Drug eluting biliary stents to decrease stent failure rates: A review of the literature

Biliary stenting is clinically effective in relieving both malignant and non-malignant obstructions. However, there are high failure rates associated with tumor ingrowth and epithelial overgrowth as well as internally from biofilm development and subsequent clogging. Within the last decade, the use of prophylactic drug eluting stents as a means to reduce stent failure has been investigated. In this review we provide an overview of the current research on drug eluting biliary stents. While there is limited human trial data regarding the clinical benefit of drug eluting biliary stents in preventing stent obstruction, recent research suggests promise regarding their safety and potential efficacy.     

Placental protein 13 (galectin-13) has decreased placental expression but increased shedding and maternal serum concentrations in patients presenting with preterm pre-eclampsia and HELLP syndrome

Placental protein 13 (PP13) is a galectin expressed by the syncytiotrophoblast. Women who subsequently develop preterm pre-eclampsia have low first trimester maternal serum PP13 concentrations. This study revealed that third trimester maternal serum PP13 concentration increased with gestational age in normal pregnancies (p < 0.0001), and it was significantly higher in women presenting with preterm pre-eclampsia (p = 0.02) and hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome (p = 0.01) than in preterm controls. Conversely, placental PP13 mRNA (p = 0.03) and protein, as well as cytoplasmic PP13 staining of the syncytiotrophoblast (p < 0.05) was decreased in these pathological pregnancies compared to controls. No differences in placental expression and serum concentrations of PP13 were found at term between patients with pre-eclampsia and control women. In contrast, the immunoreactivity of the syncytiotrophoblast microvillous membrane was stronger in both term and preterm pre-eclampsia and HELLP syndrome than in controls. Moreover, large syncytial cytoplasm protrusions, membrane blebs and shed microparticles strongly stained for PP13 in pre-eclampsia and HELLP syndrome. In conclusion, parallel to its decreased placental expression, an augmented membrane shedding of PP13 contributes to the increased third trimester maternal serum PP13 concentrations in women with preterm pre-eclampsia and HELLP syndrome.     

The impact of COVID-19 on home,social, and productivity integration of people with chronic traumatic brain injury or stroke living in the community

Compare community integration of people with stroke or traumatic brain injury (TBI) living in the community before and during the coronavirus severe acute respiratory syndrome coronavirus 2 disease (COVID-19) when stratifying by injury: participants with stroke (G1) and with TBI (G2); by functional independence in activities of daily living: independent (G3) and dependent (G4); by age: participants younger than 54 (G5) and older than 54 (G6); and by gender: female (G7) and male (G8) participants.Prospective observational cohort studyIn-person follow-up visits (before COVID-19 outbreak) to a rehabilitation hospital in Spain and on-line during COVID-19.Community dwelling adults (≥18 years) with chronic stroke or TBI.Community integration questionnaire (CIQ) the total-CIQ as well as the subscale domains (ie, home-CIQ, social-CIQ, productivity CIQ) were compared before and during COVID-19 using the Wilcoxon ranked test or paired t test when appropriate reporting Cohen effect sizes (d). The functional independence measure was used to assess functional independence in activities of daily living.Two hundred four participants, 51.4% with stroke and 48.6% with TBI assessed on-line between June 2020 and April 2021 were compared to their own in-person assessments performed before COVID-19.When analyzing total-CIQ, G1 (d = −0.231), G2 (d = −0.240), G3 (d = −0.285), G5 (d = −0.276), G6 (d = −0.199), G7 (d = −0.245), and G8 (d = −0.210) significantly decreased their scores during COVID-19, meanwhile G4 was the only group with no significant differences before and during COVID-19.In productivity-CIQ, G1 (d = −0.197), G4 (d = −0.215), G6 (d = −0.300), and G8 (d = −0.210) significantly increased their scores, meanwhile no significant differences were observed in G2, G3, G5, and G7.In social-CIQ, all groups significantly decreased their scores: G1 (d = −0.348), G2 (d = −0.372), G3 (d = −0.437), G4 (d = −0.253), G5 (d = −0.394), G6 (d = −0.319), G7 (d = −0.355), and G8 (d = −0.365).In home-CIQ only G6 (d = −0.229) significantly decreased, no significant differences were observed in any of the other groups.The largest effect sizes were observed in total-CIQ for G3, in productivity-CIQ for G6, in social-CIQ for G3 and in home-CIQ for G6 (medium effect sizes).Stratifying participants by injury, functionality, age or gender allowed identifying specific CIQ subtotals where remote support may be provided addressing them.     

