Experimental Yellow Fever in the Squirrel Monkey (Saimiri spp.): Hematological, Biochemical, and Immunological Findings.

Between 2016 and 2018, Brazil experienced the largest sylvatic epidemic of yellow fever virus (YFV). Despite to the magnitude and rapid spread of the epidemic, little is known about YFV dispersion. The study evaluated whether the squirrel monkey is a good model for yellow fever (YF) studies. Methods: Ten animals were infected with 1 × 106 PFU/mL of YFV, with one negative control. Blood samples were collected daily during the first 7 days and at 10, 20 and 30 days post infection (dpi) for detection of viral load and cytokines by RT-qPCR; measurements of AST, ALT, urea and creatinine were taken; IgM/IgG antibodies were detected by ELISA, and hemagglutination inhibition and neutralization tests were performed. The animals exhibited fever, flushed appearance, vomiting and petechiae, and one animal died. Viremia was detected between 1 and 10 dpi, and IgM/IgG antibodies appeared between 4 and 30 dpi. The levels of AST, ALT and urea increased. The immune responses were characterized by expression of S100 and CD11b cells; endothelial markers (VCAM-1, ICAM-1 and VLA-4), cell death and stress (Lysozyme and iNOS); and pro-inflammatory cytokines (IL-8, TNF-α, and IFN-γ) and anti-inflammatory cytokines (IL-10 and TGF-ß). The squirrel monkeys showed changes similar to those described in humans with YF, and are a good experimental model for the study of YF.

A case of fulminant respiratory diphtheria in a 24-year-old Afghan refugee in Austria in May 2022: a case report.

PURPOSE: Raising awareness of respiratory diphtheria and for the importance of early antitoxin administration. METHODS: Report of a case of fulminant, imported respiratory diphtheria in an otherwise healthy 24-year-old Afghan refugee in Austria in May 2022. RESULT: This was the first case of respiratory diphtheria in Austria since 1993. Diphtheria antitoxin was administered at an already progressed disease stage. This delay contributed to a fulminant disease course with multiorgan failure and death. CONCLUSION: In high-income countries with low case numbers, awareness of respiratory diphtheria and for the importance of early antitoxin administration must be raised.

Serological and Molecular Evidence of the Circulation of the Venezuelan Equine Encephalitis Virus Subtype IIIA in Humans, Wild Vertebrates and Mosquitos in the Brazilian Amazon.

Understanding the interaction between viruses and ecosystems in areas with or without anthropic interference can contribute to the organization of public health services, as well as prevention and disease control. An arbovirus survey was conducted at Caxiuanã National Forest, Pará, Brazil, where 632 local residents, 338 vertebrates and 15,774 pools of hematophagous arthropods were investigated. Neutralization antibodies of the Venezuelan Equine Encephalitis virus, subtype IIIA, Mucambo virus (MUCV) were detected in 57.3% and 61.5% of humans and wild vertebrates, respectively; in addition, genomic fragments of MUCV were detected in pool of Uranotaenia (Ura.) geometrica. The obtained data suggest an enzootic circulation of MUCV in the area. Understanding the circulation of endemic and neglected arboviruses, such as MUCV, represents an important health problem for the local residents and for the people living in the nearby urban centers.

Absence of Anti-RBD Antibodies in SARS-CoV-2 Infected or Naive Individuals Prior to Vaccination with CoronaVac Leads to Short Protection of Only Four Months Duration.

The COVID-19 pandemic is the biggest public health threat facing the world today. Multiple vaccines have been approved; however, the emergence of viral variants such as the recent Omicron raises the possibility of booster doses to achieve adequate protection. In Brazil, the CoronaVac (Sinovac, Beijing, China) vaccine was used; however, it is important to assess the immune response to this vaccine over time. This study aimed to monitor the anti-SARS-CoV-2 antibody responses in those immunized with CoronaVac and SARS-CoV-2 infected individuals. Samples were collected between August 2020 and August 2021. Within the vaccinated cohort, some individuals had a history of infection by SARS-CoV-2 prior to immunization, while others did not. We analyzed RBD-specific and neutralizing-antibodies. Anti-RBD antibodies were detected in both cohorts, with a peak between 45-90 days post infection or vaccination, followed by a steady decline over time. In those with a previous history of COVID-19, a higher, longer, more persistent response was observed. This trend was mirrored in the neutralization assays, where infection, followed by immunization, resulted in higher, longer lasting responses which were conditioned on the presence of levels of RBD antibodies right before the vaccination. This supports the necessity of booster doses of CoronaVac in due course to prevent serious disease.

