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To investigate functional changes in Trypanosoma cruzi parasites induced during their interaction with the vertebrate host, we compared the blood clearance profiles of blood forms isolated from infected normal mice (Reg-Tc) or from infected mice immunodepressed after treatment with cyclophosphamide (Cy-Tc). Parasite blood numbers were measured at various time intervals in animals injected intravenously (i.v.) with 1-2 x 10(6) T. cruzi of either isolate. In the absence of added immune sera (spontaneous clearance), Reg-Tc and Cy-Tc were cleared from blood at similar rates. However, when acute immune mouse serum (Ac-IMS) was injected i.v. 2 min after inoculation of parasites, a significant proportion of Cy-Tc only was cleared from the blood an hour later, whereas Reg-Tc were not, their clearance profile being identical to that observed in mice injected with normal mouse serum. Cy-Tc susceptibility to Ac-IMS was not the result of a toxic effect of cyclophosphamide over T. cruzi as parasites recovered from animals immunodepressed by irradiation before infection were cleared similarly by acute serum. Contrary to Ac-IMS, chronic immune mouse serum induced similar rates of disappearance of Reg-Tc and Cy-Tc from blood. Our results suggest the occurrence of T. cruzi selection or modification during the acute phase, which leads to an increased parasite resistance to the clearance properties of acute-phase antibodies.

Postinfarction ventricular septal rupture (VSR) is a high-risk complication following myocardial infarction (MI). Surgical treatment has evolved to improve an otherwise poor prognosis. Certain subsets of patients remain a formidable challenge. The presence of cardiogenic shock has consistently been found to have the highest risk. Over a 10-year period, our technique of repair has evolved from established procedures to one we believe confers superior results. Endocardial patching to viable myocardium reinforced with an epicardial patch not only corrects the shunt but maintains ventricular geometry and avoids tension on friable muscle. We report on a series of nine consecutive patients in cardiogenic shock. The operative mortality was 22%, none due to low cardiac output syndrome, shunt recurrence, or bleeding. All patients have been followed with transesophageal echocardiography at a mean period of 14 months (range 3-31 months). One patient is in New York Heart Association (NYHA) Class I, four are in NYHA Class II, and two in NYHA Class III.

After nasal provocation test in patients with allergic rhinitis, using the allergen they were sensitized to, we have observed: 1) an increase in the percentage of nasal eosinophils after 2, 3, 24 and 48 hours; 2) sneezes, mainly in the first 30 minutes; 3) nasal obstruction in the first three hours; 4) absence of rhinorrhea, but not in all the patients; and 5) no predominance of nasal, auricular and/or palatine pruritus at any time. When patients without rhinitis, or with allergic rhinitis were stimulated using a pneumoallergen they were not sensitized to, no significative increase in the nasal eosinophils percentage was found. No symptoms were observed either. So, we can conclude that nasal secretion samples, for eosinophilia percentage determination, should be taken from 2 to 48 hours after nasal provocation, and that the most frequent symptoms, which are probably related to cellular changes, are nasal obstruction and sneezes.

A voltammetric study of the oxidation of sumatriptan succinate (1:1) has been carried out at the glassy carbon electrode. This compound exhibited a single wave in Britton-Robinson buffer solutions of pH 2-11, with a maximum current at pH 5.0. The mechanism of oxidation was shown to be due to oxidation of the N-H group in the indole ring. Based on this study, a simple, rapid and sensitive voltammetric method was developed for the determination of the drug in a tablet dosage form.

From January 1980 to January 1990 all patients undergoing cardiac surgery at the Royal North Shore Hospital, Sydney, and requiring intra-aortic balloon counterpulsation (IABCP) were retrospectively reviewed. A total of 99 patients (32.6%) developed complications. Vascular/haemorrhagic complications occurred in 46 patients (15.2%); 79 patients (26%) required platelet transfusions. We have found that only a history of hypertension was predictive of an increased incidence of developing vascular complications. Surgical intervention was required in 17 patients (5.6%), or 47% of the patients who developed a vascular complication. The mortality among patients requiring IABCP was 36.6%. Intra-aortic balloon pump-related deaths occurred in 6 patients (2%). Use of the intra-aortic balloon pump can be a life-saving procedure, but it carries a significant morbidity and mortality rate. This makes it imperative to temper our indications to those patients who demonstrate a need for it.

