Experimental Study of the Relationship between Vitamin B12 and two Animal Tumour Systems

THE encouraging results of massive vitamin B12 dosage in treating neuroblastoma in children (Bodian, 1959) suggested a parallel investigation of the effects of this vitamin on tumours occurring in experimental animals. Initial attempts to implant tissue from human neuroblastomata were unsuccessful, and therefore a spontaneous retroperitoneal tumour of mice was obtained (C1300, Roscoe B. Jackson Memorial Laboratory, Bar Harbour, Maine). This was originally considered to be a neuroblastoma, and although it has been shown histologically to be an undifferentiated sarcoma, it was decided to test the effects of vitamin B12 upon it, together with a fibrosarcoma of rats (PWA2) to broaden the scope of the study. If vitamin B12 did affect tumour tissue, it would be reasonable to expect a relatively high uptake of the vitamin by such cells. The distribution of vitamin B12 in neoplastic and other tissues has therefore been observed in mice and rats bearing tumour transplants. As far as can be ascertained the only workers who have reported studies of the relationship of vitamin B12 to tumour growth ar

Les Cyanophyceae marines de l’île de Ngor (Sénégal)

La présente étude a été initiée dans le but de déterminer la composition taxonomique et la structure des peuplements de Cyanophyceae au niveau de l’ile de Ngor. Durant les travaux, une description basée sur des caractères morphologiques du thalle (cellule, colonie ou filament) des taxa a été effectuée. Aussi une classification et un inventaire systématique de ces taxa ont été réalisés. Six prélèvements ont été effectués entre juillet 2009 et août 2010 dans les eaux marines de l’île de Ngor située à 800 m de la côte dakaroise (Sénégal). L’observation des différents échantillons prélevés a permis de répertorier au niveau de cet écosystème 38 taxa de Cyanophyceae dont 28 identifiées jusqu’au niveau spécifique, réparties en 18 genres et 11 familles. Sur ces 11 familles, seules trois d’entre elles regroupent plus de la moitié des taxa présents. Ce sont les Oscillatoriaceae avec 31,56%, les Phormidiaceae et les Pseudanabaenaceae avec chacune 15,79%. Les Merismopediaceae représentent 10,53% des taxa, les Chroococcaceae 7,89%, et les Synechococcaceae 5,26%. Les familles des Borziaceae, des Xenococcaceae, des Hyellaceae, des Microcystaceae et des Rivulariaceae ne représentent chacune que 2,63%. Pour ce qui est des genres, Oscillatoria Vaucher est le plus représenté avec 7 taxa, suivi des genres Lyngbya C. Agardh et Phormidium Kütz. Ex Gom. avec chacun 4 taxa. Sur les 28 taxa identifiés jusqu’au niveau espèce, 17 ont été décrits pour la 1ere fois au Sénégal.Mots-clés : Cyanophyceae, composition taxonomique, structure, île de Ngor, Sénéga

The fate of the distal aorta after repair of acute type A aortic dissection

ObjectivesThe residual aorta’s behavior after repair of acute type A dissection is incompletely understood. We analyzed segmental growth rates, distal reoperation, and factors influencing long-term survival.MethodsOne hundred seventy-nine consecutive patients (70% male; mean age, 60 years) with acute type A dissection underwent aggressive resection of the intimal tear and open distal anastomosis (1986-2003). Hospital mortality was 13.4%. Survivors had serial computed tomographic scans: digitization yielded distal segmental dimensions. Segment-specific average rates of enlargement and factors influencing faster growth were analyzed. Distal reoperations and patient survival were examined.ResultsEighty-nine (57%) patients had imaging data sufficient for growth rate calculations. The median diameters after repair were as follows: aortic arch, 3.6 cm; descending aorta, 3.7 cm; and abdominal aorta, 3.2 cm. Subsequent growth rates were 0.8, 1.0, and 0.8 mm/y, respectively. Initial size of greater than 4 cm (P = .005) and initial diameter of less than 4 cm with a patent false lumen (P = .004) predicted greater growth in the descending aorta, and male sex (P = .05) significantly affected growth in the abdominal aorta. No significant factors were found for the aortic arch. There were 25 distal aortic reoperations (16 patients), and risk of reoperation was 16% at 10 years. Risk factors reducing long-term survival after repair of acute type A dissection included age (P < .0001), new neurological deficit at presentation (P = .04), absence of preoperative thrombus in the false lumen of the ascending aorta (P = .03), and a patent distal false lumen postoperatively (P = .06) but not distal reoperation.ConclusionsGrowth of the distal aorta after repair of acute type A dissection is typically slow and linear. Distal reoperation is uncommon, and late risk of death is approximately twice that of a healthy population

Miniaturised dual-modality all-optical ultrasound probe for laser interstitial thermal therapy (LITT) monitoring

