Quadruple negative SARS-CoV-2-PCR: still COVID-19 pneumonia!
[Quadruple negative SARS-CoV-2-PCR: still COVID-19 pneumonia!]
Medical history and clinical findings: A 78-year-old man fell ill with weakness, coughing and fever 19 days after a cruise in early April 2020 and was admitted 4 days later with increasing shortness of breath.
Examination and diagnosis: On admission, the patient had subfebrile temperatures, exercise dyspnea, and right-basal rales. CRP was moderately elevated and oxygen saturation was slightly reduced. Thoracic CT showed bilateral ground-glass infiltrates. Immediately after the cruise a nasopharyngeal swab was negative for SARS-CoV-2.
Therapy and course: Due to the fact that the patient’s asymptomatic wife had been tested positive for SARS-CoV-2 immediately after returning from the cruise, we suspected COVID-19 disease and admitted the patient to our isolation ward. Two nasopharyngeal swabs and bronchial lavage yielded negative results for SARS-CoV-2. Finally, suspected COVID-19 diagnosis was verified serologically.
Conclusion: In case of a high degree of clinical suspicion in combination with typical findings of thoracic imaging, the suspected diagnosis COVID-19 disease should be maintained even in case of multiple negative SARS-CoV-2-PCR. Seroconversion occurs a few days to 2 weeks after the onset of symptoms and can be used to confirm the diagnosis.
Anamnese und klinischer befund: Ein 78-jähriger Mann erkrankte Anfang April 2020 19 Tage nach einer Kreuzfahrt mit Schwäche, Husten und Fieber und wurde 4 Tage später mit zunehmender Luftnot vorstellig.
Untersuchung und diagnose: Bei Aufnahme bestanden subfebrile Temperaturen, Belastungsdyspnoe und rechtsbasale Rasselgeräusche. Das CRP war mäßig erhöht und die Sauerstoffsättigung gering reduziert. Im Thorax-CT fanden sich bilaterale Milchglasinfiltrate. Unmittelbar nach der Kreuzfahrt war ein nasopharyngealer Abstrich auf SARS-CoV-2 negativ.
Therapie und verlauf: In Kenntnis der Tatsache, dass die symptomfreie Ehefrau des Patienten unmittelbar nach Rückkehr von der Kreuzfahrt positiv auf SARS-CoV-2 getestet worden war, gingen wir von einer COVID-19-Erkrankung aus und hospitalisierten den Patienten. Zwei nasopharyngeale Abstriche und die Bronchiallavage ergaben negative Befunde für SARS-CoV-2, die Diagnose COVID-19 wurde letztlich serologisch verifiziert.
Folgerung: Bei hochgradigem klinisch-anamnestischem Verdacht in Verbindung mit typischen Befunden der Thorax-Bildgebung sollte die Verdachtsdiagnose COVID-19 auch im Falle mehrfach negativer SARS-CoV-2-PCR aufrechterhalten bleiben. Die Serokonversion tritt einige Tage bis 2 Wochen nach Symptombeginn auf und kann im Verlauf zur endgültigen Diagnosesicherung genutzt werden.
Moving from qPCR to Chip Digital PCR Assays for Tracking of some Fusarium Species Causing Fusarium Head Blight in Cereals
Fusarium Head Blight (FHB) is one of the major diseases affecting small-grain cereals, worldwide spread and responsible for severe yield and quality losses annually. Diagnostic tools, able to track Fusarium species even in the early stages of infection, can contribute to mycotoxins’ risk control. Among DNA-based technologies for Fusarium detection, qPCR (single and multiplex assays) is currently the most applied method. However, pathogen diagnostics is now enforced by digital PCR (dPCR), a breakthrough technology that provides ultrasensitive and absolute nucleic acid quantification. In our work, a panel of chip digital PCR assays was developed to quantify Fusarium graminearum, F.culmorum, F. sporotrichioides, F. poae and F. avenaceum.
