Archives of Medical Research - Articles in Press

Organization of a Third-level Care Hospital in Mexico City during the 2009 Influenza Epidemic - Corrected Proof

2010-01-29

An outbreak caused by the novel swine-origin influenza A (H1N1) virus was identified in Mexico in late March 2009. The objective of this report is to describe the organization of a tertiary care center in Mexico City during the contingency. We describe the education program, the hospital organization and triaging, and unforeseen overwhelming circumstances. Educational plans were directed to follow standard, contact, and droplet precautions and to condition behavior to avoid touching the eyes, nose, or mouth. N95 respirators were distributed only to perform respiratory procedures. By the fifth month into the epidemic, four patients with hospital-acquired influenza, 467 workers with respiratory symptoms suggestive of influenza (16% of our staff), and 96 workers with confirmed novel influenza A (3% of our staff) were identified. During the first 2 months of the epidemic, 44,225 people went through the triages and only 1503 (3.3%) reached the emergency room. By the fifth month into the epidemic, four small institutional influenza outbreaks (<10 workers each) had been identified, two of them in areas with no patient contact. Molecular testing for influenza was used mainly for epidemiological purposes. Even though we had a supply, we had difficulties in meeting the demand of masks, N-95 respirators, and hand sanitizers. Due to absenteeism, the nursing administration experienced difficulties in covering shifts. Preparation is mandatory for facing an influenza epidemic. The correct use of precautions is an economic measure to limit institutional transmission. Adequate triaging is essential to meet unusual attention demands.

What Have We Learned from the Novel Influenza A (H1N1) Pandemic in 2009 for Strengthening Pandemic Influenza Preparedness? - Corrected Proof

2010-01-29

We need to apply lessons learned from previous influenza pandemics to continuously update preparedness and response plans. It has become evident that strengthening networks of international referral laboratories coupled with scaling-up efforts to expand epidemiological surveillance networks is critical for responding and mitigating the impact of influenza pandemics. The current swine-related influenza A (H1N1) pandemic has also shown that international collaboration remains a critical component to effectively respond to influenza pandemics in the current globalized world.

Diagnostic Value of Adenosine Deaminase Activity in Benign and Malignant Breast Tumors - Corrected Proof

Mahmoud Aghaei, Fatemeh Karami-Tehrani, Siamak Salami, Morteza Atri — 2010-01-29

Background: The present study was carried out to evaluate the activity of adenosine deaminase (ADA) and its isoenzymes ADA1 and ADA2 activities as a diagnostic tool in patients with benign and malignant breast disease.Methods: Total ADA, ADA1, and ADA2 activities of serum and tumor were analyzed using 58 subjects including 20 patients with benign breast disease (BBD), 34 patients with primary breast cancer, and 20 patients as normal control subjects.Results: The mean values for total ADA and ADA2 activities in the serum and tumor of BBD were significantly higher than those of healthy controls (p <0.01). Furthermore, the mean values for total ADA and ADA2 activities of patients with breast cancer were significantly higher than those of the benign group (p <0.005) and healthy subjects (p <0.0001).Conclusions: Based on the present results, it is concluded that the assessment of total ADA and ADA2 activities may be used as a reliable test for differential diagnosis of benign and malignant breast disease.

Analysis of DNA Methylation Status of the Promoter of Human Telomerase Reverse Transcriptase in Gastric Carcinogenesis - Corrected Proof

Zhenghui Wang, Jinheng Xu, Xin Geng, Weiming Zhang — 2010-01-29

Background: Telomerase is expressed in normal somatic cells and reactivated in majority of tumor cells. Human telomerase reverse transcriptase (hTERT), a catalytic subunit of telomerase, is a rate-limiting factor of telomerase activity. Evidence has shown that gastric cancer is the result of genetics and epignomics. DNA methylation is one of the most important research fields in epigenomics. It is one of the mechanisms resulting in gene silencing in carcinogenesis.Methods: Genomic DNAs were extracted from normal gastric mucosa, precancerous lesions and gastric cancer samples and were modified by sodium bisulfite. The modified genomic DNAs were amplified by PCR with primers that did not contain CpG sites. Each PCR product was sequenced. By matching the sequencing results and the original sequence, the status of each sample was obtained. PCR was carried out to identify hTERT expression.Results: The promoter of hTERT in gastric cancer was more methylated than in the precancerous lesions and normal gastric mucosa (p<0.05). hTERT was absent in normal gastric mucosa and its positive rate was higher in gastric cancer than in precancerous lesions (p<0.05).Conclusions: hTERT promoter in gastric cancer was more methylated than in the precancerous lesions and normal gastric mucosa. This may suggest that the degree of methylation of the hTERT promoter was increased during gastric carcinogenesis and may be a potential biological maker in early diagnosis of gastric cancer. During gastric carcinogenesis, expression of hTERT was increased. This may suggest that methylation of hTERT may influence expression of hTERT.

