Multisystem Failure in Fatal Dengue: Associations between the Infectious Viral Serotype and Clinical and Histopathological Findings

Dengue is the most important arthropod-borne viral infection of humans. However, its viral pathogenesis is still unknown. The information collected from dengue fatal cases is crucial for understanding the complex interactions between virulence and host factors. This study aimed to establish possible associations between the clinical characteristics, histopathological changes, replication, and tissue location of viral serotypes in dengue fatal cases. Clinical and histopathological characterizations, antigen localization in tissue, and detection of the infecting serotype and replication using real-time polymerase chain reaction were all performed on the dengue fatal cases. The majority of the cases involved people under the age of 20. Bleeding (48.3%), abdominal pain (44.8%), myalgia (52.9%), and headache (48.3%) were the most common clinical manifestations in the cases. There was multiorgan pathology, with histopathological changes primarily in the liver, spleen, and lung. Similarly, the viral antigen was found primarily in these organs; however, there were no associations between tissue changes, viral location, infecting serotypes, and replication processes. Dengue infection should be considered a multiorgan disease, the outcome of which is possibly not associated with the infecting viral serotype.

Fatal acute undifferentiated febrile illness among clinically suspected leptospirosis cases in Colombia, 2016-2019

BACKGROUND

Acute undifferentiated febrile illness is a common challenge for clinicians, especially in tropical and subtropical countries. Incorrect or delayed diagnosis of febrile patients may result in medical complications or preventable deaths. Common causes of acute undifferentiated febrile illness in Colombia include leptospirosis, rickettsioses, dengue fever, malaria, chikungunya, and Zika virus infection. In this study, we described the acute undifferentiated febrile illness in postmortem patients reported as suspected cases of leptospirosis through the national leptospirosis surveillance in Colombia, 2016-2019.

METHODOLOGY/PRINCIPAL FINDINGS

We retrospectively analyze human fresh and formalin-fixed tissue samples from fatal suspected leptospirosis cases reported by the Public Health Laboratories in Colombia. Leptospirosis confirmation was made by immunohistochemistry, real-time polymerase chain reaction (PCR) in the tissue samples. In some cases, the serum sample was used for confirmation by Microagglutination test (MAT). Simultaneously, tissue samples were tested by PCR for the most common viral (dengue, Zika, and chikungunya), bacterial (Brucella spp., and Rickettsia spp.), and parasitic (malaria). Fresh tissue samples from 92 fatal suspected leptospirosis cases were reported to the National Reference Laboratory from 22/32 departments in Colombia. We confirmed leptospirosis in 27% (25/92) of cases. Other pathogens identified by real-time PCR were Brucella spp. (10.9%), Rickettsia spp. (14.1%), and dengue (2.2%). Dengue (6.9%), hepatitis (3.5%), and Yellow Fever cases (2.2%) were detected by the pathology. All patients were negative for chikungunya and Plasmodium spp. Most cases were classified as undifferentiated febrile illnesses (45.7%; 42/92).

CONCLUSIONS/SIGNIFICANCE

This study underscores the importance of early and accurate recognition of leptospirosis to prevent mortalities. Moreover, it draws attention to the existence of other febrile syndromes in Colombia, including rickettsiosis and brucellosis, that currently lack sufficient human surveillance and regular reporting. Expanding laboratory surveillance to include viruses such as Hantavirus, Mayaro virus, Oropouche virus, and West Nile virus is crucial.

Genotyping of dengue virus from infected tissue samples embedded in paraffin

Dengue has become one of the vector-borne diseases that affect humans worldwide. In Latin American countries, Colombia is historically one of the most affected by epidemics of this flavivirus. The underreporting of signs and symptoms of probable cases of dengue, the lack of characterization of the serotypes of the infection, and the few detailed studies of postmortem necropsies of patients are among other conditions that have delayed progress in the knowledge of the pathogenesis of the disease. This study presents the results of fragment sequencing assays on paraffin-embedded tissue samples from fatal DENV cases during the 2010 epidemic in Colombia. We found that the predominant serotype was DENV-2, with the Asian/American genotype of lineages 1 and 2. This work is one of the few reports of the circulating genotypes of dengue during the 2010 epidemic in Colombia, one of the most lethal dates in the country's history.

Fetal demise and SARS-CoV-2 infection during pregnancy: Histopathological and immunohistochemical findings of three cases referred to the Colombian National Institute of Health

BACKGROUND

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection during pregnancy is related with adverse maternal, fetal, and neonatal outcomes. Placental SARS-CoV-2 involvement may include various degrees of inflammation and malperfusion leading to diverse pregnancy complications.

