Low-molecular-weight heparin and preeclampsia—does the sword cut both ways?Three case reports and review of literature

BACKGROUND Low-molecular-weight heparins(LMWH)are the most commonly used anticoagulants during pregnancy.It is considered to be the drug of choice due to its safety in not crossing placenta.Considering the beneficial effect in the improvement of microcirculation,prophylactic application of LMWH in patients with preeclampsia became a trend.However,the bleeding risk related with LMWH in preeclampsia patients has seldomly been evaluated.This current study aimed to identify the potential risks regarding LMWH application in patients with preeclampsia.CASE SUMMARY Herein we present a case series of three pregnant women diagnosed with preeclampsia on LMWH therapy during pregnancy.All the cases experienced catastrophic hemorrhagic events.After reviewing the twenty-one meta-analyses,the bleeding risk related with LMWH seems ignorable.Only one study analyzed the bleeding risk of LMWH and found a significantly higher risk of developing PPH in women receiving LMWH.Other studies reported minor bleeding risks,none of these were serious enough to stop LMWH treatment.Possibilities of bleeding either from uterus or from intrabdominal organs in preeclampsia patients on LMWH therapy should not be ignored.Intensive management of blood pressure even after delivery and homeostasis suture in surgery are crucial.CONCLUSION Consideration should be given to the balance between benefits and risks of LMWH in patients with preeclampsia.

Low-molecular-weight fucoidan inhibits the proliferation of melanoma via Bcl-2 phosphorylation and PTEN/AKT pathway

Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-Helicobacter pylori properties.However,the effects of low-molecular-weight fucoidan(LMW-F)on melanoma cell lines and three dimensional(3D)cell culture models are not well understood.This study aimed to investigate the effects of LMW-F on A375 human melanoma cells and cryopreserved biospecimens derived from patients with advanced melanoma.Ultrasonic wave was used to fragment fucoidan derived from Fucus vesiculosus into smaller LMW-F.MTT and live/dead assays showed that LMW-F inhibited cell proliferation in both A375 cells and patientderived melanoma explants in a 3D-printed collagen scaffold.The PTEN/AKT pathway was found to be involved in the anti-melanoma effects of fucoidan.Western blot analysis revealed that LMW-F reduced the phosphorylation of Bcl-2 at Thr 56,which was associated with the prevention of anti-apoptotic activity of cancer cells.Our findings suggested that LMW-F could enhance anti-melanoma chemotherapy and improve the outcomes of patients with melanoma resistance.

Hyaluronan对创面组织中生长因子含量的影响

目的探讨Hyaluronan对创面愈合组织中的生长因子含量的影响。方法将小型猪背部的去中厚皮片创面(共128个)分为实验组和自身对照组,在实验组创面上分别应用0.5%、1.0%及2.0%的Hyaluronan,测定术后第3、7、14、28天各创面愈合组织中的bFGF及EGF含量。结果Hyaluronan能促进创面愈合组织中EGF含量的增加,同时能相对抑制愈合组织中bFGF的增加。结论Hyaluronan通过对创面组织中的生长因子水平的调控,在促进创面愈合的同时能减轻瘢痕的形成。

Low-Molecular-Weight Aliphatic Acids in Soils Incubated with Plant Residues Under Different Moisture Conditions

Incubation experiments were conducted to investigate the dynamics of low- molecufar-weight aliphatic acids in two andosols with and without plant materials. Results showed that amount of low- molecular-weight aliphatic acids in soils alone varied considerably with water regime under which the soil was incubated,duration of incubation and soil organic matter content, ranging from 257-860 pmol kg-1 soil I of which 19%～33% was in free state. Incorporation of plant materials increased greatly both the amount and number of members of low- molecular- weight aliphaticacidst and also the proporticn of low-molec "far-weight aliphatic acids occurred in free state. Generally, among these aliphatic acids detected, acetic, propionic, glyoxalic and formic acids were predominant.

