Hepatic immunosuppressive effects of systemically administered novel dextran-methylprednisolone prodrugs with peptide linkers in rats

The hepatic immunosuppressive activities of two novel dextran prodrugs of methylprednisolone (MP) containing one (DMP1) or five (DMP5) amino acids as linkers were studied in rats. At various times (0–2 weeks) after intravenous administration of single 5 mg/kg (MP equivalent) doses of each prodrug or MP succinate (MPS), livers were isolated and immunologically stimulated ex vivo with lipopolysaccharide. The concentrations of tumor necrosis factor (TNF)‐α in the outlet perfusate were then quantitated to assess immune response. Additionally, the concentrations of DMP1, DMP5, and/or MP were measured in the liver. MPS, DMP5, or DMP1 injections caused a maximum of 48.9%, 63.5%, or 85.7% decrease in the TNF‐α secretion into the perfusate, with the time above the 50% inhibitory effect being <5, <24, or 120 h, respectively. Additionally, the area under the effect–time curve for DMP1 was 11‐fold or fourfold higher than that after the administration of MPS or DMP5, respectively. Relatively high concentrations of DMP1 were present in the liver even at the last sampling time of 2 weeks. These data suggest that a single intravenous dose of DMP1 produces an intense and sustained immunosuppression in the liver for a relatively long time, which may be useful in liver transplantation.     

Effects of Hepatic Ischemia-Reperfusion Injury on the P-Glycoprotein Activity at the Liver Canalicular Membrane and Blood–Brain Barrier Determined by In Vivo Administration of Rhodamine 123 in Rats

Purpose

To investigate the effects of normothermic hepatic ischemia-reperfusion (IR) injury on the activity of P-glycoprotein (P-gp) in the liver and at the blood–brain barrier (BBB) of rats using rhodamine 123 (RH-123) as an in vivo marker.

Methods

Rats were subjected to 90 min of partial ischemia or sham surgery, followed by 12 or 24 h of reperfusion. Following intravenous injection, the concentrations of RH-123 in blood, bile, brain, and liver were used for pharmacokinetic calculations. The protein levels of P-gp and some other transporters in the liver and brain were also determined by Western blot analysis.

Results

P-gp protein levels at the liver canalicular membrane were increased by twofold after 24 h of reperfusion. However, the biliary excretion of RH-123 was reduced in these rats by 26%, presumably due to IR-induced reductions in the liver uptake of the marker and hepatic ATP concentrations. At the BBB, a 24% overexpression of P-gp in the 24-h IR animals was associated with a 30% decrease in the apparent brain uptake clearance of RH-123. The pharmacokinetics or brain distribution of RH-123 was not affected by the 12-h IR injury.

Conclusions

Hepatic IR injury may alter the peripheral pharmacokinetics and brain distribution of drugs that are transported by P-gp and possibly other transporters.     

The Rise of Electronic Health Record Adoption Among Family Physicians

PURPOSE

Realizing the benefits of adopting electronic health records (EHRs) in large measure depends heavily on clinicians and providers’ uptake and meaningful use of the technology. This study examines EHR adoption among family physicians using 2 different data sources, compares family physicians with other office-based medical specialists, assesses variation in EHR adoption among family physicians across states, and shows the possibility for data sharing among various medical boards and federal agencies in monitoring and guiding EHR adoption.

METHOD

We undertook a secondary analysis of American Board of Family Medicine (ABFM) administrative data (2005–2011) and data from the National Ambulatory Medical Care Survey (NAMCS) (2001–2011).

RESULTS

The EHR adoption rate by family physicians reached 68% nationally in 2011. NAMCS family physician adoption rates and ABFM adoption rates (2005–2011) were similar. Family physicians are adopting EHRs at a higher rate than other office-based physicians as a group; however, significant state-level variation exists, indicating geographical gaps in EHR adoption.

CONCLUSION

Two independent data sets yielded convergent results, showing that adoption of EHRs by family physicians has doubled since 2005, exceeds other office-based physicians as a group, and is likely to surpass 80% by 2013. Adoption varies at a state level. Further monitoring of trends in EHR adoption and characterizing their capacities are important to achieve comprehensive data exchange necessary for better, affordable health care.     

HIV/AIDS risk behaviors and correlates of injection drug use among drug users in Pakistan

We studied prevalence and correlates of injection drug use, awareness of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), and risky behaviors among drug users serviced by a nongovernmental organization catering to drug users in three Pakistani cities (Quetta, Peshawar, and Rawalpindi). Logistic regression analysis was used to identify correlates of injection drug use. Of 608 drug users, 99.8% were male; median age was 32 years, and 44% were married. Most (79.8%) were Pakistani; 15.3% were Afghani. The majority used heroin (98.7%), mostly by inhalation; 15.2% injected drugs. Only 41% had heard of HIV/AIDS, and 30% had been paid for donating blood. Injection drug use and needle sharing were highest in Quetta. Injecting drug users (IDUs) were nearly twice as likely to have donated blood and to have heard about HIV/AIDS compared to other drug users. Interventions to discourage transitions to injection, increase HIV testing, and safeguard the blood supply in Pakistan are urgently needed.     

