Are all forms of feature binding disturbed in schizophrenia? Evidence from a central vs. peripheral distinction in working memory

In this study we investigated central and peripheral feature binding in a group of 24 high pre-morbid IQ patients with schizophrenia and 24 healthy controls. In particular, participants were asked to remember specific single (e.g., word, colour) or multiple features (e.g., coloured words) of experimental items with central (coloured word) vs. peripheral (a coloured frame) attributes in a working memory binding task. Performance of the patients was significantly inferior to that of controls, especially when required to remember the peripheral combination of multiple features. Results suggest that patients with schizophrenia may have difficulties in unitizing peripheral features in working memory.     

Androgen and oestrogen receptors as potential prognostic markers for patients with ductal carcinoma in situ treated with surgery and radiotherapy

Ductal carcinoma in situ (DCIS) is a heterogeneous disease that has been investigated less extensively than invasive breast cancer. Women with DCIS are mainly treated with conservative surgery almost exclusively followed by radiotherapy. However, as radiation treatment is not always effective, the search for biomarkers capable of identifying DCIS lesions that could progress to invasive cancer is ongoing. Although conventional biomarkers have been thoroughly studied in invasive tumours, little is known about the role played by androgen receptor (AR), widely expressed in DCIS. A series of 42 DCIS patients treated with quadrantectomy and radiotherapy were followed for a period of up to 95 months. Of these, 11 had recurrent DCIS or progressed to invasive cancer. All tumours were analysed for clinical pathological features. Conventional biomarkers and androgen receptor expression were determined by immunohistochemistry. Our results showed that AR was higher in tumours of relapsed patients than non‐relapsed patients (P value: 0.0005). Conversely, oestrogen receptor (ER) was higher, albeit not significantly, in non‐relapsed patients than in relapsed patients. AR/ER ratio was considerably different in the two subgroups (P value: 0.0033). Area under the curve (AUC) values were 0.85 for AR and 0.80 for the AR/ER ratio. These preliminary results highlight the potentially important role of both AR and the AR/ER ratio as prognostic markers in DCIS.     

Expression of functional neurotransmitter receptors in Xenopus oocytes after injection of human brain membranes

The Xenopus oocyte is a very powerful tool for studies of the structure and function of membrane proteins, e.g., messenger RNA extracted from the brain and injected into oocytes leads to the synthesis and membrane incorporation of many types of functional receptors and ion channels, and membrane vesicles from Torpedo electroplaques injected into oocytes fuse with the oocyte membrane and cause the appearance of functional Torpedo acetylcholine receptors and Cl(-) channels. This approach was developed further to transplant already assembled neurotransmitter receptors from human brain cells to the plasma membrane of Xenopus oocytes. Membranes isolated from the temporal neocortex of a patient, operated for intractable epilepsy, were injected into oocytes and, within a few hours, the oocyte membrane acquired functional neurotransmitter receptors to gamma-aminobutyric acid, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, kainate, and glycine. These receptors were also expressed in the plasma membrane of oocytes injected with mRNA extracted from the temporal neocortex of the same patient. All of this makes the Xenopus oocyte a more useful model than it already is for studies of the structure and function of many human membrane proteins and opens the way to novel pathophysiological investigations of some human brain disorders.     

Ghrelin does not mediate the somatotroph and corticotroph responses to the stimulatory effect of glucagon or insulin-induced hypoglycaemia in humans

