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Dendritic cells (DCs) are at the interface of innate and adaptive immune responses. Once activated via triggering of their pattern recognition receptors (PRRs), they acquire a mature state and migrate to the lymph nodes where they activate T cells and direct the immune response. Compounds that trigger PRRs are potential vaccine adjuvants, hence in this study we stimulated two porcine DC populations, namely monocyte-derived DCs (MoDCs) and blood DCs (BDCs), with a broad range of toll-like receptors (TLRs) ligands and assessed the activation/maturation state of these porcine DCs. In order to determine if TLR ligands would have an effect on porcine DCs, we characterized the expression of TLRs and demonstrated that MoDCs and BDCs expressed the same set of TLRs but at different levels. Of the TLR ligands examined, lipopolysaccharide (LPS) and poly I:C were the most potent activators of MoDCs, inducing the up-regulation of co-stimulatory molecules CD80/86 and the chemokine receptor CCR7, and production of pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)alpha. The most effective in inducing BDCs activation were LPS and class A CpG oligodeoxynucleotide (ODN), resulting in up-regulation of chemokine receptor (CCR)7 and down-regulation of CCR2 and CCR5, production of IL-12p40, and expression of a broad range of chemokines that were able to attract porcine immune cells., ((c) 2010 Elsevier Ltd. All rights reserved.)

Various dendritic cell (DC) populations exist that differ in phenotype and ability to present antigen to T cells. For example, plasmacytoid DCs (pDCs) are less potent T cell activators compared with conventional DCs (cDCs). Here, we compared porcine blood DCs (BDCs), containing pDCs and cDCs, and monocyte-derived DCs (MoDC), consisting of cDCs, in their phenotype, ability to uptake antigen, activation and maturation and their ability to present antigen to autologous T cells. Pigs represent an important animal model, whose immune system in many respects closely resembles that of humans. For example, the distribution of Toll-like receptors is similar to that of humans, in contrast to that of mice. Here we demonstrate that both populations endocytose foreign material. Following lipopolysaccharide stimulation, CD80/86 and chemokine receptor (CCR)7 expression was increased in both populations as was the expression of the chemokine ligands (CCL)-2, CCL-4, CCL-20 and CXCL-2. Although basal and post-stimulation protein concentrations of interleukins 6 and 8 and tumour necrosis factor-alpha were higher in MoDCs, protein concentrations showed a higher fold increase in BDCs. Antigen-specific proliferation of autologous T cells was induced by MoDCs and BDCs. Interestingly, while MoDCs induced stronger proliferation in naive T cells, no difference in proliferation was observed when primed T cells were studied. These results demonstrate that isolated porcine BDCs are highly responsive to stimulation with lipopolysaccharide and are functionally able to drive primed T-cell proliferation to the same extent as MoDCs.

The purpose of this study was to identify loci associated with Mycobacterium avium subspecies paratuberculosis (Map) infection status in US Holsteins using the Illumina BovineSNP50 BeadChip whole genome single nucleotide polymorphism (SNP) assay. Two hundred forty-five cows from dairies in New York, Pennsylvania and Vermont enrolled in longitudinal herd studies between January 1999 and November 2007 were assessed for the presence of Map in both faecal and tissue samples. An animal was considered tissue infected if any sample contained at least one colony forming unit of Map per gram of tissue (CFU/g) and the same definition was employed for faecal samples. Each animal was genotyped with the Illumina BovineSNP50 BeadChip and after quality assurance filtering, 218 animals and 45 683 SNPs remained. We sought to identify loci associated with four different case/control classifications: presence of Map in the tissue, presence of Map in faeces, presence of Map in both tissue and faeces and presence of Map in tissue but not faeces. A case-control genome wide association study was conducted to test the four different classifications of Map infection status (cases) when compared with a Map-negative control group (control). Regions on chromosomes 1, 5, 7, 8, 16, 21 and 23 were identified with moderate significance (P < 5 x 10(-5)). Two regions, one on chromosome 3 (near EDN2) and another on chromosome 9 (no positional gene candidates), were identified with a high level of association to the presence of Map in tissue and both tissue and faeces respectively (P < 5 x 10(-7), genome-wide Bonferonni P < 0.05).

