Buruli ulcer in Malawi - a first report

One hundred and sixty-one specimens swabbed from as many patients with chronic wounds/ulcers over a period of eight months yielded 3 acid-alcohol fast bacilli (AFB) organisms that slowly grew only at 32°C on Lowenstein-Jensen(LJ) medium producing creamy-yellow colonies between 39 and 45 days post-incubation. Mycobacterial organisms harvested from culture were strongly positive when subjected to both catalase spot test and catalase heat stability test indicating the presence of Mycobacterium ulcerans, the aetiological agent of Buruli ulcer.     

Effect of an Anaerobic Fermentation Process on 3D-Printed PLA Materials of a Biogas-Generating Reactor

3D-printed materials are present in numerous applications, from medicine to engineering. The aim of this study is to assess their suitability for an application of interest today, that of testing of 3D-printed polylactic acid (PLA)-based reactors for biogas production using anaerobic digestion. The impact of temperature, pH, and aqueous phase on the tested bioreactor is investigated, together with the effect of the gaseous phase (i.e., produced biogas). Two batches of materials used separately, one after another inside the bioreactor were considered, in a realistic situation. Two essential parameters inside the reactor (i.e., pH and temperature) were continuously monitored during a time interval of 25 to 30 days for each of the two biogas-generating processes. To understand the impact of these processes on the walls of the bioreactor, samples of 3D-printed material were placed at three levels: at the top (i.e., outside the substrate), in the middle, and at the bottom of the bioreactor. The samples were analyzed using a non-destructive imaging method, Optical Coherence Tomography (OCT). An in-house developed swept-source (SS) OCT system, master–slave (MS) enhanced, operating at a central wavelength of 1310 nm was utilized. The 3D OCT images related to the degradation level of the material of the PLA samples were validated using Scanning Electron Microscopy (SEM). The differences between the impact of the substrate on samples situated at the three considered levels inside the reactor were determined and analyzed using their OCT B-scans (optical cross-section images). Thus, the impact of the biogas-generating process on the interior of the bioreactor was demonstrated and quantified, as well as the capability of OCT to perform such assessments. Therefore, future work may target OCT for in situ investigations of such bioreactors.     

Ceramic Scaffolds for Bone Augmentation: Design and Characterization with SEM and Confocal Microscopy

Bone scaffolds must fulfil numerous and sometimes contradictory characteristics: biocompatibility, bioactivity, high porosity, and appropriate mechanical strength. To tackle some of these issues, this study has several aims for the development of such scaffolds for dentistry applications: (i) to utilize appropriate materials (ceramics and sponges) and to introduce a novel, potentially performant ceramic material; (ii) to characterize the obtained scaffolds by using a range of methods; (iii) to compare and to correlate the assessment results with the scope to validate them reciprocally. There are two commercially available dental ceramics (i.e., Ceramco iC Natural Enamel (E) and Ceramco iC Natural Dentine (D), (DeguDent GmbH, Hanau-Wolfgang, Deutschland)) that are considered, as well as a new-developed porcelain (ceramic C). To obtain porous structures of scaffolds, each ceramic is introduced in two different sponges: a denser one, green (G) and a less dense one, blue (B). A total of 60 samples are manufactured and divided in six study groups, obtained by combining the above materials: GE, BE, GD, BD, GC, and BC (where the first letter represents the sponge type and the second one the utilized ceramic). Several methods are applied to characterize their chemical composition, as well as their macro- and micro-porosity: X-ray Diffraction (XRD), apparent porosity measurements, scanning electronic microscopy (SEM), and confocal microscopy (CM). The latter two methods image the inner (porous) and the outer/cortical (denser) areas of the samples. The results show a good porosity (i.e., dimensions and uniformity of pores) of around 65% for the final group BC, with satisfactory values of around 51% for BD and GC. A certain correlation is made between SEM, CM, and the apparent porosity results. The biocompatibility of the new ceramic C is demonstrated. Finally, a necessary trade-off is made with the mechanical strength of the obtained scaffolds, which was also evaluated. From this point of view, Group BD has the highest compressive strength of around 4 MPa, while Group BC comes second, with around 2 MPa. This trade-off between porosity and mechanical strength suggests a choice between Groups BC and BD, which are the best with regard to the porosity and mechanical strength criterium, respectively.     