The primers/probes combinations were evaluated on pure fungal samples with cdPCR technique, in comparison with the qPCR approach. Moreover, the cdPCR assays were applied to quantify Fusarium in durum wheat and oat samples, naturally contaminated or spiked with fungal DNA. For a better evaluation of infection level in plants, duplex assays were developed, able to co-amplify both plant and fungal DNA. To the best of our knowledge, this is the first study directed to the application of digital PCR to Fusarium diagnosis in plants.
Diagnosis of SARS-CoV-2 by RT-PCR Using Different Sample Sources: Review of the Literature
Objective: The most widely used diagnostic technique for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is real-time reverse transcriptase-polymerase chain reaction (RT-PCR). It can be done on different samples: nasopharyngeal swabs (NPS) or oropharyngeal swabs (OPS), and self-collected saliva. However, negative findings do not rule out infection.
Methods: A review was conceived to discuss advantages and limitations of the available diagnostic modalities for nonserologic diagnosis of SARS-CoV-2 based on RT-PCR; the article also proposes some practical suggestions to improve diagnostic reliability.
Results: A total of 16 papers (corresponding to 452 patients) of the 56 initially identified were included. Most of the papers describe findings from different samples obtained in limited case series; comparative studies are missing.
Conclusions: Diagnostic accuracy of NPS and OPS is suboptimal and the risk of contaminated aerosol dispersal is not negligible. The SARS-CoV-2 RNA can be found in self-collected saliva specimens of many infected patients within 7 to 10 days after symptom onset. There is an urgent need for comparative trials to define the diagnostic modality of choice. Adequate education and training of health care personnel is mandatory.
Description: A polyclonal antibody for detection of D-GPCR from Human. This D-GPCR antibody is for WB, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from the C-terminal region of human D-GPCR at AA range: 210-290
Description: A polyclonal antibody for detection of D-GPCR from Human. This D-GPCR antibody is for WB, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from the C-terminal region of human D-GPCR at AA range: 210-290
Description: A polyclonal antibody for detection of D-GPCR from Human. This D-GPCR antibody is for WB, IF, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from the C-terminal region of human D-GPCR at AA range: 210-290
Description: IL-15 Antibody: Interleukin 15 (IL-15) is a cytokine that regulates T and natural killer cell activation and proliferation. This cytokine and IL-2 share many biological activities as both have been found to bind common hematopoietin receptor subunits, and may compete for the same receptor, and thus negatively regulate each other's activity. The number of CD8+ memory cells is shown to be controlled by a balance between IL-15 and IL-2. This cytokine induces the activation of JAK kinases, as well as the phosphorylation and activation of transcription activators STAT3, STAT5, and STAT6. In mouse, studies suggest that IL-15 may increase the expression of apoptosis inhibitor Bcl-xL, possibly through the transcription activation activity of STAT6, and thus prevent apoptosis.
Description: IL-15 Antibody: Interleukin 15 (IL-15) is a cytokine that regulates T and natural killer cell activation and proliferation. This cytokine and IL-2 share many biological activities as both have been found to bind common hematopoietin receptor subunits, and may compete for the same receptor, and thus negatively regulate each other's activity. The number of CD8+ memory cells is shown to be controlled by a balance between IL-15 and IL-2. This cytokine induces the activation of JAK kinases, as well as the phosphorylation and activation of transcription activators STAT3, STAT5, and STAT6. In mouse, studies suggest that IL-15 may increase the expression of apoptosis inhibitor Bcl-xL, possibly through the transcription activation activity of STAT6, and thus prevent apoptosis.
Description: A wide range of well-characterized bioactive molecules that covers various targets related to GPCR, including adenosine receptor, adrenergic receptor and CXCR etc. Facilitate your research towards the insights of cancer, neurological disorders and heart diseases etc.
Description: A polyclonal antibody for detection of MMP-15 from Human, Mouse. This MMP-15 antibody is for WB, ELISA. It is affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogenand is unconjugated. The antibody is produced in rabbit by using as an immunogen synthesized peptide derived from the C-terminal region of human MMP-15 at AA rangle: 580-660