We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transferred with one Y strain parasite and in 20% of animals transferred with one CL strain parasite). Using acute phase bloodforms, the assay proved to be more sensitive than conventional subinoculation when dealing with the CL, but not the Y strain of the parasite. With the help of this parasite detection tool, we have studied during a one year period, the evolution of subpatent parasitaemias in a group of mice which survived through chemotherapy from lethal acute phase of T. cruzi infection. Cyclophosphamide transfer assay revealed occult parasitaemias in 100% of the chronic animals, nevertheless, continuous and discontinuous patterns of positivity were observed.

Blood pressure variations of 30 insulin-dependent diabetic patients free of complications, and aged between 14-35 years have been studies, comparing their results to those from a control group formed by healthy person of the same age and physical features. Median systolic pressure of diabetic population was 120 +/- 11.07, compared to 112.90 +/- 11.31 from control group. The median diastolic pressure of diabetic population was 76.76 +/- 10.12 and 67.40 +/- 7.94 of the control group. A significant difference on systolic (p less than 0.05) and diastolic (p less than 0.001) pressures were observed in insulin-dependent diabetic patient comparing their results to those from the control group.

Acquired erythroblastopenia, or pure red cell aplasia, may appear as a complication of chronic lymphocytic leukaemia. This was the case in a 58 year-old man, diagnosed as having B-cell chronic lymphocytic leukaemia considered as stage C (III). He was treated initially with chlorambucil; two months after diagnosis the patient showed erythroblastopenia, being treated with chlorambucil-prednisone, cyclophosphamide-prednisone, prednisone alone, and intravenous immunoglobulins. No satisfactory response was achieved with any of these drugs. During a period of 28 weeks the patient received 41 units of packed red cells. Cyclosporin-A, at a 9 mg/Kg daily doses, was tested, a dramatic response being observed: after four weeks of such therapy the patient's haemoglobin reached 14.5 g/dL, and he needed no further transfusion since the beginning of this treatment.

The adsorptive voltammetric behaviour of immunoglobulin M (IgM) has been investigated at the static mercury drop electrode. The stripping process yields an analytically useful signal and the detection limit is 1.2 x 10(-10)M. The adsorptive voltammetric behaviour of IgM has been compared with that of IgG and streptavidin.

Alanine aminotransferase has been stabilized by using chemical modification with both bis(imidates) (of varying length) and succinic anhydride. The voltammetric behavior of the native enzyme and its various modified forms has been studied by using both cyclic voltammetry and differential pulse adsorptive voltammetry. A distinctive accumulation pattern was found for each of the stabilized enzymes at the static mercury drop electrode with respect to the native alanine aminotransferase. Adsorptive voltammetry was demonstrated to be a useful technique to assess the extent of chemical modification of this enzyme, which is indirectly related to their stability for use in biotechnological processes. The sue of differential pulse adsorptive voltammetry, after a preconcentration of the enzyme for 300 s at the electrode surface, has yielded a detection limit of 1.0 x 10(-9) M.

A procedure for the isolation of glutamate dehydrogenase (GDH) from human liver, which involves the use of ion-exchange chromatography on diethylaminoethyl cellulose and affinity chromatography on guanosine triphosphate conjugated to Sepharose 4B, is described. The adsorptive voltammetric behaviour of human GDH, bovine GDH and rabbit anti-human GDH antibody was optimised with respect to accumulation potential, accumulation time and scan rate. The lower limits of detection were 0.2 and 1.2 mg l-1 for human and bovine GDH, respectively, and the lower limit of detection for rabbit anti-GDH antibody was 0.04 mg l-1. The interaction of human GDH with rabbit anti-human GDH antibody was also examined using this method.