Dissolution of Aluminum in Variably Charged Soils as Affected by Low-Molecular-Weight Organic Acids

Low-molecular-weight （LMW） organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and A1 detoxification. In this research, a batch experiment was conducted to examine the effects of LMW organic acids on dissolution of aluminum in two variably charged soils, an Ultisol and an Oxisol. The results showed that the LMW organic acids enhanced the dissolution of A1 in the two investigated soils in the following order： citric 〉 oxalic 〉 malonic 〉 malic 〉 tartaric 〉 salicylic 〉 lactic 〉 maleic. This was generally in agreement with the magnitude of the stability constants for the Al-organic complexes. The effects of LMW organic acids on Al dissolution were greater in the Ultisol than in the Oxisol as compared to their controls. Also, the accelerating effects of citric and oxalic acids on dissolution of A1 increased with an increase in pH, while the effects of lactic and salicylic acids decreased. Additionally, when the organic acid concentration was less than 0.2 mmol L-I, the dissolution of A1 changed Iittle with increase in acid concentration. However, when the organic acid concentration was greater than 0.2 mmol L^-1,the dissolution of A1 increased with increase in acid concentration. In addition to the acid first dissociation constant and stability constant of Al-organic complexes, the promoting effects of LMW organic acids on dissolution of A1 were also related to their sorption-desorption equilibrium in the soils.

Antioxidation Activities of Low-Molecular-Weight Gelatin Hydrolysate Isolated from the Sea Cucumber Stichopus japonicus

Gelatin extracted from the body wall of the sea cucumber （Stichopus japonicus） was hydrolyzed with flavourzyme. Low-molecular-weight gelatin hydrolysate （LMW-GH） of 700-- 1700 Da was produced using an ultrafiltration membrane bioreaetor system. Chemiluminescence analysis revealed that LMW-GH scavenges high free radicals in a concentration-dependent manner; IC50 value for superoxide and hydroxyl radicals was 442 and 285 μgmL-1, respectively. LMW-GH exhibited excellent inhibitory characteristics against melanin synthesis and tyrosinase activity in B16 cells. Furthermore, LMW-GH notably increased in- traeellular glutathione （GSH）, which in turn suppressed melanogenesis. LMW-GH performs antioxidation activity, holding the potential of being used as a valuable ingredient in function foods, cosmetics and pharmaceuticals or nutriceuticals.

Golgi localization and dynamics of hyaluronan binding protein 1 (HABP1/p32/C1QBP) during the cell cycle

Hyaluronan binding protein 1 (HABP1) is a negatively charged multifunctional mammalian protein with a unique structural fold. Despite the fact that HABP1 possesses mitochondrial localization signal, it has also been localized to other cellular compartments. Using indirect immunofluorescence, we examined the sub-cellular localization of HABP1 and its dynamics during mitosis. We wanted to determine whether it distributes in any distinctive manner after mitotic nuclear envelope disassembly or is dispersed randomly throughout the cell. Our results reveal the golgi localization of HABP1 and demonstrate its complete dispersion throughout the cell during mitosis. This distinctive distribution pattern of HABP1 during mitosis resembles its ligand hyaluronan, suggesting that in concert with each other the two molecules play critical roles in this dynamic process.

Overexpression of a Foreign Bt Gene in Cotton Affects the Low-Molecular-Weight Components in Root Exudates

Most research in the past using genetically modified crops (GM crops) has focused on the ecological safety of foreign gene (i.e., the gene flow), gene products (for example, Bt (Bacillus thuringiensis) protein), and the safety of transgenic food for humans. In this study, changes in both the species and amounts of low-molecular-weight components in cotton (Gossypium hirsutum L.) root exudates after foreign Bt gene overexpression were investigated under different nutritional conditions. Transgenic cotton containing Bt (Bt-cotton), supplemented with all the mineral nutrients, secreted more organic acids than the wild-type cotton (WT). When nitrogen was removed from the full-nutrient solution, the amount of organic acids secretion of Bt-cotton was lesser than that of WT. The roots of the transgenic cotton secreted lesser amounts of amino acids and soluble sugars than the WT roots in the full-nutrient solution. Deficiencies of P and K caused a large increase in the total amino acid and soluble sugar secretions of both Bt-cotton and WT, with larger increases observed in Bt-cotton. Because transferring the foreign Bt gene into cotton can result in alterations in the components of the root exudates, with the effect varying depending on the nutritional status, the cultivation of genetically modified crops, such as Bt-cotton, in soil environments should be more carefully assessed, and the possible effects as a result of the alterations in the root exudate components should be considered.

