Perspectives on training in obstetrics and gynaecology during the COVID-19 pandemic: Thematic analysis of trainee responses from a pan-European survey

Background

Coronavirus disease 19 (COVID-19) has affected many aspects of the lives of medical professionals. Postgraduate training has also been affected and mitigation plans are still ongoing.

Objective

To understand the perspectives of trainees in obstetrics and gynaecology (ObGyn) during the pandemic.

Materials and Methods

A cross-sectional exploratory survey conducted electronically from 20th of April 2020 to 1st July 2020.

Main outcome measures

The original questionnaire comprised of 40 questions and a free-text option. The free-text questions covered five main domains: effect of the pandemic on training, worries about training, acquisition of skills during the pandemic, training period and extensions and responsibilities outside training during the pandemic. The responses to these questions in the survey were analysed using pragmatic thematic analysis.

Results

Trainees felt there was lack of training as well as training opportunities. Some took the pandemic as an opportunity to gain new skills. Trainees were also worried about time in training and uncertainty about extensions. Lastly, many had concerns pertaining to patient care, an inability to contribute to departmental organisation, and dissatisfaction with the implemented policies.

Conclusion

The difficulties in Obstetrics and gynaecology training due to the pandemic need to be mitigated. When planning for reshaping the training programmes to accommodate for the discrepancies caused, trainers need to consider the perspectives of trainees and actively involve them in the decision making, designing and executing future plans.

What is new?

Efforts are currently underway to address the training time lost during the pandemic in Europe. Recognising the paramount importance of providing exceptional care for women and children across the continent, it becomes imperative to consider the valuable perspectives and insights offered by those who represent the future generation of specialists in the field.

Combined Application of Antisense Oligomers to Control Transcription Factors of Candida albicans Biofilm Formation

Antisense oligomers (ASOs) have been little exploited to control determinants of Candida albicans virulence. Biofilm formation is an important virulence factor of C. albicans, that is regulated by a complex network of transcription factors (such as EFG1, BRG1 and ROB1). Thus, the main goal of this work was to project ASOs, based on the 2'-OMethyl chemical modification, to target BRG1 and ROB1 mRNA and to validate its application either alone or in combination with the EFG1 mRNA target, to reduce C. albicans biofilm formation. The ability of ASOs to control gene expression was evaluate by qRT-PCR. The effect on biofilm formation was determined by the total biomass quantification, and simultaneously the carbohydrates and proteins reduction on extracellular matrix. It was verified that all the oligomers were able to reduce the levels of gene expression and the ability of C. albicans to form biofilms. Furthermore, the combined application of the cocktail of ASOs enhances the inhibition of C. albicans biofilm formation, minimizing biofilm thickness by reducing the quantity of matrix content (protein and carbohydrate). So, our work confirms that ASOs are useful tools for research and therapeutic development on the control of Candida species biofilm formation.

Eliminating measles: contributions by the Oporto international vaccination centre from 2017 to 2018

Background

Measles is one of world's most contagious diseases and a growing population mobility has promoted its spreading. Outbreaks have been recorded around the world, despite public health efforts. Measles spreads faster among clusters of unvaccinated people. In 2018, World Health Organization reported 328629 cases worldwide, of which 82596 in Europe and 171 in Portugal- 93% of the latter were imported. Portugal had one of the highest proportions of childhood immunization coverage for Measles-Mumps-Rubella (MMR): 98% for first dose, and 96-98% for second. The main goal of this study was to describe the contribution of the Oporto International Vaccination Centre (OIVC), one of the largest in Portugal, to measles elimination.

Methods

Cross-sectional study, with analysis of vaccination records from travelers vaccinated for MMR at OIVC between January 2017 and December 2018.

Results

OIVC held 5426 pre-travel consultations in 2017, and 6192 in 2018. 535 travelers got the MMR vaccine (57.2% males). Mean age was 44.3±10.9 [1;76] years. Among travelers aged 12 months-18 years (n = 10), 50% were inoculated with the first dose and 50% with the second. Regarding adult travelers (n = 525), 71.6% received the first dose; 24.2% the second; 2.9% the third dose; and 1.3% received both first and second (within > 4 weeks).

