A three-dimensional iterative scheme for an electromagnetic inductive applicator. An efficient iterative method for solving quasi-static electromagnetic field problems is presented. The electromagnetic field is generated by an inductive applicator and is represented as a superposition of two constituents, viz. a primary field in absence of the tissue configuration and a secondary field generated by the presence of the tissue. Then, for the secondary field a quasi-static approximation is employed. In the quasi-static field equations a relaxation function is introduced, such that the resulting equations can be solved iteratively. For a realistic three-dimensional model of a human hand numerical results are presented.


Reduced-order modeling for hyperthermia control. This paper analyzes the feasibility of using reduced-order modeling techniques in the design of multiple-input, multiple-output (MIMO) hyperthermia temperature controllers. State space thermal models are created based upon a finite difference expansion of the bioheat transfer equation model of a scanned focused ultrasound system (SFUS). These thermal state space models are reduced using the balanced realization technique, and an order reduction criterion is tabulated. Results show that a drastic reduction in model dimension can be achieved using the balanced realization. The reduced-order model is then used to design a reduced-order optimal servomechanism controller for a two-scan input, two thermocouple output tissue model. In addition, a full-order optimal servomechanism controller is designed for comparison and validation purposes. These two controllers are applied to a variety of perturbed tissue thermal models to test the robust nature of the reduced-order controller. A comparison of the two controllers validates the use of open-loop balanced reduced-order models in the design of MIMO hyperthermia controllers.


Ambulatory oxygen uptake measurement system. An apparatus for monitoring prolonged measurement of oxygen uptake without discomfort has been developed. The system is based on the open flow-through principle. The subject wears a hood through which air is drawn by an exhaust blower. Oxygen concentration is kept constant by a servo-controlled blower, so that flow rate is essentially proportional to oxygen uptake. The flow rate of the main stream is measured by a time-of-flight flowmeter located in the exhaust hose. Oxygen concentration is measured by a limiting-current oxygen sensor. The signals representing flow rate and oxygen concentration are digitized and stored in a memory. All of the equipment is assembled in a small package (wt = 3 kg) which the subject carries on his back. The memory chip is removed from the portable device after each experiment. Data are transferred from the memory to a microcomputer and then an oxygen uptake trend is estimated. Response of the system to a step input is about 30 s. Compared with a commercially available oxygen monitoring system (Magna 88, P. K. Morgan Ltd., Rainham, UK), the maximum difference was 0.15 L/min within an oxygen uptake range of 0.25-2.3 L/min. Thus, the measurements made with our portable device agree with the results obtained using the conventional method.


A microfluorometer for measuring diffusion of fluorophores across the cornea. A microscope has been modified to a confocal spatially scanning fluorometer so that the concentration profile of a fluorophore across an isolated cornea can be measured. A slit of light is focused through one half of the objective to excite fluorescence. A confocal slit is placed at the image-plane of the microscope to collect the fluorescent light from the tissue which passes through the other half of the objective. The fluorescent light falls on to the cathode of a photomultiplier whose output is amplified by a lock-in amplifier. Scanning across the cornea is achieved by a stepper motor coupled to the fine focus of the microscope. The performance of the instrument has been assessed by studying the transport of fluorescein, carboxyfluorescein, and rhodamine B through intact rabbit corneas. A depth resolution of about 10 microns has been achieved with a 40x objective. This resolution is sufficient to determine concentration gradients in the epithelium as well as the stroma and to partially resolve the endothelium. The potential errors in the technique, resulting from limited resolution, light scattering and absorption, quenching of fluorescence, and binding of the fluorophores, are discussed.


A three-dimensional architecture for a parallel processing photosensing array. A three-dimensional architecture for a photosensing array has been developed. This silicon based architecture consists of a 10 x 10 array of photosensors with 80 microns diameter, through chip interconnects to the back side of a 500 microns thick silicon wafer. Each photosensor consists of a 300 x 300 microns pn-junction photodiode. The following processes were used to create this photosensing architecture: 1) thermomigration of aluminum pads through an n-type silicon wafer; 2) creation of pn-junction photosensors on one side of the wafer; and 3) creation of aluminum pad ohmic contacts to the thermomigrated, through chip interconnects and the substrate on the back side of the wafer. The electrical and optical characteristics of the three-dimensional architecture indicates that it should be well suited as a photosensing framework around which a "silicon retina" could be built.


Electric and dielectric properties of wet human cortical bone as a function of frequency. In this paper, the electrical and dielectric properties of wet human cortical bone from a distal tibia were examined as a function of frequency and direction. The resistance and capacitance of the cortical bone specimens were measured at near 100% relative humidity. The measurements were made in all three orthogonal directions at discrete frequencies ranging from 120 Hz to 10 MHz using an LCR meter. At a frequency of 100 kHz, the mean resistivity and specific capacitance for the ten cortical bone specimens were 1.55 k omega-cm and 33.81 pF/cm in the axial direction, 15.79 k omega-cm and 9.98 pF/cm in the circumferential direction, and 21.5 k omega-cm and 9.83 pF/cm in the radial direction. All electrical and dielectric properties except the resistivity and the specific impedance were highly frequency dependent for the frequency range tested. However, the resistivity and specific impedance were relatively less frequency dependent. All electrical and dielectric properties were also transversely isotropic in nature, the values for the axial direction being different from the values obtained for the two transverse directions.


Feature-based detection of the K-complex wave in the human electroencephalogram using neural networks. The main difficulties in reliable automated detection of the K-complex wave in EEG are its close similarity to other waves and the lack of specific characterization criteria. We present a feature-based detection approach using neural networks that provides good agreement with visual K-complex recognition: a sensitivity of 90% is obtained with about 8% false positives. The respective contribution of the features and that of the neural network is demonstrated by comparing the results to those obtained with i) raw EEG data presented to neural networks, and ii) features presented to Fisher's linear discriminant.


Impedance bacteriometry: medium and interface contributions during bacterial growth. We measured impedance in a cell containing culture broth inoculated with E. coli, before and during bacterial growth. The electrode interface impedance components (Ri, Xi) and the culture medium component Rm were separated by making use of the Warburg's model frequency dependent properties. Measurements were carried out at different frequencies (from 18 Hz to 18 kHz) with a constant current impedance bridge as growth proceeded. It was found that: Growth curves for Ri and Xi showed a similar temporal pattern within the frequency range of 18-100 Hz. Dispersion was not observed in Rm, meaning that the same growth response was obtained within the 18-18,000 Hz range. At low frequency, the resistive and capacitive reactive components, or Rb and Xb, respectively, were directly measured, where Rb = (2.Ri + Rm) and Xb = 2.Xi and, at high frequency (above 5 kHz), Rm was obtained (for Zi is negligible). Thus, Ri was easily discriminated from Rm by simple arithmetic: Ri = [Rb (low f) - Rb (high f)]/2. In four experiments, the maximum spread of Xi, Ri, and Rm was smaller than 5%, indicating good repeatability. There is potential new information in dissecting out the growth curve in three separate component curves.


Evaluation of three template matching algorithms for registering images of the eye. The purpose of this paper is to evaluate the ability of three similarity measures to register a template in a sequence of near-infrared eye images. Three measures are evaluated: the normalized correlation coefficient (rho), the sum of absolute valued differences (SAVD), and a relatively new technique based on a sign change criterion, called the stochastic sign change criterion (SSC). Performance is measured in terms of the method's ability to track the pupil center derived from fitting a general 2-D ellipse to the pupil contour. Experiments using static eye images indicate that rho is not a reliable similarity measure. Conversely, both SAVD and SSC show enough potential to merit an investigation into their performance in tracking dynamic eye movements. It is anticipated that SAVD and SSC can accommodate a range of eye movements spanning at least 60 degrees horizontally and 40 degrees vertically.


Correlation dimension of optokinetic nystagmus as evidence of chaos in the oculomotor system. The correlation dimension of optokinetic nystagmus (OKN) eye movements from a normal human subject was computed. Results indicate a value of about 2.8, indicating the possibility of chaotic dynamics in OKN. This was found to differ from the dimension of an artificial OKN signal with the same second-order statistics.


Proliferation of Nb2 lymphoma cells in vitro in response to interleukin-7. An attempt was made to investigate the proliferative effect of interleukin-7 (IL-7) on a rat Nb2 T-cell lymphoma line. It was demonstrated that both human and mouse IL-7 stimulated these cells to proliferate in a dose dependent fashion in culture medium containing 10% horse serum. The maximum activities of mIL-7 and hIL-7 were observed at 100 and 1000 units/ml with their half-maximal response of 10 and 50 units/ml, respectively. In a totally serum-free culture condition, mIL-7 produced a similar cellular proliferation, whereas hIL-7 was much less effective. The effectiveness of IL-7 on Nb2 cells was completely abolished by antibody to IL-7, but not by antibody to IL-2. Therefore, Nb2 cells may serve as a simple, convenient and sensitive assay for monitoring the biological activity of IL-7 in vitro. In addition, these cells are also useful for studying the lymphopoiesis of T-cell lineage regulated by IL-7.


Increased production of interleukin-1 and tumor necrosis factor by human monocytes treated in vitro with cisplatin or other biological response modifiers. Supernatants collected from cisplatin, lipopolysaccharide (LPS), muramyl dipeptide (MDP) or interferon-gamma (IFN-gamma) treated human monocytes enhance the thymocyte proliferation by a submitogenic concentration of concanavalin A. Also supernatants collected from cisplatin or IFN-gamma treated monocytes demonstrated enhanced cytotoxicity against actinomycin-D treated L 929 cells, suggesting that cisplatin or rIFN-gamma treated monocytes release tumor necrosis factor (TNF) into the culture medium. The supernatant collected from untreated monocytes showed only little IL-1 and TNF activity.


Detection of interleukin 2 receptors on murine lymphocytes using fluorescent interleukin 2. Murine interleukin 2 receptors found on freshly isolated and on in vitro activated lymphocytes were identified using a fluorescent interleukin 2 (IL2F). Three percent of freshly isolated small thymocytes bound the IL2F; these cells appeared to be dual CD4 and CD8 positive cells. Ten percent of the larger thymocytes also bound the IL2F; phenotypically, these cells were more heterogenous in their CD4/CD8 composition than the small IL2F+ thymocytes. Freshly isolated splenocytes bound more IL2F than did the thymocytes. Twenty-four percent of the small splenocytes were IL2F+ and they were mostly B220+ cells. Half of the larger splenocytes were IL2 receptor positive and these cells consisted of B and T cells. Using mitogen stimulated splenocytes, three times as many LPS stimulated B220+ blasts bound the fluorescent IL2 than freshly isolated large B220+ cells; this level of IL2F binding was maintained for four days. Of the Con A blasts, more CD8+ cells (30%) bound IL2F than did CD4+ blasts (19%); these cells maintained this level of IL2F binding for only three days. The IL2F binding could be completely inhibited by excess unlabeled IL2 and could be inhibited by 92% using a monoclonal antibody directed against the IL2 binding region of the IL2 alpha receptor, indicating that IL2F can bind to both IL2 alpha and IL2 beta receptors.


