Active immunization with tau epitope in a mouse model of tauopathy induced strong antibody response together with improvement in short memory and pSer396-tau pathology.

Abnormal tau hyperphosphorylation and its aggregation into neurofibrillary tangles are a hallmark of tauopathies, neurodegenerative disorders that include Alzheimer's disease (AD). Active and passive Tau-immunotherapy has been proposed as a therapeutic approach to AD with mixed results. One of the limitations of active immunotherapy may be associated with the mediocre immunogenicity of vaccines that are not inducing therapeutically potent titers of antibodies. The aim of this study was to test the efficacy of an anti-tau vaccine, AV-1980R/A composed of N terminal peptide of this molecule fused with an immunogenic MultiTEP platform and formulated in a strong adjuvant, AdvaxCpG in a Tg4510 mouse model of tauopathy. Experimental mice were immunized with AV-1980R/A and a control group of mice were injected with adjuvant only. Nontransgenic and tetracycline transactivator (tTA) transgenic littermates were included as baseline controls to contrast with the tau phenotype. Active immunization with AV-1980R/A induced very strong anti-tau humoral immune responses in both nontransgenic and transgenic mice with evidence of IgG in brains of AV-1980R/A vaccinated mice. These experimental animals displayed an improvement in short-term memory during a novel object recognition test. However, impairments in other behavioral tasks were not prevented by AV-1980R/A vaccinations. At the same time, high titers of anti-tau antibodies reduced hyperphosphorylated pSer396 tau but did not lower the level of other phosphorylated tau species in the brains of AV-1980R/A vaccinated mice. These data indicate that active immunotherapy with an N-terminal Tau epitope was only partially effective in improving cognition and reducing pathology in the stringent Tg4510 mouse model of tauopathy.

Maternal diet but not gestational weight gain predicts central adiposity accretion in utero among pregnant adolescents.

BACKGROUND: Modifiable risk factors during pregnancy, such as diet and weight gain, are associated with fetal birth weight but little is known about how these factors influence fetal fat acquisition in utero among pregnant adolescents. OBJECTIVE: To determine whether maternal pre-pregnancy BMI (ppBMI), gestational weight gain (GWG) and dietary intake during pregnancy influence fetal fat accretion in utero. METHODS: Longitudinal data were obtained from 121 pregnant adolescents enrolled in a study designed to identify determinants of maternal and fetal bone changes across gestation. Adolescents (ages 13-18 years) completed up to three study visits during early, mid- and late gestation. Maternal anthropometrics, 24 h dietary recalls and measures of fetal biometry were obtained at each visit. Fetal abdominal wall thickness (abdominal subcutaneous fat thickness, AbFat), a measure of fetal subcutaneous fat, was calculated by sonography at each visit. Statistical determinants of AbFat during late pregnancy were explored using simple and multiple regression. RESULTS: During late pregnancy (34.8±2.0 weeks; range 31.0-40.6 weeks of gestation), the median (inter-quartile range) fetal AbFat and GWG were 0.44 (0.39, 0.55) cm and 14.6 (9.5, 18.3) kg, respectively. After adjusting for infant birth weight, variables significantly associated with fetal AbFat included gestational age (P<0.0001, 95% confidence interval, CI: 0.01, 0.03), maternal race (P=0.029, 95% CI: -0.04, -0.002) and dietary intake of added sugar (P=0.025, 95% CI: 1.42e-6, 2.06e-5). Fetal AbFat had a significant positive quadratic relationship with total maternal dietary sugar intake such that both low and high extremes of sugar consumption were associated with significantly higher fetal AbFat. Birth weight was not significantly associated with maternal intake of added sugars. CONCLUSION: Extreme sugar intakes among pregnant adolescents may lead to increased accumulation of fetal abdominal fat with little net effect on birth weight. This finding suggests that increased sugar consumption during pregnancy promotes shifts in fetal body composition.

Safety of labor, Valsalva maneuver, and neuraxial anesthesia for pregnant women after decompressive craniectomy: Case series and review of the literature.

