Characteristics and adsorption behavior of typical microplastics in long-term accelerated weathering simulation.

Microplastics can function as carriers in the environment, absorbing various toxins and spreading to diverse ecosystems. Toxins accumulated in microplastics have the potential to be re-released, posing a threat. In this study, two typical plastics, namely polyethylene (PE) and polystyrene (PS), along with the degradable plastic poly(butylene adipate-co-terephthalate) (PBAT), were subjected to a long-term ultraviolet alternating weathering experiment. The study investigated the variations in the weathering process and pollutant adsorption of microplastics of different particle sizes. Furthermore, the adsorption capacity of microplastics for various pollutants was assessed. The findings indicate that particle size significantly influences weathering, leading to variations in adsorption capacity. The weathered PE displays a higher adsorption capacity for azo dyes. Additionally, the adsorption capacity of PBAT for neutral red is double that of antibiotics. Importantly, the maximum adsorption capacity of PBAT for pollutants after aging is approximately 10 times greater than that of PE. Consequently, degradable plastics undergoing weathering in the natural environment may pose a higher ecological risk than traditional plastics.

NADPH and NAC synergistically inhibits chronic ocular hypertension-induced neurodegeneration and neuroinflammation through regulating p38/MAPK pathway and peroxidation.

Glaucoma, the leading cause of irreversible blindness worldwide, is characterized by neurodegeneration and neuroinflammation with retinal NAD/NADP and GSH decline. Nicotinamide adenine dinucleotide (NAD)/NAD phosphate (NADP) and glutathione (GSH) are two redox reducers in neuronal and glial metabolism. However, therapeutic strategies targeting NAD/NADP or GSH do not exert ideal effects, and the underlying mechanisms are still poorly understood. We assessed morphological changes in retinal ganglion cells (RGCs), the affected neurons in glaucoma, and Müller cells, the major glial cells in the retina, as well as the levels of phosphorylated p38 (p-p38) and Caspase-3 in glaucoma patients. We constructed a modified chronic ocular hypertensive rat model and an oxygen-glucose deprivation (OGD) cell model. After applying NADPH and N-acetylcysteine (NAC), a precursor to cysteine, the rate-limiting substrate in GSH biosynthesis, to cells, apoptosis, axonal damage and peroxidation were reduced in the RGCs of the NAC group and p-p38 levels were decreased in the RGCs of the NADPH group, while in stimulated Müller cells cultured individually or cocultured with RGCs, gliosis and p38/MAPK, rather than JNK/MAPK, activation were inhibited. The results were more synergistic in the rat model, where either NADPH or NAC showed crossover effects on inhibiting peroxidation and p38/MAPK pathway activation. Moreover, the combination of NADPH and NAC ameliorated RGC electrophysiological function and prevented Müller cell gliosis to the greatest extent. These data illustrated conjoined mechanisms in glaucomatous RGC injury and Müller cell gliosis and suggested that NADPH and NAC collaborate as a neuroprotective and anti-inflammatory combination treatment for glaucoma and other underlying human neurodegenerative diseases.

Development and material characteristics of glaucoma surgical implants.

Background: Glaucoma is the leading cause of irreversible blindness worldwide. The reduction of intraocular pressure has proved to be the only factor which can be modified in the treatment, and surgical management is one of the important methods for the treatment of glaucoma patients. Main text: In order to increase aqueous humor outflow and further reduce intraocular pressure, various drainage implants have been designed and applied in clinical practice. From initial Molteno, Baerveldt and Ahmed glaucoma implants to the Ahmed ClearPath device, Paul glaucoma implant, EX-PRESS and the eyeWatch implant, to iStent, Hydrus, XEN, PreserFlo, Cypass, SOLX Gold Shunt, etc., glaucoma surgical implants are currently undergoing a massive transformation on their structures and performances. Multitudinous materials have been used to produce these implants, from original silicone and porous polyethylene, to gelatin, stainless steel, SIBS, titanium, nitinol and even 24-carat gold. Moreover, the material geometry, size, rigidity, biocompatibility and mechanism (valved versus nonvalved) among these implants are markedly different. In this review, we discussed the development and material characteristics of both conventional glaucoma drainage devices and more recent implants, such as the eyeWatch and the new minimally invasive glaucoma surgery (MIGS) devices. Conclusions: Although different in design and materials, these delicate glaucoma surgical implants have widely expanded the glaucoma surgical methods, and improved the success rate and safety of glaucoma surgery significantly. However, all of these glaucoma surgical implants have various limitations and should be used for different glaucoma patients at different conditions.

