This issue of the Biomedical Journal welcomes articles from a wide range of disciplines. We take a look at the optimization of surgical techniques in rabbits and visit some of the medical wonders of stem cell technology. In particular, we highlight Sasmita Biswal's discussion of an emerging link between the use of proton pump inhibitors and hospital-acquired Clostridium difficile infections, in addition to intriguing data showing that environmental enrichment protects hippocampal neurons from damage in stressed, diabetic rats.

The purinergic receptor P2X ligand-gated ion channel 7 (P2X7) is ubiquitously expressed in almost all tissues and organs of the body with the highest distribution in the immune cells of monocyte-macrophage origin. Classically, P2X7 receptor is involved in apoptotic cell death, and it is well known that extracellular ATP ligation to this purinergic receptor serves as an important secondary stimulus, which is also considered as danger signal for the interleukin (IL)-1β cleavage and secretion from pro-inflammatory cells. More recently, however, there has been substantial evidence of additional roles for the P2X7 receptor, both in innate immune response and as an adaptive link, including T-cell activation in a chronic state of inflammation. Also, compelling evidences have revealed an important role for ectonucleotidases as ATP-consuming enzymes in the control and fine-tuning of P2X7 function by regulating the time, concentration, and availability of ATP during infection-driven inflammation. This review focuses on the current evidences for P2X7 receptor involvement in the initial stages of inflammation, as well as for its role in acute and chronic stages of infection. Here, we also highlight the role of ectonucleotidase family in the control of P2X7 function, including the initial and resolution phases of inflammation.

Increased incidence of Clostridium difficile infection (CDI) among in-patients is associated with significant increased mortality, morbidity, and stay in the hospitals. This has occurred despite heightened awareness of the risks of broad-spectrum antibiotics, overall reduction in antibiotic use and increased focus on hospital hygiene. So though the main risk factor for CDI is use of broad-spectrum antibiotics, the use of proton pump inhibitors (PPIs) as a novel potential contributor has been implicated, because of their ability to substantially reduce gastric acid secretion which is an important host defense mechanism in suppressing the ingested C. difficile or its spores. Antibiotic disruption of the normal intestinal flora and reduced gastric acidity have been suggested as the risk factors for C. difficile-associated diarrhea (CDAD). Based on such assumptions the use of PPIs may be associated with an increased risk of CDAD. While a definite association between PPI use and CDAD has not yet been confirmed, the possibility and such an association however cannot be ruled out at present. Thus among the identified risk factors, the use of PPI is important, previously unrecognized and modifiable risk factors whose use should be carefully evaluated among hospital in-patients receiving antibiotics, especially in those with a diagnosis of C. difficile diarrhea.

The surgery-first approach in orthognathic surgery has recently created a broader interest in completely eliminating time-consuming preoperative orthodontic treatment. Available evidence on the surgery-first approach should be appraised to support its use in orthognathic surgery. A MEDLINE search using the keywords "surgery first" and "orthognathic surgery" was conducted to select studies using the surgery-first approach. We also manually searched the reference list of the selected keywords to include articles not selected by the MEDLINE search. The search identified 18 articles related to the surgery-first approach. There was no randomized controlled clinical trial. Four papers were excluded as the content was only personal opinion or basic scientific research. Three studies were retrospective cohort studies in nature. The other 11 studies were case reports. For skeletal Class III surgical correction, the final long-term outcomes for maxillofacial and dental relationship were not significantly different between the surgery-first approach and the orthodontics-first approach in transverse (e.g., intercanine or intermolar width) dimension, vertical (e.g., anterior open bite, lower anterior facial height) dimension, and sagittal (e.g., anterior-posterior position of pogonion and lower incisors) dimension. Total treatment duration was substantially shorter in cases of surgery-first approach use. In conclusion, most published studies related to the surgery-first approach were mainly on orthognathic correction of skeletal Class III malocclusion. Both the surgery-first approach and orthodontics-first approach had similar long-term outcomes in dentofacial relationship. However, the surgery-first approach had shorter treatment time.