An alumina stationary phase has been assessed in the study of the retention behaviour of the anticancer drug cisplatin and its major hydrolysis products. Parameters such as buffer concentration in the mobile phase, pH, organic modifier and competing ion have been investigated in order to optimize chromatographic separation with ultraviolet detection. The separation scheme developed has been used to monitor the hydrolysis of cisplatin in aqueous and saline media, and to monitor the interaction of hydrolysed solutions of cisplatin with the amino acid cysteine. A new peak was observed in the chromatograms of such mixtures when they had been allowed to stand for periods of greater than 16 h and, from analysis of the data obtained, it was concluded that this new peak was due to a complex formed between the mono-aquo hydrolysis product of cisplatin and the amino acid.

The interaction of the anti-cancer drug cisplatin with human serum albumin and cystine has been investigated using differential pulse adsorptive voltammetry. Based on an understanding of the voltammetric behaviour of these biological molecules, which rely on the presence of the disulphide groups within their molecular structure for their electroactivity, it has been postulated that binding of cisplatin to these molecules occurs at the disulphide bond. A fractional coefficient for the binding of cisplatin to human serum albumin at pH 7.4 was calculated to be 0.32. The reactivity of hydrolysis products of cisplatin was shown to be greater than that of the parent drug.

The intensity transmitted by a device made up of a F.P. etalon that contains another internal tunable F.P. has been studied. The theoretical predictions about the wavelengths of the intensity transmission maxima of the device are derived as functions of the optical path length of the internal F.P. An experimental check of the theoretical predictions is also presented.

We have investigated the production of interleukin 2 (IL-2) by human T cells after their stimulation by phytohaemagglutinin (PHA). T cells isolated by rosetting with sheep erythrocytes produced high levels of IL-2. Further separation of rosette-forming cells, according to the expression of Fc receptors for IgG, showed that TG and non-TG cells are equally able to produce IL-2. The release of IL-2 by TG cells did not require DNA synthesis or functional Rc gamma receptors, since positively selected TH cells produced IL-2, even though they lacked lymphoproliferative responses to PHA and antibody-dependent cell-mediated cytotoxicity.

The techniques which have been employed for inversion of IR heterodyne measurements for remote sounding of stratospheric trace constituents usually rely on either geometric effects based on limb-scan observations (i.e., onion peel techniques) or spectral effects by using weighting functions corresponding to different frequencies of an IR spectral line. An experimental approach and inversion technique are discussed which optimize the retrieval of concentration profiles by combining the geometric and the spectral effects in an IR heterodyne receiver. The results of inversions of some synthetic ClO spectral lines corresponding to solar occultation limb scans of the stratosphere are presented, indicating considerable improvement in the accuracy of the retrieved profiles. The effects of noise on the accuracy of retrievals are discussed for realistic situations.

An evolutive study of the E.N.G. on 25 patients affected of chronic renal failure (c.r.f.) in their previous periods and during the dialysis programme was developed. At the same time a large study on various serum changes was carried on. It is observed that the motor conduction velocity (M.C.V.) shows a decreasing evolution during dialysis, which mathematical patters is a branch of an equilateral hyperbola, of equation: (see article) The Na and K evolutive curves are also significatively fitted to the same mathematical pattern. It is observed a direct and inverse lineal correlation between M.C.V. values and those ones of the Na and K respectively, with p less than 0,05 and p less than 0,01. It is not observed any correlation of significatively value with the other serum parameters studied (R.A., Cl, Urea, Total proteins, Hematocrit, Ca, P, Creatinine, fluids and acid-base equilibrium). After a renal transplantation the M.C.V. presents a growing trayectory of the same mathematical pattern described before, reaching normal values about a year post-transplantion. The levels of Sodium serum follow a parallel trayectory than that one of the M.C.V. The recovery of the remainders serum parameters after renal transplantion occour during the first week, except for the hematocrit. It only remains a parallelism between the evolutive changes of M.C.V./Natremia during dialysis stage and after renal transplantion. These results seem to show a close dependence between variation of M.C.V. and Natremia. The hipoxia role over the sodium pump and the consequent variations of Natremia are discussed.

