Analyzing immune response to engineered hydrogels by hierarchical clustering of inflammatory cell subsets

Understanding the immune response to hydrogel implantation is critical for the design of immunomodulatory biomaterials. To study the progression of inflammation around poly(ethylene glycol) hydrogels presenting Arg-Gly-Asp (RGD) peptides and vascular endothelial growth factor, we used temporal analysis of high-dimensional flow cytometry data paired with intravital imaging, immunohistochemistry, and multiplexed proteomic profiling. RGD-presenting hydrogels created a reparative microenvironment promoting CD206+ cellular infiltration and revascularization in wounded dorsal skin tissue. Unbiased clustering algorithms (SPADE) revealed significant phenotypic transition shifts as a function of the cell-adhesion hydrogel properties. SPADE identified an intermediate macrophage subset functionally regulating in vivo cytokine secretion that was preferentially recruited for RGD-presenting hydrogels, whereas dendritic cell subsets were preferentially recruited to RDG-presenting hydrogels. Last, RGD-presenting hydrogels controlled macrophage functional cytokine secretion to direct polarization and vascularization. Our studies show that unbiased clustering of single-cell data provides unbiased insights into the underlying immune response to engineered materials.

Dual delivery of IL-10 and AT-RvD1 from PEG hydrogels polarize immune cells towards pro-regenerative phenotypes

Inflammation after traumatic injury or surgical intervention is both a protective tissue response leading to regeneration and a potential cause of wound complications. One potentially successful strategy to harness to pro-regenerative roles of host inflammation is the localized delivery of bioactive materials to induce immune suppressive cellular responses by cells responding to injury. In this study, we designed a fully synthetic poly (ethylene) glycol (PEG)-based hydrogel to release the specialized pro-resolving lipid mediator aspirin-triggered resolvin-D1 (AT-RvD1) and recombinant human interleukin 10 (IL-10). We utilized a unique side-by-side internally controlled implant design wherein bioactive hydrogels were implanted adjacent to control hydrogels devoid of immune modulatory factors in the dorsal skinfold window chamber. We also explored single-immune cell data with unsupervised approaches such as SPADE. First, we show that RGD-presenting hydrogel delivery results in enhanced immune cell recruitment to the site of injury. We then use intra-vital imaging to assess cellular recruitment and microvascular remodeling to show an increase in the caliber and density of local microvessels. Finally, we show that the recruitment and re-education of mononuclear phagocytes by combined delivery IL-10 and AT-RvD1 localizes immune suppressive subsets to the hydrogel, including CD206+ macrophages (M2a/c) and IL-10 expressing dendritic cells in the context of chronic inflammation following surgical tissue disruption. These data demonstrate the potential of combined delivery on the recruitment of regenerative cell subsets involved in wound healing complications.

Combination bupropion SR and varenicline for smoking cessation: a systematic review

BACKGROUND

Tobacco is the leading cause of preventable death in the world. Current cessation medications include nicotine replacement therapy (NRT), varenicline, and bupropion, while combination therapy primarily entails NRT with either varenicline or bupropion. However, recent studies have examined varenicline and bupropion in combination.

OBJECTIVES

A systematic review assessing the efficacy and safety of combination varenicline and bupropion was conducted.

METHODS

PubMed and Clinicaltrials.gov were searched using terms: "varenicline combination", "bupropion combination", "bupropion AND varenicline", and "bupropion AND varenicline combination smoking cessation", yielding four studies including 1193 total patients.

RESULTS

Combination therapy yielded greater efficacy than varenicline monotherapy in two randomized controlled trials and one retrospective outcomes study. One single-arm Phase II trial provided additional efficacy and safety data. Of the prospective trials, one displayed a greater 4-week smoking abstinence for weeks 8-11 with combination (39.8%) versus monotherapy (25.9%) (OR = 1.89; 95% CI = 1.07-3.35). The other demonstrated greater prolonged abstinence (continuous abstinence from week 2) at 12 weeks (OR = 1.49; 95% CI = 1.05-2.12) and 26 weeks (OR = 1.52; 95% CI = 1.04-2.22), though results were not significant at 52 weeks in this study. The retrospective study displayed higher success rates (continuous abstinence rates at 52 weeks) with combination varenicline and bupropion (55.0%; compared to varenicline monotherapy (32.1%), p < 0.001). Subgroup analyses suggest that this combination may be more beneficial in males and patients with higher baseline nicotine dependence.

