The aging behavior of degradable plastic polylactic acid under the interaction of environmental factors.

Microplastics leaching from aging biodegradable plastics pose potential environmental threats. This study used response surface methodology (RSM) to investigate the impact of temperature, light, and humidity on the aging characteristics of polylactic acid (PLA). Key evaluation metrics included the C/O ratio, functional groups, crystallinity, surface topography, and mechanical properties. Humidity was discovered to have the greatest effect on the ageing of PLA, followed by light and temperature. The interactions between temperature and light, as well as humidity and sunlight, significantly impact the aging of PLA. XPS analysis revealed PLA underwent aging due to the cleavage of the ester bond (O-C=O), resulting in the addition of C=O and C-O. The aging process of PLA was characterized by alterations in surface morphology and augmentation in crystallinity, resulting in a decline in both tensile strength and elongation. These findings might offer insights into the aging behavior of degradable plastics under diverse environmental conditions.

Optimisation and Effect Analysis of the Blood Collection Method in Pre-Deposit Autotransfusion Patients Undergoing Thoracotomy Surgery.

Background and Purpose: To explore the feasibility of the modified blood collection method in pre-deposit autotransfusion in patients undergoing thoracotomy surgery. Methods: This double-blinded randomised controlled trial enrolled 92 patients from the cardiothoracic surgery department from February 2019 to October 2020. Results: Compared with the conventional blood collection method, the modified blood collection method avoided blood overflow from the oblique plane of the needle (χ2 = 61.986, P < 0.01) and reduced the diameter of the bruising area after 24 hours (χ2 = 24.611, P < 0.01). Furthermore, due to optimising the blood collection method, diastolic blood pressure reduced slightly before and after blood collection (t = 2.036, P < 0.05), and patients in the test group had less pain (based on the numerical rating score) (t = 5.556, P < 0.01). Meanwhile, the time required to collect 400 mL of blood was shortened (t = 17.744, p < 0.01). Conclusion: An improved blood collection method can enhance the blood donation experience, avoid blood spillage, lessen pain and reduce adverse reactions. This may be of great significance in ensuring blood quality and the safety of subsequent transfusions. Clinical Trials Registration: ClinicalTrials.gov Identifier: NCT05539846.

Describing immune factors associated with Hepatitis B surface antigen loss: A nested case-control study of a Chinese sample from Wuwei City.

Background: Hepatitis B surface antigen (HBsAg) loss is considered a functional cure for chronic hepatitis B (CHB), however, several factors influence HBsAg loss. Methods: 29 CHB patients who had achieved HBsAg loss, were selected and 58 CHB patients with persistent HBsAg were matched, according to gender and age (+/- 3 years). Logistic regression and restricted cubic spline (RCS) modelling were performed. Results: Multivariate-adjusted logistic regression, based on stepwise selection, showed that baseline HBsAg levels negatively correlated with HBsAg loss (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.98-0.99). Interferon treatment positively related with HBsAg loss (OR = 7.99, 95%CI = 1.62-44.88). After adjusting for age, HBsAg level, ALT level, HBeAg status and interferon treatment, MMP-1 (OR = 0.66, 95%CI = 0.44-0.97), CXCL9 (OR = 0.96, 95%CI = 0.93-0.99) and TNF-R1 (OR = 0.97, 95%CI = 0.94-0.99) baseline levels all negatively correlated with HBsAg loss. Our multivariate-adjusted RCS model showed that baseline CXCL10 was associated with HBsAg loss although the relationship was "U-shaped". Conclusions: Cytokines such as MMP-1, CXCL9, CXCL10 and TNF-R1 are important factors which influence HBsAg loss. It may be possible to develop a nomogram which intercalates these factors; however, further research should consider immune processes involved in HBsAg loss.

The efficacy and safety of intrapleural hyperthermic perfusion in patients with malignant pleural effusion undergoing video-assisted thoracic surgery: a single-arm clinical trial.