METHODS

Placental, fetal and umbilical cord samples of three fetal demise cases that occurred in the context of maternal SARS-CoV-2 infections were analyzed. Cases were notified to the Colombian SARS-CoV-2 National Surveillance System. RT-PCR and immunohistochemistry (IHC) analysis were employed to identify potential tissue viral involvement.

RESULTS

RT-PCR and IHC confirmed the presence of viral genomes and antigens in placental and umbilical cord tissues. Histopathological analysis revealed findings consistent with placental malperfusion and inflammation.

CONCLUSIONS

SARS-CoV-2 infection during pregnancy can lead to placental dysfunction and damage compromising fetal survival. Many questions regarding SARS-CoV-2 dynamics during pregnancy including placental physiopathology and in utero transmission are still pending definitive answers.

Microbiota, Immune System and Autism Spectrum Disorders: An Integrative Model Towards Novel Treatment Options

The functioning of the central nervous system (CNS) is the result of the integration of bidirectional messages between the brain and peripheral organs. Despite the anatomical separation, gut microbiota, i.e., the microorganisms colonising the gastrointestinal tract, is related to the CNS through the so-called “gut–brain axis” that is also involved in immune processes. The recent literature indicates that the gut microbiota may affect brain functions through endocrine and metabolic pathways, antibody production and the enteric network, while supporting its possible role in the onset and maintenance of several neuropsychiatric and neurodevelopmental disorders, such as autism spectrum disorders (ASDs). The term ASDs includes autistic disorder, Asperger’s syndrome, childhood disintegrative and pervasive developmental disorders not otherwise specified different. All these conditions are characterised by persistent deficits in social communication and social interaction, as well as limited and repetitive behaviours, interests or activities. In the last two decades, an impressive number of cross-sectional studies reported significant differences in microbiota composition between children with an ASD and controls, thus strengthening the hypothesis of a possible link between GI dysbiosis and ASD. The amount of studies documenting the possible involvement of microbiota in ASD pathogenesis led to considering whether treatments acting on gut flora could ameliorate ASD symptoms. The available findings, although preliminary, would indicate data gut microbiota might represent an interesting field of research for a better understanding of the pathophysiology of ASD (of also of other neuropsychiatric disorders), and possibly a target for the development of innovative treatments just labelled as “psychobiotics”.

Disclosure

No significant relationships.

Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

Deconstructing the landscape of fear in stable multi-species societies

Animal distributions are influenced by variation in predation risk in space, which has been described as the "landscape of fear." Many studies suggest animals also reduce predation risk by eavesdropping on heterospecific alarm calls, allowing them to occupy otherwise risky habitats. One unexplored area of study is understanding how different species' alarms vary in quality, and how this variation is distributed in the landscape. We tested this phenomenon in a unique system of avian mixed species flocks in Amazonian rainforests: flock mates (eavesdropping species) strongly associate with alarm-calling antshrikes (genus Thamnomanes), which act as sentinel species. Up to 70 species join these flocks, presumably following antshrike behavioral cues. Since flocks in this region of the Amazon are exclusively led by a single antshrike species, this provides a unique natural system to compare differences in sentinel quality between flocks. We simulated predation threat by flying three species of live trained raptors (predators) towards flocks to compare sentinel probability to (1) produce alarm calls, and (2) encode information about magnitude and type of threat within such alarm calls. Our field experiments show significant differences in the probability of different sentinel species to produce alarm calls and distinguish predators. This variation may have important fitness consequences and shape the "landscape of fear" for eavesdropping species.

Zika Virus Disease in Children in Colombia, August 2015 to May 2016

BACKGROUND

Children are considered a potentially vulnerable population for Zika virus infection. However, data on paediatric Zika virus infection are sparse.

METHODS

We analysed data from Colombia's national surveillance system during the 2015-2016 Zika virus outbreak on patients meeting the clinical case definition of Zika virus disease (ZVD) among children aged 1 month to 18 years to estimate incidence by demographic characteristics and characterize the occurrence of selected complications.

RESULTS

Between August 14, 2015, and May 28, 2016, there were 18 576 reported cases of postnatal ZVD among children aged 1 month to 18 years. Laboratory testing was prioritized for high-risk patients (infants, pregnant women, adults aged ≥65 years, and persons with serious co-morbidities); among 1655 that were tested by real-time reverse transcriptase polymerase chain reaction, 1207 (72.9%) were positive. The cumulative incidence of reported ZVD was 114.4 per 100 000. The incidence differed by sex, depending on age group; the largest difference was observed for 15-18 year olds, with females having a higher incidence than males (cumulative incidence ratio 2.5, 95% confidence interval 2.3, 2.7). At the time of report to the surveillance system, 631 patients (3.4%) were hospitalised and 96 (0.5%) had a report of an accompanying neurological diagnosis, including Guillain-Barré syndrome in 40 patients.

