Prenatal ultrasound characterization of the suprarenal mass: distinction between neuroblastoma and subdiaphragmatic extralobar pulmonary sequestration

With the increased routine use of prenatal ultrasonography, subdiaphragmatic masses in the fetus are identified more frequently. Suprarenal masses often are presumed to be neuroblastoma and are removed surgically postnatally. We sought to better understand the natural history of subdiaphragmatic extralobar pulmonary sequestration, and to determine if subdiaphragmatic extralobar pulmonary sequestration can be distinguished preoperatively from neuroblastoma. The literature was reviewed for cases of prenatally diagnosed suprarenal masses that proved ultimately to be either subdiaphragmatic extralobar pulmonary sequestration or neuroblastoma. The distinguishing features of the two lesions were identified and an algorithm was created on the basis of these distinctions. Prenatally diagnosed subdiaphragmatic extralobar pulmonary sequestration is no longer rare, with one case being reported for every 2.5 cases of neuroblastoma. On prenatal ultrasonography subdiaphragmatic extralobar pulmonary sequestration usually is echogenic, is left-sided, and can be identified in the second trimester. Neuroblastoma is most often cystic, right-sided, and identified in the third trimester. In summary, subdiaphragmatic extralobar pulmonary sequestration must be considered in the differential diagnosis of the suprarenal mass identified on prenatal ultrasonography. Using the algorithm which we propose, the correct diagnosis can be determined prenatally in 95% of patients.

Quantitation of shock wave cavitation damage in vitro

Acoustic cavitation damage was quantitated using aluminum foil targets placed within 2-mL polypropylene cryovials. The vials contained various media tested for their potential to support cavitation and were exposed to shock waves using an unmodified Dornier HM3 lithotripter. Foil damage, expressed in terms of a "damage index," was measured from digitized light microscopy images by quantitating the spread of gray-scale histograms. Target sensitivity was demonstrated by reproducible dose-response curves over the range (1-200 shock waves) commonly used for in vitro cell injury studies. Increased shock wave repetition rate reduced the damage index. Untreated foils showed a very low damage index (0.001% +/- 0.001%), while treated foils submerged in Ringer buffer yielded significant damage (2.2% +/- 0.3%, p < 0.001). Degassing the buffer reduced damage to 0.3% +/- 0.1% (p < 0.001). Foils submerged in castor oil showed virtually no damage. These results implicate acoustic cavitation in target damage. Targets immersed in biological fluids (blood and urine) had significantly less damage than in Ringer. The effect of degassing was also evaluated in a red blood cell lysis assay. Hemoglobin release in degassed preparations was significantly reduced compared to nondegassed controls (p < 0.001) and correlated with reduced foil damage index in cell-free vials. These findings characterize a sensitive method to quantitate acoustic cavitation and implicate a role for cavitation in shock wave lithotripsy-induced cell lysis.

Ultrafast exciton relaxation in the B850 antenna complex of Rhodobacter sphaeroides

Spectral changes were measured with femtosecond resolution following low-intensity, broad-band excitation of the peripheral antenna complex of the purple photosynthetic bacterium Rhodobacter sphaeroides. Absorption anisotropy decays also were measured. We identified a 35-fs relaxation of the absorption and emission spectra of the excited state, as well as a 20-fs anisotropy decay. We interpret these results as interlevel relaxation and dephasing, respectively, of extensively delocalized exciton states of the circular bacteriochlorophyll aggregate.

The nursing triage process: a video review and a proposed audit tool

OBJECTIVE

To review the activity of the nurse triage process.

SETTING

The triage room for adults attending the accident and emergency department of the Cardiff Royal Infirmary.

METHODS

226 triage processes were videotaped over 31 h during July 1994. Activities were subsequently analysed using a specially designed chart.

RESULTS

Areas for improvement in staff communication skills and patient privacy were identified.

CONCLUSIONS

The use of video in the triage room allows assessment of the triage process and is a valuable aid to training. Additionally, a potential visual audit tool has been identified.

