Search PubMed⌕ Search

Biomedical subjects

A Figueredo

Publications and source records attributed to A Figueredo.

At least 19 recordsLinked to original sources
PubMed2006

[Microbiological isolates in patients with febrile neutropenia and hematological neoplasias].

We studied the frequency of culture isolation, type of microorganism isolated and local pattern of resistance in 309 adult febrile neutropenic inpatients with hematological neoplasm, who were hospitalized between January 1998 and December 2003, in Caracas University Hospital (Hospital Universitario de Caracas), in Venezuela. There were 576 febrile neutropenic episodes. Organisms were isolated in 41% of 940 cultures. The most common organisms involved were gram-negative bacilli (48%), followed by gram-positive cocci (35.1%), fungal (11.5%) and other agents (5.4%). Coagulase-negative staphylococci (22.4%) and Escherichia coli (13.4%) were the most isolated; 58.5% of 479 agents isolated had an antibiogram; 62.2% of coagulase-negative staphylococci and 23.1% coagulase-positive staphylococci were oxacillin-resistant. We did not find any vancomycin-resistant organisms. The gram-negative antimicrobial sensitivity for imipenem was 96.2%, cefepime 81%, and ceftazidime 57.5%. Tazobactam-piperacillin and sulbactam-cefoperazone were tested in 26% of antibiograms and had activity of 57.1% and 77.5%, respectively. Fungi were not characterized. Betalactamases producing gram-negative bacilli were found. In general, micro-biological identification and local vigilance of antibacterial resistance pattern must be done routinely in these patients, in order to improve empiric therapy guidelines.

Adult↗
PubMed2004

Interleukin-10 polymorphisms in Spanish type 1 diabetes patients.

The MHC accounts for half of the genetic susceptibility to type 1 diabetes (T1D). Evidence suggests that an imbalance in Th1/Th2 responses may play a key role in the development of autoimmune diabetes. Since interleukin-10 (IL-10) modulates immune and inflammatory responses and has been implicated in many autoimmune diseases, it seemed interesting to examine whether IL-10 polymorphisms participate in diabetes predisposition. In fact, this is the first association study investigating the role of the IL- 10 polymorphisms in susceptibility to T1D in a Caucasian population. Three promoter polymorphisms (-1082G/A, -819C/T, -592C/A) and two CA-repeat microsatellites (IL-10R and IL-10G at -4 and -1.1 kb) were tested in a case-control study with 294 T1D patients and 574 healthy controls. Our results prove a minor role of IL-10 in the autoimmune diabetes risk, although we found the same association trend with IL-10G(*)12 allele as was previously observed for multiple sclerosis and rheumatoid arthritis.

Diabetes Mellitus, Type 1↗
PubMed2000

Circulating monocytes in patients with diabetes mellitus, arterial disease, and increased CD14 expression.

Low serum concentrations of high-density lipoprotein (HDL) cholesterol and elevated levels of acute-phase reactans are frequently found in patients with non-insulin-dependent diabetes mellitus (NIDDM) and cardiovascular disease. Changes in the phenotype of circulating monocytes have been reported with both of these circumstances in nondiabetic subjects. In the present study, we explored the possibility that similar changes may occur in circulating monocytes of patients with NIDDM and arterial disease. Two groups of subjects with NIDDM were studied: patients with cardiovascular disease (n = 25) were compared with a group without cardiovascular disease (n = 26); both groups were age- and sex-matched, had the same length of diabetes duration, and degree of glycemic control. Healthy nondiabetic volunteers of comparable age and sex (n = 35) formed the control group. There was no significant difference in the numbers of the CD14+/CD16+ monocyte subpopulations between the 3 groups. However, a significant graded increase of the mCD14 intensity expression values was observed among the groups, with the highest levels in patients with NIDDM patients and the lowest in nondiabetic subjects. The serum C-reactive protein concentrations were significantly higher in the group with arterial disease compared with those without arterial disease or healthy controls. In the group of patients as a whole, relative mCD14 intensity expression was significantly correlated with HDL cholesterol levels (inversely) and with serum concentrations of C-reactive protein. Serum HDL cholesterol levels and the C-reactive protein concentrations were also significantly correlated. We concluded that the increased mCD14 intensity expression on circulating monocytes may be an important contributor to the increased inflammatory response observed in patients with NIDDM and arterial disease, and eventually, to atherogenesis.