Influence of the use of phosphate binders on serum levels of calcium phosphate in patients with chronic kidney disease undergoing hemodialysis: A retrospective and prospective study

Hypercalcemia–hyperphosphatemia is an unavoidable consequence of end-stage chronic kidney disease and common in hemodialytic patients. Calcium carbonate (CaCO₃) is one type of phosphate binder used widely and prescribed in patients undergoing hemodialysis, aiming to control the levels of calcium and phosphate. These drugs are most effective if taken with meals. This study aimed to evaluate the use of phosphate binders in hemodialysis patients and the factors that influence the success of phosphate binder therapy by experimental studies with retrospective data collection through the medical records and prospectively through the questionnaire and interviews with patients. The research was conducted in the Unit Hemodialysis building floor 8 of Cipto Mangunkusumo Hospital, Jakarta. The data were collected in a retrospective way for two months (January–February 2013) and a prospective study in March–April 2013. Patients included were stage 5 chronic kidney disease patients who underwent hemodialysis in hemodialysis ward of Cipto Mangunkusumo Hospital. Patients who had data of serum levels at the beginning of the use of calcium phosphate and the final data in 2013 got the phosphate binder therapy.

Results

Ninety six patients with stage 5 chronic kidney disease who underwent hemodialysis had been using phosphate binder for 3 years in average. Patient evaluation showed that hypocalcemia was obtained in 23%; normokalemia in 42.7% and hypercalcemia in 34.3%. While the percentage of patients with hipofosfatemia14, 6%, normofosfatemia 32.3% and 53.1% hyperphosphatemia. Results obtained by the prospective analysis of factors that affect the success of the use of phosphate binder therapy are related to how the routine use of phosphate binders is made by the patient. Chi square test showed a significance of 0.000 (p < 0.05), the effect of 54%.

Conclusion

We can conclude there are many events happening such as hyperphosphatemia in hemodialysis patients that use phosphate binders. Monitoring of serum levels of calcium phosphate in patients with chronic kidney disease undergoing hemodialysis should be performed every month. Education and the role of clinical staff required to assist compliance and therapeutic efficacy of phosphate binder are necessary.     

Preparation and in vitro evaluation of thiolated chitosan microparticles

The objective of this study was to prepare a microparticulate drug delivery system being based on a new thiomer, namely a chitosan 2-iminothiolane conjugate (chitosan-TBA conjugate). Due to thiol groups being immobilized on chitosan, chitosan-TBA conjugate exhibits improved mucoadhesive and permeation enhancing properties. Because of these features microparticulate drug delivery systems based on chitosan-TBA conjugate might be a promising tool for the non-invasive administration of hydrophilic macromolecular drugs. Chitosan-TBA conjugate microspheres were prepared by the emulsification/solvent evaporation method. Fluorescein-isothiocyanate labelled dextran (FITC-dextran) was chosen as a model hydrophilic drug. Microspheres have been characterized by morphological analysis, thiol group content, swelling behaviour, polymer degradation drug load determination, dissolution test and mucoadhesion studies. Results reported in this work demonstrated the possibility to obtain stable microspheres without cross-linking agents. Thiolated chitosan microspheres seem to be more stable in aqueous media with respect to unmodified chitosan. The degradability by lysozyme appears quite similar for both polymers, showing that chemical modification does not influence the biodegradable properties of chitosan. Microspheres were able to control the drug release for at least 1 h, exhibiting comparatively strong mucoadhesive properties. The chitosan-TBA conjugate microparticles remain on the mucosa in a 2.5-fold higher concentration with respect to unmodified chitosan microparticles. These data suggest that chitosan-TBA conjugate microspheres have the potential to be used as a mucoadhesive drug delivery system.     

Application of Lipid Blend-Based Nanoparticulate Scaffold for Oral Delivery of Antihypertensive Drug: Implication on Process Variables and In Vivo Absorption Assessment

Purpose

The aim of the present study was to formulate and optimize lipid blend-based olmesartan medoxomil (OLM) loaded nanoparticulate scaffolds (NLCs) for enhanced oral bioavailability.