All-optical ultrasound (OpUS) has emerged as an imaging paradigm well-suited to minimally invasive imaging due to its ability to provide high resolution imaging from miniaturised fibre optic devices. Here, we report a fibre optic device capable of concurrent laser interstitial thermal therapy (LITT) and real-time in situ all-optical ultrasound imaging for lesion monitoring. The device comprised three optical fibres: one each for ultrasound transmission, reception and thermal therapy light delivery. This device had a total lateral dimension of &lt;1 mm and was integrated into a medical needle. Simultaneous LITT and monitoring were performed on ex vivo lamb kidney with lesion depth tracked using M-mode OpUS imaging. Using one set of laser energy parameters for LITT (5 W, 60 s), the lesion depth varied from 3.3 mm to 8.3 mm. In all cases, the full lesion depth could be visualised and measured with the OpUS images and there was a good statistical agreement with stereomicroscope images acquired after ablation (t=1.36, p=0.18). This work demonstrates the feasibility and potential of OpUS to guide LITT in tumour resection

Flood monitoring system in the Dakar agglomeration (Senegal)

In recent decades, African cities have been confronted with series of floods linked to rapid urbanisation, intensification of heavy rains and the failure of the storm drainage system. Developing tools to characterise floods and reduce their impact is essential to facilitate decision support in a complex and vulnerable context. This study, conducted in the urban periphery of the Dakar metropolitan area, aims to propose a fine resolution (5 m) model of flows and overflows of rainwater drainage network in a pilot area. Two methodological steps are combined to achieve this objective: (1) the construction of the urban drainage topology to reconstitute the water drainage directions, taking into account the buildings, artificial channels and retention basins, using algorithms developed for this purpose, (2) simulations of the flows in real time or in project mode, using a parsimonious spatial model adapted to the local context, coupling a hydrological model (SCS-LR) on the scale of small basins with a hydraulic model (kinematic wave) for the propagation through the hydrological network. The former ensures the speed of the calculation, and the latter provides precise information on the behaviour of the network during a rainfall event. The overflow points of the network are detected by the difference between the maximum flow and the capacity of the network to evacuate floods. This modelling provides sufficiently informative simulations to guide the deployment of emergency services in the field, in real time, or to evaluate the efficiency of infrastructures in project mode, in a context of limited data. The model also provides boundary conditions for applying more complex hydraulic models to determine the impact of overtopping on limited areas.</p

Ethnobotanical study of cowpea (Vigna unguiculata (L.) Walp.) in Senegal

Open Access Article; Published online: 05 Feb 2022Cowpea (Vigna unguiculata) plays a key role in family farming systems in Senegal. It makes an essential contribution to economic, nutritional and food security. Although it is crucial, little is known about how farmers classify the diversity of local varieties or about the social practices associated with them. The aim of this study is to characterize the farming practices associated with growing cowpea in Senegal. Surveys were conducted involving 335 rural farmers living in 37 villages, spread across seven regions that produce cowpea. An average of ten farmers were randomly selected in each village. The results reveal that cowpea is a key feature of cropping systems in the studied area. Our findings highlight the high diversity of local cowpea varieties with 59 local names inventoried. In 75% of cases, the name refers to the seed’s morphology or color. Cowpea production is more diverse in Diourbel and Louga and less diverse in the south. More than half the farmers (57%) acquired their cowpea seeds (early, semi-early and late maturity varieties) outside their village, either from markets, seed suppliers or NGOs. This new understanding of farmers’ expertize in the management of cowpea and its local variability will help to valorize local diversity in breeding programs

Comparison of Fabrication Methods for Fiber‐Optic Ultrasound Transmitters Using Candle‐Soot Nanoparticles

Candle-soot nanoparticles (CSNPs) have shown great promise for fabricating optical ultrasound (OpUS) transmitters. They have a facile, inexpensive synthesis whilst their unique, porous structure enables a fast heat diffusion rate which aids high-frequency ultrasound generation necessary for high-resolution clinical imaging. These composites have demonstrated high ultrasound generation performance showing clinically relevant detail, when applied as macroscale OpUS transmitters comprising both concave and planar surfaces, however, less research has been invested into the translation of this material's technology to fabricate fiber-optic transmitters for image guidance of minimally invasive interventions. Here, are reported two fabrication methods of nanocomposites composed of CSNPs embedded within polydimethylsiloxane (PDMS) deposited onto fiber-optic end-faces using two different optimized fabrication methods: “All-in-One” and “Direct Deposition.” Both types of nanocomposite exhibit a smooth, black domed structure with a maximum dome thickness of 50 µm, broadband optical absorption (>98% between 500 and 1400 nm) and both nanocomposites generated high peak-to-peak ultrasound pressures (>3 MPa) and wide bandwidths (>29 MHz). Further, high-resolution (<40 µm axial resolution) B-mode ultrasound imaging of ex vivo lamb brain tissue demonstrating how CSNP-PDMS OpUS transmitters can allow for high fidelity minimally invasive imaging of biological tissues is demonstrated