Keratin8 Deficiency Aggravates Retinal Ganglion Cell Damage Under Acute Ocular Hypertension.

Purpose: Keratin 8/18 (KRT8/18), paired members of the intermediate filament family, have shown vital functions in regulating physiological activities more than supporting the mechanic strength for cells and organelles. However, the KRT8/18 presence in retinal ganglion cells (RGCs) and functions on neuroprotection in a mouse model of acute ocular hypertension (AOH) are unknown and worthy of exploration. Methods: We identified the existence of KRT8/18 in normal human and mouse retinas and primary RGCs. KRT8/18 levels were detected after AOH modeling. The adeno-associated virus (AAV) system was intravitreally used for selective KRT8 knockdown in RGCs. The histological changes, the loss and dysfunction of RGCs, and the gliosis in retinas were detected. The markers of cell apoptosis and MAPK pathways were investigated. Results: KRT8/18 existed in all retinal layers and was highly expressed in RGCs, and they increased after AOH induction. The KRT8 knockdown in RGCs caused no histopathological changes and RGC loss in retinas without AOH modeling. However, after the KRT8 deficiency, AOH significantly promoted the loss of whole retina and inner retina thickness, the reduction, apoptosis, and dysfunction of RGCs, and the glial activation. Besides, downregulated Bcl-2 and upregulated cleaved-Caspase 3 were found in the AOH retinas with KRT8 knockdown, which may be caused by the increased phosphorylation level of MAPK pathways (JNK, p38, and ERK). Conclusions: The KRT8 deficiency promoted RGC apoptosis and neurodegeneration by abnormal activation of MAPK pathways in AOH retinas. Targeting KRT8 may serve as a novel treatment for saving RCGs from glaucomatous injuries.

Analysis of macular microvasculature with optical coherence tomography angiography for migraine: A systematic review and meta-analysis.

Objective: This study aimed to evaluate the features of macular microvasculature with optical coherence tomography angiography (OCTA) among migraine patients. Methods: We systematically searched PubMed, Web of Science, Embase, and Cochrane Library for studies that evaluated the macular microvasculature of migraine patients. The weighted mean differences (WMDs) of the foveal avascular zone (FAZ), foveal superficial capillary plexus (SCP) vessel density (VD), parafoveal SCP VD, foveal deep capillary plexus (DCP) VD, and parafoveal DCP VD with 95% confidence intervals (CIs) among migraine with aura (MA) group, migraine without aura (MO) group, and healthy controls (HC) group were analyzed using a random-effect model. P < 0.05 was considered significant in statistical analyses. Publication bias was assessed using funnel plots and statistical tests (Egger's test and Begg's test). Results: Nine studies covering 675 individuals were enrolled in this meta-analysis ultimately. The FAZ of MA patients was not significantly different from HC (WMD = 0.04, 95% CI -0.00 to 0.09). However, the FAZ of MA was significantly larger than that of HC after correction of publication bias by trim and fill method (WMD = 1.03, 95% CI 0.99 to 1.08). The FAZ of MO patients was similar to that of HC (WMD = 0.03, 95% CI -0.00 to 0.07), while smaller than that of MA patients (WMD = 0.05, 95% CI 0.01 to 0.09). VD of the SCP, either in the foveal or parafoveal area, was not significantly different among the three groups. As for DCP, VD in MA patients was lower when compared with HC in the parafovea (WMD = -1.20, 95% CI -1.88 to -0.51). Conclusions: We found that there was a larger FAZ in MA compared with HC after adjusting for publication bias. The FAZ in MO was not significantly different from that in HC, but significantly lower than that in MA. There was no significant difference in either foveal or parafoveal VD of SCP among MA, MO, and HC participants, while the parafoveal VD of the DCP in MA was lower than that of the HC.

SHIP-1 affects herpetic simplex keratitis prognosis by mediating CD4+ T lymphocytes migration through PI3K signaling and transcription factor KLF2 in the cornea.

