Subbasal corneal nerve damage in patients with bacterial keratitis: in vivo confocal microscopy study / Danos no plexo nervoso subbasal corneano em pacientes com ceratite bacteriana utilizando a microscopia confocal in vivo

ABSTRACT Purpose: To examine subbasal corneal nerve changes in patients with bacterial infectious keratitis using in vivo confocal microscopy. Methods: Thirteen patients (13 eyes) with unilateral bacterial keratitis and 12 healthy controls were prospectively enrolled in the study. In vivo confocal microscopy was performed in all the patients at 2 time points, in the acute phase of infectious keratitis and at 28 ± 0.6 months after resolution of the infection. Results: The subbasal nerve length was 5.15 ± 1.03 mm/mm2 during the acute phase of bacterial keratitis (compared with that of the controls: 19.02 ± 1.78 mm/mm2, p<0.05). Despite the significant corneal nerve regeneration over the interval of 28 months after the resolution of the infection, the nerve density was still significantly reduced as compared with that of the controls (9.73 ± 0.93 mm/mm2, p<0.05). Moreover, in vivo confocal microscopy images showed diffuse high-reflecting areas referring to the scar tissue areas with thin and tortuous nerve branches regenerating toward these areas. Conclusions: A partial corneal nerve regeneration of subbasal nerve plexus during the first 28 months after the acute phase of infectious keratitis was observed. Moreover, the regenerated nerves of the patients remained morphologically altered as compared with those of the healthy controls. These results may be relevant to the clinical follow-up and surgical planning for these patients.

RESUMO Objetivo: Relatar as alterações no plexo nervoso corneano subbasal em pacientes com ceratite infecciosa de origem bacteriana utilizando a microscopia confocal in vivo. Métodos: Treze olhos de 13 pacientes com ceratite bacteriana unilateral e 12 indivíduos saudáveis como grupo controle foram incluídos prospectivamente no estudo. A microscopia confocal in vivo foi realizada em todos os pacientes em 2 momentos: na fase aguda da ceratite infecciosa e após 28 ± 0,6 meses da resolução da infecção. Resultados: A densidade dos nervos no plexo subbasal foi de 5,15 ± 1,03 mm/mm2 na fase aguda da ceratite infecciosa (comparada com o grupo controle: 19,02 ± 1,78 mm/mm2, p<0,05). Apesar de significativa regeneração dos nervos corneanos ao longo de um intervalo de 28 meses após a resolução da infecção, a densidade dos nervos se manteve significativamente reduzida (9,73 ± 0,93 mm/mm2) quando comparada com o grupo controle (19,02 ± 1,78 mm/mm2, p<0,05). Além disso, as imagens obtidas com a microscopia confocal mostraram áreas de hiperreflectividade referente ao tecido corneano cicatricial com ramos de nervos, afinados e tortuosos, se regenerando nessas áreas. Conclusões: Foi observado regeneração parcial dos nervos do plexo corneano subbasal durante os primeiro 28 meses após a resolução da fase aguda da ceratite infecciosa. Além disso, os nervos corneanos regenerados se mantiveram morfologicamente alterados quando comparados ao grupo controle. Esses resultados podem ser relevantes para o acompanhamento clínico e planejamento cirúrgico desses pacientes.

Animal models and SARS-CoV-2-induced pulmonary and neurological injuries

Laboratory animals are essential mainly for experiments aiming to study pathogenesis and evaluate antivirals and vaccines against emerging human infectious diseases. Preclinical studies of coronavirus disease 19 (COVID-19) pathogenesis have used several animal species as models: transgenic human ACE2 mice (K18 mice), inbred BALB/c or C57BL/6N mice, ferrets, minks, domestic cats and dogs, hamsters, and macaques. However, the choice of an animal model relies on several limitations. Besides the host susceptibility, the researcher's experience with animal model management and the correct interpretation of clinical and laboratory records are crucial to succeed in preclinical translational research. Here, we summarise pathological and clinical findings correlated with virological data and immunological changes observed from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) experimental infections using different well-established SARS-CoV-2 animal model species. This essay aims to critically evaluate the current state of animal model translation to clinical data, as described in the human SARS-CoV-2 infection.

Are the dinosauromorph femora from the Upper Triassic of Hayden Quarry (New Mexico) three stages in a growth series of a single taxon?

ABSTRACT The lagerpetid Dromomeron romeri and the theropod Tawa hallae are two dinosauromorphs from the Norian (Upper Triassic) of the Chinle Formation, situated in New Mexico, USA. However, a recent study suggests the inclusion of the holotype of D. romeri (GR 218) and paratype (GR 155) and referred (GR 235) specimens of T. hallae in an ontogenetic series of a single species. The specimens GR 218 and GR 155 include just an isolated femur, while GR235 includes femora, pelvis and tail. The inclusion of the specimens in an unique ontogenetic series relies on the putative immature condition and plastic deformation of the specimen GR 218. However, as observed here, the disparity between the femora of D. romeri and T. hallae is considerably higher than those expected from the ontogenetic variance in dinosauromorphs. In addition, D. romeri shares an unique suite of traits with Dromomeron gigas, a species known from a mature specimen. Therefore, the high disparity between D. romeri and T. hallae, lack of traits shared solely between the three femora, and a suite of traits shared between D. romeri and D. gigas, precludes the inclusion of the three femora from Hayden Quarry in a growth series of a single taxon.

