Elevated serum levels of TNF-alpha, sTNF-RI and sTNF-RII in murine schistosomiasis correlate with schistosome oviposition and circumoval granuloma formation.

Levels of circulating tumour necrosis factor (TNF-alpha) and its soluble receptors are elevated in chronic human schistosomiasis. However, the kinetics of TNF-alpha production and release of its soluble receptors have not been studied in humans or animals. Here we report on increased levels of TNF-alpha and its soluble receptors in murine schistosomiasis, beginning with schistosome oviposition and circumoval granuloma formation. TNF-alpha, sTNF-RI and sTNF-RII were measured in sera of mice infected with Schistosoma mansoni each week for 10 weeks postinfection. TNF-alpha levels increased gradually in all mice during the first 3 weeks. From 6th week postinfection, TNF-alpha levels in infected mice increased steadily, whereas those of uninfected mice remained essentially unchanged. sTNF-RI levels fluctuated in all mice during the first 3 weeks, and increased in infected mice during the following 5 weeks. sTNF-RII levels were similar in all mice for the first 4 weeks but increased in infected mice throughout the remainder of the experimental period. These data may be helpful in understanding pathogenesis in schistosomiasis as TNF-alpha plays a crucial role in circumoval granuloma formation and adversely affects schistosome fecundity.

Significance of interferon-gamma in coronary artery bypass surgery.

BACKGROUND: Gamma interferon (IFN-gamma) is produced by activated natural killer and T cells under pathologic circumstances. The objective of our study was to compare the level of IFN-gamma in open and endoscopic methods of vein harvesting for coronary artery bypass surgery (CABG). METHOD: Ninety samples of human saphenous veins harvested from patients prepared for CABG. Pre- and post-procedure sera of the patients, in addition to supernatants of 3-day endothelial cell culture, were analyzed for IFN-gamma. RESULTS: The mean preoperative IFN-gamma level (0.09+/-0.03 pg/mL) and that for postoperative sera (0.08+/-0.02 pg/mL) were not significantly different (P = 0.2). The mean IFN-gamma level in endothelial cell culture from the endoscopic (0.18+/-0.21 pg/mL) and the open method (0.19+/-0.39 pg/mL) were not significant (P = 0.89). CONCLUSION: We recommend the endoscopic method of vein harvesting because of its lower morbidity and earlier hospital discharge.

Intercellular and vascular cell adhesion molecule levels in endoscopic and open saphenous vein harvesting for coronary artery bypass surgery.

BACKGROUND: Numbers of intercellular and vascular cell adhesion molecules (ICAM and VCAM) and major ligands on endothelial cells for adherence of activated polymorphnuclear leukocytes, macrophages, and lymphoid cells increase in many inflammatory disorders and after trauma to different tissues. METHODS: Samples of human saphenous veins were harvested from 90 randomly selected patients who underwent coronary artery bypass graft (CABG) surgery, utilizing two different techniques (open and endoscopic). Endothelial cells were collected from the vein samples and cultured for 72 hours. Pre- and postoperative sera, in addition to the supernatants from the cultures, were analyzed for ICAM-1 and VCAM-1 using enzyme-linked immunosorbent assay. RESULTS: Mean preoperative levels of ICAM-1 and VCAM-1 (0.95 +/- 0.58 ng/mL and 1.81 +/- 1.03 ng/mL, respectively) did not differ significantly from that of postoperative sera (0.98 +/- 0.451 ng/mL and 1.74 +/- 1.05 ng/mL, respectively) (p = 0.77 and p = 0.73, respectively). Mean ICAM-1 and VCAM-1 levels in endothelial cell culture supernatants did not differ significantly between the endoscopic (0.16 +/- 0.05 ng/mL and 0.23 +/- 0.10 ng/mL, respectively) and the open method (0.18 +/- 0.08 ng/mL and 0.30 +/- 0.27 ng/mL, respectively) (p = 0.19 and 0.13, respectively). CONCLUSION: Our findings indicate that endoscopic and open saphenectomies are technically comparable in their effects on ICAM-1 and VCAM-1 synthesis during saphenous vein harvesting for CABG. We recommend the endoscopic method for its low morbidity and earlier hospital discharge.

Cytokine variations in patients with hormone treated prostate cancer.