Aged↗
PubMed2000

Isolation of hypotensive compounds from Solanum sisymbriifolium Lam.

The crude hydroalcoholic root extract (CRE) of Solanum sisymbriifolium Lam. has formerly been shown to have hypotensive activity both in normo-and hypertensive rats. Hypotensive activity-guided fractionation of the CRE was performed in anaesthetized normotensive rats, which led to the isolation of the active principles. The intravenous (i.v.) and intraperitoneal (i.p.) values of the CRE in mice were found to be, respectively, 343 and 451 mg/kg, and no lethal effect was caused by doses up to 5.0 g/kg when administered by oral route. Depression of locomotion, increase of breathing rate and piloerection was observed in a general behavior test with doses up to 200 mg/kg i.p., and 1000 mg/kg p.o., respectively. Increase in the gastrointestinal transit was found using 0.1 g/kg, whereas at doses of 0.5 and 1 g/kg, no significant activity was observed in comparison with the control mice. Hexanic and butanolic fractions induced a remarkable hypotension in anaesthetized normotensive rats in doses of 1, 5, 7.5 and 10 mg/kg i. v. Two compounds isolated from the butanolic fraction induced a significant decrease of the blood pressure, HR, amplitude of the ECG and breathing rate when injected in a dose of 1 mg/kg i.v; and both systofic and diastolic, blood pressures were affected in a proportional mode. The hypotensive effect of the two compounds were not influenced by pretreatment with atropine and propranolol; and the pressor response to noradrenaline was not affected by any of them which suggests that neither a direct muscarinic activity, beta-adrenoceptor activation nor decrease of sympathetic vascular tone (sympatholitic activity) are probably involved in the mechanism of hypotension. The present study shows that the CRE of S. sisymbriifolium contains at least two hypotensive compounds whose characterization is under way.

Animals↗
PubMed2000

Genetic characterization of soybean rhizobia in Paraguay.

The soybean is an exotic plant introduced in Paraguay in this century; commercial cropping expanded after the 1970s. Inoculation is practiced in just 15 to 20% of the cropping areas, but root nodulation occurs in most sites where soybeans grow. Little is known about rhizobial diversity in South America, and no study has been performed in Paraguay until this time. Therefore, in this study, the molecular characterization of 78 rhizobial isolates from soybean root nodules, collected under field conditions in 16 sites located in the two main producing states, Alto Paraná and Itapúa, was undertaken. A high level of genetic diversity was detected by an ERIC-REP-PCR analysis, with the majority of the isolates representing unique strains. Most of the 58 isolates characterized by slow growth and alkaline reactions in a medium containing mannitol as a carbon source were clustered with strains representative of the Bradyrhizobium japonicum and Bradyrhizobium elkanii species, and the 16S ribosomal DNA (rDNA) sequences of 5 of those isolates confirmed the species identities. However, slow growers were highly polymorphic in relation to the reference strains, including five carried in commercial inoculants in neighboring countries, thus indicating that the Paraguayan isolates might represent native bradyrhizobia. Twenty isolates highly polymorphic in the ERIC-REP-PCR profiles were characterized by fast growth and acid reactions in vitro, and two of them showed high 16S rDNA identities with Rhizobium genomic species Q. However, two other fast growers showed high 16S rDNA identity with Agrobacterium spp., and both of these strains established efficient symbioses with soybean plants.

DNA, Bacterial↗
PubMed1998

Prospectively randomized trial of postoperative adjuvant chemotherapy in patients with high-risk colon cancer.

PURPOSE: This study had two major goals: (1) to assess the effectiveness of a regimen of fluorouracil (5-FU) plus levamisole plus leucovorin as postoperative surgical adjuvant therapy for patients with high-risk colon cancer, and (2) to evaluate 6 months versus 12 months of chemotherapy. PATIENTS AND METHODS: Patients with poor-prognosis stage II or III colon cancer were randomly assigned to receive adjuvant chemotherapy with either intensive-course 5-FU and leucovorin combined with levamisole, or a standard regimen of 5-FU plus levamisole. Patients were also randomly assigned to receive either 12 months or 6 months of chemotherapy, which resulted in four treatment groups. RESULTS: Eight hundred ninety-one of 915 patients entered (97.4%) were eligible. The median follow-up duration is 5.1 years for patients still alive. There was a difference among the four treatment groups with respect to patient survival, and a significant duration-by-regimen interaction was observed. Specifically, standard 5-FU plus levamisole was inferior to 5-FU plus leucovorin plus levamisole when treatment was given for 6 months (5-year survival rate, 60% v 70%; P < .01). CONCLUSION: There was no significant improvement in patient survival when chemotherapy was given for 12 months compared with 6 months. When chemotherapy was given for 6 months, standard 5-FU plus levamisole was associated with inferior patient survival compared with intensive-course 5-FU plus leucovorin plus levamisole. These data suggest that 5-FU plus levamisole for 6 months should not be used in clinical practice, whereas 6 months of treatment with 5-FU plus leucovorin plus levamisole is effective.