Decompressive craniectomies are a neurosurgical operation aimed at normalizing intracranial pressure (ICP). Occasionally, there is delayed replacement of the skull resulting in an acquired skull defect. When managing laboring patients with an acquired skull defect there is often fear associated with traditional labor involving the Valsalva maneuver and with neuraxial anesthesia. These fears typically stem from potential ICP changes and risk of herniation. In reviewing the literature, only 15 cases are described detailing labor management after decompressive craniectomy (DC), mostly with incomplete labor histories. We aim to expand that literature by reporting two cases of safe labor with epidural anesthesia in patients with large skull defects. The first described patient underwent a cranioplasty during pregnancy because of trauma. Later, because of concerns for pre-eclampsia, induction of labor was initiated and she received neuraxial anesthesia via epidural. The patient ultimately underwent cesarean delivery 48 h after induction began due to nonreassuring fetal heart tones. The second patient underwent a cranioplasty because of infection prior to pregnancy. Once in labor, she was cleared by neurosurgery and the anesthesia team placed her epidural. She later underwent an uncomplicated standard vaginal delivery. The existing literature on labor following DC is sparse. Retrospective review of case reports can advance discussion and standardization regarding care for laboring women with a history of DC. We advocate that the Valsalva maneuver and epidural anesthesia is safe for pregnant women who are neurologically asymptomatic.

Fetal anatomic evaluation in the overweight and obese gravida.

OBJECTIVES: To evaluate the rate of completion of anatomic surveys of fetuses in overweight and obese gravid patients as compared with normal controls. METHODS: This was a retrospective review of anatomic ultrasound scans performed between 2004 and 2007. Women were stratified by prepregnancy body mass index (BMI) into normal weight (BMI, 18.5-24.9 kg/m(2)), overweight (BMI, 25.0-29.9 kg/m(2)) and obese Class I (BMI, 30.0-34.9 kg/m(2)), Class II (BMI, 35.0-39.9 kg/m(2)) and Class III (BMI >or= 40.0 kg/m(2)) groups. Rates of completion of basic and comprehensive scans, gestational age at completion and number of scans required were compared. RESULTS: For the 7140 patients included, completion rates for both the basic (normal weight, n = 2253 (79%); overweight, n = 1771 (76%); obese Class I, n = 767 (72%), Class II, n = 323 (61%) and Class III, n = 171 (49%)) and comprehensive (normal weight, n = 1234 (43%); overweight, n = 930 (40%); obese Class I, n = 404 (38%), Class II, n = 215 (41%) and Class III, n = 108 (31%)) surveys decreased significantly with increasing BMI (P < 0.00001). For surveys completed, the mean number of scans required was significantly higher for obese patients (basic: normal weight 1.3 vs. obese Class III 1.9; comprehensive: normal weight 1.7 vs. obese Class III, 2.2)(P < 0.00001). The overall completion rate improved at each gestational week, but was best between 20 and 23 weeks for obese patients. CONCLUSIONS: As maternal BMI increases, the rate of completion of anatomic surveys decreases and the number of scans required increases. Delaying the initial survey until 20 weeks' gestation may improve the capacity to complete the examination in a single visit. It should be noted that these results represent completion rates at a tertiary referral center, and therefore may not reflect community experience.

Fetal nuchal translucency thickness evaluation in the overweight and obese gravida.

OBJECTIVE: To evaluate the time required and failure rate for completion of nuchal translucency thickness (NT) measurements with increased maternal body mass index (BMI). METHODS: This was a retrospective review of ultrasound examinations for NT measurement in 11-14-week singleton pregnancies performed at a single site from 2004 to 2007. Women were stratified by prepregnancy BMI into normal weight (BMI, 18.5-24.9 kg/m(2)), overweight (BMI, 25.0-29.9 kg/m(2)) and obese Class I (BMI, 30.0-34.9 kg/m(2)), Class II (BMI, 35.0-39.9 kg/m(2)) and Class III (BMI >or= 40.0 kg/m(2)) groups. The failure rate, the time required for measurement, and the total study time in min were evaluated by BMI class for the first attempt and for all attempts at NT measurement. RESULTS: A total of 2508 women underwent attempted NT screening with complete data available on 1678 women (1707 examinations). The failure rate for NT screening varied significantly according to BMI (P < 0.001). At the first attempt, the median time for NT measurement varied significantly according to BMI (normal weight group, 9.7 (interquartile range (IQR) 4.4, 19.0) min; overweight group, 8.8 (4.0, 19.8) min; obese Class I, 9.6 (4.8, 20.4) min; Class II, 14.1 (5.0, 28.2) min; Class III, 12.3 (4.6, 22.7) min; P < 0.01), as did the total study time (normal group, 16.4 (10.1, 26.6) min; overweight group, 15.7 (9.8, 25.0) min, Class I, 17.3 (10.3, 29.2) min; Class II, 23.0 (12.2, 36.1) min; Class III, 18.7 (11.0, 30.8) min; P = 0.002). For all attempts also, the median time for NT measurement varied significantly according to BMI (normal weight group, 9.7 (IQR 4.4, 19.0) min; overweight group, 8.8 (4.0, 19.9) min; obese Class I, 9.6 (4.8, 21.0) min; Class II, 14.1 (5.0, 28.7) min; Class III, 12.3 (4.6, 22.5) min; P < 0.01), as did the total study time (normal weight group, 16.4 (10.2, 26.7) min; overweight group, 15.7 (9.8, 25.1) min; Class I, 17.6 (10.4, 29.9) min; Class II, 23.2 (12.0, 37.5) min; Class III, 18.7 (11.9, 31.9) min; P < 0.001). CONCLUSION: As maternal BMI increases, the time required to obtain NT measurements and the failure rate increase. Before the ultrasound examination, patients with a BMI over 30 should be counseled regarding the need for additional time and failure rates for first-trimester screening.

