Serum levels of inflammatory cytokines in mercury mining workers in a precarious situation: A preliminary study

Mercury is a ubiquitous environmental xenobiotic; the primary sources of exposure to this metal are artisanal gold mining and the direct production of mercury. In Mexico, artisanal mercury mining continues to be an important activity in different regions of the country. Exposure to mercury vapors releases can have severe health impacts, including immunotoxic effects such as alterations in cytokine profiling. Therefore, in the present work, we evaluated the inflammatory cytokines profile in the blood serum of miners exposed to mercury. A cross-sectional observational study was performed on 27 mining workers (exposed group) and 20 control subjects (nonexposed group) from central Mexico. The mercury urine concentration (U-Hg) was determined by atomic absorption spectrometry, and IL-2, IL-6, IL-8, IL-10, and TNF-α were measured using a Multiplex Assay. The results showed that the U-Hg in the miners had a median value of 552.70 μg/g creatinine. All cytokines showed a significant increase in the miner group compared with the control group, except for TNF-α. In addition, we observed a positive correlation between U-Hg concentration and cytokine levels. In conclusion, mercury exposure correlated with cytokine levels (considered acute inflammatory marker) in miners; therefore, workers exposed to this metal show an acute systemic inflammation that could lead to alterations in other organs and systems.

[Comment on article "Variability of hemoglobin and hematocrit determined in blood gas equipment"]

´The analysis of samples on different equipment may lead to variation between results; in the article "Variability of hemoglobin and hematocrit determined in blood gas equipment", the authors talk about the variability of hemoglobin and hematocrit between an automated hematology analyzer and an arterial blood gas analyzer. Information is requested on some aspects considered relevant to improve the understanding of the conclusions.

[Obtaining blood components in blood banks]

After the first successful blood transfusion, different difficulties of a liquid tissue were overcome; this liquid required special conditions to keep its characteristics with minimal alterations and, thus, to be able to be used in patients who needed it. Subsequently, techniques that also made possible to separate this liquid into its different components for its use were discovered, allowing a more specific treatment of the deficiencies of patients when administering cellular or non-cellular elements. With this, a new area arose within the blood banks to obtaining components. This area became the central point of convergence of all the processes involved in obtaining components, which include the biological qualification of each one of the units, as well as their labeling and release for the different distribution in transfusion services. It is important to highlight that the main source of components is obtained from whole blood; its processing for several decades was an artisanal operator-dependent process; however, with the evolution of technology, now it is possible to carry it out in an automated manner; likewise, today it is possible to obtain components directly from the donor's whole blood by separating it in real time by means of apheresis, which allows obtaining the component of interest and returning the remainder to the donor.

[External Quality Control in Immunohematology of National Medical Center's Blood Bank. History and present]

For the proper functioning of the Immunohematology Area, an External Quality Control was established since 1973 through a program that evaluates the performance of the laboratories of the Blood Bank and transfusion services that carry out immunohematology tests. This program consists of sending panel cells to participating blood banks or services, which are phenotyped erythrocyte samples previously studied as problem cases but whose results are unknown by the participating laboratories. The processes in which the program is of most importance are determination of the ABO group, determination of Rh, performance of the direct and indirect Coombs test, and pre-transfusion compatibility tests. It was carried out an observational and retrospective study of the results obtained in the 2020 period from 104 units participating in the Immunohematology Quality Control Program of the National Medical Center's Blood Bank. A panel of cells was sent for external quality control of immunohematology every 45 days, resulting in 9 panels for each unit in the studied period. Compliance with the program was observed in the general result (79.6%), i.e., there was a decrease in the participation of the registered units. Of a maximum score of 100% to be obtained, it was observed a general result of 95.3% compliance of the participating units. The results obtained confirm the good general training of the immunohematology laboratories of the participating units. Yet, as in any external control program, it becomes clear that obtaining an erroneous result is a risk that can occur in any laboratory.

[Molecular biology in a blood bank]

Medicine has had a vertiginous advance in the last two centuries. After the first successful transfusions, transfusional medicine and blood banks arose. The ladder perform vital functions, from donor screening to the studies for the analysis of blood that are carried out before its use for transfusion and the follow-up of patients who receive blood components. Molecular biology is highly relevant in these activities, since it has allowed the reduction of window periods for the detection of diseases transmissible by blood; it has allowed the complete study of the typing of blood groups and HLA molecules, and it has allowed the adequate phenotypic interpretation of patients and donors by being able to have their genotype. The most relevant impact of the implementation of molecular biology techniques was the screening for the detection of transfusion-transmissible diseases in blood donors, which has allowed improving the safety of the components obtained. Molecular biology techniques applied in the study of the donor-recipient have allowed better care of patients who have required a transfusion or transplant. In this work, it is reviewed the importance of molecular biology in blood banks, with which the care for the Instituto Mexicano del Seguro Social beneficiaries has improved, as well as for the blood donors who are mostly not insured.