Hepatitis B and C in doctors and dentists in Nigeria

We surveyed a random sample (n = 75) of doctors and dentists at University College Hospital, Ibadan, Nigeria. They were offered anonymous testing for hepatitis B surface antigen (HBsAg), hepatitis Be antigen (HBeAG), antibodies to hepatitis B core antigen (anti-HBc) and to hepatitis C virus (anti-HCV), by enzyme immunoassay. The results suggest a high prevalence of hepatitis B virus (HBV) with a high potential of transmissibility, as well as a high prevalence of HCV infection. The majority of the doctors and dentists use universal precaution for protection against viral hepatitis on < 50% of the occasions when they carry out procedures on their patients. Infection with HBV was associated with type of specialty (surgeons, dentists) and lack of HBV vaccination (p < 0.05). After logistic regression, these factors were independently associated with HBV infection (p < 0.05). Sixty (80%) had not received prior HBV vaccination. Unvaccinated personnel were more likely to be surgeons, dentists, < 37 years of age, and have fewer years of professional activity (p < 0.05). After logistic regression, only fewer years of professional activity remained independently associated with lack of vaccination (p < 0.05). To reduce the occupational exposure of HBV, universal precautions must be rigorously adhered to when the doctors and dentists carry out procedures on their patients, and all health-care workers should be vaccinated with HBV vaccine and the HCV vaccine, when it becomes available.      

Psychosocial care and nutritional status of children aged 6-36 months among patrilineal (Karo) and matrilineal (Minangkabau) households in Jakarta

A study on psychosocial care among Karo (patrilineal kinship) and Minangkabau (matrilineal kinship) households who lived in Jakarta, Indonesia was aimed at investigating psychosocial care practices of mothers and the relation of psychosocial care to the nutritional status of children aged 6-36 months as indicated by Weight-for-Age (WFA), Weight-for-Height (WFH), and Height-for-Age (HFA) Z-scores. The study was a cross sectional study. The tool used to assess the psychosocial care was the Home Observation for Measurement of the Environment (HOME) inventory scale for infants and toddlers. Psychosocial care of 52 respondents from Karo and 87 from Minangkabau were generally good. Out of the total 45 items of the six sub-scales HOME inventory, 1 item in sub-scale I (Emotional and verbal responsiveness), 4 items in sub-scale II (Acceptance of child's behavior), 1 item in sub-scale IV (Provision of play materials), 1 item in sub-scale V (Parental involvement with child), and 3 items in sub-scale VI (Opportunities for variety in daily stimulation) were statistically different between the two ethnic groups. More Minangkabau children were underweight and wasting compared to Karo children. Within the Karo group, well-nourished children in terms of WFA and WHA tended to have greater total HOME scores than their underweight and wasting counterparts. Among Minangkabau group, well-nourished children in terms of WFA, WHA, and HFA tended to have greater total HOME scores than their underweight, wasting, and stunting counterparts. The total HOME score of well-nourished Karo children in terms of WFA, WFH and HFA were greater than that of well-nourished Minangkabau children.     

Corticosterone modulates noradrenaline-induced melatonin synthesis through inhibition of nuclear factor kappa B

In chronically inflamed animals, adrenal hormones exert a positive control on the secretion of melatonin by the pineal gland. In this paper, the mechanism of corticosterone as a modulator of melatonin and N-acetylserotonin (NAS) was determined. Rat pineal glands in culture, stimulated for 5 hr with noradrenaline (10 nm), were previously incubated with corticosterone (1.0 nm-1.0 microm) for 48 hr in the presence or absence of the glucocorticoid receptor (GR) antagonist, mifepristone (1.0 microm), the proteasome inhibitor, N-acetyl-leucinyl-leucinyl-norleucinal-H (ALLN, 12.5 microm) or the antagonist of the nuclear factor kappa B (NFkappaB), pyrrolidinedithiocarbamate (PDTC, 12.5 microm). Corticosterone potentiated noradrenaline-induced melatonin and NAS production in a bell-shaped manner. The increase in NAS (12.9 +/- 2.7, n=6 versus 34.3 +/- 8.3 ng per pineal) and melatonin (16.3 +/- 2.0, n=6 versus 44.3 +/- 12.9 ng per pineal) content induced by 1 microm corticosterone was blocked by mifepristone, and mimicked by ALLN and PDTC. The presence of GRs was shown by [3H]-dexamethasone binding (0.30 +/- 0.09 pmol/mg protein) and corticosterone inhibition of NFkappaB nuclear translocation was demonstrated by electromobility shift assay. Therefore, corticosterone potentiates noradrenaline-induced melatonin and NAS production through GR inhibition of NFkappaB nuclear translocation. To the best of our knowledge, this is the first time that this relevant pathway for passive and acquired immune response is shown to modulate melatonin production in pineal gland.