A plasminogen-like protease in thyroid rough microsomes degrades thyroperoxidase and thyroglobulin

Proteasome activity takes place in the cytosolic compartment and acts to degrade several proteins translated and unfolded. In transfected CHO cells expressing thyroid peroxidase (TPO), just-translated TPO undergoes proteasome activity, and then a second proteolytic system degrades more mature forms of TPO. A plasminogen-like (Pl-like) protease is found in microsomal liver membranes and in the thyroid. In the thyroid, this Pl-like protease is localized in the follicular lumen and efficiently degrades thyroglobulin (Tg) in vitro. Here we checked for the presence, in purified endoplasmic reticulum (ER) membranes of transfected CHO and in rough microsomes purified from thyroid tissue, of a second proteolytic system, different from the proteasome, and active against the two major proteins of the thyroid gland, TPO and Tg. We first confirmed that this proteolytic system was able to degrade folded endogenous TPO. We showed also that externally added TPO (folded form) was degraded by opened vesicles of ER in the same system. For thyroid tissue, we showed that added TPO, as well as purified Tg, was degraded by some unknown membrane-associated protease(s) in human and porcine thyroid rough microsomes, whereas BSA and IgG were not. These results indicated that major thyroid glycoproteins are preferential substrates of such protease(s). Immunoblot and zymography experiments identified the unknown membrane-associated protease in rough microsomes from thyroid tissues as being a Pl-like protease. These results highly suggest that this system acts as a nonproteasomal degradation enzyme at the ER level, and we hypothesize that it contributes in regulating the level of major thyroid glycoproteins.     

Prevalence and characteristics of significant social anxiety in children aged 8–13 years

Background  Social anxiety has been frequently studied in both population- and clinical-based adult and adolescent samples. Corresponding research in children is scarce and is dominated by clinical studies. The aim of the present population-based study was to examine the prevalence of significant social anxiety (SSA) in preadolescent children and compare their characteristics with those of children without SSA. The spectrum of social anxiety is explored by comparing children with different levels of social anxiety, as defined by 1–2 versus 3–5 social situations feared. Method  The sample consisted of 14,497 parents and their 3rd–7th grade children (8–13 years old) who participated in a health profile study, including questions covering DSM-IV criteria A–D for social anxiety disorder (SAD). Socio-demographic data, social and school functioning, somatic complaints, parent–child relationships, and use of health services were added to a logistic regression model to explore characteristics associated with children with, and without SSA. Associated emotional and behavioural problems were measured by the Strengths and Difficulties Questionnaire (SDQ) using parent and self-report. Results  Parents described 2.3% of all children as significantly socially anxious and 0.9% feared at least three social situations. The majority of children with SSA managed their everyday life well. However, compared with children without SSA, children with SSA struggled more often in different areas of life and showed a significantly higher prevalence of associated emotional and behavioural symptoms. Our findings also support the notion of social anxiety as a spectrum concept. Conclusions  Social anxiety problems start in childhood and can be impairing, even in non-clinical populations and in reasonably young age groups. Increased awareness of different aspects of social anxiety is needed to identify children who are at risk and to devise appropriate interventions to improve the immediate and long-term outcome.     

Nectin-4 is a new histological and serological tumor associated marker for breast cancer

Introduction

Breast cancer is a complex and heterogeneous disease at the molecular level. Evolution is difficult to predict according to classical histoclinical prognostic factors. Different studies highlight the importance of large-scale molecular expression analyses to improve taxonomy of breast cancer and prognostic classification. Identification of new molecular markers that refine this taxonomy and improve patient management is a priority in the field of breast cancer research. Nectins are cell adhesion molecules involved in the regulation of epithelial physiology. We present here Nectin-4/PVRL4 as a new histological and serological tumor associated marker for breast carcinoma.

Methods

Expression of Nectin-4 protein was measured on a panel of 78 primary cells and cell lines from different origins and 57 breast tumors by FACS analysis and immunohistochemistry (IHC), respectively. mRNA expression was measured by quantitative PCR. Serum Nectin-4 was detected by ELISA and compared with CEA and CA15.3 markers, on panels of 45 sera from healthy donors, 53 sera from patients with non-metastatic breast carcinoma (MBC) at diagnosis, and 182 sera from patients with MBC. Distribution of histological/serological molecular markers and histoclinical parameters were compared using the standard Chi-2 test.

