Gold-silver-alloy nanoprobes for one-pot multiplex DNA detection

A specific colorimetric DNA detection method based on oligonucleotide functionalized gold-silver-alloy nanoparticles (AuAg-alloy-nanoprobes) is presented. The AuAg-alloy-nanoprobes were then used for the specific detection of a DNA sequence from TP53-a gene involved in cancer development. The AuAg-alloy-nanoprobes were then used in combination with Au-nanoprobes for a one-pot dual-colour detection strategy that allowed for the simultaneous differential detection of two distinct target sequences. This system poses an unprecedented opportunity to explore the combined use of metal nanoparticles with different composition towards the development of a multiplex one-pot colorimetric assay for DNA detection.

Upper esophageal sphincter and gastroesophageal junction pressure changes act to prevent gastroesophageal and esophagopharyngeal reflux during apneic episodes in patients with obstructive sleep apnea

BACKGROUND

Gastroesophageal reflux (GER) is thought to be induced by decreasing intraesophageal pressure during obstructive sleep apnea (OSA). However, pressure changes in the upper esophageal sphincter (UES) and gastroesophageal junction (GEJ) pressure during OSA events have not been measured. The aim of this study was to determine UES and GEJ pressure change during OSA and characterize the GER and esophagopharyngeal reflux (EPR) events during sleep.

METHODS

We studied 15 controls, nine patients with GER disease (GERD) and without OSA, six patients with OSA and without GERD, and 11 patients with both OSA and GERD for 6 to 8 h postprandially during sleep. We concurrently recorded the following: (1) UES, GEJ, esophageal body (ESO), and gastric pressures by high-resolution manometry; (2) pharyngeal and esophageal reflux events by impedance and pH recordings; and (3) sleep stages and respiratory events using polysomnography. End-inspiration UES, GEJ, ESO, and gastric pressures over intervals of OSA were averaged in patients with OSA and compared with average values for randomly selected 10-s intervals during sleep in controls and patients with GERD.

RESULTS

ESO pressures decreased during OSA events. However, end-inspiratory UES and GEJ pressures progressively increased during OSA, and at the end of OSA events were significantly higher than at the beginning (P < .01). The prevalence of GER and EPR events during sleep in patients with OSA and GERD did not differ from those in controls, patients with GERD and without OSA, and patients with OSA and without GERD.

CONCLUSIONS

Despite a decrease in ESO pressure during OSA events, compensatory changes in UES and GEJ pressures prevent reflux.

Apoptosis and glutathione: beyond an antioxidant

Apoptosis is a conserved homeostatic process critical for organ and tissue morphogenesis, development, and senescence. This form of programmed cell death also participates in the etiology of several human diseases including cancer, neurodegenerative, and autoimmune disorders. Although the signaling pathways leading to the progression of apoptosis have been extensively characterized, recent studies highlight the regulatory role of changes in the intracellular milieu (permissive apoptotic environment) in the efficient activation of the cell death machinery. In particular, glutathione (GSH) depletion is a common feature of apoptotic cell death triggered by a wide variety of stimuli including activation of death receptors, stress, environmental agents, and cytotoxic drugs. Although initial studies suggested that GSH depletion was only a byproduct of oxidative stress generated during cell death, recent discoveries suggest that GSH depletion and post-translational modifications of proteins through glutathionylation are critical regulators of apoptosis. Here, we reformulate these emerging paradigms into our current understanding of cell death mechanisms.

Rapid reduction in hospitalisations after an intervention to manage severe asthma

Asthma is the third cause of hospitalisations due to clinical illnesses in Brazil. The Programme for Control of Asthma in Bahia (ProAR) leads an initiative in Salvador City (Brazil) to manage severe asthma for free. The aim of this study was to identify trends in asthma hospitalisation in the entire city and to evaluate the impact of ProAR. Information on asthma hospitalisations from 1998 to 2006 was collected. We analysed trends in Salvador (2.8 million inhabitants) before and after ProAR, taking pneumonia and myocardial infarction into account for local comparison. As an external control we obtained information on asthma from Recife, which is the most comparable Brazilian city. In Salvador, asthma hospital admissions declined by 82.3% (1998-2006). A greater proportion of this reduction (74%) occurred after 2003, in parallel with the implementation of ProAR. The reduction in asthma admissions in Recife was smaller. The rates of hospitalisation in 2006 were 2.25 per 10,000 inhabitants in Salvador and 17.06 in Recife. In Salvador, we found an inverse correlation between the provision of medication for asthma and hospitalisation (-0.801; p<0.0001). A rapid reduction in asthma admissions in the entire city of Salvador was associated with ProAR, a public health intervention targeting severe asthma.

Early detection by magnetic resonance imaging of fetal cerebral damage in a fetus with hydrops and cytomegalovirus infection

We discuss the use of magnetic resonance imaging (MRI) to reveal early fetal neurological involvement of cytomegalovirus (CMV) infection. A woman presented at 21 weeks of pregnancy with active CMV infection. Cerebral ultrasound examination had been normal. An MRI scan revealed a thickened germinal matrix, which was histologically confirmed, associated with underdevelopment of the gyri. Brain MRI proved particularly useful in identifying the findings not disclosed by routine ultrasound during pregnancy and subsequently confirmed at histology.