CONCLUSIONS

Only a small proportion of reported paediatric ZVD cases in Colombia were hospitalized or had reported neurological conditions following ZVD. However, the potential for some serious outcomes demonstrates the importance of preventing Zika virus infection in children.

Severe Neurologic Disorders in 2 Fetuses with Zika Virus Infection, Colombia

We report the results of pathologic examinations of 2 fetuses from women in Colombia with Zika virus infection during pregnancy that revealed severe central nervous system defects and potential associated abnormalities of the eye, spleen, and placenta. Amniotic fluid and tissues from multiple fetal organs tested positive for Zika virus.

Clinical and histopathological features of fatal cases with dengue and chikungunya virus co-infection in Colombia, 2014 to 2015

We report clinical features and histopathological findings in fatal cases with dengue (DENV) and chikungunya (CHIKV) co-infection identified at the Colombian National Institute of Health between September 2014 and October 2015. Seven such cases were documented. Dengue serotype 2 virus was identified in six cases. All patients were adults and comorbidities were present in four. Fever, arthralgia or myalgia was present in all cases. The frequency of rash, haemorrhage, oedema, and gastrointestinal symptoms was variable. Laboratory findings such as thrombocytopenia, renal failure, and leukocyte count were also inconsistent between cases. Post-mortem tissue examination documented focal hepatocellular coagulative necrosis in three cases, incipient acute pericarditis in one and tubulointerstitial nephritis in one. This study provides evidence of mortality in patients with DENV and CHIKV co-infection. Fatal cases were characterised by variable clinical and laboratory features. Evaluation of histopathology of autopsy tissues provided evidence of the pathological consequences of the disease.

Influenza virus

El virus de la influenza es un importante agente patógeno humano que causa infecciones respira-torias y una considerable morbimortalidad anual a nivel mundial. El virus puede circular esporádicamente durante brotes locales como parte de una epidemia estacional o puede generar una pandemia mundial.

[Detection of dengue virus antigen in post-mortem tissues]

The epidemiological situation of dengue has worsened over the last decade. The difficulties in preventing its transmission and the absence of a vaccine or specific treatment have made dengue a serious risk to public health, health centers and research systems at different levels. Currently, most studies on the pathogenesis of dengue infection focus on the T-cell immune response almost exclusively in secondary infections and are aimed at identifying the mechanisms involved in the development of vascular permeability and bleeding events that accompany the infection. This report describes the case of a baby girl less than 45 days of age with clinical signs of severe dengue, whose diagnosis was confirmed by reverse transcription polymerase chain reaction in post-mortem tissue samples and by the ancillary diagnostic use of immunohistochemistry, which detected viral antigens in all organs obtained at autopsy. This case highlights the importance of studying primary infections associated with severe dengue, particularly in children, who are more likely to develop the severe form of the disease without previous infection, and it further stresses the importance of a diagnosis that should not be based solely on the examination of liver tissue samples when studying the pathogenesis of the viral infection.

Chagas disease (Trypanosoma cruzi) and HIV co-infection in Colombia

Chagas disease is a complex zoonotic pathology caused by the kinetoplastid Trypanosoma cruzi. This parasite presents remarkable genetic variability and has been grouped into six discrete typing units (DTUs). The association between the DTUs and clinical outcome remains unknown. Chagas disease and co-infection with HIV/AIDS has been reported widely in Brazil and Argentina. Herein, we present the molecular analyses from a Chagas disease patient with HIV/AIDS co-infection in Colombia who presented severe cardiomyopathy, pleural effusion, and central nervous system involvement. A mixed infection by T. cruzi genotypes was detected. We suggest including T. cruzi in the list of opportunistic pathogens for the management of HIV patients in Colombia. The epidemiological implications of this finding are discussed.

Maternal mortality due to pandemic influenza A H1N1 2009 virus in Colombia

AIMS

The 2009 H1N1 pandemic illustrated the higher morbidity and mortality from viral infections in peripartum women. We describe clinical features of women who recently died of H1N1 in Colombia.

METHODS

This is a case series study that was gathered through a retrospective record review of all maternal H1N1 deaths in the country. The national mortality database of confirmed mortality from H1N1 in pregnancy and up to 42 days after delivery was reviewed during the H1N1 season in 2009. Women with H1N1 infections were confirmed by the laboratory of virology. Demographic, clinical, and laboratory data were reviewed. Statistical analyses were performed and median values of non-parametric data were reported with inter-quartile range (IQR).

