L-citrulline Prevents Alveolar and Vascular Derangement in a Rat Model of Moderate Hyperoxia-induced Lung Injury

Background

Moderate normobaric hyperoxia causes alveolar and vascular lung derangement in the newborn rat. Endogenous nitric oxide (NO), which promotes lung growth, is produced from the metabolism of l-arginine to l-citrulline in endothelial cells. We investigated whether administering l-citrulline by raising the serum levels of l-arginine and enhancing NO endogenous synthesis attenuates moderate hyperoxia-induced lung injury.

Methods

Newborn rats were exposed to FiO₂?=?0.6 or room air for 14?days to induce lung derangement and then were administered l-citrulline or a vehicle (sham). Lung histopathology was studied with morphometric features. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected for analysis. Lung vascular endothelial growth factor (VEGF), nitric oxide synthase (eNOS), and matrix metalloproteinase 2 (MMP2) gene and protein expressions were assessed.

Results

Serum l-arginine rose in the L-citr?+?hyperoxia group (p?=?0.05), as well as the Von Willebrand factor stained vessels count (p?=?0.0008). Lung VEGF immune staining, localized on endothelial cells, was weaker in the sections under hyperoxia than the l-citr?+?hyperoxia and room air groups. This pattern was comparable with the VEGF gene and protein expression profiles. Mean alveolar size increased in the untreated hyperoxia and sham-treated groups compared with the groups reared in room air or treated with l-citrulline under exposure to hyperoxia (p?=?0.0001). Lung VEGF and eNOS increased in the l-citrulline-treated rats, though this treatment did not change MMP2 gene expression but regulated the MMP2 active protein, which rose in BALF (p?=?0.003).

Conclusions

We conclude that administering l-citrulline proved effective in improving alveolar and vascular growth in a model of oxygen-induced pulmonary damage, suggesting better lung growth and matrix regulation than in untreated groups.     

Category-specific Naming Impairment for Artefacts: A New Case

Abstract

Most cases of category-specific naming and recognition disorders are characterized by poorer performance with living entities, usually animals. Patients with the less frequently observed opposite pattern of impairment, i.e. better performance with biological entities than with non-living things, provide evidence for a double dissociation, making a strong case for the categorical organization of the semantic system. We describe a patient with a category-specific naming Impairment for tools. GP is a 27-year-old student, evaluated after the evacuation of a haemorrhage in the left temporal lobe. Naming was severely impaired, without significant modality, frequency, word length or grammatical class effects. A significantly inferior performance was present for non-living items (furniture and tools). GP's performance on tests assessing comprehension of the same Items (word-picture matching, forced-choice sentence verification) suggested that semantic knowledge about artefacts he could not name was largely preserved. The localization of the lesion confirms the important role of the left anterior temporal lobe in lexical retrieval.     

Effects of cerebrolysin administration on oxidative stress-induced apoptosis in lymphocytes from CADASIL patients

Cerebrolysin (Cere) is a peptidergic nootropic drug with neurotrophic properties which has been used to treat dementia and sequelae of stroke. Use of Cere prevents nuclear structural changes typical of apoptosis and significantly reduces the number of apoptotic cells after several apoptotic stimuli. Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is a hereditary disease caused by mutations of the Notch3 gene encoding the Notch3 protein. Notch3 is involved in the regulation of apoptosis, modulating Fas-Ligand (Fas-L)- induced apoptosis. The aim of this study was to evaluate the in vitro protective effects of Cere against oxidative stress-induced apoptosis in cells from CADASIL patients. We used peripheral blood lymphocytes (PBLs) from 15 CADASIL patients (age range 34–70 years); 2-deoxy-D-ribose (dRib), a highly reducing sugar, was used as paradigm pro-apoptotic stimulus. Apoptosis was analyzed by flow cytometry and fluorescence microscopy. Administration of Cere to PBLs from CADASIL patients cultured under standard conditions had no effect on the percentage of apoptotic cells. Administration of Cere to PBLs cultured with dRib caused a significant decrease in apoptosis after 48 h of culture in only 5 patients, whereas in the other 10 patients, Cere treatment was not associated with any significant difference in the percentage of apoptosis. This result showed a protective effect of Cere against oxidative stress-induced apoptosis only in 30 % of the CADASIL patients, suggesting that the Notch3 gene probably does not influence the anti-apoptotic properties of Cere in vitro.     

