Comparison of indirect immunofluorescence test for measles antibodies with haemagglutination inhibition and plaque neutralization tests

Indirect Immunofluorescence (IFA), Plaque Reduction Neutralization (PRN) and Haemagglutination Inhibition (HI) tests for measles antibodies were carried out in 197 sera obtained from umbilical cord and vaccinated children. The IFA was also applied to blood samples collected with filter paper. IFA results demonstrated that the test is relatively simple to perform, with good reproducibility for different antigen lots. Good correlation was obtained between IFA, PRN and HI antibody titers. Better correlation was demonstrated with IFA and PRN than with HI and PRN tests. Sensitivity of IFA in detecting antibody was less effective than PRN, however more effective than HI using rhesus monkey red blood cells. PRN antibody titers over 100 were detected by IFA but not by HI (9.7% with negative results). IFA may be of considerable practical use and able to substitute HI in Seroepidemiological surveys and to evaluate vaccine efficacy. It also can be simplified by employing filter paper collected samples.

HEMAGGLUTINATION TEST FOR THE DIAGNOSIS OF HUMAN NEUROCYSTICERCOSIS: DEVELOPMENT OF A STABLE REAGENT USING HOMOLOGOUS AND HETEROLOGOUS ANTIGENS

A hemagglutination (HA) test was standardized using formalin- and tannin-treated gander red blood cells sensitized with a total salt extract of C. cellulosae (HA-Cc) and an antigenic extract of Cysticercus longicollis (HA-Cl) vesicular fluid. A total of 61 cerebrospinal fluid (CSF) samples were assayed, 41 from patients with neurocysticercosis and 20 from a control group, which were, respectively, reactive and non-reactive to ELISA using C. cellulosae. The CSF samples from the control group did not react and 35 (85.4%) and 34 (82.9%) CSF samples from patients were reactive to the HA-Cc and HA-Cl tests, respectively. The reagents ready for use were stable up to 6 months when stored at 4°C in 50% glycerol. The present results confirm that the reagent using Cysticercus longicollis stabilized with glycerol can be used as an alternative in the immunological diagnosis of neurocysticercosis

Thermostability of heterophile antibodies from human sera infected with Schistosoma mansoni and geo-helminths: an immuno-metric statistical analysis

Antibody in human sera that induces lysis of sheep erythrocytes in hemolytic assay was investigated. The present study showed that the presence in serum of the thermostable cytolytic anti-sheep red blood cells antibodies is dependent on the Schistosoma mansoni infection, and this is more frequent in adults than in children. The thermostable characteristic of hemolysins in normal sera was not dependent on the presence of Ascaris lumbricoides, Trichuris trichiura or hookworm geo-helminths. Further, thermostable complement-activating heterophile antibodies were noticed in children in association with massive number of S. mansoni eggs. The results were obtained by using the z- and the chi-square tests. The z-test allows us to formulate a one-sided alternative, i.e., a tendency of one of the attributes. On the other hand, the chi-square test analyzes the independence between attributes by using a contingency table. Besides the obtained results being interesting in the field of schistosomiasis mansoni, they can provide a new insight into the use of statistics in medical science.

Sharing of antigens between Plasmodium falciparum and Anopheles albimanus

The presence of common antigens between Plasmodium falciparum and Anopheles albimanus was demonstrated. Different groups of rabbits were immunized with: crude extract from female An. albimanus (EAaF), red blood cells infected with Plasmodium falciparum (EPfs), and the SPf66 synthetic malaria vaccine. The rabbit's polyclonal antibodies were evaluated by ELISA, Multiple Antigen Blot Assay (MABA), and immunoblotting. All extracts were immunogenic in rabbits according to these three techniques, when they were evaluated against the homologous antigens. Ten molecules were identified in female mosquitoes and also in P. falciparum antigens by the autologous sera. The electrophoretic pattern by SDS-PAGE was different for the three antigens evaluated. Cross-reactions between An. albimanus and P. falciparum were found by ELISA, MABA, and immunoblotting. Anti-P. falciparum and anti-SPf66 antibodies recognized ten and five components in the EAaF crude extract, respectively. Likewise, immune sera against female An. albimanus identified four molecules in the P. falciparum extract antigen. As far as we know, this is the first work that demonstrates shared antigens between anophelines and malaria parasites. This finding could be useful for diagnosis, vaccines, and the study of physiology of the immune response to malaria.

