Ileocolonic-Targeted JAK Inhibitor: A Safer and More Effective Treatment for Inflammatory Bowel Disease

Janus kinase (JAK) inhibitors, such as tofacitinib (Xeljanz) and filgotinib (Jyseleca), have been approved for treatment of ulcerative colitis with several other JAK inhibitors in late-stage clinical trials for inflammatory bowel disease (IBD). Despite their impressive efficacy, the risk of adverse effects accompanying the use of JAK inhibitors has brought the entire class under scrutiny, leading to them receiving an FDA black box warning. In this study we investigated whether ileocolonic-targeted delivery of a pan-JAK inhibitor, tofacitinib, can lead to increased tissue exposure and reduced systemic exposure compared to untargeted formulations. The stability of tofacitinib in the presence of rat colonic microbiota was first confirmed. Next, in vivo computed tomography imaging was performed in rats to determine the transit time and disintegration site of ileocolonic-targeted capsules compared to gastric release capsules. Pharmacokinetic studies demonstrated that systemic drug exposure was significantly decreased, and colonic tissue exposure increased at 10 mg/kg tofacitinib dosed in ileocolonic-targeted capsules compared to gastric release capsules and an oral solution. Finally, in a rat model of LPS-induced colonic inflammation, targeted tofacitinib capsules significantly reduced concentrations of proinflammatory interleukin 6 in colonic tissue compared to a vehicle-treated control (p = 0.0408), unlike gastric release tofacitinib capsules and orally administered dexamethasone. Overall, these results support further development of ileocolonic-targeted tofacitinib, and potentially other specific JAK inhibitors in pre-clinical and clinical development, for the treatment of IBD.

Topical formulation based on disease-specific nanoparticles for single-dose cure of psoriasis

First-line treatments for mild to moderate psoriasis are typically topical formulations containing corticosteroids, however, the therapeutic efficacy of these formulations is compromised by limited penetration and skin retention. Even more challenging, off-target corticosteroids are known to adversely affect healthy skin, including induction of epidermal and dermal atrophy. Here, we report a nanoparticle-based topical formulation that cures psoriasis in a single dose, but leaves healthy skin intact. Specifically, we developed tris(hydroxymethyl)aminomethane-modified bioadhesive nanoparticles (Tris-BNPs) that exploit the high permeability characteristic of psoriasis to penetrate only psoriatic skin but not the healthy skin. Furthermore, as Tris-BNPs diffuse and penetrate into the epidermis, the Tris molecules slowly diffuse away, exposing the aldehyde groups of BNPs, which can bind to amine groups present within lesional skin, leading to long local retention of BNPs in lesions of psoriatic skin. The accumulated BNPs within lesions release corticosteroids over a ~ 3 day period to maintain local drug concentration above the therapeutic level. In addition to deeper penetration and longer retention compared with commercial psoriasis treatments, the topical applied Tris-BNPs were not affected by sweating, humidity, or active wiping due to their preferential accumulation between the stratum corneum and the basal cells of the epidermis. Overall, Tris-BNP as a topical formulation hold promise to overcome the limitations of current psoriasis treatment.

[Association of skin lesion severity with clinical features of psoriatic arthritis]

Objective: To investigate the relationship between psoriasis severity and clinical features in psoriatic arthritis (PsA). Methods: Patients were recruited from the Chinese REgistry of Psoriatic ARthritis (CREPAR) between December 2018 and June 2021, and data were collected including the baseline demographic characteristics, various clinical manifestations (including arthritis, nail disease, comorbidities), laboratory tests[including erythrocyte sedimentation rate(ESR), C-reactive protein (CRP)], health assessment questionnaire (HAQ). Body surface area (BSA) and psoriasis area and severity index (PASI) were selected for the tools of assessment of cutaneous psoriasis. Patients were divided to two groups, including the severe psoriasis group (BSA>10%) and the non-severe psoriasis group (BSA≤10%). Disease assessment included ankylosing spondylitis disease activity score (ASDAS), disease activity score 28 (DAS28) and disease activity in psoriatic arthritis (DAPSA). Results: 1 074 eligible patients with PsA were recruited, and 106 (9.9%) had severe psoriasis. Compared with non-severe psoriasis group, the severe psoriasis group had more peripheral joint involvement (including patients with ever or current peripheral arthritis, 94.3% vs. 85.6%), more polyarticular joint involvement (including patients with current peripheral arthritis, 74.0% vs. 58.2%), more axial joint involvement (51.4% vs. 39.9%), more nail disease (72.6% vs. 61.4%), more frequency of smoking (20.2% vs. 18.7%), and higher proportion of hypertension (23.4% vs. 14.4%). In addition, the severe psoriasis group had higher level of ESR [33(10, 70) mm/1h vs. 20(9, 38) mm/1h] and CRP [18.6(5.0, 60.8) mg/L vs. 7.0(2.4, 18.1) mg/L], higher values of DAS28-ESR (4.5±1.7 vs. 3.7±1.5), DAS28-CRP (4.2±1.5 vs. 3.4±1.4), ASDAS-ESR (3.5±1.4 vs. 2.6±1.2), and ASDAS-CRP(3.4±1.6 vs. 2.5±1.2), higher scores of HAQ [0.6(0.1, 1.0) vs. 0.3(0.0, 0.8)]. Conclusion: Patients with PsA with severe psoriasis bore a heavier disease burden. Therefore, clinicians were supposed to pay more attention to them. In addition to skin lesions, they should also focus on examination of other clinical manifestations, such as joints and nails.