Terminating motor events for TLESR are influenced by the presence and distribution of refluxate

Transient lower esophageal sphincter relaxation (TLESR) is frequently associated with reflux events and terminates with a primary or secondary peristaltic wave. However, it is unclear whether the presence and properties of the refluxate affect TLESR-termination events. The aims of this study were to determine the pattern of terminating esophageal motor activity after TLESR in healthy subjects and factors affecting the type of terminating motor event. Fifteen healthy subjects (7 men, age 18-56) were studied. High-resolution manometry and impedance/pH monitoring were performed simultaneously in supine position for 2 h after subjects took a 1,000-kcal meal (Awake Study). This procedure was repeated during the night under polysomnographic recording for 6-8 h after consuming a 1,000-kcal meal (Sleep Study). We categorized three types of TLESR-terminating motor events, primary peristalsis (PP), full secondary contraction (FSC), which propagated the entire esophagus, and partial secondary contractions (PSC), which started distal to the upper esophageal sphincter. Overall, 289 TLESR events were found. The percentages of TLESR events terminated by PP, FSC, and PSC were 22%, 14%, and 64%, respectively. TLESR events terminated by PP were less likely to be accompanied by reflux events. TLESR events terminated by FSC were significantly more likely to have evidence for proximal esophageal reflux and esophago-pharyngeal reflux. Findings were similar in awake and sleep states. We concluded that, in healthy recumbent subjects, the most common TLESR-termination event is a secondary contraction, rather than PP. Presence and distribution of the refluxate is a major influence on the type of terminating contraction.

The efficacy and safety of ezetimibe for treatment of dyslipidemia after heart transplantation

INTRODUCTION

Statins, although the treatment of choice for dyslipidemia after heart transplantation (HT), are not always well tolerated or effective. In such cases, administration of ezetimibe may be useful.

AIM

The aim of this study was to assess the efficacy and safety of ezetimibe, with or without statins, after HT.

METHOD

Thirty-six HT patients, 97% of whom were males of overall mean age of 57 +/- 13 years, were all unable to reach target lipid levels with statins alone and/or were intolerant of statins. They were prescribed ezetimibe, with or without a statin. Efficacy and safety were evaluated after 1, 3, 6, and 12 months.

RESULTS

Thirty-four patients were evaluated at 1 month and 12 months. Ezetimibe was prescribed to 27 patients (75%) because of statin inefficacy, and to 9 patients (25%) because of statin intolerance, manifested by myalgia in 4 cases (11%), hepatotoxicity in 2 cases (6%), and rhabdomyolysis in 3 cases (8%). Lipid levels (mg/dL; baseline vs 1 year) were as follows: cholesterol, 235 +/- 49 versus 167 +/- 32 (P = .013); LDL cholesterol, 137 +/- 47 versus 89 +/- 29 (P = .001); HDL cholesterol, 54 +/- 13 versus 51 +/- 10 (P = .235); and triglycerides, 243 +/- 187 versus 143 +/- 72 (P = .022). There were no cases of liver toxicity, renal dysfunction, or significant alteration of immunosuppressive pharmacokinetics. Ezetimibe was withdrawn from 2 patients because of hand edema or asymptomatic recurrence of rhabdomyolysis first caused by statins.

CONCLUSIONS

With or without a statin, ezetimibe was generally well tolerated, reducing total cholesterol, LDL cholesterol, and triglyceride levels with no long-term alteration of HDL cholesterol levels. CPK surveillance is recommended because of a slight continued risk of adverse effects. Further studies should evaluate the benefit for survival.

Breast cancer patients' quality of care: Does racial concordance matter or is it just a matter of trust?

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Background: As insurers consider paying for performance and quality measures grow in importance, factors that affect patients' perceived quality of cancer care matter. Concordance by race in physician-patient relationships has been associated with patient satisfaction and use of health care, however how that is mediated is unclear. Methods: 210 of 300 eligible women stage I or II breast cancer at 1 of 8 participating NYC hospitals responded to our survey (70% response rate): 20% were African-American (AA), 40% were white, and 30% were Hispanic and 9% were other races. Trust is based on a validated scale and calibrated to a 100 point scale (Cronbach α = 0.76). Bivariate analyses and logistic models were used to identify factors associated with patient ratings of quality of care. Results: Only 55% of women rated the quality of their cancer care as excellent. AA women breast cancer patients were less likely to rate their care as excellent (p=0.004). Compared to women who didn't rate their care as excellent, those who rated it excellent had greater trust in their physician (p < 0.0001) and indicated that were treated well by their physicians' office staff (p = 0.01). Of note, AA patients had lower levels of trust (p = 0.004). Women who were of the same race as their physician did not perceive better quality of care as compared to those who were not racially concordant (p = 0.18); nor did they have higher trust in their physician (p = 0.59). Multivariate models evaluating the role of patient race, education, income, knowing which physician to talk to, how well the staff treated the patient, and racial concordance with physician, found that trust in physician was significantly associated with patient perception of excellent quality care (aRR = 1.38; 95%CI: 1.03–1.65) and being AA was associated with worse perceived quality (aRR = 0.47; 95%CI: 0.21–0.88) (model c = 0.79; p < 0.0001). Conclusions: Racial concordance between physicians and patients does not directly affect patients' perceived quality of care. However, women's trust in their physician and their perceived treatment by office staff are associated with excellent cancer care quality ratings. Efforts should be made to increase effective intercultural communication particularly among AA women in order to improve ratings of cancer care quality.

