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Biomedical subjects

C A Martins

Publications and source records attributed to C A Martins.

At least 19 recordsLinked to original sources
PubMed2000

Epidemiology of bloodstream infections at a cancer center.

CONTEXT: Cancer patients are at unusually high risk for developing bloodstream infections (BSI), which are a major cause of in-hospital morbidity and mortality. OBJECTIVE: To describe the epidemiological characteristics and the etiology of BSI in cancer patients. DESIGN: Descriptive study. SETTING: Terciary Oncology Care Center. PARTICIPANTS: During a 24-month period all hospitalized patients with clinically significant BSI were evaluated in relation to several clinical and demographic factors. RESULTS: The study enrolled 435 episodes of BSI (349 patients). The majority of the episodes occurred among non-neutropenic patients (58.6%) and in those younger than 40 years (58.2%). There was a higher occurrence of unimicrobial infections (74.9%), nosocomial episodes (68.3%) and of those of undetermined origin (52.8%). Central venous catheters (CVC) were present in 63.2% of the episodes. Overall, the commonest isolates from blood in patients with hematology diseases and solid tumors were staphylococci (32% and 34.7%, respectively). There were 70 episodes of fungemia with a predominance of Candida albicans organisms (50.6%). Fungi were identified in 52.5% of persistent BSI and in 91.4% of patients with CVC. Gram-negative bacilli prompted the CVC removal in 45.5% of the episodes. Oxacillin resistance was detected in 26.3% of Staphylococcus aureus isolates and in 61.8% of coagulase-negative Staphylococcus. Vancomycin-resistant enterococci were not observed. Initial empirical antimicrobial therapy was considered appropriate in 60.5% of the cases. CONCLUSION: The identification of the microbiology profile of BSI and the recognition of possible risk factors in high-risk cancer patients may help in planning and conducting more effective infection control and preventive measures, and may also allow further analytical studies for reducing severe infectious complications in such groups of patients.

Adolescent↗
PubMed2000

Transforming growth factor beta1 ameliorates intestinal epithelial barrier disruption by Cryptosporidium parvum in vitro in the absence of mucosal T lymphocytes.

Exposure to oocysts of the protozoan Cryptosporidium parvum causes intestinal epithelial cell dysfunction in vivo and in vitro, but effective means by which mucosal injury might be prevented remain unclear. We examined the ability of transforming growth factor beta1 (TGF-beta1)-a cytokine synthesized and released by cells in the intestine-to preserve the barrier function of human colonic epithelia when challenged with C. parvum oocysts and then studied the mechanisms involved. Epithelial barrier function was monitored electrophysiologically, receptors for TGF-beta1 were localized by confocal microscopy, and TGF-beta1-induced protein kinase C activation was detected intracellularly by translocation of its alpha isozyme. TGF-beta1 alone enhanced intestinal epithelial barrier function, while exposure to C. parvum oocysts (> or =10(5)/monolayer) markedly reduced barrier function to < or =40% of that of the control. When epithelial monolayers were pretreated with TGF-beta1 at 5.0 ng/ml, the barrier-disrupting effect of C. parvum oocysts was almost completely abrogated for 96 h. Further investigation showed that (i) the RI and RII receptors for TGF-beta1 were present on 55 and 65% of human epithelial cell line cells, respectively, over a 1-log-unit range of receptor protein expression, as shown by flow cytometry and confirmed by confocal microscopy; (ii) only basolateral and not apical TGF-beta1 exposure of the polarized epithelial monolayer resulted in a protective effect; and (iii) TGF-beta1 had no direct effect on the organism in reducing its tissue-disruptive effects. In exploring mechanisms to account for the barrier-preserving effects of TGF-beta1 on epithelium, we found that the protein kinase C pathway was activated, as shown by translocation of its 80-kDa alpha isozyme within 30 s of epithelial exposure to TGF-beta1; the permeability of epithelial monolayers to passage of macromolecules was reduced by 42% with TGF-beta1, even in the face of active protozoal infection; and epithelial cell necrosis monitored by lactate dehydrogenase release was decreased by 50% 70 h after oocyst exposure. Changes in epithelial function, initiated through an established set of surface receptors, likely accounts for the remarkable barrier-sparing effect of nanogram-per-milliliter concentrations of TGF-beta1 when human colonic epithelium is exposed to an important human pathogen, C. parvum.

