Awake versus sleep endoscopy: personal experience in 250 OSAHS patients.

Identifying the site of obstruction and the pattern of airway change during sleep are the key points essential to guide surgical treatment decision making for Obstructive Sleep Apnoea-Hypopnoea Syndrome in adults. In this investigation, 250 cases were retrospectively analyzed in order to compare the pharyngolaryngeal endoscopic findings detected in the awake state, with those obtained in drug-induced sedation, by means of the Sleep Endoscopy technique. All endoscopic findings have been classified according to the semi-quantitative NOH staging. The awake and sedation NOH resulted identical in 25% of the cases only, while the discrepancies involved the oropharyngeal and hypopharyngeal sites, respectively in about 33% and 50% of the patients. The laryngeal obstructive role detected during sedation in almost 33% of the cases was both unforeseen and relevant, with all the consequent implications in the treatment choices particularly for the surgical cases.

The METIS project for generalist ultrasonography.

Reorganization of the community healthcare system and the growing presence of group practices in the field of general medicine have increased the demands placed on primary-care medicine, in terms of the skills required and the level of responsibility. Satisfying the need for rapid, effective primary-care solutions to the health problems of citizens is easier thanks to technological and medical advances that provide high level equipment at costs within the reach of general practitioners (GPs). In the near future, trained GPs equipped with appropriate diagnostic scanners will be able to handle up to 40% of the requests of ultrasound examinations of each primary-care group (each PCG includes approximately 15,000-20,000 citizens). The Italian Federation of General Practitioners (Federazione Italiana dei Medici di Medicina Generale - FIMMG) and its Scientific Society, METIS, have organized national courses for those GPs who wish to become generalist ultrasonographers, in a joint effort with the two most important Italian scientific societies of imaging, the Italian Society of Ultrasonology in Medicine and Biology and the Italian Society of Medical Radiology.

Human immunodeficiency virus infection: personal experience in changes in head and neck manifestations due to recent antiretroviral therapies.

Both the incidence and prevalence of human immunodeficiency virus infection are increasing in the world. Diseases of ENT districts are more frequent in human immunodeficiency virus-infected patients and involve all the otolaryngological sites. The otorhinolaryngological manifestations in association with HIV infection are mainly atypical, so common in the clinical practice, really aspecific and very frequent in ENT daily routine (such as sinusitis, otitis, etc.) and, therefore, immunodeficiency may not be suspected. In other cases, ENT evidence is more peculiar or unusual, such as opportunistic infections, rare neoplasm and tumours with an unusual course, giving a very high suspect of a human immunodeficiency virus-related infection. The most frequent malignant neoplasm is Kaposi's Sarcoma which is extremely rare in non-human immunodeficiency virus-infected subjects; the second most frequent is non-Hodgkin's lymphoma with 50% in extranodal sites (oral and maxillary sinus). Following a review of the literature, modifications caused by current antiretroviral treatment on head and neck manifestations of human immunodeficiency virus infection have been evaluated. Highly active antiretroviral therapy is a new therapeutic strategy, based on poly-chemo-therapeutic schemes, providing simultaneously two or more anti-retroviral drugs. We have used highly active antiretroviral therapy in human immunodeficiency virus infection since 1997, substituting previous mono-chemotherapy based on Zidovudine or Didanosine alone. Highly active antiretroviral therapy is extremely efficient in reducing the viral load of human immunodeficiency virus and increasing CD4+ T-lymphocyte count. These biological effects are associated with an improvement in immune functions. To evaluate the effects of highly active antiretroviral therapy on otorhinolaryngological manifestations in human immunodeficiency virus infection, we performed a retrospective study on 470 adults, observed over 14 years (1989-2002) and constantly receiving the same treatment, with follow-up from 7 to 80 months. A total of 250 subjects underwent mono-antiretroviral chemotherapy (1989-1996), while 220 underwent highly active antiretroviral therapy (1997-2002). The results of the retrospective study showed that highly active antiretroviral therapy has greatly improved the control of the immune-deficiency (increasing the range of CD4+), reducing the number of otorhinolaryngological manifestations (also tumours). On the other hand, 2 patients presented sudden unilateral hearing loss following treatment: toxicity due to association of new drugs cannot be excluded.