No significant financial relationships to disclose.

Breast cancer patients' perceived quality of care: The importance of trust and communication

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Background: As insurers consider paying for performance and quality measures grow in importance, factors that affect patients’ perceived quality of cancer care matter. We undertook this study to assess predictors of women's ratings of the quality of their breast cancer care. Methods: 210 of 300 eligible women with stage I or II breast cancer at 1 of 8 participating NYC hospitals were enrolled in our survey: 43 (20%) were African-American (AA), 85 (40%) were white, and 63 (30%) were Hispanic and 19 (9%) were other races. All patients were telephone-surveyed to assess care experiences, knowledge, attitudes & beliefs about breast cancer and its treatment. Trust is based on a validated instrument and calibrated to a 100 point scale (Cronbach α = 0.73). A scale of 5 items assessing physician communication was created and calibrated to100 points (Cronbach α = 0.83). Results: Only 55% of women rated their quality of cancer care as excellent. Compared to women who did not rate their care as excellent, those who did had greater trust in their physician (p < 0.0001), better communication with their physician (p < 0.0001), indicated that were treated well by their physicians’ office staff (p = 0.01), and knew which physician to ask when they had questions (p = 0.0001); age, education & income were not significantly related to patient report of excellent care. AA women were least likely to rate their care as excellent (p = 0.004). AA women had lower levels of trust in their physician (p = 0.02). Patients reporting greater levels of communication also had greater trust (r = 0.38; p < 0.0001). Multivariate models evaluating the role of patient race, education, income, knowing which physician to talk to and how well the staff treated the patient found that being AA (aRR = 0.47; 95% CI: 0.21–0.88), having greater trust (aRR = 1.72; 95% CI:1.49–1.85) and better communication (aRR = 1.38; 95% CI: 1.03–1.65) were significantly associated with patient perception of excellent quality care (p < 0.0001). Conclusions: Greater levels of physician communication about treatment and patient trust of their physician affect women's ratings of excellent cancer care quality. Efforts should be made to improve physician communication about treatment, particularly among AA women, to improve levels of trust and ratings of cancer care quality.

No significant financial relationships to disclose.

The economic impact of severe asthma to low-income families

BACKGROUND

To estimate the direct and indirect costs of severe asthma and the economic impact of its management to low-income families in Salvador, Brazil.

METHODS

One hundred and ninety-seven patients with severe asthma and referred to a state-funded asthma center providing free treatment were evaluated. At registration, they were asked about family cost-events in the previous year and had a baseline assessment of lung function, symptoms and quality of life. During the subsequent year, they were reassessed prospectively.

RESULTS

One hundred-eighty patients concluded a 12-month follow-up. Eighty-four percent were female patients, and the median family income was US$ 2955/year. Forty-seven percent of family members had lost their jobs because of asthma. Total cost of asthma management took 29% of family income. After proper treatment, asthma control scores improved by 50% and quality of life by 74%. The income of the families increased by US$ 711/year, as their members went back to work. The total cost of asthma to the families was reduced by a median US$ 789/family/year. Consequently, an annual surplus of US$ 1500/family became available.

CONCLUSIONS

Family costs of severe asthma consumed over one-fourth of the family income of the underprivileged population in a middle-income country. Adequate management brings major economic benefit to individuals and families.

Cervical vagal schwannoma. A case report

Schwannoma originating from the cervical vagus nerve is an extremely rare neoplasm. Vagal nerve schwannoma usually occurs between the third and fifth decades of life, it does not show sex predilection both sexes being equally affected and it most often presents as a painless, slow-growing, lateral neck mass. The treatment of choice is complete surgical excision with preservation of the neural pathway, when it is possible. These tumours, in fact, are almost always benign and a conservative surgical approach is emphasized by most of the Authors. A case of a cervical vagal schwannoma, in a 33-year old male with a previous medical history of malignant lymphoma, is described. The clinical features, diagnosis, management and pathological findings of cervical vagal schwannoma are discussed.

Substance P in nerve tissue in the gut

Substance P is present in intrinsic nerves in the intestine and in some extrinsic sensory nerves. It can be released from these nerves to act on the muscle layers and on other enteric neurons. Immunohistochemical studies show that the enteric substance P neurons are short and branch profusely to supply all intestinal layers. Pharmacological studies indicate that enteric substance P neurons receive inputs from enteric cholinergic interneurons. This suggests that these neurons are part of multineuronal nerve pathways in the intestine. The substance P neurons are not essential for the enteric reflexes which subserve peristalsis but they appear to modulate these reflexes.

