Clinicopathological features, MCPyV status and outcomes of Merkel cell carcinoma in solid-organ transplant recipients: a retrospective, multicentre cohort study.

BACKGROUND: The proportion of Merkel cell carcinomas (MCCs) in solid-organ transplant recipients (SOTR) harbouring Merkel cell polyomavirus (MCPyV) is unknown, as are factors affecting their outcomes. OBJECTIVE: To describe clinicopathological features of MCC in SOTR, investigate the tumoral MCPyV-status and identify factors associated with tumour outcomes. METHODS: Retrospective, international, cohort-study. MCPyV-status was investigated by immunohistochemistry and polymerase chain reaction. RESULTS: A total of 30 SOTR and 44 consecutive immunocompetent patients with MCC were enrolled. SOTR were younger at diagnosis (69 vs. 78 years, P < 0.001). Thirty-three percent of SOTR MCCs were MCPyV-positive vs. 91% of immunocompetent MCCs (P = 0.001). Solid-organ transplantation was associated with an increased cumulative incidence of progression (SHR: 3.35 [1.57-7.14], P = 0.002), MCC-specific mortality (SHR: 2.55 [1.07-6.06], P = 0.034) and overall mortality (HR: 3.26 [1.54-6.9], P = 0.002). MCPyV-positivity and switching to an mTOR inhibitor (mTORi) after MCC diagnosis were associated with an increased incidence of progression (SHR: 4.3 [1.5-13], P = 0.008 and SHR: 3.6 [1.1-12], P = 0.032 respectively) in SOTR. LIMITATIONS: Retrospective design and heterogeneity of SOTR cohort. CONCLUSIONS: MCPyV appears to play a less prominent role in the aetiopathogenesis of MCC in SOTR. SOTR have a worse prognosis than their immunocompetent counterparts and switching to an mTORi after the diagnosis of MCC does not improve progression.

Lectins as antimicrobial agents.

The resistance of micro-organisms to antimicrobial agents has been a challenge to treat animal and human infections, and for environmental control. Lectins are natural proteins and some are potent antimicrobials through binding to carbohydrates on microbial surfaces. Oligomerization state of lectins can influence their biological activity and maximum binding capacity; the association among lectin polypeptide chains can alter the carbohydrate-lectin binding dissociation rate constants. Antimicrobial mechanisms of lectins include the pore formation ability, followed by changes in the cell permeability and latter, indicates interactions with the bacterial cell wall components. In addition, the antifungal activity of lectins is associated with the chitin-binding property, resulting in the disintegration of the cell wall or the arrest of de novo synthesis from the cell wall during fungal development or division. Quorum sensing is a cell-to-cell communication process that allows interspecies and interkingdom signalling which coordinate virulence genes; antiquorum-sensing therapies are described for animal and plant lectins. This review article, among other approaches, evaluates lectins as antimicrobials.

Establishment and cryptic transmission of Zika virus in Brazil and the Americas.

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

Interleukin-10 and tumour necrosis factor-alpha serum levels in chronic Chagas disease patients.

In Chagas disease, chronically infected individuals may be asymptomatic or may present cardiac or digestive complications, and it is well known that the human immune response is related to different clinical manifestations. Different patterns of cytokine levels have been previously described in different clinical forms of this disease, but contradictory results are reported. Our aim was to evaluate the serum levels of interleukin-10 and tumour necrosis factor-alpha in patients with asymptomatic and cardiac Chagas disease. The serum interleukin-10 levels in patients with cardiomyopathy were higher than those in asymptomatic patients, mainly in those without heart enlargement. Although no significant difference was observed in serum tumour necrosis factor-alpha levels among the patients, we found that cardiac patients also present high levels of this cytokine, largely those with heart dilatation. Therefore, these cytokines play an important role in chronic Chagas disease cardiomyopathy. Follow-up investigations of these and other cytokines in patients with chronic Chagas disease need to be conducted to improve the understanding of the immunopathology of this disease.

The role of the superior colliculus in predatory hunting.

Combining the results of behavioral, neuronal immediate early gene activation, lesion and neuroanatomical experiments, we have presently investigated the role of the superior colliculus (SC) in predatory hunting. First, we have shown that insect hunting is associated with a characteristic large increase in Fos expression in the lateral part of the intermediate gray layer of the SC (SCig). Next, we have shown that animals with bilateral NMDA lesions of the lateral parts of the SC presented a significant delay in starting to chase the prey and longer periods engaged in other activities than predatory hunting. They also showed a clear deficit to orient themselves toward the moving prey and lost the stereotyped sequence of actions seen for capturing, holding and killing the prey. Our Phaseolus vulgaris-leucoagglutinin analysis revealed that the lateral SCig, besides providing the well-documented descending crossed pathway to premotor sites in brainstem and spinal cord, projects to a number of midbrain and diencephalic sites likely to influence key functions in the context of the predatory behavior, such as general levels of arousal, motivational level to hunt or forage, behavioral planning, appropriate selection of the basal ganglia motor plan to hunt, and motor output of the primary motor cortex. In contrast to the lateral SC lesions, medial SC lesions produced a small deficit in predatory hunting, and compared to what we have seen for the lateral SCig, the medial SCig has a very limited set of projections to thalamic sites related to the control of motor planning or motor output, and provides conspicuous inputs to brainstem sites involved in organizing a wide range of anti-predatory defensive responses. Overall, the present results served to clarify how the different functional domains in the SC may mediate the decision to pursue and hunt a prey or escape from a predator.