Poly(lactic acid)-hyperbranched polyglycerol nanoparticles enhance bioadhesive treatment of esophageal disease and reduce systemic drug exposure

The effective treatment of esophageal disease represents a significant unmet clinical need, as existing treatments often lead to unnecessary systemic drug exposure and suboptimal concentrations at the disease site. Here, surface-modified bioadhesive poly(lactic acid)-hyperbranched polyglycerol nanoparticles (BNPs), with an average 100-200 nm diameter, were developed for local and sustained esophageal drug delivery. BNPs showed significantly higher adhesion and permeation into ex vivo human and rat esophageal tissue than non-adhesive nanoparticles (NNPs) and had longer residence times within the rat esophagus in vivo. Incubation with human esophagus (Het-1A) cells confirmed BNPs' biocompatibility at clinically relevant concentrations. In a rat model of achalasia, nifedipine-loaded BNPs significantly enhanced esophageal drug exposure, increased therapeutic efficacy, and reduced systemic drug exposure compared to NNPs and free drug. The safety of BNPs was demonstrated by an absence of intestinal, hepatic, and splenic toxicity following administration. This study is the first to demonstrate the efficacy of BNPs for esophageal drug delivery and highlight their potential for improving the lives of patients suffering with esophageal conditions.

A Non-Nutritive Feeding Intervention Alters the Expression of Efflux Transporters in the Gastrointestinal Tract

Intestinal interactions with nutrients, xenobiotics and endogenous hormones can influence the expression of clinically relevant membrane transporters. These changes in the gastrointestinal (GI) physiology can in turn affect the absorption of numerous drug substrates. Several studies have examined the effect of food on intestinal transporters in male and female humans and animal models. However, to our knowledge no studies have investigated the influence of a non-nutritive fibre meal on intestinal efflux transporters and key sex and GI hormones. Here, we show that a fibre meal increased the acute expression of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug-resistance-associated protein-2 (MRP2) in small intestinal segments in both male and female Wistar rats. Enzyme-linked immunosorbent assays were used for the protein quantification of efflux transporters and hormonal plasma concentration. In male rats, the fibre meal caused the plasma concentration of the GI hormone cholecystokinin (CCK) to increase by 75% and the sex hormone testosterone to decrease by 50%, whereas, in contrast, the housing food meal caused a decrease in CCK by 32% and testosterone saw an increase of 31%. No significant changes in the hormonal concentrations, however, were seen in female rats. A deeper understanding of the modulation of efflux transporters by sex, food intake and time can improve our understanding of inter- and intra-variability in the pharmacokinetics of drug substrates.

Crosstalk of physiological pH and chemical pKa under the umbrella of physiologically based pharmacokinetic modeling of drug absorption, distribution, metabolism, excretion, and toxicity

Introduction: Physiological pH and chemical pKa are two sides of the same coin in defining the ionization of a drug in the human body. The Henderson-Hasselbalch equation and pH-partition hypothesis form the theoretical base to define the impact of pH-pKa crosstalk on drug ionization and thence its absorption, distribution, metabolism, excretion, and toxicity (ADMET).Areas covered: Human physiological pH is not constant, but a diverse, dynamic state regulated by various biological mechanisms, while the chemical pKa is generally a constant defining the acidic dissociation of the drug at various environmental pH. Works on pH-pKa crosstalk are scattered in the literature, despite its significant contributions to drug pharmacokinetics, pharmacodynamics, safety, and toxicity. In particular, its impacts on drug ADMET have not been effectively linked to the physiologically based pharmacokinetic (PBPK) modeling and simulation, a powerful tool increasingly used in model-informed drug development (MIDD).Expert opinion: Lacking a full consideration of the interactions of physiological pH and chemical pKa in a PBPK model limits scientists' capability in mechanistically describing the drug ADMET. This mini-review compiled literature knowledge on pH-pKa crosstalk and its impacts on drug ADMET, from the viewpoint of PBPK modeling, to pave the way to a systematic incorporation of pH-pKa crosstalk into PBPK modeling and simulation.