Results

Nectin-4 was not detected in normal breast epithelium. By contrast, Nectin-4 was expressed in 61% of ductal breast carcinoma vs 6% in lobular type. Expression of Nectin-4 strongly correlated with the basal-like markers EGFR, P53, and P-cadherin, and negatively correlated with the luminal-like markers ER, PR and GATA3. All but one ER/PR-negative tumors expressed Nectin-4. The detection of Nectin-4 in serum improves the follow-up of patients with MBC: the association CEA/CA15.3/Nectin-4 allowed to monitor 74% of these patients compared to 67% with the association CEA/CA15.3. Serum Nectin-4 is a marker of disease progression, and levels correlate with the number of metastases (P = 0.038). Serum Nectin-4 is also a marker of therapeutic efficiency and correlates, in 90% of cases, with clinical evolution.

Conclusion

Nectin-4 is a new tumor-associated antigen for breast carcinoma. Nectin-4 is a new bio-marker whose use could help refine breast cancer taxonomy and improve patients' follow-up. Nectin-4 emerges as a potential target for breast cancer immunotherapy.     

Successful mitigation of delayed intestinal radiation injury using pravastatin is not associated with acute injury improvement or tumor protection

PURPOSE: To investigate whether pravastatin mitigates delayed radiation-induced enteropathy in rats, by focusing on the effects of pravastatin on acute cell death and fibrosis according to connective tissue growth factor (CTGF) expression and collagen inhibition. METHODS AND MATERIALS: Mitigation of delayed radiation-induced enteropathy was investigated in rats using pravastatin administered in drinking water (30 mg/kg/day) 3 days before and 14 days after irradiation. The ileum was irradiated locally after surgical exteriorization (X-rays, 19 Gy). Acute apoptosis, acute and late histologic alterations, and late CTGF and collagen deposition were monitored by semiquantitative immunohistochemistry and colorimetric staining (6 h, 3 days, 14 days, 15 weeks, and 26 weeks after irradiation). Pravastatin antitumor action was studied in HT-29, HeLa, and PC-3 cells by clonogenic cell survival assays and tumor growth delay experiments. RESULTS: Pravastatin improved delayed radiation enteropathy in rats, whereas its benefit in acute and subacute injury remained limited (6 h, 3 days, and 14 days after irradiation). Delayed structural improvement was associated with decreased CTGF and collagen deposition but seemed unrelated to acute damage. Indeed, the early apoptotic index increased, and severe subacute structural damage occurred. Pravastatin elicited a differential effect, protecting normal intestine but not tumors from radiation injury. CONCLUSION: Pravastatin provides effective protection against delayed radiation enteropathy without interfering with the primary antitumor action of radiotherapy, suggesting that clinical transfer is feasible.     

Quality index for the quantification of the information recorded along standard microelectrode tracks to the subthalamic nucleus in parkinsonian patients.

OBJECTIVE: To quantify the usefulness of the neuronal activity recorded on a standard microelectrode track to the subthalamic nucleus (STN) for the determination of the transition between the thalamus and the STN. METHODS: The study is based on analysis of 689 extracelullar single units recorded on 70 tracks passing through the thalamus and the STN. Using four neuron parameters that were correlated with electrode depth, a quality index (QI) for each track was computed and compared with the subjective assessment by the electrophysiologist of the track quality. RESULTS: Subjectively, the transition between the thalamus and the STN was detected in 49 tracks (usual track) and not detected on 21 tracks (unusual tracks). Objectively, spike frequency, cell burst index (BI), signal relative root mean square (RMS) and spike relative amplitude were correlated with electrode depth and used to compute track QI. The average QI index of usual and unusual tracks was 0.25 +/- 0.9 and 0.85 +/- 0.15 (mean +/- confidence interval at P < 0.001), respectively. In 20 patients, QI correlates with post-operative measurement of electrode length in the STN. CONCLUSION: These results demonstrate that simple statistical analysis taking into account the variation of single-unit characteristics with electrode depth can discriminate between useful and useless tracks for the determination of the STN localisation.     

Sleep/wake cycles in the dark: sleep recorded by polysomnography in 26 totally blind subjects compared to controls.