Interstitial laser coagulation of the prostate

Interstitial laser coagulation (ILC), is the interstitial application of laser energy to achieve tissue coagulation by a thermal process. This is achieved by implanting the laser delivery fiber directly into the target tissue and firing the laser. As a treatment for benign prostatic hyperplasia, ILC has been investigated and used clinically. ILC is efficacious, can be used under local anesthesia, and can be performed in the clinic. In the future, there may be a role for ILC of the prostate as firstline therapy in the treatment of symptoms of prostatism and bladder outlet obstruction.

Deflation techniques for faulty Foley catheter balloons: presentation of a cystoscopic technique

The Foley catheter is used for drainage of the urinary bladder in < or = 15% of hospitalized patients and is self-retained by an inflatable balloon mechanism. Faulty balloon deflation, which leads to a retained catheter, is a condition treated by the urologist. In this article we describe a cystoscopic approach to deflation, evaluation, and recovery of retained fragments; review the techniques for deflation; and provide an algorithm to approach the retained Foley catheter.

Efficacy of moxidectin pour-on against gastrointestinal nematodes and Dictyocaulus viviparus in cattle

Twenty crossbred beef heifer calves were used for an efficacy evaluation of 0.5% moxidectin pour-on against gastrointestinal nematodes and Dictyocaulus viviparus. The latter parasite and Bunostomum phlebotomum were the target species. The calves were exposed to natural infection on pasture from late September to December 22. Additionally, all calves were experimentally infected with B. phlebotomum at 71 and 29 days before treatment and with D. viviparus at 29 days before treatment. The 20 calves were randomly allocated into two groups of ten, based on presence of patent lungworm and hookworm infections on days -6 and -1. Treatments were as follows: Group A, moxidectin 0.5% pour-on (PO) at 500 micrograms kg-1 BW; Group B, moxidectin vehicle (controls) by PO application. General strongyle and hookworm egg counts and lungworm larval counts were reduced to zero at 13 days after moxidectin treatment; treatment effect was significant (P < 0.05) only for the strongyle and hookworm counts. Percentage reduction for adult hookworms and mature-immature adult lungworms was 100.0 and also for adults and L4 Haemonchus placei and Ostertagia ostertagi and Trichostrongylus axei adults, adult males of Cooperia pectinata and C. spatulata, and Oesophagostomum radiatum adults. Efficacy values for C. punctata adult males, Cooperia spp. adult females, and Cooperia spp. L4 were > 99.9%, > 99.9%, and 92.4%, respectively. All efficacy values were significant (alpha = 0.05, 1-sided) except for Cooperia spp. L4.

Pore-forming activity of Coxiella burnetii outer membrane protein oligomer comprised of 29.5- and 31-kDa polypeptides. Inhibition of porin activity by monoclonal antibodies 4E8 and 4D6

Envelopes of large-cell variant Coxiella burnetii, the agent of Q fever, were the starting material for purification of an outer membrane protein (OMP) oligomer with aggregate molecular mass of approximately 2 x 10(4) kDa. The oligomer was resistant to trypsin and dissociation by SDS at 100 degrees C. Reducing agents dissociated the oligomer into monomers of 29.5 and 31 kDa, which migrated as a doublet during SDS-polyacrylamide gel electrophoresis. Both monomers were reactive in an immunoblot assay with monoclonal antibodies (mAbs) 4E8 and 4D6, which were previously selected for their reactivity with purified and SDS-denatured 29.5 kDa protein. Proteoliposomes were functional in an equilibrium assay at pH 7 and a swelling assay at pH 7 and 4.5. The pores in proteoliposomes allowed the passage of arabinose, glucose, and sucrose, but restricted stachyose. Polyclonal antibodies to C. burnetii cells and the mAbs were able to bind C. burnetii at pH 7 and 4.5. The uptake of 14C-glucose at pH 4.5 was inhibited by polyclonal antibodies and mAbs after binding to cells at pH 7. The mAbs did not inhibit 14C-glucose uptake at pH 4.5 after binding to cells at pH 4.5. Although the mAbs bind C. burnetii porin epitopes before and after acid activation, the mAbs bound under acidic conditions were unable to inhibit porin function. The inhibition of porin channel function by mAbs confirms the role of porin as a permeability barrier for the subsequent active transport of glucose by C. burnetii. In another study, we showed that the 29.5 kDa OMP antigen induced active immunity against virulent challenge. This information, combined with the recent confirmation that porins are important antigens in the induction of specific protective immune responses against infection by gram-negative bacteria, suggests that humoral immunity directed against C. burnetii porins might play an important role in immunity against Q fever (human infection) and coxiellosis (animal infection), global enzootic diseases.