[Antiproliferative, apoptotic, and antimigratory activities of kafirins on cervical cancer-derived cell lines]

Background

Cervical cancer is one of the leading causes of death in women worldwide, both in developed and developing countries. Therefore, effective treatment of cervical cancer with potential anti-tumor drugs is important. However, new treatments inspired by nutritional medicine are needed.

Objective

To use the human cervical cancer cell lines HeLa and SiHa to evaluate the antiproliferative, apoptotic, and migratory activity of sorghum (kafirins).

Materials and methods

The anticancer effects of the kafirins were examined by counting cells, MTT assays, apoptosis, and migration assays.

Results

This investigation showed that sorghum induced growth inhibition of HeLa and SiHa cells at a significant level. The growth inhibition is dose-dependent and irreversible. When HeLa and SiHa cells were treated with sorghum due to the activity of kafirins, morphological changes were observed, which were identified through the formation of apoptopic bodies. And the kafirins at concentrations of 37.5, 75, 150, and 300 μg/mL decreased the migration of HeLa cells and SiHa cells.

Conclusion

This paper demonstrates the induction of antiproliferative, apoptotic, and anti-migratory activity in HeLa and SiHa cells by kafirins. Sorghum may be used as a nutraceutical with potential cancer-prevention benefits.

[Systematization of interviews with altruistic blood donors during mobile campaign]

Background

The mobile campaigns of altruistic blood donation are one of the main actions of the Blood Bank of the Hospital de Especialidades "Dr. Bernardo Sepúlveda Gutiérrez". With the arrival of the new normal, after the COVID-19 pandemic, it was necessary to reactivate these actions according to the population's characteristics.

Objective

To identify socio-cultural characteristics that enhance or limit voluntary or altruistic blood donation.

Material and methods

Qualitative exploratory research, through a semi-structured interview with stratified sampling, universe of partial population of those attending blood donation; only altruistic donors were considered randomly, and representative proportions of the population subgroup were determined.

Results

Most of the donors interviewed were preliminary donors who approached the blood donation tent without focused promotion. Health professionals showed greater identification to altruistic blood donation. Donors declared a lack of donation culture as the main factor limiting this human activity. Finally, they considered the accessibility to the blood donation tent as determinant for altruistic blood donation.

Conclusions

Twelve recommendations were established to the Blood Bank, with which the intention is to propose strategies and establish research channels that increase the impact on the promotion of altruistic blood donation in future campaigns.

[Vital impetus… the blood]

In 2022, 2 years on from the start of the pandemic, the Instituto Mexicano del Seguro Social (IMSS, Mexican Institute for Social Security) has been reorganizing its services at full, out of which blood banks play a key role. In addition, on June 14 it is celebrated the World Blood Donor Day by the World Health Organization and this year Mexico was the host country for the celebration. Therefore, it is important to highlight the work carried out in blood banks, ranging from their main activity, which is the recruitment of blood donors and the blood components production, to the different interventions they have in the field of transplantation, diseases emerging diagnosis and the development of new therapeutic modalities, such as, for example, cell therapy.

[Seroprevalence of anti-SARS-CoV-2 IgG antibodies in resident physicians]

Background

COVID-19 pandemic spread around the world swiftly; there are several diagnostic strategies available. Health workers, especially medical residents (MR), are a high-risk population for acquiring this infection.

Objective

To estimate the seroprevalence of antibodies against SARS-CoV-2 and the associated factors in MR of a third level hospital.

Material and methods

330 MR from different specialties were evaluated with a questionnaire and collection of blood samples for analysis by microparticle chemiluminescent immunoassay. The prevalence of previous infection was defined by seropositivity of these antibodies. Descriptive statistics and concordance between the RT-PCR tests and the presence of anti-SARS-CoV-2 IgG were used.

Results

Of 330 MR, 84.5% actively participated in COVID patient care. One out of 3 reported symptoms of COVID-19; in 67.6% the possible site of infection was a hospital setting not associated with the COVID area. Out of 71 symptomatic subjects, 61.9% underwent RT-PCR against SARS-CoV-2; 20 were positive. In 15.8% of the total, the presence of anti-SARS-CoV-2 IgG antibodies was determined. Only 1 out of 3 subjects with a positive PCR had antibodies, and 11.3% of the cases, even with a positive RT-PCR test, did not develop humoral immunity.

Conclusions

The seroprevalence was lower than that reported at the national level, potentially due to protection measures. The main risk factor was contact with the virus in areas of the hospital not related to COVID, making it imperative to reinforce security protocols in those spaces.