Adenocarcinoma↗
PubMed1998

Treatment of congenital Chagas' disease diagnosed and followed up by the polymerase chain reaction.

In 1991 and 1992, a prenatal screening of Trypanosoma cruzi infection was carried out using ELISA and indirect immunofluorescence techniques. A total of 840 blood samples from pregnant women, obtained at the Maternity Ward of the Hospital de Clínicas, National University of Asunción (Asunción, Paraguay), and 1,022 samples from the Regional Hospital of the San Pedro Department of Paraguay were examined. It was observed that 7.7% and 10.5%, respectively, of the pregnant women were serologically positive for infection with T. cruzi. When blood samples obtained from newborns on the day of birth or, at the most, on the first few days afterwards were examined by direct microscopic observation, an incidence of congenital transmission of 3% was found. These results are consistent with those of neighboring countries. When a serologic follow-up was conducted on the newborns until six months of age, the incidence of congenital transmission reached 10%. The same incidence rate was obtained when the samples collected during the first days after birth were examined by the polymerase chain reaction (PCR). Fifty-eight infants born to seropositive mothers were followed-up, two of which were positive by direct microscopic observation at birth, and four who were PCR-positive, but microscopy-negative at birth. None of the infants were positive for IgM at birth. The infected babies were treated with benznidazole and were followed-up by serology and PCR for four years. We conclude that the PCR has a clear advantage over conventional techniques for the early detection of congenital transmission of T. cruzi infection, and for monitoring infants undergoing chemotherapy.

Animals↗
PubMed1997

Adjuvant therapy for stage III colon cancer after complete resection. Provincial Gastrointestinal Disease Site Group.

GUIDELINE QUESTIONS: Should patients with resected stage III colon cancer receive adjuvant therapy? If so, which therapy should be recommended? OBJECTIVE: To make recommendations regarding the use of adjuvant therapy in the treatment of resected stage III colon cancer. OUTCOMES: Overall survival is the primary outcome of interest. Secondary outcomes are disease-free survival and adverse effects of the treatment regimens. PERSPECTIVE (VALUES): Evidence was selected and reviewed by 4 members of the Gastrointestinal Disease Site Group (GI DSG) of the Ontario Cancer Treatment Practice Guidelines Initiative. Earlier drafts of the guideline were reviewed, discussed and approved by the GI DSG, which comprises medical and radiation oncologists, surgeons and epidemiologists. Community representatives did not participate in the development of this guideline but will participate in future guidelines development. QUALITY OF EVIDENCE: There are 3 meta-analyses, 33 published randomized controlled trials (RCTs) and 1 consensus statement. The GI DSG pooled data from 10 of the 33 RCTs that allowed for such an analysis. BENEFITS: Two of 3 RCTs reported improved survival rates with 5-fluorouracil (5-FU) plus semustine or mitomycin C (MMC) compared with no treatment (observation) after surgical resection. Three trials reported a benefit in both overall and disease-free survival with 5-FU plus levamisole compared with observation after surgery. In 2 trials, levamisole alone did not produce a survival benefit compared with observation. One trial reported improved disease-free, but not overall, survival rates with oral HCFU (1-hexylcarbamoyl-5-fluorouracil) compared with observation. In 3 trials of 5-FU plus leucovorin, disease-free and overall survival rates were improved compared with observation. Nine trials compared portal vein infusion (PVI) of 5-FU with observation after surgery. In 2 of the trials, for which data were available for stage III patients only, improved overall survival was reported. There was a trend in all studies favouring PVI. One trial reported a survival benefit for stage III and IV patients who received oral HCFU maintenance therapy for 1 year compared with no maintenance therapy. In a trial comparing MMC plus oral HCFU with MMC alone, a survival benefit was reported in the combined treatment group; however, the stages of cancer were unevenly distributed among the treatment groups. Only 1 study tested monoclonal antibody; a benefit was reported for both overall and disease-free survival. A meta-analysis of 10 trials comparing adjuvant therapy with observation in patients with stage III disease detected a significant reduction in the odds ratio (OR) for death (OR 0.69; 95% confidence interval [CI] 0.57 to 0.85), with an absolute improvement in survival of 4% to 13%. When trials were separated according to the type of treatment given, the significant ORs were for 5-FU plus either levamisole (OR 0.61; 95% CI 0.46 to 0.80) or leucovorin (OR 0.51; 95% CI 0.36 to 0.73). Three recently reported trials comparing various combinations of 5-FU plus leucovorin, with or without levamisole, showed similar improvements in disease-free and overall survival.