Background: Modification of human airway smooth muscle (ASM) function by proinflammatory cytokines has been regarded as a potential mechanism underlying bronchial hyperresponsiveness in asthma. Human ASM cells express intercellular adhesion molecule (ICAM)-1 in response to cytokines. Synthetic ligands for peroxisome proliferator-activated receptor (PPAR)γ reportedly possess anti-inflammatory and immunomodulatory properties. In this study, we examined whether ciglitazone, a synthetic PPARγ ligand, can modulate the basal and tumor necrosis factor (TNF)α-induced ICAM1 gene expression in human ASM cells. Methods: Human ASM cells were treated with TNFα. ICAM-1 expression was assessed by flow cytometry and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. PPARγ activity was inhibited by target-specific small interfering (si) RNA targeting PPARγ and GW9662, a PPARγ antagonist. Activity of nuclear factor (NF)-κB was assessed by using immunoblot analysis, immune-confocal images, and electrophoretic mobility shift assay (EMSA). Results: By flow cytometry, ciglitazone alone had no effect on ICAM-1 expression in ASM cells, but inhibited ICAM-1 expression in response to TNFα (10 ng/ml) in a dose-dependent manner (1-10 μM). It also inhibited TNFα-induced ICAM1 gene expression by RT-PCR analysis. Knockdown of PPARγ gene by target-specific siRNA targeting PPARγ enhanced ICAM-1 expression and the inhibitory effect of ciglitazone on TNFα-induced ICAM-1 expression was reversed by PPARγ siRNA and GW9662. SN-50 (10 μg/ml), an inhibitor for nuclear translocation of NF-κB, inhibited TNFα-induced ICAM-1 expression. Ciglitazone did not prevent TNFα-induced degradation of the cytosolic inhibitor of NF-κB (IκB), but inhibited the nuclear translocation of p65 induced by TNFα and suppressed the NF-κB/DNA binding activity. Conclusion: These findings suggest that ciglitazone inhibits TNFα-induced ICAM1 gene expression in human ASM cells through the ligand-dependent PPARγ activation and NF-κB-dependent pathway.

Background: Total knee arthroplasty (TKA) carries a substantial rate of venous thromboembolism (VTE). The blood-saving of effect of tranexamic acid (TEA) in TKA using enoxaparin for thromboprophylaxis has been well known. However, the routine use of chemoprophylaxis in TKA remains controversial because of postoperative bleeding complications. Therefore, the purpose of this study was to retrospectively compare the incidence of VTE, and postoperative blood loss and wound-related complications in minimally invasive (MIS)-TKA patients who received rivaroxaban or enoxaparin prophylaxis. Methods: A total of 113 patients who underwent primary unilateral MIS-TKA between 2009 and 2012 were studied. Of these, 61 patients (study group) received rivaroxaban prophylaxis between 2011 and 2012 and a control group of 52 patients received enoxaparin prophylaxis between 2009 and 2010. All patients received one intraoperative injection of TEA (10 mg/kg). We compared the changes in hemoglobin (Hb) level, postoperative drainage amount, total blood loss, transfusion rate, and incidence of postoperative wound complications and VTE between the two groups. Results: No differences in postoperative Hb levels, blood drainage amount, total blood loss, and transfusion rate were observed between the two groups. No deep-vein thrombosis of the leg or pulmonary embolism was noted in both groups. There were no major wound complications including hematoma and infection requiring surgical intervention for open irrigation or debridement. Conclusions: Our retrospective study demonstrated a low rate of VTE in MIS-TKA patients who received rivaroxaban or enoxaparin when TEA was used for bleeding prophylaxis. No increased perioperative bleeding or postoperative wound-related complications were observed in the rivaroxaban group compared with the enoxaparin group.