Apical membrane permeability of MDCK cells

The osmotic water permeability (Pf) and permeability to nonelectrolytes were determined for the apical membrane of clonal strain Madin-Darby canine kidney (MDCK) C12 cells cultured as cysts with the apical membrane facing the surrounding medium. Pf and solute permeabilities were calculated from the rate of volume change of cysts by digitizing images at 1-s intervals after instantaneous osmotic challenge. Image measurement was fully automated with the use of a program that separated the image of the cyst from the background by using adaptive intensity thresholding and shape analysis. Pf, calculated by curve fitting to the volume loss data, averaged 2.4 +/- 0.1 micron/s and was increased by addition of amphotericin B. The energy of activation for Pf was high (16.3 kcal/mol), and forskolin (50 microM) had no effect on Pf. Two populations of MDCK cysts were studied: those with two to three cells and those that appeared to be composed of only one cell. The Pf of multicell cysts was the same as single cell cysts, suggesting that paracellular water flow is not significant. Solute permeability was measured using paired osmotic challenges (sucrose and test solute) on the same cyst. Urea permeability was not different from zero, whereas the permeabilities of acetamide and formamide were consistent with their relative oil-water partition coefficients. Our data are similar to values from studies on the permeability properties of vesicles of water-tight epithelial apical membrane. The combination of the unique model of MDCK apical-out cysts and fully automated data analysis enabled determination of apical membrane permeability in intact epithelial cells with high precision.

Effects of hydrogen bonding to a bacteriochlorophyll-bacteriopheophytin dimer in reaction centers from Rhodobacter sphaeroides

The properties of the primary electron donor in reaction centers from Rhodobacter sphaeroides have been investigated in mutants containing a bacteriochlorophyll (BChl)--bacteriopheophytin (BPhe) dimer with and without hydrogen bonds to the conjugated carbonyl groups. The heterodimer mutation His M202 to Leu was combined with each of the following mutations: His L168 to Phe, which should remove an existing hydrogen bond to the BChl molecule; Leu L131 to His, which should add a hydrogen bond to the BChl molecule; and Leu M160 to His and Phe M197 to His, each of which should add a hydrogen bond to the BPhe molecule [Rautter, J., Lendzian, F., Schulz, C., Fetsch, A., Kuhn M., Lin, X., Williams, J. C., Allen J. P., & Lubitz, W. (1995) Biochemistry 34, 8130-8143]. Pigment extractions and Fourier transform Raman spectra confirm that all of the mutants contain a heterodimer. The bands in the resonance Raman spectra arising from the BPhe molecule, which is selectively enhanced, exhibit the shifts expected for the addition of a hydrogen bond to the 9-keto and 2-acetyl carbonyl groups. The oxidation--reduction midpoint potential of the donor is increased by approximately 85 mV by the addition of a hydrogen bond to the BChl molecule but is only increased by approximately 15 mV by the addition of a hydrogen bond to the BPhe molecule. An increase in the rate of charge recombination from the primary quinone is correlated with an increase in the midpoint potential. The yield of electron transfer to the primary quinone is 5-fold reduced for the mutants with a hydrogen bond to the BPhe molecule. Room- and low-temperature optical absorption spectra show small differences from the features that are typical for the heterodimer, except that a large increase in absorption is observed around 860-900 nm for the donor Qy band in the mutant that adds a hydrogen bond to the BChl molecule. The changes in the optical spectra and the yield of electron transfer are consistent with a model in which the addition of a hydrogen bond to the BChl molecule increases the energy of an internal charge transfer state while the addition to the BPhe molecule stabilizes this state. The results show that the properties of the heterodimer are different depending on which side is hydrogen-bonded and suggest that the hydrogen bonds alter the energy of the internal charge transfer state in a well-defined manner.

