Humoral response in Leishmaniasis

Leishmaniasis presents different types of clinical manifestations that can be divided into cutaneous leishmaniasis and visceral leishmaniasis. The host's immune system, associated with genetic and nutritional factors, is strongly involved in the evolution of the disease or parasite escape. Humoral immunity is characterized by the production of antibodies capable of promoting neutralization, opsonization, and activation of the complement system. In this scenario, B lymphocytes produce antibodies that play an important role in Leishmania infection although neglected for a long time. Thus, relevant aspects in the establishment of Leishmania infection will be addressed, highlighting the importance of humoral immunity during the entire process of Leishmania infection.

ITER collective Thomson scattering-Preparing to diagnose fusion-born alpha particles (invited)

The ITER Collective Thomson scattering (CTS) diagnostic will measure the dynamics of fusion-born alpha particles in the burning ITER plasma by scattering a 1 MW 60 GHz gyrotron beam off fast-ion induced fluctuations in the plasma. The diagnostic will have seven measurement volumes across the ITER cross section and will resolve the alpha particle energies in the range from 300 keV to 3.5 MeV; importantly, the CTS diagnostic is the only diagnostic capable of measuring confined alpha particles for energies below ∼1.7 MeV and will also be sensitive to the other fast-ion populations. The temporal resolution is 100 ms, allowing the capture of dynamics on that timescale, and the typical spatial resolution is 10-50 cm. The development and design of the in-vessel and primary parts of the CTS diagnostic has been completed. This marks the beginning of a new phase of preparation to maximize the scientific benefit of the diagnostic, e.g., by investigating the capability to contribute to the determination of the fuel-ion ratio and the bulk ion temperature as well as integrating data analysis with other fast-ion and bulk-ion diagnostics.

Time-dependent decay of detectable antibodies against SARS-CoV-2: A comparison of ELISA with two batches of a lateral-flow test

BACKGROUND

Large-scale epidemiological studies of seroprevalence of antibodies against SARS-CoV-2 often rely on point-of-care tests that provide immediate results to participants. Yet, little is known on how long rapid tests remain positive after the COVID-19 episode, or how much variability exists across different brands and even among batches of the same test.

METHODS

In November 2020, we assessed the sensitivity of three tests applied to 133 individuals with a previous positive PCR result between April and October. All subjects provided finger prick blood samples for two batches (A and B) of the Wondfo lateral-flow IgG/IgM test, and dried blood spot samples for the S-UFRJ ELISA test.

RESULTS

Overall sensitivity levels were 92.5% (95% CI 86.6-96.3), 63.2% (95% CI 54.4-71.4) and 33.8% (95% CI 25.9-42.5) for the S-UFRJ test, Wondfo A and Wondfo B tests, respectively. There was no evidence of a decline in the positivity of S-UFRJ with time since the diagnosis, but the two Wondfo batches showed sharp reductions to as low as 41.9% and 19.4%, respectively, for subjects with a positive PCR in June or earlier. Positive results for batch B of the rapid test were 35% to 54% lower than for batch A at any given month of diagnosis.

INTERPRETATION

Whereas the ELISA test showed high sensitivity and stability of results over the five months of the study, both batches of the rapid test showed substantial declines, with one of the batches consistently showing lower sensitivity levels than the other. ELISA tests based on dried-blood spots are an inexpensive alternative to rapid lateral-flow tests in large-scale epidemiological studies.

FUNDING

The study was funded by the "Todos Pela Saúde" initiative, Instituto Serrapilheira, Brazilian Ministry of Health, Brazilian Collective Health Association (ABRASCO) and the JBS S.A. initiative 'Fazer o Bem Faz Bem'.

Organizing pneumonia revisited: insights and uncertainties from a series of 67 patients

Background: Organizing pneumonia (OP) is classified as an acute/subacute pneumonia according to the American Thoracic Society/European Respiratory Society statement (2013 update). Although its clinical presentation, radiologic and histologic features are well established, data on the relevance of potential causes, corticosteroid doses and length, or management of relapses are based on heterogeneous series of patients. Objectives: The aims of this study were to describe clinical presentation, diagnosis and treatment of OP, explore potential causes, discuss strategies for managing relapses, and analyze prognostic factors. We also discuss our findings in relation to relevant data in the literature. Methods: We performed a cross-sectional study of all patients diagnosed with OP at a tertiary referral center in northern Portugal between 2008 and 2015. Results: Sixty-seven patients were diagnosed with OP over the 7-year study period. Dyspnea and cough were the most common presenting symptoms and approximately 30% of patients were hospitalized at the time of diagnosis. Approximately half of the patients were receiving drugs described as potential causes of OP. Microorganisms were isolated in approximately one-third of patients. Other potential causes identified were hematologic disorders, neoplasms, connective tissue diseases, myelodysplastic syndromes, immunodeficiencies, radiotherapy, and bird exposure. Cryptogenic OP was diagnosed in just 16 patients (23.8%). Corticosteroids were the most common treatment and 11 patients (16.4%) experienced relapse. Conclusions: The findings for this series of patients confirm the extreme variability of the contexts in which OP can occur and suggest that rather than a distinct, homogeneous clinicopathologic entity, OP is a non-specific reaction whose outcomes are dependent on the cause. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 129-138).