Herpetic simplex keratitis (HSK) mainly represents an immune cell-mediated, and more specifically, CD4+ T cell-orchestrated inflammatory response to virus invasion. The virus in infected corneas could be easily inhibited or hidden in the trigeminal ganglion using antiviral drugs, but the immune-related inflammation will last for a long time and lead to significant complications. In the present study, we found that the subconjunctival injection of SHIP-1 activator AQX1125 in mouse HSK model alleviated the corneal inflammatory and angiogenic responses, as well as promoted quicker recovery of the cornea, with significantly fewer infiltration of CD4+ T lymphocytes. Furthermore, using primary CD4+ T lymphocytes, we observed that by modulating PI3K signaling and the expression of transcription factors KLF2 and CCR7, SHIP-1 could significantly influence the migration of lymphocytes toward CCL19 and 21, which are the "exit cues" for cells to emigrate from inflammatory sites. Thus, we propose that the pharmacological SHIP-1 activation represents a new potential therapeutic approach to control HSK lesions, and its function on the CCR7-CCL19/21 biological axis may be a novel underlying mechanism for its anti-inflammatory action.

Degradation and adsorption behavior of biodegradable plastic PLA under conventional weathering conditions.

With the increasing pollution of plastics and the widespread use of polylactic acid (PLA), its weathering process in the natural environment needs to be studied. Hence, we investigated the characteristics of PLA under conventional weathering conditions and the adsorption behavior between PLA and tetracycline (TC). The results showed cracks and holes in the weathered PLA surface, an increase in oxygen-containing functional groups, and a 77.94 % decrease in contact angle, causing more amount of TC to be adsorbed. The maximum adsorption capacity of PLA for TC is approximately 3.5 times higher than before weathering due to multilayer physical adsorption. Nevertheless, the surface of the microplastics weathered by seawater did not change significantly. This work elucidates the weathering mechanism of biodegradable microplastics under abiotic conditions, thus correctly assessing the difference in natural and conventional degradability of biodegradable plastics.

Inhibiting multiple forms of cell death optimizes ganglion cells survival after retinal ischemia reperfusion injury.

Progressive retinal ganglion cells (RGCs) death that triggered by retinal ischemia reperfusion (IR), leads to irreversible visual impairment and blindness, but our knowledge of post-IR neuronal death and related mechanisms is limited. In this study, we first demonstrated that apart from necroptosis, which occurs before apoptosis, ferroptosis, which is characterized by iron deposition and lipid peroxidation, is involved in the whole course of retinal IR in mice. Correspondingly, all three types of RGCs death were found in retina samples from human glaucoma donors. Further, inhibitors of apoptosis, necroptosis, and ferroptosis (z-VAD-FMK, Necrostatin-1, and Ferrostatin-1, respectively) all exhibited marked RGC protection against IR both in mice and primary cultured RGCs, with Ferrostatin-1 conferring the best therapeutic effect, suggesting ferroptosis plays a more prominent role in the process of RGC death. We also found that activated microglia, Müller cells, immune responses, and intracellular reactive oxygen species accumulation following IR were significantly mitigated after each inhibitor treatment, albeit to varying degrees. Moreover, Ferrostatin-1 in combination with z-VAD-FMK and Necrostatin-1 prevented IR-induced RGC death better than any inhibitor alone. These findings stand to advance our knowledge of the post-IR RGC death cascade and guide future therapy for RGC protection.

Corneal in vivo Confocal Microscopy for Assessment of Non-Neurological Autoimmune Diseases: A Meta-Analysis.

Purpose: This study aimed to evaluate the features of corneal nerve with in vivo confocal microscopy (IVCM) among patients with non-neurological autoimmune (NNAI) diseases. Methods: We systematically searched PubMed, Web of Science, and Cochrane Central Register of Controlled Trials for studies published until May 2021. The weighted mean differences (WMDs) of corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), tortuosity, reflectivity, and beadings per 100 µm with a 95% CI between NNAI and control group were analyzed using a random-effects model. Results: The results showed 37 studies involving collective totals of 1,423 patients and 1,059 healthy controls were ultimately included in this meta-analysis. The pooled results manifested significantly decreased CNFL (WMD: -3.94, 95% CI: -4.77--3.12), CNFD (WMD: -6.62, 95% CI: -8.4--4.85), and CNBD (WMD: -9.89, 95% CI: -14--5.79) in NNAI patients. In addition, the NNAI group showed more tortuous corneal nerve (WMD: 1.19, 95% CI:0.57-1.81). The comparison between NNAI patients and healthy controls in beadings per 100 µm corneal nerve length was inconsistent. No significant difference was found in the corneal nerve fiber reflectivity between NNAI and the control group (WMD: -0.21, 95% CI: -0.65-0.24, P = 0.361). Conclusions: The parameters and morphology of corneal nerves observed by IVCM proved to be different in NNAI patients from healthy controls, suggesting that IVCM may be a non-invasive technique for identification and surveillance of NNAI diseases.