Differential effects of diabetes and glomerulonephritis on glomerular basement membrane composition

The hallmark of renal diseases involving the glomerulus is the presence of proteinuria. While the routes of pathogenesis of proteinuria have not been established, alterations in the barrier function of the glomerular basement membrane (GBM) have been implicated. We evaluated the effect of streptozotocin diabetes and passive Heymann nephritis (PHN) over time on the macromolecular composition of rat GBM to determine if changes in composition correlate with proteinuria. Six to twelve rats from each group (control, diabetic, and PHN) were sacrificed 1, 5, 28, 56, or 84 days after induction of disease. Identical amounts of GBM were subjected to a sequential extraction procedure, and type IV collagen, entactin, laminin, fibronectin, and anionic charge content were quantitated in the extracts. Type IV collagen and entactin content did not change with time or disease. Both laminin and fibronectin contents increased with time in GBM in all groups, but this increase was significantly greater in diabetic GBM. A significant decrease in anionic charge content of GBM coincided with the onset of albuminuria at Day 28 in diabetes, but no change was seen in PHN. In diabetic rats, the increase in laminin content over control preceded the onset of albuminuria, while the increase in fibronectin was not apparent until after albuminuria was present. In PHN, no differences in type IV collagen, entactin, laminin, fibronectin, or anionic charge content of GBM were found compared with control, even though profound albuminuria was evident from Day 5 through 84. Thus, while alterations in laminin and fibronectin content may contribute to the loss of glomerular permselectivity in streptozotocin diabetes, such changes apparently are not involved in PHN.

Energy trapping and detrapping by wild type and mutant reaction centers of purple non-sulfur bacteria

Time-correlated single photon counting was used to study energy trapping and detrapping kinetics at 295 K in Rhodobacter sphaeroides chromatophore membranes containing mutant reaction centers. The mutant reaction centers were expressed in a background strain of Rb. sphaeroides which contained only B880 antenna complexes and no B800-850 antenna complexes. The excited state decay times in the isolated reaction centers from these strains were previously shown to vary by roughly 15-fold, from 3.4 to 52 ps, due to differences in the charge separation rates in the different mutants (Allen and Williams (1995) J Bioenerg Biomembr 27: 275-283). In this study, measurements were also performed on wild type Rhodospirillum rubrum and Rb. sphaeroides B880 antenna-only mutant chromatophores for comparison. The emission kinetics in membranes containing mutant reaction centers was complex. The experimental data were analyzed in terms of a kinetic model that involved fast excitation migration between antenna complexes followed by reversible energy transfer to the reaction center and charge separation. Three emission time constants were identified by fitting the data to a sum of exponential decay components. They were assigned to trapping/quenching of antenna excitations by the reaction center, recombination of the P(+)H(-) charge-separated state of the reaction center reforming an emitting state, and emission from uncoupled antenna pigment-protein complexes. The first varied from 60 to 160 ps, depending on the reaction center mutation; the second was 200-300 ps, and the third was about 700 ps. The observed weak linear dependence of the trapping time on the primary charge separation time, together with the known sub-picosecond exciton migration time within the antenna, supports the concept that it is energy transfer from the antenna to the reaction center, rather than charge separation, that limits the overall energy trapping time in wild type chromatophores. The component due to charge recombination reforming the excited state is minor in wild type membranes, but increases substantially in mutants due to the decreasing free energy gap between the states P(*) and P(+)H(-).

Changes in spleen and thymus cell phenotypes in mice vaccinated with the Coxiella burnetii phase I whole-cell vaccine or the chloroform-methanol residue subunit vaccine

Lymphoid cell phenotypes within the spleen and thymus were analyzed to determine whether numerical or proportional changes in cell populations could account for the immunosuppression seen after vaccination of mice with inactivated phase I Coxiella burnetii whole-cell vaccine (WCI). Within 21 days of vaccination with WCI, there was a reduction in the percentage of splenic T cells and B cells while the numbers of thymic T cells and B cells increased. A substantial percentage of spleen cells did not bear typical T cell or B cell surface markers. In contrast, except for an early rise (by day 3) in the numbers of T and B cells, injecting the chloroform-methanol residue subunit-vaccine (CMR) caused no significant phenotypic changes of lymphoid cells in the spleen or thymus. The percentage of thymus cells bearing T cell phenotypes was similar in mice vaccinated with WCI or CMR. However, the total number of T cells in the thymus dramatically decreased in mice vaccinated with WCI. There was no correlation between the lymphocyte hyporesponsiveness to mitogens and WCI in vitro and the increased numbers of CD8-positive splenocytes. These results suggest that WCI vaccination caused dramatic changes in splenocyte and thymocyte lymphocyte populations and provide evidence for the more benign nature of the CMR vaccine.