Role of skin-lined tracheotomy in obstructive sleep apnoea syndrome: personal experience.

Permanent tracheotomy was the first surgical procedure proposed for the treatment of severe obstructive sleep apnoea syndrome and is still the only surgical option that ensures, even in very severe cases, complete elimination of apnoea and, in turn, clinical remission. Improved knowledge of the causes of obstructive sleep apnoea syndromes and the increasing therapeutic options (instrumental, medical and surgical) have resulted in cases requiring tracheotomy as the only indispensable therapeutic option becoming more rare. At present, the only indications are in very occasional conditions of life-threatening obstructive sleep apnoea syndromes and in patients on whom continuous positive airway pressure is not tolerated or is not effective (severe deoxygenation or hypercapnia, severe respiratory disorder index, severe obstructive sleep apnoea syndrome-related arrhythmias, severe excessive daytime sleepiness, heart diseases or ischaemic encephalopathy exacerbated by obstructive sleep apnoea syndromes, obstructive pneumopathy exacerbated by obstructive sleep apnoea syndromes, severe obstructive sleep apnoea syndromes with few chances of resolution with other surgical procedures or failure of the latter). Moreover, it is the only therapeutic solution in rare nocturnal laryngeal stridor due to multisystemic atrophy (in which obstructive sleep apnoea syndrome is due to nocturnal laryngospasm of neurologic origin). Therapeutic tracheotomy must be permanent (tracheostomy) and, therefore, preferably carried out with a specific technique (skin-lined tracheotomy), able to guarantee greater stability, less risk of granulation tissue, wider opening of the tracheostomy, sufficient reversibility. In our experience, very few patients (10 cases) withsleep disorder breathing have been submitted to skin-lined tracheotomy. Of these, the majority were submitted to surgery for severe apnoea due to nocturnal laryngospasm on account of multisystemic atrophy (n = 7), while only 3 cases of obstructive sleep apnoea syndromes were submitted to skin-lined tracheotomy, i.e., 0.7% of the 424 patients operated on for obstructive sleep apnoea syndrome and 1.7% of the 175 operated on for severe, or very severe, obstructive sleep apnoea syndromes (RDI > 40). Skin-lined tracheotomy was not followed by important complications and expected results were achieved with immediate disappearance of daytime symptoms and considerable improvement in nocturnal apnoea. Besides sleep-related disorders, numerous clinical situations with indications for a permanent tracheotomy may benefit from the skinlined technique, such as severe laryngeal or tracheal stenoses, laryngeal diplegias, miasthenia gravis, lateral amyotrophic sclerosis, intractable aspiration, severe emphysema.

Temporary tracheotomy in the surgical treatment of obstructive sleep apnea syndrome: personal experience.