Endemic infectious diseases in dairy cattle are of significant concern to the industry as well as for public health because of their potential impact on animal and human health, milk and meat production, food safety, and economics. We sought to provide insight into the dynamics of important endemic infectious diseases in 3 northeastern US dairy herds. Fecal samples from individual cows and various environmental samples from these farms were tested for the presence of major zoonotic pathogens (i.e., Salmonella, Campylobacter, and Listeria) as well as commensal bacteria Escherichia coli and enterococci. Additionally, the presence of Mycobacterium avium ssp. paratuberculosis was tested in fecal and serum samples from individual cows. Test results and health and reproductive records were maintained in a database, and fecal, plasma, DNA, and tissue samples were kept in a biobank. All bacteria of interest were detected on these farms and their presence was variable both within and between farms. The prevalence of Listeria spp. and L. monocytogenes in individual fecal samples within farm A ranged from 0 to 68.2% and 0 to 25.5%, respectively, over a period of 3 yr. Within farm B, continuous fecal shedding of Salmonella spp. was observed with a prevalence ranging from 8 to 88%; Salmonella Cerro was the predominant serotype. Farm C appeared less contaminated with Salmonella and Listeria, although in the summer of 2005, 50 and 19.2% of fecal samples were positive for Listeria and L. monocytogenes, respectively. The high prevalence of E. coli (89 to 100%), Enterococcus (75 to 100%), and Campylobacter (0 to 81%) in feces suggested they were ubiquitous throughout the farm environment. Fecal culture and ELISA results indicated a low prevalence of Mycobacterium avium ssp. paratuberculosis infection in these farms (0 to 13.6% and 0 to 4.9% for culture-positive and ELISA-positive, respectively), although the occasional presence of high shedders was observed. Results have major implications for food safety and epidemiology by providing a better understanding of infectious disease dynamics on dairy farms. Comprehensive understanding of these infections may lead to better farm management practices and pathogen reduction programs to control and reduce the on-farm contamination of these pathogens and to prevent their further entry into the food-chain.

The objective of the study was to screen a large number of herd management practices and herd characteristics from US dairies to identify herd-level risk factors associated with the presence of Listeria monocytogenes in bulk tank milk (BTM). A total of 71 variables was univariately evaluated for their association with the presence of L. monocytogenes in BTM. Results from the univariate analysis indicated that using automatic take offs and having an open herd management increased the risk of BTM contamination with L. monocytogenes, while storing manure in outside pens not accessible to cattle decreased the risk. These variables, however, were not sustained in the multivariable model, which indicated that the presence of L. monocytogenes in BTM was significantly associated with region of the country (farms in the southeast and northeast were six and four times more likely respectively, to have BTM contamination than farms in the west) and number of milking cows (herds with >500 milking cows were five times more likely to have BTM contamination than herds with <100 milking cows). In conclusion, our results suggest that risk factors associated with BTM contamination are different depending on the geographical region and herd size of the operation.

Although dairy cattle are known reservoirs for salmonellae, cattle that are shedding this organism are often asymptomatic and difficult to identify. A dairy herd that was experiencing a sustained, subclinical outbreak of Salmonella enterica subsp. enterica Cerro was monitored for 2 years. Fecal samples from the lactating cows were collected every 6 to 8 weeks and tested for the presence of Salmonella. Fecal prevalence of Salmonella fluctuated throughout the observation period and ranged from 8 to 88%. Manure composites and water trough samples were collected along with the fecal samples, and bulk milk and milk filters were cultured for the presence of Salmonella on a weekly basis. Over 90% of the manure composites--representing high-animal-traffic areas-were positive at each sampling. Salmonella was detected in 11% of milk samples and in 66% of the milk filters. Results of weekly bulk milk quality testing (i.e., bulk tank somatic cell score, standard plate count, preliminary incubation count) were typically well within acceptable ranges. Milk quality variables had low correlations with herd Salmonella fecal prevalence. When observed over time, sampling period average prevalence of Salmonella in milk filters closely paralleled fecal prevalence of Salmonella in the herd. Based on results of this study, milk filters appear to be an effective method for monitoring shedding prevalence at the herd level. In-line filter testing is also a more sensitive measure of Salmonella, and perhaps other pathogens, in raw milk than testing the milk alone.