PURPOSE: We evaluated the immunological response in patients with hormone sensitive and refractory prostate cancer, and untreated benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Serum levels of pro-inflammatory and anti-inflammatory cytokines were measured by enzyme-linked immunosorbent assay in 3 groups of patients. The groups included 18 men with a mean age of 79 years who had hormone sensitive prostate cancer, mean prostate specific antigen (PSA) plus or minus standard deviation 1.03 +/- 2.65 ng./ml. and a mean of 35 months of treatment, 10 with a mean age of 86 years who had hormone refractory prostate cancer, mean PSA 27.52 +/- 42.23 ng./ml. and a mean of 42 months of treatment, and 19 with a mean age of 73 years who had BPH and mean PSA 3.37 +/- 2.47 ng./ml. Results were compared with those in 10 age matched, disease-free controls. In the hormone sensitive group PSA regressed to normal and there was clinical evidence of a response to hormone ablation therapy, including orchiectomy, luteinizing hormone releasing hormone analogue and androgen blockade. Hormone refractory cases had elevated PSA and/or clinical evidence of disease progression. RESULTS: Levels of the anti-inflammatory cytokines interleukin (IL)-4, IL-6 and IL-10 were significantly elevated in the hormone refractory group compared with values in the hormone sensitive group (p = 0.02, 0.01 and 0.0001, respectively). Abnormal anti-inflammatory cytokines in hormone resistant cases correlated with elevated PSA, while in the BPH group there was no significant difference from controls. Pro-inflammatory cytokines in the hormone sensitive and resistant groups were not significantly different from those in controls. CONCLUSIONS: Our study indicates that in hormone refractory prostate cancer a high level of the anti-inflammatory cytokines IL-4, IL-6 and IL-10 develops that is directly associated with elevated PSA. Changes in the level of anti-inflammatory cytokines when androgen independent cells exist may have an important role in the selection of a subset of hormone insensitive cells. These criteria may be used as a prognostic marker for the response to hormone ablation therapy in men with prostate cancer.

Immune response in patients with persistent candiduria and occult candidemia.

PURPOSE: We evaluated the immunological response in patients with persistent candiduria with or without occult candidemia. MATERIALS AND METHODS: Levels of Thl (pro-inflammatory interleukin [IL]-1, IL-2 and tumor necrosis factor-alpha) and Th2 (anti-inflammatory IL-4 and IL-10) cytokines were measured in the sera of patients with persistent candiduria. Polymerase chain reaction assessment of the 158 base pair candidal actin gene was used to detect Candida albicans in blood to identify occult candidemia. RESULTS: During a 14-month period 66 hospitalized patients with a mean age of 63 years (range 44 to 80) with persistent candiduria were evaluated. Occult candidemia developed in 27 patients (41%) as evidenced by detection of candidal actin gene in the sera by polymerase chain reaction. Risk factors included antibiotics in 27 patients (100%), central venous catheter in 22 (81%), urinary catheter in 21 (78%), total parenteral nutrition in 18 (66%), diabetes mellitus in 16 (59%) and abdominal surgery in 14 (52%). A total of 17 age matched patients with a mean age of 59 years hospitalized for elective general or vascular surgical procedures with no clinical or laboratory evidence of urinary or hematogenous fungal or bacterial infection served as controls. Serum levels of Th2 cytokines were elevated in 18 of 39 patients with persistent candiduria alone, and in 22 of 27 patients with candiduria and occult candidemia compared to controls (p<0.002). Th1 cytokines were within normal limits or slightly decreased in all patients with persistent candiduria with or without candidemia. CONCLUSIONS: These observations indicate that an abnormal immune response develops in patients with persistent candiduria with or without candidemia.

p53 gene transfer to the injured rat carotid artery decreases neointimal formation.

PURPOSE: We studied the effect of adenovirus-mediated p53 gene transfer on the injured rat carotid artery to determine its ability to decrease the formation of neointima. METHODS: In vivo gene transfer was used in isolated segments of balloon-injured rat carotid arteries. Genetically modified adenovirus containing the gene encoding for wild-type p53 (AdWTp53) was applied in three concentrations: 8 x 10(10), 1.6 x 10(10), and 8 x 10(9) pfu/mL. Control rats received either adenovirus null (AdNull), 8 x 10(10) pfu/mL, or Medium-199 solution (vehicle). Expression of p53 was determined 4 days after gene transfer by Western blotting. Neointimal formation was assessed after 14 days by harvesting carotid arteries and determining the intima/media (I/M) ratio based on cross-sectional area measurement. Simultaneously, immunohistochemistry was done to detect the presence of p53 on smooth muscle cell nuclei. RESULTS: P53 expression was confirmed by Western blotting. There was a significant reduction in neointimal formation on all treated animals compared with controls. The highest dose of AdWTp53 (8 x 10(10) pfu/mL) resulted in a near-total arrest of neointimal formation (I/M = 0.09 +/- 0.03, mean +/- SEM) with P <. 0001 versus vehicle (I/M = 2.23 +/- 0.15) or AdNull (I/M = 2.12 +/-. 12). The intermediate dose of AdWTp53 (1.6 x 10(10) pfu/mL) resulted in an I/M value of 1.04 +/- 0.18, with P <.001 versus vehicle and P =.001 versus AdNull. The lowest dose (8 x 10(9) pfu/mL) resulted in an I/M value of 1.12 +/- 0.18, with P <.001 versus vehicle and P <. 002 versus AdNull. The immunohistochemistry was positive for the presence of p53 in rats infected with AdWTp53. CONCLUSIONS: Adenovirus-mediated gene transfer of p53 protein significantly decreases the formation of neointima in the rat carotid injury model. This may represent a potential therapy for restenosis in humans.