Aim of the study is a retrospective analysis on the use of temporary tracheotomy in our snoring surgery experience. From September 1996 to April 2002, 1103 snoring surgery procedures have been carried out on various sites of the upper airways in 530 patients (mean age 50 years, 81% males) prevalently related to severe Obstructive Sleep Apnea Syndromes (33%). Of these patients, 472 (89%) were operated upon under general anaesthesia, whereas 58 (11%) received local anaesthesia. Of the 472 patients operated upon under general anaesthesia, 17 (3.6%) underwent temporary tracheotomy, which in 10 (2.1%) were programmed and only in 7 (1.5%) were non-programmed, having been performed in 2 cases in an emergency setting, in 3 cases in an urgency setting due to respiratory obstruction immediately after removal of intubation and in 2 cases in conditions of urgency, due to respiratory obstruction occurring during post-operative hospitalisation (both performed within 6 hours of regaining consciousness). The only complication observed was a brief laryngeal diplegia, a complication, moreover, not reported in the literature. No criteria exist concerning indications for temporary tracheotomy programmed according to the type of surgery on the hypopharynx; personal experience reveals that: a) temporary tracheotomy is frequently necessary after genioglossus advancement (3/10 operated upon for genioglossus advancement not associated with a programmed temporary tracheotomy); b) temporary tracheotomy is rarely necessary after hyoid suspension (1/98 patients being submitted to hyoid suspension not associated with programmed temporary tracheotomy). Temporary tracheotomy should, in our opinion, be taken into consideration in snoring surgery techniques, particularly in the presence of the not infrequent urgency or emergency situations occurring in patients with Obstructive Sleep Apnea Syndromes. With the use of temporary tracheotomy, no deaths occurred in the present study population.

[Semont maneuver vs. particle repositioning maneuver: comparative study]. / Manovra di Semont vs. Particle Repositioning Maneuver: studio comparativo.

In the present study 80 consecutive cases of PPV of the posterior semicircular canal are presented, with the purpose to evaluate the effectiveness of the treatment and to analyze the secondary Ny and re-test as indicators of the effectiveness of the therapeutic maneuver. The patients were treated in 40 cases with Particle Repositioning Maneuver (PRM) and in the other 40 with the Semont Maneuver, in an attempt to determine the secondary Nystagmus induced during treatment and any residual Paroxysmal Positional Nystagmus (PPNy) upon repetition of the Hallpike positioning after 15 minutes (re-test). Recovery was achieved in 80% of cases after the first session and in 95% of cases with the third session. PRM seemed to be slightly more effective. Secondary liberating Ny was frequently evoked (80%) and was reliable (75%) with the Semont Maneuver, while PRM yielded the liberating Ny in only 25% of cases, with lower reliability (70%). Reliability of the re-test with the Hallpike maneuver was high (80%) and the difference between the two techniques was negligible (78% in PRM and 85% in Semont). In conclusion, in terms of indicators of effectiveness, the Semont liberating Maneuver appears better in that it combines high therapeutic effectiveness (75% recovery in a single session) with a like percentage of liberating Ny (80%): this makes it possible to reserve the re-test and repetition of the therapeutic maneuver, performed during the same session, only in those cases that do not present liberating Ny (20% of cases). On the other hand, when the PRM is used, it appears better to rely on the high likelihood of effectiveness (85% in a single session) and then review the case directly at the next check-up rather than perform the Hallpike re-test in all cases that did not present the liberating secondary Ny (75%). In this way it is possible to select a small number of patients (22%) that still show PPNy (positive re-test) and for whom the therapeutic maneuver must be repeated.

Long-term effects of a nationwide control program on the seropositivity for Trypanosoma cruzi infection in young men from Argentina.

Unselected nationwide cohorts of Argentine men 18 years of age summoned for military service were tested for antibodies to Trypanosoma cruzi each year from 1981 to 1993. After an initial screening using indirect hemagglutination test, the positive sera were retested by titrated indirect hemagglutination and immunofluorescence antibody tests at 39 laboratories or at the national reference center in Buenos Aires. Nearly 1.8 million men were examined for T. cruzi antibodies using the same standardized procedures under a quality assurance program. The prevalence of seropositivity for T. cruzi decreased significantly from 5.8% in 1981 to 1.9% in 1993, but the decrease was not homogeneous among provinces within each region or constant over time. Prior to the nationwide control campaign initiated in 1961-1962, 15 provinces had high (> 20%) percentages of houses with domiciliary infestation by Triatoma infestans bugs, which decreased to nine provinces in 1982, and four provinces in 1992. The observed decrease in the prevalence of seropositivity for T. cruzi may be mostly attributed to the spraying with insecticides to eliminate the domiciliary populations of Triatoma infestans. The lack of a sustainable triatomine surveillance program set a limit to the decrease of seropositivity rates and prompted a revised strategy based on community participation.