Lack of control of severe asthma is associated with co-existence of moderate-to-severe rhinitis

BACKGROUND

Retrospective studies provide evidence that rhinitis is associated with more severe asthma. The aim of this study was to evaluate prospectively whether rhinitis is a predictor of increased asthma severity.

METHODS

Five hundred and fifty-seven patients with severe asthma were enrolled. During 1 year of follow-up, each patient was evaluated every 3 months with a record of emergency room visits and supply of topical corticosteroids for asthma and rhinitis. In the 1 year of follow-up visit, the patients were checked for rhinitis diagnosis, severity and answered questionnaires for asthma symptoms and quality of life.

RESULTS

Eighty-two (15%) patients had no rhinitis, 299 (54%) had mild rhinitis and 176 (31%) moderate/severe rhinitis. In logistic regression models, moderate/severe rhinitis was a predictor for any emergency room visit in the follow-up period [3.83 (2.00-7.35)], for the presence of uncontrolled asthma after 1 year of follow-up [12.68 (1.73-92.85)], for <10% improvement of the airway obstruction [2.94 (1.48-5.85)] and <50% reduction in the number of emergency room visits [2.90 (1.02-8.26)] in the year of follow-up. It was also associated with a smaller chance of more than 90% reduction in the number of emergency room visits in the year of follow-up [0.27 (0.12-0.60)]. In a multivariate linear regression model, severity of rhinitis was positively correlated with a score of asthma severity and inversely correlated to an index of quality of life.

CONCLUSIONS

In a population with severe asthma, moderate/severe rhinitis is a strong predictor for greater severity of asthma.

Detection of high-mobility group proteins A1 and A2 represents a valid diagnostic marker in post-pubertal testicular germ cell tumours

The high-mobility group A (HMGA) non-histone chromosomal proteins HMGA1 and HMGA2 are architectural factors. They are abundantly expressed during embryogenesis and in most malignant neoplasias, whereas their expression is low or absent in normal adult tissues. Their over-expression is known to have a causal role in cellular neoplastic transformation. Previous studies from our group have shown that their expression is restricted to specific germinal cells. In this study we have evaluated, by immunohistochemistry, the expression of HMGA1 and HMGA2 in a series of post-pubertal testicular tumours of different histological types, including 30 seminomas, 15 teratomas, 15 embryonal carcinomas and 10 mixed germinal tumours with a prominent yolk sac tumour component. HMGA1 protein expression was detected in all seminomas and embryonal carcinomas analysed, but not in teratomas or yolk sac carcinomas. Conversely, HMGA2 was present only in embryonal carcinomas and yolk sac carcinomas, but not in seminomas or teratomas. The immunohistochemical data were further confirmed by Western blot and, at the mRNA level, by RT-PCR analyses. These findings indicate that HMGA1 and HMGA2 are differently expressed with respect to the state of differentiation of testicular germ cell tumours (TGCTs), with over-expression of both proteins in pluripotential embryonal carcinoma cells and loss of expression of HMGA1 in yolk sac tumours and of both proteins in the mature adult tissue of teratoma areas. Therefore, the different profiles of HMGA1 and HMGA2 protein expression could represent a valuable diagnostic tool in some cases in which the histological differential diagnosis is problematic.

Sulfur-containing compounds in protecting against oxidant-mediated lung diseases

Over 95% of the oxygen we metabolize undergoes a four-electron reduction to produce two molecules of water. Whenever electrons escape from the mitochondrial electron-transport chain and pass directly onto oxygen, oxidants that can cause cytotoxicity are generated. The lung being constantly exposed to atmospheric oxygen is more susceptible to oxidant-induced cellular damage. For instance, increased generation of oxidants is implicated in many pulmonary pathological conditions including emphysema, adult respiratory distress syndrome, idiopathic pulmonary fibrosis and asthma. Sulfur is an essential major inorganic element with a recently described protective cellular role. One of its many biologically important functions is the formation of disulfide bridges between two cysteine molecules thus stabilizing protein conformation. Also, it provides the site for attachment and transfer of 1-C methyl groups via formation of S-adenosylmethionine, and most importantly it is an essential constituent of the antioxidant tripeptide, glutathione, and vitamins like thiamin and biotin. However, its protective role emanates from its antioxidant properties in the context of sulfur-containing compounds (S-adenosylmethionine, cysteine, taurine, glutathione etc) that are known to act in protecting against oxidant-induced lung disease. The efficacy of these sulfur-containing compounds in scavenging oxidants directly or indirectly and consequently protecting against lung diseases is discussed herein.