Sonographic birth-weight prediction in obese patients using the gestation-adjusted prediction method.

OBJECTIVES: Ultrasound birth-weight prediction may be more accurate if assessed at 34 to 36 + 6 weeks' gestation and extrapolated using the gestation-adjusted projection (GAP) method than if done at term. Because ultrasound is less accurate in women with elevated body mass index (BMI), we assessed the accuracy of GAP birth-weight prediction in obese as compared to non-obese women. METHODS: We performed a retrospective review of 1382 women with singleton pregnancies who had undergone fetal ultrasound examination at between 34 + 0 and 36 + 6 weeks, subclassified by pre-pregnancy BMI. Analysis of variance was used to compare predicted and actual birth weight. RESULTS: 1025 controls and 357 obese women were included. The obese women were divided by BMI: 159 in Class I (BMI, 30-34.9 kg/m(2)); 105 in Class II (BMI, 35-40 kg/m(2)) and 93 in Class III (BMI > 40 kg/m(2)). Mean systematic (percent) birth-weight prediction error was within 4% for all groups, with a 95% error range between - 5% and + 5%. The GAP method was able to predict actual birth weight within 20% for all groups in over 90% of cases. For all groups, the GAP method correctly excluded the presence of macrosomia with >or= 90% specificity. Negative likelihood ratios for the prediction of macrosomia were between 0.4 and 0.6 for all groups, regardless of obesity. CONCLUSIONS: The GAP method of birth-weight prediction using ultrasound measurement at 34 to 36 + 6 weeks predicts birth weight within 20% error in over 90% of cases, and is able to exclude macrosomia with over 90% accuracy regardless of maternal BMI.

Human red cell Aquaporin CHIP. II. Expression during normal fetal development and in a novel form of congenital dyserythropoietic anemia.

Channel-forming integral protein (CHIP) is the archetypal member of the Aquaporin family of water channels. Delayed CHIP expression was shown recently in perinatal rat (Smith, B. L., R. Baumgarten, S. Nielsen, D. Raben, M. L. Zeidel, and P. Agre. 1993. J. Clin. Invest. 92:2035-2041); here we delineate the human patterns. Compared with adult, second and third trimester human fetal red cells had lower CHIP/spectrin ratios (0.72 +/- 0.12, 0.94 +/- 0.22 vs 1.18 +/- 0.11) and reduced osmotic water permeability (0.029, 0.026 vs 0.037 cm/s); CHIP was already present in human renal tubules by the second trimester. A patient with a novel form of congenital dyserythropoietic anemia (CDA) with persistent embryonic and fetal globins and absent red cell CD44 protein was studied because of reduced CHIP-associated Colton antigens. Novel CDA red cells contained < 10% of the normal level of CHIP and had remarkably low osmotic water permeability (< 0.01 cm/s), but no mutation was identified in Aquaporin-1, the gene encoding CHIP. These studies demonstrate: (a) unlike rat, human CHIP expression occurs early in fetal development; (b) red cell water channels are greatly reduced in a rare phenotype; and (c) disrupted expression of red cell CHIP and CD44 suggests an approach to the molecular defect in a novel form of CDA.

Adsorption of non-membrane proteins on the surface of model phospholipid membranes.