Taurine: A Potential Novel Addition to the Anti-Systemic Sclerosis Weaponry - Corrected Proof

Mohammad Kazem Fallahzadeh, Mohammad Reza Namazi, Ramesh C. Gupta — 2010-01-29

Vascular damage and immunological events leading to generation of fibrogenic fibroblasts are the main components of systemic sclerosis (SSc) pathogenesis. Superoxide anions play a role in endothelial damage by oxidizing circulating low-density lipoproteins. IL-1 plays a key role in the pathophysiology of SSc by inducing upregulation of adhesion molecules, inflammatory damage of the endothelium and tissue fibrosis. Elevated levels of proTh2 cytokines such as IL-6 in the early stages of SSc lead to enhanced fibroblast collagen production.Taurine, a semi-essential amino acid, is an antioxidant, inhibits the production of proinflammatory cytokines such as IL-1 and IL-6 and also inhibits production of TGF-β, a major fibrogenic cytokine.Therefore, we conclude that taurine may be a novel addition to the treatment armamentarium of this disabling disorder.

Comparison of the Pathology Caused by H1N1, H5N1, and H3N2 Influenza Viruses - Corrected Proof

Jeannette Guarner, Reynaldo Falcón-Escobedo — 2010-01-07

The spectrum of morbidity and mortality of H1N1, H5N1, and H3N2 influenza A viruses relates to the pathology they produce. In this review, we describe and compare the pathology of these viruses in human cases and animal models. The 1918 H1N1, the novel 2009 H1N1 pandemic virus, and H5N1 show inflammation, congestion, and epithelial necrosis of the larger airways (trachea, bronchi and bronchioles) with extension into the alveoli causing diffuse alveolar damage. Seasonal influenza A viruses (H3N2 and H1N1) have primarily caused inflammation, congestion and epithelial necrosis of the larger airways with lesser extension of the inflammatory process to alveoli. Localization of the inflammation and cellular damage relate to the presence of virus in different cell types. Infections with 1918 H1N1, the novel 2009 H1N1 pandemic virus, and H5N1 show virus in mucosal epithelial cells of the airways (from the nasopharynx to the bronchioles), alveolar macrophages, and pneumocytes, whereas infections with seasonal influenza viruses show viral antigens primarily in mucosal epithelial cells of the larger airways. The increased morbidity that has been encountered with the 2009 H1N1 virus is related to infection of cells in the upper and lower airways. The 2009 H1N1 virus shows similar pathology to that encountered with other highly virulent influenza A viruses such as the 1918 H1N1 and H5N1 viruses.

H1N1 Influenza Pandemics: Comparing the Events of 2009 in Mexico with those of 1976 and 1918–1919 - Corrected Proof

2010-01-07

Outbreaks of influenza A (H1N1) of avian- or swine-related origin have substantially impacted human populations. The most dramatic pandemic of influenza H1N1 occurred during 1918–1919 producing significant morbidity and mortality worldwide. In the 20th century, two other major pandemics took place but they were the H2N2 and H3N2 reassorted influenza strains. In 1976, a small outbreak of swine-related H1N1 in the U.S. led to a national scare but without any significant public health impact. More recently, in April 2009, in Mexico, and subsequently worldwide, an influenza (H1N1) triple reassortant strain produced >200,000 laboratory-confirmed cases and resulted in >2000 deaths. In August 2009, WHO declared this outbreak as the first influenza pandemic of the 21st century. It is critical to apply lessons learned during previous pandemics to mitigate the public health impact of the ongoing influenza pandemic in 2009. In particular, it is useful to compare the events in Mexico in 2009 to those during the Spanish influenza pandemic of 1918–1919.

Critical Analysis of Deaths Due to Atypical Pneumonia during the Onset of the Influenza A (H1N1) Virus Epidemic - Corrected Proof

2010-01-07

Background: The ongoing influenza A (H1N1) pandemic stroked Mexico and posed a huge challenge to the medical care and public health systems. This report analyzes the clinical course and process of care of patients who died due to atypical pneumonia and fulfilled the clinical criteria of suspected case of novel influenza A (H1N1) virus infection.Methods: We conducted a retrospective analysis of a series of 38 patients who died between April 7 and April 28, 2009 at Instituto Mexicano del Seguro Social (IMSS) hospitals due to severe pneumonia and respiratory distress. These cases coincided with the beginning of the outbreak, so patients did not undergo laboratory testing to diagnose influenza. According to IMSS and CDC criteria, post-hoc analysis allowed considering the presumptive diagnosis of S-OIV infection. A multidisciplinary group analyzed the information from the clinical charts, laboratory tests, radiographic studies and death certificates, using descriptive statistics.Results: Most cases were middle-aged (mean 33 years, range: 4–62 years) and previously healthy; 18.4% had an underlying chronic disease, 23.7% were obese and 7.9% were current smokers. None had received the seasonal influenza vaccine; they had cough (92%), fever (86.8%), and malaise (73.7%). The median time from disease onset to hospital admission was 6 days (range 0–8 days). All were admitted to the intensive care unit with pneumonia and/or respiratory distress. Average time from disease onset to death was 8 days (range 4–18 days).Conclusions: An increased number of severe cases of atypical pneumonia in previously healthy adults highlight the importance of the availability of a timely surveillance system able to identify sudden increases in the number of cases or presentation of apparently known diseases.