Polymerase chain reaction used to detect candidemia in patients with candiduria.

OBJECTIVES: Candiduria has been shown to be an early marker of disseminated fungal infection in critically ill patients who have undergone surgery. The management of candidemia and disseminated candidiasis depends on rapid and definitive identification of Candida. Routine or fungus-specific blood cultures are unreliable and require a large quantity of blood for incubation. We describe the importance of the polymerase chain reaction (PCR) procedure in the early detection of candidemia in critically ill patients who develop candiduria and the favorable outcome in treating these patients with systemic antifungal therapy. METHODS: We compared the results of cultures and PCR to detect the presence of C. albicans in the blood of two critically ill patients with clinical candidiasis and candiduria. RESULTS: PCR detected the presence of C. albicans deoxyribonucleic acid (DNA) in urine and blood specimens of both patients in spite of negative blood cultures and did not detect fungal DNA after systemic antifungal therapy. CONCLUSIONS: Candiduria manifests as an early sign of candidemia, and systemic antifungal therapy timed appropriately based on the clinical condition and onset of candiduria will improve outcome. Detection of fungal DNA in blood by PCR is of value in establishing the diagnosis. Additional studies with a larger sample size are required to evaluate the specificity and sensitivity of PCR as a routine diagnostic test for candidemia.

Influenza virus vaccination of patients with multiple sclerosis.

Prior to vaccination with a trivalent influenza vaccine (AT/Texas, AB/Beijing, and BP/Panama), sera from 19 MS patients had a significantly higher mean level of antibody than 9 normal subjects to AT strain of influenza, but not to AB or BP strains. After Flu vaccination, the mean anti-AT and anti-AB antibody titers significantly increased 4-fold in 11 MS patients and 9 normal subjects. The ratio of MS responders (6/11), however, was lower than normal (8/9). The mean PBL proliferative response to the Flu antigens increased after vaccination significantly more in MS patients than in normal subjects, and increased in 9 of 11 MS patients and 3 of 9 normal subjects. Although MS patients responded to Flu antigens with higher antibody levels and proliferative responses of PBL, than normal subjects, a clinical protective effect of the vaccine against Flu was not clearly demonstrated in these patients, and vaccination did not cause or protect against exacerbation of MS.

Comparative study of biological glues: cryoprecipitate glue, two-component fibrin sealant, and "French" glue.