Method

The OLM-NLCs were formulated using dependent variables in different concentrations of solid lipid, liquid lipid, surfactant, and co-surfactant by using melt emulsification combined with ultrasonication technique. The formulations were experimentally optimized using a three-factor, three-level statistical design approach. The formulated OLM-NLCs were evaluated for various pharmaceutical quality evaluation parameters and further optimized formulation (OLM-NLCopt) was assessed for release kinetics, thermal behavior, and in vivo absorption assessment.

Result

The optimized formulation (OLM-NLCopt) showed particle size (138.7 nm), PDI (0.18), and entrapment efficiency (83.65%). The comparative in vitro release study revealed OLM-NLCopt showed significantly higher (p?<?0.05) drug release compare to OLM-susp. The in vivo study showed the OLM-NLCopt indicated nearly 3-fold improvement in oral bioavailability vis-a-vis OLM-susp in mice model.

Conclusion

The results of the release study and pharmacokinetic study suggest the potential of OLM-NLCs for improved oral delivery.

     

Beneficial effect of the leaves of Murraya koenigii (Linn.) Spreng (Rutaceae) on diabetes-induced renal damage in vivo

Ethnopharmacological relevance

Murraya koenigii (Linn.) Spreng (curry leaf) is widely used as a nephroprotective agent in kidney's infirmities among diabetics by the traditional practitioners in Malaysia. However, the latter role of curry leaf has been grossly under reported and is yet to receive proper scientific evaluation.

Aim of the study

The present study was designed to investigate the beneficial effect of the leaves of Murraya koenigii (Linn.) on diabetes-induced renal damage in vivo with regard to prove its efficacy by local traditional practitioners in the treatment of kidney frailties in diabetics.

Materials and methods

Aqueous (AQ) extract of the leaves of Murraya koenigii (Linn.) was administered to both normal and streptozotocin (STZ) induced diabetic male rats (Sprague-Dawley strain). Animals were divided into six groups (n = 6) and treated with variable dose levels of AQ extract (200 and 400 mg/kg body weight/day) for 30 days. At the end of 30 days, animals were sacrificed, blood was collected, processed and stored at −70 °C for the zestimation of serum urea and creatinine, changes in plasma antioxidant capacity by FRAP assay, and glutathione peroxidase levels, in the normal and STZ-induced diabetic rats. Histological changes of the kidneys of these animals were also evaluated by light microscopy to determine the beneficial effect of the leaves.

Results

Daily oral administration of variable dose levels of the AQ extract for 30 days, produced significant dose dependant decrease in serum urea and creatinine levels (p < 0.001), and marked increase in the levels of plasma antioxidant capacity (p < 0.01) in diabetic treated rats, compared to the control (non-diabetic) subjects. However, the normal treated rats showed minimal variation in these parameters in comparison to normal controls. Histological studies of the kidneys of these animals showed comparable tissue regeneration by the AQ extract.

Conclusion

The results of our study scientifically support the traditional belief for using the leaves of Murraya koenigii (Linn.) as adjuvant, in the treatment of pain disorders related to renal impairments among diabetics.     

Novel recombinant BCG expressing perfringolysin O and the over-expression of key immunodominant antigens; pre-clinical characterization,safety and protection against challenge with Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), has infected approximately two billion individuals worldwide with approximately 9.2 million new cases and 1.6 million deaths annually. Current efforts are focused on making better BCG priming vaccines designed to induce a comprehensive and balanced immunity followed by booster(s) targeting a specific set of relevant antigens in common with the BCG prime. We describe the generation and immunological characterization of recombinant BCG strains with properties associated with lysis of the endosome compartment and over-expression of key Mtb antigens. The endosome lysis strain, a derivative of BCG SSI-1331 (BCG₁₃₃₁) expresses a mutant form of perfringolysin O (PfoA_G137Q), a cytolysin normally secreted by Clostridium perfringens. Integration of the PfoA_G137Q gene into the BCG genome was accomplished using an allelic exchange plasmid to replace ureC with pfoA_G137Q under the control of the Ag85B promoter. The resultant BCG construct, designated AERAS-401 (BCG₁₃₃₁ ΔureC::ΩpfoA_G137Q) secreted biologically active Pfo, was well tolerated with a good safety profile in immunocompromised SCID mice. A second rBCG strain, designated AFRO-1, was generated by incorporating an expression plasmid encoding three mycobacterial antigens, Ag85A, Ag85B and TB10.4, into AERAS-401. Compared to the parental BCG strain, vaccination of mice and guinea pigs with AFRO-1 resulted in enhanced immune responses. Mice vaccinated with AFRO-1 and challenged with the hypervirulent Mtb strain HN878 also survived longer than mice vaccinated with the parental BCG. Thus, we have generated improved rBCG vaccine candidates that address many of the shortcomings of the currently licensed BCG vaccine strains.