MicroRNA biomarkers of platelet function

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation (BHF), VASCage (Centre for Promoting Vascular Health in the Ageing Community) of the Austrian Research Promotion Agency FFG (COMET program - Competence Centers for Excellent Technologies)

Introduction

Antiplatelet therapy (APT) leads to reduced morbidity and mortality in patients with cardiovascular disease but some still have thrombotic events. Tailoring APT to platelet function is currently limited by a lack of suitable platelet function tests. It has been previously shown that different circulating microRNAs (miRNAs) are derived from platelets and their measurement could provide new markers of platelet reactivity.

Purpose

To compare the release of different platelet miRNAs in response to different platelet agonists.

Methods

Measurements of platelet function were performed by light transmission aggregometry (LTA) in participants of the 2015 follow-up of the Bruneck study (n=338), using the following agonists: arachidonic acid (1mM), adenosine diphosphate (5µM, 20µM), collagen (0.4 µg/ml, 4 µg/ml, 10µg/ml), TRAP-6 amide (25µM) and U46619 (10µM). LTA platelet releasates were then used for RT-qPCR measurements of five platelet-enriched miRNAs (miR-21, miR-126, miR-150, miR-197, miR-223). Platelet-poor plasma (PPP) served as negative control.

Results

Platelet activation led to aggregation and extracellular release of miRNAs, with aspirin users (n=155) showing significantly lower miRNA release than non-aspirin users (n=183). Agonist responsiveness differed among miRNAs, with miR-21 being hyperresponsive to arachidonic acid and miR-150 being hyperresponsive to adenosine diphosphate, whilst release of miR-126, miR-197 and miR-223 was strongest to collagen (10µg/ml). In non-aspirin users, inflammation markers such as granulocyte counts or C-reactive protein correlated positively with platelet-derived miRNAs measured in PPP, whilst they correlated negatively with platelet-derived miRNAs measured in releasates. These effects were absent in aspirin users.

Conclusions

MiRNAs released from activated platelets can be reliably detected in PPP and platelet releasates. Preferential release of miRNAs in response to specific agonists suggests a selective release mechanism. Elevated PPP levels and decreased releasate levels of platelet-derived miRNAs in inflammatory environments suggest platelet exhaustion ex vivo due to platelet pre-activation.

Review: Induced pluripotent stem cell models of frontotemporal dementia

The increasing prevalence of dementia in the ageing population combined with the lack of treatments and the burden on national health care systems globally make dementia a public health priority. Despite the plethora of important research findings published over the past two decades, the mechanisms underlying dementia are still poorly understood and the progress in pharmacological interventions is limited. Recent advances in cellular reprogramming and genome engineering technologies offer an unprecedented new paradigm in disease modeling. Induced pluripotent stem cells (iPSCs) have enabled the study of patient-derived neurons in vitro, a significant progress in the field of dementia research. The first studies using iPSCs to model dementia have recently emerged, holding promise for elucidating disease pathogenic mechanisms and accelerating drug discovery. In this review, we summarize the major findings of iPSC-based studies in frontotemporal dementia (FTD) and FTD overlapping with amyotrophic lateral sclerosis (FTD/ALS). We also discuss some of the main challenges in the use of iPSCs to model complex, late-onset neurodegenerative diseases such as dementias.

A phase II clinical and biological study of lithium carbonate (Li) in patients with low-grade neuroendocrine tumors

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Background: Low-grade neuroendocrine tumors (NETs), such as carcinoid, islet cell tumors, and medullary thyroid carcinomas, respond poorly to chemotherapy, and effective, less toxic therapies are needed. Glycogen Synthase Kinase (GSK)-3β, a multifunctional protein kinase, has been shown to regulate growth and hormone production in NETs. Use of lithium carbonate (Li) in murine models suppressed carcinoid cell growth, reduced GSK-3β levels and reduced expression of chromogranin A. This study assessed the efficacy of Li in patients with NETs. Methods: Eligible pts had pathologically-proven, measurable low-grade NETs. Prior treatment was allowed if completed >4wks prior to registration. Standard eligibility criteria were used, and use of medications affecting Li metabolism or levels were prohibited. A single-arm, open-label, two-stage Phase II design was used. Li was dosed at 300mg orally TID with meals, titrated to a target serum level of 0.8–1.0mmol/L. The primary endpoint was objective tumor response by RECIST. Secondary endpoints included overall survival, progression-free survival, decrease of serum tumor markers, toxicity, and quality of life. Results: 15 pts were enrolled between 10/3/07and 7/17/08; 6 men, 9 women. The median age was 58 (range 47–74). Patients’ diagnoses were carcinoid tumor for 8 subjects, islet cell tumor for 5 subjects, and 2 unknown primary sites. ECOG PS was 0 (6 patients) or 1 (9 patients). Two pts came off study due to side effects (tremor, dizziness/abdominal pain). There were no radiographic responses. Due to an early stopping rule requiring at least 1 objective response in the first 13 evaluable pts, the study was closed to further accrual. 13 patients had pre- and post-therapy biopsies. Evaluation of quality of life and GSK-3β levels in tumor tissue is ongoing. Conclusions: Li was ineffective at obtaining a radiographic response in our 13 evaluable patients who were treated as part of this study. We will determine from tumor biopsies whether Li was effective at phosphorylating GSK-3β in order to make conclusions about GSK-3β as a therapeutic target for future NET treatment strategies. Funded through NIH grant R21CA117117- 01A2 and CTRC grant 1ULRR025011.