Clinical aspects of epidermodysplasia verruciformis.

Thirteen patients with epidermodysplasia verruciformis (EV) were studied over a period of 7 years. EV is a rare genodermatosis characterized by a generalized infection with a specific group of human papilloma virus (HPV) and a propensity for developing skin malignant tumours in 30%-50% of patients. The diagnosis of EV was confirmed by histopathological and immunohistochemical findings. Three of our patients had the benign form of EV, which is characterized by monomorphous lesions and no malignant changes, whereas 10 had the malignant form, which is characterized by polymorphic lesions and development of cutaneous malignant tumours. All EV patients with the malignant form developed multiple skin tumours (77%). They started to appear at age 20, predominantly on the forehead (50%). Most were squamous cell carcinoma, extremely aggressive and invasive, which provoked metastasis and death in two patients.

[Anatomic reconstruction of native coronary arteries and vein graft with less shortening wallstent]. / Reconstrução anatômica das artérias coronárias nativas e das pontes de safena utilizando less shortening wallstent.

PURPOSE: To evaluate the advantage of the wallstent in the treatment of long or multiple lesions. METHODS: Thirty eight patients with mean age 66 years underwent wallstent implantation. Fourteen had lesions in the left anterior descending, 12 in the right coronary, nine in the circumflex and four in a vein graft. The technique for implantation requires an accurate quantification of the vessel diameter, because the chosen stent should be 1.5 mm larger than the target vessel. A new technique using additional inflations with high pressure balloons was applied. RESULTS: Successful implantation occurred in 95%. We did not have success in two patients. One of them due to damage in the stent and the other to unsuccessful liberation. Both patients were submitted to conventional angioplasty without complications. CONCLUSION: The wallstent implantation can be successfully performed with high success rate, but late angiographic results still demand further studies.

A flow-cell optosensor for lead based on immobilized dithizone.

Dithizone immobilized on XAD-4 resin has been studied as a sensor element of an optical sensor for lead using a flow-cell. Using this arrangement, lead in solution has been determined in the concentration range 1 x 10(-5)-3 x 10(-7)M with a detection limit of 1 x 10(-8)M(i.e., 2 mug/l.). The standard deviation of the method for the measurement of lead at a concentration of 1 x 10(-6)M was found to be 7%. The response of the sensor was reproducible and can be regenerated using 0.01M hydrochloric acid followed by citrate-hydroxylamine solution.

[Relation of the major connector of a removable partial denture (RPD) with mandibular mucosal tissue; clinical case]. / Relação do conector maior de prótese parcial removível (PPR) com os tecidos mucosos mandibulares; caso clínico.

When the performance of removable partial prosthesis is analyzed, it can be seen that failures outnumber the successes. These failures, however, should not be imputed to the prostheses themselves, but rather to the fact that proper biomechanical principles were not observed in the planning of these devices. Each component of a prosthesis should be carefully planned in order to obtain maximum stability with respect to the supporting tissues. One of these principles is concevued to the relieve that must be established between major connectors and mandibular mucosae. It is important to remember that mandibular mucosae is fine, moveable, very sensitive and weak, so that this mucosae be considered very susceptible to mechanical aggression. In this work the authors emphasize the necessity of relieve in the mandibular major connector in order not to pressure the investing tissues. Otherwise serious periodontal damage can occur.

Determination of calcium and magnesium in limestone and dolomite by enthalpimetric flow-injection analysis.

A flow-enthalpimetric method for the determination of calcium and magnesium in limestone and dolomite is described. Calcium is determined by measuring the heat evolved from the substitution reaction with Mg-EDTA. The amount of magnesium is calculated from the calcium content and the enthalpimetric signal for the reaction of the sample solution with disodium-EDTA, which gives the total concentration of calcium and magnesium. Analysis of reference materials and other samples indicates an error not exceeding 0.3% of CaO and MgO, and a sampling rate of 100 samples per hour.

[Re-evaluation of clinical and electroencephalographical criteria of brain death determination in the child]. / Reavaliação dos critérios clínicos e eletrencefalográficos de determinação da morte cerebral na criança.

A case is reported in which there was a return of the electroencephalogram after a period of more than 36 hours of electrocerebral silence. Electroencephalographic technique and instrumentation were in accordance with the recommendations of Silverman, Saunders, Schwab and Masland . The possibilities of hypothermia or drug overdosage, known to reversibly depress the electroencephalogram, were excluded in the related case. The return of EEG activity was preceded by improvement in neurological status. It is concluded that criteria accepted for the determination of brain death in adults should not be valid for children.

Determination of water in ethanol and acetone by direct injection enthalpimetry based on the heat of dilution.

Two analytical procedures based on the magnitude of the heat of dilution and direct injection enthalpimetry have been developed for determination of water in ethanol and acetone. The results obtained by means of the heat of dilution were compared with the values given by pycnometry, and gave a relative difference in the range 0.2-3%. The precision depends on the slope of the calibration curve, which varies with the procedure and the concentration of the sample.

Determination of carbohydrates by direct injection enthalpimetry.

An analytical method for the determination of carbohydrates is described, which is based on the enthalpimetric signal obtained at the beginning of the reaction with periodate. The apparatus is described and relevant aspects of the procedure are discussed. Single carbohydrates can be determined in a few minutes with a precision of 1%. Analysis of mixtures of glucose and fructose is reported.