Receptors and ligands role in colon physiology and pathology

Biopharmaceutical insights of particulate emulsified systems - a prospective overview

During the twenty-first century, drug discovery is expanding rapidly and a large number of chemical moieties are recognized. Many of them are poorly soluble and hence related biopharmaceutical constraints are to be addressed systematically. Among novel approaches to resolving biopharmaceutical issues, micro- and nano-emulsified systems serve as the best strategy for delivering both hydrophobic and hydrophilic drugs owing to their greater solubilization and transportation capabilities. Of late, the unique physical and biopharmaceutical properties of these liquid isotropic homogenous systems have gained substantive research importance. In addition nano/micro lipid systems share structural and functional similarity with that of the physiological lipids which offer better tolerance ability in the body. In this context, this article provides information on the historical emergence of particulate emulsified systems, importance and rationale of selection of carriers. It also encompasses the physicochemical principles that are responsible for the elevation of therapeutic outcomes of delivery systems. Detailed and schematic absorption of these drug delivery systems is explained here. Gastro-intestinal biochemistry necessary in the understanding of digestion process, lipolytic products formed, micellar structures, enzymes, transporters, mechanism of cell uptake involved after subsequent oral absorption are also emphasized. In addition, this article also explains disposition and pharmacokinetic properties of emulsified systems with real-time therapeutic research outcomes. The influence of biochemical compositions and biopharmaceutical principles on absorption and disposition patterns of ME/NEs was described in the article for the interest of readers and young researchers.

Clopidogrel IBS Patients Have Higher Incidence of Gastrointestinal Symptoms Influenced by Age and Gender

BACKGROUND

Clopidogrel is an irreversible antagonist of P2Y₁₂ receptors (P2Y₁₂Rs) used as an antiplatelet drug to reduce risk of thrombosis. P2Y₁₂Rs are expressed in gastrointestinal (GI) tract where they might regulate GI function.

AIM

To evaluate if blockade of P2Y₁₂Rs by clopidogrel is associated with higher incidence of GI symptoms in patients with irritable bowel syndrome (IBS).

METHODS

A retrospective analysis of our institutional database was conducted for a 13-year period. IBS patients were identified, and their demographics, GI symptoms and clopidogrel therapy were collected. Logistic regression models were used to characterize symptoms in clopidogrel versus no-clopidogrel IBS-groups, adjusting for Age and Sex differences. An additional study characterized the P2Y₁₂R distribution in human gut.

RESULTS

The search identified 7217 IBS patients (6761 no-clopidogrel/456 clopidogrel). There were a higher proportion of patients with GI symptoms on clopidogrel (68%) compared to controls (60%, p = 0.0011) that were Females (70 vs. 60%, p = 0.0003) not Males (61 vs. 60%; p = 0.8312). In Females, clopidogrel was associated with higher incidence of GI symptoms (Age adjusted; p < 0.0001) for pain, constipation, gastroparesis (p ≤ 0.0001) and psychogenic pain (p = 0.0006). Age or Sex (adjusted models) influenced one or more GI symptoms (i.e., pain, p < 0.0001; constipation, p < 0.0001/p = 0.008; diarrhea, flatulence, p = 0.01). P2Y₁₂R immunoreactivity was abundant in human ENS; glial-to-neuron ratio of P2Y₁₂Rs expressed in Females ≫ Males.

CONCLUSIONS

Irreversible blockade of P2Y₁₂R by clopidogrel is associated with higher incidence of GI symptoms in Female IBS patients, although Age or Sex alone contributes to symptomatology. Prospective studies can determine clinical implications of P2Y₁₂Rs in IBS.

The Frequency and Type of K-RAS Mutations in Mexican Patients With Colorectal Cancer: A National Study

BACKGROUND

Current metastatic colorectal cancer (mCRC) therapy uses monoclonal antibodies against the epidermal growth factor receptor. This treatment is only useful in the absence of K-RAS gene mutations; therefore the study of such mutations is part of a personalized treatment. The aim of this work is to determine the frequency and type of the most common K-RAS mutations in Mexican patients with metastatic disease by nucleotide sequencing.

PATIENTS AND METHODS

We studied 888 patients with mCRC from different regions of Mexico. The presence of mutations in exon 2, codons 12 and 13, of the K-RAS gene was determined by nucleotide sequencing.

RESULTS

Patients exhibited K-RAS gene mutations in 35% (310/888) of cases. Mutation frequency of codons 12 and 13 was 71% (221/310) and 29% (89/310), respectively. The most common mutation (45.7%) in codon 12 was c.35G>A (p.G12D), whereas the one in codon 13 was c.38G>A (p.G13D) (78.7%).

DISCUSSION

Given the frequency of K-RAS mutations in Mexicans, making a genetic study before deciding to treat mCRC patients with monoclonal antibodies is indispensable.

The signaling pathway of stromal cell-derived factor-1 and its role in kidney diseases

The chemokine stromal cell-derived factor-1 (SDF-1) regulates the trafficking of progenitor cell (PGC) during embryonic development, cell chemotaxis, and postnatal homing into injury sites. SDF-1 also regulates cell growth, survival, adhesion and angiogenesis. However, in different tissues/cells, the role of SDF-1 is different, such as that it is increased in most of the tumors and associated with cancer metastasis, whereas it is essential for the development of vasculature. For kidney diseases, its role remains controversial. Signaling pathways might be very important in the pathogenesis of kidney diseases. We performed this review to provide a relatively complete signaling pathway flowchart for SDF-1 to the investigators who were interested in the role of SDF-1 in the pathogenesis of kidney diseases. Here, we reviewed the signal transduction pathway of SDF-1 and its role in the pathogenesis of kidney diseases.