[Effectiveness indices in "Particle Repositioning Maneuver" by Parnes and Price-Jones]. / Indicatori di efficacia nella "Particle Repositioning maneuver" di Parnes e Price-Jones.

The Parnes and Price-Jones "Particle Repositioning Maneuver" (PRM) was used to treat Paroxysmal Positional Vertigo (VPP) in 36 consecutive cases, studying both any induced secondary nystagmus and any persistent Paroxysmal Positional Nystagmus (PPNy) upon repetition of the Hallpike positioning after 15 minutes (re-test). The purpose of the study was to evaluate the ability to use secondary Ny and the retest to predict maneuver effectiveness. Although the PRM was quite effective (PPNy disappeared in 86% of the cases after a single session), the low observation frequency reduced the feasibility of using secondary Ny. On the other hand the systematic introduction of the Hallpike re-test into clinical practice does not offer the desired cost/benefit ratio because of the time required to prevent false negatives due to PPNy fatigue. In fact, secondary Ny was only evoked in 12 out of 36 cases (33%) and of these only 9 out of 36 (25%) presented direction congruous with canalolith release (liberating Ny). The predictive value of evoked liberating Ny appeared further reduced by the persistence of PPNy upon subsequent re-testing in two cases and in one case by the persistence of the disorder upon follow-up. The Hallpike test appears a more reliable indicator of effectiveness as it proved in agreement with subsequent clinical findings in 80% of the cases. The present results lead one to conclude that, when using PRM in cases where no secondary liberating Ny was found (75%), we should rely on the high effectiveness of this procedure (86% of the cases resolved in a single session) rather than perform a Hallpike retest. Thus it is possible to select a small number of patients (22%) still presenting PPNy (positive retest) and requiring repetition of the therapeutic maneuver.

Diagnostic role of videothoracoscopy in mediastinal diseases.

OBJECTIVE: In order to assess the role of videothoracoscopy in the diagnosis of mediastinal diseases, we report a retrospective analysis of 52 cases of mediastinal biopsy performed with this technique. METHODS: Between January 1992 and December 1996 52 patients (39 men and 13 women, mean age 53 +/- 29 years) with mediastinal lesions were referred to our department for videothoracoscopic biopsy. There were eight lesions in the anterior mediastinum, while the remaining 44 were in the middle (25 right and 19 left). The adenopathies were solitary or located in positions not within reach of the mediastinoscope, or combined with pulmonary nodules or diffuse pulmonary diseases. RESULTS: The procedure was performed from the right side in 30 cases and from the left side in 22. In nine cases the complete excision of the mass was achieved. In the eight patients with pulmonary disease a wedge resection was carried out at the same time. Diagnosis was achieved in all cases of mediastinal and lung disease (100%). No conversion to open thoracotomy and no intraoperative complications occurred. The mean hospital stay after surgery was 2.3 +/- 1.3 days in the 49 (94.2%) patients with no complications. The postoperative complications consisted of one case of fatal pulmonary embolism and two cases of prolonged air leak. conclusion: This analysis shows that videothoracoscopy is an effective and reliable method of obtaining a diagnosis of solitary unilateral mediastinal lesions or of adenopathies not within reach of the mediastinoscope. In some cases it also allows the complete excision of the mass. If a procedure on the lung such as a wedge resection is needed, it can be performed at the same time. Since this is a strictly unilateral procedure, it cannot be used in routine preoperative lung cancer staging.

[Clinical features and diagnosis of mucocutaneous leishmaniasis in patients of an endemic area in Salta]. / Caracteristícas clínicas y diagnóstico de la leishmaniasis mucocutanea en pacientes de un área endémica de Salta.