[Impact of the analitycal quality for the infectious serology]

The application of quality and its scope have diversified. From this perspective, quality assurance applied to analytical tests (performed in clinical laboratories or blood banks) for the detection of infectious markers is one of the concepts that has gained strength in the last 10 years. The official Mexican standards require ensuring the quality of the published results and for their compliance it is recommended the use of international guides and guidelines that describe good practices that can be applied when carrying out this activity, without losing sight of the fact that everything related to quality assurance must be supported by the implementation of a quality management system. Thus, by using materials selected correctly and in accordance with official regulatory requirements, a good statistical analysis and the appropriate tools, the quality assurance of the analytical phase of the laboratory process in the screening of infectious markers can bring great benefits to the emission of clinically useful results by monitoring indicators and applying the necessary corrective actions, in order to reduce the risk of unfavorable results for patients and donors.

[PCR for COVID in the transplant protocol]

Background

Since the beginning of the SARS-CoV-2 pandemic, identifying the COVID-19 pathophysiology not only has been addressed to applying diagnostic tests or preventing through vaccines, but also to the timely detection, especially of patients in risk groups such as those in transplants areas (renal, hematology, etcetera). In the case of these patients, using RT-PCR tests avoids putting them at risk by subjecting them to states of immunosuppression that could aggravate their situation if they were faced with an onset of a COVID-19 infection.

Objective

To present the results of patients of a transplant unit tested for SARS-CoV-2.

Material and methods

Descriptive, observational, cross-sectional, and retrolective study. Data of results of RT-PCR tests of patients who underwent transplantation from June 2021 to April 2022 in a third level hospital were collected.

Results

755 tests were done to patients who underwent transplantation. 384 (50.8%) were women. Out of all patients, only 73 (9.7%) were positive to SARS-CoV-2.

Conclusions

Implementing RT-PCR tests as a transplant protocol to detect SARS-CoV-2 prevents fatal complications due to COVID infection to donors and receptors.

[History of the 60 years of the 21th Century National Medical Center's Central Blood Bank]

The Blood Bank of the 21th Century National Medical Center is an important piece in the field of transfusion medicine at the national level. Its history shows that it has been in constant change to be able to meet the needs in an adequate and safe manner for both donors and patients. This article shows the advances that the Central Blood Bank has had since its inauguration. This bank has areas of Immunohematology, Donors Assistance, Serology, Fractionation and Storage Studies. These areas have been improving constantly and areas dedicated to molecular biology have been implemented, which makes the bank remain a reference center at the national level. The bank has qualified personnel who have also been involved in teaching courses for personnel from other units of the Instituto Mexicano del Seguro Social (Mexican Institute for Social Security), as well as in disseminating research studies carried out within the bank. The Blood Bank of the 21th Century National Medical Center is a pillar in transfusion medicine care at the national level and it is a reference center for specialized studies.

[Blood donors, risk factors and sexual orientation]

In order to reach high-quality blood-components, it is necessary that people who wish to be a blood donor shall observe a series of conditions that guarantee the least possible risk for the recipient and themselves. According to international standards, an adequate and reliable supply of safe blood can be assured by a stable base of regular, voluntary, unpaid blood donors (altruistic), which is a goal set by the World Health Organization; unfortunately in our country it only represents around 3%, despite the efforts of different institutions. In addition, the population is unaware of risk factors that prevent donating, due to the low culture of this issue. Therefore, it is necessary to implement strategies to disseminate that blood donation is a privilege and donors must have a lifestyle that allows being in a position to be able to carry out this act of solidarity, including having an excellent state of health, adequate dietary hygiene habits, and a lifestyle free of risky behaviors, which includes the non-use of substances as well as a sexual behavior free from situations of exposure to infectious agents transmitted by transfusion. In particular, this point has been controversial, since some groups of the LGBT community have interpreted it as discrimination. The aim of this article is to highlight the difference between the risk factor, particularly for patients who require blood-components for their treatment and sexual behavior.

[Anti-SARS-CoV-2 seroprevalence in administrative staff of the Mexican Institute for Social Security]

BACKGROUND

Asymptomatic subjects, the lack of diagnostic tests and, in countries like Mexico, the epidemiological surveillance method does not allow to establish the real number of infections in the COVID-19 pandemic. Frontline health personnel, as well as other groups related to priority activities are considered of high risk. We included administrative workers in contact with health personnel in the hospital units of the Mexican Institute for Social Security (IMSS, according to its initials in Spanish).

OBJECTIVE

To identify the seroprevalence of antibodies to SARS-CoV-2 in IMSS' administrative staff who does not treat patients.

MATERIAL AND METHODS

76 volunteer participating individuals were incluided; IgG antibodies against the SARS-CoV-2 nucleoprotein were measured. A questionnaire was administered to the participants in order to identify possible risk factors.

