[Molding matrix formulation of hot-melt pressure-sensitive adhesive plaster of personalized traditional Chinese medicine preparations].

This study aims to optimize the matrix formulation for the hot-melt pressure-sensitive adhesive plaster of personalized traditional Chinese medicine(TCM) preparations and verify the applicability of the formulation. The central composite design in JMP Pro 16.1.0 was employed to optimize the dosages of styrene-isoprene-styrene triblock copolymer(SIS), hydrogenated petroleum resin, and lightweight liquid paraffin, with the fine powder of Yipifang as the model drug(drug loading of 10%) and the sensory score and objective evaluation as the comprehensive evaluation indicators. The quality evaluation system of hot-melt pressure-sensitive adhesive plaster of personalized TCM preparations was established. The applicability of the optimized matrix formulation of hot-melt pressure-sensitive adhesive plaster was verified with 16 TCM preparations for external application. Furthermore, the applicability of the matrix formulation was investigated with different drug loadings. The general molding matrix formulation was SIS∶hydrogenated petroleum resin∶lightweight liquid paraffin 3∶3∶5. The optimized matrix formulation showed good molding properties and high quality scores for 16 TCM preparations and were suitable for the plastering of finely powdered decoction pieces with a loading capacity of 10% to 30%. The results suggest that the optimized matrix formulation has good applicability and is suitable for TCM preparations. The findings lay a foundation for the application and promotion of the hot-melt pressure-sensitive adhesive plasters of personalized TCM preparations.

Effect of Walking Exercise and Intestinal Cleansing Interval on Bowel Preparation Quality, a Single-Blind, Randomized Controlled Trial.

BACKGROUND AND AIMS: High-quality intestinal preparation could promote intestinal cleanliness and lead to more accurate diagnosis, which patients will benefit from. This study aimed to explore the effectiveness of walking exercise and intestinal cleansing interval in bowel preparation before colonoscopy. METHODS: A randomized controlled single blind study was conducted during August 2021 to February 2022. Patients requiring colonoscopy were randomly divided into three groups: 0 step, 5000 steps or 10,000 steps during the intestinal preparation. Participants took the same intestinal cleansing drugs 4-6 h prior to the procedure: 2L-dose polyethylene glycol (PEG). RESULTS: A total of 300 patients were enrolled in the experiment (100 patients per group), and the baseline information of the three groups was close. The BBPS of right (0-step group vs 5,000-step group vs 10,000-step group: 1.78 ± 0.65 vs 1.88 ± 0.54 vs 2.36 ± 0.69, p < 0.001), transverse (0-step group vs 5,000-step group vs 10,000-step group: 2.09 ± 0.78 vs 2.18 ± 0.61 vs 2.59 ± 0.71, p < 0.001) and left (0-step group vs 5,000-step group vs 10,000-step group: 2.01 ± 0.91 vs 2.24 ± 0.59 vs 2.51 ± 0.60, p < 0.001) colon in 10,000-step group were significantly higher than others, respectively. And we also drew the same conclusion in the aspect of ADR. The adverse events and patients' satisfaction had no differences between the two groups. Moreover, intestinal cleansing interval (< 5.12 h) was only effective in BBPS of right colon (p < 0.001) and left colon (p = 0.039). CONCLUSIONS: This study suggested that participants took 10,000-step walking exercise and took PEG 5.12 h prior to the procedure were effective in routine pre-procedure cleanout for standard colonoscopy. NAME OF REGISTRY: Effect of starting time of bowel cleansing and walking exercise after bowel cleansing on bowel preparation: A prospective randomized controlled study. REGISTRATION NUMBER: ChiCTR2100049214.

A rare case of pemphigus vulgaris disguised as a malignant gingival ulcer.

BACKGROUND: Pemphigus vulgaris (PV) is a kind of rare and severe autoimmune bullous disease. In this case, the specificity of oral PV lies in the clinical manifestations of a single palatal ulcer, and no blisters were found in the oral mucosa. This case provides a powerful reference for dentists diagnosing and treating oral PV with atypical clinical presentations. CASE PRESENTATION: A 54 years old female patient presented with a non-healing palatal gingival ulcer for over three months. By histopathological H&E staining and the direct immunofluorescence (DIF) test, the final diagnosis was oral PV. After topical glucocorticoid therapy, the affected area was cured. CONCLUSIONS: In patients with prolonged erosion of the skin or oral mucosa, even if complete blisters are not visible, the physician should consider autoimmune bullous diseases and pay attention to avoid diagnostic defects.