CONCLUSION

To the authors' knowledge, this is the first review conducted to compile current literature on this novel pharmacotherapy combination for smoking cessation. Combination bupropion SR and varenicline displayed greater efficacy in smoking cessation than varenicline monotherapy, though further safety analysis is warranted to rule out additive psychiatric adverse effects.

Akt inhibition upregulates FasL, downregulates c-FLIPs and induces caspase-8-dependent cell death in Jurkat T lymphocytes

In T lymphocytes, the role of Akt in regulating Fas/Fas ligand (FasL)-mediated apoptotic signaling and death is not clearly understood. In this study, we observed that inhibition of Akt causes enhanced expression of FasL mRNA and protein and increased death-inducing signaling complex (DISC) formation with Fas-associated death domain (FADD) and procaspase-8 recruitment. Also, caspase-8 was activated at the DISC with accompanying decrease in c-FLIPs expression. FasL neutralizing antibody significantly decreased apoptotic death in the Akt-inhibited T cells. Additionally, Akt inhibition-induced Fas signaling was observed to link to the mitochondrial pathway via Bid cleavage. Further, inhibition of caspase-8 activity effectively blocked the loss of mitochondrial membrane potential and DNA fragmentation, suggesting that DISC formation and subsequent caspase-8 activation are critical initiating events in Akt inhibition-induced apoptotic death in T lymphocytes. These data demonstrate yet another important survival function governed by Akt kinase in T lymphocytes, which involves the regulation of FasL expression and consequent apoptotic signaling.

Hex-1, a gene unique to filamentous fungi, encodes the major protein of the Woronin body and functions as a plug for septal pores

We have identified a gene, named hex-1, that encodes the major protein in the hexagonal crystals, or Woronin bodies, of Neurospora crassa. Analysis of a strain with a null mutation in the hex-1 gene showed that the septal pores in this organism were not plugged when hyphae were damaged, leading to extensive loss of cytoplasm. When grown on agar plates containing sorbose, the hex-1(-) strain showed extensive lysis of hyphal tips. The HEX-1 protein was predicted to be 19,125 Da. Analysis of the N-terminus of the purified protein indicated that 16 residues are cleaved, yielding a protein of 17,377 Da. A polyclonal antibody raised to the HEX-1 protein recognized multiple forms of the protein, apparently dimers and tetramers that were resistant to solubilization by sodium dodecyl sulfate and reducing reagents. Treatment of the protein with phosphatase caused dissociation of these oligomers. Preparations enriched in Woronin bodies contained catalase activity, which was not detected in comparable fractions from the hex-1(-) mutant strain. These results support the hypothesis that the Woronin body is a specialized peroxisome that functions as a plug for septal pores.

Myotonic dystrophy in transgenic mice expressing an expanded CUG repeat

Myotonic dystrophy (DM), the most common form of muscular dystrophy in adult humans, results from expansion of a CTG repeat in the 3' untranslated region of the DMPK gene. The mutant DMPK messenger RNA (mRNA) contains an expanded CUG repeat and is retained in the nucleus. We have expressed an untranslated CUG repeat in an unrelated mRNA in transgenic mice. Mice that expressed expanded CUG repeats developed myotonia and myopathy, whereas mice expressing a nonexpanded repeat did not. Thus, transcripts with expanded CUG repeats are sufficient to generate a DM phenotype. This result supports a role for RNA gain of function in disease pathogenesis.

Pilot study of growth hormone administration during the refeeding of malnourished anorexia nervosa patients

OBJECTIVE

In anorexia nervosa (AN), medical stabilization and nutritional repletion are pivotal steps toward physical and psychological recovery. Nutritional stabilization is often difficult in this patient group. Recombinant human growth hormone (rhGH) has been safely used as adjuvant therapy in other groups of malnourished patients. We hypothesize that rhGH treatment will hasten medical stabilization in AN patients.

STUDY DESIGN

Fifteen patients admitted for inpatient treatment for AN, ages 12-18 years, were enrolled in a 28-day randomized, double-blind, placebo-controlled study. Patients received rhGH (0.05 mg/kg subcutaneously) or an equivalent volume of placebo daily. Outcome measures included time to reach medical/cardiovascular stability, rate of weight gain, and duration of hospitalization. All patients received a standard refeeding protocol.

RESULTS

Mean admission body mass index was 14.5 kg/m2. The rhGH and placebo groups did not differ significantly in admission weight, BMI or daily caloric intake. Patients treated with rhGH reached medical/cardiovascular stability more rapidly than those treated with placebo (median 17 vs. 37 days, p = 0.02). Numerical but not statistically significant improvements were seen in weight gain and length of hospitalization in the rhGH group.