Johne's disease is caused by Mycobacterium avium subsp. paratuberculosis (MAP) infection and results in economic losses in the dairy industry. To control MAP transmission in herds, test-based culling has been recommended and immediate culling of high shedding animals is typically implemented. In this study, we quantified the effects of MAP control in US dairy herds, using the basic reproduction ratio R(0). The effectiveness of culling strategies was evaluated for good and poor herd management (low- and high-transmission rates, respectively) by a phase diagram approach. To establish a quantitative relationship between culling rates and test properties, we defined the average detection times for low and high shedding animals. The effects of various culling strategies and test characteristics, such as test sensitivity, test turnaround time, and testing interval, were analyzed. To understand the overall effect of model parameters on R(0), we performed global uncertainty and sensitivity analyses. We also evaluated the effectiveness of culling only high shedding animals by comparing three test methods (fecal culture, fecal polymerase chain reaction, PCR, and enzyme-linked immunosorbent assay, ELISA). Our study shows that, in the case of good herd management, culling of only high shedding animals may be effective in controlling MAP transmission. However, in the case of poor management, in addition to immediate culling of high shedding animals, culling of low shedding animals (based on the fecal culture test) will be necessary. Culling of low shedding animals may be delayed 6-12 months, however, if a shorter testing interval is applied. This study suggests that if farmers prefer culling only high shedding animals, faster MAP detection tests (such as the fecal PCR and ELISA) of higher sensitivity should be applied with high testing frequency, particularly on farms with poor management. Culling of infectious animals with a longer testing interval is generally not effective to control MAP.

We developed a mathematical model of the transmission dynamics of salmonella to describe an outbreak of S. Cerro infection that occurred in a Pennsylvania dairy herd. The data were collected as part of a cooperative research project between the Regional Dairy Quality Management Alliance and the Agricultural Research Service. After the initial detection of a high prevalence of S. Cerro infection in the herd, a frequent and intensive sampling was conducted and the outbreak was followed for 1 year. The data showed a persistent presence of S. Cerro with a high prevalence of infection in the herd. The dynamics of host and pathogen were modelled using a set of nonlinear differential equations. A more realistically distributed (gamma-distributed) infectious period using multiple stages of infection was considered. The basic reproduction number was calculated and relevance to the intervention strategies is discussed.

Salmonellae are a major group of foodborne pathogens known to affect both humans and animals. Dairy cattle are a known reservoir of these bacteria and human Salmonella infections have been associated with the consumption of improperly processed or contaminated dairy products. Many of the over 2500 known serotypes of Salmonella are known to infect cattle, resulting in asymptomatic to fatal salmonellosis. This study describes the course of a Salmonella outbreak and subsequent endemic infection on a dairy farm in Pennsylvania. The outbreak was initially detected when a few cows with clinical symptoms and one fatality were found to be infected with Salmonella enterica subsp. enterica serovar Typhimurium var. Copenhagan. Based upon sampling of the farm environment, Salmonella Typhimurium var. Copenhagan was succeeded within 3 months by Salmonella enterica subsp. enterica serovar Kentucky. Salmonella enterica subsp. enterica serovar Cerro ultimately supplanted Typhimurium var. Copenhagan and Kentucky in individual animals and environmental samples and persisted in the herd at high prevalence for almost 2 years. Since there were no obvious clinical consequences of the Salmonella Cerro infection, these data suggest that some serotypes of S. enterica subsp. enterica can behave as commensal organisms in dairy cattle and illustrate the difficulties of controlling Salmonella in milk production systems. The consistent finding of Salmonella in the environment reinforces the potential for human exposure to this pathogen and the need to understand the dynamics and ecology of Salmonella in dairy production settings.