Quantification of P-Glycoprotein in the Gastrointestinal Tract of Humans and Rodents: Methodology, Gut Region, Sex, and Species Matter

Intestinal efflux transporters affect the gastrointestinal processing of many drugs but further data on their intestinal expression levels are required. Relative mRNA expression and relative and absolute protein expression data of transporters are commonly measured by real-time polymerase chain reaction (RT-PCR), Western blot and mass spectrometry-based targeted proteomics techniques. All of these methods, however, have their own strengths and limitations, and therefore, validation for optimized quantification methods is needed. As such, the identification of the most appropriate technique is necessary to effectively translate preclinical findings to first-in-human trials. In this study, the mRNA expression and protein levels of the efflux transporter P-glycoprotein (P-gp) in jejunal and ileal epithelia of 30 male and female human subjects, and the duodenal, jejunal, ileal and colonic tissues in 48 Wistar rats were quantified using RT-PCR, Western blot and liquid chromatography-tandem mass spectrometry (LC-MS/MS). A similar sex difference was observed in the expression of small intestinal P-gp in humans and Wistar rats where P-gp was higher in males than females with an increasing trend from the proximal to the distal parts in both species. A strong positive linear correlation was determined between the Western blot data and LC-MS/MS data in the small intestine of humans (R² = 0.85). Conflicting results, however, were shown in rat small intestinal and colonic P-gp expression between the techniques (R² = 0.29 and 0.05, respectively). In RT-PCR and Western blot, an internal reference protein is experimentally required; here, beta-actin was used which is innately variable along the intestinal tract. Quantification via LC-MS/MS can provide data on P-gp expression without the need for an internal reference protein and consequently, can give higher confidence on the expression levels of P-gp along the intestinal tract. Overall, these findings highlight similar trends between the species and suggest that the Wistar rat is an appropriate preclinical animal model to predict the oral drug absorption of P-gp substrates in the human small intestine.

LncRNA NEAT1 promotes cardiac hypertrophy through microRNA-19a-3p/SMYD2 axis

OBJECTIVE

The role of NEAT1 in cancers has been demonstrated. But the role of NEAT1 in cardiac hypertrophy still remains unknown. This study aimed to elucidate the specific function of long non-coding RNA (lncRNA) NEAT1 in cardiac hypertrophy and its underlying mechanism.

PATIENTS AND METHODS

In this study, the in vivo and in vitro cardiac hypertrophy models were constructed by transverse aortic coarctation (TAC) procedure in rats and phenylephrine (PE) induction in primary cardiomyocytes, respectively. The expression levels of NEAT1, microRNA-19a-3p, SMYD2, and cardiac hypertrophic markers were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cardiac hypertrophy was evaluated as calculating the surface area of hypertrophic cardiomyocyte by fluorescein isothiocyanate (FITC)-Phalloidin staining. Luciferase Reporter Gene Assay was conducted to detect the binding of NEAT1, SMYD2, and microRNA-19a-3p.

RESULTS

The results showed that NEAT1 and SMYD2 were highly expressed in myocardium of rats with cardiac hypertrophy and PE-induced primary cardiomyocytes, whereas microRNA-19a-3p was lowly expressed. Besides, NEAT1 overexpression markedly upregulated levels of the cardiac hypertrophic markers. Moreover, FITC-Phalloidin staining also revealed hypertrophic cardiomyocytes overexpressing NEAT1. On the contrary, microRNA-19a-3p overexpression reduced the cardiomyocyte surface area and downregulated the levels of the cardiac hypertrophic markers. As luciferase reporter gene assay demonstrated, NEAT1 and SMYD2 could bind to microRNA-19a-3p. Finally, the gain-of-function experiments were designed to verify whether NEAT1 exerted its functions in cardiac hypertrophy by modulating SMYD2 and microRNA-19a-3p. Furthermore, both microRNA-19a-3p overexpression or SMYD2 knockdown could inhibit and reduce the cardiomyocyte surface area, and downregulate the levels of the cardiac hypertrophic markers.

CONCLUSIONS

In summary, NEAT1 promotes the occurrence and progression of cardiac hypertrophy by upregulating SMYD2 by binding to microRNA-19a-3p.

MicroRNA-494-3p alleviates inflammatory response in sepsis by targeting TLR6

OBJECTIVE

To clarify whether microRNA-494-3p could exert an anti-inflammation effect by suppressing the expression of toll-like receptor 6 (TLR6), thus inhibiting the development of sepsis.

PATIENTS AND METHODS

Plasma levels of microRNA-494-3p and TLR6 in sepsis patients and healthy controls were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Diagnostic potential of microRNA-494-3p in sepsis was evaluated by receiver operating characteristic (ROC) curve. In vitro macrophage inflammation model was established by lipopolysaccharides (LPS) induction in RAW264.7 cells. Expression levels of microRNA-494-3p, TLR6 and tumor necrosis factor-α (TNF-α) in LPS-induced RAW264.7 cells were observed. After transfection of microRNA-494-3p mimics in LPS-induced RAW264.7 cells, mRNA and protein levels of TNF-α were determined by qRT-PCR and Western blot, respectively. Meanwhile, cytoplasmic and nuclear fractions of nuclear factor-kappa B (NF-κB) p65 were respectively extracted for evaluating nuclear translocation of NF-κB p65 by Western blot analysis. Dual-luciferase reporter gene assay was performed to verify the binding between microRNA-494-3p and TLR6. Finally, rescue experiments were carried out to elucidate whether microRNA-494-3p attenuated sepsis-induced inflammation through degrading TLR6.