OBJECTIVES: To evaluate subjective sleep difficulties and nocturnal sleep with polysomnography in 26 completely blind subjects, living in normal social environments and to compare the findings with those of matched controls.METHODS: Twenty-six blind individuals with no light perception and free-running melatonin rhythms, as assessed by measurements of urinary and salivary 6-sulfatoxymelatonin, were polygraphically monitored. Actigraphy and Braille sleep logs were obtained from the individuals for 14 days. Their sleep was compared to that of matched controls.RESULTS: Blind individuals were 'free-running' despite normal and regular social interaction. Each had ordinary working conditions and/or a family life with seeing spouse and children. Actigraphy obtained on 14 successive days showed the presence of small amount of daytime 'sleep' - 24.7+/-25.1 min per day. Total sleep time, sleep latency, sleep efficiency, and total REM sleep were significantly lower than in matched controls. Working blind subjects had a slightly higher total sleep time than those retired and unemployed. Congenital blindness, acquired blindness, presence of bilateral prosthetic eyes or presence of normal human eyes did not produce different nocturnal sleep and 'free-running' pattern results.CONCLUSIONS: Reduced total sleep time and other sleep abnormalities were associated with the complaint of daytime sleepiness and poor sleep in blind subjects. The abnormalities of sleep, which may be related to the free-running condition, present an additional challenge for these subjects, who are already severely impaired by their complete lack of vision.     

Nitric oxide and sleep in the rat: a puzzling relationship.

To date, only a few studies indicate that nitric oxide may play a role in the regulation of the sleep-wake cycle. However, data reported are controversial and the part played by nitric oxide in sleep-wake cycle regulation still remains uncertain. In the present report, we studied the effects on sleep amounts of two different nitric oxide synthase inhibitors: N-nitro-L-arginine methyl ester, a non-selective nitric oxide synthase inhibitor, and 7-nitro-indazole, a specific inhibitor of neuronal nitric oxide synthase. The above compounds were administered via two routes, i.e. intraperitoneally or locally in the dorsal raphe nucleus, a structure involved in sleep regulation. In order to evaluate their efficiency to inhibit nitric oxide synthesis in the rat brain, they were first administered intraperitoneally to a group of animals, and the cortical release of nitric oxide was determined by means of voltammetric measurements. N-Nitro-L-arginine methyl ester (100 mg/kg, i.p.) did not affect the cortical release of nitric oxide, whereas it increased both slow-wave sleep and paradoxical sleep durations. On the contrary, 7-nitro-indazole (40 mg/kg, i.p.) significantly decreased the cortical release of nitric oxide (-25%) and paradoxical sleep duration. Furthermore, following microinjection of either N-nitro-L-arginine methyl ester or 7-nitro-indazole at 100 ng/0.20 microl into the nitric oxidergic cell area of the dorsal raphe nucleus, decreases in paradoxical sleep duration were obtained (-32.8% and -25.3%, respectively). The results obtained support the existence of a duality in the sleep regulation modalities exerted by nitric oxide, i.e. a peripheral inhibiting influence and a central facilitating role for the nitric oxide-serotoninergic neurons of the dorsal raphe nucleus.     

The issue of dialysis withdrawal and palliative cares. A 3-year retrospective study carried out at Grenoble university teaching hospital development of a decision-making tool

Dialysis-related constraints encourage questioning about discontinuation of treatment. In France, the 04/22/2005 law, related to patients' rights and end-of-life issues, defines bounds to treatment withdrawal, authorizing it in specific conditions, to avoid foolish obstinacy. Shortly before the publication of this law, a study has been conducted at Grenoble University Teaching Hospital, involving 31 patients followed by the dialysis service and the palliative care service, in order to analyse the circumstances in which withdrawals from dialysis happen. These patients were old and their general condition was very poor. After initiation of the questioning, treatment was removed in older patients and in those who had been dialysed for short time, which suggests they may have poor adaption to the treatment. No dialysis withdrawal was ever decided without the patient consent or without his nearest and dearest consent. After multidisciplinary discussions, a decision-making tool for dialysis withdrawal has been developed, with a view to be a starting point in the thinking process, for each decision to be adapted to each situation. This tool emphasizes the importance of time and collegial consultation in the decision-making process. It points out to that the decision lies with the referent nephrologist. After withdrawing dialysis, palliative cares must be implemented, since stopping the treatment does not mean stopping cares.