RESULTS

A total of 23 H1N1 maternal deaths were identified. Eighty-three percent occurred in the third trimester. None of the mothers who died had received influenza vaccination. The median time from symptom onset to the initiation of antiviral treatment was 8.8 days (IQR 5.8-9.8). Five fatalities did not receive any anti-viral therapy. Median PaO2/FiO2 on day 1 was 80 (IQR, 60-98.5). All patients required inotropic support and mechanical ventilation with barotrauma-related complications of mechanical ventilation occurring in 35% of patients.

CONCLUSION

In Colombia, none of the women suffering H1N1-related maternal deaths had received vaccination against the disease and most had delayed or had no anti-viral therapy. Given the lack of evidence-based clinical predictors to identify women who are prone to die from H1N1 in pregnancy, following international guidelines for vaccination and initiation of antiviral therapy in suspected cases would likely improve outcomes in developing countries.

First report of human Trypanosoma cruzi infection attributed to TcBat genotype

Chagas disease is an endemic disease of the American continent caused by Trypanosoma cruzi and divided into six discrete typing units (TcI - TcVI). Nearly 10 million people harbour the infection representing a serious issue in public health. Epidemiological surveillance allowed us to detect a bat-related T. cruzi genotype (henceforth named TcBat) in a 5-year-old female living in a forest area in northwestern Colombia. Molecular tools determined a mixed infection of T. cruzi I and TcBat genotypes. This represents the first report of TcBat infection in humans; the epidemiological consequences of this finding are discussed herein.

[Morphological changes in lung tissue of victims associated with the 2009 A H1N1/v09 influenza pandemic in Colombia]

INTRODUCTION

Influenza is an acute respiratory infection that may be seasonal or pandemic. In 2009 The World Health Organization (WHO) declared an influenza pandemia; 3,876 cases and 239 deaths were reported in Colombia.

OBJECTIVE

The morphological changes in lung tissues associated with virus infection H1N1/v09 were described from autopsied victims. Materials and methods. Seventy-five cases were diagnosed by RT-PCR for influenza A H1N1/v09, of which the lungs of 20 were selected for morphological study by light microscopy, optical microscopy, high-resolution transmission electron microscopy and immunohistochemistry.

RESULTS

Of the 75 cases, 83% had viral pneumonitis and 17% alveolitis. Complications included intra-alveolar hemorrhage (66%), edema (89%), diffuse alveolar damage (2%), and bacterial co-infection (32%). Morphological changes were as follows: destruction of the alveolar epithelium and interstitium, edema, macrophages with vacuolated cytoplasm,and infiltration of polymorphonuclear leukocytes in the alveolar lumen and interstitium, vacuolization cytoplasmic type I pneumocytes and electronedense bodies in cellular debris in the alveolar lumen, and immunoreactivity of viral antigens in bronchiolar epithelial cells and alveolar infiltrate.

CONCLUSION

The low percentage of bacterial co-infection observed in these cases was a prominent feature, and suggested that the fatal result was probably not associated with secondary bacterial disease (Indicated by previous reports). The tissue lesions were attributed to tissue damage due to viral lesion, as well as the cellular and humoral inflammatory response associated with infiltration by polymorphonucleocytes and macrophages in the interstitium and alveolar lumen.

Infestation by triatomine bugs in indigenous communities of Valledupar, Colombia

OBJECTIVE

To calculate triatomine infestation indices in indigenous communities in Colombia.

METHODS

A descriptive study was carried out in 19 communities in Valledupar Municipality, Cesar Department, Colombia. During June to December, 2007, triatromine bugs were collected from their resting places in households. Taxonomic identification was made according to the keys by Lent & Wygodzinsky. An infection process in animal model and isozyme analysis of triatomine feces were performed.

RESULTS

Rhodnius prolixus showed a density index of 154.7%, for Triatoma dimidiata was 102.45%, T. maculata 109.25% and Panstrogylus geniculatus 0.3%. The mean infestation index was 40.54%, and mean Trypanosoma infection index was 9.4%. Of five hemocultures positive for T. cruzi, three were enzimatically identified as T. cruzi group I. Biopsies revealed few pathologic characteristics of infective process with these strains isolated from domiciliary triatomine bugs.

CONCLUSIONS

The high triatomine infestation indices in households and the T. cruzi infection index are evidence of active transmission of Chagas disease. The situation merits a vector control program and serological survey of the population at risk. The genetic characterization of T. cruzi strains as group I agrees with other findings on strains in this region of Colombia.