G-protein-coupled receptor heteromers: function and ligand pharmacology

Almost all existing models for G-protein-coupled receptors (GPCRs) are based on the occurrence of monomers. Recent studies show that many GPCRs are dimers. Therefore for some receptors dimers and not monomers are the main species interacting with hormones/neurotransmitters/drugs. There are reasons for equivocal interpretations of the data fitting to receptor dimers assuming they are monomers. Fitting data using a dimer-based model gives not only the equilibrium dissociation constants for high and low affinity binding to receptor dimers but also a 'cooperativity index' that reflects the molecular communication between monomers within the dimer. The dimer cooperativity index (D(C)) is a valuable tool that enables to interpret and quantify, for instance, the effect of allosteric regulators. For different receptors heteromerization confers a specific functional property for the receptor heteromer that can be considered as a 'dimer fingerprint'. The occurrence of heteromers with different pharmacological and signalling properties opens a complete new field to search for novel drug targets useful to combat a variety of diseases and potentially with fewer side effects. Antagonists, which are quite common marketed drugs targeting GPCRs, display variable affinities when a given receptor is expressed with different heteromeric partners. This fact should be taken into account in the development of new drugs.

Late noncardiac surgery in heart transplant patients

OBJECTIVE

Because of improved long-term survival of heart transplants (HT), patients often need noncardiac surgery (NCS). Immunosuppression may increase the infection rate. Inadequate management may increase the risk of dysfunction or acute rejection episodes (ARE). Long-term outcomes of NCS and optimal immunosuppressive management in the perioperative period are not well known. The objective of this study was to analyze the incidence, morbidity, and mortality of late NCS after HT.

METHODS

We retrospectively evaluated the incidence and type of late NCS as well as the risk factors for complications and the mortality among 207 HT patients. Immunosuppression and ARE rates were also analyzed.

RESULTS

One hundred and sixteen late NCS (84.5% elective) were performed in 72 HT patients (34.8%). Interventions were: 35 urologic (30.2%), 29 abdominal (25%), 14 vascular (12.1%), 13 ENT (11.2%), 11 skin and soft tissue (9.5%), and 7 orthopedic (6%). Malignancy was the main indication for NCS (33.6%). Only 4 patients (5.6%) died preoperatively. Mortality was higher among emergent vs elective procedures (16.6% vs 1%; P = .012) and among patients with preoperative high vs middle/low risk (26.6% vs 0%). Postsurgical infection was the most frequent complication (6.9%). However, there were no relevant complications in 82.8% of HT patients. Hospitalization time was <15 days in two thirds of patients. Immunosuppression was modified in 33 patients (28.4%), especially when the surgical indication was neoplasia (P < .001). None of the patients with NCS displayed allograft dysfunction or an ARE.

CONCLUSIONS

More than one-third of HT patients needed a late NCS. In our experience, elective surgical procedures with middle/low preoperative cardiovascular risk are safe. In this context, the risk of rejection was low when immunosuppression was carefully monitored to reduce the risk of infection.

The central role of glutathione in the pathophysiology of human diseases

Reduced glutathione (L-gamma-glutamyl-L-cysteinyl-glycine, GSH) is the prevalent low-molecular-weight thiol in mammalian cells. It is formed in a two-step enzymatic process including, first, the formation of gamma-glutamylcysteine from glutamate and cysteine, by the activity of the gamma-glutamylcysteine synthetase; and second, the formation of GSH by the activity of GSH synthetase which uses gamma-glutamylcysteine and glycine as substrates. While its synthesis and metabolism occur intracellularly, its catabolism occurs extracellularly by a series of enzymatic and plasma membrane transport steps. Glutathione metabolism and transport participates in many cellular reactions including: antioxidant defense of the cell, drug detoxification and cell signaling (involved in the regulation of gene expression, apoptosis and cell proliferation). Alterations in its concentration have also been demonstrated to be a common feature of many pathological conditions including diabetes, cancer, AIDS, neurodegenerative and liver diseases. Additionally, GSH catabolism has been recently reported to modulate redox-sensitive components of signal transduction cascades. In this manuscript, we review the current state of knowledge on the role of GSH in the pathogenesis of human diseases with the aim to underscore its relevance in translational research for future therapeutic treatment design.

Late Steroid Withdrawal After Heart Transplantation and Incidence of Acute Rejection

BACKGROUND

Steroid withdrawal (SW) after heart transplantation (HT) reduces steroid-associated side effects, although it can increase acute rejection episodes (ARE). Patient selection criteria for SW and the time elapsed after HT for this maneuver are controversial issues. The objective of this study was to assess the safety of late SW after HT with regard to the occurrence of ARE and to analyze risk factors resulting in a poor evolution.

METHODS

We studied a cohort of 24 patients who underwent SW late after HT. All of them had gone at least 4 years without any ARE. Independent variables were time after HT, general recipient and donor data, risk factors for ARE, and immunosuppression. The dependent variables were occurrence of ARE (proven or not proven with endomyocardial biopsy) and time and severity of ARE.