Enzymatic preparation of hydrophobic biomass with one-pot synthesis and the oil removal performance.

Oil pollution is causing deleterious damage to aquatic ecosystems and human health. The utilization of agricultural waste such as corn stalk (CS) to produce biosorbents has been considered an ecofriendly and efficient approach for removing oil. However, most previous studies focused on the modification of the whole CS, which is inefficient due to the heterogeneity of CS. In this study, corn stalk pith (CP), which has excellent amphipathic characteristics, was selected to prepare a high-efficiency oil sorbent by grafting dodecyl gallate (DG, a long-chain alkyl) onto CP surface lignin via laccase mediation. The modified biomass (DGCP) shows high hydrophobicity (water contact angle = 140.2°) and superoleophilicity (oil contact angle = 0°) and exhibits a high oil sorption capacity (46.43 g/g). In addition, DGCP has good stability and reusability for adsorbing oil from the aqueous phase. Kinetic and isotherm models and two-dimensional correlation spectroscopy integrated with FTIR analyses revealed that the main sorption mechanism involves the H-bond effect, hydrophobic effect and van der Waals force. This work provides an ecofriendly method to prepare oil sorbents and new insights into the mechanisms underlying the removal of spilled oil from wastewater.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review. / 上颌侧切牙重度畸形舌侧沟多学科联合治疗1ä¾‹å¹¶æ–‡çŒ®å¤ä¹ .

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Food emulsifier polysorbate 80 promotes the intestinal absorption of mono-2-ethylhexyl phthalate by disturbing intestinal barrier.

Di-2-ethylhexyl phosphate (DEHP) and its main toxic metabolite mono-2-ethylhexyl phthalate (MEHP) are the typical endocrine disrupting chemicals (EDCs) and widely affect human health. Our previous research reported that synthetic nonionic dietary emulsifier polysorbate 80 (P80, E433) had the promotional effect on the oral absorption of DEHP in rats. The aim of this study was to explore its mechanism of promoting oral absorption, focusing on the mucus barrier and mucosal barrier of the small intestine. A small molecule fluorescent probe 5-aminofluorescein-MEHP (MEHP-AF) was used as a tracker of MEHP in vivo and in vitro. First of all, we verified that P80 promoted the bioavailability of MEHP-AF in the long-term and low-dose exposure of MEHP-AF with P80 as a result of increasing the intestinal absorption of MEHP-AF. Afterwards, experimental results from Western blot, qPCR, immunohistochemistry, and immunofluorescence showed that P80 decreased the expression of proteins (mucus protein mucin-2, tight junction proteins claudin-1 and occludin) related to mucus barrier and mucosal barrier in the intestine, changed the integrity of intestinal epithelial cell, and increased the permeability of intestinal epithelial mucosa. These results indicated that P80 promoted the oral absorption of MEHP-AF by altering the intestinal mucus barrier and mucosal barrier. These findings are of great importance for assessing the safety risks of some food emulsifiers and clarifying the absorption mechanism of chemical pollutants in food, especially for EDCs.

Oral lichen planus induced by long-term use of antimicrobials for recurrent aphthous ulcer: A case report and literature review. / é•¿æœŸä½¿ç”¨æŠ—èŒè¯ç‰©æ²»ç–—å¤å‘æ€§å£è ”æºƒç–¡å¼•èµ·å£è ”æ‰å¹³è‹”è—“1ä¾‹å¹¶æ–‡çŒ®å¤ä¹ .

The precise etiology of oral lichen planus (OLP) is still unclear, but the existing evidence suggests that drug intake, virus infection, fungal infection, psychological disorders, and immunodeficiency are closely associated with the pathogenesis of OLP. We report a case of OLP accompanied with candidiasis induced by long-term use of antimicrobials for recurrent aphthous ulcer (RAU) and update the literature, to discuss the possible association between OLP and misuse of antimicrobials, and to inform general dentists and pharmacists the importance for practice with optimal antimicrobial stewardship. In this case, a 42-year-old man presented to Xiangya Stomatological Hospital with white reticular patterns spreading in the oral cavity for almost 1 year. He was diagnosed with OLP via histopathological examination. He had a 5-year history of RAU which occurred every 1-2 months, and he was given antimicrobials ingested or injected whenever the ulcers came up. Satisfactory treatment results were obtained by stopping the abuse of antimicrobials and local antifungal therapy. Meanwhile, the exacerbation and alleviation of OLP was closely related to the administration of antimicrobials. Combined with literature review, antimicrobial might contribute to the development of OLP by inducing candidiasis, a common side-effect of misuse of antimicrobials. Considering the seriousness of antimicrobial resistance and opportunistic infection, dentists should prescribe antimicrobials judiciously according to guidelines and evidence-based indications. Appropriate prescribing of antimicrobials is a professional responsibility to all dentists.

