Mycotoxin Profile and Phylogeny of Pathogenic Alternaria Species Isolated from Symptomatic Tomato Plants in Lebanon

The tomato is one of the most consumed agri-food products in Lebanon. Several fungal pathogens, including Alternaria species, can infect tomato plants during the whole growing cycle. Alternaria infections cause severe production and economic losses in field and during storage. In addition, Alternaria species represent a serious toxicological risk since they are able to produce a wide range of mycotoxins, associated with different toxic activities on human and animal health. Several Alternaria species were detected on tomatoes, among which the most important are A. solani, A. alternata, and A. arborescens. A set of 49 Alternaria strains isolated from leaves and stems of diseased tomato plants were characterised by using a polyphasic approach. All strains were included in the recently defined phylogenetic Alternaria section and grouped in three well-separated sub-clades, namely A. alternata (24 out of 49), A. arborescens (12 out of 49), and A. mali morpho-species (12 out of 49). One strain showed high genetic similarity with an A. limoniasperae reference strain. Chemical analyses showed that most of the Alternaria strains, cultured on rice, were able to produce alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT) and tenuazonic acid (TA), with values up to 5634, 16,006, 5156, and 4507 mg kg⁻¹, respectively. In addition, 66% of the strains were able to co-produce simultaneously the four mycotoxins investigated. The pathogenicity test carried out on 10 Alternaria strains, representative of phylogenetic sub-clades, revealed that they were all pathogenic on tomato fruits. No significant difference among strains was observed, although A. alternata and A. arborescens strains were slightly more aggressive than A. mali morpho-species strains. This paper reports new insights on mycotoxin profiles, genetic variability, and pathogenicity of Alternaria species on tomatoes.     

Improving psychological outcomes for orphans living with HIV in Tanzania through a novel intervention to improve resilience: findings from a pilot RCT

Parental death and HIV are associated with poor mental health for orphans in sub-Saharan Africa. This study aimed to evaluate a theory-based intervention for orphaned children on treatment in Tanzania, in terms of feasibility, acceptability and preliminary outcomes. A pilot RCT with nested focus group (FGD) allocated 48 children to usual care or residential “Memory Work Therapy”. Children completed outcome measures at T0 (baseline), T1 (2 weeks following intervention) and T2 (9 weeks from T0). Forty percent of eligible children assented. T1 intervention effects were found on all total measures: Brief Symptom Inventory d?=?0.99, p?<?.001; Rosenberg Self Esteem Scale d?=?0.65, p?=?.001; Strengths and Difficulties Questionnaire d?=?0.64, p?=?.002; Self-efficacy questionnaire for children both “social” and “emotional” subscales, d?=?0.54, p?=?.008 and d?=?0.63, p?=?.002, respectively. At T2, significant effects remained for all measures and SES effect increased from medium to large (T1?=?0.65, T2?=?1.33). FGD data found children valued a calm environment that met their basic needs, enabling them to reflect, highlight support resources, and strengthen ability to recognize personal skills. The intervention has strong feasibility and acceptability, with no attrition or missing data. Memory Work Therapy has high potential effect size and should be tested in a fully powered trial. Clinical trials.gov NCT02180750.     

Dealing with disclosure: Perspectives from HIV-positive children and their older carers living in rural south-western Uganda

There are limited data on the challenges faced by carers, in particular older carers, in managing the difficult task of status disclosure for HIV-positive children. We report findings from qualitative interviews with 18 care dyads of older people and HIV-positive children living in rural south-western Uganda. Our data provide insights into perceptions and norms influencing communication during and following disclosure among both carers and children, including those shaped by gendered expectations of girls’ and boys’ sexual behaviour. Young participants reported several advantages of knowing their status and showed considerable resilience in the face of HIV disclosure. Better and more support is needed to help health workers and carers (particularly older carers) manage cross-generational communication around HIV disclosure and other related aspects of sexual and reproductive health as critical aspects of children’s psychosocial development and well-being.     

Guibourtia tessmannii-induced fictive ejaculation in spinal male rat: involvement of D1, D2-like receptors

Context: Guibourtia tessmannii (Caesalpiniaceae) is a plant traditionally used as aphrodisiac. We previously reported the pro-ejaculatory effects of the aqueous and methanol extracts of G. tesmannii in spinal male rat. However, the mechanism underlying such effects has not been elucidated.

Objective: This study characterizes the dopaminergic sub-type receptors involved in G. tesmannii-induced ejaculation in male Wistar rat.

Materials and methods: Urethane-anesthetized spinal male rats were intravenously treated with saline solution (1?mL/kg, control); dopamine (0.1?μmol/kg, reference); aqueous or methanol extracts of G. tesmannii (20?mg/kg) in the absence or presence of haloperidol (0.26?μmol/kg), a nonspecific dopaminergic receptor antagonist, Sch23390 (0.26?μmol/kg), a specific D1-like receptor antagonist or, sulpiride (0.26?μmol/kg), a specific D2-like receptor antagonist. Electromyography of the bulbospongiosus muscles and intraseminal pressure were recorded after urethral, penile and drug stimulations.

Results: Urethral and penile stimulations, intravenous injection of dopamine or, aqueous and methanol extracts of G. tesmannii always triggered the expression of rhythmic contraction of the bulbospongiosus muscles with an average mean of 3.33?±?0.43; 7.83?±?0.85; 9.80?±?0.86; 0.83?±?0.54 and 2.67?±?0.95 contractions, respectively. The intraseminal pressure was more expressed after urethral and penile stimulations (15.66?±?1.58 and 13.60?±?2.40?mmHg, respectively). In rats pretreated with haloperidol, Sch23390 or sulpiride, no ejaculation was recorded after intravenous injection of G. tesmannii extracts or dopamine.