Plasticity of hippocampus following perinatal asphyxia: effects on postnatal apoptosis and neurogenesis

Asphyxia during delivery produces long-term deficits in brain development, including hippocampus. We investigated hippocampal plasticity after perinatal asphyxia, measuring postnatal apoptosis and neurogenesis. Asphyxia was performed by immersing rat fetuses with uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Caesarean-delivered pups were used as controls. The animals were euthanized 1 week or 1 month after birth. Apoptotic nuclear morphology and DNA breaks were assessed by Hoechst and TUNEL assays. Neurogenesis was estimated by bromodeoxyuridine/MAP-2 immunocytochemistry, and the levels and expression of proteins related to apoptosis and cell proliferation were measured by Western blots and in situ hybridization, respectively. There was an increase of apoptosis in CA1, CA3, and dentate gyrus (DG) and cell proliferation and neurogenesis in CA1, DG, and hilus regions of hippocampus 1 week after asphyxia. The increase of apoptosis in CA3 and cell proliferation in the suprapyramidal band of DG was still observed 1 month following asphyxia. There was an increase of BAD, BCL-2, ERK2, and bFGF levels in whole hippocampus and bFGF expression in CA1 and CA2 and hilus at P7 and P30. There was a concomitant decrease of phosphorylated-BAD (Ser112) levels. The increase of BAD levels supports the idea of delayed cell death after perinatal asphyxia, whereas the increases of BCL-2, ERK2, and bFGF levels suggest the activation of neuroprotective and repair pathways. In conclusion, perinatal asphyxia induces short- and long-term regionally specific plastic changes, including delayed cell death and neurogenesis, involving pro- and antiapoptotic as well as mitogenic proteins, favoring hippocampal functional recovery.

[Evaluation of TcH2AF-R and S35-S36 primers in PCR tests for the detection of Trypanosoma cruzi in mouse cardiac tissue]

INTRODUCTION

Heart transplant is a therapeutic option in the treatment of chagasic cardiomyopathy. For early detection of Chagas reactivation cases, the use of PCR tests using endomyocardial biopsies has been proposed. Development of an animal model will be the first step in evaluating the applicability of this approach.

OBJECTIVE

PCR tests based on the TcH2AF-R and S35-S36 primers were evaluated for the detection of T. cruzi in heart tissue of mice experimentally infected with the parasite.

MATERIALS AND METHODS

Two groups of ICR mice of 15 and 10 individuals were infected by intraperitoneal injection with 0.3 ml of PBS containing 1 x 10(6) trypomastigotes of the MHOM/CO/2001/D.A. (T. cruzi I) strain or 1 x 10(4) trypomastigotes of MHOM/BR/00/Y (T. cruzi II) strain. Parasitemia and cardiac parasitic infection were determined at 30, 60 (acute model), 100 and 150 (chronic model) days by means of histopathological examination and by PCR, using the TcH2AF-R and S35-S36 primers.

RESULTS

The histopathological findings revealed alterations in the heart and the presence of intracellular amastigotes in acute and chronic models. In contrast to parasitemia levels and histopathological analyses, S35-S36 PCR detected infections in mice that were infected with either parasite strain. TcH2AF-R PCR detected T. cruzi I-infected mice earlier and more frequently than inspection for parasitemia or histopathological examination.

CONCLUSIONS

Applying PCR tests with both primers proved superior for Chagas disease confirmation over currently standard detection methods.

[Detection of yellow fever virus by reverse transcriptase polymerase chain reaction in wild monkeys: a sensitive tool for epidemiologic surveillance]

INTRODUCTION

Yellow fever is a zoonotic infection maintained in nature by non-human primates. Appropriate surveillance with sensitive laboratory techniques is necessary to evidence viral activity in the tropical forest habitats of these primates.

OBJECTIVE

Yellow fever virus was detected in hepatic tissue samples from non-human primates by reverse transcriptase polymerase chain reaction (RT-PCR) technique using specific primers for diagnosis.

MATERIALS AND METHODS

Hepatic tissue samples were processed from five monkeys belonging genus Alouatta spp found dead in sylvatic areas of Cesar and Magdalena Provinces, Colombia, between December 2003 and June 2004. Samples were treated with lysis buffer prior to the isolation of viral RNA, which was then subjected to reverse transcriptase polymerase chain reaction (RT-PCR) using yellow fever-specific primers. Simultaneously, viral proteins were identified by immunohistochemistry on parafin-embedded hepatic tissue.

RESULTS

The PCR method amplified fragments of the expected size (424 bp) in four of the tested samples. In addition, these samples showed a positive reaction by immunohistochemistry, supporting the evidence that the virus was present.

CONCLUSION

The detection of yellow fever virus in wild monkeys was clear evidence of enzootic activity in northern Colombia. Increased probability of yellow fever transmission among human populations is indicated due to urbanization processes as a consequence of forced migration and displacement of the human populations. Molecular tests for rapid and specific detection of yellow fever in tissue samples of non-human primates is an important tool for epidemiologic surveillance. Rapid virus identification will permit the timely activation of control systems for prevention of further cases and epidemic situations.