Human lymphocytes are divided into two populations, thymus-dependent or T-cells, required for cell-mediated immunity, and B-cells which are thymus independent and responsible for antibody-mediated immunity. Conventional light microscopy cannot differentiate between T and B lymphocytes, but the introduction and studies of lymphocyte membrane markers have shown a lymphocyte heterogeneity. In the present paper, various methods for characterization of human peripheral blood lymphocyte cells; based on surface properties, have been studied. Because of the membrane markers of receptors on human lymphocytes, the immune function of the subpopulations may be described. Functional studies may be performed on cell suspensions in which subpopulations are eliminated or concentrated by means of their respective membrane markers. The surface of various lymphocyte subpopulations are characterized by the presence of receptors for immune molecules, immunoglobulin, complement, hormones active in immune processes, prostaglandins and histamine. The presence of these receptors may allow for the participation of the lymphocyte in the various stages of immune processes.

Theoretical determination of the instrumental function of a Fabry-Perot multipass interferometer as a function of the single pass instrumental function is studied. The polynomial dependences between the respective parameters characterizing the instrumental functions are given. An experimental check of the theoretical predictions is also presented.

In this paper we study the improvement in a laser Doppler velocimetry experiment when the Fourier transform of the time interval probability is measured instead of the intensity correlation function. The errors involved in determination of the velocity are found to be greatly improved for low scattered intensities.

Specific estradiol binding activities can be demonstrated in nuclear matrix preparations obtained from intact rat prostate nuclei. Some of the characteristics of these in vitro binding activities to intranuclear components are presented and compared to those exhibited by purified nuclear fractions. Examination of the effects of exposure to castration and testosterone on the number of nuclear matrix binding sites revealed that the quantity and quality (Type) of receptors was modified. Furthermore, these changes are prevented when protein synthesis was inhibited.

The concentration of meteoroids of mass ~ 10(-8) gram in interplanetary space, in the asteroid belt, and near Jupiter has been measured. The data confirm the Pioneer 10 observation that the asteroid belt is not highly populated with small meteoroids, suggest that the high concentration of small particles around Jupiter is the result of gravitational focusing, and provide an indication of the mass distribution of meteoroids in interplanetary space.

We relate our experiences about the number of exacerbations that certain food preservatives such as sorbic acid, benzoic acid, sodium benzoate, metabisulfite and sodium nitrate can provoke in 62 patients affected with ASA-triad in steroid dependent intrinsic asthma with nasal polyps and acute bronchospasm caused by aspirin ingestion, and in 80 patients with chronic urticaria (C.U.) as well as the first assays of the possible usefulness of the HRT (Histamine release test automatized using whole blood) for the etiologic diagnosis process. In the cases of ASA-triad, and after the ingestion of aspirin (alternating with lactose in identical capsule), we consider the result as positive when the reduction of FEV1 is superior to 20% from its baseline value. Regarding the cases of C.U., the symptoms always exacerbate twice as much with the same substance within 24 hours of its administration. We have performed the HRT on 59 patients (14 with ASA-triad, 11 with steroid dependent intrinsic asthma; 20 with C.U. were negative to oral intake of analgesics/additives and 14 with C.U. showed positive results). Successive dilutions were incubated for 30 minutes using: pyrazolones, acetylsalicylate of lysine, sodium salicylate, sodium benzoate and 4-hydroxybenzoic acid which did not produce liberation of histamine in 100 controlled individuals. All the determinations were done in duplicate, considering positive those superior to 20% of the difference between total and basal histamine. We have not observed any significant descent of the FEV1 with benzoate and salicylate in our group of 62 patients with ASA-triad, nor any manifestations presented with sodium metabisulfite, sodium nitrate and sorbic acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Folic acid was voltammetrically measured after preconcentration by adsorption at the static mercury drop electrode. Phase selective AC voltammetry provided the most sensitive stripping signal. After previous analyte extraction, using liquid-solid extraction with a C-18 reversed phase cartridge, the method was suitable for folic acid measurement in human serum. The detection limit was 5.9 x 10(-9) M with an overall precision of 9.9% (R.S.D.; n = 7) at the concentration level of 1.0 x 10(-7) M with a mean recovery of 57%.