Determination of Hyaluronan by Spectroscopic Methods

Hyaluronan is a kind of polysaccharide with high molecule weight, hs structure is relatively complicated and tertiary structure exists among the HA molecules when reaching to o certain solution concentration . FT- IR spectrum has been acquired to shou the groups and their ascription in HA. The results of FT-IR spectrum in this essay accords well with that issued by ASTM. As to the newly appearing absorption peaks, sensible explanation has been given, In ADDITION , Ramon spectrum has been employed as a proof for the result of the FT-IR spectnun. Based on the preliminary acknowledge of the functional groups in HA, circular dichroism of the material has also been explored.

Clinical effectiveness of a pneumatic compression device combined with low-molecular-weight heparin for the prevention of deep vein thrombosis in trauma patients:A single-center retrospective cohort study

BACKGROUND:To investigate the clinical effectiveness of a pneumatic compression device(PCD)combined with low-molecular-weight heparin(LMWH)for the prevention and treatment of deep vein thrombosis(DVT)in trauma patients.METHODS:This study retrospectively analyzed 286 patients with mild craniocerebral injury and clavicular fractures admitted to our department from January 2016 to February 2020.Patients treated with only LMWH served as the control group,and patients treated with a PCD combined with LMWH as the observation group.The incidence of DVT,postoperative changes in the visual analogue scale(VAS)score,and coagulation function were observed and compared between the two groups.Excluding the influence of other single factors,binary logistic regression analysis was used to evaluate the use of a PCD in the patient’s postoperative coagulation function.RESULTS:After excluding 34 patients who did not meet the inclusion criteria,252 patients were were included.The incidence of DVT in the observation group was significantly lower than that in the control group(5.6%vs.15.1%,χ^(2)=4.605,P<0.05).The postoperative VAS scores of the two groups were lower than those before surgery(P<0.05).The coagulation function of the observation group was significantly higher than that of the control group,with a better combined anticoagulant effect(P<0.05).There were no significant differences between the two groups in preoperative or postoperative Glasgow Coma Scale scores,intraoperative blood loss,postoperative infection rate,or length of hospital stay(P>0.05).According to logistic regression analysis,the postoperative risk of DVT in patients who received LMWH alone was 1.764 times that of patients who received LMWH+PCD(P<0.05).The area under the receiver operating characteristic(AUROC)curve of partial thromboplastin time(APTT)and platelet(PLT)were greater than 0.5,indicating that they were the influence indicators of adding PCD to prevent DVT.Excluding the influence of other variables,LMWH+PCD effectively improved the coagulation function of patients.CONCLUSIONS:Compared with LMWH alone,LMWH+PCD could improve blood rheology and coagulation function in patients with traumatic brain injury and clavicular fracture,reduce the incidence of DVT,shorten the length of hospital stay,and improve the clinical effectiveness of treatment.

Attenuation of corneal neovascularization by topical low-molecular-weight heparin-taurocholate 7 without bleeding complication

AIM：To investigate the antiangiogenic effects and safety of topically administered low-molecular-weight heparintaurocholate 7（LHT7） on corneal neovascularization（CoNV）.METHODS：Twenty-four Sprague-Dawley rats were randomly distributed into four groups of six rats each.The central corneas were cauterized using a silver/potassium nitrate solution.From 2d after cauterization,12.5 mg/mL（low LHT7 group） or 25 mg/mL（high LHT7group） LHT7 was topically administered three times daily;12.5 mg/mL bevacizumab was topically administered as positive control（bevacizumab） group,with normal saline（NS） administered as negative control（NS group）.The corneas were digitally photographed to calculate the CoNV percentage from the neovascularized corneal area at 1 and 2wk.RESULTS：The 4 study groups did not have different CoNV percentages at 1wk after injury（P〉0.05）.However,the low LHT,high LHT,and bevacizumab groups had significantly lower CoNV percentages than the NS group at 2wk（all P〈0.05）.No significant differences in CoNV percentage were found among the low LHT,high LHT,and bevacizumab groups（all P〉0.05）.All groups except the NS group had lower CoNV percentages at 2wk postinjury than the levels observed at 1wk（all P〈0.05）.CONCLUSION：Topically-administered LHT7 inhibited CoNV without complication after chemical cauterization in the rat.