Rocky Mountain spotted fever, Colombia

We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

Evaluation of molecular markers in hepatic metastasis of colorectal adenocarcinoma

BACKGROUND/AIMS

There were 49 patients studied, coming from The Liver Unit at the "Hospital das Clinicas da Faculdade de Medicina da USP (N=41) and from "Prof. Dr. Angelita Habr-Gama and Joaquim Gama-Rodrigues Surgery Institute", SP (N=8); all of which had hepatic metastasis of colorectal adenocarcinoma, with no evidence of concurrent metastasis in any other organs and were submitted to surgical treatment, during the period of 1992 to 2002, with the aim of analyzing the immunoexpression of the p53, ki-67, p16 and molecular markers in order to relate the disease-free period with the prognosis.

METHODOLOGY

The patient's clinical data were analyzed retrospectively for verification of information such as age, gender, size of the hepatic metastasis and/or the largest lesion, number of satellite nodules resected and compromised, margin of resection free from neoplasia.

RESULTS

The immunoexpression of the p53 was associated with the shortest period of life free from disease (p = 0.04). The proliferation marker ki-67 was not associated with the reduction of the disease-free interval and survival; the immunoexpression of the proliferation marker p16 was not associated with the reduction of disease-free period and survival, however, it was associated with hepatic metastasis synchronism. In patients who received postoperative systemic chemotherapy with 5-FU and leucovorin, the immunoexpression on the hepatic metastasis was not associated with a longer disease-free interval.

CONCLUSIONS

Molcular markers may be useful to evaluate hepatic metastasis of colorectal Adenocarcinoma.

Cell proliferation and tumor formation induced by eserine, an acetylcholinesterase inhibitor, in rat mammary gland

Environmental chemicals may be involved in the etiology of breast cancer. There is substantial evidence that breast cancer risk is associated with prolonged exposure to female hormones. Among these hormonal influences a leading role is attributed to the ovarian hormone estradiol, since breast cancer does not develop in the absence of ovaries. The rat mammary gland has special characteristics that make it an ideal organ for studying development, cell proliferation and transformation. In vivo and in vitro model systems for cell proliferation and mammary carcinogenesis have allowed morphological and biochemical analysis under different experimental conditions. The aim of this study was to examine the effect of eserine, an acetylcholinesterase inhibitor, as are the organophosphorous compounds malathion and parathion, and 17beta estradiol on cell proliferation and tumor formation that takes place in the rat mammary gland after in vivo and in vitro treatment. These studies showed that eserine and 17beta estradiol were capable of inducing carcinogenesis in the epithelium of rat mammary glands. It was found that there was a significant increase in the number of cells per duct of the 44-day-old rat mammary gland after the 10-day eserine treatment, compared to the control. A higher increase was observed in the animals treated for 10 days with eserine followed by 30-daily injections of estrogen in comparison to control animals. In 12 animals, two mammary tumors were directly developed in response to 17beta estradiol injected at 39 days of age with a latency period of 180 and 245 days, respectively. Such tumors were metastatic to the lung. These results suggest that terminal end buds are major targets related to rat mammary carcinogenesis and 17beta estradiol can be an initiator and promoter in this process.

[Outbreaks of human rabies transmitted by vampire bats in Alto Baudó and Bajo Baudó municipalities, department of chocó, Colombia, 2004-2005]

INTRODUCTION

During months May to July 2004, a rabies outbreak in the Embera community of Birrinchao, in the Purricha river basin department of Choc6 was reported with 14 human deaths. Another rabies outbreak was reported in January 2005 in the black communities of Pató and Nauca in the neighboring municipality of Alto Baudó with 3 human deaths.

OBJECTIVES

To describe the largest outbreaks of human rabies transmitted by vampire bats reported in Colombia to date. To describe the diagnostic laboratory techniques used, and the activities undertaken for the control of rabies in the area. To discuss the epidemiologic significance and public health implications of these rabies outbreaks.

MATERIALS AND METHODS

Rabies diagnosis was achieved by direct immunofluorescence, inoculation of mice and immunohistochemistry. Typing of the virus was achieved by indirect immunofluorescence using monoclonal antibodies. Rabies control activities were undertaken in Bajo Baudó consisting in a population census, human vaccination and application of antirabies sera, vaccination of dogs and cats, and application of anticoagulant to bats.

RESULTS

Four human cases were confirmed as positive for rabies in both rabies outbreaks. Another 13 rabies cases in humans were inferred by strong epidemiological links. Rabies antigenic variant 3 was identified in the samples studied. Rabies control activities were conducted for a human rabies outbreak caused by vampire bats.