Chemotherapy, Adjuvant↗
PubMed1997

Adjuvant therapy for stage II colon cancer after complete resection. Provincial Gastrointestinal Disease Site Group.

GUIDELINE QUESTION: Should patients with resected stage II colon cancer receive adjuvant therapy? OBJECTIVE: To make recommendations regarding the use of adjuvant therapy in the treatment of resected stage II colon cancer. OUTCOMES: Overall survival is the primary outcome of interest. Secondary outcomes are disease-free survival and adverse effects of the treatment regimens. PERSPECTIVE (VALUES): Evidence was selected and reviewed by 2 members of the Provincial Gastrointestinal Disease Site Group (GI DSG) of the Cancer Care Ontario Practice Guidelines Initiative. The recommendations resulting from this review have been approved by the GI DSG, which comprise medical and radiation oncologists, surgeons and epidemiologists. Community representatives did not participate in the development of this practice guideline but will do so in future guidelines development. QUALITY OF EVIDENCE: There are 25 published randomized controlled trials (RCTs) and 1 meta-analysis. The GI DSG pooled data from 11 of the 25 RCTs that provided adequate data. BENEFITS: The 25 RCTs are grouped according to the type of therapy and whether the control patients received no treatment (observation) or other adjuvant therapy after resection. Because the trials usually included patients with stage II and III cancer, the complete trial results and those for a subset of patients with stage II disease were analysed. Although the overall trial results showed a survival benefit for adjuvant treatments, the benefit was not significant for stage II patients. A meta-analysis of 11 trials comparing adjuvant treatment with observation in patients with stage II cancer indicated no significant reduction in the odds ratio (OR) for death (OR 0.83; 95% confidence interval [CI] 0.62 to 1.10). The OR for death among patients receiving chemotherapy by portal vein infusion (PVI) was 0.62 (95% CI 0.35 to 1.11). HARMS: The toxic effects of 5-fluorouracil (5-FU) with either levamisole or leucovorin, or both, were mild to moderate and consisted mostly of stomatitis, diarrhea and myelosuppression; 5% of patients required hospital admission. 5-FU plus levamisole was associated with transient neurotoxic effects in 18% of patients. Toxic effects associated with PVI were mild, rare and mostly consisted of leukopenia and diarrhea; 1% of patients experienced bowel perforation. PRACTICE GUIDELINE: Adjuvant therapy is not recommended at this time for the routine management of patients with resected stage II colon cancer. Patients with stage II disease and high-risk factors (bowel obstruction, tumour adhesion, invasion, perforation or aneuploidy) have a poorer prognosis, similar to that of patients with stage III colon cancer. For individual management, these patients should be made aware of their prognosis; treatment can be considered after the uncertainty of the value of adjuvant therapy has been explained to the patient. The enrolment of patients with high-risk stage II disease in clinical trials is encouraged. Trials comparing adjuvant therapy with observation are needed and are ethically acceptable in stage II colon cancer.

Chemotherapy, Adjuvant↗
PubMed1996

Increased serum levels of IgA antibodies to hsp70 protein in patients with diabetes mellitus: their relationship with vascular complications.