Probing molecular changes induced in DNA by reactive oxygen species with monoclonal antibodies. Antibodies reactive with native double stranded DNA are characteristic of the chronic inflammatory disease systemic lupus erythematosus. Native DNA is however, a poor immunogen and the mechanism of anti-DNA antibody production is incompletely understood. Modification of DNA can increase its immunogenicity and in inflammatory disease states reactive oxygen species produced from phagocytic cells have been shown to thus modify DNA. In this study, monoclonal antibodies produced spontaneously by two mice strains with lupus-like disease were used in a competition ELISA to monitor changes to DNA induced by reactive oxygen species. Different procedures for reactive oxygen species generation were found to cause distinct and characteristic changes to DNA involving modifications of base residues, the sugar-phosphate backbone and the gross conformational structure of double-stranded DNA. In view of this, it may be possible to use these antibodies further to probe DNA and infer the source and nature of the reactive oxygen species it has been exposed to, particularly in vivo.


Soluble interleukin-2 receptors in recurrent miscarriage and the effect of leukocyte immunotherapy. The relationship between soluble interleukin-2 receptors (IL-2R) and pregnancy outcome was investigated in women with a history of miscarriage, some of whom were treated with partner-specific leukocyte immunotherapy. IL-2R were significantly elevated in patients with a poor obstetric history possessing cardiolipin antibodies, and higher levels were also found in recurrent aborters without cardiolipin antibodies who had particularly bad histories. Furthermore, values obtained during early pregnancy were lower in patients who subsequently had successful pregnancies than in those who aborted again. Eight out of 35 patients immunised with their partners' lymphocytes, but none of 16 patients immunised with their own cells, showed a marked decrease in IL-2R levels a month later. It is possible that the minority who respond to immunotherapy with a marked drop in IL-2R may be the same minority who may derive benefit from this treatment.


Rapid quality evaluation of hybridomas using ELISPOT and cell-ELISA techniques. We have used the ELISPOT assay in combination with ELISA procedures for rapid evaluation of properties of three different murine hybridoma cell lines, 104-I, -B and -G, secreting IgG1 kappa monoclonal antibodies against a 104-mer synthetic peptide from the C-terminal part of HIV-1 p24. By conventional ELISA we obtained data suggesting that the three monoclonal antibodies had different affinities. By cell-ELISA we found that the IgG1 kappa secretion rate varied between cells (4,000 to 14,000 antibody molecules/cell/min), and ELISPOT showed that only 4-5% of 104-I cells gave antigen-specific spots, indicating a cell population with diverse properties. We recommend that the ELISPOT and cell-ELISA techniques should be used routinely to supplement conventional ELISA procedures for rapid evaluation of hybridoma properties.


Low number of antibody producing cells in patients with sickle cell anemia. B cell function is impaired in patients with sickle cell anemia. Although the number of surface IgM positive cells was similar in sickle cell patients and controls, in vitro spontaneous IgM, and PWM stimulated IgA, IgM, and IgG synthesis was significantly lower in the patients than in controls. The number of PWM induced and antigen specific immunoglobulin producing cells after immunization with Pneumovax, containing 21 serotypes of Streptococcus pneumoniae, was about 100-fold lower in the patients as compared with controls. Finally, the ability of the patients' peripheral blood mononuclear cells to proliferate in response to mitogens (PWM, SAC, PHA) was diminished. Because of the observed impairments in both nonspecific and antigen specific immunoglobulin synthesis and cell proliferation assays in the patients, we determined serum concentrations of IL-4 and IL-6, two cytokines associated with antibody production. IL-4 concentrations appeared low in sickle cell patients, and correlated with that of serum IgM. We hypothesize that B cell maturation in sickle cell patients is arrested at an IL-4 dependent stage.


Analyses of the primary in vitro responsiveness of non-immune porcine peripheral blood mononuclear cells with reference to immunization by African swine fever virus antigen and treatment with leucine methyl ester. Peripheral blood mononuclear cells (PBMC) from non-immune pigs were immunized in vitro using African swine fever (ASF) virus antigen with concomitant mitogenic stimulations known to have varying effects on B and T lymphocyte activity. None of these conditions, including those previously reported as being successful for the in vitro immunization of non-immune porcine PBMC with ASF virus antigen, supported the induction of specific antibody. Due to the reports on in vitro immunization of human PBMC, attempts were made to control suppressor cell activity in the porcine PBMC from non-immune pigs through L-leucine methyl ester (Leu-OMe) treatment. Upon immunization of the Leu-OMe treated PBMC with ASF virus antigen, concomitant with mitogen or cytokine stimulations, no specific antibody production was detected. Nevertheless, aspecific porcine immunoglobulin secretion was observed. Further analysis of the PBMC responsiveness demonstrated that 2.5 mM Leu-OMe (the dose recommended for use with human PBMC) suppressed mitogen-induced porcine lymphocyte proliferation, but in the absence of any detectable cytotoxicity. In fact, both anti-ASF virus antigen specific immunization and stimulation with "T-lymphocyte" mitogens were suppressed, whereas pokeweed mitogen stimulation of B lymphocyte aspecific immunoglobulin secretion was unaffected. Consequently, it was not possible to immunize in vitro non-immune porcine PBMC with ASF virus antigen as had been previously reported, nor was it possible to transfer the technology successfully used with non-immune human PBMC to the in vitro stimulation/immunization of non-immune porcine PBMC. The furtherance of this work will require greater insight into the immunobiological parameters and dynamics of the stimulation of non-immune porcine peripheral blood leukocytes, which are not as simple as previously reported, nor the same as identified with human PBMC.


Rapid immunoassays for the measurement of immunoglobulin G subclass concentration in immunoglobulin preparations and human serum. Enzyme immunoassays (EIA) capable of determining total IgG1, IgG2, IgG3 and IgG4 subclass concentrations in human serum preparations have been developed. Subclass-specific monoclonal antibodies (mAbs) are bound to polyacrylamide bead-conjugated anti-mouse immunoglobulin antibodies. Bound immunoglobulins are detected with a peroxidase-conjugated anti-IgG antibody or a biotin-conjugated anti-IgG antibody followed by peroxidase streptavidin. The standard curves were found to be linear in the regions 16.0-2.0 micrograms/ml for IgG1, 4.0-0.5 micrograms/ml for IgG2, 0.4-0.06 micrograms/ml for IgG3 and 0.25-0.05 micrograms/ml for IgG4. Coefficient of variation (CV) values range from 0.32-7.32% for IgG1, 0.66-4.85% for IgG2, 1.62-6.85% for IgG3 and 0.05-6.47% for IgG4 standard curves. The inter-assay variability for the control human serum samples was 9.6% for IgG1, 6.7% for IgG2, 9.5% for IgG3 and 6.8% for IgG4.


Locally superantigen-activated peritoneal cytolytic T lymphocytes belong to the CD8+ CD45RC- subset and lyse MHC class II+ tumor cells. Bacterial encoded superantigens (SA) are capable of activating and targeting cytolytic human and mouse T lymphocytes (CTL) to lyse major histocompatibility complex class II positive (MHC class II+) target cells. In this study both in vitro and in vivo activated rat CTL were directed against MHC II+ tumor targets by bacterial encoded SA. Polyclonal in vitro activation of rat peripheral blood T lymphocytes generated CTL capable of killing MHC class II+ human BSM cells coated by staphylococcal enterotoxin (SE) -A, -E, -D, and TSST-1 but not by SEB or SEC1-3. Allo selective peritoneal CTL generated by intraperitoneal stimulation with allogeneic spleen cells were directed against BSM cells by SEA, -D, and -E but not by SEB, SEC1-3 or TSST-1. Based on the above observations, and in order to locally activate CTL, SEA was chosen for in vivo priming of rats by intraperitoneal inoculation of the toxin. SEA injection generated highly cytolytic CTL, and maximum cytolytic responses were seen at 50-250 micrograms SEA per animal with a peak in response 48-72 hours after injection of the toxin. The cytolytic activity of peritoneal SEA reactive effector cells was confined to the TCR alpha beta+ CD4- CD8+ CD45RC- cell population. MHC class II- colon carcinoma cells were insensitive to lysis by SEA reactive CTL but colon carcinoma cells induced to express MHC class II by interferon-gamma (IFN-gamma) treatment were efficiently lysed in the presence of SEA. Comparison of rat and human MHC II+ colon carcinomas revealed a peak in sensitivity to lysis at 10-100 ng SEA/ml for both tumor targets. These findings suggest that superantigens can be used in local immunotherapy of peritoneal tumors such as ovarian and colorectal carcinomatosis, with inducible or constitutive expression of MHC class II.


In vitro antigen-specific IgE response is refractory to suppression by interferon-gamma. Although interferon (IFN)-gamma has been shown to be involved in the down-regulation of polyclonal IgE response in murine B cells that were activated by lipopolysaccharide (LPS) and interleukin 4 (IL4), effects of IFN-gamma on antigen-specific IgE responses have not been fully investigated. We have developed the following culture systems for inducing antigen-specific IgE responses in murine lymphocytes, and examined the effects of IFN-gamma on the following responses in vitro. (1) Anti-trinitrophenyl (TNP) IgE response induced by the stimulation with TNP-keyhole limpet hemocyanin (KLH) of BALB/c spleen cells that had been primed in vivo with the same antigen. (2) Anti-TNP IgE response induced by the coculture of unprimed C3H B cells with conalbumin (CA)-specific helper T cell clone, D10.G4.1, in the presence of TNP-CA. The former anti-TNP IgE response was not suppressed, and the latter suppressed only partially (less than 30%) by the addition of 100-200 U/ml IFN-gamma. In contrast, polyclonal IgE response in murine B cells that were stimulated by LPS and IL4 was abolished by 10 U/ml IFN-gamma. These results indicate that IgE production from antigen-stimulated B cells, in contrast to those activated polyclonally, are refractory to direct suppression by IFN-gamma.