Treating periodontitis-a systematic review and meta-analysis comparing ultrasonic and manual subgingival scaling at different probing pocket depths.

BACKGROUND: Mechanical plaque removal has been commonly accepted to be the basis for periodontal treatment. This study aims to compare the effectiveness of ultrasonic and manual subgingival scaling at different initial probing pocket depths (PPD) in periodontal treatment. METHODS: English-language databases (PubMed, Cochrane Central Register of Controlled Trials, EMBASE, Medline, and ClinicalTrials.gov, by January, 2019) were searched. Weighted mean differences in primary outcomes, PPD and clinical attachment loss (CAL) reduction, were estimated by random effects model. Secondary outcomes, bleeding on probing (BOP), gingival recession (GR), and post-scaling residual dental calculus, were analyzed by comparing the results of each study. The quality of RCTs was appraised with the Cochrane Collaboration risk of bias tool. The GRADE approach was used to assess quality of evidence. RESULTS: Ten randomized controlled trials were included out of 1434 identified. Initial PPD and follow-up periods formed subgroups. For 3-months follow-up: (1) too few shallow initial pocket studies available to draw a conclusion; (2) the heterogeneity of medium depth studies was so high that could not be merged to draw a conclusion; (3) deep pocket studies showed no statistical differences in PPD and CAL reduction between ultrasonic and manual groups. For 6-months follow-up: (1) too few shallow initial PPD studies to draw a conclusion; (2) at medium pocket depth, PPD reduction showed manual subgingival scaling better than ultrasound. No statistical differences were observed in CAL reduction between the two approaches; (3) for deep initial PPD studies, both PPD and CAL reduction showed manual subgingival scaling better. GR results indicated no statistical differences at medium and deep initial pocket studies between the two methods. BOP results showed more reduction at deep pocket depths with manual subgingival scaling. No conclusion could be drawn about residual dental calculus. CONCLUSION: When initial PPD was 4-6 mm, PPD reduction proved manual subgingival scaling was superior, but CAL results showed no statistical differences between the two means. When initial PPD was ≥6 mm, PPD and CAL reductions suggested that manual subgingival scaling was superior.

Release of glucose repression on xylose utilization in Kluyveromyces marxianus to enhance glucose-xylose co-utilization and xylitol production from corncob hydrolysate.

BACKGROUND: Lignocellulosic biomass is one of the most abundant materials for biochemicals production. However, efficient co-utilization of glucose and xylose from the lignocellulosic biomass is a challenge due to the glucose repression in microorganisms. Kluyveromyces marxianus is a thermotolerant and efficient xylose-utilizing yeast. To realize the glucose-xylose co-utilization, analyzing the glucose repression of xylose utilization in K. marxianus is necessary. In addition, a glucose-xylose co-utilization platform strain will facilitate the construction of lignocellulosic biomass-utilizing strains. RESULTS: Through gene disruption, hexokinase 1 (KmHXK1) and sucrose non-fermenting 1 (KmSNF1) were proved to be involved in the glucose repression of xylose utilization while disruption of the downstream genes of cyclic AMP-protein kinase A (cAMP-PKA) signaling pathway or sucrose non-fermenting 3 (SNF3) glucose-sensing pathway did not alleviate the repression. Furthermore, disruption of the gene of multicopy inhibitor of GAL gene expression (KmMIG1) alleviated the glucose repression on some nonglucose sugars (galactose, sucrose, and raffinose) but still kept glucose repression of xylose utilization. Real-time PCR analysis of the xylose utilization related genes transcription confirmed these results, and besides, revealed that xylitol dehydrogenase gene (KmXYL2) was the critical gene for xylose utilization and stringently regulated by glucose repression. Many other genes of candidate targets interacting with SNF1 were also evaluated by disruption, but none proved to be the key regulator in the pathway of the glucose repression on xylose utilization. Therefore, there may exist other signaling pathway(s) for glucose repression on xylose consumption. Based on these results, a thermotolerant xylose-glucose co-consumption platform strain of K. marxianus was constructed. Then, exogenous xylose reductase and xylose-specific transporter genes were overexpressed in the platform strain to obtain YHY013. The YHY013 could efficiently co-utilized the glucose and xylose from corncob hydrolysate or xylose mother liquor for xylitol production (> 100 g/L) even with inexpensive organic nitrogen sources. CONCLUSIONS: The analysis of the glucose repression in K. marxianus laid the foundation for construction of the glucose-xylose co-utilizing platform strain. The efficient xylitol production strain further verified the potential of the platform strain in exploitation of lignocellulosic biomass.