RESULTS

Plasma level of microRNA-494-3p in sepsis patients was markedly lower than healthy controls, while plasma level of TLR6 was conversely higher in sepsis patients. With the prolongation of LPS induction in RAW264.7 cells, expression levels of TLR6 and TNF-α gradually increased, whereas microRNA-494-3p expression decreased. Transfection of microRNA-494-3p mimics in RAW264.7 cells reduced TNF-α level, and inhibited nuclear translocation of NF-κB p65. TLR6 was found to be a target gene of microRNA-494-3p, and its expression was markedly downregulated by microRNA-494-3p overexpression. Finally, we proved that the inhibitory effects of microRNA-494-3p on TNF-α level and nuclear translocation of NF-κB p65 were reversed by TLR6.

CONCLUSIONS

High expression of microRNA-494-3p attenuated sepsis-induced inflammatory response by degrading TLR6.

Influences of up-regulation of miR-126 on septic inflammation and prognosis through AKT/Rac1 signaling pathway

OBJECTIVE

To explore the influences of the up-regulation of micro ribonucleic acid (miR)-126 on septic inflammation and prognosis through the AKT/Rac1 signaling pathway.

MATERIALS AND METHODS

Human pulmonary microvascular endothelial cells (HMVECs) were cultured and transfected with miR-126 mimics. The HMVECs in the logarithmic growth phase in different groups were incubated with thrombin. The transmembrane resistivity of HMVECs was detected as the permeability via Electric Cell-substrate Impedance Sensing (ECIS) system. The endothelial cell space was observed via immunofluorescence. The mouse model of sepsis was then established and the serum was extracted to detect interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The survival curve was plotted based on the death time. The Statistical Product and Service Solutions (SPSS) 22.0 was used for statistical analysis, and p<0.05 suggested that the difference was statistically significant.

RESULTS

Thrombin could significantly increase the permeability of HMVECs, while the overexpression of miR-126 markedly inhibited the increased permeability. The overexpression of miR-126 also reduced the endothelial cell space induced by thrombin. In addition, the serum IL-6 and TNF-α levels of sepsis mice in miR-126 overexpression group were significantly decreased compared to those in the control group. Moreover, the death rate of mice exogenously expressing miR-126 was lower than that in the control group.

CONCLUSIONS

The up-regulation of miR-126 inhibited the septic inflammation and improved the prognosis of sepsis mice through the AKT/Rac1 signaling pathway.

Effect of Food and an Animal's Sex on P-Glycoprotein Expression and Luminal Fluids in the Gastrointestinal Tract of Wistar Rats

The rat is one of the most commonly used animal models in pre-clinical studies. Limited information between the sexes and the effect of food consumption on the gastrointestinal (GI) physiology, however, is acknowledged or understood. This study aimed to investigate the potential sex differences and effect of food intake on the intestinal luminal fluid and the efflux membrane transporter P-glycoprotein (P-gp) along the intestinal tract of male and female Wistar rats. To characterise the intestinal luminal fluids, pH, surface tension, buffer capacity and osmolality were measured. Absolute P-gp expression along the intestinal tract was quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS). In general, the characteristics of the luminal fluids were similar in male and female rats along the GI tract. In fasted male rats, the absolute P-gp expression gradually increased from the duodenum to ileum but decreased in the colon. A significant sex difference (p < 0.05) was identified in the jejunum where P-gp expression in males was 83% higher than in females. Similarly, ileal P-gp expression in male rats was approximately 58% higher than that of their female counterparts. Conversely, following food intake, a significant sex difference (p < 0.05) in P-gp expression was found but in a contrasting trend. Fed female rats expressed much higher P-gp levels than male rats with an increase of 77% and 34% in the jejunum and ileum, respectively. A deeper understanding of the effects of sex and food intake on the absorption of P-gp substrates can lead to an improved translation from pre-clinical animal studies into human pharmacokinetic studies.

An animal's sex influences the effects of the excipient PEG 400 on the intestinal P-gp protein and mRNA levels, which has implications for oral drug absorption

There is a growing body of evidence which suggests that formerly regarded "inert" pharmaceutical excipients have the potential to influence oral drug bioavailability. The solubilizing agent polyethylene glycol 400 (PEG 400), for instance, has a sex-specific effect on P-glycoprotein (P-gp)-mediated drug bioavailability. We hypothesized that such an effect could be via PEG-induced alteration of P-gp activity and/or expression to different extents in males and females. To test this hypothesis in vivo, we investigated the influence of orally administered PEG 400 on the protein content and mRNA expression of P-gp in different regions of the gastrointestinal tract in male and female rats. Fasted rats received an oral dose of PEG 400 and at different time intervals, rats were sacrificed and their intestines were collected. The P-gp protein and mRNA expression in different intestinal segments (duodenum, jejunum, ileum and colon) were measured by Western blotting and PCR, respectively. It was found that P-gp protein and mRNA levels increased along the gastrointestinal tract in control animals (i.e. without PEG administration), and was higher in males compared to the female rats. The oral administration of PEG 400 decreased the P-gp expression in the jejunum, ileum and colon of males but not in the corresponding segments in females. This sex-dependent influence of PEG 400 on P-gp levels reflects and explains the sex-related effect of PEG 400 on oral absorption of certain drugs. The data further adds to the growing literature on the importance of taking into consideration an individual's sex for optimal drug administration.