CONCLUSION

Patients treated with rhGH achieved medical/cardiovascular stability more rapidly than those treated with placebo, and this, in turn, decreased the length of stay.

Review article: potential gastrointestinal effects of long-term acid suppression with proton pump inhibitors

This review examines the evidence for the development of adverse effects due to prolonged gastric acid suppression with proton pump inhibitors. Potential areas of concern regarding long-term proton pump inhibitor use have included: carcinoid formation; development of gastric adenocarcinoma (especially in patients with Helicobacter pylori infection); bacterial overgrowth; enteric infections; and malabsorption of fat, minerals, and vitamins. Prolonged proton pump inhibitor use may lead to enterochromaffin-like cell hyperplasia, but has not been demonstrated to increase the risk of carcinoid formation. Long-term proton pump inhibitor treatment has not been documented to hasten the development or the progression of atrophic gastritis to intestinal metaplasia and gastric cancer, although long-term studies are required to allow definitive conclusions. At present, we do not recommend that patients be tested routinely for H. pylori infection when using proton pump inhibitors for prolonged periods. Gastric bacterial overgrowth does increase with acid suppression, but important clinical sequelae, such a higher rate of gastric adenocarcinoma, have not been seen. The risk of enteric infection may increase with acid suppression, although this does not seem to be a common clinical problem with prolonged proton pump inhibitor use. The absorption of fats and minerals does not appear to be significantly impaired with chronic acid suppression. However, vitamin B12 concentration may be decreased when gastric acid is markedly suppressed for prolonged periods (e.g. Zolllinger-Ellison syndrome), and vitamin B12 levels should probably be assessed in patients taking high-dose proton pump inhibitors for many years. Thus, current evidence suggests that prolonged gastric acid suppression with proton pump inhibitors rarely, if ever, produces adverse events. Nevertheless, continued follow-up of patients taking proton pump inhibitors for extended periods will provide greater experience regarding the potential gastrointestinal adverse effects of long-term acid suppression.

Increased monocyte nuclear factor-kappaB activation and tumor necrosis factor production in alcoholic hepatitis

Increased tumor necrosis factor-a activity has been reported in patients with alcoholic hepatitis and is implicated in its pathogenesis. The aim of this study was to investigate potential mechanisms of increased tumor necrosis factor-a activity in alcoholic hepatitis. Monocyte nuclear factor-kB activity was assessed by electrophoretic mobility shift assay, monocyte tumor necrosis factor-a mRNA was semi-quantitatively assessed by reverse transcriptase polymerase chain reaction, and tumor necrosis factor-a in monocyte culture supernatants was measured. There was significantly greater spontaneous nuclear factor-kB activity in the monocytes of 6 patients with alcoholic hepatitis as compared with that in the monocytes of control subjects. There was spontaneous tumor necrosis factor-a mRNA and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis but not from the monocytes of normal subjects. Endotoxin increased nuclear factor-kB activity and induced tumor necrosis factor-a mRNA and tumor necrosis factor-a release from normal subjects' monocytes. Endotoxin further increased nuclear factor-kB activity, tumor necrosis factor-a mRNA, and tumor necrosis factor-a release from the monocytes of patients with alcoholic hepatitis. Supershift assays indicate that the monocyte nuclear factor-kB activation involves the p50 and p65 subunits. Dysregulated tumor necrosis factor-a metabolism in alcoholic hepatitis monocytes is associated with increased nuclear factor-kB activity and tumor necrosis factor-a mRNA expression.

Complementary and alternative medicine and gastrointestinal diseases

Complementary and alternative medicine (CAM) is becoming increasingly utilized as a form of health care, with recent studies suggesting that over 40% of Americans use some form of CAM. This has major financial implications for the health care industry. Traditional physicians frequently are unaware of CAM use by their patients, and there are potential interactions between CAM and traditional forms of medical therapy. Many of the medicinal CAM agents have been used for their postulated anti-inflammatory and/or antifibrotic effects. CAM is especially frequently used in patients with chronic diseases. This review discusses CAM use in three types of chronic gastrointestinal diseases--liver disease, irritable bowel syndrome and dyspepsia, and inflammatory bowel disease.

