Publications by authors named "Michael Astudillo"

Penile melanomas (PM) are an exceedingly rare subtype of mucosal melanoma (MM), and we reviewed the clinicopathologic features and molecular profile in 8 PMs. The patient ages ranged from 46 to 78 (mean: 62.8) years with involvement on the glans (n=5; 62.

View Article and Find Full Text PDF

Background: Understanding immunogenicity and effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines is critical to guide rational use.

Methods: We compared the immunogenicity of mRNA-1273, BNT-162b2, and Ad26.COV2.

View Article and Find Full Text PDF
Article Synopsis
  • A study compared the immune responses of three COVID-19 vaccines (mRNA-1273, BNT-162b2, and Ad26.COV2.S) among adults in Massachusetts to understand their effectiveness.
  • One dose of mRNA vaccines produced antibody levels similar to those in people who recovered from COVID-19, while Ad26.COV2.S had lower antibody levels and less neutralization ability.
  • Overall, mRNA vaccines showed better immune responses and effectiveness against infection and hospitalization compared to Ad26.COV2.S, highlighting varying vaccine performance.
View Article and Find Full Text PDF
Article Synopsis
  • The study analyzed antibody responses in 113 COVID-19 patients, finding that severe cases have heightened inflammatory markers and high levels of anti-RBD antibodies.
  • High neutralization potency of antibodies was linked to better survival rates, indicating that effective humoral immunity is vital for fighting the virus.
  • The findings stress the need for vaccines or treatments that can offer broad protection against future coronaviruses, as patient sera did not effectively neutralize a related bat coronavirus.
View Article and Find Full Text PDF

Distinguishing hypertrophic lichen planus (HLP) and squamous cell carcinoma (SCC) can be diagnostically challenging because of overlapping clinical and histopathological features. This study characterizes histopathological features in HLP and SCC, assessing their utility in diagnosing atypical squamous proliferations. We compared 12 histopathological features of 15 HLP and 11 SCC biopsies from the lower extremities.

View Article and Find Full Text PDF

The rapid worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has propelled the rapid development of serologic tests that can detect anti-SARS-CoV-2 antibodies. These have been used for studying the prevalence and spread of infection in different populations, and helping establish a recent diagnosis of coronavirus disease 2019 (COVID-19), and will likely be used to confirm humoral immunity after infection or vaccination. However, nearly all lab-based high-throughput SARS-CoV-2 serologic assays require a serum sample from venous blood draw, limiting their applications and scalability.

View Article and Find Full Text PDF

Objectives: We validate the use of a lateral flow immunoassay (LFI) intended for rapid screening and qualitative detection of anti-SARS-CoV-2 IgM and IgG in serum, plasma, and whole blood, and compare results with ELISA. We also seek to establish the value of LFI testing on blood obtained from a capillary blood sample.

Methods: Samples collected by venous blood draw and finger stick were obtained from patients with SARS-CoV-2 detected by RT-qPCR and control patients.

View Article and Find Full Text PDF

COVID-19 exhibits variable symptom severity ranging from asymptomatic to life-threatening, yet the relationship between severity and the humoral immune response is poorly understood. We examined antibody responses in 113 COVID-19 patients and found that severe cases resulting in intubation or death exhibited increased inflammatory markers, lymphopenia, and high anti-RBD antibody levels. While anti-RBD IgG levels generally correlated with neutralization titer, quantitation of neutralization potency revealed that high potency was a predictor of survival.

View Article and Find Full Text PDF

We measured plasma and/or serum antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in 343 North American patients infected with SARS-CoV-2 (of which 93% required hospitalization) up to 122 days after symptom onset and compared them to responses in 1548 individuals whose blood samples were obtained prior to the pandemic. After setting seropositivity thresholds for perfect specificity (100%), we estimated sensitivities of 95% for IgG, 90% for IgA, and 81% for IgM for detecting infected individuals between 15 and 28 days after symptom onset. While the median time to seroconversion was nearly 12 days across all three isotypes tested, IgA and IgM antibodies against RBD were short-lived with median times to seroreversion of 71 and 49 days after symptom onset.

View Article and Find Full Text PDF

Sensitive and specific severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic assays are needed to inform diagnostic, therapeutic, and public health decision-making. We evaluated three commercial serologic assays as stand-alone tests and as components of two-test algorithms. Two nucleocapsid antibody tests (Abbott IgG and Roche total antibody) and one spike protein antibody test (DiaSorin IgG) were included.