Aims: To compare survival of Escherichia coli and faecal coliforms (FC) in bovine faeces deposited in a pasture or incubated in a controlled laboratory environment at temperatures within the same range., Methods and Results: Faecal samples from three cow herds were deposited as shaded and nonshaded cowpats in a field and incubated in a laboratory for one month at 21.1, 26.7 and 32.2 degrees C. Both FC and E. coli concentrations increased as much as 1.5 orders of magnitude both in the field and in the laboratory during the 1st week and subsequently decreased. In shaded cowpats, the die-off of E. coli and FC was significantly slower, and the proportion of E. coli in FC was significantly larger as compared with nonshaded cowpats. The die-off was faster in the field than in the laboratory at similar temperatures., Conclusions: FC and E. coli die-off rates were substantially lower in laboratory conditions than in the field within the same range of temperatures., Significance and Impact of the Study: This study underscores the importance of field data on survival of manure-borne FC and E. coli, and indicates that laboratory die-off rates have to be corrected to be used for field condition simulations.

Samples of bulk tank milk from dairies across the United States, taken as part of the National Animal Health Monitoring Dairy 2002 survey, were analyzed for the presence of several genes encoding virulence factors associated with enterohemorrhagic forms of Escherichia coli (EHEC) using real-time and conventional PCR assays. Samples from 859 farms in 21 states were collected and enriched in EC medium at 42.5 degrees C to amplify any E. coli present, and DNA was isolated from the resulting biomass. The eaeA gene encoding intimin, a virulence factor associated with enteropathogenic forms of E. coli and EHEC, was detected in 199 (23%) of the samples. Thirty-six samples (4.2%) were positive for eaeA, the gamma allele of the translocated intimin receptor (gamma-tir), found in EHEC strains of O157:H7, and one or both shiga-like toxin genes (stx1 and stx2), a combination that may be indicative of the presence of O157:H7 EHEC. Testing these 36 samples with a commercially available real-time PCR kit for detection of O157:H7 indicated that 5 samples could be contaminated with O157:H7. A multiplex PCR to detect the presence of fliC, rfbE, and hlyA genes found in O157:H7 reduced to 2 (0.2% of all samples) the number of samples likely to be contaminated with this organism. A strain of O157:H7 (eaeA+, gamma-tir+, stx2+, rfbE+, fliC+, hlyA+) was subsequently isolated from one sample. Thirty-four eaeA-positive samples did not contain detectable gamma-tir but did contain one or both of the stx genes suggesting the presence of EHEC strains other than O157:H7. These results indicate a low incidence of O157:H7 in bulk tank milk but suggest that a risk from other enteropathogenic and EHEC forms of E. coli may exist and that PCR targeting virulence factors associated with highly pathogenic forms of E. coli may be an effective means of detecting potential dangers in raw milk.

Purpose: To investigate how the performance characteristics of ultrasound tissue typing (UTT) affect the design of a population-based prostate dose-painting protocol., Methods and Materials: The performance of UTT is evaluated using the receiver operating characteristic curve. As the imager's sensitivity increases, more tumors are detected, but the specificity worsens, causing more false-positive results. The UTT tumor map, obtained with a specific sensitivity and specificity setup, was used with the patient's CT image to guide intensity-modulated radiotherapy (IMRT) planning. The optimal escalation dose to the UTT positive region, as well as the safe dose to the negative background, was obtained by maximizing the uncomplicated control (i.e., a combination of tumor control probability and weighted normal tissue complication probability). For high- and low-risk tumors, IMRT plans guided by conventional ultrasound or UTT with a one-dimensional or two-dimensional spectrum analysis technique were compared with an IMRT plan in which the whole prostate was dose escalated., Results: For all imaging modalities, the specificity of 0.9 was chosen to reduce complications resulting from high false-positive results. If the primary tumors were low risk, the IMRT plans guided by all imaging modalities achieved high tumor control probability and reduced the normal tissue complication probability significantly compared with the plan with whole gland dose escalation. However, if the primary tumors were high risk, the accuracy of the imaging modality was critical to maintain the tumor control probability and normal tissue complication probability at acceptable levels., Conclusion: The performance characteristics of an imager have important implications in dose painting and should be considered in the design of dose-painting protocols.