Concurrent validity of the Bayley Scales of Infant Development II Motor Scale and the Peabody Developmental Motor Scales in two-year-old children

Concurrent validity of the Bayley Scales of Infant Development, Second Edition (BSID II) Motor Scale and the Peabody Developmental Motor Scales (PDMS) was examined by administering both tests to 38 two-year-old Native American children. A correlation analysis of age equivalent scores indicated very good to high correlation for the BSID II Motor Scale with the PDMS Fine Motor Scale (PDFMS) (r = .87) and the PDMS Gross Motor Scale (PDGMS) (r = .83). A correlation analysis of standard scores showed poor to unacceptable correlation between the BSID II Motor Scale with the PDFMS (r = .64) and the PDGMS (r = .49); further, there was poor agreement between the classifications of significantly delayed, mildly delayed, and within normal limits performance on each test. The PDFMS tended to classify children lower than the BSID II Motor Scale. The scores of the relatively younger children within each of the PDMS 6-month age categories agreed less between the tests than did the scores of the relatively older children. In conclusion, this study provides evidence for the concurrent validity of the BSID II Motor Scale and the PDMS for age equivalent scores, but not for standard scores of 2-year-old children. Professionals must be aware of the strengths and limitations of the BSID II and the PDMS, and choose appropriately to avoid denial of or over-referral for services for young children.

Motor development of Native American children on the Peabody Developmental Motor Scales

OBJECTIVE

Native American children have not been widely represented in the normative samples of standardized tests assessing motor development. This study investigated the cultural relevance of the Peabody Developmental Motor Scales (PDMS) in 2-year-old Native American children who are typically developing.

METHOD

The PDMS was administered to a sample of 44 Pueblo children who were 24 months through 35 months of age and typically developing. Each child's family also completed a parent questionnaire addressing the child's development and family demographics. Participant scores were compared with those of the normative sample.

RESULTS

The sample scored significantly lower than the normative sample (p < or = .001) on the Fine Motor Scale, and, when gender was taken into consideration, all but the older girls (30 months-35 months of age) had significantly lower scores. All but the younger girls (24 months-29 months of age) scored within the normal range on the Gross Motor Scale.

CONCLUSION

Our results with this small sample suggest that caution be used when comparing motor performance (especially fine motor abilities) of 2-year-old Native American children against the PDMS normative data.

Evaluation of the feasibility and use of a prototype remote drug delivery capsule (RDDC) for non-invasive regional drug absorption studies in the GI tract of man and beagle dog

PURPOSE

Evaluate a prototype Remote Drug Delivery Capsule (RDDC) for use in beagle dogs and human volunteers for non-invasive drug absorption studies in different regions of the gastrointestinal tract.

METHODS

The device was dual radiolabeled and GI transit of the RDDC was monitored by gamma scintigraphy. Beagles were used initially to demonstrate the functional utility of the device where a solution of ranitidine hydrochloride (150 mg) was non-invasively delivered to the stomach, proximal small intestine and distal small intestine. A subsequent first time in human study enrolled twelve healthy male volunteers where the intended site of release was the stomach, early small bowel, distal small bowel or colon.

RESULTS

Preliminary studies conducted in beagles indicated that the RDDC operated successfully and the onset of ranitidine serum levels were dependent on the time of capsule activation and site of drug release. Results from the human study showed that all twelve subjects swallowed the device with no discomfort. Mean gastric emptying of the RDDC was 1.50 +/- 1.28 h (range = 0.25 to 4.25 h), and total small intestine transit was 4.79 +/- 1.82 h (range = 2.00 to 8.25 h). The capsule was retrieved from the feces at 30.25 +/- 15.21 h (range = 14.12 to 74.25 h) and there were no reported adverse events. The prototype RDDC operated successfully in nine of the twelve human volunteers and the cause for the three failures was attributed to mechanical failure while the electronics assembly performed favorably.

CONCLUSIONS

This prototype remote control capsule was shown to be well tolerated and functional to use in human volunteers as well as beagles. The application of the device coupled with gamma scintigraphy has the potential to be a valuable and rapid method to non-invasively evaluate regional drug absorption in the gastrointestinal tract under conditions that are both pharmaceutically and physiologically meaningful.

The heart of the matter: care conferences to promote parent-professional collaboration

Children who are hospitalized frequently or who have lengthy admissions often require a large number of caregivers to meet their complex health care needs. Even the most organized of teams may experience confusion in their attempt to stay abreast of each other's care of the child. This can be particularly confusing to parents who are trying to cope with the stress of hospitalization, learning to navigate new financial and social service systems, attempting to remember the names and faces of the numerous specialists and their specific recommendations, and caring for their child. The University of New Mexico Children's Hospital in Albuquerque, New Mexico has developed and used a care conference model that includes families, medical staff, social workers, nutritionists, child life specialists, and specialized therapy provides in the process of integrating developmentally appropriate practices within the scope of necessary medical care.