Conclusions

The substantial number of inoculated vaccines in OIVC resulted from checking traveler's vaccination immunity status in all pre-travel consultations; this routine practice aimed at reducing the risk of importing/exporting measles. The second dose of MMR was justified by the diversity of travelers who came to OIVC, and to whom such inoculation was indicated: health professionals, humanitarian travelers, and workers in airlines and cruises. The third dose was given due to loss of measles serologic immunity. These measures are important to implement the recommendations of the Measles National Elimination Program, while contributing to global public health.

Key messages

This is an original study on the contribution of international vaccination centers to reduce the number of imported/exported cases and to eliminate measles - which is a global public health issue. At a global level, measles has a large disease burden. Therefore, it is essential to take every opportunity, including pre-travel consultations, to vaccinate people.

Histoplasmose Cutânea Disseminada em Doente com SIDA: Relato de um Caso Clínico

Descreve-se o caso clínico duma mulher de 30 anos, raça negra, natural e residente em Moçambique, internada no serviço de dermatologia do Hospital Central de Maputo por múltiplas pápulas de aparecimento progressivo e aditivo disseminadas por todo o tegumento cutâneo. O teste para VIH 2 foi positivo, com CD4 de 1 cel/mm3. O exame histológico de uma das lesões foi compatível com infecção por Histoplasma capsulatum. Foi medicada com anfotericina B durante 21 dias com melhoria clínica. Teve alta medicada com fluconazol 400 mg/dia e tratamento anti-retroviral mas viria a falecer 13 meses depois após gastrenterite aguda.

Influence of Sub-Inhibitory Concentrations of Antimicrobial Agents on Biofilm Formation in Indwelling Medical Devices

Biofilms of Staphylococcus epidermidis and Candida spp. are two of the most frequent factors of infections associated with the use of indwelling medical devices. Several strategies have been proposed and/or developed to prevent infection. The aim of this study was to compare the effect of sub-inhibitory concentrations of anti-microbial agents on biofilm formation.

Biofilms of three strains of S. epidermidis and two of both Candida albicans and Candida dubliniensis were formed in the presence of three antibiotics and two antifungal agents respectively. Based on the control samples, the percentage of biofilm formation inhibition by the different agents was determined and compared.

The results showed that the influence of the antibacterial and antifungal agents tested is strain dependent, with the effect of the different agents also varying among strains, even though they have the same mechanism of action.

Detection of rabbit Haemorrhagic disease virus 2 during the wild rabbit (Oryctolagus cuniculus) eradication from the Berlengas archipelago, Portugal

BACKGROUND

In the regular wildlife monitoring action carried out in the summer of the past few years at the Berlenga Island, wild rabbits (Oryctolagus cuniculus) have been repeatedly found dead. However, the origin of those deaths was never investigated. Our aim was to investigate the cause of death of 11 rabbits collected between April and May 2016.

RESULTS

While screening samples from rabbit carcasses for the major viral rabbit pathogens, five tested positive to RHDV2 but all were negative for RHDV and myxoma virus (MYXV). For six RHDV2-negative specimens, emaciation and parasitism were considered the most probable cause of death. Lesions identified in the RHDV2-positive rabbits included non-suppurative diffuse hepatic necrosis and pulmonary lesions varying from congestion and oedema of the lungs to interstitial pneumonia. Sequencing analysis of the vp60 gene obtained from two specimens showed identical vp60 sequences. Comparison with other known RHDV2 strains from public databases through BLAST analysis revealed a closer similarity with strains from Alentejo collected during 2013. Maximum Likelihood and Bayesian phylogenetic analysis showed that the 2016 strains from the archipelago have a higher resemblance with a group of strains mostly collected in the South of Portugal between 2013 and 2014.

CONCLUSION

The results suggest that RHDV2 may have been introduced on the Berlenga Island a few years ago, having evolved separately from mainland strains due to insularity.