No significant financial relationships to disclose.

Catecholaminergic neurons in medullary nuclei are among the post-synaptic targets of descending projections from infralimbic area 25 of the rat medial prefrontal cortex

The infralimbic (IL) 'visceromotor' area of the rat medial prefrontal cortex projects to strategic subcortical nuclei involved in autonomic functions. Central among these targets are the nucleus tractus solitarius (NTS) and the rostral ventrolateral medulla (rVLM). By combining tract-tracing using the anterograde tracer biotinylated dextran amine (BDA) with immunolabeling for tyrosine hydroxylase (TH; an enzyme marker of catecholaminergic neurons), a limited proportion of BDA-labeled IL axonal boutons in the NTS and rVLM was found to be closely associated with TH immunopositive (+) target structures. Such structural appositions were mainly located proximally over the labeled dendritic arbors of identified TH+ neurons. Quantitative ultrastructural examination revealed that in NTS, TH+ dendritic shafts comprised 7.0% of the overall post-synaptic target population innervated by BDA-labeled IL boutons, whereas TH+ dendritic spines represented 1.25% of targets. In rVLM, TH+ shafts represented 9.0% and TH+ spines 2.5% of IL targets. Labeled IL boutons established exclusively asymmetric Gray Type 1 (presumed excitatory) synaptic junctions. The results indicate that subpopulations of catecholaminergic neurons in the NTS and rVLM are among the spectrum of post-synaptic neurons monosynaptically innervated by descending 'excitatory' input from IL cortex. Such connectivity, albeit restricted, identifies the potential direct influence of IL cortex on the processing and distribution of cardiovascular, respiratory and related autonomic information by catecholaminergic neurons in the NTS and VLM of the rat.

Clinical and immunological analysis of melanoma patients receiving immunization using particle-mediated gene transfer of genes for gp100 and GM-CSF into uninvolved skin

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Background: To investigate a new method of activating melanoma-specific immune responses, we examined in vivo particle-mediated gene transfer (PMGT) of cDNAs for gp100 and GM-CSF into uninvolved skin of melanoma patients (pts). We now report the analysis of a completed Phase I clinical study. Methods: Two treatment groups of 6 pts each were evaluated. Group I received PMGT with cDNA for gp100 during each 3 week cycle; Group II received PMGT with cDNA for GM-CSF followed 3 days later by PMGT for gp100 at the same site. PMGT used 0.25 ug DNA and 250 ug gold/treatment. Endpoints included vaccine toxicity, transgene expression, immunological activation, and antitumor effects. Results: No systemic toxicity could be attributed to the vaccines, while local toxicity in both groups included mild erythema and induration which resolved within 2 weeks. Monitoring for autoimmunity showed no induction of pathologic autoantibodies. Biopsies of vaccine sites obtained 2 days after the gp100 PMGT showed 16% of gold beads to be in the dermis in Group I vs 3% in Group II, suggesting the prior GM-CSF PMGT inhibited bead penetration (p < 0.001 by chi-square; each bead penetration was analyzed as an independent event). Biopsies in Group I obtained 2 days after vaccination showed 16% of beads in the dermis vs 22% after 4 days (p < 0.001 by chi-square; each bead penetration was analyzed as an independent event). Transgene expression in vaccinated skin sites was detected by ELISA (GM-CSF) and IHC (gp100). One of 4 HLA-A2+ subjects showed a 5 × 5-mm DTH response to gp100 peptide 210M after Cycle 1. Preliminary in vitro studies suggest minimal immunological activation. Of 4 pts who enrolled with no evidence of disease, 2 remain disease-free after 61–73 months of follow-up. Conclusions: PMGT with cDNA for gp100 and GM-CSF yields transgene expression in normal human skin with minimal local or systemic toxicity. Pathologic autoimmunity was not demonstrated. Bead concentration in the dermis increases over time, suggesting persistence of beads in this skin level. Conclusions related to melanoma-specific immune induction await T-cell and antibody studies. Supported in part by the UW General Clinical Research Center (M01 RR03186).

No significant financial relationships to disclose.