BACKGROUND: Although biological glues have been used clinically in cardiovascular operations, there are no comprehensive comparative studies to help clinicians select one glue over another. In this study we determined the efficacy in controlling suture line and surface bleeding and the biophysical properties of cryoprecipitate glue, two-component fibrin sealant, and "French" glue containing gelatin-resorcinol-formaldehyde-glutaraldehyde (GRFG). METHODS: Twenty-four dogs underwent a standardized atriotomy and aortotomy; the incisions were closed with interrupted 3-0 polypropylene sutures placed 3 mm apart. All dogs had a 3- by 3-cm area of the anterior wall of the right ventricle abraded until bleeding occurred. The animals were randomly allocated into four groups: in group 1 (n = 6) bleeding from the suture lines and from the epicardium was treated with cryoprecipitate glue; in group 2 (n = 6) bleeding was treated with two-component fibrin sealant; group 3 (n = 6) was treated with GRFG glue; group 4 (n = 6) was the untreated control group. The glues were also evaluated with regard to histomorphology, tensile strength, and virology. RESULTS: The cryoprecipitate glue and the two-component fibrin sealant glue were equally effective in controlling bleeding from the aortic and atrial suture lines. Although the GRFG glue slowed bleeding significantly at both sites compared to baseline, it did not provide total control. The control group required additional sutures to control bleeding. The cryoprecipitate glue and the two-component fibrin sealant provided a satisfactory clot in 3 to 4 seconds on the epicardium, whereas the GRFG glue generated a poor clot. There were minimal adhesions in the subpericardial space in the cryoprecipitate and the two-component fibrin sealant groups, whereas moderate-to-dense adhesions were present in the GRFG glue group at 6 weeks. The two-component fibrin sealant was completely reabsorbed by 10 days, but cryoprecipitate and GRFG glues were still present. On histologic examination, both fibrin glues exhibited minimal tissue reaction; in contrast, extensive fibroblastic proliferation was caused by the GRFG glue. The two-component and GRFG glues had outstanding adhesive property; in contrast, the cryoprecipitate glue did not show any adhesive power. The GRFG glue had a significantly greater tensile strength than the two-component fibrin sealant. Random samples from both cryoprecipitate and the two-component fibrin glue were free of hepatitis and retrovirus. CONCLUSIONS: The GRFG glue should be used as a tissue reinforcer; the two-component fibrin sealer is preferable when hemostatic action must be accompanied with mechanical barrier; and finally, the cryoprecipitate glue can be used when hemostatic action is the only requirement.

Production of anti-acetylcholine receptor-alpha antibody in vitro by peripheral blood lymphocytes of patients with myasthenia gravis: role of immunoregulatory T cells and monocytes.

To study the role of T cells in T and B cell interaction resulting in production of antibody (Ab) to the alpha chain of acetylcholine receptor (anti-AChR-alpha Ab) in myasthenia gravis (MG), we cocultured peripheral blood-purified B and T cells of patients with MG and of control subjects with and without multiple sclerosis in the presence of AChR-alpha or pokeweed mitogen. Under these conditions, a high level of anti-AChR-alpha Ab was produced by cells of patients with MG but not of control subjects. Production of anti-AChR-alpha Ab by B cells was stimulated by autologous purified or cloned CD4+ T cells, whereas autologous CD8+ T cells had no effect. CD8+ T cells did not suppress anti-AChR-alpha Ab production when added to B cells cocultured with CD4+ T cell clones. Anti-AChR-alpha Ab production was inhibited by monoclonal antibodies against CD4 and class II major histocompatibility complex (MHC) antigens, indicating that these antigens are required for productive T-B cell interactions resulting in anti-AChR-alpha Ab synthesis. Anti-AChR-alpha Ab production by peripheral blood lymphocytes of patients with MG was significantly lower than that by their purified or cloned T cells cultured with B cells. Cell-mixing experiments indicated that anti-AChR-alpha Ab synthesis was inhibited by monocytes. The prostaglandin synthetase inhibitor, indomethacin, partially restored the suppressive effect of monocytes on anti-AChR-alpha Ab synthesis. These results indicate that induction of anti-AChR-alpha Ab production by CD4+ T cell clones requires CD4 and class II MHC antigens and is inhibited by suppressor macrophages and not by CD8+ T cells.

Defective production of anti-inflammatory cytokine, TGF-beta by T cell lines of patients with active multiple sclerosis.

Activated T lymphocytes play an important role in the pathogenesis of multiple sclerosis (MS). These T cells secrete both pro- and anti-inflammatory cytokines. We have studied the production of these two kinds of cytokines by PBL of patients with MS and compared it with normal controls and other autoimmune diseases (OAD). PBL of 29 patients with MS, 14 patients with OAD, and 14 healthy normal controls were cultured for 5 wk. PBL of MS patients produced more pro-inflammatory cytokines, IL-2, IFN-gamma and TNF/lymphotoxin, and less anti-inflammatory cytokine, TGF-beta, during wk 2 to 4 in culture than PBL of normal controls. PBL of MS patients also produced more IL-2 and TNF/lymphotoxin than PBL of OAD patients. Decreased TGF-beta production by lymphocytes of patients with MS correlated directly with disease activity. MS patients with active disease produced less TGF-beta than MS patients with stable disease. The cells producing TGF-beta were primarily CD8+ T cells and CD45RA+T cells. These findings emphasize the complexity of immune response in MS patients and suggest that the increased production of pro-inflammatory cytokines by lymphocytes of patients with MS, combined with the decreased production of TGF-beta (anti-inflammatory cytokine), may play an important role in the mechanisms and manifestations of MS.

Presence of cross-reactive antibodies to HTLV-1 and absence of antigens in patients with multiple sclerosis.