Normal human T cells grown in continued cultures in medium containing conditioned medium (CM) from PHA-stimulated lymphocytes were studied for their ability to manifest three known forms of cell-mediated cytotoxicity: lectin-induced cellular cytotoxicity (LICC), natural killer cell (NK) activity, and antibody-dependent cellular cytotoxicity (ADCC). The cultured T cells (CTC) were very effective mediators of LICC, being cytotoxic even at very low attacker-target cell ratios in the presence of different lectins, and against different types of targets. When tested without the addition of lectin, the CTC demonstrated a low degree of spontaneous cytotoxicity. This spontaneous cytotoxicity might not be due to conventional NK cells however, since the CTC failed to show significant numbers of cells with Fc receptors (FcR) for IgG, and had no detectable ADCC activity. CTC could represent a population enriched in polyclonal activated T cells with low spontaneous cytotoxicity against a variety of allogeneic target cells, which is greatly enhanced by the addition of lectins dur ing the 51Cr release assay.

The particle flux measured by the meteoroid detectors on Pioneer 11 increased greatly while the spacecraft was near the rings of Saturn. The data suggest that the particles were associated with the rings and were not interplanetary meteoroids concentrated near the planet by gravitational focusing. The data also suggest that the E ring may be 1800 kilometers thick with an optical thickness greater than 10(-8).

Microscopic dissociation constants of 3-hydroxy-alpha-(methylamino)methyl-benzenemethanol have been calculated from the titration spectrophotomeric data (c = 3.8 x 10(-4) M. Ionic strength = 0.16; buffer system: H3BO3/KOH) by application of a spectral deconvolution method. The results found (pKa = 9.48; pKb = 9.71; pKc = 10.12 and pKd = 9.88) are in good concordance with those obtained from the conventional regression linear method (pKa = 9.45; pKb = 9.77; pKc = 10.14 and pKd = 9.81).

We have reported previously that insulin causes a complete but reversible desensitization to insulin action in rat hepatoma HTC cells in tissue culture, and that this insulin resistance is mediated by postbinding mechanisms rather than receptor down-regulation (Heaton, J. H., and Gelehrter, T. D. (1981) J. Biol. Chem. 256, 12257-12262). We report here that insulin causes a similar desensitization to the induction of tyrosine aminotransferase by the insulin-like growth factors IGF-I and IGF-II isolated from human plasma, and by multiplication-stimulating activity, the rat homologue of IGF-II. The results of both competition-binding studies and affinity cross-linking experiments indicate that insulin-like growth factors (IGFs) bind primarily to IGF receptors rather than to insulin receptors. The low concentrations at which these factors induce transaminase is consistent with their acting primarily via IGF receptors. This is confirmed by experiments utilizing anti-insulin receptor antibody which both inhibits 125I-insulin binding and shifts the concentration dependence of insulin induction of tyrosine aminotransferase to the right. This same immunoglobulin does not inhibit 125I-multiplication-stimulating activity binding and only minimally inhibits 125I-IGF-I binding. Anti-insulin receptor antibody also does not significantly shift the concentration dependence for the IGFs, suggesting that IGFs induce transaminase by acting via IGF receptors. Although insulin down regulates insulin receptors, it does not decrease IGF-I or IGF-II binding. We conclude that insulin causes desensitization of HTC cells to IGFs by affecting a postbinding step in IGF action, which may be common to the actions of both insulin and insulin-like growth factors.