Candida glabrata's recurrent infections: biofilm formation during Amphotericin B treatment

Candida species are responsible for recurrent human infections, mostly in immunocompromised patients, due to their high vulnerability. Candida glabrata has a major role in systemic candidiasis and Amphotericin B (AmB), a polyene only used in hospitals, is frequently used to treat this disease. Lately, however, clinical evidences of Candida recurrent infections during these treatments are being described, probably due to biofilm (re)formation during this therapy. Thus, this work aims at inferring if C. glabrata biofilms are still being formed during AmB treatment. For that, C. glabrata biofilms were formed in the presence of AmB and analysed by dry weight. Matrix composition was analysed quantifying carbohydrates and, specifically, β-1,3 glucans. Results demonstrated that, although in a lesser extent, C. glabrata is able to develop biofilms in the presence of AmB, with a thick extracellular matrix, with an increase on carbohydrates, especially β-1,3 glucans. Therefore, it is confirmed that complex biofilms of C. glabrata can be formed during an AmB treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows new insights regarding recurrent candidiasis. The authors demonstrated that Amphotericin B did not totally prevent the development of biofilms during Candida glabrata's infection treatment and that the change in the biofilm matrices may have a high responsibility for the fail in the treatment of systemic candidiasis.

TiO2nanotubes enriched with calcium, phosphorous and zinc: promising bio-selective functional surfaces for osseointegrated titanium implants

TiO₂nanotubes enriched with Ca, P, and Zn by reverse polarization anodization, are promising bio-selective functional structures for osseointegrated titanium implants.

Candida albicans and Candida dubliniensis: comparison of biofilm formation in terms of biomass and activity

Candida albicans and C. dubliniensis are two species responsible for oral candidiasis, especially in immunocompromised patients. Microbial infection is preceded by adherence and biofilm formation. Biofilm formation represents the most common form of C. albicans in the oral cavity and is considered to be one of the most important virulence factors. In this study, the biofilm formation ability of C. dubliniensis was compared with that of C. albicans in terms of biomass (quantified using crystal violet) and activity (assessed by formazan salts formation). Both species formed heterogeneous biofilms; however, species and strain variations were seen in the quantification of biomass and activity. There was no correlation between pseudohyphae formation and biofilm formation capability.

MC3T3-E1 Cell Response to Ti1-xAgx and Ag-TiNx Electrodes Deposited on Piezoelectric Poly(vinylidene fluoride) Substrates for Sensor Applications

In the sensors field, titanium based coatings are being used for the acquisition/application of electrical signals from/to piezoelectric materials. In this particular case, sensors are used to detect dynamic mechanical loads at early stages after intervention of problems associated with prostheses implantation. The aim of this work is to select an adequate electrode for sensor applications capable, in an initial stage to avoid bone cell adhesion, but at a long stage, permit osteointegration and osteoinduction. This work reports on the evaluation of osteoblast MC3T3-E1 cells behavior in terms of proliferation, adhesion and long-term differentiation of two different systems used as sensor electrodes: Ti1-xAgx and Ag-TiNx deposited by d.c. and pulsed magnetron sputtering at room temperature on poly(vinylidene fluoride) (PVDF). The results indicated an improved effect of Ag-TiNx electrodes compared with Ti1-xAgx and TiN, in terms of diminished cell adhesion and proliferation at an initial cell culture stage. Nevertheless, when cell culture time is longer, cells grown onto Ag-TiNx electrodes are capable to proliferate and also differentiate at proper rates, indicating the suitability of this coating for sensor application in prostheses devices. Thus, the Ag-TiNx system was considered the most promising electrode for tissue engineering applications in the design of sensors for prostheses to detect dynamic mechanical loads.

Biotribocorrosion (tribo-electrochemical) characterization of anodized titanium biomaterial containing calcium and phosphorus before and after osteoblastic cell culture

The purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell-biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry.

Candida glabrata: a review of its features and resistance

Candida species belong to the normal microbiota of the oral cavity and gastrointestinal and vaginal tracts, and are responsible for several clinical manifestations, from mucocutaneous overgrowth to bloodstream infections. Once believed to be non-pathogenic, Candida glabrata was rapidly blamable for many human diseases. Year after year, these pathological circumstances are more recurrent and problematic to treat, especially when patients reveal any level of immunosuppression. These difficulties arise from the capacity of C. glabrata to form biofilms and also from its high resistance to traditional antifungal therapies. Thus, this review intends to present an excerpt of the biology, epidemiology, and pathology of C. glabrata, and detail an approach to its resistance mechanisms based on studies carried out up to the present.