We measured class-specific antibodies to the mycobacterial hsp70 protein in 67 patients with diabetes mellitus (27 type 1 and 40 type 2) with or without vascular complications. Using ELISA, the levels of IgG and IgM antibodies in the sera of diabetic patients did not significantly differ either from those of healthy control subjects or between both types of diabetes, regardless of gender, disease duration, HbA1 level, or type of vascular complication. In patients with type 2 diabetes, the mean serum IgA levels were significantly higher than those in their matched controls [274(71) mg/dl vs 208(88) mg/dl; P < 0.01]. In this group of patients, the IgA antibody titer was significantly correlated to the serum IgA level (r = 0.334; P < 0.01). Serological autoimmunity (IgG or IgM type) to hsp70 protein is common in both the normal and the diabetic population. The increased IgA levels and anti-hsp70 IgA titers in the sera of diabetics suggest a possible role of IgA in the pathogenesis of the vascular complications of diabetes mellitus.

Adult↗
PubMed1996

Trypanosoma cruzi: polymerase chain reaction-based detection in dried feces of Triatoma infestans.

PCR was employed to detect Trypanosoma cruzi DNA in Triatoma infestans dry fecal spots collected on filter papers. Both insects fed on experimentally infected monkeys and insects collected in a Paraguayan endemic area for Chagas' disease were examined. When the insects fed on a chronically infected monkey with low parasitemia as revealed by direct microscopic observation (DMO), T. cruzi was detected in the insect feces by PCR as soon as 2 days postfeeding. When the same experiment was performed on monkeys with parasitemia levels below the limit of detection by DMO, the degree of positivity found through PCR-Southern hybridization, applied on Day 8 postfeeding, was superior to that obtained through xenoculture. These results suggest that PCR can be used to speed the xenodiagnosis results with great sensitivity. On the other hand, when applied to the feces of triatomines collected in the field, 84% were positive by PCR-Southern hybridization, whereas only 26% were positive by DMO. Therefore, PCR could also be applied to the monitoring of the infection status of triatomines which infest rural dwellings by examining only the feces left on paper sensors hung on the walls of the houses.

Animals↗
PubMed1995

The influence of age on the management of anal cancer.

The standard treatment for anal cancer is combination chemo-radiotherapy. Management decisions such as radical chemotherapy, resective surgery for poor response or relapse are frequently modified by age-associated comorbid factors. Between 1980 and 1990, our regional cancer center serving a population of 1.8 million saw 78 patients with squamous carcinoma of the anus. We have compared patients who were younger than 65 years (n = 38) with those older than 65 years (n = 38). The mean +/- standard deviation age for the whole cohort was 65 +/- 12 years, with a ratio of 2 females to each male presenting. Fewer of the elderly age group had major surgery (26% vs. 42%) (p = 0.03), and fewer suffered no toxicity (42% vs. 26%) (p = 0.03). However, 61% of the under-65-year age group are alive disease-free vs. 26% of the elderly group (p = 0.03). Similarly, only 18% of the under-65-year group died with disease compared with 37% of the elderly group (b = 0.03). For the series as a whole, the crude mortality was 42%, with 27% dying of their disease. The stage distribution, and the amount of radiotherapy or chemotherapy administered was not age-specific, but younger patients had more surgery and suffered more toxicity, with a greater proportion remaining alive and disease-free, and fewer dying of their disease. These data suggest that a more aggressive multi-modality approach in the elderly may improve disease response and survival.

Age Factors↗
PubMed1993

Mortality in retired coke oven plant workers.

A previous study on 536 retired coke oven plant workers in Lorraine Collieries (France) reported an excess of deaths from lung cancer (standardised mortality ratio (SMR) = 251) compared with the French male population. Occupational exposures during working life were retraced for each subject, but the number of deaths during the observation period (1963-82) was small, and smoking habits were known only for dead subjects. In 1988, the cohort was re-examined (182 deaths occurred between 1963 and 1987) and smoking habits were determined for all the subjects. This study confirmed the excess of lung cancer (SMR = 238, p < 0.001). It showed an excess of mortality from all causes (SMR = 141, p < 0.001), overall cancers (SMR = 133, p < 0.05), and cardiovascular diseases (SMR = 133, p < 0.05). A significant excess of deaths was found for subjects who worked near the ovens for all causes (145, p < 0.01), lung cancer (SMR = 252, p < 0.01), colon cancer (SMR = 381, p < 0.05), and cardiovascular diseases (SMR = 155, p < 0.05). A significant excess mortality was also found from all causes (176, p < 0.05) and stomach cancer (SMR = 538, p < 0.01) in subjects who worked in byproducts, from lung cancer (SMR = 433, p < 0.001) in those in the workshops, and from cirrhosis of the liver and alcoholism (SMR = 360, p < 0.01) in those underground; but, due to small numbers, these figures were not robust. An excess of mortality from all causes (SMR = 163, p<001), lung cancer (SMR = 228, p<0.05) and cardiovascular diseases (SMR = 179, p<0.01) was shown also for non-exposed or slightly exposed subjects. The fact that, on the whole, mortality of various exposed groups was similar to that of non-exposed or slightly exposed workers may be explained in part by the selection at hiring and the healthy worker effect. As an increased risk of lung cancer was noted among subjects who worked in the old generations of plant compared with the other workers (although the relative risk was not significant) it is concluded that the role of occupational hazards could not be excluded.