The effect of NCX4016 [2-acetoxy-benzoate 2-(2-nitroxymethyl)-phenyl ester] on the consequences of ischemia and reperfusion in the streptozotocin diabetic rat

The aim of this study was to assess the effect of chronic administration of NCX4016 [2 acetoxy-benzoate 2-(2-nitroxymethyl)-phenyl ester], a nitric oxide-releasing aspirin derivative on the consequences of coronary artery occlusion in streptozotocin-diabetic rats. Rats were made diabetic by injection of streptozotocin (60 mg kg(-1)) and received insulin (2.5 U kg(-1) s.c.) daily for 4 weeks. Animals received vehicle (1 ml kg(-1) polyethylene glycol), aspirin (65.2 mg kg(-1)), NCX4016 (60 mg kg(-1)), or (iv) NCX4016 (120 mg kg(-1)) orally, once daily for the last 5 days before coronary artery occlusion (CAO). One hour after the last dose, pentobarbital-anesthetized rats were subjected to CAO for 30 min followed by 120-min reperfusion. Neither drug significantly modified initial hemodynamics or plasma glucose levels compared with vehicle treatment in either nondiabetic or diabetic rats. Neither drug modified the total ventricular premature beat (VPB) count in normal animals, although NCX4016, but not aspirin, reduced the total VPB count and the incidence of ventricular tachycardia in diabetic rats. In nondiabetic animals, both aspirin and NCX4016 reduced infarct size. However, in diabetic rats, infarct size was reduced only by the larger dose of NCX4016 (120 mg kg(-1)) but not by aspirin or the lower dose of NCX4016. These results demonstrate that the cardioprotective effects of NCX4016 are reduced in the presence of diabetes compared with the effects seen in nondiabetic animals. In summary, the present study confirms the protective effect of NCX4016 against ischemia-reperfusion injury in the normal rat heart and demonstrates for the first time its protective effect in the heart of streptozotocin-diabetic rats.

Immunization by particle-mediated transfer of the granulocyte-macrophage colony-stimulating factor gene into autologous tumor cells in melanoma or sarcoma patients: report of a phase I/IB study

The primary objective of this phase I study was to determine the safety of an autologous tumor vaccine given by intradermal injection of lethally irradiated granulocyte-macrophage colony-stimulating factor (GM-CSF) gene-transfected autologous melanoma and sarcoma cells. Secondary objectives included validation of the gene delivery technology (particle-mediated gene transfer), determining the host immune response to the tumor after vaccination, and monitoring patients for evidence of antitumor response. Sixteen patients were treated with either of two different doses of GM-CSF-treated tumor cells. One patient received treatment with both doses of tumor cells. No treatment-related local or systemic toxicity was noted in any patient. Patients administered 100% treated cells (i.e., with a preparation of tumor cells that had all been exposed to GM-CSF DNA transfection) had a more extensive lymphocytic infiltrate at the vaccine site than did patients given 10% treated cells (a preparation of tumor cells in which 10% had been exposed to GM-CSF transfection) or nontreated tumor. The generation of a systemic immune response to autologous tumor by a delayed-type hypersensitivity response to the intradermal placement of nontransfected tumor cells was noted in one patient. One patient had a transient partial response of metastatic tumor sites. The entire procedure, from tumor removal to vaccine placement, was accomplished in less than 6 hr in all patients. Four of 17 patient tumor preparations produced greater than 3.0 ng of GM-CSF per 10(6) cells per 24 hr in vitro. The one patient with greater than 30 ng of GM-CSF per 10(6) cells per 24 hr in vitro had positive DTH, a significant histologic inflammatory response, and clinically stable disease. This technique of gene transfer was safe and feasible, but resulted in clinically relevant levels of gene expression in only a minority of patients.

Service-based survey of dystonia in munich

We performed a service-based epidemiological study of dystonia in Munich, Germany. Due to favourable referral and treatment patterns in the Munich area, we could provide confident data from dystonia patients seeking botulinum toxin treatment. A total of 230 patients were ascertained, of whom 188 had primary dystonia. Point prevalence ratios were estimated to be 10.1 (95% confidence interval 8.4-11.9) per 100,000 for focal and 0.3 (0.0-0.6) for generalised primary dystonia. The most common focal primary dystonias were cervical dystonia with 5.4 (4.2-6.7) and essential blepharospasm with 3.1 (2.1-4.1) per 100,000 followed by laryngeal dystonia (spasmodic dysphonia) with 1.0 (0.4-1.5) per 100,000.

What are the determinants of quality of life in people with cervical dystonia?

BACKGROUND

Little is known about the quality of life in patients with cervical dystonia, although pain and depression are relatively common.

OBJECTIVE

To test the hypothesis that an individual's ability to cope with the disease will modify the association of intrinsic, extrinsic, and disease related factors with quality of life.

METHODS

Patients with cervical dystonia diagnosed by a movement disorder specialist were recruited from seven European countries. Data on quality of life (SF-36), measures of coping, and intrinsic, extrinsic, and disease related factors were collected by a self completed postal questionnaire.

RESULTS

289 patients (101 men and 188 women), mean age 55 years, completed the questionnaire. Both physical and mental quality of life scores were predicted by self esteem and self deprecation, educational level, employment status, social support, response to botulinum toxin, disease severity, social participation, stigma, acceptance of illness, anxiety, and depression. In multivariable analyses, the strongest predictors were anxiety and depression. Severe depression was associated with a 19.1 point decrement in the physical summary score (95% confidence interval, -31.7 to -6.6; p = 0.003); however, disease duration and severity remained predictors.