RESULTS

Among 24 HT patients including 96% men with an overall mean age of 57 years who underwent SW, the mean follow-up was 2.32 +/- 0.86 years. Six patients (25%) displayed an ARE >or=2R according to the International Society for Heart and Lung Transplantation (ISHLT) at 5 +/- 3 months after SW. There were no deaths. Time from the last rejection episode to SW was 6.6 +/- 2 years. All ARE were treated with steroid boluses (mean total dose 1583 +/- 1044 mg). Among the HT patients with ARE, 5 (85%) had never experienced ARE after HT. Upon long-term follow-up, there were 2 deaths: 1 sudden death at 30 months after SW and 1 due to allograft vasculopathy at 20 months post-SW. Currently 92% are New York Heart Association (NYHA) functional class I with a mean left ventricular ejection fraction of 67% +/- 10%.

CONCLUSIONS

In our series of HT with late SW after HT (even among an HT population with a low risk of rejection), there was a 25% rate of ARE. This study did not allow us to identify risk factors for ARE after SW. We believe that based upon these observations SW should be implemented with caution.

Physiology of Sleep Disordered Breathing

Obstructive sleep apnea (OSA) results from complex interactions between anatomy and physiology. A structurally small and abnormally collapsible upper airway predisposes to disease, and interacts with normal and pathologic physiologic mechanisms to determine severity of disease. Understanding the pathophysiology provides insight into airway collapse, and may improve treatment and lead to potential new medical and surgical treatments for OSA.

Integrated selective: An innovative teaching strategy for sleep medicine instruction for medical students

OBJECTIVES

Sleep disorders are common among all age groups, but repeated studies have demonstrated that physicians underdiagnose sleep disorders. Lack of curriculum time and the limited number of faculty with expertise in sleep medicine have been cited as major barriers for sleep medicine instruction. This paper describes the development, implementation, and evaluation of an integrated selective in sleep medicine for fourth-year medical students.

METHODS

A one-month required fourth-year integrated selective in sleep medicine was implemented at Medical College of Wisconsin (MCW). A curriculum was developed, incorporating core competencies of sleep medicine and using a combination of instructional strategies. Three sources of data were used to evaluate the selective: an elective-specific questionnaire, learner ratings, and performance on a pre- and post-knowledge test.

RESULTS

Twenty medical students (13 male; 7 female) have completed the selective to date. Lack of exposure to sleep medicine during the first three years of medical school was the most common reason for taking the elective. Student evaluation of the rotation averaged 1.5 on a five-point scale (1=best), above the average for fourth-year rotations. The mean examination scores increased significantly from pre- (56%) to post- (86%) selective (p<.05). Unanticipated but associated positive outcomes included (a) an invitation to teach a 1h lecture to third-year medical students and pediatric residents, (b) a 2h workshop on sleep medicine for internal medicine residents, and (c) grant funding from the medical college's Curriculum and Evaluation Committee to support the development of on-line sleep medicine instruction.

CONCLUSIONS

A well-designed fourth-year integrated selective improves student knowledge in sleep medicine and may provide an opening for additional inclusion of sleep medicine instruction for various trainees.

Nanodiagnostics: fast colorimetric method for single nucleotide polymorphism/mutation detection

Advances in nanosciences are having a significant impact in many areas of research. The impact of new nanotechnologies has been particularly large in biodiagnostics, where a number of nanoparticle-based assays have been introduced for biomolecules detection. To date, applications of nanoparticles have largely focused on DNA-functionalised gold nanoparticles used as the target-specific probes. These gold nanoparticle-based systems can be used for the detection of specific sequences of DNA (pathogen detection, characterisation of mutation and/or single nucleotide polymorphisms) or RNA (without prior retro-transcription and amplification). Here a rapid and inexpensive nanoparticle-based method for single-base mismatch detection (single nucleotide polymorphism/mutation) in DNA samples is reported. Gold nanoparticles derivatised with thiol modified oligonucleotides complementary to DNA targets -- Au-nanoprobes -- are used to distinguish fully complementary from mismatched sequences, with a single-base mismatch. The authors have successfully applied this strategy to detect common mutations within the beta-globin gene.

Heterodimeric adenosine receptors: a device to regulate neurotransmitter release

Since 1990 it has been known that dimers are the basic functional form of nearly all G-protein-coupled receptors (GPCRs) and that homo- and heterodimerization may play a key role in correct receptor maturation and trafficking to the plasma membrane. Nevertheless, homo- and heterodimerization of GPCR has become a matter of debate especially in the search for the precise physiological meaning of this phenomenon. This article focuses on how heterodimerization of adenosine A1 and A2A receptors, which are coupled to apparently opposite signalling pathways, allows adenosine to exert a fine-tuning modulation of striatal glutamatergic neurotransmission, providing a switch mechanism by which low and high concentrations of adenosine inhibit and stimulate, respectively, glutamate release.

