Autor: Go! Mídia

CHROMOENDOSCOPY

Nowadays there is a great advance in diagnostic techniques in Gastroenterology. Among them, Chromoendoscopy stands out, a technique that consists in the application of dyes on the digestive mucosa to facilitate and improve the quality of diagnosis, and the staining of the mucosa also allows to visualize it in a more evident way, highlight the characteristics of the lesions already detected, detect abnormal lesions more quickly, since the details of its surface stand out with the staining, besides conferring greater sensitivity and specificity in the diagnosis of dysplasias, metaplasias or carcinoma in the various segments of the digestive tract.

Renylab manufactures a high quality endoscopic line. All dyes are registered with ANVISA and have a Certificate of Good Manufacturing Practices.

  Dyes for Endoscopy

  METHYLENE BLUE

Dye solution used to enhance Barret’s epithelium. The methylene blue when used in the esophagus, allows to confirm the presence of intestinal epithelium specialized in patients with short segments of columnar mucosa, to lift the map of extension and distribution of Barret’s epithelium, to make less likely the diagnosis of Barret’s esophagus, when the segment of mucosa of the terminal esophagus is not colored by this methodology and to orient biopsies to areas of higher risk of dysplasia and adenocarcinoma.

https://en.renylab.ind.br/produto/azul-de-metileno/

  INDIGO CARMINE

Dye solution used throughout the digestive tract, to highlight the contours of the mucosa, highlighting polyps and small flat lesions, filling folds, crypts, erosions and ulcers. It can be used in multiple situations: to highlight the villous character of Barret’s mucosa and to identify flat areas of high grade dysplasia or carcinoma, to highlight irregularities of gastric mucosa corresponding to areas of metaplasia or dysplasia and in the duodenum to highlight the atrophic aspect of the mucosa. It should be used in the detailed characterization of macroscopic lesions and in the study of high risk neoplastic mucosa without apparent lesions. There is no contraindication to its use and it does not need washing before or after its instillation.

https://en.renylab.ind.br/produto/indigo-carmim/

  CHINA INK

Dye solution usually used in colonoscopy to highlight the contours of the mucosa, highlighting polyps and small flat lesions and filling folds, crypts, erosions and ulcers. It is used for the demarcation of small and multiple lesions of the mucosa as a preoperative resource that facilitates their handling. There is no contraindication to its use and it does not require washing before or after its instillation.

https://en.renylab.ind.br/produto/tinta-nanquim/

  LUGOL

Dye solution of particular interest in the early detection of epidermal adenocarcinoma of the esophagus. The areas of the mucosa that turn yellow or pink after instillation deserve particular attention.

Lugol’s instillation is useful in the early detection of epidermoid carcinomas in the population considered at high risk (individuals with head and neck carcinoma, consumers of alcohol and tobacco in large quantities). In addition, Lugol allows a better definition of the margins of a known lesion, to design other lesional foci in the esophageal mucosa and to evaluate the existence of residual lesion after endoscopic musectomy. For some authors, the great advantage of Lugol is not in its diagnostic power, but in its ability to delimit a lesion. Other authors attribute  Lugol a significant ability to increase the sensitivity to detect high grade dysplasia or carcinoma (from 62% to 96%).

https://en.renylab.ind.br/produto/lugol/

The objective of this guide is to clarify the mechanism of action together with the techniques of application of different dyes and show the various clinical applications that endoscopic dyes have.

  PROPERTIES

The dyes used in Chromoendoscopy have particular characteristics and distinct objectives, being classified as absorption dyes, contrast dyes and reactive dyes.

  Absorption Dyes

Dyes that have this property have the ability to pass to the intracellular environment through absorption or diffusion, when they identify epithelial cells and their constituents. The chemical properties of the dye determine its fixation and its use in several situations.

  Contrast Dyes

Contrast stains have the function of highlighting the contour and topography of the mucosa, since they do not penetrate the intracellular environment.

  Reactive Dyes

Reactive dyes identify the acid producing gastric cells.