CONCLUSIONS

Care for patients with cervical dystonia must not only focus on reducing the severity of the dystonia but also on the psychological wellbeing of the patient. Interventions aimed at treating depression or anxiety, especially of a cognitive nature, may have a large impact on improving quality of life.

Total chemical synthesis of human activin beta(A)[12-116] and related large-loop polypeptides

We report here the synthesis, purification, and characterization of several large polypeptides related to the human activin beta(A) subunit and their cyclic counterparts. In particular, we describe for the first time the total chemical synthesis of a 105-mer polypeptide, des[1-11] activin beta(A), and related large-loop polypeptide, by an optimized solid phase synthetic protocol based on 9-flouroenylmethyoxycarbonyl (Fmoc) chemistry. These studies show that automated chemical synthesis utilizing Fmoc-based solid phase synthetic strategies provides a practical alternative to recombinant DNA technology for the production of activin-related subunits, with the opportunity to rapidly provide different analogues and structural variants for subsequent structure-function and associated biophysical investigations.

Evaluation of poly-L-lactic acid and polyglycolic acid resorbable stents for repair of tracheomalacia in a porcine model

Poly-L-lactic acid and polyglycolic acid (PLPG) resorbable stents may offer a potential solution to the problem of tracheomalacia. Advantages of this material include its strength, its versatile shaping characteristics, and its resorbability, which would preclude surgical removal and allow for airway growth. The purpose of this pilot study was to examine the usefulness of PLPG stents for temporary external airway stenting of tracheomalacia in a porcine model. A severe tracheomalacia was created in 6 pigs by submucosal resection of segments of tracheal cartilage from 6 consecutive rings. The PLPG stent was then shaped to recreate the tracheal contour and sutured to the underlying airway. Endoscopic photodocumentation during spontaneous ventilation was obtained before and after reconstruction. After creation of the malacic tracheal segment, all animals developed stridor, retractions, and cyanosis during spontaneous ventilation. After repair, all animals were extubated without complication. All animals survived the follow-up period of 9 to 12 weeks without evidence of respiratory distress and with rapid weight gain. Repeat bronchoscopy showed no evidence of airway collapse during spontaneous ventilation. Tracheal measurements revealed growth of the stented segment with a mild narrowing within the repaired region. Histologic examination showed preservation of respiratory epithelium. These preliminary findings suggest that PLPG stents may serve a useful role in the surgical management of tracheomalacia.

Silver syndrome is not linked to any of the previously established autosomal dominant hereditary spastic paraplegia loci

The hereditary spastic paraplegias are a clinically variable and genetically heterogeneous group of disorders characterized by progressive and lower limb spasticity and weakness. Silver syndrome (SS) is a particularly disabling autosomal dominant form of the disease in which there is associated wasting of the hand muscles. In view of the fact that genes for hereditary spastic paraplegia can produce highly variable phenotypes, the eight known autosomal dominant loci were investigated for linkage to Silver syndrome. Genotyping of these loci in two large multigenerational families was incompatible with linkage to any of these regions, suggesting that an additional locus is responsible for this syndrome.

Oroesophageal candidiasis is lethal for transgenic mice with combined natural killer and T-cell defects

Germfree transgenic epsilon 26 (Tgepsilon26) mice, which express the full-length human CD3epsilon gene, have combined defects in natural killer (NK) cells and T cells were found to be extremely susceptible to oroesophageal (palate, tongue, esophagus) and gastric (cardia-antrum section) candidiasis. The gnotobiotic Tgepsilon26 mice die, apparently from severe oroesophageal candidiasis, within 2-4 weeks after their alimentary tracts are colonized with Candida albicans. The Tgepsilon26 mice manifest resistance to acute systemic candidiasis (intravenous injection) and to systemic candidiasis of endogenous origin for the first 2 weeks after their alimentary tracts are colonized with C. albicans. Granulocyte depletion data suggest that granulocytes, in the absence of functional NK cells and T cells, can protect Tgepsilon26 mice from acute systemic candidiasis and from systemic candidiasis of endogenous origin, for at least 14 days after alimentary tract colonization. Granulocytes and macrophages, in the absence of NK cells and T cells, are unable to protect Tgepsilon26 mice from lethal oroesophageal candidiasis and systemic candidiasis of endogenous origin which was evident in moribund Tgepsilon26 mice 2-4 weeks after colonization. Thus, non-T cells (i.e., NK cells) and T cells play important roles in resistance to oroesophageal and systemic (acute and of endogenous origin) candidiasis.