View Article and Find Full Text PDF

SARS-CoV-2 antibody testing allows quantitative determination of disease prevalence, which is especially important in high-risk communities. We performed anonymized convenience sampling of 200 currently asymptomatic residents of Chelsea, the epicenter of COVID-19 illness in Massachusetts, by BioMedomics SARS-CoV-2 combined IgM-IgG point-of-care lateral flow immunoassay. The seroprevalence was 31.

View Article and Find Full Text PDF

The diagnosis of COVID-19 requires integration of clinical and laboratory data. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic assays play a central role in diagnosis and have fixed technical performance metrics. Interpretation becomes challenging because the clinical sensitivity changes as the virus clears and the immune response emerges.

View Article and Find Full Text PDF
Article Synopsis
  • - The study evaluated the performance of ten quick lateral flow assays and two lab-based tests for detecting antibodies against SARS-CoV-2, focusing on the time after symptom onset and previous test samples.
  • - It found that seropositivity increased over time, peaking over 20 days after symptoms began, but test specificity varied between 84.3% and 100%, mainly influenced by IgM results.
  • - Recommendations from the study emphasize optimizing seropositivity thresholds and ensuring proper reader training to improve the reliability of these assays, with four tests showing over 80% positivity and over 95% specificity in later time intervals.
View Article and Find Full Text PDF

Critical to managing the spread of COVID-19 is the ability to diagnose infection and define the acquired immune response across the population. While genomic tests for the novel Several Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) detect the presence of viral RNA for a limited time frame, when the virus is shed in the upper respiratory tract, tests able to define exposure and infection beyond this short window of detectable viral replication are urgently needed. Following infection, antibodies are generated within days, providing a durable read-out and archive of exposure and infection.

View Article and Find Full Text PDF

Background: Characterizing the humoral immune response to SARS-CoV-2 and developing accurate serologic assays are needed for diagnostic purposes and estimating population-level seroprevalence.

Methods: We measured the kinetics of early antibody responses to the receptor-binding domain (RBD) of the spike (S) protein of SARS-CoV-2 in a cohort of 259 symptomatic North American patients infected with SARS-CoV-2 (up to 75 days after symptom onset) compared to antibody levels in 1548 individuals whose blood samples were obtained prior to the pandemic.

Results: Between 14-28 days from onset of symptoms, IgG, IgA, or IgM antibody responses to RBD were all accurate in identifying recently infected individuals, with 100% specificity and a sensitivity of 97%, 91%, and 81% respectively.

View Article and Find Full Text PDF

Background: Serological tests are crucial tools for assessments of SARS-CoV-2 exposure, infection and potential immunity. Their appropriate use and interpretation require accurate assay performance data.

Method: We conducted an evaluation of 10 lateral flow assays (LFAs) and two ELISAs to detect anti-SARS-CoV-2 antibodies.

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how somatic cells are turned into induced pluripotent stem cells (iPSCs), focusing on changes in chromatin structure and epigenetic patterns.
  • Dppa2 and Dppa4 are identified as essential factors for resetting the epigenome to a pluripotent state, enhancing the efficiency and speed of reprogramming somatic cells with Oct4, Klf4, Sox2, and Myc (OKSM).
  • The research reveals that Dppa2/4 help decompact chromatin and activate embryonic stem cell enhancers while silencing somatic genes, shedding light on the mechanisms behind gaining pluripotency.
View Article and Find Full Text PDF

A rare case of subacute cardiac tamponade developed in a 71-year-old patient after a left lower lobe sleeve lobectomy for cancer. The patient was successfully treated by drainage of the pericardial effusion by a pigtail catheter. The exact cause is uncertain, but it appears to include an inflammatory component.

View Article and Find Full Text PDF

Lrig1 is the founding member of the Lrig family of transmembrane leucine-rich repeat proteins, which also includes Lrig2 and Lrig3. Lrig1 is a negative regulator of oncogenic receptor tyrosine kinases, including ErbB and Met receptors, and promotes receptor degradation. Lrig1 has recently emerged as both a tumor suppressor and a key regulator of epidermal and epithelial stem cell quiescence.

View Article and Find Full Text PDF