Colonization Characteristics of Bacterial Communities on Plastic Debris Influenced by Environmental Factors and Polymer Types in the Haihe Estuary of Bohai Bay, China.

The colonization characteristics of bacterial communities on microplastics or plastic debris (PD) have generated great concern in recent years. However, the influence of environmental factors and polymer types on the formation of bacterial communities on PD in estuarine areas is less studied. To gain additional insights, five types of PD (polyvinyl chloride, polypropylene, polyethylene, polystyrene, and polyurethane) were exposed for three-time periods (two weeks, four weeks, and six weeks) in the Haihe Estuary. 16S rRNA gene sequencing was used to identify the bacterial communities on PD, in seawater, and in sediment samples. The results indicate that the average growth rate of a biofilm is affected by nutrients (total nitrogen and total phosphorus) and salinity. Furthermore, salinity is the primary factor affecting bacterial diversity of the colonies on PD. In addition, genera of bacteria show selectivity toward the PD polymer type and tend to colonize their preferred substrate. Compared with seawater and sediment, PD could be carriers for enrichment of Vibrio in the estuarine environment with salinity ≥26 (± 2‰), which might increase the ecological risk of PD in marine environments.

The potential therapeutic roles of dental pulp stem cells in spinal cord injury.

Spinal cord injury (SCI) can lead to serious functional disorders, which have serious impacts on patients and society. The current traditional treatments of SCI are not effective the injured spinal cord is difficult to repair and regenerate. In recent years, stem cell transplantation for the treatment of SCI has been a hot research topic. Dental pulp stem cells have strong abilities of self-renewal and multi-directional differentiation, and have been applied for tissue engineering and regenerative medicine. And dental pulp stem cells have certain advantages in neuro-regenetation, bringing new hope to biotherapy for SCI. This article reviews the characteristics of dental pulp stem cells and their research progress in the treatment of SCI.

Comparative Clinical Evaluation of Trapezoidal, Envelope, and Tunnel Type Coronally Advanced Flap in the Treatment of Gingival Recession: A Network Meta-Analysis of Randomized Clinical Trials.

This study evaluated the efficacy of trapezoidal coronally advanced flap (tCAF), envelope coronally advanced flap (eCAF), and coronally advanced tunnel flap (TUN) in treating gingival recession (GR) through a network meta-analysis. Eligible articles from the PubMed, Embase, and Cochrane Library databases published up to September 2020 were selected to identify randomized controlled trials (RCTs) on tCAF, eCAF, and TUN treatments. Sample size, treatment time, and outcome measures including complete root coverage (CRC), root coverage esthetic score (RES), and other data were extracted from the article, and integrated analysis was conducted. In total, 10 RCTs met the inclusion criteria, involving 310 patients. Direct meta-analysis showed no significant differences in CRC among the three surgical methods; A significant difference was seen for RES, with TUN worse than tCAF (weighted mean difference: -0.73; 95% CI: -1.44, -0.02; P = .045). The network meta-analysis showed no statistical significance in the cross-comparison of tCAF, eCAF, and TUN. However, eCAF had the most significant effect on improving CRC (SUCRA = 69.2) and RES (SUCRA = 85.0). eCAF has the best prognosis in the treatment of GR, followed by tCAF and TUN. This may influence the surgeon's treatment choice, as eCAF may be more effective in root coverage procedures.