FATAL DISSEMINATED CRYPTOCOCCOSIS WITH RENAL INVOLVEMENT IN AN HIV-INFECTED PATIENT

SUMMARY Introduction: We present a fatal case of disseminated cryptococcosis in a young man whose diagnosis of HIV infection was made at the time of admission to the emergency room. Case report: The patient was a twenty-three-year-old man, with a history of daily fever during one month associated with diarrhea, weight loss, headache, vomiting and generalized seizures. He also had a history of diabetes mellitus, alcoholism and drug addiction. Upon physical examination the patient was pale, disoriented and had periods of agitation. White blood cells count was 3,440/mm3 (5% lymphocytes), hemoglobin was 10g/dL, platelets were 83,000/ mm3. Creatinine was 0.7 mg/dL; urea 19 mg/dL; Na, K, and liver enzymes were within normal limits. Lactic dehydrogenase was 494 IU/L. Cerebrospinal fluid (CSF) analysis revealed 10 white blood cells/mm3 (58% neutrophils, 31% lymphocytes, 11% monocytes) and 2 red blood cells/mm3. India ink test revealed six Cryptococcus yeasts/mm3. CSF glucose was 122 mg/dL and protein was 36 mg/ dL. VDRL test was negative and anti-HIV test was positive. Intravenous hydration, insulin, phenytoin, fluconazole, pyrimethamine, sulfadiazine, folinic acid, and amphotericin B were started. The patient did not improve and became obtunded and hypotensive. He was intubated and put on mechanical respiration. He received vasoactive drugs and died less than 24 hours after admission. A postmortem examination was performed and revealed disseminated cryptococcosis, with severe involvement of the kidneys. Conclusion: Cryptococcosis, as a rule, is a systemic disease that affects mostly immunocompromised individuals, especially patients with AIDS. When diagnosed late in its course it has a very high mortality.

South american rattlesnake venom: its hemolytic power

The hemolytic power of rattlesnake venom (Crotalus durissus terrificus) was Studied. A high percentage of sample with negative hemolytic power was detected when sheep red blood cells were used. A large number of venoms with hemolytic power, though with a low hemolysis percentage, were detected when liquid, recently extracted venom was used. When crystallized venom was used under the same experimental conditions, a higher percentage ofpositivityfor hemolysis was obtained. When the results obtained on agar plates were compared to those obtained in test tubes, a large number of animals with a higher percentage of hemolysis were detected, though this value was not proportional to the number of animals showing positive plate hemolysis. When the hemolytic power of these venoms was tested on human red blood cells, a large percentage of animals with venoms having a low hemolytic power was also detected. Hemolytic power was much greater when human red blood cells were tested with crystallized venom. The preparation of red blood cells also had an important effect and the use of red blood cells from defibrinated blood is recommended. We conclude that rattlesnake venom has hemolytic power that increases when the venom is crystallized. Red blood cells should be properly preparedfor the lysis reactions. We suggest that the lytic power of the venom is related to venom concentration and to the purity of its fractions.

Clinical and laboratory alterations in dogs naturally infected by Leishmania chagasi