Intramembrane receptor–receptor interactions: a novel principle in molecular medicine

In 1980/81 Agnati and Fuxe introduced the concept of intramembrane receptor-receptor interactions and presented the first experimental observations for their existence in crude membrane preparations. The second step was their introduction of the receptor mosaic hypothesis of the engram in 1982. The third step was their proposal that the existence of intramembrane receptor-receptor interactions made possible the integration of synaptic (WT) and extrasynaptic (VT) signals. With the discovery of the intramembrane receptor-receptor interactions with the likely formation of receptor aggregates of multiple receptors, so called receptor mosaics, the entire decoding process becomes a branched process already at the receptor level in the surface membrane. Recent developments indicate the relevance of cooperativity in intramembrane receptor-receptor interactions namely the presence of regulated cooperativity via receptor-receptor interactions in receptor mosaics (RM) built up of the same type of receptor (homo-oligomers) or of subtypes of the same receptor (RM type1). The receptor-receptor interactions will to a large extent determine the various conformational states of the receptors and their operation will be dependent on the receptor composition (stoichiometry), the spatial organization (topography) and order of receptor activation in the RM. The biochemical and functional integrative implications of the receptor-receptor interactions are outlined and long-lived heteromeric receptor complexes with frozen RM in various nerve cell systems may play an essential role in learning, memory and retrieval processes. Intramembrane receptor-receptor interactions in the brain have given rise to novel strategies for treatment of Parkinson's disease (A2A and mGluR5 receptor antagonists), schizophrenia (A2A and mGluR5 agonists) and depression (galanin receptor antagonists). The A2A/D2, A2A/D3 and A2A/mGluR5 heteromers and heteromeric complexes with their possible participation in different types of RM are described in detail, especially in the cortico-striatal glutamate synapse and its extrasynaptic components, together with a postulated existence of A2A/D4 heteromers. Finally, the impact of intramembrane receptor-receptor interactions in molecular medicine is discussed outside the brain with focus on the endocrine, the cardiovascular and the immune systems.

Receptor-receptor interactions involving adenosine A1 or dopamine D1 receptors and accessory proteins

The molecular basis for the known intramembrane receptor-receptor interactions among heptahelical receptors (G protein coupled receptors, GPCR) was postulated to be heteromerization based on receptor subtype specific interactions between different types of homomers of GPCR. Adenosine and dopamine receptors in the basal ganglia have been fundamental to demonstrate the existence of receptor heteromers and the functional consequences of such molecular interactions. The heterodimer is only one type of heteromeric complex and the evidence is equally compatible with the existence of higher order heteromeric complexes, where also adapter proteins such as homer proteins and scaffolding proteins can exist, assisting in the process of linking the GPCR and ion channel receptors together in a receptor mosaic that may have special integrative value and may constitute the molecular basis for learning and memory. Heteromerization of D(2) dopamine and A(2A) adenosine receptors is reviewed by Fuxe in another article in this special issue. Here, heteromerization between D(1) dopamine and A(1) adenosine receptors is reviewed. Heteromers formed by dopamine D(1) and D(2) receptors and by adenosine A(1) and A(2A) receptors also occur in striatal cells and open new perspectives to understand why two receptors with apparently opposite effects are expressed in the same neuron and in the nerve terminals. The role of accessory proteins also capable of interacting with receptor-receptor heteromers in regulating the traffic and the molecular physiology of these receptors is also discussed. Overall, the knowledge of the reason why such complex networks of receptor-receptor and receptor-protein interactions occur in striatal cells is crucial to develop new strategies to combat neurological and neuropsychiatric diseases.

Aβ peptides as one of the crucial volume transmission signals in the trophic units and their interactions with homocysteine. Physiological implications and relevance for Alzheimer’s disease

Amyloid peptides (Abeta) can operate as volume transmission (VT) signals since they are continuously released from cells of the central nervous system and diffuse in the extra-cellular space of the brain. They have both regulatory and trophic functions on cellular networks. In agreement with Abeta regulatory actions on glial-neuronal networks, the present paper reports new findings demonstrating that intrastriatal injections of Abeta peptides reduce striatal tyrosine hydroxylase, increase striatal GFAP immunoreactivities and lower pain threshold in experimental rats. Furthermore, it has been demonstrated that exogenous homocysteine (Hcy) binds Abeta(1-40) favouring its beta-sheet conformation both in vitro and in vivo and hence the formation of beta-fibrils and development of neurotoxicity. Thus, the hypothesis is discussed that Abeta peptides represent crucial VT-signals in the brain and their action is altered by dysmetabolic signals such as high Hcy extra-cellular levels, known to be an important risk factor for Alzheimer's disease.

Potential Roles of Electrogenic Ion Transport and Plasma Membrane Depolarization in Apoptosis

Apoptosis is characterized by the programmed activation of specific biochemical pathways leading to the organized demise of cells. To date, aspects of the intracellular signaling machinery involved in this phenomenon have been extensively dissected and characterized. However, recent studies have elucidated a novel role for changes in the intracellular milieu of the cells as important modulators of the cell death program. Specially, intracellular ionic homeostasis has been reported to be a determinant in both the activation and progression of the apoptotic cascade. Several apoptotic insults trigger specific changes in ionic gradients across the plasma membrane leading to depolarization of the plasma membrane potential (PMP). These changes lead to ionic imbalance early during apoptosis. Several studies have also suggested the activation and/or modulation of specific ionic transport mechanisms including ion channels, transporters and ATPases, as mediators of altered intracellular ionic homeostasis leading to PMP depolarization during apoptosis. However, the role of PMP depolarization and of the changes in ionic homeostasis during the progression of apoptosis are still unclear. This review summarizes the current knowledge regarding the causes and consequences of PMP depolarization during apoptosis. We also review the potential electrogenic ion transport mechanisms associated with this event, including the net influx/efflux of cations and anions. An understanding of these mechamisms could lead to the generation of new therapeutic approaches for a variety of diseases involving apoptosis.