Antibodies to HTLV-1, as determined by ELISA, were highly elevated in the serum samples of four out of four (100%) patients with TSP, moderately elevated in four out of four (100%) HTLV-1 carriers, slightly elevated in 12 out of 34 (35%) patients with MS, and absent from the serum samples of 34 normal subjects. Western blot analysis showed that the antibodies to HTLV-1 antigens in MS serum were heterogeneous. Cultivation of peripheral blood lymphocytes (PBLs) from patients with MS or normal subjects did not generate HTLV-1 core p19 antigen in the supernatant of culture medium, whereas cultivation of PBLs from patients with TSP and carriers of HTLV-1 generated core p19 antigen after 3 days for up to 28 days of cultivation. HTLV-1 antigens were also expressed on the surface of PBLs in three out of four patients with TSP and in two out of four HTLV-1 carriers on days 14 and 28 of cultivation, as measured by indirect immunofluorescence or alkaline phosphatase staining, but were not found in PBLs of any of 34 patients with MS or 34 normal subjects. The data indicate that although cross-reacting antibodies appear in the serum of some patients with MS, not enough evidence exists to suggest that HTLV-1 antigen is being produced in MS or that HTLV-1 plays a role in the pathogenesis of this disease.

Needlestick injury: blood, mononuclear cells, and acquired immunodeficiency syndrome.

INTRODUCTION: Because transmission of HIV to health care workers after needlestick injury has occurred mainly a result of deep insertion of large gauge needles, blood and viable mononuclear cells transferred after needlestick injury were measured. METHODS: Needles of 20 to 27 gauge were filled with HIV-1 seropositive blood and inserted through extracorporeal human skin or parafilm covering physiologic saline solution modified Drabkin's solution, or culture medium, or inserted directly into one of these fluids, to a depth of one third of the needle length (0.5 inch) for 1 second. Volume of blood transferred was measured by both modified Drabkin's method and by chromium 51 labeling of red blood cells. Transfer of viable mononuclear cells was measured by growth in culture medium containing autologous feeder cells. RESULTS: The volume of blood transferred from a needle passed through skin varied from 312 +/- 69 nl from a 20-gauge needle to 14 +/- 4 nl from a 27-gauge needle, as measured by modified Drabkin's technique, and from 404 +/- 80 nl to 12 +/- 3.1 nl, as measured by chromium 51 labeling of red blood cells. The volume of blood transferred from a needle passed through parafilm was twice that transferred through skin. The volume of blood transferred through skin was 40% that transferred directly into fluid not covered by any barrier; blood transferred through parafilm was 80% of that transferred directly. When needles containing blood were inserted into culture medium for 1 second in the absence of a barrier, at least one viable mononuclear cell was almost always transferred to fluid from all gauges of needle tested. Insertion of needles through skin prevented transfer of all viable mononuclear cells from only 3% to 5% of 20- to 23-gauge needles, and from 12% to 32% of 26- and 27-gauge needles. Parafilm was an even less effective barrier than skin. Insertion of needles through parafilm completely prevented transfer of viable mononuclear cells from no 20- to 23-gauge needles and from only 5% to 10% of 26- and 27-gauge needles. CONCLUSION: The volume of blood transferred after needle insertion through skin for 1 second varied with the gauge of the needle and was 30-fold higher from a 20-gauge than from a 27-gauge needle. Variable mononuclear cells were transmitted after insertion through skin from more than 95% of 20- to 23-gauge needles and from 68% to 88% of 26- and 27-gauge needles. Parafilm was less effective than skin in reducing transmission of blood and viable mononuclear cells.

Detection of HIV antibody and antigen (p24) in residual blood on needles and glass.

There is a significant rate of percutaneous injury with needles during the care of patients with acquired immunodeficiency syndrome (AIDS). Following puncture injury, it is recommended that the source of the contaminating blood be checked, and if human immunodeficiency virus-type 1- (HIV-1)-seropositive, zidovudine prophylaxis be considered. As the source of contaminating blood may be unknown, we studied the detectability of HIV-1 antibody and circulating antigen (p24) in the residual blood from needles and pieces of glass at various intervals following exposure to blood. The residual volume of blood remaining in needles varied from 183 +/- 50 microliters for a 20 G needle to 7.8 +/- 1 microliter for a 27 G needle, and the residual blood on small pieces of glass varied from 23 microliters for a piece weighing 558 mg to 2 microliters for a piece weighing 21 mg. Analysis of washed samples of residual blood from all 20 G through 26 G needles and from broken pieces of glass larger than 0.41 g that had been exposed to HIV-1-seropositive blood and left at room temperature for one hour, one day and one week resulted in positive tests for HIV-1 antibody by enzyme-linked immunosorbent assay (ELISA), immunofluorescence and Western blot assays. The circulating antigen was detected in residual blood of 20 G through 26 G needles, but not from contaminated pieces of glass. This technique could be applied to situations where a healthcare worker pricked him- or herself with a needle or with a piece of glass that had been contaminated with blood of unknown seroreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Mating preference inSchistosoma mansoni.