Breeding system and factors limiting fruit production in the nectarless orchid Broughtonia lindenii

Low fruit set values in most orchids (especially epiphytic and tropical species) are normally thought to be the consequence of pollination constraints and limited resources. In particular, pollination constraints are modulated by pollinator visitation rates, pollinator visitation behaviour (promoting crossing or selfing), the type and number of pollinia deposited on stigmas (in the case of orchids with subequal pollinia) and the amount of pollen loaded per inflorescence. In order to assess to what extent these factors can affect fruit set in specific orchid-pollinator systems, the repercussions of some of these aspects on reproduction of Broughtonia lindenii were examined in a coastal population in western Cuba. The study focused on plant breeding system, importance of pollen load and type of pollinia on subsequent fruit and seed, limiting factors of seed production and interaction with pollinators. This species presents long-lasting flowers that senesce after all forms of effective visit. Pollinator dependence for fruit production was demonstrated, while hand-pollination experiments revealed self-compatibility and inbreeding depression at seed level. More pollinia on stigmas enhance the proportion of well-developed seeds. In contrast, the pollinia type used in pollination is not important for seed quality of fruits, suggesting that small pollinia are not rudimentary. Natural fruit set in two consecutive years was substantially affected by pollinator activity, and also by systematic depredatory activity of ants and a caterpillar. Considering that this orchid completely lacks nectar and that the local assemblage of pollinators and predators influenced its reproduction, a minor importance of resource constraints in this epiphyte (with long-lasting reserve structures) is confirmed at least for a short time.

Lymphogranuloma venereum serovar L2b in Portugal

Summary

Chlamydia trachomatis, serovar L2, is the causative agent of lymphogranuloma venereum (LGV), which during recent years has been responsible for various outbreaks reported among men who have sex with men (MSM) in Western Europe, America, Canada and Australia. Samples from nine patients with chronic proctitis, seen at a local hospital were sent to us for identification of C. trachomatis serovar L2. The presence of C. trachomatis serovar L DNA was identified by realtime polymerase chain reaction (PCR) in two patients. They both had high positive C. trachomatis antibody titres (≥ 10,000) and were found to be infected with serovar L2b by sequencing after amplification of the omp 1 gene by a nested PCR technique. These two individuals met the diagnostic criteria for LGV serovar L2b infection and, to our knowledge, these are the first cases described in Portugal.

Use of oral dimercaptosuccinic acid (succimer) in adult patients with inorganic lead poisoning

BACKGROUND

Chelation therapy has been used as a means of reducing the body burden of lead for five decades. Intravenous sodium calcium edetate has been the preferred agent, but there is increasing evidence that dimercaptosuccinic acid (DMSA) is also a potent chelator of lead.

METHODS

Oral DMSA 30 mg/kg/day was administered to adults with blood lead concentrations > or = 50 microg/dl. The impact of DMSA on urine lead excretion, on blood lead concentrations and on symptoms was observed. The incidence and severity of adverse effects was also recorded.

RESULTS

Thirty-five courses were given to 17 patients. DMSA significantly (P < 0.0001) increased urine lead excretion and significantly (P < 0.0001) reduced blood lead concentrations. Mean daily urine lead excretion exceeded the pre-treatment value by a median of 12-fold with wide variation in response (IQR 8.9-14.8, 95% CI 10.1-14.6). Pre-treatment blood lead concentrations correlated well with 5-day urine lead excretion. Headache, lethargy and constipation improved or resolved in over half the patients within the first 2 days of chelation. DMSA was generally well tolerated, but one course was discontinued due to a severe mucocutaneous reaction. There was a transient increase in alanine aminotransferase (ALT) activity during 14% of chelations. DMSA caused a significant increase in urine copper (P < 0.0001) and zinc (P < 0.05) excretion.

CONCLUSION

Oral DMSA 30 mg/kg/day is an effective antidote for lead poisoning, though there is a wide inter- and intra-individual variation in response.

Anorectal lymphogranuloma venereum: the first two confirmed cases in Portugal

We describe two cases of lymphogranuloma venereum (LGV) in men who have sex with men in Portugal in 2008. These first two confirmed cases of LGV L2b proctitis in Portugal highlight the need for an enhanced surveillance programme in Portugal.