Silver colloidal nanoparticles: effect on matrix composition and structure of Candida albicans and Candida glabrata biofilms

AIM

The aim of this study was to assess the effect of different silver nanoparticles (SN) concentrations on the matrix composition and structure of Candida albicans and Candida glabrata biofilms.

METHODS AND RESULTS

Candida biofilms were developed in 6-well microtiter plates during 48 h. After, these biofilms were exposed to 13.5 or 54 μg SN ml(-1) for 24 h. Then, extracellular matrices were extracted from biofilms and analysed chemically in terms of proteins, carbohydrates and DNA. To investigate the biofilm structure, scanning electron microscopy (SEM) and epifluorescence microscopy were used. SN interfered with the matrix composition of Candida biofilms tested in terms of protein, carbohydrate and DNA, except for the protein content of C. albicans biofilm. By SEM, Candida biofilms treated with SN revealed structural differences, when compared with the control groups. Further, SN showed a trend of agglomeration within the biofilms. Epifluorescence microscopy images suggest that SN induced damage on cell walls of the Candida isolates tested.

CONCLUSIONS

In general, irrespective of concentration, SN affected the matrix composition and structure of Candida biofilms and these findings may be related to the mechanisms of biocide action of SN.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study reveals new insights about the behaviour of SN when in contact with Candida biofilms. SN may contribute to the development of therapies to prevent or control Candida infections.

Silver nanoparticles: influence of stabilizing agent and diameter on antifungal activity against Candida albicans and Candida glabrata biofilms

AIM

  The purpose of this work was to evaluate the size-dependent antifungal activity of different silver nanoparticles (SN) colloidal suspensions against Candida albicans and Candida glabrata mature biofilms.

METHODS AND RESULTS

  The research presented herein used SN of three different average sizes (5, 10 and 60 nm), which were synthesized by the reduction of silver nitrate through sodium citrate and which were stabilized with ammonia or polyvinylpyrrolidone. Minimal inhibitory concentration (MIC) assays were performed using the microdilution methodology. The antibiofilm activity of SN was determined by total biomass quantification (by crystal violet staining) and colony forming units enumeration. MIC results showed that all SN colloidal suspensions were fungicidal against the tested strains at very low concentrations (0·4-3·3 μg ml(-1) ). With regard to biomass quantification, SN colloidal suspensions were very effective only against C. glabrata biofilms, achieving biomass reductions around 90% at a silver concentration of 108 μg ml(-1) . In general, all SN suspensions promoted significant log(10) reduction of the mean number of cultivable biofilm cells after exposure to silver concentrations at or higher than 108 μg ml(-1) . Moreover, the results showed that the particle size and the type of stabilizing agent used did not interfere in the antifungal activity of SN against Candida biofilms.

CONCLUSIONS

  This study suggests that SN have antifungal therapeutic potential, but further studies are still required namely regarding formulation and delivery means.

SIGNIFICANCE AND IMPACT OF THE STUDY

  SN may contribute to the development of new strategies for the improvement of oral health and quality of life particularly of the complete denture wearers.

Polidactilia pré-axial. Experiência no Hospital de Santa Maria (Lisboa) nos últimos 10 anos, e 2 casos clínicos pouco frequentes

A polidactilia é a malformação congénita mais frequente da mão e membro superior, habitualmente classificada em radial, central e cubital.

Objectivo: Avaliar os resultados estéticos e funcionais após correcção cirúrgica de polidactilia radial no Hospital de Santa Maria em Lisboa nos últimos 10 anos. Apresentam-se ainda dois casos clínicos: uma criança com polidactilia radial tipo VII de Wassel bilateral e uma jovem com polidactilia radial tipo IV de Wassel submetida a intervenção cirúrgica já em idade adulta.

Material e Método: Realizaram-se sete cirurgias, em seis doentes: comprimento e largura do polegar, forma e dimensões da unha e capacidade de pinça pollici-digital foram avaliados, comparando-se com o lado contralateral nos casos unilaterais e com valores padrão no caso de bilateralidade. Foram também submetidos a avaliação o resultado estético e a repercussão emocional da cirurgia.