CONCLUSIONS

The human rabies outbreak in Bajo Baudó has been the largest reported in Colombia. It was caused by vampire bats, showing that these animals are a threat for human health. The implementation of control strategies for this kind of epizootic outbreaks is needed in South America. It remains unknown whether there is a link between this outbreak and one reported 6 months later in the neighboring municipality of Alto Baudó.

[Hemodialysis prospective multicentric quality study]

In medicine a considerable amount of resources are used in research, but very little attention is paid to ensuring that the findings of research are implemented in routine clinical practice. This prospective study has the aim to evaluate the efficiency of some clinical management strategies (feedback, benchmarking and improving plans) on haemodialysis treatment results in 4 different dialysis centres. We collected consensus data related to haemodialysis results every 6-8 months and informed each centre about its own results (feedback) and how these related to the others(benchmarking). We designed improving plans for any bad result detected. By the end of two years of follow up, 294 patients had been included in the study. The results obtained at the end of the study had improved in comparison with those obtained at the beginning (statistically significant) for the following indicators: % of patients with Hb< 11 g/dl, % patients with Kt/v < 1.2, mean Kt/v, mean albumin, % patients with albumin< 3.5 g/dl y % patients with C reactive protein (CRP) > 5 mg/dl. No statistical changes were found in: mean erythropoietin (EPO) doses, blood pressure (BP), phosphorus plasmatic,calcium-phosphorus product, parathormone (PTHi) and vascular access distribution. We explained the absence of any improvement because of adequate start indicators in some areas (BP and vascular access), therapy with limited efficiency (calcitriol, calcium carbonate and others), lack of support resources (dietetic unit) or inadequate design/implementation of improving plans.In conclusion, our intervention illustrates that combined clinical management strategies(feedback, benchmarking and improving plans) are efficiency in improving some areas of haemodialysis treatment (anaemia, dialysis dose, nutrition and inflammation), although it does not improve calcium phosphate metabolism related indicators.

[Macrocephaly the first manifestation of glutaric aciduria type I: the importance of early diagnosis]

INTRODUCTION

The clinical manifestations of glutaric aciduria type I (GA-I) usually develop during the first two years of life as acute encephalopathic crisis leading to irreversible dystonic. Progressive macrocephaly can be an early clinical sign. We report a 9 month old patient with macrocephaly diagnosed of GA-I in the presyntomatic stage. This early diagnosis and treatment avoided the irreversible neurologic damage associated to this disease.

CASE REPORT

A 9 month old male referred to the pediatrics neurology clinic because of macrocephaly with a head circumference of 51 cm (> 97th percentle). At birth this head circumference was 37.5 cm (97th percentile) and showed rapid growth during the first 4 months of life. In the physical exam there was mild hypotonia and no other neurologic alterations with normal psychomotor development. In the work up for macrocephaly urinary organic acids were determined showing a glutaric acid: 78,000 mmol/mol creatinine (normal values: 2-10); 3-hydroxyglutaric acid: 250 mmol/mol creatinine (normal values: 1-12). Cerebral magnetic resonance (MR) performed at 12 months of age showed frontotemporal atrophy with enlargement of subarachnoid spaces, a high signal in T2 in the pallidus nucleus and subdural hematomas. Genetic analysis showed a mutation S 305 L/Q 352 X in GCDH gene. L-carnitine and riboflavin supplementation and a diet with restriction of lysine and tryptophan was started. Intercurrent illnesses were treated with intravenous fluid, glucose and L-carnitine. At 3 years and 6 month of age, he had not shown any encephalopathic crisis, he had a normal psychomotor development and no dystonia. MR shows mild temporal lobe atrophy without basal ganglia alterations.

CONCLUSIONS

In GA-I, macrocephaly is an early sign before other neurologic alterations. In patients with little or no neurological symptoms, early treatment may prevent the acute encephalopathic crisis and neurological deterioration, improving the prognosis and may also normalize the basal ganglia neuroradiological alterations. Urinary organic acid analysis should be performed in the work up of macrocephaly of unknown aetiology.

Maternal adaptation to high-altitude pregnancy: an experiment of nature--a review