Determination of mouse bladder inflammatory response to E. coli lipopolysaccharide

Evaluation of the severity of histologic changes associated with cystitis is often subjective and inconsistent from one sample to the next. The objective of this study was to establish a consistent, reproducible method to quantify histologic changes in a mouse model of lipopolysaccharide (LPS)-induced cystitis. Either LPS (n = 8) or pyrogen-free saline (n = 8) was instilled intravesically into the bladders of female C57bk-6 J mice. Twenty-four hours later, mice in these groups as well as eight untreated controls were sacrificed and bladders were removed, fixed in formalin, and stained with hematoxylin and eosin (H&E). A bladder inflammatory index (BII) was described by reviewing tissues for edema, leukocyte infiltration, and hemorrhage. Cross-sections were evaluated by a single pathologist in a blinded manner based on the objective BII described. The BII method for objectively analyzing bladder inflammation was effective and reproducible. Bladders instilled with LPS had significantly increased inflammation scores for edema, leukocyte infiltration, and hemorrhage compared with those instilled with saline or untreated controls (n = 8, P < 0.05). These results demonstrate that LPS causes bladder inflammation when instilled intravesically and that inflammation of mouse bladders can be objectively quantified using the histological method described.

Probiotic effects of feeding heat-killed Lactobacillus acidophilus and Lactobacillus casei to Candida albicans-colonized immunodeficient mice

Probiotic bacteria can protect immunodeficient mice from orogastric candidiasis but cause some pathology of their own. Severely immunodeficient patients may be at risk if fed viable probiotics, so this study evaluated the probiotic potential of nonviable probiotic bacteria to protect immunodeficient mice from Candida albicans infections. Heat-killed probiotic bacteria were fed to gnotobiotic bg/bg-nu/nu and bg/bg-nu/+ mice to ascertain if they could protect the mice from mucosal and systemic candidiasis. Both heat-killed Lactobacillus acidophilus (HKLA) and heat-killed Lactobacillus casei (HKLC), in comparison to control mice not fed the probiotic bacteria but challenged (oral) with C. albicans, suppressed the severity of orogastric candidiasis in bg/bg-nu/nu mice at 2 weeks after colonization with C. albicans, inhibited disseminated candidiasis in C. albicans-colonized bg/bg-nu/+ mice at 4 weeks after colonization, and suppressed the number of viable C. albicans in the alimentary tract. HKLA, but not HKLC, treatment inhibited disseminated candidiasis in bg/bg-nu/nu mice at 2 weeks after oral challenge and enhanced the proliferative responses of splenocytes from C. albicans-colonized bg/bg-nu/+ mice to C. albicans antigens. Neither HKLA nor HKLC were able to prolong the survival of gnotobiotic bg/bg-nu/nu mice after oral challenge with C. albicans. These results demonstrate that heat-killed lactobacilli can induce some (limited) protection (probiotic effect) against candidiasis in mice.

Disparate requirement for T cells in resistance to mucosal and acute systemic candidiasis

Although highly susceptible to orogastric candidiasis, T-cell receptor delta- and alpha-chain knockout mice, deficient in gammadelta and alphabeta T cells, respectively, were found to be resistant to disseminated candidiasis of endogenous origin and to acute systemic candidiasis (resulting from intravenous injection).

MR-guided angioplasty of renal artery stenosis in a pig model: a feasibility study

PURPOSE

To test the hypothesis that magnetic resonance (MR) imaging can guide the percutaneous treatment of renal artery stenosis in a pig model.

MATERIALS AND METHODS

Ameroid constrictors were surgically placed around six renal arteries in four pigs. After 30-36 days, all stenoses were documented by conventional x-ray aortograms. MR-guided renal angioplasty was attempted for three stenoses. For these pigs, MR angiography was performed with use of contrast-enhanced three-dimensional (3D) techniques. The authors visualized catheters by filling them with dilute 4% gadolinium and imaging with two-dimensional (2D) and 3D MR fast spoiled gradient recalled echo techniques. Under MR guidance, the authors advanced a selective catheter into the affected renal artery and crossed the stenosis with a nitinol guide wire. Angioplasty was performed with a balloon catheter filled with dilute gadolinium. Stenosis and luminal diameter measurements were compared before and after angioplasty.

RESULTS

After ameroid constrictor placement, four significant stenoses, one mild stenosis, and one occlusion developed. Under MR guidance, the authors achieved technical success in performing three of three (100%) attempted dilations. After MR-guided angioplasty, the mean reduction in stenosis was 35% and the mean increase in luminal diameter was 1.6 mm.

CONCLUSION

Use of MR guidance for the angioplasty of renal artery stenosis in pigs is feasible.

Interpreting the clinical significance of the differential inhibition of cyclooxygenase-1 and cyclooxygenase-2

The International Consensus Meeting on the Mode of Action of COX-2 Inhibition (ICMMAC) brought together 17 international experts in arthritis, gastroenterology and pharmacology on 5 6 December 1997. The meeting was convened to provide a definition of COX-2 specificity and to consider the clinical relevance of COX-2-specific agents. These compounds are a new class of drugs that specifically inhibit the enzyme COX-2 while having no effect on COX-1 across the whole therapeutic dose range. The objectives of the meeting were to review the currently available data regarding the roles and biology of COX-1 and COX-2, and to foster a consensus definition on COX-2 specificity. At the present time, no guidelines exist for the in vitro and in vivo assessment of COX specificity, and it was felt that consensus discussion might clarify some of these issues. The meeting also reviewed recent clinical data on COX-2-specific inhibitors. The following article reflects discussion at this meeting and provides a consensus definition of COX-2-specific inhibitors.