Selective enhancement of interleukin 1 beta production in myelomonocytic cell lines by insulin and its related cytokines. The production of interleukin 1 (IL-1) by lipopolysaccharide (LPS)-stimulated myelomonocytic cell lines ML-1, THP-1 and PL-21 was significantly enhanced by the addition of insulin, insulin-like growth factor (IGF)-I or IGF-II into the cell cultures. The IL-1 activity in the supernatants from cell cultures stimulated with LPS and insulin was completely neutralized by anti-IL-1 beta antibody. Anti-IL-1 alpha antibody had no inhibitory effect. Insulin itself did not stimulate IL-1 beta production directly, but increased it in the mitogen activated cells. However, insulin had no enhancing effect on the production of IL-1 alpha by human T cell lymphotropic virus-I (HTLV-I)-infected T cell lines or on IL-2 production by mitogen-stimulated leukemia T cell lines. Thus, insulin and its related cytokines are shown here as other molecules selectively modulating the production of IL-1 beta in myelomonocytic cell lines.


Augmentation of monocyte-mediated cytocidal activity by a low dose tumour necrosis factor measured by the kinetic colorimetric microplate assay. This paper describes a simple kinetic colorimetric assay for the quantitation of human peripheral blood monocyte-mediated cytotoxic activity against tumour cells. Isolated effector monocytes were cultured overnight with an increasing number of target cells in 96-well microplates. Cytotoxic activity of monocytes was determined by modified nitroblue tetrazolium (MTT) dye assay using standard ELISA reader offering possible automation. The test was performed with three different effector/target cell ratios using a fixed number of monocytes. This allowed the expression of cytotoxic activity of monocytes in cytotoxic activity units. The assay was found to be a simple method to demonstrate that low doses of TNF (1 U/ml) enhanced monocyte-mediated cytotoxicity.


Brief treatment with rapamycin in vivo increases responsiveness to alloantigens measured by the mixed lymphocyte response. Rapamycin (RPM) is a macrolide fermentation product that prolongs rodent allograft survival more potently and effectively than cyclosporin A (CsA) and FK506. Experiments in vitro have shown that RPM inhibits lymphoproliferation by mechanisms of action that are different from other immunosuppressants. Much less is known, however, about the effects of RPM on immune cells in vivo compared to other immunosuppressive drugs. Others have shown that in vivo treatment with CsA suppresses the responsiveness of cells in the mixed lymphocyte response (MLR). Therefore, to investigate the effects of RPM in vivo, rats were treated with RPM and their lymphoid cells used as responder cells in the MLR. We confirmed that the proliferation of cells in the MLR was decreased after treatment with CsA in vivo. In contrast, treatment with RPM in vivo greatly increased the proliferative response to alloantigen in the MLR. These findings show that the effects of RPM and CsA on immune cells in vivo differ. Perhaps the cells proliferating in the MLR after in vivo RPM treatment play a role in the regulation of the immune system that enables this immunosuppressant to prolong allograft survival so effectively in rodents.


Mechanism of enhanced phagocytic response in protein a treated rat macrophages. Protein A of S. aureus Cowan I has been shown to stimulate macrophage mediated phagocytosis. The present study was undertaken to understand the mechanism involved in the enhancement of phagocytosis of peritoneal macrophages by protein A. The lucigenin and luminol-dependent chemiluminescence (CL) of rat peritoneal macrophages, after incubation with various concentrations of protein A, flow-cytometric studies using DCFH-DA as a fluorescent compound and phagocytosis of sheep red blood cells (SRBCs) by rat peritoneal macrophages were studied. A significant increase in lucigenin dependent CL due to formation of superoxide anions (O2-.) and in luminol dependent CL due to formation of hydrogen peroxide (H2O2) was observed in protein A treated macrophages. A significant increase in intracellular hydrogen peroxide (H2O2) was also observed along with an increase in phagocytosis of SRBCs by protein A treated macrophages. The present findings indicate that protein A helps to increase phagocytosis and triggers respiratory burst of macrophages. Thus, both increased phagocytic response and respiratory burst of macrophages in protein A treated animals may be contributing to the antitumor property of protein A reported earlier.


Suppression of interleukin 4 production from type 2 helper T cell clone by antisense oligodeoxynucleotide. Type 2 helper T cell (Th2) clone has been reported to secrete interleukin (IL) 4 and IL5 in response to the specific antigen presented by syngeneic antigen-presenting cells. In the present report, we synthesized phosphorothioate analogue of an antisense oligodeoxynucleotide complementary to nucleotide 17-36 of IL4 mRNA (S-oligo), and tested its ability to inhibit IL4 production from a Th2 clone, D10.G4.1. (D10). D10 cells were cultured with mitomycin C-treated C3H spleen cells in the presence of 100 micrograms/ml conalbumin for 48-72 h. Secreted IL4 and IL5 were assayed biologically using HT2 cells and dextran sulfate-stimulated murine B cells, respectively. When 5-10 micrograms/ml S-oligo was added to the culture, IL4 production from D10 was suppressed by 70-90%. The same concentrations of S-oligo inhibited neither the antigen-induced proliferation of D10 nor the secretion of IL5 from the Th2 clone. These results suggest that this S-oligo is useful for inhibiting the production of IL4 preferentially without affecting other functions of Th2 cells.


Pneumocystis carinii induction of tumor necrosis factor-alpha by alveolar macrophages: modulation by pentamidine isethionate. Pneumocystis carinii, and the inflammatory response it provokes, together contribute to irreversible lung damage in immunocompromised patients. P. carinii cysts were found to be capable of inducing tumor necrosis factor-alpha (TNF) release from alveolar macrophages in a concentration-dependent manner. At physiologically achievable concentrations, pentamidine isethionate (pentamidine) substantially reduces such production. Pretreatment of alveolar macrophages (AM phi) with interferon-gamma (IFN-gamma) synergizes with P. carinii to produce increased levels of TNF, a condition which pentamidine was also able to antagonize. Pentamidine treatment did not interfere with the phagocytic ability of AM phi. Considering clinical reduction of TNF could lessen P. carinii pneumonia (PCP) induced inflammation, the efficacy of pentamidine in the treatment of PCP may be partially associated with its ability to inhibit the release of inflammatory mediators such as TNF.


"NK-like" T cytotoxicity against B lymphocytes in a hypogammaglobulinemic patient. Physiologically, cells with NK activity appear to exert a negative control on immunoglobulin production. The clinical association of large granular lymphocyte (LGL) proliferation with hypogammaglobulinemia suggests that these functional NK cells could also be involved in pathological situations. We studied in vitro lymphocyte functions in a patient presenting LGL proliferation associated with hypogammaglobulinemia. The CD3+ CD8+ CD57+ CD16- phenotype lymphocytes expressed a high NK type cytotoxicity towards K562 targets, suggesting that they may be considered as "NK-like" T cells. We cultured the patient peripheral blood mononuclear cells (PBMC) with control subject PBMC and with PBMC from two other subjects with B chronic lymphocytic leukemia (B-CLL) of the CD20+ CD21- CD10- phenotype. Patient PBMC exhibited a lytic activity on control PBMC and on the B lymphocytes of one of the two B- CLL but only in the presence of PWM. This activity was not exerted by the culture supernatant and required a cell-to-cell contact. We suggest that the hypogammaglobulinemia observed in this patient may be related to a cytotoxic effect exerted on B lymphocytes by a CD3+ CD8+ CD57+ CD16- LGL proliferation.


The effect of BCG on thoracic duct lymphocytes. Adoptive immunotherapy is becoming increasingly more important in the management of advanced malignancies. This report describes the results of immunomodulation therapy with BCG in the Dunning tumor. In addition it describes new techniques in the harvesting of lymphocytes. Thoracic duct lymphocytes from 34 rats were evaluated for the effect of the presence of the Dunning R-3327 AT-3 tumor as well as for the response to bacillus Calmette Guerin (BCG). Both tumor and BCG resulted in significant changes in the helper/suppressor T cell ratios.


Humoral immune response to the antigen administered as an immune complex. Antigen (HSA) bound in immune complexes at equivalence with syngeneic anti-HSA antibodies elicit much stronger humoral immune response then soluble HSA. On the other hand, administration of immune complexes formed with xenogeneic (rabbit) anti-HSA antibodies suppressed humoral immune response against HSA, but not against rabbit IgG in mice. We suggest that immunization with antigen bound in immune complex might represent a powerful tool in enhancing humoral immune responses.


Complement-dependent cytotoxicity for negative selection at the mRNA level. Complement-Dependent Cytotoxicity (CDC) is a common technique used for isolating and characterizing cell populations. However, the molecular events resulting from CDC-mediated cell injury remain obscure. In order to use CDC as a selection procedure for studies at the RNA level, we examined if CDC is associated with rapid degradation of RNAs from target cells without affecting the stability and viability of RNAs of non-target cells. Using a model of anti-CD3-mediated CDC, we show that T cell-specific RNAs were absent immediately after CDC. However, ribosomal RNAs and mRNAs from non-targeted cells (non-T cells) were not affected by CDC. Our results indicate that CDC is associated with rapid degradation of only target cell RNAs, validating CDC as a method for cell isolation without interfering with further studies at the RNA level.


Polymorphism of age-related changes in the antibody response to the hapten phosphorylcholine. Aging is accompanied by changes in the immune system that occur at different levels and at different periods of time. We have studied age-related changes in isotype and idiotype of the antibody response to hapten phosphorylcholine (PC) in C57BL/6, and A mice and in the congenic MRL/Mp(-)+/+ and MRL/Mp-1pr/1pr strains. Three groups, representing young, middle and old age were immunized with PC-keyhole limpet hemocyanin. Total anti-PC antibody and the contribution of each isotype and of the T15 idiotype were assessed in the initial and late response. Some features of the antibody-response were similar in all the strains tested, e.g. the largest quantity of anti-PC antibody is formed in middle age and IgM is dominant in the initial response. However, remarkable differences occur in the isotype and idiotype predominance. Particularly, congenic MRL/Mp strains, prone to autoimmune disease, express the T15 idiotype only at low levels, even though IgM, which normally expresses this idiotype, is produced in large amounts. Furthermore, the late (memory) response of the MRL/Mp strains is dominated by IgG2b rather than IgG1, which is the predominant isotype in mice of long-lived strains. We conclude from these results that the number of T helper cells, involved in isotype regulation decreases with age and that there is a genetic variation, i.e., polymorphism in the ability to express T15-idiotype producing subtypes.