Animals↗
PubMed1998

Risk factors for bloodstream infections at a cancer center.

A hospital-based matched case-control study was conducted in order to identify risk factors for the development of bloodstream infections in adult hospitalized patients. Between January 1993 and December 1994, 264 episodes of bloodstream infection were evaluated. Significant variables identified by univariate analysis were included in a multivariate model that showed that central venous catheter [odds ratio (OR), 6.71], poor performance status (OR, 3.40), weight loss (OR, 2.47), hematologic diseases (OR, 2.24), and previous antimicrobial therapy (OR, 2.12) independently influenced the outcome. The knowledge of modifiable risk factors is useful in the development of strategies that may contribute to the prevention of bloodstream infections.

Adolescent↗
PubMed1998

Risk index for prediction of surgical site infection after oncology operations.

INTRODUCTION: Several studies have shown that surgical site infections represent most hospital-acquired infections, with the major impact being on average hospital stay and cost of hospitalization. METHODS: To develop a risk model for prediction of surgical site infections in cancer patients undergoing operative procedures and identify those with high probability of infection we performed a prospective cohort study in a tertiary cancer care hospital in Rio de Janeiro, Brazil. Risk factors were studied in single and multivariate analyses. RESULTS: Over a 24-month period, 1205 patients underwent operations for malignant disease. The overall surgical site infection rate was 17.3%. A multivariate stepwise logistic regression model identified six independent predictive risk factors: contaminated and infected operations, surgical duration greater than 280 minutes, male sex, prior radiotherapy, American Society of Anesthesiology class III to V, and antimicrobial prophylaxis not according to protocol. On the basis of individual risk scores, two groups of patients were identified: a low-risk (score < or = 8; surgical site infection rate 10%) and a high-risk group (score > or = 9; surgical site infection rate 33.6%; relative risk 3.4; 95% confidence interval 2.6 to 4.4). CONCLUSION: The oncology risk model allowed for the identification of a high-risk score group of patients and implementation of a more efficient and selective intervention program.

Brazil↗
PubMed1998

Fungemia in cancer patients in Brazil: predominance of non-albicans species.

The objective of this study was to characterize the epidemiology of candidemia in cancer patients in the city of Rio de Janeiro, Brazil. An 18-month survey of fungemia in patients with cancer was undertaken in three Hospitals in Rio de Janeiro. Forty-three episodes of candidemia were identified in 43 patients, 43 of which were episodes of candidemia; in ten case the strains were not available for further identification of species and were excluded from this analysis. The overall distribution of fungi causing fungemia was: Candida albicans (5), Candida tropicalis (16), Candida parapsilosis (6), Candida guilliermondii (4), Candida lusitaniae (1) and Candida stellatoidea (1). Antifungal prophylaxis had been administered before the episode of fungemia in only six patients (18.2%): oral itraconazole in three patients and oral nistatin, low dose intravenous amphotericin B and oral fluconazole in one patient each. There was no difference in the presence of risk factors, clinical characteristics or in the outcome between albicans and non-albicans species, nor between Candida tropicalis and other non-albicans species. There was a clear predominance of non-albicans species, regardless of the underlying disease, antifungal prophylaxis or the presence of neutropenia.

Brazil↗
PubMed1997

Nosocomial infections in an oncology intensive care unit.