Mucosal and systemic candidiasis in IL-8Rh-/- BALB/c mice

Germ-free BALB/c mice, genetically engineered to be deficient for interleukin-8 (IL-8) receptor homolog (IL-8Rh-/-), were more susceptible to gastric candidiasis after oral challenge and to acute systemic candidiasis after intravenous challenge than IL-8Rh+/+ controls. In comparison to IL-8Rh+/+ mice, the IL-8Rh-/- mice had slower influx of polymorphonuclear neutrophils (PMN) into Candida albicans-infected tissues and a lower percentage of PMN in peritoneal exudate cells (PEC) elicited with heat-killed C. albicans. PEC from IL-8Rh-/- mice exhibited less luminol-dependent chemiluminescence in response to C. albicans and did not kill C. albicans hyphae as well as PEC from IL-8Rh+/+ mice. C. albicans-colonized IL-8Rh-/- mice showed no histological evidence of systemic candidiasis. These results suggest a role for the IL-8Rh in murine resistance to gastric and acute systemic candidiasis, but not in resistance to systemic candidiasis of endogenous origin.

Purification of CMP-N-acetylneuraminic acid synthetase from bovine anterior pituitary glands

CMP-beta-N-acetylneuraminic acid (CMP-neuNAc) is the substrate for the sialylation of glycoconjugates by sialyltransferases in microbes and higher eukaryotes. CMP-neuNAc synthetase catalyzes the formation of this substrate, CMP-neuNAc, from CTP and neuNAc. In this report we describe the purification of CMP-neuNAc synthetase from bovine anterior pituitary glands. The enzyme was purified by ion exchange, gel filtration, and affinity chromatography. The protein was homogeneous on SDS-PAGE with a molecular weight of 52 kDa, a subunit size similar to that of the E.coli K1 (48.6 kDa). The identity of the 52 kDa protein band was confirmed by native gel electrophoresis in that the position of the enzyme activity in gel slices coincided with the position of major bands in the stained gel. Photoaffinity labeling with 125I-ASA-CDP ethanolamine resulted in the modification of a 52 kDa polypeptide that was partially protected against modification by the substrate CTP. Enzyme activity in crude fractions could be adsorbed onto an immunoadsorbent prepared from antibody against the purified 52 kDa protein. Taken together these data suggest that the 52 kDa polypeptide purified by this procedure described in this report is indeed CMP-neuNAc synthetase. The active enzyme chromatographed on a gel filtration column at 158 kDa suggesting it exists in its native form as an oligomer.

Targeted gene disruption reveals an adhesin indispensable for pathogenicity of Blastomyces dermatitidis

Systemic fungal infections are becoming more common and difficult to treat, yet the pathogenesis of these infectious diseases remains poorly understood. In many cases, pathogenicity can be attributed to the ability of the fungi to adhere to target tissues, but the lack of tractable genetic systems has limited progress in understanding and interfering with the offending fungal products. In Blastomyces dermatitidis, the agent of blastomycosis, a respiratory and disseminated mycosis of people and animals worldwide, expression of the putative adhesin encoded by the WI-1 gene was investigated as a possible virulence factor. DNA-mediated gene transfer was used to disrupt the WI-1 locus by allelic replacement, resulting in impaired binding and entry of yeasts into macrophages, loss of adherence to lung tissue, and abolishment of virulence in mice; each of these properties was fully restored after reconstitution of WI-1 by means of gene transfer. These findings establish the pivotal role of WI-1 in adherence and virulence of B. dermatitidis yeasts. To our knowledge, they offer the first example of a genetically proven virulence determinant among systemic dimorphic fungi, and underscore the value of reverse genetics for studies of pathogenesis in these organisms.

Interleukin-12 gene transfer results in CD8-dependent regression of murine CT26 liver tumors

BACKGROUND

Interleukin (IL)-12 has potent antitumor effects in animal models. We hypothesized that direct transfer of the IL-12 gene to established tumors would result in tumor regression without significant toxicity.

METHODS

Liver tumors were established by direct injection of CT26, a murine adenocarcinoma, into the livers of BALB/c mice, followed by three transfections with either murine IL-12, murine granulocyte-macrophage colony-stimulating factor, or luciferase cDNA using particle-mediated gene transfer. To assess the mechanism of this effect, immunohistochemical staining and depletion experiments with anti-CD4 or -CD8 antibodies were performed.