Conclusão: Nos casos de polidactilia a intervenção cirúrgica é a única forma de se conseguir um polegar único, funcional e esteticamente aceitável, tendo em conta a reconstrução esquelética e articular e o reposicionamento dos feixes vasculo-nervosos, tendões e músculos intrínsecos do polegar. Uma avaliação préoperatória cuidada; a selecção do tipo de cirurgia e a experiência do cirurgião são factores que contribuem para a taxa de sucesso alcançada.

Insights into Candida tropicalis nosocomial infections and virulence factors

Candida tropicalis is considered the first or the second non-Candida albicans Candida (NCAC) species most frequently isolated from candidosis, mainly in patients admitted in intensive care units (ICUs), especially with cancer, requiring prolonged catheterization, or receiving broad-spectrum antibiotics. The proportion of candiduria and candidemia caused by C. tropicalis varies widely with geographical area and patient group. Actually, in certain countries, C. tropicalis is more prevalent, even compared with C. albicans or other NCAC species. Although prophylactic treatments with fluconazole cause a decrease in the frequency of candidosis caused by C. tropicalis, it is increasingly showing a moderate level of fluconazole resistance. The propensity of C. tropicalis for dissemination and the high mortality associated with its infections might be strongly related to the potential of virulence factors exhibited by this species, such as adhesion to different host surfaces, biofilm formation, infection and dissemination, and enzymes secretion. Therefore, the aim of this review is to outline the present knowledge on all the above-mentioned C. tropicalis virulence traits.

Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata

The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

Crystal violet staining to quantify Candida adhesion to epithelial cells

In vitro studies of adhesion capability are essential to characterise the virulence of Candida species. However, the assessment of adhesion by traditional methods is time-consuming. The aim of the present study is the development of a simple methodology using crystal violet staining to quantify in vitro adhesion of different Candida species to epithelial cells. The experiments are performed using Candida albicans (ATCC 90028), C. glabrata (ATCC 2001), C. parapsilosis (ATCC 22019) and C. tropicalis (ATCC 750). A human urinary bladder epithelial cell line (TCC-SUP) is used. Yeast and epithelial cells were stained with crystal violet, epithelial cells were then destained using intermediate washing, and the dye in the yeast cells was extracted with acetic acid. The method was validated for the different Candida reference species by comparison with traditional microscope observation and enumeration. The method was then used to assess Candida adhesion to epithelial cells and also to silicone. For all Candida spp. high correlation values (r2= 0.9724-0.9997) between the number of adherent yeasts (microscope enumeration) and absorbance values were obtained for an inoculum concentration >10(6) cells/mL. The proposed technique was easy to perform and reproducible, enabling the determination of adhesion ability of Candida species to an epithelial cell line.

The role of secreted aspartyl proteinases in Candida tropicalis invasion and damage of oral mucosa

Candida virulence attributes include the ability to colonize and invade host tissues, and the secretion of hydrolytic enzymes. Although Candida albicans is regarded as the principal fungi causing infections in humans, other species, particularly Candida tropicalis, are increasingly being recognized as human pathogens. Relatively little is known, however, about the virulence attributes associated with C. tropicalis. The present study aimed to investigate epithelial infection by C. tropicalis using a reconstituted human oral epithelium (RHOE) together with confocal laser scanning microscopy and real-time PCR. A comparison of clinical strains was made in terms of tissue colonization, invasion and C. tropicalis secreted aspartyl proteinase (SAPT) gene expression. All C. tropicalis strains were able to colonize RHOE in a strain-dependent manner. After 12 h of infection, C. tropicalis was found to be highly invasive, with extensive tissue damage occurring after 24 h. Real-time PCR of C. tropicalis SAPT1-4 genes showed that expression was strain-dependent, with SAPT2-4 transcripts being frequently detected and SAPT1 rarely detected. Tissue invasion and damage was not inhibited by the presence of pepstatin A. Accordingly, and given that an increase in infection time was not accompanied with an increase in SAPT gene expression, it can be suggested that the proteinases are not involved in invasion and damage of RHOE by C. tropicalis. In summary, C. tropicalis can be considered as highly invasive with the ability to induce significant tissue damage. These features, however, do not appear to be related to specific SAPT gene expression.