INTRODUCTION: Treatment of cancer has contributed to a growing number of immunocompromised patients with life-threatening nosocomial infections (NI). High mortality with considerable cost is observed when they are admitted to the intensive care unit (ICU). Few studies on infection control and surveillance have been undertaken in this population group. METHODS: All patients treated at a six-bed medical-surgical oncology ICU for > 48 hours were prospectively observed for the development of an NI and the influence of device utilization on infection rates. The analysis used the standard definitions of the National Nosocomial Infection Surveillance System Intensive Care Unit surveillance component. RESULTS: From September 1993 through November 1995, 370 infections occurred in 623 patients during 4034 patient-days, for an overall rate of 50.0 per 100 patients or 91.7 per 1000 patient-days. Pneumonia (28.9%), urinary tract infections (25.6%), and bloodstream infections (24.1%) were the main types of infection. The most common microorganisms isolated were Enterobacteriaceae (29.7%), fungi (22.2%), and Pseudomonas aeruginosa (13.2%). The median device utilization ratios were 0.63, 0.83, and 0.86 for ventilator, indwelling urinary catheter, and central venous catheter, respectively. The highest median device-specific associated infection rate was 41.7 for ventilator. The median for the average length of stay was 8.8 days, and the average severity of illness score was 4.0. There was a strong positive correlation between the overall NI patient rate and device utilization (r = 0.56, p < 0.01), average severity of illness score (r = 0.54, p < 0.01), and average length of stay (r = 0.67, p < 0.01). No correlations were statistically significant when patient-days were used in the denominator. Among the devices only the number of central venous catheter days was significantly correlated with infections (r = 0.51, p = 0.01). The NI patient-day rates were progressively higher the longer the patients stayed in the ICU. CONCLUSIONS: The high rates reported in this study may reflect a combination of several factors related to the underlying illness, neutrophil count, and exposure to invasive procedures. The adjusted infection rates described here provide specific surveillance data for further interhospital comparisons and also to assess the influence of invasive medical interventions, allowing the implementation of preventable measures to control infections.

Brazil↗
PubMed1997

Fungaemia caused by Hansenula anomala--an outbreak in a cancer hospital.

Yeasts belonging to the genus Hansenula are rarely encountered as the cause of infection in clinical practice. A wide spectrum of infections caused by these fungi can be seen, ranging from asymptomatic fungaemia to severe disease. We describe an outbreak of 24 cases of infection due to H. anomala in an oncological hospital in Rio de Janeiro, Brazil. The median age of the patients was 11 years, of whom 54.2% were female; 91.7% of the Hansenula fungaemia occurred in the haematology unit. The most frequent primary disease diagnosis was leukaemia (62.5%), and all of those infected had had a central venous catheter or peripheral venous catheter and had been treated previously with broad-spectrum antibiotics. Numerous other risk factors were observed in our cases: previous use of steroids, chemotherapy, radiation therapy and neutropenia (data not shown). No deaths could be attributed to Hansenula.

Brazil↗
PubMed1996

Risk factors for infectious complications after abdominal surgery for malignant disease.

BACKGROUND: The emergence of nosocomial infection as a serious complication after intraabdominal operations for cancer prompted us to identify major independent risk factors associated with postoperative infection. METHODS: Risk factors were studied in single and multivariate analyses. Variables considered were remote infection, antimicrobial prophylaxis, preoperative stay, chemotherapy, radiotherapy, weight loss, elective versus emergency operation, wound class, duration of operation, drains, sex, age, and physical status. RESULTS: During 24 months, 236 patients were entered in the study. The overall postoperative infection rate was 45.7%; the surgical site infection rate was 22.4%. Multivariate analysis identified three independent variables: duration of operation longer than 5 hours (odds ratio 6.41, 95% confidence interval 3.28 to 12.54), presence of remote infection at operation (odds ratio 3.76, 95% confidence interval 1.76 to 8.03), and preoperative stay longer than 22 days (odds ratio 2.03, 95% confidence interval 1.04 to 3.95). The relative risk of infection increased from 3.0 when one risk factor was present to 7.3 when all three risk factors were present. CONCLUSIONS: The predictive power of our final multivariate risk index clearly groups these patients according to differing risk for postoperative infection. This classification contributes substantially to the effectiveness of infection control strategies to prevent the occurrence of postoperative infection in the high-risk population of patients with cancer.

Abdominal Neoplasms↗
PubMed1995

Successful treatment of catheter-related fusarial infection in immunocompromised children.

Fusarium infection is increasingly reported in immunocompromised patients. The role of central venous catheters as potential portals of entry for Fusarium is possibly underestimated. Four cases of catheter-related fusarial infection in children with acute leukemia or a solid tumor are described. These patients had an excellent response to removal of the central venous catheter and treatment with amphotericin B.

Amphotericin B↗
PubMed1995

Cryptosporidium and cryptosporidiosis.

The tiny, iodine- and chlorine-resistant protozoan oocysts of Cryptosporidium parvum, long recognized by veterinarians, have become increasingly noted as a cause of watery diarrhea in developed and developing countries throughout the world. For immunocompromised patients, particularly those with AIDS, this diarrhea can be severe and life-threatening. Clovis Martins and Richard Guerrant here discuss the increasing recognition of this important pathogen in immunocompetent patients as well, and outline new challenges to improved water treatment, immunologic and antiparasite chemotherapy.