Type 2B von Willebrand's disease due to Val1316Met mutation. Heterogeneity in the same sibship

An analysis was conducted in four members of the same family, two of whom had a history of severe bleeding associated with type 2B von Willebrand's disease (VWD) which, although found to be due to the same mutation, nevertheless exhibited different phenotype patterns in the two subjects involved. Von Willebrand's factor (VWF) multimers were assayed with high- and low-resolution sodium dodecyl sulfate (SDS) agarose gels. The patients were studied before and after intravenous administration of desmopressin (DDAVP) at doses of 0.4 microg/kg body weight. Automatic sequencing techniques were used to analyze VWF gene exon 28. The propositus presented with mild basal thrombocytopenia with ristocetin-induced platelet aggregation (RIPA) at low concentrations of ristocetin. He had a very prolonged bleeding time (BT), and his plasma VWF was found to be lacking in large and intermediate multimers. Thrombocytopenia was observed to intensify transiently after the administration of DDAVP. The propositus' mother, in contrast, presented reduced RIPA while in a basal state, with only partial loss of the high molecular weight VWF multimers. Although she had a very prolonged BT, her platelet count was borderline. Transient correction of BT and a decrease in the platelet count were observed after administration of DDAVP and RIPA was observed at low concentrations of ristocetin. Exon 28 sequencing revealed a G4196A-->Val1316Met mutation in both patients. No other abnormality was detected within this exon. Val1316Met has been reported in type 2B VWD. In conclusion, in the family presented here, the phenotype pattern in one patient was typical of type 2B VWD, whereas the pattern in his mother was closer to type 2A VWD. After administration of DDAVP, however, a type 2B phenotype could be clearly attributed to both, indicating that this drug can be a useful tool for elucidating ambiguous phenotypes.

Heart disease and young adults: is prevention important?

The purpose of this study was to investigate whether prevention of heart disease was important to adolescents and young adults. To study this concept, 2 research questions were asked: (a) Are adolescents and young adults able to identify cardiac risk factors? (b) Is the prevention of coronary heart disease important to adolescents and young adults? A quantitative descriptive design was used. A convenience sample of 63 male and female participants from 2 music organizations participated. The age range of participants was 18 to 21 years old. The participants represented 19 states in the United States. Data were collected through a survey. Results were evaluated using descriptive statistical analysis. Findings demonstrate that adolescents and young adults have some knowledge of certain cardiac risk factors and preventive measures. Prevention is important to this population. Additional education is needed on significant risk factors identified on a low frequency. The results of this study are useful for health educators from a prevention perspective.

Alcohol and attempted suicide

This study investigates the prevalence of excessive drinking and alcohol-related problems amongst suicide attempts. It also compares the characteristics of attempted suicide by alcohol consumption group. Drinking histories were taken on 250 consecutive attempted suicides admitted to the West Midlands Poisons Unit. Fifty-one per cent of the men and 31% of the women drank more than the weekly limits recommended by the Health Education Council. Of the men, 22.5% drank more than 50 units of alcohol a week and 9.5% of the women drank more than 35 units of alcohol a week. Alcohol-related problems (social problems, alcohol dependence or physical illness) were present in 34% of men and 15.5% of women. These results show a greater incidence of alcohol misuse than previous studies on attempted suicide. This is probably because detailed alcohol histories were taken on all patients. Alcohol misuse is best treated before major alcohol-related problems develop. Those responsible for assessing cases of attempted suicide should be adept at detecting alcohol misuse and instituting appropriate management.

Experience with activated carbon-bead haemoperfusion columns in the treatment of severe drug intoxication. A preliminary report

Five patients who were severely poisoned with hypnotic drugs, paracetamol, or theophylline were treated by charcoal haemoperfusion. The device contained 160 g of activated carbon beads with a polyester coating. Four patients made a significant improvement; one subsequently died from a cerebral haemorrhage which had occurred prior to haemoperfusion. Platelet losses were minimal and no fibrinolysis was observed. No significant biochemical abnormality occurred as a result of haemoperfusion, although one patient, who presented with hypocalcaemia, required intravenous calcium throughout the procedure.

Haemoperfusion in 'late' paracetamol poisoning

1 Seven patients who presented to hospital later than 10 hours following an overdose of paracetamol were treated by charcoal haemoperfusion. 2 In all cases there was a rapid fall in the plasma paracetamol concentrations, although the total amounts of drug removed varied from 364.5 mg to 6699 mg. 3 One patient developed fulminant hepatic failure and died; the remainder recovered, sustaining only mild hepatic damage (maximum AST less than 1000 iu1(-1)). 4 Charcoal haemoperfusion may be effective in mitigating the severity of liver injury in those patients who are not eligible to receive specific antidotal therapy.