Biofilms Inducing Ultra-low Friction on Titanium

Biofilm formation is widely reported in the literature as a problem in the healthcare, environmental, and industrial sectors. However, the role of biofilms in sliding contacts remains unclear. Friction during sliding was analyzed for titanium covered with mixed biofilms consisting of Streptococcus mutans and Candida albicans. The morphology of biofilms on titanium surfaces was evaluated before, during, and after sliding tests. Very low friction was recorded on titanium immersed in artificial saliva and sliding against alumina in the presence of biofilms. The complex structure of biofilms, which consist of microbial cells and their hydrated exopolymeric matrix, acts like a lubricant. A low friction in sliding contacts may have major significance in the medical field. The composition and structure of biofilms are shown to be key factors for an understanding of friction behavior of dental implant connections and prosthetic joints. For instance, a loss of mechanical integrity of dental implant internal connections may occur as a consequence of the decrease in friction caused by biofilm formation. Consequently, the study of the exopolymeric matrix can be important for the development of high-performance novel joint-based systems for medical and other engineering applications.

Do oral biofilms influence the wear and corrosion behavior of titanium?

The main aim of this work was to study the simultaneous wear-corrosion of titanium (Ti) in the presence of biofilms composed of Streptococcus mutans and Candida albicans. Both organisms were separately grown in specific growth media, and then mixed in a medium supplemented with a high sucrose concentration. Corrosion and tribocorrosion tests were performed after 48 h and 216 h of biofilm growth. Electrochemical corrosion tests indicated a decrease in the corrosion resistance of Ti in the presence of the biofilms although the TiO(2) film presented the characteristics of a compact oxide film. While the open circuit potential of Ti indicated a tendency to corrosion in the presence of the biofilms, tribocorrosion tests revealed a low friction on biofilm covered Ti. The properties of the biofilms were similar to those of the lubricant agents used to decrease the wear rate of materials. However, the pH-lowering promoted by microbial species, can lead to corrosion of Ti-based oral rehabilitation systems.

Reduction of Staphylococcus epidermidis adhesion to indwelling medical devices: a simple procedure

The present study aims to find a method to reduce Staphylococcus epidermidis adhesion to acrylic and silicone--two materials used commonly in medical devices--by heparin and gentian violet surface preconditioning. Different periods of heparin preconditioning are studied to evaluate the influence of preincubation time on the reduction of bacterial adhesion. A two-hour period was chosen and applied in the adhesion assays with either heparin or gentian violet. Squares of the materials with adherent cells were also analysed by scanning electron microscopy (SEM). Results of adhesion assays showed a significant reduction (53-90%, P<0.05) in bacterial adhesion to silicone and acrylic after precontact with the conditioning substances. No statistical differences (P>0.05) were found between the extent of adhesion on silicone coupons precontacted either with heparin or gentian violet for each of the strains tested. On acrylic, heparin was more efficient (P<0.001) in reducing S. epidermidis IE186 adhesion than was gentian violet (85% and 53% reductions, respectively). Therefore, immersion of acrylic and silicone in heparin or gentian violet may constitute a simple and effective method by which to reduce S. epidermidis adhesion to medical devices.

The role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance

The aim of this study was to determine the role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance. The adherence of S. epidermidis 1457 and the mutant defective in PIA production (1457-M10) to urinary epithelium and endothelium was estimated by colony counting. Minimum bactericidal concentration and mean reduction of cellular activity (XTT) following antibiotic exposure was determined for planktonic and adhered bacteria. S. epidermidis 1457 adhered to a greater extent to both cells than the mutant strain. The adhered strains had a significantly higher antimicrobial tolerance than their planktonic counterparts. The mutant strain was, in general, the most susceptible to the antibiotics assayed. In conclusion, PIA may influence S. epidermidis adherence to host tissues and their antimicrobial susceptibility. Initial adhesion may be the main step for the acquisition of resistance in S. epidermidis.

Effect of farnesol on Candida dubliniensis morphogenesis

AIMS

Cell-cell signalling in Candida albicans is a known phenomenon and farnesol was identified as a quorum sensing molecule determining the yeast morphology. The aim of this work was to verify if farnesol had a similar effect on Candida dubliniensis, highlighting the effect of farnesol on Candida spp. morphogenesis.