Incidence of pocket hematoma after electrophysiological device placement：dual antiplatelet therapy versus low-molecular-weight heparin regimen

Background Given the increasing number of patients who require dual antiplatelet （DAP） therapy and electrophysiological device （EPD） placement, perioperative antiplatelet management is a current challenge. In this study, we investigated the incidence of pocket hema-toma formation after EPD placement in patients undergoing DAP therapy or an alternative low-molecular-weight heparin （LMWH） regimen. Methods This clinical observational study was performed from July 2010 to July 2012. In total, 171 patients were enrolled in the analysis after meeting the inclusion criteria. These patients were divided into two groups： 86 patients were treated with DAP therapy at the time of device implantation, and the DAP therapy was discontinued for 5 to 7 days and replaced with enoxaparin before device implantation in the other 85 patients. Adenosine phosphate （ADP）-mediated platelet aggregation and arachidonic acid-induced platelet aggregation were tested preoperatively. We compared the incidence of pocket hematoma between the two groups and the association of pocket hematoma develop-ment with ADP-mediated platelet aggregation and arachidonic acid-induced platelet aggregation.Results The incidence of pocket hema-toma in the patients who continued DAP was lower than that in the patients who replaced the dual antiplatelet regimen with LMWH （3.49%vs. 16.47%, respectively;X2 = 6.66,P 〈 0.01）. Among the patients who continued DAP therapies, the rate of ADP-mediated platelet aggre-gation inhibition in patients with pocket hematomas was higher than that in patients without pocket hematomas. None of the patients under-going DAP or enoxaparin therapy developed pocket infection, thromboembolic events, or other serious complications. Multiple logistic re-gression analysis revealed that LMWH therapy was an independent risk factor for the development of pocket hematoma （RR = 0.054, 95%CI = 0.012-0.251）. Furthermore, patients undergoing LMWH therapy were 5.1-fold more likely to develop pocket hematomas than were DAP-treated individuals.Conclusion Continuance of DAP therapy does not increase the risk of pocket hematoma formation after EPD placement.

Biology of hyaluronan: Insights from genetic disorders of hyaluronan metabolism

Hyaluronan is a rapidly turned over component of the vertebrate extracellular matrix. Its levels are determined, in part, by the hyaluronan synthases, HAS1, HAS2, and HAS3, and three hyaluronidases, HYAL1, HYAL2 and HYAL3. Hyaluronan binding proteins also regulate hyaluronan levels although their involvement is less well understood. To date, two genetic disorders of hyaluronan metabolism have been reported in humans: HYAL1 deficiency(Mucopolysaccharidosis IX) in four individuals with joint pathology as the predominant phenotypic finding and HAS2 deficiency in a single person having cardiac pathology. However, inherited disorders and induced mutations affecting hyaluronan metabolism have been characterized in other species. Overproduction of hyaluronan by HAS2 results in skin folding and thickening in shar-pei dogs and the naked mole rat, whereas a complete deficiency of HAS2 causes embryonic lethality in mice due to cardiac defects. Deficiencies of murine HAS1 and HAS3 result in a predisposition to seizures. Like humans, mice with HYAL1 deficiency exhibit joint pathology. Mice lacking HYAL2 have variably penetrant developmental defects, including skeletal and cardiac anomalies. Thus, based on mutant animal models, a partial deficiency of HAS2 or HYAL2 might be compatible with survival in humans, while complete deficiencies of HAS1, HAS3, and HYAL3 may yet be recognized.