Roles of ERα and ERβ in estrogen-induced DDP chemoresistance in non-small cell lung cancer

The role of estrogen in inducing chemoresistance is not yet fully understood. The objective of this study was to observe the relationship between estrogen levels and cellular response to chemotherapeutic drugs in non-small cell lung cancer (NSCLC) and to reveal the potential mechanisms involved. Cell viability was analyzed after pre-treating NSCLC cells with different levels of estrogen (E2), followed by treatment with an anti-tumor drug for 48 h. The roles of various estrogen receptors (ERs) were examined in vitro by blocking the activity of each ER individually. The ER pathway was further confirmed in NSCLC tissues. It was found that 10-1000 nM E2 resulted in a decreased cellular response to DDP in H1650 cells compared to the use of cisplatin alone (P < 0.05). However, this result was not demonstrated in H1299 cells, which lack p53. Both ERa and ERb were associated with E2-induced cisplatin chemoresistance, though they had opposite functions. p53 expression did not correlate with the expression of ERa or ERb individually. However, a statistically significant correlation between p53 expression and ERa to ERb mRNA ratio was observed (P < 0.001, R = -0.676). These findings suggest that E2-induced DDP chemoresistance depends on the balance between ERa and ERb expression and the p53 pathway.

Hepatoprotective effects of selenium during diabetes in rats

The present study investigated the hepatoprotective role of selenium during alloxan-induced diabetes in rats. Male Wistar rats were divided into four groups, namely, normal control, selenium treated, diabetic, and selenium-treated diabetic. Diabetes was induced in the animals by injecting alloxan intraperitoneally at a dose rate of 150 mg/kg body weight. Selenium in the form of sodium selenite was supplemented to rats at a dose level of 1 ppm in drinking water, ad libitum for two time durations of 2 and 4 weeks. The effects of different treatments were studied on various parameters in rat liver, which included serum glucose levels, serum insulin levels, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lipid peroxidation (LPO), glutathione reduced (GSH), oxidized glutathione (GSSG), total glutathione (TG), superoxide dismutase (SOD), catalase (CAT), glutathione reductase, glutathione peroxidase, metallothionein (MT), and histoarchitecture. A significant increase in the serum glucose levels, LPO levels, and in enzyme activities of ALP, ALT, and AST was observed in diabetic rats which, however, got decreased significantly upon supplementation with selenium. On the contrary, decreased enzyme activities of GSSG, SOD, and CAT and depressed levels of GSH as well as serum insulin levels were observed in diabetic rats which got improved following selenium supplementation. Interestingly, MT levels were increased both in diabetic and selenium-treated diabetic rats. Further, marked alterations in histoarchitecture were seen in diabetic rats with the prominent features being congestion in sinusoids, lipid accumulation, and centrilobular hepatocyte degeneration. However, selenium treatment to diabetic rats showed overall improvement in the hepatic histoarchitecture.

DAP12 deficiency in liver allografts results in enhanced donor DC migration, augmented effector T cell responses and abrogation of transplant tolerance

Liver interstitial dendritic cells (DC) have been implicated in immune regulation and tolerance induction. We found that the transmembrane immuno-adaptor DNAX-activating protein of 12 kDa (DAP12) negatively regulated conventional liver myeloid (m) DC maturation and their in vivo migratory and T cell allostimulatory ability. Livers were transplanted from C57BL/6(H2(b) ) (B6) WT or DAP12(-/-) mice into WT C3H (H2(k) ) recipients. Donor mDC (H2-K(b+) CD11c(+) ) were quantified in spleens by flow cytometry. Anti-donor T cell reactivity was evaluated by ex vivo carboxyfluorescein diacetate succinimidyl ester-mixed leukocyte reaction and delayed-type hypersensitivity responses, while T effector and regulatory T cells were determined by flow analysis. A threefold to fourfold increase in donor-derived DC was detected in spleens of DAP12(-/-) liver recipients compared with those given WT grafts. Moreover, pro-inflammatory cytokine gene expression in the graft, interferon gamma (IFNγ) production by graft-infiltrating CD8(+) T cells and systemic levels of IFNγ were all elevated significantly in DAP12(-/-) liver recipients. DAP12(-/-) grafts also exhibited reduced incidences of CD4(+) Foxp3(+) cells and enhanced CD8(+) T cell IFNγ secretion in response to donor antigen challenge. Unlike WT grafts, DAP12(-/-) livers failed to induce tolerance and were rejected acutely. Thus, DAP12 expression in liver grafts regulates donor mDC migration to host lymphoid tissue, alloreactive T cell responses and transplant tolerance.