Background: Patients with malignant pleural effusion (MPE) are usually treated with an indwelling pleural catheter (IPC) or pleurodesis. However, most do not achieve a satisfactory control rate of pleural effusion and have poor prognosis. Distilled water has cytocidal effects of hypotonic shock and can result in the lysis of cancer cells which was used in surgery to eradicate cancer cells. However, there is no study focusing on the efficacy of intrapleural hyperthemic perfusion for MPE under video-assisted thoracoscopic surgery (VATS). This study explored the efficacy and safety of intrapleural hyperthermic perfusion (IHP) with distilled water in patients with MPE. Methods: In this retrospective, single-arm trial, patients admitted to department of cardiothoracic surgery of Taizhou hospital and diagnosed with MPE caused by non-small cell lung cancer from January 2014 and December 2018 were included. The clinical characteristics including age, gender smoking history, Karnofsky score, volume of pleural effusion, TNM cancer stage, pathology, genetic test of patients were collected. Patients were treated with hyperthermic perfusion. The pleural cavity was perfused with 43.0 ℃ distilled water for 60 minutes under video-assisted thoracic surgery (VATS). The efficacy of treatment was defined as follows: (I) complete remission (CR; no recurrence of pleural effusion after IHP for at least four weeks); (II) partial remission (PR; pleural effusion was decreased by 50% and the condition lasted for 4 weeks; or (III) no remission (NR; no decrease in pleural effusion). Kaplan-Meier method with a log-rank test was used for survival analysis. Cox proportional hazards regression models were applied to perform univariate and multivariate analyses. Results: From January 2014 through December 2018, 30 patients with MPE caused by non-small cell lung cancer (NSCLC) were treated with hyperthermic perfusion. There were no serious reportable clinical complications associated with the procedure. The response rate was 96.7%, with 63.3% experiencing PR and 33.3% achieving CR. The overall survival (OS) ranged from 2 to 46 months. The median survival was 12 months. Conclusions: IHP proved to be a feasible and safe strategy for patients with MPE in our study but it still needs to be verified with a larger, prospective and randomized trial in the future.

A modified urinary catheterisation technique to reduce urine leakage: A prospective randomised study.

BACKGROUND: Long-term indwelling catheters assist people who are unable to use another bladder management method. However, urine leakage is a common problem with an indwelling urinary catheter. This study aims to determine whether a modified catheterisation technique would reduce urine leakage incidence. METHODS: Participants were randomly divided into conventional or modified catheterisation groups. In the modified technique group, the volume of fluid that needed to be injected into the balloon to obtain a suitable catheter front-end curvature (120-145°) was measured before catheterisation. Baseline characteristics and first-time success rates and procedure durations were similar between groups. RESULTS: There were 30 patients in each group. Compared with conventional catheterisation, the modified catheterisation group had smaller residual urine volume (median 11 mL Vs. 30.5 mL, p<0.001) and more leakage-free days (30 days Vs. 10 days, p<0.001). Leakage-free survival was longer in the modified catheterisation group (p<0.001). The residual urine volume (>17 vs ≤17 ml (median); incident rate ratio (IRR), 28.710; 95%CI, 4.114-200.331; p=0.001) was independently associated with urine leakage. CONCLUSIONS: The modified catheterisation technique may reduce the incidence of urine leakage.

Analgesic Pump Tubing Securement to Prevent Dislodgement of Peripheral Vein Indwelling Catheter.

PURPOSE: This study aims to compare the incidence of complications when using a new approach to secure an indwelling peripheral venous catheter (PVC), involving tying of the tube with a surgical knot at two places and several layers of elastic adhesive bandage, with a standard approach using sterile, transparent, and protective film. METHODS: This study enrolled 311 consecutive adults undergoing thoracoscopic lobectomy under general anesthesia at Taizhou Hospital of Zhejiang Province between October 2017 and May 2018. Patients were randomized to experimental and control groups and were followed for up to 72 hours. The primary endpoint was dislodgement of the PVC. Secondary endpoints were blood in the catheter; analgesia pump obstruction alarm; time taken and cost of PVC replacement; replacement of securing materials and analgesia pump line; and time and cost of replacing them. All adverse events were recorded. FINDINGS: Final analysis included 248 patients (experimental group: n = 126; control group: n = 122). PVC dislodgement was less frequent in the experimental group than in the control group. In the control group, 78.7% of patients required replacement of securing materials (costing 37 cents each time) and 13.1% required PVC replacement (costing 3.6 dollars each time), necessitating additional nursing time. No patients in the experimental group required replacement of the PVC or securing materials. Blisters were less common in the experimental group than in the control group (0% vs 9.84%, P < .001). No patients had limb edema. CONCLUSIONS: This new method of securing an analgesia pump line can reduce traction on the indwelling PVC, lowering the dislodgement rate.

Impacts of Starch and the Interactions Between Starch and Other Macromolecules on Wheat Falling Number.