Structural and functional evidence for two separate oligosaccharide binding sites of Pasteurella multocida hyaluronan synthase

Pasteurella multocida hyaluronan synthase (PmHAS) is a bi-functional glycosyltransferase, containing a β1,3-glucuronyltransferase and β1,4-N-acetylglucosaminetransferase domain. PmHAS catalyzes the elongation of hyaluronan (HA) through the sequential addition of single monosaccharides to the non-reducing end of the hyaluronan chain. Research is focused on the relation between the length of the HA oligosaccharide and the single-step elongation kinetics from HA4 up to HA9. It was found that the turnover number kcat increased with length to maximum values of 11 and 14 s-1 for NAc- and UA-transfer, respectively. Interestingly, the specificity constant kcat/KM increased with polymer length from HA5 to HA7 to a value of 44 mM-1s-1, indicating an oligosaccharide binding site with increasing specificity towards a heptasaccharide at the UA domain. The value of kcat/KM remained moderately constant around 8 mM-1s-1 for HA4, HA6, and HA8, indicating a binding site with significantly lower binding specificity at the NAc domain than at the UA domain. These findings are further corroborated by a structural homology model of PmHAS, revealing two distinct sites for binding of oligosaccharides of different sizes, one in each transferase domain. Structural alignment studies between PmHAS and glycosyltransferases of the GT-A fold showed significant similarity in the binding of the UDP-sugars and the orientation of the acceptor substrate. These similarities in substrate orientation in the active site and in essential amino acid residues involved in substrate binding were utilized to localize the two HA oligosaccharide binding sites.

Combined effect of Traditional Chinese Medicine decoction and low-molecular-weight heparin calcium on the postoperative deep venous thrombosis in patients with lower limb fracture

OBJECTIVE: To investigate the combined effect of Traditional Chinese Medicine(TCM) decoction and low-molecular-weight heparin calcium on deep vein thrombosis(DVT) induced by surgery in patients with lower limb fracture.METHODS: Totally 86 hospitalized patients with DVT after surgery of lower limb fracture between September 2012 and January 2015 were recruited and randomly divided into control group and observation group, 43 cases in each group. The patients in the control group were treated with subcutaneous injection of low-molecular-weight heparin calcium, and those in the observation group were additionally given Danshen Injection and TCM decoction. The differences between two groups in occurrence rate, medication time, therapeutic effects,recurrence rate of thrombosis, activated partial thromboplastin time(APTT), and prothrombin time(PT) were compared.RESULTS: The occurrence rate of DVT in observation group(4.65%, 2/43) was lower than that in control group(27.91%,12/43)(P<0.05). The medication time of observation group was(6.15±2.94) d, shorter than(9.76±3.12) d in the control group(P<0.05). In observation group, 2 cases of DVT were cured(2/2); in the control group, 9 cases presented therapeutic effects and the total effective rate was 75.00%(9/12). The improvement of APTT and PT in the observation group was better than that in the control group(P<0.05).CONCLUSION: Integrative TCM decoction plus low-molecularweight heparin calcium is superior to applicaton of low-molecularweight heparin calcium alone in reducing and treating DVT in the postoperative patients with lower limb fracture.

Effects of hyaluronan oligosaccharides on apoptosis ofhuman gingival fibroblasts

An?increased?content?of?low?molecular?weight (LMW)- HA?was?found?in?human?gingiva?during?the?initial phase of?periodontitis. A?number?of?functions?have?been?described?for LMW-HA?in?inflammatory?processes.?It?is?also?demonstrated?that?LMWHA?induces?apoptosis?in?chondrocytes?and?tumor?cells,?however, effects of?LMWHA on the apoptosis?of?gingival?fibroblasts?(GFs) remain?unclear. The?purpose?of?this?study?was?to?investigate?the effects?of HA?oligosaccharides?(HAoligo) on?the apoptosis of GFs. GFs were?isolated?from?palatal?gingival?tissues around?the upper?first?premolars of eight youth?(6 -10?years?old)?and eight adult?(26 -35?years?old) subjects.?Cultured?GFs?were?subjected?to?the?analyses,?ELISA?for?cell?proliferation,?quantitative real?time-PCR?for?gene?expression?of?Bcl-2,?and?caspase-3?assay?for?apoptotic potency. Proliferative?activity?of?cultured?GFs was increased?