Prospective feasibility study on the use of multiband mucosectomy for endoscopic resection of early squamous neoplasia in the esophagus

BACKGROUND AND STUDY AIMS

Endoscopic resection for esophageal squamous high-grade intraepithelial neoplasia (HGIN) or intramucosal cancer (esophageal squamous cell carcinoma [ESCC]) with the endoscopic resection cap technique is technically difficult, and requires submucosal lifting and multiple snares for piecemeal resections. Multiband mucosectomy (MBM) is an easy-to-use endoscopic resection technique and may be the modality of choice in China, where ESCC is extremely prevalent. The aim of the current study was to prospectively evaluate MBM for piecemeal endoscopic resection of squamous neoplasia of the esophagus.

METHODS

Patients with HGIN/ESCC and no signs of submucosal invasion or metastatic disease were included in the study. Lesions were delineated using electrocoagulation and resected using the MBM technique. Endpoints were procedure time, endoscopic radicality, complications, histology of the endoscopic resection specimens, and absence of HGIN/ESCC at the endoscopic resection scar during follow-up.

RESULTS

A total of 41 patients (26 male; mean age 61 years) underwent MBM; all lesions were visible with white light endoscopy (median length 5 cm, interquartile range [IQR] 4 - 6 cm; median circumferential extent 42 %, IQR 25 - 50 %). Median procedure time was 12 minutes (IQR 8 - 24 minutes). Median number of resections was 5 (IQR 3 - 6). Endoscopic complete resection was achieved in all lesions. There was one perforation, which was treated by application of clips. No other complications were observed. The worst histology was ESCC (n = 19), HGIN (n = 17), middle grade intraepithelial neoplasia (n = 4), and normal squamous epithelium (n = 1). Endoscopic follow-up at 3 months showed HGIN at the endoscopic resection scar in two patients, which was effectively treated endoscopically, and showed normal squamous epithelium in all patients at final follow-up (median 15 months, IQR 12 - 24 months).

CONCLUSION

This first prospective study on MBM for piecemeal endoscopic resection of early esophageal squamous neoplasia showed that MBM was effective for the complete removal of lesions with short procedure time, few complications, effective histological assessment of resected specimens, and durable treatment effect.

Randomized clinical trial comparing infrahepatic inferior vena cava clamping with low central venous pressure in complex liver resections involving the Pringle manoeuvre

BACKGROUND

Control of bleeding remains key to successful hepatic resection. The present randomized clinical trial compared infrahepatic inferior vena cava (IVC) clamping with low central venous pressure (CVP) during complex hepatectomy using portal triad clamping (PTC).

METHODS

Consecutive patients undergoing complex hepatectomy were allocated randomly to PTC combined with infrahepatic IVC clamping or to PTC with low CVP. Primary outcome was blood loss during parenchymal transection. Secondary outcomes were intraoperative surgical and haemodynamic parameters, postoperative recovery of liver and renal function, postoperative morbidity and mortality, and duration of hospital stay.

RESULTS

Between January 2008 and September 2010, 192 patients were randomized. Compared with low CVP, infrahepatic IVC clamping significantly decreased blood loss during parenchymal transection (mean(s.e.m.) 243(158) versus 372(197) ml; P < 0·001), was associated with faster recovery of liver function, and caused less impairment in renal function and fewer haemodynamic changes. The degree of cirrhosis correlated positively with CVP (R(2) = 0·963, P = 0·019) and with infrahepatic IVC pressure (R(2) = 0·950, P = 0·025). For patients with moderate or severe cirrhosis, infrahepatic IVC clamping was more efficacious in controlling blood loss during parenchymal transection (mean(s.e.m.) 2·9(1·8) versus 6·1(2·4) ml/cm(2); P < 0·001).

CONCLUSION

PTC combined with infrahepatic IVC clamping is more efficacious in controlling bleeding during complex hepatectomy than PTC with low CVP, especially in patients with moderate to severe cirrhosis.

REGISTRATION NUMBER

NCT01355887 (http://www.clinicaltrials.gov).

Levels of circulating endothelial progenitor cells are related to uremic toxins and vascular injury in hemodialysis patients

BACKGROUND

Patients suffering from chronic kidney diseases (CKD) exhibit cardiovascular diseases and profound endothelial dysfunction. CKD patients have reduced numbers of endothelial progenitor cells, but little is known about the factors influencing these numbers.

OBJECTIVES

Among these factors, we hypothesized that uremic toxins and vascular injury affect endothelial progenitor cells.

PATIENTS/METHODS

Thirty-eight hemodialysis patients were investigated and compared with 21 healthy controls. CD34+CD133+ immature progenitors, CD34+KDR+ endothelial progenitors cells (EPC) and myeloid EPC (mEPC) were counted in peripheral blood. Levels of uremic toxins beta(2)-microglobulin, indole-3 acetic acid, indoxylsulfate, p-cresylsulfate and homocysteine were measured. Vascular injury was assessed in hemodialysis (HD) patients by measuring aortic pulse wave velocity and plasma levels of endothelial microparticles. In vitro experiments were performed to study the effect of uremic toxins on apoptosis of progenitor cells.