The effect of hydrophilicity-hydrophobicity and solubility on the immunogenicity of some natural and synthetic polymers. The general effects of solubility and hydrophobicity-hydrophilicity on the immunogenicity of synthetic and natural polymers are presented. The degree of hydrophobicity or hydrophilicity was determined from contact angle measurements. The surface tension components, obtained from the contact angles, were then correlated with the degree of immunogenicity for each substance. The results indicate that highly hydrophobic and highly hydrophilic polymers are not immunogenic. Moderate hydrophobicity as well as moderate hydrophilicity, and solubility in water favor immunogenicity (provided the molecular mass be at least 10,000 Da). For example, the solubilization of zein (a hydrophobic insoluble maize protein) prior to immunization causes zein to become immunogenic.


Pokeweed mitogen induces p55 interleukin-2 receptor expression on human monocytes and its effect on interleukin-2 activated monocyte cytotoxicity. Activation of human peripheral blood monocytes by pokeweed mitogen (PWM) results in the expression of interleukin 2 receptor(IL-2R) p55 chains, which are absent on resting monocytes. By dual-fluorescence flow cytometry, we found PWM induced detectable numbers of IL-2R+ cell which were further identified as LeuM3+ monocytes (22.91% of the LeuM3+ cells were IL-2R+ within 24h, and 32.17% in 48h). In addition, LPS can also induce IL-2R on 15.39% of LeuM3+ cells. On the contrary, other mitogens such as PHA or Con A, and cytokines as IFN-gamma, IL-2, M-CSF, TNF-alpha and IL-1 beta showed no influence on the IL-2R expression on monocytes. It was also noticed that PWM itself had no direct effect on HLA-DR antigen expression on LeuM3+ cells. The addition of IL-2 to PWM-pretreated IL-2R positive monocytes significantly augmented their tumoricidal activity. Thus monocytes when activated underwent a series of phenotypic and functional changes including the expression of IL-2R which may provide an important immunoregulatory pathway.


Specificity analysis of antibodies formed in rabbits to a mannosyl trisaccharide: similarity with lectin binding activity. Para-aminophenyl O-alpha-D-mannopyranosyl-(1-->2)-alpha-D-mannopyranosyl- (1-->6)-alpha-D-mannopyranoside linked to bovine serum albumin as an antigen. The para-aminophenyl derivative of Man alpha 1-->2Man alpha 1-->6Man alpha 1-->was coupled via a diazotization reaction to bovine serum albumin, and the resulting glycoconjugate was used to immunize two rabbits. The resultant antisera were tested for reactivity with a number of related mono, di- and trisaccharides to determine the immunodominant portion of this trisaccharide. Two populations of antibody resulted, one of which required the reducing end mannose, and could react with either an N-acetylglucosamine or a mannose as the penultimate sugar. The other population reacted with the Man alpha 1-->2Man alpha 1-->6Man alpha 1-->. The aglycone moiety and its configurations play an important role in determining the specificity of antibodies to this synthetic antigen. The similarity of this reactivity to the reactivity of mannose binding lectins is discussed.


trans,trans-Muconic acid, a reliable biological indicator for the detection of individual benzene exposure down to the ppm level. trans,trans-Muconic acid (2,4-hexadienedioic acid) (t,t-MA) is a minor benzene metabolite which can be used as a biological indicator for benzene exposure. The purpose of the study was to evaluate the limits of use of t,t-MA for detection and quantification of occupational exposures to benzene, particularly on an individual scale, phenol being used as the metabolite of reference. A simple and sensitive method previously described by the authors was carried out to analyse t,t-MA in 105 end-of-shift urinary samples from 23 workers exposed to benzene used as an extraction solvent for "concretes" recovery in the perfume industry. Good correlations were found between atmospheric benzene and both metabolites (uncorrected or corrected for creatinine) or between the metabolites themselves, with correlation coefficients from 0.81 to 0.91 (P < 0.0001). Correlation- coefficients were not improved after correction for creatinine. The overall individual benzene exposure range, median, and arithmetic mean were respectively 0.1-75, 4.5, and 9.0 ppm with corresponding t,t-MA excretion of 0.1-47.9, 5.2 and 8.9 mg/l (uncorrected) and phenol excretion of 1.4-298, 30.9, and 42.2 mg/l (uncorrected). In the control group (145 determinations for t,t-MA and 76 for phenol from 79 individuals) the range, median, and arithmetic mean were respectively < 0.04-0.66, 0.08, and 0.13 mg/l (uncorrected t,t-MA) and 1.5-42.0, 9.85 and 11.3 mg/l (uncorrected phenol). t,t-MA was far more specific than phenol and could be easily and practically used to estimate with a given probability the upper or lower corresponding benzene concentrations down to around the ppm level.(ABSTRACT TRUNCATED AT 250 WORDS)


A cross-sectional study on the brainstem auditory evoked potential among workers exposed to carbon disulfide. In order to clarify the chronic effect of carbon disulfide (CS2) on the central nervous system (CNS), the brainstem auditory evoked potential (BAEP) was measured in spinning workers exposed to CS2 in a viscose rayon manufacturing factory and unexposed workers in Japan. Workers exposed to CS2 were divided into three groups according to length of exposure: current spinning workers with an exposure duration of more than 240 months (L group, n = 34), current spinning workers with an exposure duration of 24-84 months (S group, n = 25), and former spinning workers with an exposure duration of more than 120 months (R group, n = 16). Unexposed controls were selected from workers in a nylon filament factory using the same criteria (N group; n = 40). BAEP records were analyzed based on the latencies of three main components (I, III, V) and interpeak latencies (I-III IPL, III-V IPL, I-V IPL). Latencies of component V, III-V IPL, and I-V IPL in the L group were significantly greater (P < 0.01, P < 0.05, P < 0.05, respectively). The significantly, higher III-V IPL in the L group suggested that in humans, chronic exposure to CS2 involves the auditory ascending tract in the brainstem. Recovery from this neurotoxic effect is apparently possible, as the BAEP parameters in the R group were not significantly higher than those of the N group despite the long previous CS2 exposure of the R group.


Urinary excretion of 3,4-dimethylhippuric acid in workers exposed to 1,2,4-trimethylbenzene. The urinary excretion of 3,4-dimethylhippuric acid (34DMHA), a 1,2,4-trimethylbenzene (124TMB) metabolite, was investigated in workers exposed to 124TMB vapor. The time-weighted average of exposure to 124TMB was determined with a diffusive sampler. For biological monitoring of exposure, urine samples were collected from individual workers and analyzed for metabolites by high-pressure liquid chromatography. The concentration of urinary 34DMHA had a positive correlation with the level of exposure to 124TMB (r = 0.72). The data suggest that 34DMHA is one of the useful indicators for biological monitoring of 124TMB exposure.


Formic acid excretion in comparison with methanol excretion in urine of workers occupationally exposed to methanol. A semiautomated head-space gas chromatographic (GC) method was developed for measuring formic acid in urine. The method consists of heating 1 ml urine sample in a 20-ml air-tight vial in the presence of 1 ml sulfuric acid and 2 ml ethanol at 60 degrees C for 30 min for ethyl esterification and air-liquid equilibrium, followed by automatic injection of 1 ml head-space air into a flame ionization detector GC. The detection limit was 1 mg/l for formic acid. The method was applied to measure formic acid in the shift-end urine samples from 88 workers exposed to methanol at 66.6 ppm (as geometric mean) and in urine samples from 149 nonexposed controls. Methanol concentrations were also determined. Regression analysis showed that urinary formic acid concentrations, as observed or corrected for either creatinine concentration or specific gravity of urine (1.016), correlated significantly with time-weighted average intensities of exposure to methanol vapor. Men excreted significantly more formic acid than women. Comparison with methanol excretion suggested, however, that urinary formic acid is less sensitive than urinary methanol as an indicator of methanol vapor exposure, primarily because the background level for formic acid (26 mg/l as arithmetic mean, or 23 mg/l as geometric mean) is more than ten times higher than the level for methanol (1.9 mg/l as arithmetic mean, or 1.7 mg/l as geometric mean). After theoretical methanol exposure at infinite concentration, the urinary formic acid/methanol ratio should be about 0.4.


Erythrocyte antioxidant system and serum ceruloplasmin levels in welders. The erythrocyte antioxidant system (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione) and serum ceruloplasmin were studied in workers chronically exposed to welding fumes and gases, which are thought to be oxidant pollutants. Fifty-four healthy men using two electric arc welding processes (manual metal arc on stainless steel and mild steel, and metal inert gas on mild steel) were studied. The possible effects of cigarette smoking were also considered. The erythrocyte antioxidant system was in the normal range for all welders. Serum ceruloplasmin was significantly enhanced only in smoking welders and higher in manual metal arc than in metal inert gas welders, suggesting that the increase is related to the severity of the oxidant threat, which is more stressful for the workers using the manual metal arc technique because of the presence of stainless steel particles in the fumes. Although cigarette smoking alone did not increase serum ceruloplasmin levels, it affected the response to oxidant stress in welders.


Serum fluoride as an indicator of occupational hydrofluoric acid exposure. To define the relationship between ionic fluoride concentration in the serum of workers and the amount of hydrofluoric acid (HF) in the work environment, pre-and postshift serum and urine samples of 142 HF workers and 270 unexposed workers were examined. The maximum and minimum concentrations of HF in the air in each workshop varied from the mean by less than 30%. The preexposure levels of serum and urinary fluoride in HF workers were higher (P < 0.001) than the control values. This suggests that fluoride excretion from the body continues for at least 12h. The postshift serum and urinary fluoride concentrations of these workers were significantly higher (P < 0.001) than the preshift concentrations. A good correlation (r = 0.64) was obtained between postshift serum fluoride and postshift urine fluoride. There was a linear relationship between mean serum fluoride concentration and HF concentration in the workshop. A mean fluoride concentration of 82.3 micrograms/l with a lower fiducial limit (95%, P = 0.05) of 57.9 micrograms/l was estimated to correspond to an atmospheric HF concentration of 3 ppm. This is the maximum allowable environmental concentration recommended by the Japanese Association of Industrial Health, and it is also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results demonstrate that exposure to HF can be monitored by determining the serum fluoride concentration.


Symptoms of construction workers exposed to whole body vibration and local vibration. To study the effects of construction machinery operation on subjective symptoms, a questionnaire survey was carried out among construction machinery operators by a self-reporting method. Subjects were 184 power shovel operators, 127 bulldozer operators, 44 forklift operators as operator groups, and 44 office workers as a control. Their ages were in a range of 30-49 years. The questionnaire contained 20 symptoms referring to fatigue, digestive problems, and upper or lower limbs or back problems. The prevalence rate and symptom characteristics were examined. The dominant symptoms of the operator groups were stiff shoulder, low back pain, and stomach symptoms. The prevalence rate of low back pain was significantly different between forklift operators and controls. No significant differences were found in the symptoms of upper limbs and fingers between operator groups and controls. The prevalence of Raynaud's phenomenon was 0.5%-2.3% in the operator groups and 2.3% in the control group.