Wheat with a low falling number (FN) has been particularly prevalent in recent years and has resulted in a loss of more than $140 million in a single year in the wheat industry in the Pacific Northwest of the United States. FN measurement is a standard method for the evaluation of grain α-amylase activity, and a low FN indicates a reduction in hot wholemeal paste viscosity due to sprouting damage. Recent studies show that a low FN may result from a developmental change of starch and adverse effects of non-α-amylase macromolecules on wheat. In this review, we describe the principles of FN measurement and the relationship between FN and α-amylase. We also discuss the isozymes, locations, and inhibitors of wheat α-amylase. The effects of various aspects of starch, which is the substrate of α-amylase, on wheat FN are also discussed, including starch structural characteristics (for example, starch granule architecture), starch susceptibility to α-amylase, and the interaction between starch and nonstarch macromolecules (for example, lipids). Studies on the effects of planting environments (for example, temperature) and agronomic practices (for example, irrigation and fertilization) on both starch paste viscosity and FN are also reviewed. This paper highlights the importance of considering the impacts of starch and the interactions of starch and other macromolecules, including wheat α-amylase, on wheat FN, which is important for developing strategies to solve the low FN problem.

Polyamidoamine dendrimers can improve the pulmonary absorption of insulin and calcitonin in rats.

The absorption-enhancing effects of polyamidoamine (PAMAM) dendrimers with various generations (G0-G3) and concentrations [0.1%-1.0% (w/v)] on the pulmonary absorption of peptide and protein drugs were studied in rats. Insulin and calcitonin were chosen as models of peptide and protein drugs, and their pulmonary absorption with or without PAMAM dendrimers was examined by in vivo pulmonary absorption studies. PAMAM dendrimers significantly increased the pulmonary absorption of insulin and calcitonin in rats, and their absorption-enhancing effects were generation dependent. The rank order of absorption enhancement effect of these PAMAM dendrimers was G3 > G2 > G1 > G0. For the same generation, the absorption-enhancing effects of PAMAM dendrimers were shown to be concentration dependent. The toxicity of these PAMAM dendrimers in the lung tissues was evaluated by measuring the release of protein and the activities of lactate dehydrogenase (LDH) in bronchoalveolar lavage fluid (BALF). The PAMAM dendrimers with various generations and concentrations did not significantly increase the release of protein and the activities of LDH in BALF, indicating that these dendrimers did not cause any membrane damage to the lung tissues. The zeta potentials of insulin and calcitonin solutions changed to positive by the addition of PAMAM dendrimers, and the degree of positive charge as determined by the zeta potentials was linearly correlated with the absorption-enhancing effects of the PAMAM dendrimers. This positive charge of the PAMAM dendrimers might be related to their absorption-enhancing mechanisms for improving the pulmonary absorption of insulin and calcitonin in rats. In conclusion, the PAMAM dendrimers are suitable absorption enhancers to improve the pulmonary absorption of insulin and calcitonin without any membrane damage to the respiratory tissues.

Intraflagellar transport protein 122 antagonizes Sonic Hedgehog signaling and controls ciliary localization of pathway components.

Primary cilia are required for proper Sonic Hedgehog (Shh) signaling in mammals. However, their role in the signal transduction process remains unclear. We have identified sister of open brain (sopb), a null allele of mouse Intraflagellar transport protein 122 (Ift122). IFT122 negatively regulates the Shh pathway in the cilium at a step downstream of the Shh ligand and the transmembrane protein Smoothened, but upstream of the Gli2 transcription factor. Ift122(sopb) mutants generate primary cilia, but they show features of defective retrograde intraflagellar transport. IFT122 controls the ciliary localization of Shh pathway regulators in different ways. Disruption of IFT122 leads to accumulation of Gli2 and Gli3 at cilia tips while blocking the ciliary localization of the antagonist TULP3. Suppressor of Fused and Smoothened localize to the cilium through an IFT122-independent mechanism. We propose that the balance between positive and negative regulators of the Shh pathway at the cilium tip controls the output of the pathway and that Shh signaling regulates this balance through intraflagellar transport.

Polyamidoamine dendrimers as novel potential absorption enhancers for improving the small intestinal absorption of poorly absorbable drugs in rats.