Practice of yoga may cause damage of both sciatic nerves: a case report

Sciatic nerve traumatic damage very rarely occurs bilaterally. We describe the case of a 67-year-old woman who reported a bilateral traumatic lesion of the sciatic nerve during practice of yoga. Nerve conduction studies showed a bilateral sciatic nerve neuropathy, mostly affecting the peroneal component. Lumbar plexus MRI documented regular anatomical features of the main principal nerve roots with bilateral T2 signal alteration of roots L4, L5 and S1 that extended into the sciatic nerves showing both increase in size, probably related to chronic injury of nerves, and an alteration in diffusion signal that suggested a recent acute overlapped process.     

Cardiac iron removal and functional cardiac improvement by different iron chelation regimens in thalassemia major patients

Heart failure due to myocardial iron overload remains the leading cause of morbidity and mortality in adult thalassemia major (TM) patients. We evaluated the removal of cardiac iron and the changes of cardiac function by different iron chelation in TM patients by T2* cardiac magnetic resonance (CMR). Sixty-seven TM patients (27 males/40 females; mean age, 35 ± 6 years) on different chelation regimens underwent T2* CMR at baseline (t (0)), after 6-14 months (t (1)) and after 32 ± 7 months (t (2)). Patients were divided in four groups according to chelation treatment: group A (deferasirox), group B (deferoxamine), group C (combined treatment, deferoxamine plus deferiprone) and group D (deferiprone alone). Myocardial T2* at t (0) was <10 ms in 8 patients, between 10 and 20 ms in 22 patients and ≥ 20 ms in 37 patients. Progressive changes in T2* were observed at t (1) and t (2). Ten patients (10/36, 27.8 %) in group A, three patients (3/15, 20 %) in group B and three patients (3/12, 25 %) in group C moved from an abnormal T2* to normal values. We observed an improvement of left ventricular ejection fraction and a reduction of end-systolic and end-diastolic left ventricular volumes only in patients in group A with baseline cardiac T2* between 10 and 20 ms. Rigorous compliance to any chelation therapy at proper doses significantly improve myocardial T2*. Treatment with deferasirox significantly improves left ventricular function. Combination therapy seems to ameliorate cardiac T2* in a shorter period of time in severe siderosis.     

Proximity to HIV is associated with a high rate of HIV testing among men who have sex with men living in Douala, Cameroon

In low- and middle-income countries, men who have sex with men (MSM) are 19 times more likely to be HIV positive compared with background populations. Criminalisation and social rejection of homosexuality in most sub-Saharan African countries reinforce stigma and exclude MSM from prevention activities, including HIV testing. This paper's purpose is to identify factors associated with never having been HIV tested (NHT), among a sample of Cameroonian MSM. In 2008, a community-based study was conducted in Douala, the economic capital city of Cameroon, by a local NGO Alternatives-Cameroun, recruiting participants through the snowball technique and administering a questionnaire during face-to-face interviews. Proximity to HIV was investigated according to the following criteria: knowing at least one person living with HIV and having been exposed to HIV prevention interventions. NHT was defined as reporting to have never been HIV tested. A logistic regression was used to identify factors associated with NHT. Among the 165 MSM of our study group who reported that they were not HIV positive, 19% reported NHT. Factors independently associated with NHT were as follows: being younger, being Muslim, not having a steady male partner, not knowing any person living with HIV and never having been exposed to HIV prevention interventions. In this MSM population, a small proportion reported that they had never been HIV tested and among these, the percentage was higher among individuals not in proximity to HIV. Despite the hostile context of sub-Saharan African countries towards MSM, local and national HIV testing campaigns to date may have played a substantial role in raising HIV awareness in the MSM population living in Douala, and peer-based counselling may have educated those in contact with Alternatives-Cameroun regarding the positive value of HIV testing. This result is a further argument for continuing community-based prevention and extending it to difficult-to-reach MSM.