A total of 39 patients with a clinical diagnosis of mucocutaneous leishmaniasis, in an endemic area for leishmaniasis in Salta, Argentina, were examined between June 1990 and December 1992. Of these cases, 87% (34/39) presented the cutaneous simple form, 10.3% the cutaneous multiple form and 2.6% the mucosal form. Lesions were more frequently located in legs and arms (71.8%), followed by trunk and multiple location (10.3%). Of the patients, 43% were housewives, students or children, suggesting that the infection could be contracted in the domestic or peridomestic environment. Of 39 patients diagnosed, in 22 (56.4%) the parasite was found. Direct microscopy (smear) permitted a diagnosis in 13 (59.4%) of these 22 patients. Among these, 5 (22.7%) had positive diagnosis by culture, and 9 (40.9%) by inoculation in hamsters. Ten parasite isolates (45.4%) were obtained. The smear is recommended as a diagnostic method for epidemiological surveillance due to the sensibility demonstrated herein and its easy application in the endemic area. The time of clinical evolution, from the appearance of the lesion up to the detection of the patient by Sanitary Agents, was approximately 90 days. This would be related to the frequency of the visits, usually every 3 months. Only one of 30 treated patients had a relapse at 6 months, due to non fulfillment of the treatment.

Leishmania (Viannia) braziliensis: biological behavior in golden hamsters of isolates from Argentine patients.

This study reports intraspecific variations of native isolates of Leishmania (Viannia) braziliensis from patients with leishmaniasis from Salta, Argentina. These isolates induced skin lesions in golden hamsters, initially showing rapid development, reaching their largest size between 28 and 35 days postinfection (PI). Thereafter, the infections were self-limiting and total regression was observed at 80-150 days PI. The majority of the native isolates were characterized by low infectivity in the experimental animals, and a classic pattern of dissemination to systemic organs was established. However, unusual features for L. braziliensis were displayed by two isolates; one showed evidence of high infectivity in hamsters characterized by a short prepatent period and larger, severe and persistent lesions at the inoculation site. The other isolate, of low infectivity, showed cutaneous metastasis and recurrent systemic dissemination in the same animals, suggesting dissociation between infectivity and pathogenicity. Metastasis has been frequently described in hamsters infected with L. (V) guyanensis and L. (V) panamensis, but not in infections induced by L. (V) braziliensis, as was observed in this study. Active and/or regressive histopathologic lesions were observed, depending on the stage of the infection. An exudative and mixed inflammatory pattern with microabscesses and necrotic areas was observed during early infection, while well-defined granulomas and collagen formation were the predominant features detected at a later time. Amastigotes were easily detected in the tissues, although in low numbers. Schaumann bodies were always detected. The characterization of the unique features of these native isolates, and the verification of their reproducibility in vitro and in vivo will be useful tools in tests related to immunoprophylaxis and chemotherapy.

Chemoembolization in liver malignant involvement. Experiences on 17 cases.