Expression of HECA-452 in parapsoriasis and mycosis fungoides

We have investigated the HECA-452 expression in large plaque parapsoriasis (PP) and mycosis fungoides (MF) patients, evaluating the potential role of this biomarker in both cutaneous disorders. Skin specimens from 72 PP and 61 MF patients were selected in this study. We compared their actual histological diagnosis with their previous diagnosis and we found that all 72 PP patients had the same diagnosis as before (stable PP), while 26 out of 61 MF had a previous PP histological diagnosis (evolving PP). Our results show an increased expression of HECA-452 in MF compared to PP (p<0.01). Furthermore, evolving PP showed a significantly higher level of HECA-452 than stable PP (p<0.05). We conclude that HECA-452 expression increases during the natural history of Mycosis Fungoides. HECA-452 could be used as a biomarker for MF and predict which PP evolves to MF.

cAMP induced modifications of HOX D gene expression in prostate cells allow the identification of a chromosomal area involved in vivo with neuroendocrine differentiation of human advanced prostate cancers

The acquisition of epithelial-neuroendocrine differentiation (ND) is a peculiarity of human advanced, androgen-independent, prostate cancers. The HOX genes are a network of transcription factors controlling embryonal development and playing an important role in crucial adult eukaryotic cell functions. The molecular organization of this 39-gene network is unique in the genome and probably acts by regulating phenotype cell identity. The expression patterns of the HOX gene network in human prostate cell phenotypes, representing different stages of prostate physiology and prostate cancer progression, make it possible to discriminate between different human prostate cell lines and to identify loci and paralogous groups harboring the HOX genes mostly involved in prostate organogenesis and cancerogenesis. Exposure of prostate epithelial phenotypes to cAMP alters the expression of lumbo-sacral HOX D genes located on the chromosomal region 2q31-33 where the cAMP effector genes CREB1, CREB2, and cAMP-GEFII are present. Interestingly, this same chromosomal area harbors: (i) a global cis-regulatory DNA control region able to coordinate the expression of HOX D and contiguous phylogenetically unrelated genes; (ii) a prostate specific ncRNA gene associated with high-risk prostate cancer (PCGEM1); (iii) a series of neurogenic-related genes involved with epithelial-neuronal cell conversion. We report the expression of neurexin 1, Neuro D1, dlx1, and dlx2 in untreated and cAMP treated epithelial prostate cells. The in vivo expression of Neuro D1 in human advanced prostate cancers correlate with the state of tumor differentiation as measured by Gleason score. Thus, we suggest that the chromosomal area 2q 31-33 might be involved in the epithelial-ND characteristic of human advanced prostate cancers.

Periodic DFT Study of the Structural and Electronic Properties of Bulk CoAl2O4 Spinel

In this study, structural and electronic properties of CoAl2O4 spinel are investigated for the first time by means of quantum chemical computational tools. Coupling supercell periodic calculations under the density functional theory formalism with a nonempirical quasi-harmonic Debye model, we examine the influence of temperature on the relative stability of several cation distributions of Co2+ and Al3+ over tetrahedral and octahedral interstices of the oxygen sublattice. Our simulations are able to reproduce the experimentally observed trend: (i) the normal spinel is calculated to be the stable structure at static and low-temperature conditions, and (ii) as the temperature increases, the preference of structures with Al3+ at tetrahedral sites (and Co2+ at octahedral sites) is found to progress following an asymptotic conduct. The effects of the cation distributions on geometrical variations of electronic and magnetic properties of CoAl2O4 can be interpreted as dominated by the local behavior of Co2+ at octahedral sites.

CD26, adenosine deaminase, and adenosine receptors mediate costimulatory signals in the immunological synapse

Adenosine deaminase (ADA), a protein whose deficit leads to severe combined immunodeficiency, binds to the cell surface by means of either CD26, A(1) adenosine receptors, or A(2B) adenosine receptors. The physiological role of these interactions is not well understood. Our results show that by a 3-fold reduction in the EC(50) for the antigen, ADA potentiated T cell proliferation in autologous cocultures with antigen-pulsed immature or mature dendritic cells. Costimulation was not due to the enzymatic activity but to the interaction of ADA-CD26 complexes in T cells with an ADA-anchoring protein in dendritic cells. From colocalization studies, it is deduced that ADA colocalizing with adenosine receptors on dendritic cells interact with CD26 expressed on lymphocytes. This costimulatory signal in the immunological synapse leads to a marked increase (3- to 34-fold) in the production of the T helper 1 and proimmflamatory cytokines IFN-gamma, TNF-alpha, and IL-6.