RESULTS

76 participants were included (39 men, 51.7%), with a median age of 42 years. 29 out of 76 subjects (38.2%), whose median age was 38 years (range 18-69 years); 15 men (51.7%), and 14 women (48.3%). A higher percentage of positive subjects under 45 years of age (n = 20, 84.2%) was observed than those aged 45 or over (n = 9, 25%), with an OR of 3 (95% CI 1.13-7.96, p = 0.03). No statistically significant difference was found regarding the type of comorbidity.

CONCLUSIONS

The prevalence identified shows an important circulation of the virus in the administrative staff.

The immunogenetic diversity of the HLA system in Mexico correlates with underlying population genetic structure

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ'≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.

[Excessive spending by misuse of clinical laboratory]

Seventy five percent or more of a diagnosis comes from a proper medical history along with an excellent physical examination. This leaves to the clinical laboratory the function of supporting the findings, determining prognosis, classifying the diseases, monitoring the diseases and, in the minimum of cases, establishing the diagnosis. In recent years there has been a global phenomenon in which the allocation of resources to health care has grown in an excessive way; the Instituto Mexicano del Seguro Social is not an exception with an increase of 29 % from 2009 to 2011; therefore, it is necessary to set containment and reduction without compromising the quality of patient care.

[Stem cells biobanks for cell therapy. A reality in Mexico]

The storage and acquisition of human tissue samples have always been present in medicine for centuries; however, biobanks activity has only recently appeared as such. The aim of this review is to give a global perspective of the positioning of biobanks, particularly an overview of what happens in Mexico. One of the main challenges of our country is to establish concerted actions, in wich biobank networks will be developed and have the opportunity to share and create new science, and to build bridges to facilitate improved practices and standardization of biobanks.

[Two different techniques for volume blood reduction obtained from umbilical cord]

BACKGROUND

To preserve the umbilical cord blood (UCB), the volume containing the cells must be reduced before freezing, but the quality, quantity and functionality of the cells has to be preserved during this procedure. The aim is to compare the performance of two different techniques for volume reduction.

METHODS

A semiautomatic system and an automatic system were compared as two different UCB volume reduction techniques. Total nucleated cell (TNC) counts and viability were measured before and after volume reduction. The CD34+ cell counts also were measured.

RESULTS

Seventy units of cord blood cells (UCB) were collected. Thirty-three volume reduction procedures were performed by semiautomatic system and thirty-seven by automatic system. The volume recovered and the CD34+ count in both techniques was similar, although the viability differed slightly (1% higher by Optipress II).

CONCLUSIONS

The semiautomatic and automatic techniques are suitable to reduce volumes of UCB units.

[Detection of Trypanosoma cruzi in blood donors]

BACKGROUND

The American trypanosomiasis is the second parasitic disease in importance after paludism and one of the main mechanism of transmission is a blood transfusion. Our objective was to measure the effect the Tripanosoma Cruzi screening test in blood banks in the Mexican Institute of Social Security.

METHODS

Information was obtained from each unit of blood collected. The Tripanosoma cruzi prevalence was calculated only in samples with double reactivity in the blood banks.

RESULTS

Of 71 blood banks, only 26 had been doing T. Cruzi screen; after implementation of integrated services 55 are doing the screening. There were 935 donors with double reactivity to the T. Cruzi test from 230,074 samples. The national prevalence was 0.406%. The seroprevalence was 0.013% to 3.118%.

CONCLUSIONS

The screening of the T. cruzi improved the detection and increased the safety and the prevention of its transmission by blood transfusion.

[Prevalence of hepatitis C virus in the blood bank at Centro Médico Nacional La Raza]

INTRODUCTION

There are no records on the prevalence of infection by HCV in Mexican population. The central area of Mexico is a highly dense demographic zone and is the influence area of the second blood bank in Latin America in terms of affluence.

MATERIAL AND METHODS

We prospectively studied the prevalence and genotypes of HCV infection in 5105 individuals attending the Central Blood Bank of Centro Médico Nacional La Raza regardless if they were accepted or rejected as donors. We applied a quimiolumiscence assay as a screening test. A recombinant immunoassay (RIBA) and a qualitative polymerase chain reaction (PCR) were performed as confirmatory tests and to detect viremia, respectively. Virus genotype was identified by means of a Line Immuno Probe Assay in PCR positive samples.

RESULTS

The overall prevalence of HCV infection was 0.195% (10/5105). Viremia was detected in 90% of the subjects. The prevalence of accepted donors (0.087%) was significantly lower (p = 0.017) than that of the rejected ones (0.421%). Among viremic subjects, 60 % were infected with genotype 2 and 40% with a subtype combination (a/b) of genotype 1.

DISCUSSION

The prevalence of HCV infection in our population was significantly lower than the world mean prevalence estimated in 3 %. A higher prevalence of genotype 2 in asymptomatic individuals contrasts with previous studies with a selected population where genotype 1 prevailed.