Risk factors and severity of keratoconus on the East Coast of China.

PURPOSE: This study aims to investigate the characteristics, potential risk factors and associated severity of keratoconus on the east coast of China. METHODS: In this case-control study, patients diagnosed with keratoconus were invited to fill in the online electronic questionnaire designed with the help of the App named WenJuanXing. Several questions like, sex, age of diagnosis and eye care habits were administered to each subject through this e-questionnaire. Corneal topographies at diagnosis taken from Pentacam were also collected. RESULTS: Totally 391 Chinese keratoconus outpatients were enrolled in this study, among which 159 patients were newly diagnosed. Only three patients (0.77%) had a positive family history of keratoconus. Atopy could be identified in 66.0% of our patients. A total of 357 patients (91.3%) mentioned the habit of eye rubbing, with 191 patients (48.8%) rubbing their eyes frequently. Patients with younger age at onset (p = 0.005), male sex (p = 0.042), frequent eye rubbing (p = 0.003) and smoke (p = 0.002) were found significantly associated with increased risk of acute hydrops. In newly diagnosed patients, 79.9% had the maximum keratometry (Kmax) more than 52D, with males and patients aged 21-30 being even more serious (p = 0.009; p = 0.005). Besides, in patients aged over 21, frequent eye rubbing was significantly associated with steeper Kmax and more severe astigmatism (all p < 0.05). CONCLUSION: Our results suggest that frequent eye rubbing is closely related to the severity of keratoconus in Chinese patients. Chinese keratoconus patients always had much serious disease condition at the time of diagnosis. Thus, increasing the publicity of keratoconus and advocating appropriate eye care habits are needed urgently in China. REGISTRATION: The research was retrospectively registered, and the trial registration number is ChiCTR1900021273, and the registration date is 2019/02/09.

Clinical efficacy comparison of low-temperature plasma radiofrequency ablation and Nd:YAG laser in treating recurrent acquired nasolacrimal duct obstruction.

To evaluate the effectiveness and safety of low-temperature plasma radiofrequency ablation (coblation) and Nd:YAG laser in treating recurrent nasolacrimal duct obstruction. A prospective study was performed on patients who agreed to be treated with coblation or Nd:YAG laser for recurrent nasolacrimal duct obstruction after failed lacrimal Nd:YAG laser combined with silicone intubation. The visual analogue scale (VAS) pain grade was assessed at baseline, immediately, and 3 and 7 days after surgery. The degree of watering, lacrimal passage irrigation, and complications were also evaluated 1 week and 1, 3, and 6 months after surgery. Ninety-five patients who met the criteria for recurrent nasolacrimal duct obstruction from February 2018 to February 2019 were included in this study, with 46 patients receiving coblation and 49 patients Nd:YAG laser. The intraoperative and postoperative (3 days after surgery) VAS pain grades of the patients who received coblation were significantly lower than those who received Nd:YAG laser (P < 0.001). The number of patients in the coblation group who achieved complete clinical relief (no epiphora symptoms with fluent lacrimal passage irrigation) was significantly larger than that in the lacrimal Nd:YAG laser group at 1, 3, and 6 months after surgery (P = 0.033, P = 0.006, P = 0.003, respectively). During the follow-up period, there were no unexpected complications in either group. Compared with Nd:YAG laser, coblation performed well in alleviating pain and maintaining sustained disease relief and may therefore be an alternative to conventional laser or dacryocystorhinostomy surgery in the management of recurrent nasolacrimal duct obstruction.

Clinical results of Intraductal Meibomian gland probing combined with intense pulsed light in treating patients with refractory obstructive Meibomian gland dysfunction: a randomized controlled trial.