Substance P-like immunoreactive fibres in the ventromedial mesencephalic tegmentum of rat

The distribution and morphology of the substance P-like immunoreactive (SP-IR) fibres and terminals in the rat ventromedial mesencephalic tegmentum (VMT) were studied using qualitative and quantitative immunohistochemical methods at light and electron microscopic levels. All five component nuclei of the VMT were examined and the size, number and density of immunoreactive terminals determined. The SP-IR fibres were distributed heterogeneously within the VMT. Under the electron microscope, SP-IR axon terminals contained both clear and dense-cored vesicles and made both symmetrical and asymmetrical synapses. The ultrastructure of the SP-IR terminals appeared to differ between nuclei. Small, clear vesicle terminals made symmetrical synaptic junctions with small calibre dendrites in the paranigral nucleus while large, clear and dense-cored vesicle terminals made asymmetrical junctions with somata and large calibre dendrites in the interfascicular nucleus. Quantitative differences between the VMT nuclei were also seen in the density of SP-IR terminals, the paranigral nucleus contained the highest density and the rostral linear nucleus the lowest. A comparison between the number of SP-IR terminals and the total number of axon terminals in the VMT reveals that the majority of all terminals in the paranigral nucleus were SP-IR, as well as the majority of axosomatic synapses in the interfascicular nucleus. These regional differences in the SP-IR innervation suggest that substance P and related peptides may perform several specific functions within the VMT and therefore have a more variable influence on this region than was previously thought.     

Platelet activation and hypercoagulability following treatment with porcine factor VIII (HYATE:C)

Activation of platelets and coagulation in vivo was studied in nine patients with hemophilia A and inhibitors to human Factor VIII, prior to and following treatment with porcine Factor VIII (PFVIII; HYATE:C). In addition, six hemophiliac patients were similarly studied after treatment with recombinant Factor VIII (rFVIII). Platelet activation was also examined in vitro using porcine von Willebrand factor (PvWF)-enriched and PvWF-depleted fractions obtained by fractionation of PFVIII. Coagulation was assessed by measuring the concentrations of plasma prothrombin fragment 1+2 concentrations (prothrombinase generation) and Factor Xa-ATIII. Patients treated with PFVIII had significantly increased numbers of circulating platelets expressing CD62 and CD63 (markers of platelet activation) and annexin V (marker of platelet procoagulant activity) compared to patients treated with rFVIII; the former patients also demonstrated an increase in plasma coagulability after therapy. In in vitro experiments it was observed that the platelet-activating and procoagulant capacity of PFVIII resided in the PvWF-enriched fraction, and the same was true for the plasma hypercoagulability following exposure of platelets to PFVIII. These results support the hypothesis that PFVIII-induced platelet activation provides a mechanism for enhancing hemostasis, separate from, and additional to, that due to increased circulating Factor VIII, and it is due to residual PvWF in the PFVIII preparation.     

Effects of EGIS-7625, a Selective and Competitive 5-HT2B Receptor Antagonist

Our aim was to specify the 5-HT(2) subtype selectivity of EGIS-7625 (1-benzyl-4-[(2-nitro-4-methyl-5-amino)-phenyl]-piperazine), a new 5-HT(2B) ligand, in receptor binding studies and characterize its pharmacology at 5-HT(2A), 5-HT(2B) and 5-HT(2C) receptors in in vivo experiments and in isolated organs, in vitro. EGIS-7625 had high affinity for recombinant human 5-HT(2B) receptors (pK(i) = 9.0) but much weaker affinity for 5-HT(2A) and 5-HT(2C) receptors (pK(i) = 6.2 and 7.7, respectively). In the classic 5-HT(2B) test, EGIS-7625 produced a concentration-related parallel rightward shift in the concentration-response relationship for the 5-HT-induced smooth muscle constriction in rat stomach fundus strips with a pA(2) of 9.4. On the other hand, EGIS-7625 was a weak competitive antagonist at 5-HT(2A) receptors as it shifted 5-HT-induced concentration-response curves to the right at high concentrations (pA(2) = 6.7) in rabbit pulmonary artery strips. The m-chlorophenylpiperazine-induced hypomotility and hypophagia was only partially attenuated by EGIS-7625 even at a dose of 30 mg/kg i.p. while mianserin, a non-selective 5-HT antagonist was almost fully effective in these tests at 3 mg/kg i.p., suggesting weak antagonistic effect of EGIS-7625 at neuronal 5-HT(2C) receptors, in vivo. In conclusion, EGIS-7625 is a potent, selective and competitive 5-HT(2B) antagonist that seems to be a good research tool for the separation of the functional roles of vascular 5-HT(2A) and 5-HT(2B) receptors.     