RESULTS AND CONCLUSIONS

CD34+CD133+ immature progenitor cell number was negatively correlated with the levels of uremic toxins beta(2)-microglobulin and indole-3 acetic acid. In vitro, indole-3 acetic acid induced apoptosis of CD133+ cells. These data indicate uremic toxins have a deleterious role on progenitor cells, early in the differentiation process. Moreover, mEPC number was positively correlated with markers of vascular injury-pulse wave velocity and endothelial microparticle levels. This suggests that vascular lesions could stimulate progenitor cell mobilization, even in a context of reduced EPC induced by CKD. In conclusion, uremic toxins and vascular injury appear to affect endothelial progenitor cell biology in CKD.

The uremic solute indoxyl sulfate induces oxidative stress in endothelial cells

BACKGROUND

Endothelial dysfunction and oxidative stress are matters of concern in patients with chronic renal failure (CRF). Uremic solutes retained in these patients could be involved in these processes. Notably, the protein-bound uremic solute indoxyl sulfate induces endothelial dysfunction in vitro, and has shown pro-oxidant effects.

OBJECTIVE

To demonstrate that indoxyl sulfate is a potential mediator of oxidative stress in endothelial cells in vitro.

METHODS

Indoxyl sulfate-induced oxidative stress in human umbilical vein endothelial cells (HUVEC) was studied by measuring reactive oxygen specie (ROS) production by cytofluorimetry, by analyzing the involvement of the pro-oxidative enzymes NAD(P)H oxidase, xanthine oxidase, and NO synthase, and by measuring the levels of the non-enzymatic antioxidant glutathione.

RESULTS

We showed that indoxyl sulfate induced a significant production of ROS in HUVEC, with or without human serum albumin. We then investigated the role of pro-oxidative enzymes and measured the levels of the antioxidant glutathione. The NAD(P)H oxidase inhibitors, DPI, and apocynin, inhibited ROS production, whereas inhibitors of xanthine oxidase, NO synthase, and mitochondrial ROS had no effect. Interestingly, indoxyl sulfate strongly decreased the levels of glutathione, one of the most active antioxidant systems of the cell. In addition, the ROS production mediated by indoxyl sulfate was inhibited by the antioxidants vitamin C, vitamin E, and NAC.

CONCLUSION

The uremic solute indoxyl sulfate enhances ROS production, increases NAD(P)H oxidase activity, and decreases glutathione levels in endothelial cells. Thus, indoxyl sulfate induces oxidative stress by modifying the balance between pro- and antioxidant mechanisms in endothelial cells.

Elevation of circulating endothelial microparticles in patients with chronic renal failure

BACKGROUND

Chronic renal failure patients are at high risk of cardiovascular events and display endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis. Upon activation, the endothelium sheds microparticles, considered as markers of endothelial dysfunction that also behave as vectors of bioactive molecules.

AIM

To measure plasma levels of endothelial microparticles (EMPs) in chronic renal failure patients (CRF), either undialyzed or hemodialyzed (HD), and to investigate the ability of uremic toxins to induce EMP release in vitro.

METHODS

Circulating EMPs were numerated by flow cytometry, after staining of platelet-free plasma with phycoerythrin (PE)-conjugated anti-CD144 (CD144+ EMP) or anti-CD146 (CD146+ EMP) monoclonal antibodies. Platelet MP (CD41+ PMP), leukocyte MP (CD45+ leukocyte microparticles (LMP)), and annexin-V+ MPs were also counted. In parallel, MPs were counted in supernatant of human umbilical vein endothelial cells incubated with uremic toxins [oxalate, indoxyl sulfate, p-cresol, and homocysteine (Hcy)], at concentrations found in patients.

RESULTS AND CONCLUSIONS

CD144+ EMP and CD146+ EMP levels were significantly higher in CRF and HD patients than in healthy subjects. Furthermore, annexin-V+ MPs were elevated in both groups of uremic patients, and CD41+ PMP and CD45+ LMP were increased in CRF and HD patients, respectively. In vitro, p-cresol and indoxyl sulfate significantly increased both CD146+ and annexin-V+ EMP release. Increased levels of circulating EMP in CRF and HD patients represent a new marker of endothelial dysfunction in uremia. The ability of p-cresol and indoxyl sulfate to increase EMP release in vitro suggests that specific uremic factors may be involved in EMP elevation in patients.

Elevation of circulating endothelial microparticles in patients with chronic renal failure

BACKGROUND

Chronic renal failure patients are at high risk of cardiovascular events and display endothelial dysfunction, a critical element in the pathogenesis of atherosclerosis. Upon activation, the endothelium sheds microparticles, considered as markers of endothelial dysfunction that also behave as vectors of bioactive molecules.