Journal Article↗
PubMed1995

Randomized trial comparing oral ciprofloxacin plus penicillin V with amikacin plus carbenicillin or ceftazidime for empirical treatment of febrile neutropenic cancer patients.

Aminoglycoside-containing combination therapy has been the standard empirical approach for febrile neutropenic cancer patients. With the advent of the broad-spectrum oral fluoroquinolones, it is now possible to evaluate an initial empirical alternative therapy. A prospective randomized study was conducted comparing oral ciprofloxacin plus penicillin V (group A) with amikacin plus carbenicillin or ceftazidime (group B). Main criteria for eligibility were febrile patients with solid tumor or nonlymphoblastic lymphoma, a Zubrod PS equal to 1 or 2, no diarrhea, mucositis, or long-term central venous catheter. A total of 108 consecutive neutropenic febrile episodes were randomized (5 exclusions); 55 episodes were assigned to group A and 48 to group B. Most febrile episodes were of unknown origin. There were 10 microbiologically documented episodes with two cases of bacteremia. Both regimens were well tolerated. Oral regimen was substantially cheaper than parenteral regimen. Treatment success without regimen modification was 94.5% for group A and 93.8% for group B (p = .86; CI -0.08-0.10). Oral therapy with ciprofloxacin and penicillin V is a safe alternative to standard parenteral therapy in this low-risk group of neutropenic patients, with unquestionable cost containment.

Administration, Oral↗
PubMed1995

Correlation of lactoferrin with neutrophilic inflammation in body fluids.

We have reported that lactoferrin, a 77-kDa iron-binding glycoprotein found in secondary neutrophil granules, provides a useful marker of fecal leukocytes in fecal specimens from patients with inflammatory diarrhea (R. L. Guerrant, V. Araujo, E. Soares, K. Kotloff, A. A. M. Lima, W. H. Cooper, and A. G. Lee, J. Clin. Microbiol. 30:1238-1242, 1992). In order to determine the usefulness of this marker of neutrophilic inflammation in different body fluids, we examined blood, gingival swabs, sputum, and saliva using antilactoferrin antibodies (lactoferrin latex agglutination [LFLA]). LFLA titers in whole blood samples were < or = 1:4 in all eight samples from patients with neutropenia (absolute neutrophil count [ANC] = < 150 polymorphonuclear cells [PMNs] per microliter), < or = 1:8 in samples from 13 individuals with moderate leukocyte counts (ANC = 150 to 8,000), and 1:8 to 1:32 in samples from six patients with neutrophilia (ANC > 8,000). While the overlap precludes a useful role in the identification of neutropenia, these data confirm that lactoferrin titers of > 1:100 indeed indicate inflammation in fluid specimens. On quantitative elution of lactoferrin from gingival swabs, all 7 patients with dental plaque had titers of 1:200 to 1:400; 9 of 12 patients with clinical gingivitis had LFLA titers of 1:200 to 1:1,600, while all 7 individuals with healthy gums and teeth and 4 edentulous patients had LFLA titers of < or = 1:100. Eight purulent sputum samples had titers of > or = 1:400 (7 were 1:1,600) while 11 normal saliva samples showed titers of < or = 1:100. Lactoferrin titers in sputum, gingival swabs, and whole blood correlate with the presence of neutrophils or inflammation in these specimens and may offer a convenient rapid test for inflammatory processes.

Agglutination Tests↗
PubMed1994

Regulation of intestinal epithelial barrier function by TGF-beta 1. Evidence for its role in abrogating the effect of a T cell cytokine.