INTRODUCTION: Canine visceral leishmaniasis (CVL) is a zoonotic disease with different clinical manifestations. Parasitism often occurs in bone marrow, but changes have been observed in peripheral blood and serum biochemical parameters. The aim of this study was to evaluate the hematological and biochemical parameters in dogs naturally infected by Leishmania chagasi. METHODS: Eighty-five adult dogs of both sexes and various weights and ages from the Zoonosis Control Center of Fortaleza (CCZ) were used, selected by immunofluorescence assay (IFA) and considered positive with IFA titers greater than 1:40 and by visualizing amastigotes of Leishmania chagasi in smears obtained by bone marrow aspiration. The dogs (n = 85) were grouped according to clinical signs: negative (CN = 7), subclinical (CS = 10), and clinical (CC = 68). Blood samples were collected for determination of hematological and biochemical serum values. The experimental protocol was approved by the CEUA/UECE. RESULTS: The most frequent clinical signs were cachexia (77.9%), keratitis (61.8%), and lymphadenopathy (55.9%), and 86.8% of the animals showed more than one clinical sign characteristic of CVL. In CC were observed reductions in red blood cells (63%), hematocrit (72%), and hemoglobin (62%), as well as leukocytosis (33%), neutropenia (28%), thrombocytopenia (50%), uremia (45%), hyperproteinemia (53%, p<0.05), hypergammaglobulinemia (62%, p<0.01), and hypoalbuminemia (58%). CONCLUSIONS: Animals with the clinical form of the disease demonstrate hematological and biochemical changes consistent with anemia, uremia, hyperproteinemia, and hyperglobulinemia, which present themselves as strong clinical markers of visceral leishmaniasis associated with the signs previously reported.

Widespread hematogenous metastases and Trousseau's syndrome in gastric adenocarcinoma

A case of widespread hematogenous metastases and Trousseau's syndrome is reported in a 40 year-old white housewife with gastric cancer, presenting subdural hematoma, ecchymoses, epistaxis, stomach and uterine bleeding. After undergoing hematoma drainage, she was unsuccessfully treated with platelets, red blood cells, plasma cryoprecipitate transfusions, and antibiotics. Necropsy disclosed gastric ring-signet adenocarcinoma invading the serous layer, with massive disseminated intravascular coagulation and systemic neoplastic embolism. Multiple old and recent hyaline (rich in fibrin and platelets) microthrombi, and tumor emboli were observed in the bone marrow, meninges, liver, lungs, kidneys, lymph nodes, adrenals, thyroid, heart, pancreas, and ovaries (Krukenberg tumor).

Respiratory characteristics of Hoplostenum littorale (Siluriformes, Callichthyidae)

Hematological parameters, intraerythrocytic phosphates, hemoglobin, and whole blood Bohr effect of the South American armored catfish Hoplostenum littorale were studied during different seasons of the year. In addition, the degree of dependence on air breathing was determined for this species. The hematological parameters presented seasonal variations, which were not correlated to oxygen, temperature, and water level oscillations. Five anodic hemoglobin fractions were detected in starch gel electrophoresis. In addition to ATP, GTP and Fe-GTP being detected, 2,3-DPG was also detected in red blood cells of H. littorale. The latter is an intraerythrocytic phosphate characteristic to red blood cells of mammalians. The increased production of 2,3-DPG could be associated with decreasing Hb-O2 affinity and both features could be related to environmental temperature increase. Whole blood Bohr effect was influenced by water temperature. This study confirms H. littorale to be continuous and not obligate air breather, under all dissolved oxygen level conditions.

Comparative study on hematological parameters of farmed matrinxã, Brycon amazonicus Spix and Agassiz, 1829 (Characidae: Bryconinae) with others Bryconinae species

The aim of this study was not only to determine the red blood cells parameters, thrombocyte and leukocyte counts in farmed Brycon amazonicus (matrinxã), to compare these parameters among Bryconinae species from literature, and also to investigate the presence of special granulocytic cells in these fish. The results of the blood cells parameters here established for farmed B. amazonicus, a species of great economic importance in Brazilian aquaculture, could help a better understanding of the blood features in natural populations of this Amazon species. Blood parameters varied between Bryconinae species investigated, mainly the red blood cell counts, hemoglobin, hematocrit and mean corpuscular volume (MCV). The presence of the blood granulocytes, neutrophils and heterophils in matrinxã suggest that both leukocytes can be a characteristic for Bryconinae family. Furthermore, it indicates that the existence of special granulocytic cells in the blood of Bryconinae species from literature is an artifact, and this was herein discussed.