AIM

To measure plasma levels of endothelial microparticles (EMPs) in chronic renal failure patients (CRF), either undialyzed or hemodialyzed (HD), and to investigate the ability of uremic toxins to induce EMP release in vitro.

METHODS

Circulating EMPs were numerated by flow cytometry, after staining of platelet-free plasma with phycoerythrin (PE)-conjugated anti-CD144 (CD144+ EMP) or anti-CD146 (CD146+ EMP) monoclonal antibodies. Platelet MP (CD41+ PMP), leukocyte MP (CD45+ leukocyte microparticles (LMP)), and annexin-V+ MPs were also counted. In parallel, MPs were counted in supernatant of human umbilical vein endothelial cells incubated with uremic toxins [oxalate, indoxyl sulfate, p-cresol, and homocysteine (Hcy)], at concentrations found in patients.

RESULTS AND CONCLUSIONS

CD144+ EMP and CD146+ EMP levels were significantly higher in CRF and HD patients than in healthy subjects. Furthermore, annexin-V+ MPs were elevated in both groups of uremic patients, and CD41+ PMP and CD45+ LMP were increased in CRF and HD patients, respectively. In vitro, p-cresol and indoxyl sulfate significantly increased both CD146+ and annexin-V+ EMP release. Increased levels of circulating EMP in CRF and HD patients represent a new marker of endothelial dysfunction in uremia. The ability of p-cresol and indoxyl sulfate to increase EMP release in vitro suggests that specific uremic factors may be involved in EMP elevation in patients.

RAD in stable lung and heart/lung transplant recipients: safety, tolerability, pharmacokinetics, and impact of cystic fibrosis

BACKGROUND

RAD is a novel macrolide with potent immunosuppressive and antiproliferative activities. This study characterizes the safety, tolerability, and pharmacokinetics of two different single oral doses of RAD in stable lung and heart/lung transplant recipients with and without cystic fibrosis (CF).

METHODS

This was a Phase I, multicenter, randomized, double-blind, two-period, two-sequence, crossover study. Single doses of RAD capsules at doses of 0.035 mg/kg (2.5 mg maximum) or 0.10 mg/kg (7.5 mg maximum) were administered with cyclosporine (Neoral [cyclosporine, USP] modified), steroids, and azathioprine on Day 1. The alternate dose was administered on Day 16. Laboratory assessments, vital signs, and adverse events were recorded throughout the study. RAD pharmacokinetic profiles were assessed over a 7-day period following each dose. Steady-state cyclosporine (CsA) profiles were assessed at baseline and with each RAD dose; RAD and CsA trough concentrations were obtained throughout the study period.

RESULTS

Of the 20 patients randomized, 8 had CF and 12 did not. Single doses of RAD were safe and well tolerated. Headache was the most common side effect. RAD produced a mild, dose-dependent, reversible decrease in platelet and leukocyte counts. Cholesterol and triglycerides were minimally affected. At both doses, CF patients had significantly lower peak concentrations of RAD than did non-CF patients (p = 0.03); however, overall exposure (area under the curve/dose) was not different between the groups (p = 0.63). At the higher dose, there was a clinically minor under-proportionality in AUC, averaging -11%. Steady-state pharmacokinetics of CsA were not affected by RAD co-administration.RAD was safe and well tolerated by stable lung and heart/lung transplant recipients with and without CF. The presence of CF did not influence the extent of RAD exposure. Single doses of RAD did not affect the pharmacokinetics of CsA. Ongoing studies are assessing the long-term safety and efficacy of RAD in lung and heart/lung transplantation.

[Generation of monoclonal antibody Fab fragments to parathyroid hormone related protein by phage display technology]

OBJECTIVE

To develop monoclonal antibody Fab fragments using display technique.

METHODS

The mouse IgG Fab genes of heavy and light chains were amplified from spleen cells of a parathyroid hormone-related protein (PTHrP) immunized mouse. The combinatorial phage antibody library was prepared by inserting both heavy and light chain Fab genes into phagemid vector pComb3 and followed by infection of helper phage. The library was selected by purified recombinant PTHrP.

RESULTS

The combinatorial phage antibody library was constructed successfully and the specific mouse Fabs to PThrP were selected and expressed in E. coli.

CONCLUSIONS

The selected specific mouse Fabs can recognize PTHrP with high specificity.

Cloning and expression of truncated PTHrP receptor in Escherichia coli

To evaluate the effects of recombinant soluble parathyroid hormone related protein receptor(sPTHrPR), the RNA prepared from renal cell carcinoma was reverse-transcribed and amplified by a polymerase chain reaction(PCR). A 543 base pair fragment corresponding to extracellular domain of PTHrPR was obtained and cloned. Sequencing was performed by the dideoxy chain-termination method. Comparison of the nucleic acid sequence with the published data revealed that only one nucleotide had changed. A high level expression vector referred to as pET-3a/sPTHrPR was constructed. The binding specificity of the expression products was proved by indirect ELISA. Our preliminary experiment also showed that the expression products can block the biological activity of PTHrP.