All-in-fiber SESAM based comb oscillator with an intra-cavity electro-optic modulator for coherent high bandwidth stabilization.

We demonstrate the stabilization of an all-in-fiber polarization maintaining semi-conductor saturable absorber mirror (SESAM) mode locked frequency comb oscillator with an intra-cavity waveguide electro-optic phase modulator (EOM) to a narrow linewidth HeNe laser over 46 hours. The high feedback bandwidth of the EOM allows a coherent optical lock with an in-loop integrated phase noise of 1.12 rad (integrated from 10 Hz to 3 MHz) from the carrier signal. No piezo fiber stretcher was required to guarantee long-term stabilization, preventing mechanical degradation of the optical fibers and enabling a long lifetime of the oscillator. As an application a hybrid stabilization scheme is presented, where a comb tooth is phase locked to a longitudinal mode of the large ring laser "G" located at the Geodatic Observatory Wettzell. The hybrid stabilization scheme describes the optical lock of the frequency comb to the G laser and the simultaneous compensation of the ring laser frequency drift by comparing the comb repetition rate against an active H-maser reference. In this context the ring laser reached a fractional Allan deviation of 5 · 10-16 at an integration time of 16384 s.

Hearing Preservation after Cochlear Implantation: UNICAMP Outcomes.

Background. Electric-acoustic stimulation (EAS) is an excellent choice for people with residual hearing in low frequencies but not high frequencies and who derive insufficient benefit from hearing aids. For EAS to be effective, subjects' residual hearing must be preserved during cochlear implant (CI) surgery. Methods. We implanted 6 subjects with a CI. We used a special surgical technique and an electrode designed to be atraumatic. Subjects' rates of residual hearing preservation were measured 3 times postoperatively, lastly after at least a year of implant experience. Subjects' aided speech perception was tested pre- and postoperatively with a sentence test in quiet. Subjects' subjective responses assessed after a year of EAS or CI experience. Results. 4 subjects had total or partial residual hearing preservation; 2 subjects had total residual hearing loss. All subjects' hearing and speech perception benefited from cochlear implantation. CI diminished or eliminated tinnitus in all 4 subjects who had it preoperatively. 5 subjects reported great satisfaction with their new device. Conclusions. When we have more experience with our surgical technique we are confident we will be able to report increased rates of residual hearing preservation. Hopefully, our study will raise the profile of EAS in Brazil and Latin/South America.

Optimization, refinement and reduction of murine in vivo experiments to assess therapeutic approaches for haemophilia A.

The tail cut bleeding model (CUT) is routinely used in factor VIII-deficient mice to assess pharmacodynamic effects of therapeutic strategies for haemophilia A. Results from this model are highly variable, many modifications to the model are reported and at times the animals' wellbeing may be compromised by recording survival as an endpoint. We therefore investigated if the ferric chloride carotid occlusion model (COM) used for thrombosis research can be applied to enhance data quality and animal welfare in haemophilia A research. Relative dose effects and relative dose variations were calculated for the CUT and COM. The requisite sample sizes were estimated and the importance of survival rates to assess rebleeds during recovery was evaluated by correlating initial blood loss to mortality. Relative dose effects increased with higher doses in both models. The COM was more sensitive at lower doses than the CUT, had up to 82% less variation across doses and clearly showed superior accuracy. Only 5% of the sample size required for the CUT would be needed to establish non-inferiority between a specific therapeutic dose in haemophilia A mice and healthy wild-type animals. A strong statistically significant correlation was found between initial blood loss and mortality within 24 h. Our findings clearly suggest that the COM is a valid tool for assessing haemophilia A treatment in vivo. The highly reproducible data means that significantly fewer animals are required and a more humane endpoint can be used by directly assessing clot stability instead of survival rate.