Background: Neuromuscular electric stimulation (NMES) induces repeated muscular contraction, possibly promoting the perfusion/oxygenation of the regional tissues. It remains unclear how NMES influences vascular hemodynamic property and segmental fluid distribution/composition in paretic extremities of hemiplegic patients. Methods: Eleven hemiplegic patients aged 62.6 ± 12.5 years in the subacute stage of stroke received NMES for paretic wrist extensor and flexor muscles 30 min daily, 5 days per week for 4 weeks. The non-paretic upper extremities (NPUE) that did not receive NMES served as control. Distribution of fluid to intra/extracellular milieu and arterial hemodynamic properties were determined by using the multi-frequency bioelectrical impedance and pulse wave analysis, respectively. Results: Compared with NPUE without NMES, paretic upper extremity (PUE) with NMES revealed a significantly less decrease in arterial blood flow, impedance quotient, slope quotient, and less increase in crest width and crest time of arterial pulse wave. NMES for 4 weeks increased body cell mass in PUE. Furthermore, NPUE without NMES reduced intracellular water, whereas PUE with NMES retarded loss of intracellular water after stroke. Conclusion: NMES therapy increases body cell mass, attenuates reduction of intracellular water, and alleviates arterial hemodynamic disturbance in PUE in subacute stroke. However, stroke-related physical deconditioning may negatively regulate body composition and impair hemodynamic function in NPUE.

Background: Platelets are routinely stored in plasma for 5 days at an average temperature of 22°C. In the present study, the shelf life of random donor platelets was extended by storing for 7 days with and without additive solution at temperatures of 22°C, 18°C, and 16°C. Methods: Random donor platelets were stored in 100% plasma and 20%/80% platelet additive solution. The data were compared using paired "t"- test. The confidence limit was kept at 95%, hence a "p" < 0.05 was considered to be statistically significant. Results: Out of total 150 samples, 148 samples were analyzed and 2 were discarded due to the bacterial contamination on day 7 at 22°C without platelet additive solution. A significant difference in platelet count, platelet factor 3 (PF 3), glucose, lactate dehydrogenase (LDH), and platelet aggregation was observed on day 7 (p < 0.001) at 16°C in without platelet additive solution. In platelet additive solution, the mean values of platelet count, platelet distribution width (PDW), LDH, and pH showed no significant difference on day 7 at 22°C, 18°C, and 16°C. Only significant differences were observed in the levels of mean platelet volume (MPV), PF 3, glucose, and platelet aggregation on day 7 (p < 0.001) at 16°C of the storage period. Conclusion: Random donor platelets functions are better maintained in platelet additive solution as compared to plasma at a lower temperature of 18°C but not at 16°C, on the 7 ^th day.

Background: Postlaminectomy dural adhesion is a common cause of recurrent symptoms. Hyaluronic acid-based gel has been reported to reduce the incidence of postoperative adhesion in the peritoneal cavity; however, its effect on preventing postoperative scar formation at laminectomy sites is not yet known. The purpose of this study was to evaluate the anti-adhesive effect of hyaluronic acid-based gelatin after laminectomy, using a rabbit model. Methods: Twelve adult New Zealand rabbits underwent two-level lumbar laminectomy, and were randomly assigned to one of two groups of six rabbits each. The treatment group received hyaluronic acid-based gelatin treatment and the control group was untreated. Rabbits were sacrificed 8 weeks after treatment. Peel-off testing and histological analysis were performed to assess the tenacity and the extent of adhesion formation. Results: No significant difference was observed in the neurologic performance between the two groups. The tenacity in the treatment group was significantly reduced compared to that of the control group (3.17 ± 0.75 vs. 4.33 ± 0.52, respectively; p = 0.016). Histological analysis showed significantly less scar tissue formation in the treatment group, with a larger subarachnoid space and greater distance between the dura and scar tissues. The amount of fibroblast cells also was significantly smaller in the treatment group than in the control group (3078 ± 313.68 vs. 3742 ± 455.65, respectively; p = 0.042). Conclusions: No serious adverse events were reported, and no difference was found in the incidence of complications between the treatment and control groups. The findings suggested that hyaluronic acid-based gelatin may be effective for preventing postlaminectomy dural adhesion in rabbits.