Oral submucous fibrosis induced by graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

Graft-versus-host disease (GVHD) is one of the most common and serious complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). About 45%∼83% of patients develop GVHD in the oral cavity. There has no medical records of oral submucous fibrosis (OSF) induced by GVHD after allo-HSCT, which should be brought to the attention of dentists.

Hermansky-Pudlak syndrome type 2: A rare cause of severe periodontitis in adolescents-A case study.

Background and aims: Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by oculocutaneous albinism (OCA) and platelet storage pool deficiency. The HPS-2 subtype is distinguished by neutropenia, and little is known about its periodontal phenotype in adolescents. AP3B1 is the causative gene for HPS-2. A 13-year-old Chinese girl presented to our department suffering from gingival bleeding and tooth mobility. Her dental history was otherwise unremarkable. Suspecting some systemic diseases as the underlying cause, the patient was referred for medical consultation, a series of blood tests, and genetic tests. In this case study, periodontal status and mutation screening of one HPS-2 case are presented. Methods: Blood analysis including a complete blood count (CBC) and glycated hemoglobin levels were measured. Platelet transmission electron microscopy (PTEM) was performed to observe the dense granules in platelets. Whole-exome sequencing (WES) and Sanger sequencing were performed to confirm the pathogenic variants. Results: A medical diagnosis of HPS-2 was assigned to the patient. Following the medical diagnosis, a periodontal diagnosis of "periodontitis as a manifestation of systemic disease" was assigned to the patient. We identified novel compound heterozygous variants in AP3B1 (NM_003664.4: exon7: c.763C>T: p.Q255*) and (NM_003664.4: exon1: c.53_56dup: p.E19Dfs*21) in this Chinese pedigree with HPS-2. Conclusion: This case study indicates the importance of periodontitis as a possible indicator of underlying systemic disease. Systemic disease screening is needed when a young patient presents with unusual, severe periodontitis, as the oral condition may be the first of a systemic abnormality. Our work also expands the spectrum of AP3B1 mutations and further provides additional genetic testing information for other HPS-2 patients.

Inhibition of Smad signaling is implicated in cleft palate induced by all-trans retinoic acid.

The effect of all-trans retinoic acid (atRA) on palatal fusion and the underlying mechanisms were investigated using organ culture. Compared with control group, the atRA-treated group (1 µM and 5 µM) had more medial edge epithelium (ME) remaining within the midline epithelial seam (MES). At 10 µM atRA, the opposing shelves were not in contact at the culture end (72 h). Cell death detection by TUNEL and laminin immunohistochemistry demonstrated that atRA (5 µM) induced apoptosis in mesenchyme and inhibited degradation of basal lamina within MES. Notably, migration and apoptosis of ME cells and degradation of basal lamina within MES markedly represented vehicle control palatal shelves in culture. Additionally, apoptosis was not detected in mesenchyme of control palatal shelves. Immunoblotting analysis revealed that Smad2 and Smad3 were endogenously activated and expression of Smad7 was inhibited during the fusion process. In contrast, atRA treatment abrogated phosphorylation of Smad2 and Smad3 and inducible expression of Smad7 in ME. From these data, it is assumed that inhibition of Smad pathway by atRA in ME may play a critical role in abrogation of the ME cell apoptosis and degradation of the basal laminin, which might contribute to failure of palatal fusion.

Dental caries and associated factors among Chinese children and adolescents: A protocol for systematic review and meta-analysis.

BACKGROUND: Dental caries is a common disease under the action of many factors. Dental caries may occur in all age groups, among which children and adolescents are at high risk of dental caries. Early identification of the risk factors of dental caries is very important for clinical staff to prevent and intervene as soon as possible and reduce the incidence of dental caries. Although Chinese scholars have studied and summarized the risk factors of dental caries in children and adolescents, the conclusions are different. Therefore, in this study, meta-analysis was used to summarize the risk factors of dental caries in Chinese children and adolescents, and to explore the characteristics of high-risk groups of dental caries, so as to provide reference for early detection and prevention of dental caries. METHODS: Medical specialty databases like PubMed, Embase, Cochrane Library, Web of Science, China Biology Medicine Database, China National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang Database were consistently and exhaustively searched. According to the method of evidence-based medicine, the inclusion and exclusion criteria were established, and the meta-analysis of all eligible research results was carried out by using Review Manager 5.3 software. RESULTS: We will disseminate the findings of this systematic review and meta-analysis via publications in peer-reviewed journals. CONCLUSIONS: Our study was carried out to estimate the pooled prevalence of dental caries and its associated factors among Chinese children and adolescents. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/RA9D6.

