). Effects of TBT on the juvenile growth and maturation were also studied through a 44-d chronic test. Lower survivorship and reduced tube growth were observed only at >or= 1 microg TBT l(-1), however, only H. elegans exposed to or= 0.1 microg TBT l(-1). Our results indicate that the early development of H. elegans is highly sensitive to TBT and this polychaete can be routinely employed as a test organism for both acute and chronic ecotoxicity bioassays in tropical and subtropical regions such as southern China.

Ecological risk assessments of endocrine disrupting organotin compounds using marine neogastropods in Hong Kong.

As active ingredients of anti-fouling paints that are widely used on ship hulls, organotin compounds, in particular tributyltin (TBT), are well-known endocrine disruptors causing sex changes in marine organisms and widespread in coastal waters and sediments worldwide. In this study, a comprehensive ecological risk assessment (ERA) of organotins was conducted in Hong Kong waters through determining the imposex status, sex ratio and tissue burdens of these compounds in the neogastropods, Thais clavigera and Thais luteostoma collected from 29 coastal sites. We also investigated the historical trend of organotin effects on these gastropods, and performed a probabilistic ERA based on tissue burden of TBT in the animals. Our results demonstrated that imposex indices were positively correlated with the body burden of organotins in the gastropods. Across all sites, the sex ratio (female:male) decreased significantly with increasing imposex levels or tissue burden of organotins, implying that such pollutants can result in a male-biased population, potentially leading to local extinction in extreme cases. Based on the ERA, 5.4% of all populations of T. clavigera are at risk due to exposure to TBT; the risks include growth inhibition, impairment of immune functions and reduced fitness. Seriously impacted areas included Aberdeen, Repulse Bay, Butterfly Beach, Mui Wo and Ha Mei Wan. A comparison with historical data revealed that there had been some improvement in the areas with low marine traffic, and distant from the major harbour/port. This could partly be due to the restriction on the use of TBT on small vessels (<25m in length) since 1992. Nevertheless, the organotin contamination still remains severe in areas with high marine traffic or adjacent to large harbours/ports. In particular, the situation in the northeastern waters of Hong Kong has been getting worst since 1996 that is probably associated with the rapid development of the cargo container port at Yantian in China.