Functional analysis of the p53 codon 72 polymorphism in black South Africans with rheumatoid arthritis—a pilot study

The p53 tumor-suppressor protein plays an integral role in apoptosis. Perturbations in peripheral lymphocyte (PL) apoptosis may be associated with rheumatoid arthritis (RA). Polymorphisms at codon 72 of p53 (arginine (Arg72) to proline transition) confers differences in mitochondrial translocation and apoptosis inducing capabilities of p53 in vitro. We examined associations of this polymorphism with PL apoptosis, mitochondrial depolarization, and clinical markers of disease activity in a cohort of black South African RA patients. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. PL apoptosis was measured using the annexin-V assay and mitochondrial membrane potential with the JC-1 assay. Clinical and laboratory parameters were recorded for all patients. Statistical differences in these parameters were investigated according to genotype. Genotype distribution did not differ significantly between RA patients and controls (Arg/Arg, Arg/Pro, Pro/Pro: 12%, 46%, and 42% versus 3%, 34%, and 63%), despite significantly higher frequency of the Arg72 allele in patients (p = 0.0406). There was no significant difference in PL apoptosis and mitochondrial depolarization based on p53 codon 72 genotype. In addition, clinical markers of disease activity were not significantly different between genotypes. We conclude that p53 codon 72 genotype does not influence PL apoptosis or mitochondrial depolarization and is not associated with clinical markers of disease in RA.     

A Phase II,open-label,randomised study to assess the efficacy and safety of the MEK1/2 inhibitor AZD6244 (ARRY-142886) versus capecitabine monotherapy in patients with colorectal cancer who have failed one or two prior chemotherapeutic regimens

Objectives To assess the efficacy and safety of the MEK1/2 inhibitor AZD6244 (ARRY-142886) in patients with metastatic colorectal cancer who had failed one or two previous chemotherapeutic regimens that included oxaliplatin and/or irinotecan. Methods This was a Phase II, multicentre, open-label, randomised, two-arm, parallel-group study comparing AZD6244 with capecitabine monotherapy. Patients received either 100 mg twice daily oral AZD6244 free-base suspension every day or 1,250 mg/m² twice daily oral capecitabine, for 2 weeks, followed by a 1-week rest period, in 3-weekly cycles. The primary endpoint was the number of patients experiencing disease progression events. Results Sixty-nine patients were randomised in the study (34 and 35 patients in the AZD6244 and capecitabine groups, respectively). Disease progression events were experienced by 28 patients (∼80%) in both the AZD6244 and capecitabine treatment groups. Median progression-free survival was 81 days and 88 days in the AZD6244 and capecitabine groups, respectively. Ten patients in the AZD6244 treatment arm had a best response of stable disease. For capecitabine, best response was a partial response in one patient, with stable disease in a further 15 patients. The most frequently observed adverse events reported with AZD6244 were acneiform dermatitis, diarrhoea, asthenia and peripheral oedema, compared with hand-foot syndrome, diarrhoea, nausea and abdominal pain with capecitabine. Conclusions AZD6244 showed similar efficacy to capecitabine in terms of the number of patients with a disease progression event and of progression-free survival. AZD6244 is currently undergoing evaluation in Phase II trials in combination with other chemotherapeutic agents.     

Recurring transitory blindness caused by primary marginal pigment epithelial iris cysts

PURPOSE: To report four cases of primary pupillary pigment epithelial iris cysts, all members of one family, in which two of the patients had recurring transitory visual impairment. METHODS: Observational case series. History was taken, the patients were examined with slit-lamp and ultrasound biomicroscopy, and surgically removed cyst tissue was examined with transmission electron microscopy. RESULTS: Pupillary pigment epithelial cysts of the iris generally show an autosomal dominant heredity pattern, with occasional lack of penetrance. In two of our cases, the size and location of the cysts caused visual symptoms, necessitating surgical removal. The cyst wall consists entirely of pigment epithelial cells. CONCLUSION: The origin of pupillary pigment epithelial cysts is unclear, and a hereditary background is very likely. Their clinical significance is in their similarity to pigmented tumors of the iris. They may also be indicative of coexisting systemic disease. In symptomatic cases, treatment is indicated.