Biological Evaluation of Tissue-Engineered Cartilage Using Thermoresponsive Poly(<i>N</i>-isopropylacrylamide)-Grafted Hyaluronan

In order to contribute to the development of minimally invasive surgery techniques for autologous chondrocyte implantation, a novel self-assembling biomaterial consisting of thermoresponsive poly(N-isopropylacrylamide)-grafted hyaluronan (PNIPAAm-g-HA) has been synthesized as an injectable scaffold for cartilage tissue engineering. The aim of this study was to investigate the efficacy and cytocompatibility of PNIPAAm-g-HA to normal chondrocytes by using reverse transcription-polymerase chain reaction (RT-PCR) analysis and histochemical staining in preliminary in vitro and in vitro experiments. Hematoxylin and eosin staining showed homogeneous distribution of cells in the PNIPAAm-g-HA hydrogel in 3-dimensional in vitro cultivation. Alcian blue staining also indicated that abundant extracellular matrix formation, including acidic glycosaminoglycans, occurred in tissue-engineered cartilage over time in vitro. Cartilage-related gene expression patterns, which were tested in rabbit normal chondrocytes embedded in the hydrogel, were almost maintained for 4 weeks. Transforming growth factor-β1 (TGF-β1) stimulation enhanced the expression of SRY-related HMG box-containing gene 9 (Sox9) and type X collagen genes suggesting promotion of chondrogenic differentiation. Histochemical evaluation showed neocartilage formation following subcutaneous implantation of the chondrocyte-gel mixture in nude mice. Furthermore, TGF-β1 stimulation promoted production and maturation of the extracellular matrix of the in situ tissue engineered hyaline cartilage. These data suggested that PNIPAAm-g-HA could be a promising biomaterial, i.e., a self-assembling and injectable scaffold for cartilage tissue engineering.

Bacteriostatic Effects of Hyaluronan-Based Bioresorbable Membrane

Purpose: The purpose of this study is to determine the presence of bacteriostatic effects of hyaluronan-based bioresorbable membrane (HA/CMC) on selected major bacterial strains in digestive organs. Methods: We firstly evaluated the growth inhibition effect of HA/CMC for E. coli and S. aureus by determining the optical density (OD)650 in the incubation medium. At second, to determine the viable counts of bacteria, total adenosine triphosphate (ATP) were measured with five groups;several concentrations of HA/CMC and control. Results: OD curve gradually elevated and reached to plateau at 4 hours in E. coli. and 6 hours in S. aureus. After reaching plateau, the growth inhibition of both strains was statistically significantly correlated to the concentrations of HA/CMC. The ATP productions had statistically significant differences at 6 hours after incubation and inhibited in dose-dependence of a well-dissolved HA/CMC. Conclusion: HA/CMC may have dose-dependently bacteriostatic effects on S. aureus and E. coli.

Injectable <i>in situ</i>crosslinkable hyaluronan-polyvinyl phosphonic acid hydrogels for bone engineering

A novel injectable hydrogel that was synthesized by in situ crosslinking of hyaluronan and polyvinyl phosphonic acid was proposed in this study. Fourier transform infrared spectrum (FT-IR) analysis, scanning electron microscope (SEM), pH measurement, and biodegradation test were used to confirm its characteristics. The results permitted to prove successful crosslinking, observe the inner morphology of hydrogel and pore sizes distribution, and determine the decomposition of hydrogel components during incubation time. Result of pH measurement showed that the pH scale of hydrogel decreased when volume of PVPA increased. As a consequence, it affected the cytotoxicity value, cell proliferation, and cell growth behaviors of each hydrogel. Optical microscope observation showed that chondroblasts cell proliferated well on HA-PVPA hydrogel. Therefore, these results suggest that the new injectable hydrogel is appropriate for bone/cartilage regeneration applications.