INTRODUCTION: Liver invasion is the major cause of organ failure in patients with primary liver cancer and metastatic large bowel cancer. Furthermore it causes high morbidity in many other carcinomas. The normal liver presents a double circulation: 75% from portal circulation and 25% from hepatic artery. In malignant primary and secondary lesions the blood support is given by hepatic artery. Antineoplastic drugs mixed to selectively injecting embolic particles, such as polyvinyl alcohol and gelatin powder (Gelfoam), can be injected to infarct tumors and to obtain a therapeutical advantage. Chemoembolization using an emulsion of Lipiodol ultra-fluid (LUF) and drugs is a recent tool in liver regional therapy. LUF has been shown to be taken up hepatocellular carcinoma and retained for a long period of time in the tumor bed. Chemoembolization causes massive shrinkage due to ischemia and increasing the local drug intensity and drug exposure. Our study reports the results of multi-agents chemoembolization (MACHEM) in 17 patients bearing massive liver involvement. MATERIAL AND METHODS: From January 1988 we treated 17 patients (5 HCCs, 7 large bowell carcinomas, 1 gastric cancer, 1 ocular melanoma, 1 pancreas, 1 soft tissue sarcoma, 1 carcinoid) using a transfemoral approach to cannulate the celiac axis and then the hepatic artery. The catheter was advanced into the vessel responsible for the majority of the tumor blood supply and a mixture of Gelfoam, radiopaque contrast media, followed by chemotherapy (mitomycin 10 mg/sqm, cisplatin 20 mg/sqm, epirubicin 20 mg/sqm) mixed to LUF was injected until vascular stasis occurred. After chemoembolization, analgesics and anti-pyretics were administered. Liver function tests were monitored daily. RESULTS: Objective tumor regression was observed in 11 out 15 full evaluable patients; the median duration of survival was 9.5 months. Within 8 weeks shrinkage, due to development of necrosis, appeared in the tumors. One patient with high levels of 5-HIAA due to carcinoid, demonstrated more than 75% decreasing in urinary excretion. In 6 patients out 8 with CEA elevation a clear reduction was documented as well in 2 HCCs out 5 with alfa-fetoprotein elevation. DISCUSSION: The palliation of HCC and metastatic liver disease have been extremely disappointing. Systemic chemotherapy produces in HCC a response rate of no more than 20% and does not increase the median survival. Venook obtained 24% of PRs and liquefaction in 35 out 50 HCC treated with chemoembolization. Some results have been also demonstrated in the treatment of metastatic liver tumors by Carrasco, Daniels and Modiano. Moertel stressed that chemoembolization could be incorporated in the initial management of carcinoid. Because of the difference in chemoembolization protocols it is difficult to compare the relative efficacy of this tool, although encouraging response rates have been reported in palliation of bulky tumors. In our study Gelfoam given before LUF and antineoplastic agents mixture produce a distal arteriolar occlusion and this would facilitate the migration of the polychemotherapy emulsion toward the tumor. Our MACHEM program has been shown to have significant activity even in heavily pretreated patients with an acceptable toxicity. We conclude that hepatic arterial chemoembolization will be improved by mean of better combination of chemotherapy with embolizing agents in well selected patients.

[The correlation of bacteriobilia/wound infections in elective biliary surgery]. / Correlazione bactobilia/infezioni della ferita in chirurgia biliare d'elezione.

The authors report their experience concerning the cultural study of bile samples taken during elective biliary surgery. All the operations were carried out after a randomized preoperative antibiotic prophylaxis. Among the 138 cases examined the presence of surgical infections (wound infection) was taken into account. A lack of correlation between the germs present in the bile and those isolated from samples of complicated cases, was registered. However, the Authors emphasize that, although antibiotic prophylaxis gives a reduced percentage of postoperative infections, it is unable to sterilize the bile.

[Aztreonam and clindamycin in short-term antibiotic prophylaxis in colorectal surgery: results of a multicenter studies]. / Aztreonam e clindamicina nella profilassi antibiotica a breve termine in chirurgia colorettale: risultati di uno studio policentrico.

The Authors studied the effects of a short-term prophylaxis (Aztreonam + Clindamycin) administered to 259 patients operated on for colo-rectal diseases. Thirteen wound sepsis (5.15%) and 49 different infections (19.44%) occurred in this group of patients. The study confirms the link between P.N.I. greater than 50 and the incidence of wound infections. The incidence of urogenital sepsis was correlated with the catheterization period (greater than 6 days), operative time (greater than 200 min.), hospitalization (greater than 12 days) and age (greater than 70 years). General tolerance to the antibiotics was good.

Monoclonal antibodies against the flagellar fraction of epimastigotes of Trypanosoma cruzi: immunoprotection against metacyclic trypomastigotes obtained by immunization of mice with an affinity-purified antigen.