Massaging over the greater occipital nerve reduces the intensity of migraine attacks: evidence for inhibitory trigemino-cervical convergence mechanisms.

Activation of the trigemino-cervical system constitutes one of the first steps in the genesis of migraine. The objective of this study was to confirm the presence of trigemino-cervical convergence mechanisms and to establish whether such mechanisms may also be of inhibitory origin. We describe a case of a 39-years-old woman suffering from episodic migraine who showed a significant improvement in her frontal headache during migraine attacks if the greater occipital nerve territory was massaged after the appearance of static mechanical allodynia (cortical sensitization). We review trigemino-cervical convergence and diffuse nociceptive inhibitory control (DNIC) mechanisms and suggest that the convergence mechanisms are not only excitatory but also inhibitory.

Massaging over the greater occipital nerve reduces the intensity of migraine attacks: evidence for inhibitory trigemino-cervical convergence mechanisms

Activation of the trigemino-cervical system constitutes one of the first steps in the genesis of migraine. The objective of this study was to confirm the presence of trigemino-cervical convergence mechanisms and to establish whether such mechanisms may also be of inhibitory origin. We describe a case of a 39-years-old woman suffering from episodic migraine who showed a significant improvement in her frontal headache during migraine attacks if the greater occipital nerve territory was massaged after the appearance of static mechanical allodynia (cortical sensitization). We review trigemino-cervical convergence and diffuse nociceptive inhibitory control (DNIC) mechanisms and suggest that the convergence mechanisms are not only excitatory but also inhibitory.

Ativação do sistema trigemino-cervical constitui um dos primeiros passos na gênese da crise de migrânea. O objetivo do estudo foi descrever um caso clínico que sugere a existência de mecanismos de convergência trigemino-cervical (CTC) e que esses possam ser do tipo inibitórios. Nós descrevemos o caso de mulher de 39 anos com migrânea episódica que mostrou significante melhora em sua cefaléia frontal durante suas crises quando realizava massagem sobre o território do nervo occipital maior ipsilateral a dor. A melhora clínica só ocorria quando a paciente apresentava alodinia mecânica estática (sensibilização cortical). Neste estudo nós revisamos os conceitos de CTC e de mecanismos de controle inibitório nociceptivo difuso (MCIN), sugerindo que este último é um elemento comprobatório da presença de CTC do tipo inibitório durante as crises de migrânea.

Purification, characterization and biological evaluation of recombinant leech-derived tryptase inhibitor (rLDTI) expressed at high level in the yeast Saccharomyces cerevisiae.

An efficient expression/purification procedure has been developed which allows the production of pure, biologically active recombinant leech-derived tryptase inhibitor (rLDTI), originally found in the leech Hirudo medicinalis. The gene for LDTI was generated synthetically from three overlapping oligonucleotides by PCR synthesis. LDTI was expressed in the yeast Saccharomyces cerevisiae under the control of the copper-inducible CUP1 promoter and fused to the invertase signal sequence (SUC2). The entire expression cassette was inserted into the yeast high-copy vector pDP34. Appropriate host strains transformed with the expression plasmid secreted rLDTI into the medium upon copper addition. Proteinchemical analysis of the secreted rLDTI revealed exclusively inhibitor with the correct N-terminal sequence. Up to 60% of the rLDTI, however, appeared to be modified by glycosylation and the unglycosylated material showed heterogeneity at the C-terminus. Besides full-length rLDTI, truncated rLDTI species lacking either the terminal Asn46 or in addition the penultimate Leu45 were isolated. The C-terminally truncated variants were eliminated using a S. cerevisiae host strain disrupted in the structural genes of carboxypeptidases yscY and ysca, thus identifying these proteases as being responsible for the degradation of rLDTI. Mature rLDTI was purified in high yields from the culture supernatant of the carboxypeptidase-deficient yeast strain by cation-exchange chromatography and reverse-phase HPLC. The recombinant protein is at least 98% pure, based on HPLC and capillary electrophoresis, and is fully biologically active. Structural identity with the authentic leech protein was confirmed by sequence analysis and molecular-mass determination. The purified protein was tested for its ability to inhibit tryptase and trypsin in vitro and to interfere with the tryptase-induced proliferation of human fibroblasts and keratinocytes. Recombinant LDTI appears to be as potent as the authentic leech protein, exhibiting Ki-values of approximately 1.5 nM and approximately 1.6 nM against human tryptase and bovine trypsin, respectively. The tryptase-induced proliferation of human fibroblasts and keratinocytes was inhibited with half-maximum values of approximately 0.1 nM and approximately 1 nM, respectively. The availability of the recombinant material will allow evaluation of the concept of tryptase inhibition in various disease models and to test the therapeutic potential of LDTI in mast-cell-related disorders.