We investigated the suitability of an in vitro culture system for measurement of mating behavior ofSchistosoma mansoni. The criteria used to evaluate this system were the level of phosphorylated nucleotides, egg production, and mating status of parasites. The level of ATP, ADP, AMP, and G6-P was measured at different time intervals during cultivation of worm pairs and remained essentially the same as that of control worms for up to 6 days. Egg production was observed in this system during 19 days of cultivation. Peak egg production occurred on day 4 with 72% of the total eggs being laid during the first week of cultivation. The variability in the number of eggs produced by different pairs ofS. mansoni necessitated the selection and matching of tubes with the same number of eggs after 48 hr. This permitted the detection of small changes in egg production by decreasing intertube variation. Mating recognition between male and femaleS. mansoni was evaluated by culturing separated adult worms with their original partner or with a different partner. During the first 24 hr, mating occurred among a greater percentage of worm pairs comprised of their original partner than among worm pairs comprised of different partners (P < 0.001). After 48 and 72 hr of cultivation, these differences were not statistically significant. Similar results were obtained with a culture of mixed males and females. Two drugs were studied for their effects on the mating ofS. mansoni in vitro. Aminoglutethimide (AG) at a concentration of 1 × 10(-4) had no effect on the frequency of mating whereas diethyldithiocarbamate (DDC) completely inhibited mating at a concentration of 3 × 10(-6) M and reduced the level of ATP in these worms.

Extraction of intersexual chemoattractants fromSchistosoma mansoni.

FemaleSchistosoma mansoni and their excretory-secretory (ES) products were extracted with a series of solvents to provide fractions of varying polarity. These fractions were assayed for chemoattractivity to males in vitro. One major component of these mixtures was found to be nonattractive and was identified as cholesterol.n-Pentane- and ether-soluble fractions derived from ES products exhibited chemoattractive activity comparable to that possessed by whole-worm extracts, but appeared to be simpler mixtures.

In vitro orientation of maleSchistosoma mansoni to extracts derived from female schistosomes.

Chemical orientation of adult maleSchistosoma mansoni was studied during cultivation in vitro. Directional preference was assessed in culture vessels marked with compass coordinates by the application of circular statistics for determining clustering and orientation to a predicted direction. Organic solvent extracts of fresh female schistosomes and supernatant fluids from 72-hr cultures of female parasites were tested for potential chemotactic activity. Analysis showed significant (P < 0.05) directional preference and clustering of male worms towards test compounds at all time periods (24, 48, and 72 hr) with one mixture of female extracts and at one of three time periods with a second female extract. Male worms did not respond to ecdysone, cholesterol, or solvent controls by orienting in predicted direction, although clustering was observed on two of 12 occasions. These results indicate the presence of a chemoattractant compound(s) in female extracts.

Time-lapse video tape documentation of chemical orientation bySchistosoma mansoni in vitro.

In vitro, the opposite sexes ofS. mansoni are attracted to each other by some means of premating communication which culminates in aggregation and copulation of sexual pairs within 24 hr. The system used for time-lapse video tape documentation of worm sexual behavior in vitro is described and evidence of sexual chemoattraction is presented.

Pathology of larval Eustrongylides in the rabbit.

Three fishermen from Maryland who swallowed live bait-minnows developed severe abdominal pain within 24 hr; 2 required abdominal surgery. Larvae of the nematode Eustrongylides sp. were found in the peritoneal cavity of both (Guerin et al., 1982). In the current study, the lesions produced by Eustrongylides larvae were investigated in New Zealand white rabbits. None of these exhibited any signs of clinical illness; however, postmortem examination within 24 hr of inoculation revealed that larvae had migrated through the walls of the esophagus and stomach and viable larvae were recovered from the pleural and peritoneal cavities as well as from gastric contents. Necropsies performed at different intervals of time postinoculation showed that the migrating larvae had produced multi-focal peritonitis and multiple granulomata in the liver.