Expansion of the myotonic dystrophy CTG repeat reduces expression of the flanking DMAHP gene

Myotonic dystrophy, or dystrophia myotonica (DM), is a highly variable multisystem disease in which the classic adult-onset form displays progressive muscle wasting, cataracts, heart block, gonadal atrophy, insulin resistance and neuropsychiatric impairment. Its genetic basis is an expansion of CTG trinucleotide repeats in the DMPK protein kinase gene. Among the triplet repeat expansion disorders, DM is distinguished by the extended length of the repeat tract (5-13 kb in postmortem tissue) and its location in the 3' untranslated region of the gene that contains it. The pathophysiological mechanism for multisystem degeneration in DM is not understood. In contrast to the profound muscle wasting that characterizes advanced DM, only minor histopathological abnormalities have occurred in DMPK knockout mice or in mice that overexpress a human DMPK transgene, making it unlikely that changes in DMPK activity provide a unitary explanation for the disease. A DNAse hypersensitive site that maps 0.7 kb downstream (centromeric) from the CTG repeats is eliminated on DM chromosomes. This finding indicates that the repeat expansion may alter the adjacent chromatin structure and raises the possibility that it may also affect the expression of flanking genes. An interesting candidate flanking gene is DMAHP, a recently discovered homeodomain-encoding gene. We show here that DMAHP expression in myoblasts, muscle and myocardium is reduced by the DM mutation is cis, and the magnitude of this effect depends on the extent of CTG repeat expansion. These observations support the hypothesis that DMAHP participates in the pathophysiology of DM.

The use of upper extremity anthropometrics in the clinical assessment of patients with amyotrophic lateral sclerosis

We evaluated the feasibility of using upper extremity anthropometrics to monitor the clinical status of 18 patients with amyotrophic lateral sclerosis (ALS). The bone-free arm muscle area (AMA) was computed using measurement of triceps skinfold thickness and the mid-upper arm circumference according to published formulae. The AMA correlated significantly with body mass, isokinetic muscle force generation, cross-sectional muscle area on computerized tomography scanning, and pulmonary functions including forced vital capacity and maximal voluntary ventilation. Serial determinations of AMA demonstrated a decline in 10 of 13 patients over 6 months. We pilot tested the use of AMA in a clinical trial of ciliary neurotrophic factor (CNTF) in the treatment of ALS. The AMA progressively decreased by 13%, 15%, and 30% in ALS patients treated with 0 microg CNTF/kg, 15 microg CNTF/kg, and 30/microg CNTF/kg, respectively, over a 9-month treatment period. We conclude that measurement of AMA provides a simple, inexpensive method to monitor the progression of muscle atrophy in ALS patients. The technique does not require effort on the part of the patient and as such, appears to have potential utility as an outcome measure in clinical drug trials.

Kupffer cell depletion by gadolinium chloride enhances liver regeneration after partial hepatectomy in rats

Although previous work suggests that tumor necrosis factor-alpha (TNF) promotes liver regeneration after partial hepatectomy (PH), the source of TNF is unknown. If Kupffer cells release TNF after PH, then Kupffer cell depletion by gadolinium chloride (GdCl) should inhibit liver regeneration. To test this hypothesis, cytokine expression and regenerative events were compared in GdCl-treated and control rats. Functional assays and Northern blot analysis of a Kupffer cell-specific mRNA confirmed that GdCl depleted Kupffer cells. Despite this, semiquantitative reverse transcription-polymerase chain reaction analysis of total hepatic RNA showed six- to eightfold higher levels of TNF transcripts in GdCl-treated rats. In this group, PH caused 12-to 16-fold greater induction of interleukin-6, a TNF-inducible cytokine, and two- to threefold greater induction of several cytokine-regulated genes (c-jun, C/EBP-beta, and C/EBP-delta). GdCl also amplified regeneration-associated increases in the DNA binding activity of AP-1, a growth regulatory transcription factor. Furthermore, hepatic incorporation of [3H]thymidine, expression of the S-phase antigen, proliferating cell nuclear antigen, and the hepatocyte mitotic index were each significantly greater in GdCl-treated rats. Thus, although GdCl causes Kupffer cell depletion, it does not decrease liver TNF and actually enhances liver regeneration after PH.