Neurotoxicity of solvent mixtures in spray painters. I. Study design, workplace exposure, and questionnaire. A multidisciplinary cross-sectional study was carried out in 105 spray painters with long-term solvent exposure (10-44 years) and in 58 control subjects not exposed to solvents. By means of air monitoring the solvent concentrations in the ambient air during spray painting were determined using charcoal and silicagel tubes with pumps and passive samplers. In general, the air concentrations of the individual compounds did not exceed the current limit values (MAK values). Aromatic hydrocarbons like toluene, xylene, ethylbenzene, trimethylbenzene, aliphatic hydrocarbons (e.g., heptane) and acetates (ethylacetate, butylacetate) were determined to be important components of paint solvents. However, in unfavorable work conditions the "exposure index" could exceed the permissible limits two or three times. To assess the body solvent load at the time of examination, biological monitoring (BM) was performed. The main finding was that there was no evidence of neurotoxicologically relevant solvent exposure. Only in the case of methyl hippuric acid in urine spot samples did the spray painters show a higher mean value (80 mg/l) than control subjects (below 20 mg/l), indicating recent xylene exposure. Elevated urinary chromium concentrations (maximum value 29 micrograms/l) were found in 28 spray painters as a result of using zinc chromate-containing wash primers without taking protective measures. To assess the degree of past solvent exposure a special questionnaire was used. This included variables like duration and amount of solvent exposure, the presence of a technical ventilation system, health complaints during painting, etc. Additionally, three "solvent exposure indices'' (SEI) were calculated and used for evaluation of "dose-effect relationships.''(ABSTRACT TRUNCATED AT 250 WORDS)


Human inhalation pharmacokinetics of chlorodifluoromethane (HCFC22). Two groups of three male volunteers were exposed to atmospheric concentrations of either 327 or 1833 mg m-3 chlorodifluoromethane (HCFC22) for 4 h. Blood, urine and expired air samples were taken during and after the exposure period and analysed for HCFC22. Urine samples were also analysed for fluoride ion. During the exposure period, blood concentrations of HCFC22 approached a plateau, and the average peak blood concentrations of 0.25 and 1.36 micrograms cm-3 were proportional to dose. HCFC22 concentrations in expired air were similar to the exposure concentration during the exposure period. The ratio between venous blood and breath concentrations of HCFC22 towards the end of the exposure period was on average 0.77, which is consistent with in vitro estimates of the partition coefficient. In the post-exposure period, three phases for the elimination of HCFC22 were identified, with estimated half-lives of 0.005, 0.2 and 2.6h. HCFC22 was detected in urine samples taken in the post-exposure period, and the rate of decline was consistent with the terminal rate of elimination estimated from blood and breath measurements. On average 2.1% of the inhaled HCFC22 was recovered in breath within 26 h of exposure. This is consistent with the low solubility in blood and fat. Minimal changes in fluoride ion concentrations in urine following exposure indicate that HCFC22 is unlikely to be metabolised to a significant extent. Following inhalational exposure HCFC22 is poorly absorbed and is rapidly eliminated from the body. Possible biological monitoring strategies could be based on measurements of HCFC22 in urine or breath samples collected after the end of an exposure period.


Anaerobic and aerobic power in arms and legs of elite senior wrestlers. The purpose of this study was to characterize anaerobic power and aerobic power (power at peak oxygen uptake, or peak VO2) of elite senior (post-collegiate) wrestlers. Subjects (n = 14) from the U.S. national senior freestyle and Greco Roman wrestling teams were evaluated at separate tests using cycle ergometry for peak VO2 of the arms, peak VO2 of the legs, arm anaerobic peak power, and leg anaerobic peak power. Power output at peak VO2 was recorded for each test and compared to the anaerobic power of the appropriate body segment. The results (mean +/- SD) showed that wrestlers produced 2.3 +/- 0.4 W.kg body weight-1 at arm peak VO2 (43.7 +/- 4.6 ml.kg body weight-1. min-1), 4.2 +/- 0.5 W.kg body weight-1 at leg peak VO2 (50.9 +/- 5.1 ml.kg body weight-1.min-1), arm PP of 7.7 +/- 1.0 W.kg body weight-1, and leg PP of 10.5 +/- 1.7 W.kg body weight-1. Comparing power output during anaerobic and aerobic tests, the subjects performed at 3.4 +/- 0.6 times their peak oxygen uptake during arm anaerobic ergometry, whereas leg anaerobic peak power was 2.7 +/- 0.4 times the power at peak oxygen uptake for the legs (p < 0.05 for difference between ratios). relative to aerobic power, elite senior wrestlers may produce power anaerobically in the upper body at significantly higher levels than in the lower body.


Neurotoxicity of solvent mixtures in spray painters. II. Neurologic, psychiatric, psychological, and neuroradiologic findings. A multidisciplinary cross-sectional study was performed to examine the chronic neurotoxicity of organic solvents. Participating in the study were 105 persons employed as spray painters and having long-term solvent exposure (10-44 years) and a control group consisting of 58 construction workers, electricians, and plumbers without occupational contact to solvents. Samples were matched for age, preexposure intelligence level, occupation, and socioeconomic status. After controlling for potentially non occupational confounding factors (neuropsychiatric diseases, metabolic disorders, high blood pressure, alcohol intake) 83 spray painters and 42 controls were entered finally into the study. The evaluation included work history, self-rating questionnaire, neurologic investigation, psychiatric analysis using the Present State Examination (PSE), psychological testing, and computerized axial tomography (CAT) of the brain. Physical and neurologic examinations demonstrated no case of overt disorders of the central or peripheral nervous system. An important result of the psychiatric analysis was that the syndromes "special features of depression" and "loss of interest and concentration" occurred significantly more frequently among spray painters than among controls. Further analyses demonstrated an association with chronic exposure over 30 years and repeated acute neurotoxic effects during solvent exposures. Neither psychological nor performance tests demonstrated any statistically significant differences in the performance sets after adjustment according to premorbid intelligence level; this finding supports the presumption of only a low grade of mental dysfunction. Correlation analyses indicated a relationship between subjective health complaints and long-term solvent exposure; however, the effect of age cannot be completely ruled out.(ABSTRACT TRUNCATED AT 250 WORDS)


A comparison of the blood lactate and plasma catecholamine thresholds in untrained male subjects. The relationships between the plasma epinephrine threshold (TE), the norepinephrine threshold (TNE), and the blood lactate threshold (Tlact) were examined during incremental cycling in 10 untrained male subjects. When oxygen uptake (VO2) measured at each threshold was expressed as a percent of VO2max, the thresholds occurred at 40.8 +/- 2.4%, 45.5 +/- 3.0%, and 46.6 +/- 3.0% for Tlact, TE, and TNE, respectively. The average VO2 and power output values obtained at the lactate and epinephrine thresholds were not found to be significantly different (p < 0.10). However, Tlact and TE occurred simultaneously in six subjects, whereas TE occurred at a higher work stage than Tlact in the other four subjects. The mean VO2 and power output values determined at TNE were found to be significantly greater than the values obtained at Tlact (p < 0.05). These two thresholds occurred together in four subjects, while TNE was observed to occur at a higher work stage than Tlact in the other six subjects. None of the differences between TE and TNE were significantly different. Although plasma norepinephrine concentrations were much greater than those for epinephrine at a given power output, the two catecholamine thresholds occurred simultaneously in seven subjects. The results are not consistent with the hypothesis that the increase in plasma catecholamine levels during incremental exercise is the sole determinant of the lactate threshold. It is also possible that a decrease in muscle pH, due to increased lactic acid, stimulated a reflex increase in sympathetic outflow and a subsequent rise in catecholamine levels.


Reliability of the rating of perceived exertion at ventilatory threshold in children. The purpose of this study was to examine the reliability of the rating of perceived exertion (RPE), using the Borg 6-20 scale, at ventilatory threshold (VT) in children. Thirty children (19 male, 11 female) with a mean +/- SD age of 10.4 +/- 1.1 yrs performed two graded exercise tests for the assessment of VT and VO2max. RPE was recorded throughout each exercise test. There were no significant (p > 0.05) differences between the mean VO2max (50.9 +/- 6.0 vs 51.0 +/- 5.7 ml.kg-1.min-1; r = 0.95) or the mean VO2 at VT (36.2 +/- 4.4 vs 36.7 +/- 4.5 ml.kg-1.min-1; r = 0.87) between trials. The mean RPE at VT during trial 1 (12.4 +/- 2.7) was significantly higher than during trial 2 (11.4 +/- 3.3; p < 0.05). The test-retest reliability correlation for the RPE at VT was r = 0.78. The lower RPE in the second trial may have been due to a greater comfort and familiarity with the testing procedures. The reliability analysis indicates that the RPE at VT within a given child is fairly consistent from trial to trial. However, large inter-individual variability in the RPE at VT (range = 6 to 19) was noted and was not related to variations in the onset of VT. This raises some concern over the use of a given RPE value or range of RPE values in the regulation of exercise intensity for this age group. The test-retest reliability of VT and VO2max in this age group is similar to previous reports.


Effect of short-term training cessation on performance measures in distance runners. This study examined if measures associated with distance running performance were affected by short-term (14 d) training cessation in 12 distance runners. VO2max decreased by approximately 3 ml.kg-1.min-1 (mean +/- SE, 61.6 +/- 2.0 vs 58.7 +/- 1.8 ml.kg-1.min-1, p < 0.05) with training cessation. Time to exhaustion (TTE) during the incremental VO2max test decreased by 1.2 min (13.0 +/- 0.5 vs 11.8 +/- 0.5 min, p < 0.001) and maximal heart rate increased (p < 0.001) by 9 beats per minute (BPM). No changes in running economy (75 and 90% VO2max) were evident, although submaximal heart rate increased by 11 BPM (p < 0.001) at both running speeds. Other evidence for detraining were decreases in estimated resting plasma volume (-5.1 +/- 1.9%) and muscle citrate synthase activity (-25.3 +/- 2.6%, p < 0.05). Muscular atrophy (muscle fiber cross-sectional area) was not evident. TTE and submaximal heart rate exhibited relatively large percent changes (-9 and +6%, respectively) compared to VO2max (-4%). These findings indicate that the reduction in VO2max with short-term training cessation is relatively small. TTE and submaximal heart rate may be easily measured, yet more sensitive indicators of decrements in distance running performance.