METHODS AND RESULTS

Two different strains of C. dubliniensis and one of C. albicans were grown both in RPMI 1640 and in serum in the presence of absence of farnesol. At 150 micromol l(-1) farnesol the growth rate of both Candida species was not affected. On the contrary, farnesol inhibited hyphae and pseudohyphae formation in C. dubliniensis.

CONCLUSION

Farnesol seems to mediate cell morphology in both Candida species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The effect of farnesol on C. dubliniensis morphology was not reported previously.

Extraction of exopolymers from biofilms: the protective effect of glutaraldehyde

The extraction of the exopolymeric matrix is a prerequisite to properly assessing the composition of the biofilm. Several extraction methods have already been developed, however, no universal method has yet been adopted because the compromise between high yields of extraction and minimum cell lysis is difficult to establish. In fact, most of the extraction methods promote leakage of intracellular material. The most common extraction methods, Dowex resin and sonication, were assayed in biofilms of Pseudomonas fluorescens and Alcaligenes denitrificans submitted to a pre-treatment with glutaraldehyde (GTA). The assessment of ATP released after extraction was used as a criterion of cell lysis. The results showed that GTA is a protective agent against cell lysis. The pre-treatment with GTA is particularly useful combined with sonication.

[Congenital malformations of the upper limb. General considerations]

The authors develop same general considerations about history, embryology, classification and treatment of congenital upper limb anomalies. They review 62 clinical cases of operated patients in Unit Plastic and Reconstructive Surgery of Santa Maria Hospital and show same cases.

[The vertebro-thoracic syndrome]

The authors report a clinical case of outlet syndrome, the only one diagnosed in the outpatient clinic of the Plastic Surgery Department, Santa Maria Hospital, Lisbon, in the last 25 years. The principal etiologic factors, clinical aspects, diagnosis and treatment are reviewed.

[Evolution of the detection of interventricular septal defect]

From 24.10.1969 to 31.12.1986, seventeen years, 1274 infants and children with proven isolated ventricular septal defect were observed and followed in Pediatric Cardiology of Santa Marta Hospital. There were 659 males and 615 females, ranging from 3 days to 12 years, born in portuguese territory and without syndromes. As early detection and referring is crucial to prevent pulmonary vascular disease with fixed pulmonary arterial resistance, the annual variation of the referring age was studied. The results improved since 1972 with a steady faster improvement during the last 7 years of the study.

Ribosomal DNA spacer probes for yeast identification: studies in the genus Metschnikowia

To test whether DNA probes derived from ribosomal DNA spacer sequences are suitable for rapid and species-specific yeast identification, a pilot study was undertaken. A 7.7 kb entire ribosomal DNA unit of the type strain of Metschnikowia reukaufii was isolated, cloned and mapped. A 0.65 kb BamHI-HpaI fragment containing non-transcribed spacer sequences was amplified and selected for testing as a 32P hybridization probe with total DNA from the type strains of M. reukaufii, M. pulcherrima, M. lunata, M. bicuspidata, M. australis, M. zobellii, M. krissii, five other strains identified as M. reukaufii and strains of Schizosaccharomyces pombe, Hansenula canadensis, Saccharomyces cerevisiae and Yarrowia lipolytica. The probe hybridized exclusively with DNA from the type strain and four other strains of M. reukaufii. DNA from one strain labelled M. reukaufii did not hybridize with the probe. Subsequent % G + C comparison and DNA-DNA reassociation with the type strain revealed that the non-hybridizing strain does not belong to the species M. reukaufii.

Child survival, height for age and household characteristics in Brazil

"The impact of household characteristics on child survival and height, conditional on age, is examined using household survey data from Brazil. Parental education is found to have a very strong positive effect on both outcomes and this is robust to the inclusion of household income and also parental heights, which partly proxy for unobserved family background characteristics. We find that income effects are significant and positive for child survival but insignificant for for child height although the latter depends on identification assumptions. Parental height has a large positive impact on child height and on survival rates even after controlling for all other observable characteristics."