  PREPARATION OF THE MUCOSA

Before the chromoendoscopy procedure it is common to make a preparation of the mucosal surface, since it is covered with a variable amount of mucoid material. For this, mucolytic agents are used, which are substances that break and rupture the peptidic bonds of the proteins that constitute the mucus, making it more easily eliminated, because it becomes less viscous.  Ex: Acetylcysteine, dimethyl-polisiloxane, n-acetylcysteine, acetic acid.

Endoscopic dyes can be applied directly through the endoscope channel, using syringes or catheters or through spray, the most commonly used technique. The choice depends on the type of staining and the purpose for which it is applied.

 Table 1.

  CONCLUSION

The use of the Chromoendoscopy technique is simple, safe, easy to perform and inexpensive. The careful choice of dyes according to the situations presented allows greater sensitivity and specificity, making the diagnosis more reliable, safe and of higher quality.

Bibliographic References

1- Fennerty MB. Tissue staining. Gastrointestinal endoscopy. Clin N Am 1994;4:297-311.

2- Gostout C. Early lesions: staining magnifying scopes and mucosectomy. Frontiers oftherapeutic endoscopy. Post graduate course. Colonoscopy 1997; 63.

3- Kim C, Fleischer D. Colonic chromoscopy. Gastrointestinal Endoscopy Clinics N.Am. 1997; 4(3): 423-37.

4- Misumi a , ETAL. Role of lugol dye endoscopy in the diagnosis of early esophageal cancer. Endoscopy 1990; 22: 12-6.

5- Ratilal, P.0; Pires, E.C; Deus, J,R; Novais, L.A: Cromoendoscopia: Porquê colorir? GE vol. 9 2002:340-346

6- Canto M. Methylene blue chromoendoscopy for Barrett’s esophagus: Coming soon to your lgl unit? \endoscopy 2001; 54:560-8

At a time when the new coronavirus pandemic continues to advance in Brazil and in the world, the need for massive tests to detect the disease and to know the true number of infected people is growing. An accurate and correct diagnosis is essential to propose any measure related to the prevention and prognosis of infections.

The gold standard technique, considered the most accurate for diagnosis, is RT-PCR (an acronym for reverse transcription followed by polymerase chain reaction). It consists of the detection of viral RNA sequences. The test has the disadvantage of requiring a few days to be processed and the report must be issued by the laboratory.

Serological tests, on the other hand, detect the presence of class M (IgM) and G (IgG) immunoglobulins, produced by the body in response to infection by the virus. IgM is the main immunoglobulin that is formed after infection and begins to be detected between days 3 and 5 after infection, with a detection peak after the seventh day. As the infection progresses, IgM levels decrease and, conversely, IgG levels increase rapidly, with maximum detection after day 14 of infection.

The rapid test can be performed on whole blood, serum or plasma samples and the result will be available in approximately 15 minutes. The possibility of infection, however, cannot be ruled out with a negative result. This is because the production of antibodies, at the beginning of the disease, may not have been detected by TR, which caused the false negative. In such cases, it is suggested to repeat the test, to confirm, or not, the absence of infection. In addition, rapid tests can identify if the person has been previously infected, even without experiencing symptoms.

Rapid tests play an important role in understanding the dynamics of virus transmission in the population and in identifying groups at high risk of infection. They can also determine the proportion of the population that has been infected, helping to identify which communities have had a high rate of infection.

Sources:

https://www.cdc.gov/coronavirus/2019-ncov/hcp/testing-overview.html

https://saude.abril.com.br/blog/com-a-palavra/a-importancia-do-teste-rapido-para-conter-a-covid-19/

RenyLab In Vitro Diagnostics, Chemical and Pharmaceutical Industry of Barbacena-MG, carried out massive tests of its employees for Covid-19 between 07 and 08 July 2020. The test was carried out through rapid serological tests, with the aim of prioritizing the well-being and safety of employees, as well as contributing to the control of pandemic rates in Barbacena and region. All employees were tested and 100% of the results were negative for the new coronavirus.