Clinical and morphological characteristics of head-facial haemangiomas

BACKGROUND: Haemangiomas of the head or face are a frequent vascular pathology, consisting in an embryonic dysplasia that involves the cranial-facial vascular network. Haemangiomas show clinical, morphological, developmental and structural changes during their course. METHODS: The clinical characteristics of head-facial haemagiomas were studied in 28 individuals (9 males and 19 females) admitted in our Hospital. Sixteen of these patients(n = 16) underwent surgery for the removal of the haemangiomas. All the removed tissues were transferred in experimental laboratories for the staining of microanatomical details, somatic and visceral nerve fibres, adrenergic and catecholaminergic nerve fibres. Beta-adrenergic receptors were died with a fluorescent method. All results were submitted to the quantitative analysis of images and statistical evaluation of the data. RESULTS: The morphological results revealed numerous micro-anatomical characteristics of the haemangiomatous vessels. The somatic and visceral nerve fibres were poor and located exclusively in the adventitial layer. There was a marked decrease of adrenergic nerve fibres in the haemangiomatous vessels. The fluorescence of catecholaminergic nerve fibres and the overall area of fluorescent structures were also decreased in haemangiomatous vessels. Beta adrenergic receptors are strongly decreased in haemangiomatous vessels. The morphometrical analysis of images and statistical evaluation of the data confirmed all our experimental results. CONCLUSION: The catecholaminergic innervation of the human haemangiomatous vessels comprises nerve fibres containing the main catecholaminergic neurotransmitters that are sympathetic in nature. These neurotransmitters are closely related to beta-adrenergic receptors. The sympathetic nervous system plays a key role in the control of the vascular bed flow and vascular motility in both normal and haemangiomatous vessels

Laminin database: a tool to retrieve high-throughput and curated data for studies on laminins

The Laminin(LM)-database, hosted at http://www.lm.lncc.br, is the first database focusing a non-collagenous extracellular matrix protein family, the LMs. Part of the knowledge available in this website is automatically retrieved, whereas a significant amount of information is curated and annotated, thus placing LM-database beyond a simple repository of data. In its home page, an overview of the rationale for the database is seen and readers can access a tutorial to facilitate navigation in the website, which in turn is presented with tabs subdivided into LMs, receptors, extracellular binding and other related proteins. Each tab opens into a given LM or LM-related molecule, where the reader finds a series of further tabs for ‘protein’, ‘gene structure’, ‘gene expression’ and ‘tissue distribution’ and ‘therapy’. Data are separated as a function of species, comprising Homo sapiens, Mus musculus and Rattus novergicus. Furthermore, there is specific tab displaying the LM nomenclatures. In another tab, a direct link to PubMed, which can be then consulted in a specific way, in terms of the biological functions of each molecule, knockout animals and genetic diseases, immune response and lymphomas/leukemias. LM-database will hopefully be a relevant tool for retrieving information concerning LMs in health and disease, particularly regarding the hemopoietic system

Limited Trafficking of a Neurotropic Virus Through Inefficient Retrograde Axonal Transport and the Type I Interferon Response

Poliovirus is an enteric virus that rarely invades the human central nervous system (CNS). To identify barriers limiting poliovirus spread from the periphery to CNS, we monitored trafficking of 10 marked viruses. After oral inoculation of susceptible mice, poliovirus was present in peripheral neurons, including vagus and sciatic nerves. To model viral trafficking in peripheral neurons, we intramuscularly injected mice with poliovirus, which follows a muscle–sciatic nerve–spinal cord–brain route. Only 20% of the poliovirus population successfully moved from muscle to brain, and three barriers limiting viral trafficking were identified. First, using light-sensitive viruses, we found limited viral replication in peripheral neurons. Second, retrograde axonal transport of poliovirus in peripheral neurons was inefficient; however, the efficiency was increased upon muscle damage, which also increased the transport efficiency of a non-viral neural tracer, wheat germ agglutinin. Third, using susceptible interferon (IFN) α/β receptor knockout mice, we demonstrated that the IFN response limited viral movement from the periphery to the brain. Surprisingly, the retrograde axonal transport barrier was equivalent in strength to the IFN barrier. Illustrating the importance of barriers created by the IFN response and inefficient axonal transport, IFN α/β receptor knockout mice with muscle damage permitted 80% of the viral population to access the brain, and succumbed to disease three times faster than mice with intact barriers. These results suggest that multiple separate barriers limit poliovirus trafficking from peripheral neurons to the CNS, possibly explaining the rare incidence of paralytic poliomyelitis. This study identifies inefficient axonal transport as a substantial barrier to poliovirus trafficking in peripheral neurons, which may limit CNS access for other viruses