1. Two new methods are proposed for enhancement of the binding of hydrophilic proteins by liposomes. 2. An alkylating derivative of phosphatidic acid has been obtained by its reaction with N,N,N'-tris(2-chloroethyl)-N'-(p-formylphenyl)propylene-1,3-diamine. The alkylating activity of this derivative is very low due to the electron-acceptor effect of the formyl residue. Phosphatidylcholine liposomes which contain this alkylating derivative in the lipid bilayer may be obtained. The compound residing in the outer monolayer may be reduced by NaBH4. Upon reduction, the formyl residue is transformed into a hydroxymethyl residue. Therefore, the alkylating group of the compound is activated, and proteins may be attached covalently to the outer monolayer by alkylation with such chemically reactive liposomes. 3. Reaction of alkylating liposomes with myoglobin results in covalent binding of this hydrophilic protein. Complement-mediated leakage of such myoglobin-carrying liposomes may be induced by antibodies against myoglobin. 4. Modification of hydrophilic proteins with dansyl chloride results, even at small extents of modification, in a dramatic increase of the affinity of such proteins to phosphatidylcholine liposomes.

Whole mount immunofluorescence analysis of placentas from normotensive versus preeclamptic pregnancies.

INTRODUCTION: Defects in placental angiogenesis and spiral artery remodeling have been proposed to play essential roles in the development of preeclampsia. However, the specific molecular mechanism(s) responsible for aberrant placental angiogenesis in preeclampsia are incompletely understood. The vascular endothelial growth factor receptors (VEGFR1, R2, R3) and STAT3 have critical functions in normal blood vessel development, but their potential roles in preeclampsia are currently unclear. In this study, we utilized a novel whole mount immunofluorescence (WMIF) method to compare expression of VEGFR1, R2, R3 and activated, phosphorylated STAT3 (pSTAT3) in placentas of preeclamptic (PE) versus normotensive (NT) pregnancies. METHODS: Placental biopsies collected from NT and PE pregnant women were fixed and stained with fluorochrome-conjugated antibodies to identify specific cell populations as follows: CD31 for blood vessel endothelial cells, cytokeratin-7 for trophoblast cells, and CD45 for immune cells. Expression of the VEGFRs and pSTAT3 were subsequently characterized by WMIF in conjunction with confocal microscopy. RESULTS: A total of 18 PE and 18 NT placentas were evaluated. No significant differences in the cell type-specific expression patterns or expression levels of VEGFR1, VEGFR2 or VEGFR3 were detected between NT and PE placentas. In contrast, statistically significant increases in pSTAT3 staining were detected in endothelial cells of PE placentas versus NT controls. DISCUSSION: Our study demonstrates that increased pSTAT3 expression in placental endothelial cells is associated with PE. We speculate that elevated pSTAT3 expression in the blood vessels of PE placentas may be due to aberrant angiogenesis, increased pro-inflammatory cytokine expression, and/or placental stress.

Heterocomplexes of tick-borne encephalitis structural and non-structural proteins.

The existence of the complex of structural and non-structural proteins in the tick-borne encephalitis (TBE) virus is shown. The complex was isolated from virus-containing cultural medium by immunoaffinity chromatography on monoclonal antibodies (MAbs). By enzyme immunoassay and immunoblotting with the use of appropriate MAbs it was demonstrated that this complex consists of structural (protein E), and non-structural (NS1) glycoproteins. Also, the trimer E-NS1-NS3 can be isolated. It is proposed that this trimer is the viral replicative complex.

A new system for ATP-metric immunoanalysis.

Treatment of amino-group-containing antigens with adenosine-5'-trimetaphosphate results in their chemical modification by -pppA residues. An immunoanalytical system is proposed based upon competition of these ATP-labelled antigens with those of the sample for immobilized antibodies. Mild acidic treatment of complexes of ATP-labelled antigens with immobilized antibodies results in quantitative liberation of intact ATP. The latter may be determined by the ultrosenstive bioluminescent techniques based upon emission of light with firefly luciferase. The validity of the system has been studied with two clinically important antigens, thyroxine and myoglobin.

Variabilities in the antigenic structure of persisting tick-borne encephalitis virus strains.

Antigenic variants in the E protein from persisting tick-borne encephalitis (TBE) virus strains were analyzed using monoclonal antibodies (MAbs) to an analogous protein of the reference Sofyin strain. MAbs to sequential epitopes demonstrated their ability to differentiate persisting TBE virus strains from Sofyin and from each other. Two MAbs (2H3 and 13D6) showed a higher neutralizing activity in the interaction with persisting TBE virus variants as compared to the Sofyin strain. Based on the obtained data, a comparison was made of topologically identical epitopes from the E protein of reference and persisting virus strains. The possibility of increasing the neutralizing activity of MAbs through alterations in the primary structure of sequential antigenic sites is discussed.