According to the Ministry of Health, the state of Minas Gerais has the lowest incidence rate of the disease among all Brazilian states. On July 10, 2020, the state had 302.5 confirmed cases per 100,000 inhabitants, and a total of 64,035 infected by the new coronavirus, a figure much lower than São Paulo, which already has stable cases and a possible drop, and in Rio de Janeiro and Espírito Santo, which are on the rise like Minas Gerais. Large laboratories in the state of Minas Gerais point to an increase in the percentage of tests carried out mainly in the interior of the state, where only in June 60% more tests were carried out than in the previous month.

Massive tests play an important role in understanding the dynamics of virus transmission, in identifying high-risk groups and with the possibility of verifying if those analyzed have been infected or have had contact with Sars-COV-2, contributing to establish infection rates. In addition, it allows the health authorities to understand the city’s indexes and decide on the flexibility of security measures for the recovery of the economy.

RenyLab In Vitro Diagnostics is committed to the fight against coronavirus, providing products with a high quality guarantee, with a rapid test for Covid-19 with 100% accuracy (proximity between the experimentally obtained value and the true measurement value) certified by Anvisa, by FDA – Federal Agency of the United States and by the National Institute of Quality Control in Health-NIQCH.

Dengue is a disease caused by an arbovirus that has four antigenically distinct serotypes: DEN-1, DEN-2, DEN-3, and DEN-4.

Currently in Brazil circulate the four serotypes that intersect in the occurrence of epidemics, which are generally associated with the introduction of new serotypes in previously unreached areas or alteration of the predominant serotype. Dengue virus is transmitted by the bite of the mosquito of the genus Aedes, which is also responsible for the transmission of other viral diseases.

The World Health Organization (WHO) estimates that 4 billion people live in areas at risk of infection from the disease. Annually, approximately 390 million cases are recorded worldwide. In Brazil, transmission has been occurring continuously, in cyclical outbreaks, the largest of which had around 2 million reported cases.

Dengue can have different clinical presentations and an unpredictable prognosis, its incubation period varies from 3 to 15 days. The illness begins suddenly with a high fever, severe pain in the head and eyes, as well as muscle and joint pain. In the most severe cases, when the fever subsides, around the third or fourth day, bleeding occurs due to bleeding from the skin vessels and internal organs that characterize dengue hemorrhagic fever. In these cases, the clinical picture worsens rapidly, showing signs of circulatory insufficiency, intense and continuous abdominal pain, pale skin, bleeding from the nose, mouth and gums and red spots on the skin, which can cause death.

Dengue diagnosis is usually made by serology to determine the presence of antibodies against the virus in the blood or specific antigens, varying their plasma concentrations according to the moment of initiation of the infection.

NS1 is a protein that appears in detectable concentrations during dengue infection, it appears on the first day with a decrease from the fourth day, disappearing around the fifth, sixth day after the onset of symptoms.

IgM appears on average 5 to 8 days after symptoms and can last 30 to 90 days, while IgG appears on average after 14 days and can persist for life.

Given the importance of this disease, RenyLab is committed to quality by providing rapid tests with results in 20 minutes, with high rates of sensitivity and specificity with certified efficacy and strict quality control.

The Renylab Dengue Immunotest is a solid phase immunochromatographic test that qualitatively and differentially detects IgG, IgM antibodies against the four serotypes of dengue virus in human serum and plasma.

The test is fast, safe and represents an important tool for the treatment of patients with suspected dengue.

RenyLab is determined to contribute and support its clients and partners in this difficult time of the COVID-19 pandemic. We would like to share with you an article on gastrointestinal endoscopy (GIE) on the impact of coronavirus on endoscopic procedures. In this article you will find recommendations with a specific focus on personal protection and dress code, to prevent the spread of COVID-19.

We have summarized the most important steps below. If you want to access the full article click here.

Some important steps we would like to point out:

• Every patient entering the endoscopy room must wear a mask to protect others. Patients considered at risk should also wear gloves;
• For clinic staff and physicians, the recommendation is to maintain a safe distance from patients throughout the procedure. According to the article, it is mandatory to wash your hands with soap and water or an alcohol-based disinfectant:

1. Before and after interaction with the patient;
2. Contact with potentially infected surfaces;
3. Before putting on and after taking off any personal protective equipment, including gloves.

• In the article you will find the minimum composition of an individual protection kit in endoscopic procedures, which can be modified depending on the risk.