BACKGROUND: This study aims to optimize the therapeutic regimen for refractory obstructive meibomian gland dysfunction (o-MGD) patients by combining intraductal meibomian gland probing (MGP) and intense pulsed light (IPL) to enhance their positive effects and reduce their limitations. METHODS: This randomized, assessor blind study includes 45 patients (90 eyes) with refractory o-MGD who were divided into 3 groups via allocation concealment: IPL (group I, received an IPL treatment course: 3 times at 3-week intervals), MGP (group II, received MGP one time), and combined MGP-IPL (group III, MGP first followed by an IPL treatment course). Standard Patient Evaluation of Eye Dryness score (SPEED), tear break-up time (TBUT), corneal fluorescein staining (CFS), meibum grade, and lid margin finding results were assessed at baseline, 3 weeks after final treatment for groups I and III, 3 and 12 weeks after MGP for group II. Six months after final treatment, the SPEED and willingness to receive any treatment again were also collected for all groups. Paired Wilcoxon, Mann-Whitney U with Bonferroni correction, and Kruskal-Wallis tests were used for data analysis. RESULTS: For all 3 groups, all previously mentioned indexes improved significantly following treatment (P<0.01). MGP-IPL was better than IPL and MGP in terms of post-treatment SPEED, TBUT, meibum grade, and lid telangiectasia (P<0.05/3). Furthermore, the MGP-IPL was better than IPL in terms of lid tenderness and better than MGP in terms of orifice abnormality (P< 0.05/3). Six months later, the SPEED for the MGP-IPL was also significantly lower than other groups (P<0.05/3). Moreover, no patients in the MGP-IPL group expressed the need to be treated again compared to 35.7% or 20% of patients in the IPL or MGP groups, respectively. CONCLUSIONS: Compared with IPL or MGP alone, the combination MGP-IPL produced best results in relieving all signs and symptoms and helping patients attain long-lasting symptom relief. TRIAL REGISTRATION: http://clinicaltrials.gov , ChiCTR1900021273 (retrospectively registered February 9, 2019).

Short-term results of acellular porcine corneal stroma keratoplasty for herpes simplex keratitis.

BACKGROUND: Corneal transplantation is a common surgical intervention for restoring vision loss due to corneal damages. However, for cultural reasons, there is a huge shortage of donor corneas in China. Acellular porcine corneal stromas (APCSs) can be used as corneal substitutes in lamellar keratoplasty for corneal ulcers. This study was conducted to analyze the results of APCS use for herpes simplex keratitis (HSK). METHODS: The study involved HSK patients who underwent keratoplasty with APCSs from February 2016 to October 2017 in the second affiliated hospital of Zhejiang University. Patient data were collected at 7 days, 1 month, 3 months, 6 months, and at the last follow-up (7-25 months) postoperative. The corneal transparency, neovascularization, visual acuity, and graft stability were observed. RESULTS: Thirteen patients with HSK including five patients with corneal perforation were included in this study, nine patients underwent deep anterior lamellar keratoplasty (DALK) and five perforation patients underwent double lamellar keratoplasty. There were nine men and four women with an average age of 62.5 ± 5.6 years old (ranging from 52 to 70 years old). The mean postoperative follow-up duration was 15.1 ± 5.8 months (ranging from 7 to 25 months). At the last visit, visual acuity improved in nine patients (69.2%) compared with preoperative (P = 0.008).The grafts of seven individuals (53.8%) were completely transparent or slightly opaque; their corneal transparency score had improved significantly compared with before the surgery (P = 0.010). Various degrees of neovascularization were present in 11 of the 13 patients (84.6%), most neovascularization gradually stabilized. Graft dissolution occurred in three eyes (23.1%) during the observation period, two underwent regrafting, the other one became stable after treatment. Three patients underwent second allograft transplantation, two of which encountered APCS graft dissolution and one of the patients requested a human donor allograft transplantation due to transparency issues despite the absence of adverse issues. CONCLUSION: Acellular porcine corneal stroma seems to be effective in the treatment of HSK and can be used in HSK with corneal perforation by using double lamellar keratoplasty in an emergency.

Clinical Analysis: Aqueous-Deficient and Meibomian Gland Dysfunction in Patients With Primary Sjogren's Syndrome.