RESULTS

Progressive growth of primary tumors and carcinomatosis were present by day 16 after transfection with luciferase or murine granulocyte-macrophage colony-stimulating factor. At 50 days, complete regression of tumor was evident in seven of eight IL-12-treated mice (P < .001). In IL-12-transfected livers, immunohistochemical staining revealed an increase in CD8+ T cells. Selective depletion of CD4+ or CD8+ T cells was performed before and during transfection with murine IL-12. At 50 days, 75% of control mice were tumor-free. Only 46% of CD4+ cell-depleted mice (P = .143) and 7% of CD8+ cell-depleted mice (P < .001) were tumor-free.

CONCLUSIONS

IL-12 gene transfer using particle-mediated gene transfer results in complete regression of established CT26 liver tumors in 88% of mice; this effect is dependent on CD8+ T cells.

Early resistance of interleukin-10 knockout mice to acute systemic candidiasis

In contrast to immunocompetent controls, interleukin-10 (IL-10) knockout (KO) mice eliminated an experimental intravenous inoculation with Candida albicans from their kidneys. Improved clearance of C. albicans from the kidneys of IL-10 KO mice was evident at 24 h after intravenous challenge with the fungus. Conversely, mice with a deletion of the IL-4 cytokine gene were more susceptible to systemic candidiasis than were immunocompetent controls. The hyperresistance of IL-10 KO mice to acute systemic candidiasis did not seem to correlate with nitric oxide-mediated immunity, but rather, it appeared to be associated with more efficient effector function of innate cells, possibly neutrophils. In support of the latter hypothesis, we observed that neutrophils from IL-10 KO mice were more efficient at killing C. albicans blastoconidia and hyphae than were neutrophils from immunocompetent control mice. Neither IL-10 KO nor IL-4 KO mice that were monoassociated with C. albicans for 4 weeks showed any histologic evidence of systemic candidiasis of endogenous origin. In contrast to systemic candidiasis, we observed no significant (P < 0.05) differences in susceptibility among IL-10 KO, IL-4 KO, and wild-type (immunocompetent) mice to orogastric candidiasis. Our results suggest that IL-10 exerts a negative effect on the early, innate response to acute systemic candidiasis; however, in comparison to immunocompetent control (wild-type) mice, neither IL-10 nor IL-4 deficiency enhanced susceptibility to orogastric candidiasis.

The revised Anxious Thoughts and Tendencies (AT&T) scale: a general measure of anxiety-prone cognitive style

BACKGROUND

The AT&T was developed from a perspective which proposes that panic disorder with agoraphobia arises from interaction between a specific biological predisposition, expressed in spontaneous panic attacks, and a general anxiety-prone cognitive style. Many items of the original AT&T, a putative measure of the cognitive component, were complex and ambiguous; and normative data were not available.

METHOD

In this research, the items were simplified and clarified. A community sample of northern New Mexico Hispanics and geographically matched non-Hispanic whites was identified from an earlier epidemiological study. The sample included 151 Anglos and 168 Hispanics; 98 respondents aged 18-34, 75 aged 35-49, 69 aged 50-64, and 77 aged 65 or more; and 111 men and 208 women.

RESULTS

Factor analysis produced one major factor with high loadings from the 15 negatively worded items, that accounted for about 41% of the total variation in the 15 items. The mean major factor score for Anglos was 1.65 with a standard deviation of 0.48, and for Hispanics was 1.76+/-0.52. F = 4.17, df = 1/311, P < 0.05, and effect size d = 0.22. There were no significant age or gender effects. Item analysis of the major factor produced item/total correlations from 0.49 to 0.68 and a Cronbach's alpha of 0.91. In a separate clinical sample of 30 patients with panic disorder, the test-retest correlation of the major factor at baseline and after 8 weeks of treatment was 0.75. In the community sample, the correlations of the major factor with anxiety-related clusters of the SCL-90 were: Somatization, 0.36; Anxiety, 0.53: and Phobia, 0.44.

CONCLUSIONS AND RECOMMENDATIONS

We recommend that the AT&T be reduced to the 15 items of its major factor, and we supply quantiles and moments based on the full community sample of 319 as a standard of comparison. Further research with the AT&T in clinical samples of patients with anxiety disorders is ongoing.

Variable biotherapeutic effects of Lactobacillus acidophilus isolates on orogastric and systemic candidiasis in immunodeficient mice

Two commercially available isolates of Lactobacillus acidophilus (NCFM and LA-1) were compared for their capacities to protect immunodeficient bg/bg-nu/un and bg/bg-nu/+ mice from candidiasis. L. acidophilus NCFM prolonged survival of adult and neonatal bg/bg-nu/nu mice, inhibited disseminated candidiasis in both mouse strains, suppressed weight loss associated with Candida albicans infection in bg/bg-nu/nu females, but did not decrease the severity or the incidente of orogastric candidiasis in gnotobiotic mice. L. acidophilus LA-1 suppressed numbers of C. albicans in the alimentary tracts of bg/bg-nu/+ mice and reduced the severity of mucosal candidiasis in bg/bg-nu/nuand bg/bg-nu/+ mice; however, L. acidophilus LA-1 did not improve the survival of bg/bg-nu/nu mice after oral challenge (colonization) with C. albicansand it was associated with lethality in gnotobiotic adult female bg/bg-nu/nu mice. These results demonstrate that the two isolates of L. acidophilus differed in their capacity to protect immunodeficient mice from candidiasis.