Background: Environmental enrichment (EE) exposure is known to influence the structural changes in the neuronal network of hippocampus. In the present study, we evaluated the effects of EE exposure on the streptozotocin (STZ)-induced diabetic and stressed rat hippocampus. Methods: Male albino rats of Wistar strain (4-5 weeks old) were grouped into normal control (NC), vehicle control (VC), diabetes (DI), diabetes + stress (DI + S), diabetes + EE (DI + E), and diabetes + stress + EE (DI + S + E) groups (n = 8 in each group). Rats were exposed to stress and EE after inducing diabetes with STZ (40 mg/kg). Rats were sacrificed on Day 30 and brain sections were processed for cresyl violet staining to quantify the number of surviving neurons in the CA1, CA3, and dentate hilus (DH) regions of hippocampus. Results: A significant (p < 0.001) decrease in the number of survived neurons was noticed in DI (CA1, 34.06 ± 3.2; CA3, 36.1 ± 3.62; DH, 9.83 ± 2.02) as well as DI + S (CA1, 14.03 ± 3.12; CA3, 20.27 ± 4.09; DH, 6.4 ± 1.21) group rats compared to NC rats (CA1, 53.64 ± 2.96; CA3, 62.1 ± 3.34; DH, 21.11 ± 1.03). A significant (p < 0.001) increase in the number of survived neurons was observed in DI + E (CA1, 42.3 ± 3.66; CA3, 46.73 ± 4.74; DH, 17.03 ± 2.19) and DI + S + E (CA1, 29.69 ± 4.47; CA3, 36.73 ± 3.89; DH, 12.23 ± 2.36) group rats compared to DI and DI + S groups, respectively. Conclusions: EE exposure significantly reduced the amount of neuronal damage caused by complications of diabetes and stress to the neurons of hippocampus.

Background: Prenatal magnetic resonance (MR) imaging demonstration of the normal spinal cord and the conus medullaris location has not been well studied. We compared balanced fast field echo (bFFE) with single-shot turbo spin-echo (SSh-TSE) MR sequences for visualizing the normal spinal cord and position of conus medullaris in fetuses. Methods: This retrospective study was approved by the Institutional Review Board of Chang Gung Medical Foundation. We reviewed the MR images of 141 fetuses aged between 16 and 39 gestational weeks, to determine the position of the conus and visualize the spinal cord by using a signal intensity ratio of cerebral spinal fluid (CSF) to the spinal cord. Results: Of the 75 subjects having normal spinal cord and being examined by both bFFE and SSh-TSE studies, the signal intensity ratio of CSF/cord was greater on bFFE images (2.18 ± 0.53) than that on SSh-TSE images (1.21 ± 0.13) (p < 0.05). The conus level identified in the 50 subjects, in whom the lumbosacral spine was appropriately imaged, was located from L1 to L5 levels. The ascendance of the conus correlated moderately with gestational age. Conclusions: With greater signal contrast ratio of CSF to spinal cord, bFFE sequence, when compared with SSh-TSE sequence, provides better visualization of normal spinal cord. The fetal conus medullaris ascends from L5 to L1 levels as the gestational age increases.

Stem cell therapy is emerging as a viable approach in regenerative medicine. A 31-year-old male with brachial plexus injury had complete sensory-motor loss since 16 years with right pseudo-meningocele at C5-D1 levels and extra-spinal extension up to C7-D1, with avulsion on magnetic resonance imaging and irreversible damage. We generated adipose tissue derived neuronal differentiated mesenchymal stem cells (N-AD-MSC) and bone marrow derived hematopoietic stem cells (HSC-BM). Neuronal stem cells expressed β-3 tubulin and glial fibrillary acid protein which was confirmed on immunofluorescence. On day 14, 2.8 ml stem cell inoculum was infused under local anesthesia in right brachial plexus sheath by brachial block technique under ultrasonography guidance with a 1.5-inch-long 23 gauge needle. Nucleated cell count was 2 × 10 ⁴ /μl, CD34+ was 0.06%, and CD45-/90+ and CD45-/73+ were 41.63% and 20.36%, respectively. No untoward effects were noted. He has sustained recovery with re-innervation over a follow-up of 4 years documented on electromyography-nerve conduction velocity study.