Maintenance of the integrity of the single-cell-thick intestinal epithelium as an in vivo barrier between environmental Ags and mucosal immunocytes is pivotal for health. The T cell cytokine IFN-gamma consistently disrupts this epithelial barrier in vitro, but the substances in mucosa that may be responsible for sustaining or enhancing barrier function have not been clearly identified. Therefore, we characterized the effect on the epithelial barrier of TGF-beta 1 and three prominent neuropeptides (VIP, substance P, somatostatin) by using a model system in which barrier function of a mature polar human colonic epithelial (T84) cell monolayer is reflected in 1) the electrical potential difference across the apical to basolateral surface of each cell, 2) the transmonolayer permeability to macromolecules such as horseradish peroxidase, and 3) lactate dehydrogenase release into the medium indicating epithelial cell cytolysis. Whereas T84 monolayers exposed to TGF-beta 1 alone demonstrated a modest increase in electrical resistance and barrier integrity, TGF-beta 1 showed a striking ability to reduce the capacity of IFN-gamma to disrupt epithelial barrier function. Characterization studies demonstrated that this TGF-beta 1 effect was prolonged (e.g., days) after a single exposure, progressive over the dose range 0.1 to 2.5 ng/ml, reversible with increased concentrations of IFN-gamma, and more pronounced when TGF-beta 1 exposure was to basolateral rather than to apical epithelial membranes. Macromolecular (horseradish peroxidase) penetration of epithelium was not simultaneously altered by TGF-beta 1 and epithelial cellular injury was minimal as gauged by lactate dehydrogenase release. Additional studies using a human pathogen demonstrated that TGF-beta 1 delayed and decreased the barrier disruption caused by exposure to Cryptosporidium parvum. TGF-beta 1 may be the first of a new class of cytokines that maintains and/or enhances barrier function of human enterocytes, in part by countering the effect of a T cell cytokine.

Animals↗
PubMedDate not supplied

Determinants of mortality in oncology patients colonized or infected with Staphylococcus aureus.

Oxacillin-resistant Staphylococcus aureus (ORSA) infection is an important cause of hospital morbidity and mortality. The objective of this study was to identify the main factors associated with death in patients colonized or infected with Staphylococcus aureus in a cancer center. A matched-pair case-control study enrolled all patients infected or colonized with ORSA (cases) admitted to the Hospital do Câncer in Rio de Janeiro from 01/01/1992 to 12/31/1994. A control was defined as a patient hospitalized during the same period as the case-patients and colonized or infected with oxacillin-susceptible Staphylococcus aureus (OSSA). The study enrolled 95 cases and 95 controls. Patient distribution was similar for the two groups (p > or = 0.05) with respect to gender, underlying diseases, hospital transfer, prior infection, age, temperature, heart and respiratory rates, neutrophil count, and duration of hospitalization. Univariate analysis of putative risk factors associated with mortality showed the following significant variables: admission to the intensive care unit (ICU), presence of bacteremia, use of central venous catheter (CVC), ORSA colonization or infection, pneumonia, use of urinary catheter, primary lung infection, prior use of antibiotics, mucositis, and absence of cutaneous abscesses. Multivariate analysis showed a strong association between mortality and the following independent variables: admission to ICU (OR [odds ratio] = 7.2), presence of Staphylococcus bacteremia (OR = 6.8), presence of CVC (OR = 5.3), and isolation of ORSA (OR = 2.7). The study suggests a higher virulence of ORSA in comparison to OSSA in cancer patients.

Catheterization, Central Venous↗
PubMedDate not supplied

[Hospital infections at an oncology hospital].

During 23 months, the authors analyzed 8122 records of cancer patients admitted to the National Institute of Cancer of Rio de Janeiro, Brazil. The rate of hospital infection was of 18.4 infection episodes per 100 admissions. Hospital infections were detected in 556 patients (57.7%) of the surgical department. The overall rate of purulence seen in 4194 surgeries was 10.1%, and among 2153 clean surgeries, the authors found 95 (4.4%) suppurated surgeries. The surgical wound (28.2%), the respiratory tract (19.2%), and the urinary tract (18.7%) were the major sites involved during infections episodes. Of the 319 ICU patients evaluated, 154 acquired infection after the first 72 hours, with a mortality rate of 48.7%. The hospital microbial flora was made-up mostly of gram-negative aerobic bacteria, with a high incidence of micro-organisms that resist to major antibiotics of hospital use. The percentage of positive results in blood culture tests requested was of 23.7%, with a predominance of gram-negative bacteria (50.9%) and a high percentage of gentamicin-resistant micro-organisms. Antibiotics of greater use in surgical interventions were amikacin, first generation cephalosporins, and chloramphenicol, whereas amikacin, carbenicillin, and first and third generation cephalosporins prevailed in nonsurgical treatments. The authors' experience and findings re-emphasize the need and the importance of a broad multidisciplinary understanding and suggest the need of strict action for an effective control and prevention in hospitals of developing countries.

Anti-Bacterial Agents↗