Surgical myocardial revascularization without extracorporeal circulation

OBJECTIVE: To assess the immediate postoperative period of patients undergoing myocardial revascularization without extracorporeal circulation with different types of grafts. METHODS: One hundred and twelve patients, 89 (79.5%) of whom were males, were revascularized without extracorporeal circulation. Their ages ranged from 39 to 85 years. The criteria for indicating myocardial revascularization without extracorporeal circulation were as follows: revascularized coronary artery caliber > 1.5 mm, lack of intramyocardial trajectory on coronary angiography, noncalcified coronary arteries, and tolerance of the heart to the different rotation maneuvers. RESULTS: Myocardial revascularization without extracorporeal circulation was performed in 112 patients. Three were converted to extracorporeal circulation, which required a longer hospital stay but did not impact mortality. During the procedure, the following events were observed: atrial fibrillation in 10 patients, ventricular fibrillation in 4, total transient atrioventricular block in 2, ventricular extrasystoles in 58, use of a device to retrieve red blood cells in 53, blood transfusion in 8, and arterial hypotension in 89 patients. Coronary angiography was performed in 20 patients on the seventh postoperative day when the grafts were patent. CONCLUSION: Myocardial revascularization without extracorporeal circulation is a reproducible technique that is an alternative for treating ischemic heart disease.

The ribonucleic acid content of some mammalian erythrocytes

RNA was determined in red blood cells of man and other mammals. Our report is based on 41 determinations. Red blood cells of rat showed the highest values in comparison with the blood cells of guinea pig, rabbit, horse and sheep which showed the lowest values, and man with intermediate ones. The method used was a combination of Schimidt and Thanhauser and Schneider extractions with the final reactions of pentose with the orcinol reagent colorimetrically measured.

Decay accelerating factor (DAF) as the host antigen with protective activity to complement killing of schistosomula

The acquisition of host antigens by Schistosoma mansoni was studied by evaluating the resistance of schistosomula to the complement attack mediated by lethal antibody. Schistosomula cultured for 24 hours with intact human erythrocytes (N-HuE) or ghosts of any type of ABO or Rh blood group, showed a marked resistance to complement damage. Sheep red blood cells, pronase-treated N-HuE or erythrocytes from patients with paroxysmal nocturnal hemoglobinuria, which are complement-sensitive cells, were unable to protect schistosomula. Schistosomula protected by N-HuE became again susceptible to complement killing after incubation with a monoclonal antibody anti-DAF. These results indicate that, in vitro, host DAF from N-HuE can be acquired by schistosomula surface in a biological active form that protects the parasite from the complement lesion.

Human babesiosis in Europe

Human babesiosis in Europe came to medical attention in 1957 and until now 19 cases have been reported, most of them due to Babesia divergens. The onset of the disease is characterized by hemoglobinuria, high fever and renal failure ensue rapidly. The patients were generally asplenic and resident in a rural area. Intraerythrocytic pleomorphic parasites (1-3 µm) observed in stained thin blood smears are essential for Genus diagnosis. Parasitemia varyed from 5 to 80% of red blood cells. Massive blood exchange transfusion (2-3 blood volumes) followed by intravenous clindamycine (3-4 times daily) and oral quinine (600 mg base, 3 times daily) were successfully used in the treatment of three recent cases. Splenectomised individuals should be aware for prevention.

The Pf332 gene codes for a megadalton protein of Plasmodium falciparum asexual blood stages

We characterized the Plasmodium falciparum antigen 332 (Ag332) which is specifically expressed during the asexual intraerythrocytic cycle of the parasite. The corresponding Pf332 gene has been located in the subtelomeric region of chromosome 11. Furthermore, it is present in all strais so far analyzed and shows marked restriction length fragment polymorphism. Partial sequence and restriction endonuclease digestion of cloned fragments revealed that the Pf332 gene is composed of highly degenerated repeats rich is glutamic acid. Mung been nuclease digestion and Northern blot analysis suggested that Pf332 gene codes for a protein of about 700 kDa. These data were further confirmed by Western blot and immunoprecipitation of parasites extracts with an antiserum raised against a recombinant clone expressing part of the Ag332. Confocal immunofluorescence showed that Ag332 is translocated from the parasite to the surface of infected red blood cells within vesicle-like structures. In addition, Ag332 was detected on the surface of monkey erythrocytes infected with Plasmodium falciparum.