Effects of polyamidoamine (PAMAM) dendrimers on the intestinal absorption of poorly absorbable drugs were examined by an in situ closed loop method in rats. 5(6)-Carboxyfluorescein (CF), fluorescein isothiocyanate-dextrans (FDs) with various molecular weights, calcitonin and insulin were used as model drugs of poorly absorbable drugs. The absorption of CF, FD4 and calcitonin from the rat small intestine was significantly enhanced in the presence of PAMAM dendrimers. The absorption-enhancing effects of PAMAM dendrimers for improving the small intestinal absorption of CF were concentration and generation dependent and a maximal absorption-enhancing effect was observed in the presence of 0.5% (w/v) G2 PAMAM dendrimer. However, G2 PAMAM dendrimer had almost no absorption-enhancing effect on the small intestinal absorption of macromolecular drugs including FD10 and insulin. Overall, the absorption-enhancing effects of G2 PAMAM dendrimer in the small intestine decreased as the molecular weights of drug increased. However, G2 PAMAM dendrimer did not enhance the intestinal absorption of these drugs with different molecular weights in the large intestine. Furthermore, we evaluated the intestinal membrane damage with or without G2 PAMAM dendrimer. G2 PAMAM dendrimer (0.5% (w/v)) significantly increased the activities of lactate dehydrogenase (LDH) and the amounts of protein released from the intestinal membranes, but the activities and amounts of these toxic markers were less than those in the presence of 3% Triton X-100 used as a positive control. Moreover, G2 PAMAM dendrimer at concentrations of 0.05% (w/v) and 0.1% (w/v) did not increase the activities and amounts of these toxic markers. These findings suggested that PAMAM dendrimers at lower concentrations might be potential and safe absorption enhancers for improving absorption of poorly absorbable drugs from the small intestine.

The effect of wellsolve, a novel solubilizing agent, on the intestinal barrier function and intestinal absorption of griseofulvin in rats.

The effect of Wellsolve, a new solubilizing agent, on the function of intestinal membrane barrier and transporters including P-glycoprotein (P-gp) and peptide transporter (PEPT1) was examined by an in vitro diffusion chamber and an in situ closed loop method. The model drugs used in this study were 5(6)-carboxyfluorescein (CF), rhodamine123 (a P-glycoprotein substrate), cephalexin (a typical substrate for PEPT1) and griseofulvin (a BCS Class II drug). Intestinal absorption of CF was not affected by the addition of 1-10% (v/v) Wellsolve, while 20% (v/v) Wellsolve significantly enhanced its intestinal absorption by the in situ absorption study. Therefore, this finding suggested that high concentration of Wellsolve might alter the intestinal barrier function. The mucosal to serosal (absorptive) and serosal to mucosal (secretory) transport of rhodamine123 was significantly inhibited in the presence of 5.0-20% (v/v) of Wellsolve, suggesting that Wellsolve might not affect the function of P-gp in the intestine. The intestinal transport of cephalexin was not affected in the presence of Wellsolve, suggesting that this solubilizing agent might not change the function of PEPT1 in the intestine. In the toxicity studies, we found that 1-10% (v/v) Wellsolve did not change the release of lactate hydrogenase (LDH) and protein from the intestinal membranes. Furthermore, intestinal absorption of griseofulvin in the presence of 10% (v/v) Wellsolve significantly increased as compared with the control. In summary, Wellsolve at lower concentrations might be a potent and safe solubilizing agent for improving the solubility and absorption of poorly water-soluble drugs including griseofulvin.

Modulating effect of polyethylene glycol on the intestinal transport and absorption of prednisolone, methylprednisolone and quinidine in rats by in-vitro and in-situ absorption studies.

The effects of polyethylene glycol 20000 (PEG 20000) on the intestinal absorption of prednisolone, methylprednisolone and quinidine, three P-glycoprotein (P-gp) substrates, across the isolated rat intestinal membranes were examined by an in-vitro diffusion chamber system. The serosal-to-mucosal (secretory) transport of these P-gp substrates was greater than their mucosal-to-serosal (absorptive) transport, indicating that their net movement across the intestinal membranes was preferentially in the secretory direction. The polarized secretory transport of these drugs was remarkably diminished and their efflux ratios decreased in the presence of PEG 20000. In addition, PEG 20000 did not affect the transport of Lucifer yellow, a non-P-gp substrate. The intestinal membrane toxicity of PEG 20000 was evaluated by measuring the release of alkaline phosphatase (ALP) and protein from the intestinal membranes. The release of ALP and protein was enhanced in the presence of 20 mM sodium deoxycholate (NaDC), a positive control, while these biological parameters did not change in the presence of 0.1-5% (w/v) PEG 20000. These findings indicated that the intestinal membrane damage caused by PEG 20000 was not a main reason for the enhanced absorptive transport of these P-gp substrates in the presence of PEG 20000. Furthermore, the transepithelial electrical resistance (TEER) of rat jejunal membranes in the presence or absence of PEG 20000 was measured by a diffusion chamber method. PEG 20000 (0.1-5.0 % w/v) did not change the TEER values of the rat jejunal membranes, indicating that the increase in the absorptive transport of these P-gp substrates might not be due to the increased transport of these P-gp substrates via a paracellular pathway caused by PEG 20000. Finally, the effect of PEG 20000 on the intestinal absorption of quinidine was examined by an in-situ closed-loop method. The intestinal absorption of quinidine was significantly enhanced in the presence of 0.1-1.0% (w/v) PEG 20000. These findings suggest that PEG 20000 might be a useful excipient to improve the intestinal absorption of quinidine, which is mainly secreted by a P-gp-mediated efflux system in the intestine.