Temperature dependence of the reorganization energy for charge recombination in the reaction center from Rhodobacter sphaeroides

The rate of charge recombination from the primary quinone to the bacteriochlorophyll dimer of the reaction center from the photosynthetic purple bacterium Rhodobacter sphaeroides has been investigated using time-resolved optical spectroscopy. Measurements were performed at temperatures from 293 to 10 K on reaction centers that have specific mutations that result in a range of 425-780 meV for the free energy difference of charge recombination compared to 520 meV for wild type [Lin, X., Murchison, H. A., Nagarajan, V., Parson, W. W., Allen, J. P., & Williams, J.C. (1994) Proc.Natl.Acad.Sci.U.S.A. 91, 10265-10269]. In all cases, the rate increased as the temperature decreased, although the details of the dependence were different for each mutant. The observed dependence of the rate upon temperature is modeled as arising principally from a several hundred meV change in reorganization energy. The relationships among the rate, temperature, and free energy differences can be well fit by a Marcus surface using two modes centered near 150 and 1600 cm(-1)with a total reorganization energy that decreases from 930 to 650 meV as the temperature decreases from 293 to 10 K. In the inverted region, where the driving force is greater than the reorganization energy, the rate is found to be approximately independent of the free energy difference. This is modeled as due to the additional coupling of high frequency modes to the reaction. An alternative model is also considered in which a 140 meV increase in the reorganization energy is matched by a 140 meV increase in the free energy difference as the temperature decreases. The possible role of solvent dipoles in determining this temperature dependence of the reorganization energy and the implications for other electron transfer reactions are discussed.

Effect of cross-linking on matrix permeability. A model for AGE-modified basement membranes

There is much evidence that basement membranes, such as in the renal glomerulus, act as macromolecular sieves, restricting the passage of proteins. Cross-linking of matrix proteins, as occurs because of advanced glycosylation end products (AGEs) in diabetes, may have an effect on the sieving properties of the basement membrane. To test this hypothesis, Matrigel, a basement membrane-like matrix, was cross-linked with glycolaldehyde and control and cross-linked matrices compared. Control matrices allowed less bovine serum albumin to pass through than did cross-linked matrices, with sieving coefficients (SCs) of 0.38 +/- 0.02 and 0.52 +/- 0.02, respectively (P < 0.0005). The control matrices also allowed less cross-linked albumin through than did the cross-linked matrices: 0.13 +/- 0.01 vs. 0.17 +/- 0.02 (P < 0.002). The SCs of a series of fluorescein isothiocyanate dextrans (four sizes, Mr 16,000- 168,000) were lower for the control matrix than for the cross-linked matrix (P < 0.03). In addition, the SC for glycated albumin (incubated with glucose-6-phosphate) was higher than that of normal albumin for both the control (P < 0.04) and cross-linked matrices (P < 0.001). These data indicate that cross-linking of the matrix increases permeability to macromolecules. Analysis of the data using fiber-matrix theory suggests that the mean fiber radius was increased in the cross-linked matrix. The data also indicate that glycated albumin filters through the matrices more easily than does normal albumin. In relation to the situation seen in vivo, it is possible that glycation of circulating proteins and AGE modification of glomerular basement membrane proteins may both contribute to the proteinuria seen in diabetes.