The Hippo pathway: a renewed insight in the craniofacial diseases and hard tissue remodeling.

The Hippo pathway plays an important role in many pathophysiological processes, including cell proliferation and differentiation, cell death, cell migration and invasion. Because of its extensive functions, Hippo pathway is closely related to not only growth and development, but also many diseases, including inflammation and cancer. In this study, the role of Hippo pathway in craniofacial diseases and hard tissue remodeling was reviewed, in attempting to find new research directions.

Colonization characteristics of bacterial communities on plastic debris: The localization of immigrant bacterial communities.

The unique characteristics of bacterial communities on plastic debris and microplastics in the environment have been widely studied in recent years. However, due to the randomness of sampling, it is hard to identify whether the unique characteristics of bacterial communities on plastic debris is due to the plastics as substrate itself, or the accumulation and transportation by plastics. Therefore, the ecological effects of bacterial communities on plastic debris, including the species invasion, are still not clear. To investigate such issue, we took the Haihe Estuary (Tianjin, China) as an example, and designed a strategy to sample and redeploy randomly collected environmental plastic debris for 6 weeks, thus the variation of bacterial communities on plastic debris could be assessed. At the same time, commercial experimental plastic debris was used as the control group to monitor the growth of local bacterial communities on plastics in the cultivation environment. Our study discussed the bacterial communities on the environmental plastic debris from three aspects, including colonization characteristics, taxonomic analysis and molecular metabolism estimation. We found that the bacterial communities on environmental plastic debris tended to show local characteristics, which were less affected by their original characteristics. Therefore, the results reminded us that the ecological risks of bacterial communities on plastics, which were brought by the transportation of plastic debris in the environment, may not be as serious as it was expected previously.

CT-guided needle biopsy through mandibular area for the diagnosis of nasopharyngeal carcinoma in the parapharyngeal space.

BACKGROUND AND OBJECTIVE: The primary submucous type of nasopharyngeal carcinoma (NPC) or the recurrent NPC in the parapharyngeal space is difficult to be diagnosed histologically by conventional biopsy because of the obstruction of the surrounding structures. This study was performed to evaluate the needle biopsy approach through the madibular area into the parapharyngeal space under the guidance of computed tomography (CT) for NPC. METHODS: Between July 6, 2005 and October 23, 2009, a total of 6 patients were enrolled into the study. Two patients with cervical lymph node metastasis were clinically suspicious of NPC according to their clinical manifestations. However, no cancer cell could be found by repeated nasopharyngeal biopsies followed by histologic examinations. The other 4 patients were diagnosed with recurrent NPCs by magnetic resonance imaging (MRI) or/and positron emission tomography (PET)-CT scan, showing tumors in the parapharyngeal spaces in 3 patients and enlarged retropharyngeal lymph node in 1 patient. The CT-guided puncture was performed through the mandibular skin and the cutting needle biopsy was taken at the parapharyngeal space focus. RESULTS: All the cutting needle biopsies of projected locations have been performed safely. Finally, all the 7 specimens met the requirement of pathologic diagnosis and the cases were all confirmed histologically to be NPCs. The main complication was mild ache at the puncture point. No blood vessel or nerve was injured and no patient needed special treatment. CONCLUSIONS: The CT-guided puncture biopsy of the parapharyngeal space through the mandibular area is simple and feasible. It can be an additional option for routine nasopharyngeal biopsy.

Heavy metals contamination of sedimentary microplastics in Hong Kong.

This is the first study of heavy metals (As, Zn, Cd, Ni, Fe, Mn, Cu) contamination of microplastics on sandy beaches in Hong Kong. Three study sites are located in the eastern waters (Pak Lap Wan, Stanley Bay, Tung Lung Chau) and the other three in the western waters (Tai Pai Tsui, Ha Pak Nai, Shui Hau Wan). The three most abundant types of microplastics were polyethylene (42.2%), polypropylene (23.3%) and polystyrene (19.5%). The median concentration of Fe (302 mg kg-1) was the highest and followed by Zn (19.6 mg kg-1) and Mn (18.6 mg kg-1). Very low concentrations of Cu (0.89 mg kg-1), Ni (0.15 mg kg-1), As (