OBJECTIVE: Acylated ghrelin, a gastric peptide, possesses a potent GH- but also significant ACTH/cortisol-releasing activity mediated by the activation of GH secretagogue receptors (GHS-R) at the hypothalamus-pituitary level. The physiological role of ghrelin in the control of somatotroph and corticotroph function is, however, largely unclear. Glucagon is known to induce a clear increase of GH, ACTH and cortisol levels in humans, at least after intramuscular administration. In fact, glucagon is considered to be a classical alternative to insulin-induced hypoglycaemia (ITT) for the combined evaluation of the function of GH and the hypothalamus-pituitary-adrenal (HPA) axis. We aimed to clarify whether ghrelin mediate the GH and corticotroph responses to intramuscular glucagon or ITT, which has recently been reported able to induce a surprising ghrelin decrease. SUBJECTS: To this aim we enrolled six normal young male subjects [age (mean +/- SD): 29.0 +/- 8.0 years, body mass index (BMI) 21.9 +/- 2.5 kg/m(2)]. DESIGN AND MEASUREMENTS: In all the subjects we studied ghrelin, GH, ACTH, cortisol and glucose levels after glucagon (GLU; 0.017 mg/kg intramuscularly), ITT (0.1 IU/kg insulin intravenously) or saline administration. RESULTS: Saline infusion was not followed by any significant variation in ghrelin, GH and glucose levels while ACTH and cortisol showed the expected spontaneous morning trend toward a decrease. GLU administration increased (P < 0.01) circulating GH, ACTH and cortisol as well as insulin and glucose levels. ITT induced an obvious increase (P < 0.01) of GH, ACTH and cortisol levels. The ITT-induced increases in GH and ACTH, but not cortisol, levels were higher (P < 0.01) than those after GLU. Circulating ghrelin levels were not modified by GLU. On the other hand, ghrelin levels underwent a transient reduction (P < 0.01) after insulin-induced hypoglycaemia. CONCLUSIONS: Ghrelin does not mediate the GH and ACTH responses to glucagon or to the ITT. In fact, ghrelin levels are not modified at all by glucagon and transiently decrease during the ITT. These findings support the assumption that ghrelin does not play a major role in the physiological control of somatotroph and corticotroph function.     

Melatonin antagonizes the intrinsic pathway of apoptosis via mitochondrial targeting of Bcl-2

Abstract:  We have recently shown that melatonin antagonizes damage-induced apoptosis by interaction with the MT-1/MT-2 plasma membrane receptors. Here, we show that melatonin interferes with the intrinsic pathway of apoptosis at the mitochondrial level. In response to an apoptogenic stimulus, melatonin allows mitochondrial translocation of the pro-apoptotic protein Bax, but it impairs its activation/dimerization The downstream apoptotic events, i.e. cytochrome c release, caspase 9 and 3 activation and nuclear vesiculation are equally impaired, indicating that melatonin interferes with Bax activation within mitochondria. Interestingly, we found that melatonin induces a strong re-localization of Bcl-2, the main Bax antagonist to mitochondria, suggesting that Bax activation may in fact be antagonized by Bcl-2 at the mitochondrial level. Indeed, we inhibit the melatonin anti-apoptotic effect (i) by silencing Bcl-2 with small interfering RNAs, or with small-molecular inhibitors targeted at the BH3 binding pocket in Bcl-2 (i.e. the one interacting with Bax); and (ii) by inhibiting melatonin-induced Bcl-2 mitochondrial re-localization with the MT1/MT2 receptor antagonist luzindole. This evidence provides a mechanism that may explain how melatonin through interaction with the MT1/MT2 receptors, elicits a pathway that interferes with the Bcl-2 family, thus modulating the cell life/death balance.     

The Proteolytic Fraction from Latex of <Emphasis Type="Italic">Vasconcellea cundinamarcensis</Emphasis> (P1G10) Enhances Wound Healing of Diabetic Foot Ulcers: A Double-Blind Randomized Pilot Study

Introduction

The aim of the study was to investigate the role of the proteolytic fraction from Vasconcellea cundinamarcensis, designated as P1G10, on the healing of chronic foot ulcers in neuropathic patients with diabetes 2.

Methods

Fifty patients were enrolled in a prospective, randomized, double-blind trial, to verify the efficacy and safety of a topical dressing formulated with 0.1% P1G10, intended for wound healing, versus a hydrogel (control) protocol. Upon completion of the intervention, the outcome evaluated the number of patients attaining full epithelization (100%), or at least 80% healing. Statistical analysis compared the data on each group for the significance of the differences.

Results

Collection of data was finished in week 16, and the results were analyzed by intention to treat. The results showed that, in the control group, 5 patients attained 100% ulcer healing, 3 patients?≥?80% healing and 11 experienced ulcer changes?≤?80%, and the remainder showed no changes or their wounds became worse. Meanwhile, in the P1G10 group, 11 patients experienced full healing, 4 had healing?≥?80% and 5 had ulcer changes?≤?lower than 80%, and the remainder showed no changes or their wounds became worse. The healing incidence for the first endpoint (100% healing) showed that the P1G10 group was 2.95-fold more efficacious than the control group (CI 95%) and 2.52-fold (CI, 95%) higher than its control for the second endpoint (80% healing).

Conclusions

These data support the hypothesis that topical application of the proteolytic fraction identified as P1G10 significantly enhances foot ulcer healing compared to hydrogel treatment.