Cardiovascular Diseases↗
PubMed1993

Plasma C3d levels and ischemic heart disease in type II diabetes.

OBJECTIVE--To test the hypothesis that the complement system may be activated in patients with type II diabetes and CAD. RESEARCH DESIGN AND METHODS--The plasma C3d concentration was measured in 106 type II diabetic patients and 25 nondiabetic control subjects. The patient group was subdivided according to AER, and the groups were adjusted for age, sex, and known duration of diabetes. For the assignment to a given subgroup, normoalbuminuria was defined as AER < 15 microns/min, microalbuminuria as AER 16-250 micrograms/min, and macroalbuminuria as AER > 250 micrograms/min. The presence or absence of coronary disease was assessed through clinical examination, ECG, and coronary angiography. An RIA system was used for measurement of urinary albumin levels, and the plasma C3d concentrations were measured by ELISA. RESULTS--Within each of the AER-defined subgroups, the plasma C3d levels were significantly higher in patients with IHD than in those without. Thus, in the normoalbuminuric group, plasma C3d levels were 16.3 AU/ml (95% CI 13.9-19) in patients with IHD vs. 11.6 AU/ml (95% CI 10.5-12.7) in those without (P < 0.001). The corresponding data for the microalbuminuric and macroalbuminuric groups were 21.8 (95% CI 18.1-26.3) vs. 13.6 (95% CI 12.3-15.1) and 31.6 (95% CI 24.9-40) vs. 17.5 (13.6-22.6) AU/ml (P < 0.01), respectively. Patients with IHD also had significantly higher plasma C3d levels than normal control subjects, regardless of AER subgroup. A multiple logistic regression analysis demonstrated an association between the plasma C3d concentration and IHD and AER. CONCLUSIONS--Activation of the complement system may play a role in the development of macrovascular disease in type II diabetes.

Albuminuria↗
PubMed1992

Physiological functions of hydroperoxidases in Rhodobacter capsulatus.

Rhodobacter capsulatus J1 has two hydroperoxidases: a catalase-peroxidase and a peroxidase. A mutant strain, AH18, that had no catalase-peroxidase was isolated. The growth rate under aerobic and photosynthetic conditions, respiration, superoxide dismutase and peroxidase activities, and pigment content of the mutant were similar to those of the wild type. AH18 was more susceptible to killing and to inhibition of nitrogenase by H2O2 but not by molecular oxygen. The incidences of spontaneous mutations were similar in both strains. Viable counts in aerobic but not anaerobic cultures of AH18 started to decline as soon as the cultures reached the stationary phase, and the rate of cell death was much higher in AH18 than in the wild type. It is inferred that the peroxidase provides protection against H2O2 in log-phase cells and that the catalase-peroxidase provides protection under the oxidative conditions that prevail in aging cultures. This protective function might be related to the dual activity of the latter as a catalase and a peroxidase or to its capacity to oxidize NADH, NADPH, and cytochrome c.

Acetylene↗
PubMed1992

Polymerase chain reaction-based detection of Trypanosoma cruzi DNA in serum.

DNAs prepared from chagasic patients' sera were amplified by the polymerase chain reaction using oligonucleotide primers which anneal specifically to a highly repetitive sequence of Trypanosoma cruzi nuclear DNA. Samples from both acutely and chronically infected patients yielded positive results by this method. No significant difference was observed when either whole blood or serum samples of the patients were used. These results indicate that serum instead of whole-blood samples could be used for polymerase chain reaction-based detection of T. cruzi in field studies without the need of applying any special chemical treatment to the specimens. This would represent a considerable advantage due to the easier handling and transportation of serum as compared with whole-blood samples, especially in tropical climates.

Adolescent↗