Improvement of pulmonary absorption of insulin and other water-soluble compounds by polyamines in rats.

The absorption enhancing effects of polyamines, spermine (SPM), spermidine (SPD) and putrescine (PUT) on the pulmonary absorption of poorly absorbable drugs were studied in rats. Insulin, 5(6)-carboxyfluorescein (CF), and fluorescein isothiocyanate-labeled dextrans (FDs) were chosen as models of poorly absorbable drugs. The absorption of insulin from the lung was enhanced in the presence of SPM and SPD, while PUT had almost no absorption enhancing effect for improving the pulmonary absorption of insulin in rats. SPM also improved the pulmonary absorption of FDs with various molecular weights, although we found almost no significant difference in the pulmonary absorption of CF with or without SPM. As for the pulmonary membrane toxicity of SPM, there was no significant difference in the release of protein and lactate dehydrogenase (LDH) with or without SPM in bronchoalveolar lavage fluid (BALF), indicating that SPM did not cause any membrane damage to the lung tissues. Furthermore, SPM did not affect the stability of insulin in BALF, suggesting that SPM might increase the permeability of insulin across the alveolar epithelium. In conclusion, polyamines, especially SPM can effectively improve the pulmonary absorption of insulin and other macromolecules without any membrane damage to the lung tissues.

Effects of Labrasol and other pharmaceutical excipients on the intestinal transport and absorption of rhodamine123, a P-glycoprotein substrate, in rats.

Effects of Labrasol and other pharmaceutical excipients on the intestinal transport and absorption of rhodamine123, a P-glycoprotein substrate (P-gp) were examined. Intestinal transport and absorption studies were examined by an in vitro diffusion chamber method and an in situ closed loop method. We evaluated the intestinal membrane damage produced by Labrasol by measuring the release of protein and alkaline phosphatase (ALP). Labrasol (0.075-0.1% (v/v)) increased the absorptive transport of rhodamine123 and decreased its secretory transport in the in vitro transport studies. However, Labrasol did not change the transport of Lucifer yellow, a non-P-gp substrate, suggesting that the effect of Labrasol on the transport of drugs was specific for rhodamine123. We observed almost no intestinal membrane damage in the presence of Labrasol. These findings suggest that the increase in the absorptive transport of rhodamine123 in the presence of Labrasol may not be due to its intestinal membrane damage. In the in situ absorption studies, we found that Labrasol (0.1% (v/v)) significantly enhanced the intestinal absorption of rhodamine123 in rats, although the absorption enhancing effect of Labrasol was much less than that of verapamil. These findings suggest that low concentrations of Labrasol might inhibit the function of P-gp in the intestine, thereby increasing intestinal absorption and bioavailability of P-gp substrates including rhodamine123. However, we may also consider the contribution to the enhanced intestinal absorption of rhodamine123 via a passive transport in addition to the inhibitory action of Labrasol for the function of P-gp in the intestine.

Modulation of intestinal P-glycoprotein function by polyethylene glycols and their derivatives by in vitro transport and in situ absorption studies.

We examined the effect of polyethylene glycols (PEGs) with different molecular weights and their derivatives on the intestinal absorption of rhodamine123, a P-glycoprotein (P-gp) substrate, across the isolated rat intestinal membranes by an in vitro diffusion chamber system. The serosal to mucosal (secretory) transport of rhodamine123 was greater than its mucosal to serosal (absorptive) transport, indicating that the net movement of rhodamine123 across the intestinal membranes was preferentially secretory direction. The secretory transport of rhodamine123 was inhibited by the addition of PEGs with average molecular weights of 400, 2000 and 20,000, irrespective of its molecular weight. The inhibitory effects of these PEGs for the intestinal P-gp function were concentration dependent over the range 0.1-20% (v/v or w/v). Similar inhibitory effect for the intestinal P-gp function was observed when PEG derivatives including PEG monolaurate, PEG monooleate and PEG monostearate were added to the mucosal site of the chambers. Furthermore, we also examined effect of PEG20,000 on the intestinal absorption of rhodamine123 by an in situ closed loop method. The intestinal absorption of rhodamine123 was enhanced in the presence of PEG20,000. These findings suggest that PEGs and their derivatives are useful excipients to inhibit the function of intestinal P-gp, thereby improving the intestinal absorption of P-gp substrates, which are secreted by a P-gp-mediated efflux system.