Objective: To examine the time course of aqueous-deficient and meibomian gland dysfunction (MGD) in patients with primary Sjogren's Syndrome (pSS). Methods: This prospective study was conducted on pSS female patients in the Department of Rheumatism of the Second Affiliated Hospital, School of Medicine, Zhejiang University. The age-matched MGD female patients without pSS (non-SS-MGD) were recruited as MGD controls from the Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University. After providing written informed consent, the patients underwent an eye examination and completed an Ocular Surface Disease Index questionnaire that assessed the symptoms of dry eye disease. The subjects were evaluated using Schirmer I test (SIt), tear meniscus height (TMH), noninvasive keratographic break-up time (NIKBUT), corneal fluorescein staining (CFS), and meibomian gland evaluation (meibomian gland infrared, lid margin score, expressible meibomian glands number and the secretions quality). The patients were divided into two groups: early stage (≤3 years) and late stage (>3 years) according to their medical history of dry eye. The data were analyzed using SPSS 20.0. Results: There were 49 pSS and 52 non-SS-MGD female patients enrolled in this study from 1 January 2018 to 30 December 2018. There were no differences in age (49.38 ± 10.32 and 48.69 ± 13.57 years) and dry eye medical history (48.44 ± 40.16 and 47.79 ± 37.85 months) between the two groups. When the medical history was ≤3 years, the average SIt and TMH of the pSS patients were significantly smaller than those of the patients with MGD. However, the signs related to the MGD did not show a significant difference between the two groups. When the medical history was >3 years, both the SIt and TMH and the signs related to MGD in pSS group were significantly more severe than the MGD group. Conclusions: Our results demonstrated that 3 years may be an important time node for the dry eye development in pSS patients, before this, the lacrimal glands received a greater influence, and then the meibomian glands began to be greatly affected.

Efficacy and safety of laparoscopic bile duct exploration versus endoscopic sphincterotomy for concomitant gallstones and common bile duct stones: A meta-analysis of randomized controlled trials.

BACKGROUND: The purpose of this study was to compare the efficacy and safety of laparoscopic cholecystectomy (LC) plus laparoscopic common bile duct (CBD) stones exploration (LCBDE) with LC plus endoscopic sphincterotomy (EST) in the treatment of patients with gallstones and CBD stones. METHODS: The authors searched PubMed, Web of Science, and Embase to identify relevant studies. Risk ratios (RRs) were pooled to compare stone clear, retained stone, conversion to other procedures, and complications. Weighted mean differences (WMDs) were pooled to compare operative time, and length of hospital stay. A fixed-effects model or random-effects model was used to pool the estimates, according to the heterogeneity among the included studies. RESULTS: A total of 11 randomized controlled trials (RCTs) involving 1663 patients were included in this meta-analysis. The pooled estimate suggested that LC-LCBDE had comparable effects with LC-EST in terms of CBD stone clear rate (RR = 1.02, 95% CI: 0.95, 1.09; P = .583), retained stones rate (RR = 1.27, 95% CI: 0.51, 3.19; P = .607), and length of hospital stay (WMD = -0.96 days, 95% CI: -2.20, 0.28). In addition, LC-LCBDE was associated with significantly higher conversion rate (RR = 1.59, 95% CI: 1.08, 2.35; P = .019) and less operative time (WMD = -11.55 minutes, 95% CI: -16.68, -6.42; P < .001) than LC-EST. The incidence of complications was not significant difference between the 2 surgical approaches (RR = 1.07, 95% CI: 0.86, 1.34; P = .550). CONCLUSION: Based on the current evidence, both LC-LCBDE and LC-EST were highly effective in detecting and removing CBD stones and were equivalent in complications. However, our results might be biased by the limitations. Large-scale well-designed RCTs are needed to confirm our findings.

[Alteration of thromboxane A2 and prostacyclin levels in rats with obstructive jaundice and the effect of salviae miltiorrhizae on them].

OBJECTIVE: To observe the alteration of plasma levels of thromboxane A2 (TXA2) and prostacyclin (PGI2) as well as changes of microcirculation in renal cortex of obstructive jaundice model rats, and to study the effect of Radix Salviae miltiorrhizae (SM) on them. METHODS: SD rats were randomly divided into three groups: the sham operation group (A), the common bile duct ligation model group (B), and the SM treated model group (C). Their blood plasma TXA2/PGI2 ratio (T/P), blood levels of urea nitrogen (BUN) and creatinine (Cr) were determined respectively in batches (8 rats from each group) on the 3 rd, 7th and 10th day, their capillary caliber (CC) in renal cortex was measured at the same time points using WX-9 type microcirculation microscope. RESULTS: Compared with Group A, T/P was higher and CC was smaller in Group B at all the time points. Levels of BUN and Cr increased on day 7 and day 10 after modeling (P<0.05), and they were increasing markedly along with the elongation of the obstructive time (P<0.05). As compared with Group B, T/P was lower and CC was expanded in Group C, with levels of BUN and Cr lowered on day 10 (P<0.05). CONCLUSION: T/P elevation and renal microcirculation obstacle are the important factors for inducing renal injury in obstructive jaundice, and SM shows a protective effect on kidney against the injury.