Emergency mechanical ventilation at moderate altitude.

Portable emergency ventilators are commonly used in the prehospital setting in the transport of critically ill patients in hypobaric environments. The aim of our trial was to evaluate the influence on minute ventilation and blood gas analysis of moderate altitude (3000 m) compared to 171 m in healthy volunteers during mechanical ventilation with the Draeger Oxylog ventilator. At 3000 m, the delivered minute volume increased by 9.8% in the air mix mode and by 14.6% in the no air mix mode. PaO2 at 3000 m altitude decreased by 33.3% in the air mix mode, and no statistical change was observed in the no air mix mode. PaCO2 at 3000 m altitude decreased by 9.0% in the air mix mode and by 12.8% in the no air mix mode. These changes are of sufficient magnitude and importance to require monitoring of minute volume to prevent barotrauma or volume-related trauma and to monitor oxygenation by pulse oximetry during emergency mechanical ventilation at moderate altitude.

An investigation on the role of vacuolar-type proton pumps and luminal acidity in calcium sequestration by nonmitochondrial and inositol-1,4,5-trisphosphate-sensitive intracellular calcium stores in clonal insulin-secreting cells.

To test whether in RINm5F rat insulinoma cells luminal acidity and the activity of a vacuolar-type proton pump are involved in calcium sequestration by intracellular calcium stores sensitive to inositol 1,4,5-trisphosphate (InsP3) we examined the effects of various proton-conducting ionophores and ammonium chloride, and of bafilomycin, a specific inhibitor of vacuolar proton pumps, on this parameter. Bafilomycin in concentrations up to 1 microM did not affect calcium sequestration by nonmitochondrial, InsP3-sensitive stores at all; 50 microM carbonylcyanide m-chlorophenylhydrazone, 50 microM monensin and 30 mM NH4Cl, which are diverse ways to dissipate transmembrane pH gradients, did not inhibit calcium sequestration. This argues against signficant involvement of internal acidity and vacuolar proton pumps in calcium sequestration by InsP3-sensitive stores in RINm5F cells. The proton-potassium-exchanging ionophore nigericin (20-100 microM), however, inhibited calcium sequestration by nonmitochondrial and InsP3-sensitive stores. This effect was dependent on the presence of potassium and could be reversed by inclusion of carbonylcyanide m-chlorophenylhydrazone or acetate in the incubation medium. Thus, the inhibitory effect of nigericin appears to be based on proton extrusion coupled to potassium influx across the membrane of calcium stores in RINm5F cells, creating an internal alkalinization of these stores. The effect of nigericin implies the continuous maintenance of an outside-to-inside potassium concentration gradient by nonmitochondrial calcium stores in RINm5F cells. This feature will be of potential interest in the identification of InsP3-sensitive calcium-storing organelles.

[Therapeutic drugs, illicit poisons and environmental chemicals in breast milk--assessing the risk]. / Medikamente, Suchtgifte und Umweltchemikalien in der Muttermilch--Risikobeurteilung.

Our knowledge about the transfer of drugs and environmental chemicals into breast milk has increased in the last years. This review is mainly based on recently published literature and focuses on all drugs and environmental substances with documented effects on lactation and the nursing infant. Our aim is to provide brief information for physicians who are counseling breastfeeding mothers.