Immunogenicity of a new lot of Francisella tularensis live vaccine strain in human volunteers

A new lot of Francisella tularensis live vaccine strain (LVS) was tested for immunogenicity in 19 human volunteers. Scarification vaccination induced specific cell-mediated and humoral immune responses. We noted a significant rise in antibodies against irradiation-killed LVS, formalin-killed virulent strain SCHU4, and an ether extracted antigen preparation (EEx) beginning 14 days after vaccination. A main target of the humoral immune response was lipopolysaccharide. Eighty percent of vaccinated volunteers developed a positive IgG response to EEx by day 14 and 100% of vaccinees responded positively by day 21. Background IgA titers were lower than corresponding IgG or IgM titers. No early IgM rise was noted with any antigen. By day 14 after vaccination, in vitro lymphocyte responses to LVS, the rough variant of LVS, and EEx were significantly increased compared to controls. Seventy percent of volunteers had a positive in vitro lymphocyte response to EEx within 14 days of vaccination. We predict that EEx will be a useful antigen for diagnosing tularemia and for evaluating the immunogenicity of vaccines against tularemia. We are testing this antigen using sera from human cases of tularemia and control sera.

Protective Effect of Elastase Inhibition Against Myocardial Dysfunction and Injury Induced by Ischemia and Reperfusion in Isolated Rat Hearts

BACKGROUND: Elastase release has been incriminated in the genesis of reperfusion-induced myocardial dysfunction and injury, and elastase inhibitors have been reported to reduce myocardial dysfunction in dogs subjected to coronary artery occlusion and reperfusion. METHODS AND RESULTS: To examine if elastase inhibition will modify myocardial dysfunction and injured induced by ischemia and reperfusion in isolated hearts, hearts from male Sprague Dawley rats were subjected to 30 minutes of total ischemia followed by 30 minutes of reperfusion. Ischemia-reperfusion resulted in myocardial dysfunction (increase in coronary perfusion pressure and decrease in myocardial contraction), injury (measured as creatine kinase release), and lipid peroxidation (myocardial malondialdehyde). Perfusion of hearts with an elastase inhibitor, ICI200,880, protected against myocardial dysfunction, injury and lipid peroxidation following ischemia-reperfusion. As expected, perfusion with superoxide dismutase protected the hearts against hemodynamic deterioration following ischemia-reperfusion. In in vitro studies, there was no direct effect of ICI200,880 on superoxide anion generation. CONCLUSIONS: ICI200,880 seems to exert cardioprotective effects against ischemia-reperfusion-induced injury and myocardial dysfunction in isolated buffer-perfused hearts, most likely by an elastase-like protease inhibitory activity.

Fatal genitourinary mucormycosis in a patient with undiagnosed diabetes

We present what we believe is the first report in the world literature of penile necrosis due to mucormycosis, a rare and often fatal fungal infection. This case of rhizopus mucormycosis began with a penile lesion in a 27-year-old patient with undiagnosed diabetes; it led to necrosis of the phallus, lower urinary tract, rectum, and pelvic musculature and finally to death. Despite repeated aggressive surgical debridement in conjunction with medical therapy, we were unable to halt the progression of the fungal and synergistic bacterial infections.

Efficacy of a spring strategic fenbendazole treatment program to reduce numbers of Ostertagia ostertagi inhibited larvae in beef stocker cattle

Efficacy of a spring strategic treatment program with fenbendazole (FBZ) to reduce the accumulation of Ostertagia ostertagi inhibited early fourth-stage larvae (EL4) was investigated in two groups of crossbred beef heifers which were 7-9 months of age and ranged in weight from 155 to 223 kg. The cattle were allocated to groups and treated on 27 April (Day 0). Group 1 calves served as nontreated controls. Group 2 calves were treated with FBZ 10% drench suspension at 5 mg kg-1 on Day 0 and with 6-day courses of FBZ free-choice mineral (to provide 5 mg kg-1 per animal) on Days 28 and 56. Each group grazed on a separate 4.9 ha pasture for 105 days to 10 August. On 10 August the cattle were taken off pasture and each original group was re-allocated to subgroups of three cattle which were treated orally with FBZ (5 mg kg-1), oxfenbendazole (OXF, 4.5 mg kg-1) or left nontreated (CONT). The cattle were necropsied on Days 120 and 121. Mean actual and cumulative fecal egg counts indicated near total suppression of egg output in the strategically treated group (high of 5.2 eggs g-1 feces (EPG) on Day 28). Egg counts of the nontreated group remained above 100 or 200 EPG to Day 63 and then decreased to less than 100. Ostertagia was the predominant genus, followed by Cooperia on most sampling dates. The largest O. ostertagi worm burdens were recovered from the CONT-CONT subgroup; numbers of EL4 ranged from 18,922 to 51,137. Reduction in numbers of EL4 in original controls, treated with FBZ or OXF in August, were low, being 60.2% and 74.3%, respectively. The numbers of O. ostertagi recovered from subgroups originally treated strategically with FBZ were generally lower than in original controls. The largest reduction in O. ostertagi numbers was in the FBZ-CONT subgroup, which was not treated in August. Percent reduction values for O. ostertagi adults, developing L4 (DL4) and EL4 were 84.6%, 96.7%, and 99.0%, respectively. Percent reduction values for adults, DL4 and EL4 in the FBZ-FBZ and FBZ-OXF subgroups were 90.7%, 61.3%, 85.6% and 92.4%, 45.5%, and 73.0%, respectively. Variability in numbers of EL4 acquired during grazing by original controls and strategically treated cattle and variability in efficacy of August treatments was evident as observed in high outlier numbers of worms in all subgroups except the FBZ-CONT subgroup. Liveweights and gains were nearly identical in the two groups on 10 August.

