Exercise mitigates calpain induced Purkinje cell loss in diabetes.

Calpain-1 is a ubiquitous calcium dependent cysteine protease and found in cytoplasm as well as mitochondria. We have earlier reported that active calpain-1 is translocated from cytosol to mitochondria and activates MMP9. Calpain-1 activation is detrimental to the heart in several different ways, but there is little evidence that it can degrade Purkinje cell protein (PCP-4) and impair contractility in diabetes. Our hypothesis is that in diabetes, PCP-4 is degraded by calpain-1, causing contractile dysfunction that can be mitigated by exercise. To test this hypothesis, we recruited four groups of mice, 1) db/+ control, 2) db/+ with exercise, 3) db/db, 4) db/db with exercise. The mice were exercised on treadmill for 8 weeks as per American Veterinary Research Guidelines. Adding calcium to isolated cardiomyocytes caused them to lose shape and die. Compared with live myocytes, we observed high calpain-1 levels as well as significantly lower levels of PCP-4 and increased levels of calmodulin and calmodulin kinase II (CaMKII) in dead myocytes. We used the CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats) plasmid to knock down calpain-1 in HL-1 myocytes which restored the levels of PCP-4 along with calmodulin and CaMKII. In vivo, we found upregulated levels of calpain-1 in db/db mice (diabetic) as compared to db/+ which were mitigated in the exercised mice. Conclusively our data strongly suggests that in diabetes there is high induction of calpain-1 with degrades PCP-4, a protein important for contractility and exercise can mitigate this.

Bilateral Ultrasound-guided Erector Spinae Plane Block for Postoperative Analgesia in Lumbar Spine Surgery: A Randomized Control Trial.

BACKGROUND: Major lumbar spine surgery causes severe postoperative pain. The primary objective of this randomized controlled study was to compare the effect of ultrasound (US)-guided erector spinae plane (ESP) block on 24-hour postoperative cumulative opioid requirements with standard (opioid-based) analgesia. Postoperative pain control and patient satisfaction were also assessed. MATERIALS AND METHODS: Adults scheduled for elective lumbar spine surgery under general anesthesia were randomly assigned to the following (and they are): Control group-no preoperative ESP block, or ESP block group-preoperative bilateral US-guided ESP block. Both groups received standard general anesthesia during surgery. Postoperative pain score, number of patients requiring rescue analgesia, and total morphine consumption during the first 24 postoperative hours were recorded. Patient satisfaction was assessed 24 hours after surgery. RESULTS: Postoperative morphine consumption was significantly lower in patients in the ESP group compared with those in the control group (1.4±1.5 vs. 7.2±2.0 mg, respectively; P<0.001). All patients in the control group required supplemental morphine compared with only 9 (45%) in the ESP block group (P=0.002). Pain scores immediately after surgery (P=0.002) and at 6 hours after surgery (P=0.040) were lower in the ESP block group compared with the control group. Patient satisfaction scores were more favorable in the block group (P<0.0001). CONCLUSIONS: US-guided ESP block reduces postoperative opioid requirement and improves patient satisfaction compared with standard analgesia in lumbar spine surgery patients.

PLGA nanoparticles for ocular delivery of loteprednol etabonate: a corneal penetration study.

The purpose of the present study was to develop loteprednol etabonate (LE) loaded poly(d,l-lactide co-glycolide) (PLGA) nanoparticles (NPs) and study their penetration profile into the excised goat cornea. In the present study, LE loaded PLGA NPs were prepared by solvent evaporation with high speed homogenization method and the penetration profile was studied using confocal laser scanning microscopy (CLSM). Rhodamine (Rd) was used as a fluorescent marker to prepare Rd-LE-PLGA-NPs. The NPs were characterized for particle size, X-ray diffraction (XRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), drug entrapment, and permeation profile. Intense fluorescence observed across the depths of goat corneal tissue suggested an improved penetration profile of NPs. The entrapment efficiency and mean diameter of the optimized formulation (F5) were found to be 96.31 ± 1.68% and 167.6 ± 0.37 nm, respectively. These findings indicate that LE loaded PLGA NPs may serve as a potential drug carrier for ocular administration in eye disease.

RNA Interference Using c-Myc-Conjugated Nanoparticles Suppresses Breast and Colorectal Cancer Models.

In this article, we report the development and preclinical validation of combinatorial therapy for treatment of cancers using RNA interference (RNAi). RNAi technology is an attractive approach to silence genes responsible for disease onset and progression. Currently, the critical challenge facing the clinical success of RNAi technology is in the difficulty of delivery of RNAi inducers, due to low transfection efficiency, difficulties of integration into host DNA and unstable expression. Using the macromolecule polyglycidal methacrylate (PGMA) as a platform to graft multiple polyethyleneimine (PEI) chains, we demonstrate effective delivery of small oligos (anti-miRs and mimics) and larger DNAs (encoding shRNAs) in a wide variety of cancer cell lines by successful silencing/activation of their respective target genes. Furthermore, the effectiveness of this therapy was validated for in vivo tumor suppression using two transgenic mouse models; first, tumor growth arrest and increased animal survival was seen in mice bearing Brca2/p53-mutant mammary tumors following daily intratumoral treatment with nanoparticles conjugated to c-Myc shRNA. Second, oral delivery of the conjugate to an Apc-deficient crypt progenitor colon cancer model increased animal survival and returned intestinal tissue to a non-wnt-deregulated state. This study demonstrates, through careful design of nonviral nanoparticles and appropriate selection of therapeutic gene targets, that RNAi technology can be made an affordable and amenable therapy for cancer.

Penetration of tamoxifen citrate loaded ethosomes and liposomes across human skin: a comparative study with confocal laser scanning microscopy.

In the present study, ethosomal and liposomal formulations containing tamoxifen citrate were prepared and evaluated for their penetration properties in human cadaver skin using Franz diffusion cell and confocal laser scanning microscope (CLSM). The results clearly revealed that ethosomal vesicles showed a better drug permeation profile than that of liposomal vesicles. In addition, low fluorescence intensity in CLSM was recorded with liposomes as compared to ethosomes, indicating lower cumulative amount of drug permeation from liposomal vesicles. Furthermore, CLSM showed uniform fluorescence intensity across the entire depth of skin in ethosomal treatment, indicating high penetrability of ethosomal vesicles through human cadaver skin. In contrast, low penetrability of conventional liposomal vesicles was recorded as penetration was limited to the 7(th) section (i.e. upper epidermis layer) of skin as evident from visualization of intact liposomal vesicles in CLSM.