Subcellular fractions of Trypanosoma cruzi (epimastigotes) were assayed in their capacity to induce protective or aggressive effects in experimental animals. The flagellar fraction showed the best immunoprotective properties without tissular aggression. Monoclonal antibodies were prepared from mice immunized with this fraction. One of them, FCH-F8-4, was able to neutralize the infectivity of bloodstream trypomastigotes, to produce complement-mediated lysis on cell culture-derived trypomastigotes and to recognize the surface of trypomastigotes and epimastigotes by immunofluorescence. FCH-F8-4 reacted in Western blotting with several epimastigote proteins ranging from 50 to 150 kDa, showing a more intense reactivity with 4 bands while it reacted with two molecules on trypomastigote preparations (15 and 48 kDa). Purified antibody was coupled to CNBr-activated Sepharose and used to purify antigens from epimastigote extracts. These antigens were used to immunize BALB/c mice in the presence of Bordetella pertussis as adjuvant. Animals were protected against a challenge with 10(3) metacyclic forms of T. cruzi (Tulahuén strain). Only 40% of immunized mice presented detectable parasites in blood after challenge. Parasitemia decreased 90% in relation to controls in those animals. Survival of immunized mice was 100% in all immunoprotection experiments. These results suggest that the epitope recognized by FCH-F8-4 present in the purified antigens keeps the protective characteristics of flagellar fraction and could be a candidate for the development of a vaccine against T. cruzi infection.

[Esophago-jejunal anastomosis using an end-to-end anastomosis stapler. Clinico-radiologic study of early complications in 75 cases]. / L'anastomosi esofago-digiunale con E.E.A. Stapler. Studio clinico-radiologico delle complicanze precoci su 75 casi.

Personal experience with 75 consecutive cases of terminolaterale oesophagojejunal anastomosis by EEA Stapler is reported. A total of 6 intraoperative technical problems were encountered (8%) and consisted either of incomplete suturing of the anastomosis or stapling of the jejunal wall. Postoperative radiology revealed 5 dehiscences (6.6%) and 1 stenosis (1.33%). One patient with dehiscence died (1.33%) of septic complications. One dehiscence of the afferent jejunal stump and minor pleuropulmonary complications were observed in 3 cases. After a brief review of the literature, it is concluded that oesophagojejunal anastomosis by EEA Stapler produces a low incidence of postoperative complications such as the dehiscence, stenosis or bleeding.

Monoclonal antibodies against the flagellar fraction of epimastigotes of Trypanosoma cruzi: complement-mediated lytic activity against trypomastigotes and passive immunoprotection in mice.

Trypanosoma cruzi, the causative agent of Chagas' disease, is widely spread in Central and South America. The present report describes three monoclonal antibodies (mAbs) directed against the flagellar fraction of epimastigotes (Ffe) of the parasite, Tulahuén strain. The three mAbs were of IgG1 isotype. Indirect immunofluorescence assays revealed that the three mAbs bind to epimastigotes, the FCH-F8-1 and -3 bind to blood trypomastigotes (BT) and FCH-F8-1 is the only one that binds to amastigotes. Three different proteins of the parasite were recognized by the mAbs in immunoprecipitation assays: an 85 kDa of BT with the FCH-F8-1 mAb, a 40 kDa of Ffe with the FCH-F8-2 mAb, and a 90 kDa of Ffe and of BT with the FCH-F8-3 mAb. Positive complement mediated lysis (CML) of BT and metacyclic forms, obtained from the insect vector feces, were shown by the FCH-F8-1, while FCH-F8-3 only showed CML against the metacyclic trypomastigotes. FCH-F8-2 did not mediate any CML activity. Passive transference of the mAbs to BALB/c mice conferred protection, in terms of survival, ranging from 50 (FCH-F8-2 and -3) to 80% (FCH-F8-1) against a challenge with 1 X 10(3) BT. These results suggest that FCH-F8-1 may be a useful tool to purify proteins in order to investigate their role in immunoprotection experiments.