Aim: To test the hypothesis that Escherichia coli and enterococci bacteria have similar release rates and transport characteristics after being released from land-applied manure., Methods and Results: Turfgrass soil sod was placed into 200 cm long boxes that had the top two 25 cm sections separated to monitor the release and infiltration of bacteria, which affected bacteria transport in the rest of the box. Dairy manure with added KBr was broadcast on the top two sections. Boxes with either live or dead grass stand were placed under a rainfall simulator for 90 min. Runoff and infiltration samples were collected and analysed for Br, E. coli, enterococci and turbidity. Significant differences in release kinetics of E. coli and enterococci were found. A change from first-order release kinetics to zero-order kinetics after 1 h of rainfall simulation was observed., Conclusion: Differences in release rates but not in the subsequent transport were observed for E. coli and enterococci., Significance and Impact of the Study: Because both E. coli and enterococci are currently used as indicator organisms for manure-borne pathogens, the differences in their release rates may affect the efficiency of using these organisms as indicators.

Sixty-one Listeria monocytogenes strains from raw milk were analyzed with an automated repetitive element-based PCR (rep-PCR) system to examine the utility of this system for serotype grouping and to determine whether specific regional relationships could be identified. Results of the similarity analysis revealed two primary clusters of L. monocytogenes isolates. Cluster 2 exclusively contained serogroup 1/2a isolates; however, two 1/2a isolates were also found in cluster 1. Isolates of serogroups 1/2b, 4b, 3b, and 4c were also in cluster 1. Clusters 1 and 2 were separated at a relative similarity of 86%. Listeria species other than L. monocytogenes (L. ivanovii, L. seeligeri, L. welshimeri, L. grayi, and L. innocua) had similarity scores of less than 80% in pairwise comparisons with the L. monocytogenes isolates. Thus, this method may be useful for species identification once an isolate is characterized as Listeria. When rep-PCR fingerprints of the L. monocytogenes 1/2a isolates were compared, there was no apparent regional grouping. However, discrimination between isolates suggests that the rep-PCR assay might be useful for tracking L. monocytogenes 1/2a and for tracking isolates across regions or within smaller ecological niches. The automated rep-PCR method could not discriminate between serotypes 1/2b and 4b but may be useful for discriminating between 1/2a and other serotypes and for tracking isolates within serotype 1/2a.

Samples of bulk tank milk from dairies across the United States, taken as part of the National Animal Health Monitoring System Dairy 2002 survey, were analyzed for the presence of Salmonella enterica using a commercially available real-time polymerase chain reaction (PCR) kit. Samples from 854 farms in 21 states were collected and enriched in tetrathionate broth to amplify any salmonellae present, and DNA was isolated from the resulting biomass. One hundred one samples (11.8%) were shown to contain Salmonella enterica using the real-time PCR assay, whereas conventional culture techniques detected the pathogen in only 22 (2.6%) of the samples. A conventional PCR assay targeting a different gene from Salmonella enterica confirmed the presence of the organism in 94 of the real-time PCR-positive samples. Thus, assay of milk samples by real-time PCR indicates that the prevalence of Salmonella enterica in US bulk tank milk is substantially higher than previously reported.