Discussion and conclusion: Guibourtia tesmannii-induced ejaculation requires the integrity of D₁ and D₂-like receptors. These findings further justify the ethno-medicinal claims of G. tesmannii as an aphrodisiac.     

Enantiomeric propanolamines as selective N-methyl-D-aspartate 2B receptor antagonists

Enantiomeric propanolamines have been identified as a new class of NR2B-selective NMDA receptor antagonists. The most effective agents are biaryl structures, synthesized in six steps with overall yields ranging from 11-64%. The compounds are potent and selective inhibitors of NR2B-containing recombinant NMDA receptors with IC 50 values between 30-100 nM. Potency is strongly controlled by substitution on both rings and the centrally located amine nitrogen. SAR analysis suggests that well-balanced polarity and chain-length factors provide the greatest inhibitory potency. Structural comparisons based on 3D shape analysis and electrostatic complementarity support this conclusion. The antagonists are neuroprotective in both in vitro and in vivo models of ischemic cell death. In addition, some compounds exhibit anticonvulsant properties. Unlike earlier generation NMDA receptor antagonists and some NR2B-selective antagonists, the present series of propanolamines does not cause increased locomotion in rodents. Thus, the NR2B-selective antagonists exhibit a range of therapeutically interesting properties.     

Pleural tuberculosis: A concise clinical review

Tuberculosis (TB) is the leading infectious cause of death worldwide, and the commonest cause of death in people living with HIV. Globally, pleural TB remains one of the most frequent causes of pleural exudates, particularly in TB‐endemic areas and in the HIV positive population. Most TB pleural effusions are exudates with high adenosine deaminase (ADA), lymphocyte‐rich, straw‐coloured and free flowing, with a low yield on mycobacterial culture. TB pleurisy can also present as loculated neutrophil‐predominant effusions which mimic parapneumonic effusions. Rarely, they can present as frank TB empyema, containing an abundance of mycobacteria. Up to 80% of patients have parenchymal involvement on chest imaging. The diagnosis is simple if M. tuberculosis is detected in sputum, pleural fluid or biopsy specimens, and the recent advent of liquid medium culture techniques has increased the microbiological yield dramatically. Where the prevalence of TB is high the presence of a lymphocyte‐predominant exudate with a high ADA has a positive predictive value of 98%. In low prevalence areas, the absence of an elevated ADA and lymphocyte predominance makes TB very unlikely, and pleural biopsy should be performed to confirm the diagnosis. Pleural biopsy for liquid culture and susceptibility testing must also be considered where the prevalence of drug resistant TB is high. Treatment regimens are identical to those administered for pulmonary TB. Initial pleural drainage may have a role in symptom relief and in hastening the resolution of the effusion. Surgical intervention may be required in loculated effusions and empyemas.     

Slowly progressive retinitis pigmentosa caused by two novel mutations in the MAK gene

Background: The growing number of clinical trials currently underway for inherited retinal diseases has highlighted the importance of achieving a molecular diagnosis for all new cases presenting to hospital eye services. The male germ cell-associated kinase (MAK) gene encodes a cilium-associated protein selectively expressed in the retina and testis, and has recently been implicated in autosomal recessive retinitis pigmentosa (RP). Whole exome sequencing has previously identified a homozygous Alu insertion in probands with recessive RP and nonsense and missense mutations have also been reported.

Materials and methods: Here we describe two novel mutations in different alleles of the MAK gene in a 75-year-old British female, who had a clinical diagnosis of RP () with onset in the fourth decade and no relevant family history. The mutations were established through next generation sequencing of a panel of 111 genes associated with RP and RP-like phenotypes.

Results: Two novel null mutations were identified within the MAK gene. The first c.1195_1196delAC p.(Thr399fs), was a two base-pair deletion creating a frame-shift in exon 9 predicted to result in nonsense-mediated decay. The second, c.279-2A>G, involved the splice acceptor consensus site upstream of exon 4, predicted to lead to aberrant splicing.

Conclusions: The natural history of this individual’s RP is consistent with previously described MAK mutations, being significantly milder than that associated with other photoreceptor ciliopathies. We suggest inclusion of MAK as part of wider genetic testing in all individuals presenting with RP.     

In vivo Ca2+ imaging of astrocytic microdomains reveals a critical role of the amyloid precursor protein for mitochondria

The investigation of amyloid precursor protein (APP) has been mainly confined to its neuronal functions, whereas very little is known about its physiological role in astrocytes. Astrocytes exhibit a particular morphology with slender extensions protruding from somata and primary branches. Along these fine extensions, spontaneous calcium transients occur in spatially restricted microdomains. Within these microdomains mitochondria are responsible for local energy supply and Ca²⁺ buffering. Using two-photon in vivo Ca²⁺ imaging, we report a significant decrease in the density of active microdomains, frequency of spontaneous Ca²⁺ transients and slower Ca²⁺ kinetics in mice lacking APP. Mechanistically, these changes could be potentially linked to mitochondrial malfunction as our in vivo and in vitro data revealed severe, APP-dependent structural mitochondrial fragmentation in astrocytes. Functionally, such mitochondria exhibited prolonged kinetics and morphology dependent signal size of ATP-induced Ca²⁺ transients. Our results highlight a prominent role of APP in the modulation of Ca²⁺ activity in astrocytic microdomains whose precise functioning is crucial for the reinforcement and modulation of synaptic function. This study provides novel insights in APP physiological functions which are important for the understanding of the effects of drugs validated in Alzheimer's disease treatment that affect the function of APP.