Persistent anthelmintic activity of ivermectin against gastrointestinal nematodes of cattle

Two experiments were conducted to determine persistence of ivermectin (IVM) anthelmintic activity. In the first experiment, the injectable (INJ) formulation at a dosage of 200 micrograms/kg of body weight and pour-on (PO) formulation at a dosage of 500 micrograms/kg were compared in 5 groups of calves (n = 6/group). Calves were treated at 14 and 7 days prior to experimentally induced infection. Experimental groups were: 1--untreated, infected controls; 2--IVM PO, day -14; 3--IVM PO, day -7; 4--IVM INJ, day -14; and 5--IVM INJ, day -7. Calves were necropsied on days 28 and 29 after infection. Results of this experiment indicated a high degree of efficacy of IVM PO product (93.8%) for all nematodes up to 14 days, in contrast to poor activity for IVM INJ (26.3%) for all nematodes. Seven-day persistence was excellent for both IVM formulations against Ostertagia ostertagi and Cooperia spp, but a lower degree of efficacy (77.0% for PO and 88.5% for INJ) was observed against Haemonchus placei. In the second experiment, persistent efficacy of IVM PO in preventing establishment of O ostertagi inhibited larvae was observed. In 3 trials, groups of 4 treated and 4 untreated control calves were exposed to natural pasture infection at 0 to 7, 10 to 17, and 20 to 27 days after treatment. Calves were necropsied 15 to 16 days after removal from pasture. After the day 0 to day 7 infection exposure, IVM PO efficacy was 100% for all stages of O ostertagi, 3 adult male Cooperia spp, and Oesophagostomum radiatum; 94.9% for H placei; and 98.2% for Cooperia spp adult females.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the non-specific humoral and cellular antiviral immunity stimulated by the chloroform-methanol residue (CMR) fraction of Coxiella burnetii

Modulation of the immune response by the chloroform-methanol residue (CMR) of phase I Coxiella burnetii whole cell was studied in Rift Valley fever virus-infected, or in naive endotoxin-non-responder C3H/HeJ mice. A single dose of CMR completely protected the mice from viral infection. Treating virus-infected mice with antibodies directed against interferons alpha/beta (IFN-alpha beta) and gamma (IFN-gamma) eliminated the CMR-induced protection. CMR stimulated the production of high levels of IFN-alpha/beta and 2'-5'-oligoadenylate synthetase activities in sera of the CMR-treated mice. IFN-gamma was present in supernatants of cultured spleen cells of CMR-treated, virus-infected mice, but not in their serum. Priming mice with CMR optimized the release of INF-gamma, interleukin-1 alpha (IL-1 alpha) and IL-6 from splenocytes in vitro. When stimulated in vitro, IL-2 and granulocyte-macrophage stimulating factor (GM-CSF) did not require in vivo priming for release from cultured spleen cells. Fluorescence-assisted cytometry of CMR-treated mouse spleen cells showed there was a CMR-dependent increase in the percentage of T-cells and Ia-positive T-cells. There also was a biphasic increase in the ratio between Th (L3T4) and Ts (Lyt2) cells. Biological activities stimulated by CMR indicate that CMR is a potent immunostimulant, which may modulate specific and non-specific antiviral responses.