Epitope analysis of tick-borne encephalitis (TBE) complex viruses using monoclonal antibodies to envelope glycoprotein of TBE virus (persulcatus subtype).

The arrangement of envelope protein epitopes of tick-borne encephalitis viruses (TBEV) (persulcatus or eastern subtype, Sofjin strain and ricinus or western subtype, Minsk-256 strain) and Kyasanur Forest disease virus (KFDV) was investigated using competitive binding of monoclonal antibodies against the Sofjin E protein. The E protein of TBEV Sofjin strain forms three antigenic domains: E1, E2 and E3, represented by 12, 9 and 2 epitopes respectively; two additional epitopes stand alone. Domains E1 and E2 are heterogeneous. On the epitope map of the Minsk-256 strain domain E3 remains intact, domains E1 and E2 overlap and the relative arrangement of virus-neutralizing epitopes from E1 and E2 domains is changed. The epitope map of KFDV is significantly dissimilar to TBEV. The viruses can be distinguished by epitopes with identical serological reactivity. A satisfactory agreement between our epitope maps and previously published antigenic models of flavivirus envelope protein (Guirakhoo et al., 1989; Mandl et al., 1989a) was observed. The main difference of our map is that domains corresponding to domains B and C (Sofjin strain) and A, B and C (Minsk-256 strain) in Heinz's model are overlapping. The results of competition analysis depend on the nature of the antigen (virion or purified protein) and the immunoassay technique.

Comparative analysis of serological activity of non-structural protein (NS1) from tick-borne encephalitis virus and its analog expressed in bacterial cells.

By means of immunoaffinity chromatography and expression of the gene in Escherichia coli, non-structural glycoprotein NS1 of tick-borne encephalitis virus (TBEV) and its recombinant analog were prepared. Antisera against these proteins were obtained by hyperimmunisation of rabbits. The antisera were tested by means of complement fixation, agar diffusion, hemagglutination inhibition and virus neutralization. Although both antisera are reacted with natural antigen, the recombinant analog of NS1 did not bind antibodies against natural protein in complement fixation and immunoprecipitation. Nevertheless the NS1 analog was rather active in ELISA. Neither the natural nor the recombinant protein protected experimental animals from lethal virus infection. A contamination of natural NS1 antigen with small amounts of structural glycoprotein E may be responsible for both antibody formation and virus neutralization. This can be relevant for the design of a subunit vaccine.

A paternally derived inverted duplication of 7q with evidence of a telomeric deletion.

We report on a de novo constitutional rearrangement involving the long arm of chromosome 7 in a second trimester fetus with the karyotype of 46,XX, inv dup del (7)(pter-q36::q36-q21.2:) pat. Both a large duplication (q21.2-q36) and a small deletion (within q36) were confirmed by FISH studies. DNA analysis on the family showed that the abnormal chromosome was derived from a single paternal homolog. A mechanism is proposed in light of this finding. The phenotype at autopsy was consistent with reported cases of similar duplications in chromosome 7 in that hydrocephalus, a depressed nasal bridge, low set ears, microretrognathia and a short neck were present.

Prediction of birth weight by ultrasound in the third trimester.

OBJECTIVE: To compare the accuracy of predicted birth weight by the gestation-adjusted projection method using ultrasonographic measurements obtained just before and at term. METHODS: The study group comprised patients with singleton pregnancies who underwent sonograms between 34.0 and 36.9 weeks' gestation (period 1) and at 37 weeks and beyond (period 2). The mean error in birth weight prediction, absolute birth weight error, and signed and absolute percent errors were compared with paired t tests. Thus, each patient served as her own control. RESULTS: The study included 138 patients undergoing 276 sonograms. The mean absolute error of the predicted birth weight was smaller for period 1 than for period 2 (197 +/- 167 g compared with 235 +/- 209 g, P =.019). The mean absolute percent error was 6.2 +/- 5.2% for period 1 compared with 7.4 +/- 6.3% for period 2 (P =.019). These same trends were observed when fetuses with suspected growth abnormalities were examined separately. Averaging data from both gestational periods did not improve the prediction of birth weight. CONCLUSION: Sonograms between 34.0 and 36. 9 weeks' gestation allow for more accurate prediction of birth weight than sonograms later in gestation. Though these differences are small and not clinically significant, this study indicates that serial sonograms in the late third trimester do not improve the ability to predict birth weight, even in abnormally grown fetuses. A single sonogram between 34 and 37 weeks' gestation is recommended for prediction of birth weight.