The effect of exercise training on salivary immunoglobulin A and cortisol responses to maximal exercise. The salivary immunoglobulin A (s-IgA) and cortisol responses to maximal exercise were examined in 24 adult males (X +/- SD; 22.1 +/- 3.0 yrs) before and after 10 weeks of run training. The subjects performed an incremental treadmill test to exhaustion and were randomly assigned to one of three groups: control (CON; n = 5), low intensity training (LO; n = 8), or high intensity training (HI; n = 11). Following the ten weeks of training, the subjects performed a second maximal treadmill test. Saliva samples were collected before, as well as immediately and 1 hr following each of the maximal treadmill tests and were analyzed for s-IgA and salivary cortisol. Maximal oxygen consumption (VO2max) increased significantly (p < 0.05) in the LO and HI groups but remained unchanged in the CON group. The s-IgA levels decreased significantly (p < 0.05) immediately post-exercise but returned to pre-exercise levels by one hour recovery. In addition, s-IgA and cortisol levels were not significantly (p > 0.05) correlated at any of the sampling times. These findings indicated that the s-IgA response to maximal exercise was unaffected by moderate (70% of VO2 max) to heavy (86% of VO2max) training (designed to develop cardiorespiratory fitness in healthy non-athletic adults) and independent of salivary cortisol.


Gastric emptying of carbohydrate--medium chain triglyceride suspensions at rest. Nine male volunteers participated in 4 gastric emptying (GE) tests of liquid equicaloric mixtures of CHO (maltodextrins) and MCT of the following composition (% CHO-% MCT): Drink (Dr) 1:70%-30%, Dr2: 80%-20%, Dr3: 90%-10%, Dr4: 100%-0%. GE was measured at rest for 90 min according to the modified double sampling technique. GE rate, expressed as t1/2 (SEM), was 23 (2.3), 24 (1.6), 27 (2.2) and 36 (2.9) min, respectively, from drink 1 to drink 4. Statistical analysis showed that all MCT containing drinks emptied faster than the 100% CHO drink. Two mechanisms may explain this observation: 1) the CHO content and osmolality increases from Dr 1 to Dr 4 (both are regulators of GE); 2) MCT may not inhibit GE as common fat does, due to a better water solubility and absorption in the small intestine, resulting in a decreased duodenal-gastric feedback.


Food-dependent exercise-induced anaphylaxis: report of two cases. Exercise-induced anaphylaxis (EIAn) is a rare condition characterized by giant urticaria, angioedema and acute gastrointestinal symptoms that develops on exertion. In the most severe forms it may be associated with acute cardiorespiratory symptoms (laringeal stridor, wheezing), profound hypotension or syncope. In some individuals, EIAn characteristically occurs after a meal suggesting that the anaphylactic reaction is provoked by both exercise and ingestion of a foodstuff to which the patient has become sensitized. Two representative cases of severe food-dependent EIAn are described, which emphasize the need of performing a careful allergological evaluation in sportsmen with unexplained cardiovascular and/or respiratory symptoms during effort, especially when associated with other allergic manifestations and/or occurring in the post-prandial period.


Influence of calf muscle contractions on blood flow parameters measured in the arteria femoralis. Ten healthy male subjects performed single (< 1 s), sustained and intermittent plantarflexions (up to 40 s) of one foot in sitting exercise position. Two different absolute forces were applied, which, in terms of maximal voluntary contraction, ranged between 5%-10% and 25%-30%. Blood velocity was continuously recorded in the proximal arteria femoralis by means of the Doppler technique. Heart rate (HR) and mean blood pressure (BP) were simultaneously determined using standard ECG and the FINAPRES method. Despite the distance between the proximal arteria femoralis and the exercising muscle the Doppler data showed: effects of single contractions on the individual Doppler data, the influence of consecutive contractions, variation with exercise intensity and differences between sustained and intermittent contractions. In all exercise tests there was an immediate significant increase in blood velocity at the onset of exercise. The major part (range 52%-73%) of the response to the 40 s tests was seen during the first 6 s. It was followed by a second phase of adjustment which depended on the type of exercise and exercise intensity. The single plantarflexion provoked increases in blood velocity for about 20 s. A comparison of HR and BP tracings with the Doppler data demonstrated the importance of local mechanical factors for the perfusion of the exercising muscle. The early adjustment of muscle perfusion were not correlated to the systemic blood pressure and, therefore, appeared to be related to muscle pump effects. The subsequent flow values were influenced by passive vessel compression and changes in local vasomotor tone.(ABSTRACT TRUNCATED AT 250 WORDS)


Soundmyogram analysis during sustained maximal voluntary contraction in sprinters and long distance runners. The aim of this study was to describe the influence of the different fiber type composition of the vastus lateralis muscle on the soundmyogram (SMG) time and frequency domain characteristics. The SMG was recorded from the vastus lateralis belly during exhausting maximal voluntary contraction (MVC) of the leg extensors in 7 sprinters (SPR) and 7 long distance runners (LDR). Seven sedentary males (SED) were investigated in the same experimental conditions. In the SPR the effort time was shorter and the MVC was greater while the SMG root mean square and the SMG frequency content, at the onset of contraction, were higher than in the SED and LDR, respectively. Throughout exertion the SMG RMS showed clear reduction for SPR and SED only and the SMG power spectra presented a compression towards the lower frequencies. The reported phenomena were less pronounced in the LDR than in SPR and SED. These results can be explained when the differences in the % of fast twitch fibers area, belonging to stronger and more fatiguing F motor units, in the three groups of subjects are considered and suggest that SMG characteristics reflect the muscle fiber typing.


Left ventricular filling behaviour in ultra endurance and amateur athletes: a stress Doppler-echo study. To evaluate the impact of different training levels on left ventricular (LV) filling dynamics, Doppler mitral flow was derived in 25 amateur endurance-trained athletes (amateurs) aged 31 +/- 9 years, with a personal marathon record > 200 min, and in 26 ultra endurance athletes (top athletes) aged 32 +/- 8 years, with a personal marathon record < 170 min, during bicycle exercise in supine position. In particular atrial filling fraction as the relative share of atrial contribution to LV filling was measured. During exercise (150 watt) atrial filling fraction increased significantly more in amateurs from 25% to 34% compared to top athletes from 25% to 29% (p < 0.001). Two min post exercise atrial filling fraction already reached baseline values in top athletes (25%), while it remained significantly elevated in amateurs compared to baseline values (29%, p < 0.001). Only ten min post exercise atrial filling fraction showed baseline values in amateurs (26%). Rate pressure product was not significantly different at all levels of exercise. Thus, while atrial filling fraction rose in both study groups during exercise, it returned earlier to baseline values in top athletes than in amateurs. This indicates a better cardiac adaptation to physical stress and a better diastolic performance during exercise in endurance athletes with a higher training level.


Is range of motion of the hip and ankle joint related to running injuries? A case control study. This study concerns a case-control study on the relation between range of motion (ROM) of the hip and ankle joints and running injuries. Sixteen male runners who had sustained a medically treated running injury during the year prior to the ROM measurements were matched for weekly running distance and age with sixteen male runners who had not sustained such an injury. All subjects were fit at the time of measurement. ROM was measured by standardized goniometry after a warm-up on a cycle-ergometer. Within non-injured subjects all goniometric measurements showed no significant (p > 0.05) differences between the left and right side of the body. Within injured subjects all goniometric measurements showed no significant (p > 0.05) differences between the injured and non-injured side of the body. Runners who had sustained a running injury showed a significant (p > 0.001) more restricted ROM of the hip joints (average ROM value 59.4 degrees +/- 8.0 degrees) in comparison to runners who had no been injured during the same period (average value ROM 68.1 degrees +/- 5.2 degrees). No such differences (p > 0.05) were found with regard to ankle ROM (average ROM value injured 12.8 degrees +/- 3.4 degrees and average ROM value non injured 14.0 degrees +/- 2.7 degrees). These findings suggest that ROM can be characterized as a more or less stable anthropometric trait.(ABSTRACT TRUNCATED AT 250 WORDS)


Mechanical ankle stabilisation due to the use of orthotic devices and peroneal muscle strength. An experimental investigation. The mechanical stabilising effect of different orthotic devices and artificially applied muscular strength to the peroneal muscles is tested in cadaveric ankle joints and in vivo. Both orthotic devices as well as muscular strengths of 150 N applied to the peroneal muscles can produce a significant reduction in mechanical ankle instability. However, none of these methods alone can stabilise the ankle joint in such way to completely normalise the talar tilt and anterior drawer sign that is found in stable ankle joints. In contrast to that, clinical results in the treatment of sprained ankles with the application of an orthosis, additional muscular strengthening is the best treatment to achieve a sufficient mechanical ankle stability during the period of ligament healing. Additional factors influencing the mechanical ankle stability are supposed.


The significance of diagnostic imaging in acute and chronic brain damage in boxing. A prospective study in amateur boxing using magnetic resonance imaging (MRI). The significance and possible extent of structural damage to the central nervous system (CNS) due to boxing are investigated. Bleeding, especially microhematomas, is considered to be one probable cause of the chronic encephalopathy in boxers. In a prospective study, 13 amateur boxers were investigated with the help of MRI several times before and after their fights. The MRI investigations were accompanied by neurologic examinations before and after the fights. Among the 13 boxes, 5 demonstrated focal neurological signs following the fights, without evidence of small hematoma or other structural alterations. The number of head punches did not correlate with the occurrence of neurologic signs. These results indicate that up to now imaging methods cannot clarify the development of chronic encephalopathy.


Job roles of assistive technology service providers in the United States. The purpose of this study was to identify empirically the roles of assistive technology service providers in the United States. Via factor analysis, the following six job roles were identified: (a) Device Selection and Maintenance Activities, (b) Environmental Modification Activities, (c) Dissemination of Information on Assistive Technology Activities, (d) Evaluation of Suitability of Assistive Device Activities, (e) Administration Activities, and (f) Product Development Activities. The identified roles can provide a potential guide for the development of education or training curricula for assistive technology service providers. Those job role categories can be considered to be required areas of knowledge in a curriculum for assistive technology specialists. The identified roles can also be utilized to help define the profession of assistive technology. That definition could help guide the development of eligibility criterion and examination content for a credentialing programme for qualified assistive technology service providers in the future. A clear description of the job of assistive technology service providers can help administrators create needed positions within service delivery organizations such as state department of rehabilitation services and a rehabilitation hospital. The results could be valuable to the administrators responsible for setting job role criteria for assistive technology service providers. Such criteria are necessary for making effective hiring and employee evaluation decisions. In addition, the results can provide other professionals who utilize assistive technology services with an accurate picture of the services available from assistive technology service providers. When professionals on a rehabilitation team know what to expect of each other, clients are better served. Thus a better understanding of the roles of assistive technology service providers can contribute to better utilization of their services by a multidisciplinary team. This would in turn increase the chances of assistive technology services being offered to clients. Replication of the present study is encouraged to verify the obtained results. A future study should also focus on examining the roles of assistive technology service providers by directly observing their daily work activities. The task inventory used in the present study (ATTI) might be utilized to help guide such observations.