A long and productive history of studies at high altitude has demonstrated that chronic hypoxia plays a key role in the aetiology of intrauterine growth restriction (IUGR) and pre-eclampsia. Susceptibility to altitude-associated IUGR varies among high-altitude populations in relation to their duration of altitude exposure, with multigenerational residents demonstrating one-third the birth weight fall present in shorter-resident groups. Higher uteroplacental blood flow during pregnancy in multigenerational high-altitude residents suggests that such population differences are due, at least in part, to differences in maternal vascular responses to pregnancy. We hypothesize that natural selection acting on hypoxia-inducible factor (HIF)-targeted or -regulatory genes has enabled maternal vascular adaptation to pregnancy in long-resident high-altitude groups. Preliminary evidence in support of this hypothesis demonstrates that the potent HIF-targeted vasoconstrictor, endothelin-1 (ET-1), is differentially regulated by pregnancy and chronic hypoxia in Andean vs European residents of high altitude. Andeans show the normal, pregnancy-associated fall in ET-1 levels previously reported at low altitude, whereas Europeans have higher ET-1 levels and little pregnancy-associated change, like pre-eclamptic women. Single nucleotide polymorphisms (SNPs) in the ET-1 gene also differ in Andeans compared with low-altitude populations. We conclude that high altitude serves as an experiment of nature for elucidating genetic factors underlying susceptibility to complications of pregnancy and fetal life. Such studies may be important for identifying persons at risk for these complications at any altitude.

[Idiopathic hypertrophic cranial pachymeningitis]

Idiopathic hypertrophic cranial pachymeningitis is an infrequent chronic inflammatory process of unknown etiology which causes thickening of the dura mater and progressive neurologic alterations due to the compression of adjacent structures. A case is presented of an adult woman with a clinical syndrome consisting of headache, progressive visual loss and bilateral optic neuropathy. The diagnosis was based upon visualization of the thickened dura mater in neuroimaging studies and the exclusion of known causes by histopathological examination. Diagnosis and follow-up of this condition are currently easier with the use of nuclear magnetic resonance with contrast medium. Biopsy of the dura mater continues to be the gold standard for the definitive diagnosis of this disease. Steroid therapy causes clinical improvement in most of the patients; however, relapses are frequent, making necessary the concomitant use of other immunosuppressive agents such as cyclophosphamide or azathioprine. Mortality is low but definitive neurologic sequelae are common.

G and P genotypes of rotavirus circulating among children with diarrhea in the Colombian northern coast

A study on the prevalence of rotavirus G and P genotypes was carried out based on 253 stool specimens obtained from children living in the Colombia northern coast region who were less than 3-years-old and who suffered from acute diarrhea. A previous study had detected the presence of rotavirus A in 90 (36.5%) of the 246 samples tested by enzyme immunoassay (EIA), and these strains were investigated in the present study. Of these, 50 strains yielded an RNA electropherotype, most of which (80.0%) had long profiles and 20.0% of which had short profiles. Genotyping of 84 positive samples indicated that 67.9% of the strains could be typed. G1 (57.9%), was the most predominant VP7 genotype, followed by G3 (21.1%), G9 (15.8%) and G2 (5.3%). Among the VP4 genotypes, P[4] (49.1%) was the most prevalent, followed by P[6] 36.4% and P[8] (14.5%). Neither G4 nor G8 nor P[9] types were detected. The most common G-P combinations were G3 P[4] (8.8%) and G9 P[6] (7.0%), followed by G1 P[4] and G1 P[8] (5.3% each). All G1 P[8] strains showed long RNA profiles, whereas G3 P[4] and G9 P[6] displayed both long and short patterns. Mixed infections involved 21.0% of strains. There was a marked diversity among strains collected, and novel strains, including G9, as well as other atypical combinations of G and P genotypes, such as G9 P[6] and G3 P[4], were found.

Rotavirus type A and other enteric pathogens in stool samples from children with acute diarrhea on the Colombian northern coast

The present study, conducted from March 1998 to July 2000, determined the etiology of acute diarrhea in 253 young children and infants from Cartagena and Sincelejo, Colombia. In 253 stool samples, the following enteric pathogens were recovered: rotavirus type A (36.6%) as the major agent, Salmonella spp (9.0%), Shigella spp (8.0%), enteric pathogenic Escherichia coli (6.0%), enteric hemorragic Esc. coli (2.8%), Providencia alcalifaciens (2.8%), Aeromonas hydrophila (2.0%), Yersinia enterocolitica (0.8%), Entamoeba hystolitica (10%), Giardia lamblia (4%), Endolimax nana (3.2%), Ascaris lumbricoides (2.8%), Ent. coli (1.2%), Balantidium coli (0.8%), Blastocystis hominis (0.8%), Dypilidium caninum (0.4%) and hook worm sp. (0.4%). Infection with more than one pathogen occurred in 96 (37.9%) patients. Rotavirus and enteric pathogenic Esc. coli were frequent. Concurrent infection by more than one parasite occurred in 18.6% of the infants. Most rotavirus infections (76.7%) occurred in infants under 12 months. Vomiting, severe dehydration and fever were frequent in children with rotavirus infection. At least one fecal marker of inflammatory diarrhea was registered in patients with bacterial infection. To our knowledge, this is first report of P. alcalifaciens associated with infantile diarrhea in Colombia and the first description of Esc. coli O157:H7 and Y. enterocolitica in our region.