Consent documents, reproductive issues, and the inclusion of women in clinical trials.

PURPOSE: To describe language used in consent documents at one academic medical center to inform women participating in studies of potential reproductive and fetal risks. METHOD: The authors reviewed consent document language describing reproductive and fetal risks in 114 approved protocols. Protocols were identified as being of high, low, or unknown risk based upon FDA drug-risk and radiation-risk categories. RESULTS: Although most consent documents advised women against participating for one or more pregnancy-related reasons, specific information about reproductive or fetal risks was included in fewer consent documents: 8 (73%) of the high-risk studies, 12 (40%) of the low-to-moderate-risk studies, and 29 (40%) of the unknown-risk studies. CONCLUSIONS: Investigators often omit fetal risk information from consent documents. Full disclosure of reproductive and fetal risks in consent documents and discussions can be taught and modeled during the research training period. The authors present a template with language that can be used in consent documents and recommend ongoing discussion of reproductive and fetal risks with women subjects throughout the study period.

Chronic cerebellar stimulation in cerebral palsy.

This report summarizes the experience with chronic cerebellar stimulation in cerebral palsy patients at the Children's Hospital of Eastern Ontario. From July, 1977, to September, 1978, 12 patients suffering from cerebral palsy underwent cerebellar implant for chronic cerebellar stimulation. Postoperative evaluation was made approximately 1 week, 3 months, 6 months, and 12 months after surgery by a group of specialists using speech, respiration, muscle tone, involuntary movements, salivation, and activities of daily living as parameters, and these findings were compared with the findings prior to surgery. Chronic cerebellar stimulation did not noticeably alleviate symptoms and signs of cerebral palsy nor did it improve activities of daily living in a significant number of patients.

Differentiating lymphocytic adenohypophysitis from pituitary adenoma in the peripartum patient.

Lymphocytic adenohypophysitis (LAH) is an autoimmune disorder of the pituitary gland with a predilection for the peripartum period and often mimics a pituitary adenoma. We sought to define the clinical, endocrinologic and radiographic characteristics differentiating peripartum LAH from pituitary adenoma to enable the use of noninvasive diagnosis and appropriate therapy. From published reports and our own case, the clinical histories and laboratory and radiographic studies of 45 patients fulfilling the diagnosis of peripartum LAH were reviewed. History of infertility or menstrual irregularity, symptomatology, endocrinologic evaluation, diagnostic imaging and associated medical conditions were analyzed. For comparison, 806 patients with pituitary adenoma and pregnancy from published series were evaluated. The spontaneous pregnancy rate in pituitary adenoma patients was 2.4% vs. 100% in LAH patients. Visual disturbances and headaches were significantly more frequent in patients with LAH. Prolactin levels were significantly lower in patients with LAH than in those with pituitary adenomas (34.6 +/- 46.3 [SD] vs. 393.0 +/- 300.4, P < .0001). Abnormalities in thyroid and/or adrenal function were also more common in patients with LAH (57.5% vs. 2.5%, P < .001). There were no distinguishing characteristics on radiographic studies. History and endocrinologic evaluation can differentiate between LAH and pituitary adenoma in the peripartum patient.

Effects of lasalocid or monensin on legume or grain (feedlot) bloat.

Doses of .66 to .99 mg monensin/kg body weight reduced legume bloat in cattle about 66% when compared with pretreatment bloat scores. Similar doses of lasalocid reduced legume bloat about 26%. A dose of 44 mg poloxalene/kg body weight (recommended dose for field use) reduced legume bloat 100%. Monensin or lasalocid combined with 25 or 50% of the recommended dose of poloxalene reduced bloat under that of the antibiotics alone, but did not achieve 100% reduction. The antibiotic thiopeptin provided no preventive effect on legume bloat. Lasalocid, monensin or an experimental polyether antibiotic (X-14,547 A) at a dose of 1.32 mg/kg body weight when tested on cattle bloated on high grain diets reduced bloat by 92, 64 and 25%, respectively. Lasalocid at .66 mg/kg effectively prevented bloat from developing when given to animals before the feeding of high grain diets; however, a 1.32-mg dose was required to control bloat in cattle that were already bloating before they were given lasalocid. A dose of 1.32 mg salinomycin was ineffective in controlling grain bloat.