Tibia development in turkeys and chickens as affected by early-age feed restriction. Tibia development was studied by histomorphometry in male chickens and turkeys fed ad libitum throughout the growing period, or subjected to an early-age (1-week) severe feed restriction for 6 and 14 days, respectively. In turkeys, the rates of longitudinal bone growth and epiphyseal width growth, both dependent on the activity of chondrocytes, proceeded rapidly and reached maxima at early ages of 24 and 11 days, respectively. Moreover, longitudinal bone growth and the growth of epiphyseal width were reduced during early-age feed restriction, in both chickens and turkeys. On the other hand, the rate of growth of metaphyseal width, determined by activity of bone cells such as osteoclasts and osteoblasts, reached in turkeys a maximum at the relatively late age of 70 days, and was not influenced by feed restriction. Rhythmic variation characterized the temporal behavior of the height of the hypertrophic and non-hypertrophic zones of the growth plate, the trabecular width, and the osteoclasts number at the subchondral region. Rhythmicity appeared similar in both ad libitum-fed and early-age feed-restricted birds of both species. The height of the non-hypertrophic epiphyseal cartilage appeared not to change, whereas the hypertrophic zone decreased with age and early-age feed restriction, demonstrating the importance of cartilage cell hypertrophy as a main determinant of longitudinal bone growth. Sexual maturation was accompanied by the disappearance of both hypertrophic and non-hypertrophic zones of the epiphyseal growth plate and the end of bone elongation. Trabecular width at the end of bone elongation. Trabecular width at the subchondral region increased while osteoclast number decreased with age, reflecting the net increase in bone mass, but were not affected significantly by early age feed restriction. Compensatory growth of the early-age feed-restricted birds, resulted in the complete recovery of affected bone variables within a few weeks of resumed ad libitum feed intake.


Embryonic oxygen consumption and organ growth in the wedge-tailed shearwater. Embryonic oxygen consumption and organ growth were measured in the Wedge-tailed Shearwater (Puffinus pacificus), a tropical seabird characterized by slow embryonic growth and a prolonged pipping process prior to hatching. In most organs, growth in unpipped eggs could be represented by a linear regression of organ mass on whole-embryo mass. However, the slopes of the regression lines varied considerably between organs. The slope was steepest for the stomach and lowest in the heart and lungs. Oxygen consumption also increased linearly with embryo mass up to 25g in unpipped eggs, until just prior to pipping. In pipped eggs, however, there was a considerable increase in oxygen consumption, and acceleration of growth in some organs (eg. liver, intestine) while in others (eg. stomach, pectoral muscles, eyeballs) growth rates diminished. Comparison with the reported growth of other species revealed a number of similarities between the embryos of the semi-precocial shearwater and the precocial domestic fowl, together with several differences between the shearwater and the altricial pigeon embryo.


Expression of phosphatidylinositol-dependent phospholipase C sensitive Qa-2 antigen is increased on peripheral blood lymphocytes of aging mice. Qa-2 antigen, a nonclassical MHC antigen, is one of a group of cell surface antigens that may be anchored to the cell surface by a glycophosphatidylinositol (GPI) linkage rather than, as is the case with the classical MHC antigens, K, D, and L, by a transmembrane linkage. Recent studies have shown that T cells may be activated through the cross-linking of GPI anchored Qa-2 antigens by anti-Qa-2 antiserum. The Qa-2 antigens involved in signal transduction in activated T cells are sensitive to lipolytic cleavage by phosphatidylinositol-dependent-phospholipase C (PI-PLC). Since T cell function is known to decline with age, a study was undertaken to determine whether the relative amount of lipase sensitive Qa-2 antigen changes with age. Ficoll- Hypaque purified peripheral blood lymphocytes were obtained from C57BL/6 and A strain mice from 6-30 months of age. The cells were incubated with or without phosphatidylinositol- dependent-phospholipase C followed by incubation with anti-Qa-2 monoclonal antibodies and a fluorescein labeled second antibody. Analysis on a FACScan flow cytometer demonstrated that the A strain mice had a single population of Qa-2 positive lymphocytes which increased in lipase sensitivity with age. The C57BL/6 strain mice of all ages had two populations of Qa-2 positive cells, one staining with high fluorescence intensity (high antigen density) and the other with low fluorescence intensity (low antigen density). The proportion of cells found in the high density peak increased markedly with age, suggesting on overall increase in Qa-2 expression. In young animals, only the high density peak was sensitive to PI-PLC treatment. In older animals, the cells originally appearing in the high density population shifted to the low density population after treatment with PI-PLC, suggesting that there must be both lipase sensitive and lipase insensitive forms of Qa-2 present on lymphocytes in these aging C57BL/6 mice. Overall, these data suggest that the proportion of lymphocytes expressing lipase sensitive Qa-2 is increased on lymphocytes of old mice. Since a role for lipase sensitive GPI-linked Qa-2-antigen has recently been postulated in T cell activation, it is possible that the increased lipase sensitive Qa-2 antigen may play a role in age-related changes in T cell function.


Growth analysis by the first, second, and third derivatives of the Richards function. The Richards function serves as a tool for growth (W) analysis by means of absolute growth rate (AGR), i.e. dW/dt, and relative growth rate (RGR), i.e. d(loge W)/dt. More information may be gained using the second derivative d2W/dt2, and the third derivative d3W/dt3 of the Richards function to determine the times when the second derivative time curve achieves a maximum, minimum, and zero. The latter separates growth acceleration and retardation. Exponential growth occurs as long as (RGR)2 is less than the relative acceleration rate added to a tolerance value. This period of growth does not extend to the point of maximum acceleration of the growth curve. The points of maximum and minimum acceleration are at equal time distances from the point of inflection. A straight line phase of growth is approximated between the times when d2W/dt2 is maximum and minimum. Thus, a mathematical model for the analysis of aging changes is presented. Methodology described here should be applicable to any biological system or subsystem. As an application, derivatives of the Richards function are used to provide information on potato (Solanum tuberosum L.) tuber kinetics.


A mathematical analysis of human embryonic and fetal growth data. There is no set of growth data from a single source for the human embryo/fetus which spans the full range of pregnancy. For mathematical and statistical analysis of the full gestational period, it was necessary to pool data from several sources. Three growth equations, which have been reported in the literature for various purposes, were tested and compared for possible use as a tool to describe the growth of the human embryo/fetus. Parameters were estimated using statistical procedures on the pooled data for the Verhulst logistic equation, a polynomial equation, and the Gompertz equation. The polynomial and Gompertz equations provided the best fit for the growth of the normal human embryo/fetus over the broadest range of 25 to 300 days, and especially in the critical period of development (gestational days 40 to 70). The relative rate of growth of the embryo/fetus was about 15% per day on the 25th day and declined progressively thereafter; the absolute rate of growth was the greatest at about the 240th day.


Ontogenetic allometry of ossified fetal limb bones. The skeletal components of fetal limbs change in both size and shape throughout gestation. Relative growth of different bones, as well as differences between homologous bones of the upper and lower limbs, are not well known for all stages of fetal development. This study used human fetal skeletal material (N = 57) ranging in age from 19 to 40 weeks gestation, and in body mass from 290g to 4650g. Measurements of maximal length and minimal width were taken from the six major long bones: femur, tibia, fibula, humerus, radius, and ulna. These data were log transformed, and growth rates determined from least squares regression of bone length or bone width on body mass and on crown-to-rump length. The results indicated that growth rates are equivalent among bones within a limb, whereas homologous bones in the upper and lower limb grew at different rates. In general, the upper limb bones display negative allometry and the lower limb bones display isometric growth in relation to body mass and crown-to-rump length. Further, there was no difference between growth rates of length and width relative to body mass. The negative slopes of upper-to-lower limb bones in relation to mass confirm the conclusion that lower limb bones grow faster than the upper limb bones from 19 weeks gestation to birth. These results, together with results from similar studies of other periods of fetal development, provide a unified picture of the prenatal growth in human skeletal limbs.


A review of techniques for quantifying sexual size dimorphism. Previous studies of sexual size dimorphism (SSD) use a variety of size dimorphism indices (SDI's) to quantify SSD. We propose that a useful SDI should meet four criteria as follows; 1) it should be properly scaled, 2) it should have high intuitive value, 3) it should produce values with one sign, (positive) when sex A is larger than sex B, and the opposite sign when sex B is larger, and 4) it should produce values that are symmetric around a central value, preferably zero. Many previously published SDI's do not meet any of these criteria, and none meet more than three. We present an alternative SDI based on the mean size of the larger sex divided by the mean size of the smaller sex with the result arbitrarily defined as positive (minus one) when females are larger and negative (plus one) in the converse case. Careful selection of a primary size variable is crucial to meaningful interpretation of sexual size differences.


Comparison of excretory/secretory and circulating antigens of Toxoplasma gondii by enzyme immunoassay and immunoblotting. Toxoplasma gondii trophozoites (RH strain) were cultured in embryonic fibroblasts in order to study the kinetics of production of excretory/secretory antigens, and the results were compared to the production of circulating antigens in an in vivo mouse model. By capture-ELISA, excretory/secretory antigens were first detected on the fourth day of culture whereas circulating antigens were first detected 1 day after infection. Similar concentrations of antigens were detected in both models as evidenced by comparable absorbance values. By immunoblotting, the excretory/secretory antigens were also detected later compared to circulating antigens (day 4 vs day 1). Seven major polypeptides were detected in both antigen preparations, six of them having the same molecular mass (110, 75, 48, 30, 24 and 22 kDa).


Ultrastructure and histochemistry of the digestive tract of juvenile Paramphistomum epiclitum (Paramphistomidae: Digenea) during migration in Indian ruminants. The digestive tract of juvenile Paramphistomum epiclitum consists of a foregut with a highly muscular terminal pharynx and an oesophagus, which leads to a pair of unbranched and blind-ending intestinal caeca. A syncytium lining the foregut is continuous with the external tegument and displays similar sensory papillae and secretory bodies (T1 and T2). A third type of secretory body (T3) is confined to the oesophageal cytons of newly excysted juveniles and is first evident in the syncytium by day 14 of migration. An epithelium lining the caeca is composed of a single layer of morphologically uniform cells whose apical surface is amplified by microvilli. Dense secretions synthesized in the caecal epithelium of mature cercariae are released during migration by a mechanism resembling modified apocrine discharge. The caecal epithelium of migrating juveniles undergoes a 10-fold increase in surface amplification (irrespective of growth) during its transition from a primarily secretory tissue to one apparently specialized for absorption.