Visual outcomes after deep anterior lamellar keratoplasty using donor corneas without removal of Descemet membrane and endothelium / Resultados visuais após transplante lamelar anterior profundo utilizando botão corneano sem remoção da membrana de Descemet e endotélio

ABSTRACT Purpose: The optical quality of the interface after deep anterior lamellar keratoplasty (DALK) using the big-bubble technique has been shown to be excellent, leading to results comparable to penetrating keratoplasty. However, there is little in the literature with respect to the controversy surrounding the preparation of the donor cornea. The purpose of this study was to evaluate visual acuity (VA) in patients with keratoconus who underwent DALK without removal of the donor graft endothelium. Methods: The records of 90 patients who underwent DALK without the removal of the Descemet membrane (DM) and endothelium were retrospectively reviewed. Data collected included uncorrected VA (UCVA) and spectacle-corrected VA (SCVA) at 7, 30, 180 days, and 1 year postoperatively. Contact lens-corrected visual acuity (CLVA) was evaluated after 1 year of the procedure. Results: UCVA was significantly better than preoperative values at 7 days (p<0.001), 30 days (p<0.001), 180 days (p<0.001), and 1 year (p<0.001) after surgery. The 1-year postoperative mean SCVA and CLVA also improved when compared with preoperative SCVA (p<0.001 for both). Conclusions: DALK utilizing donor corneas with attached Descemet membrane and endothelium results in satisfactory VA in patients with keratoconus.

RESUMO Objetivos: A qualidade óptica da interface após ceratoplastia lamelar anterior profunda (DALK) utilizando a técnica de "Big Bubble" mostrou-se ser excelente, levando a resultados comparáveis aos da ceratoplastia penetrante. No entanto, há poucos dados na literatura com respeito à controvérsia em torno da preparação da córnea doadora. O objetivo deste estudo foi avaliar a acuidade visual (VA) em pacientes com ceratocone submetidos DALK sem a remoção da membrana de descemet e endotélio do tecido doador. Métodos: Os prontuários de 90 pacientes que foram submetidos a DALK sem a remoção da membrana Descemet (DM) e do endotélio foram avaliados retrospectivamente. Os dados coletados incluíram VA sem correção (UCVA) e VA corrigida por óculos (SCVA) aos 7, 30, 180 dias, e 1 ano de pós-operatório. A acuidade visual corrigida por lente de contato (CLVA) foi avaliada após 1 ano do procedimento. Resultados: UCVA no pós-operatório melhorou após 7 dias (p<0,001); 30 dias (p<0,001); 180 dias (p<0,001); e após 1 ano (p<0,001). Ocorreu melhora da SCVA pré-operatória quando comparada com a SCVA e CLVA após 1 ano (p<0,001 para ambos). Conclusão: Transplante lamelar anterior utilizando córneas doadas com membrana de Descemet e endotélio demonstrou resultados visuais satisfatórios em pacientes com ceratocone.

Identificação de Anticorpos Anti-PBP2a em Pacientes Colonizados e Infectados por Staphylococcus aureus Resistente a Meticilina / Identification of Anti-PBP2a Antibodies in Patients Colonized and Infected by Methicillin Resistant Staphylococcus aureus (MRSA)

Infecções causadas por Staphylococcus aureus resistente a Meticilina (MRSA) são especialmente problemáticas devido às dificuldades de tratamento e alta taxa de mortalidade associada. O principal determinante do amplo espectro de resistência aos beta-lactâmicos em cepas de MRSA é a proteína de ligação à penicilina 2a (PBP2a). A PBP2a está localizada na superfície exterior, que seriam acessíveis ao sistema imune. Não está totalmente caracterizado se o hospedeiro pode produzir anticorpos anti- PBP2a durante infecções por MRSA ou se estes anticorpos seriam protetores. O objetivo deste estudo foi investigar a presença de anticorpos anti- PBP2a em um grupo de 60 pacientes colonizados ou infectados por MRSA. Também foi investigado se estes anticorpos poderiam reduzir o crescimento bacteriano em um ensaio in vitro. Através da técnica de ELISA, os resultados mostraram que cerca de 70% das amostras apresentaram anticorpos anti- PBP2a (colonizados: 68,6% versus doentes infectados: 72 %), confirmado pelo teste Western Blot. Também foi avaliado o efeito bactericida do soro contendo anticorpos anti- PBP2a e soros controle. Uma redução do crescimento bacteriano foi observada em soros de anticorpos anti - PBP2a, em comparação com os controles. Os resultados indicam que pacientes infectados ou colonizados por MRSA produzem anticorpos contra PBP2a e que estes anticorpos pode conferir proteção contra a MRSA.

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are especially troublesome because of treatment difficulties and high mortality rate. The major determinant of the broad-spectrum beta-lactam resistance in MRSA strains is the penicillin-binding protein 2a (PBP2a). Since PBP2a is located on the outer surface, it would be accessible to the immune system. It is not fully characterized whether the host can produce anti-PBP2a antibodies during MRSA infections or whether these antibodies would be protective. The aim of this study was to investigate the presence of anti-PBP2a antibodies in a group of 60 patients colonized or infected by MRSA. It was also investigated whether these antibodies can reduce bacterial growth in an in vitro assay. Via the ELISA technique, the results showed that approximately 70% of the samples had anti-PBP2a antibodies (colonized: 68.6% versus infected patients: 72%), confirmed by the Western blotting assay. The bactericidal effect of serum containing anti-PBP2a antibodies and control sera were also evaluated. A reduction in bacterial growth was observed in the anti-PBP2a antibody sera as compared to the controls. The results indicated that MRSA-colonized or-infected patients produce antibodies against PBP2a, which can confer protection against MRSA.