Biotherapeutic effects of Bifidobacterium spp. on orogastric and systemic candidiasis in immunodeficient mice

Two commercially available Bifidobacterium spp. (Bifidobacterium infantis and Bifidobacterium lactis) were compared for their capacities to protect immunodeficient bg/bg-nu/nuand bg/bg-nu/+mice from orogastric and lethal candidiasis. Both Bifidobacterium spp. prolonged the survival of Candida albicans-colonized adult and neonatal bg/bg-nu/numice. The bifidobacteria affected the production of antibodies to C. albicans, inhibited disseminated candidiasis, suppressed weight loss associated with C. albicans infection, inhibited the growth of C. albicans in the alimentary tract, inhibited systemic candidiasis of endogenous origin, and decreased the severity of gastric candidiasis in both mouse strains. B. infantis inhibited systemic candidiasis of endogenous origin better than B. lactis; however, B. lactis was significantly more effective at inhibiting C. albicans colonization of the alimentary tract, suppressing gastric candidiasis, and protecting bg/bg-nu/numice from lethal candidiasis than B. infantis. These results show that Bifidobacterium spp. can protect immunodeficient mice from candidiasis but different species manifest quantitative and qualitative differences in their probiotic and biotherapeutic effects.

The genetics of Parkinson's disease and parkinsonian syndromes

The finding of a mutation in the alpha-synuclein gene in a rare autosomal dominant form of idiopathic Parkinson's disease (IPD), has prompted increased interest in identifying genes that account for the more common sporadic form. A number of association studies have suggested that functional polymorphisms in genes that play a role in dopamine, drug and toxin metabolism may increase the relative risk of IPD. Unfortunately, patient numbers are often small, and the results have not been consistently reproduced. This article reviews the evidence from epidemiological, imaging and genetic studies to determine the role of genetic susceptibility in IPD and parkinsonian syndromes.

Candidiasis in interferon-gamma knockout (IFN-gamma-/-) mice

Germ-free C57BL/6 x 129 interferon-gamma knockout (IFN-gamma(-/-)) mice and their immunocompetent (+/-, +/+) counterparts were colonized with a pure culture of Candida albicans to assess their natural susceptibility to mucosal and systemic candidiasis of endogenous origin. Colonization with a pure culture of C. albicans was not lethal for adult or neonatal IFN-gamma(-/-) gnotobiotic mice over the 15-week study. The IFN-gamma(-/-) mice were more susceptible to gastric (cardia-antrum section), anorectal, and acute systemic (intravenous challenge) candidiasis than immunocompetent controls, and some IFN-gamma(-/-) mice developed intestinal adenomas after colonization with C. albicans. The enhanced susceptibility of IFN-gamma(-/-) mice, compared with immunocompetent controls, may be associated with a poor proliferative response of spleen cells to C. albicans antigens and a T helper 2 (IgG1) serum antibody response to C. albicans antigens. Thus, IFN-gamma is important for murine resistance to gastric, anorectal, and acute systemic candidiasis.

Laparoscopic cryosurgery of the kidney in the porcine model: an acute histological study

OBJECTIVES

To verify histologically whether cryosurgery of the kidney can be accomplished reproducibly without injuring adjacent structures, using a combination of ultrasound and laparoscopic guidance.

MATERIALS AND METHODS

Six kidneys from three domestic female farm pigs were utilized in the study. Under general anesthesia and after obtaining pneumoperitoneum, the lower pole of the kidney was mobilized laparoscopically and the ureter and adjacent bowel were protected with saline-soaked gauze. Two 3.8 mm-cryoprobes were placed percutaneously into the lower pole and cryoablation was carried out under laparoscopic and ultrasound guidance using a double-freeze technique (10-minute freeze and 5-minute thaw cycles to a probe temperature of -185 degrees C to -196 degrees C) in five kidneys (one control). The kidneys, adjacent ureter and bowel were harvested acutely, and macroscopic, histologic, and electron microscopic evaluation of all specimens was performed.

RESULTS

Macroscopically, clear margins of cryodestruction corresponded with the ultrasound images of the iceball. In all five treated kidneys, reproducible cell death corresponding to visible margins of cryodestruction were verified histologically. Cell death was further corroborated by electron microscopy. Adjacent structures (ureter and bowel) were sectioned and no significant damage was noted. Blood pressure remained constant throughout the procedure. A crack in the renal parenchyma of one kidney was noted during the thaw phase; at harvest that animal was found to have an intraperitoneal hemorrhage.

CONCLUSION

Combined laparoscopic and ultrasound-guided cryoablation of the lower pole of the kidney can be accomplished reproducibly in the porcine model without injury to adjacent structures.