Ultrastructure and histochemistry of the protonephridial system of juvenile Paramphistomum epiclitum and Fischoederius elongatus (Paramphistomidae: Digenea) during migration in Indian ruminants. The protonephridial system of juvenile Paramphistomum epiclitum and Fischoederius elongatus consists of a bilaterally symmetrical arrangement of primary, secondary and tertiary ducts which connect individual flame cells with a simple common bladder. Primary and secondary ducts are formed from columns of adjoining cells which provide an epithelial lining, whose luminal surface is elaborated with either short tubercles or lamellae. Groups of cilia project from the luminal surface at frequent intervals along secondary ducts. By contrast, the tertiary ducts and bladder are lined with a nucleated syncytium which ends at a junctional complex formed with the terminal canal. The latter is continuous with the tegumental syncytium and opens at a nephridiopore on the postero-dorsal surface. Tertiary ducts of mature cercariae contain concretions which are voided by migrating juveniles in whose tertiary ducts lipids are progressively accumulated. Evidence for the role of protonephridia in excretion and possibly in osmoregulation and ionic balance is currently examined.


Ultrastructure and histochemistry of the lymph system and parenchyma of juvenile paramphistomes (Paramphistomidae: Digenea) during migration in Indian ruminants. The lymph system of juvenile Paramphistomum epiclitum and Fischoederius elongatus consists of a single pair of longitudinal primary vessels from which sub-dividing branches extend laterally to associate with most major tissues and organs. The system originates shortly after excystation in the definitive host and is fully developed in day 14 juveniles. Lymph vessels are syncytial and membrane limited, with a matrix which contains autophagic-like inclusions, clusters of SER and free nuclei. Similar organelles are evident in the matrix of parenchyma and specialized cells juxta-posing the pharynx (JP cells). These tissues are intimately associated and perhaps functionally integrated. Parenchyma represents a major site for carbohydrate storage and turnover, whilst the lymph appears to perform a similar role for proteins. The JP cells of juveniles display prolific autophagic-like activity only during migration, which coincides with the depletion of carbohydrate reserves in parenchyma. Key mitochondrial enzymes were histochemically demonstrated in the lymph despite the apparent absence of mitochondria from this system in post-day 14 juveniles. Succinate dehydrogenase activity was cytolocalized in mitochondria, whilst attempts to perform a similar localization of this enzyme in lymph were unsuccessful. The possibility of non-enzymatic interference in the histochemical demonstration of dehydrogenase is examined.


Application of a simple culture of Plasmodium berghei for assessment of antiparasitic activity. Mouse erythrocytes infected with Plasmodium berghei were incubated for a short period in microplate wells. The parasites changed morphologically from the immature ring form to mature schizonts, and free merozoites were released. However, reinvasion of the erythrocytes appeared not to be possible in this system. This intraerythrocytic one-step growth of the parasite could be determined quantitatively by counting incorporation of 3H-hypoxanthine. The incorporation was markedly decreased by addition of certain antiparasitic agents to the culture. The sensitivity of this growth inhibition test was comparable to or higher than the mouse protection test. The results suggested the practical utility of this simple assay in screening antimalarial activity.


Cross-reactivity between Necator americanus and Schistosoma mansoni in mice. Poly-parasitism is common in endemic communities and reactivity of sera from hookworm-infected patients against schistosomular antigens has been reported. Protective cross-immunity between N. americanus and S. mansoni was investigated in NIH and BALB/c mice. Protective resistance to homologous challenge with both parasites was confirmed in this model, however, functional immunity to heterologous challenge was not demonstrated. Sera from animals which had received homologous challenge with N. americanus and from hookworm-infected mice, which had previously been exposed to radiation-attenuated S. mansoni, exhibited an enhanced IgGAM response to infective stage N. americanus somatic antigens. The implications of these results with respect to serodiagnosis are discussed.


Towards a suitable antigen for diagnosis of Gnathostoma spinigerum infection. Advanced third-stage larvae of G. spinigerum were obtained from two separate sources, namely from cysts in the livers of naturally infected eels (L3E) and from experimentally infected mice (L3M). Morphology of the L3E was studied microscopically. The larvae were homogenized in distilled water, 1% Triton X-100 or 1% sodium deoxycholate containing protease inhibitors. Protein compositions of the three crude extracts were compared, on the same weight basis, by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie brilliant blue staining while their antigenicities were studied by Western blot analysis using serum of a patient with parasitologically confirmed gnathostomiasis. Distilled water was found to be the best extraction solution in solubilizing proteins especially the diagnostic antigen, namely the 24,000 (24 kDa) mol. wt component from the larvae. The L3E and L3M contained relatively equal amounts of the 24 kDa antigen. This diagnostic component was anatomically located in the body fluid, oesophagus and intestine of the larva.


Mannitol metabolism in Eimeria tenella.

Mannitol metabolism in Eimeria tenella. Unsporulated oocysts of Eimeria tenella contain large quantities of carbohydrates, namely amylopectin, mannitol and glucose. Analysis of carbohydrate content of sporulating oocysts revealed that mannitol content increased markedly during early stages of sporogony (first 4-6h) but slowly diminished during the next 40h of sporulation. Accumulation of mannitol was accompanied by a rapid decrease in amylopectin and free glucose, suggesting that mannitol might be synthesized from glucose released from amylopectin. Mannitol was also detected in sporozoite and merozoite extracts. All four mannitol cycle enzymes were detected in oocysts. Sporozoites excysted in vitro had lower activities of all four enzymes. Mannitol-1-phosphatase and mannitol dehydrogenase activity was also detected in merozoites obtained from the second stage schizonts. Sporozoites incubated with 14C-glucose accumulated radioactively labelled precursor continuously for over 12h and some of the 14C-glucose was converted into 14C-mannitol. These results indicate that mannitol plays an important role in the metabolism and development of the intracellular stages of the parasite.


Millardia meltada, a new host for Acanthocheilonema viteae and a simple technique for separation of microfilariae from peripheral blood. Millardia meltada were infected with Acanthocheilonema viteae and examined for their susceptibility. The morbidity of infected M. meltada was low compared with that of jirds. On day 47 post-infection (p.i.), 13 of 14 M. meltada developed microfilaremia. Male M. meltada then showed gradually increasing microfilaremia with a peak level of 7000 per 30 microliters blood at week 20 p.i., which was much higher than that (3000) of male jirds. In contrast, microfilarial densities of female M. meltada were markedly low with a peak level of 200 during weeks 10-12 p.i. A simple centrifugation technique with Lympholyte-M was devised for microfilarial separation from the peripheral blood of infected M. meltada and yielded approximately 17 x 10(5) viable microfilariae from 1 ml of blood. This method also makes it possible to collect microfilariae from the same individuals repeatedly. M. meltada, coupled with this microfilarial separation technique, serves as a useful animal model for microfilarial studies of A. viteae.


The sheep antibody response to repeated infection with Lucilia cuprina. The specific serum antibody responses of sheep exposed to 10 consecutive infections of L. cuprina have been analysed by enzyme-linked immuno-sorbent assay and immunoblotting using monoclonal antibodies specific for sheep immunoglobulin isotypes. Recognition of a number of larval excretory-secretory products by IgM antibodies appeared to be non-specific. IgG1 was the major antibody class stimulated by the infection protocol and marked increases in antibody to specific excretory-secretory antigens were observed. Three molecules of 35, 30 and 25 kDa were particularly recognized although the extent of recognition of these molecules varied considerably between individual sheep serum. A pooled serum composed of sera collected after five to seven infections significantly inhibited larval growth in in vitro cultures when compared to a sera pool consisting of sera collected both prior to infection and after infections 1 and 2. The degree of inhibition was greater when serum with high specific antibody titre was used.


Hypersensitivity responses and repeated infections with Lucilia cuprina, the sheep blowfly. Sheep repeatedly infected with L. cuprina at 2- but not 4-week intervals developed partial resistance to infection after five infections, as measured by larval recovery. However, resistance did not persist for more than three infections. Skin weal responses were measured after injection of larval products simultaneously with each infection. The only correlation between weal size and larval recoveries occurred at infection 1 and indicated a relationship between skin sensitivity and innate rather than acquired resistance. The results suggest that resistance to L. cuprina can develop after repeated infections but that it is short lived and requires frequent larval exposure. A role for hypersensitivity responses was not confirmed by the weal responses but was suggested by the size of wound developed per larva recovered.


A new simplified assay for larval migration inhibition. A simple method is described for the in vitro detection of substances that impair the motility of third-stage larvae of gastro-intestinal nematodes. The test is based on the ability of larvae to freely migrate through selected mesh sizes of nylon sieves and the reduced ability of larvae to migrate after preincubation with, and in the presence of, substances that inhibit or reduce larval motility.


Cloning and partial nucleotide sequence of Schistosoma japonicum paramyosin: a potential vaccine candidate against schistosomiasis. Paramyosin from the blood fluke, Schistosoma mansoni, has shown promise as a vaccine candidate for schistosomiasis mansoni. Here we report the cloning and partial nucleotide sequence of a cDNA encoding paramyosin from the related human parasite, Schistosoma japonicum. Affinity purified antibodies to this clone recognized a S. japonicum antigen of molecular weight 97 kDa, equivalent to the reported size of S. mansoni paramyosin. Alignment of the cDNA sequence with that of S. mansoni paramyosin revealed 90% identity. Comparison of the predicted amino acid sequences revealed 95% identity. Although these two parasites differ in many characteristics, the substantial homology demonstrated here between S. mansoni and S. japonicum paramyosin could have important implications for the development of a S. japonicum vaccine.


Detection of pathogenic Entamoeba histolytica DNA in liver abscess fluid by polymerase chain reaction. A sensitive method for detection of pathogenic Entamoeba histolytica DNA in drained fluids from liver abscess patients, using the polymerase chain reaction (PCR), has been developed. The PCR employs oligonucleotide primers specific for the gene encoding the 30 kDa molecule of pathogenic E. histolytica. Liver abscess fluids (19 samples), from 14 patients with a presumptive amebic liver abscess, were examined microscopically and by the PCR method. Only two of the 19 samples were positive microscopically, whereas all 19 samples tested positive by PCR. This technique can be used to confirm the diagnosis of amebic liver abscess.