Nutrients in animal manure are valuable inputs in agronomic crop production. Rapid and timely information about manure nutrient content are needed to minimize the risks of phosphorus (P) over-application and losses of dissolved P (DP) in runoff from fields treated with manure. We evaluated the suitability of a commercial hand-held reflectometer, a hydrometer, and an electrical conductivity (EC) meter for determining DP and total P (TP) in dairy manures. Bulk samples (n = 107) collected from farms across CT, MD, NY, PA, and VA were highly variable in total solids (TS) concentration, ranging from 11 to 213gL(-1), in suspensions' pH (6.3-9.2), and EC (6.2-53.3 dS m(-1)). Manure DP concentrations measured using the RQFlex reflectometer (RQFlex-DP(s)) were related to molybdate-reactive P (MRP(s)) concentrations as follows: RQFlex-DP(s) = 0.471 x MRP(s) + 1102 (r2 = 0.29). Inclusion of pH and squared-pH terms improved the prediction of manure DP from RQFlex results (r2 = 0.66). Excluding five outlier samples that had pH < or = 6.9 the coefficient of determination (r2) for the MRP(s) and RQFlex-DP(s) relationship was 0.83 for 95% of the samples. Manure TS were related to hydrometer specific gravity readings (r2 = 0.53) that were in turn related to TP (r2 = 0.34), but not to either RQFlex-DP or MRP. Relationships between suspensions' EC and DP or TP were non-significant. Therefore, the RQFlex method is the only viable option for on-site quick estimates of DP that can be made more robust when complemented with TS and pH measurements. The DP quick test can provide near real-time information on soluble manure nutrient content across a wide range of handling and storage conditions on dairy farms and quick estimates of potential soluble P losses in runoff following land applications of manure.

The objective of this study was to determine the prevalence of Salmonella, Listeria monocytogenes, and fecal coliforms in bulk tank milk in the United States. As part of the NAHMS Dairy 2002 survey, 861 bulk tank milk samples were collected from farms in 21 states. Milk was directly plated on selective agars for direct bacterial enumeration and was enriched in selective broths to increase detection sensitivity. Somatic cell counts (SCC) and standard plate counts (SPC) were also determined. Coliforms were detected in 95% (818 of 860) of the samples, and the average SCC was 295,000 cells/mL. Twenty-two samples (2.6%) were culture-positive for Salmonella, and 9 serotypes were identified: Montevideo (n = 7), Newport (n = 4), Muenster (n = 2), Meleagridis (n = 2), Cerro (n = 2), 44:Z36 (Z38) (n = 2), Dublin (n = 1), Anatum (n = 1), and 9, 12:nonmo-tile (n = 1). Listeria monocytogenes was isolated from 56 (6.5%) samples, and serotyping of these isolates yielded 5 serotypes (1/2a, 1/2b, 3b, 4b, and 4c). Of the L. monocytogenes isolates, 93% were serotypes 1/2a, 1/2b, and 4b, the most common human clinical isolates. Regional differences in L. monocytogenes and Salmonella prevalence were observed, but more studies are needed to determine the validity of these differences. There were no apparent relationships between SCC or SPC and incidence of Salmonella or L. monocytogenes. Although the prevalence of L. monocytogenes and Salmonella was low, these pathogens represent a potential risk to consumers of raw milk and raw milk products.

The purpose of this study was to determine the efficacy of a portable real-time PCR system in detecting Salmonella spp. in raw milk. The 200 bulk milk samples chosen for this study constituted a subset of the samples for a larger study; this subset contained 24 samples that were culture positive for Salmonella and 176 that were culture negative. Milk was both plated directly on selective agar and plated after enrichment in selective media. Presumptive Salmonella colonies were isolated by direct culturing of five samples, while Salmonella was isolated from the remaining 19 positive samples only after enrichment. Presumptive Salmonella isolates were serotyped, and isolates from 22 samples were confirmed to be Salmonella isolates. PCR assays of culture-positive milk prior to enrichment yielded no evidence of Salmonella. DNA extracts of bacterial pellets from the enriched samples were analyzed for Salmonella by real-time PCR with the Ruggedized Advanced Pathogen Identification Device (RAPID). Fifty-four samples from the enrichment pellets tested positive for Salmonella by real-time PCR. Two samples that tested positive for Salmonella by culture and serotyping tested Salmonella negative by real-time PCR. Serotyping identified isolates from these samples as Salmonella Montevideo. All DNA extracts of Salmonella Montevideo isolates tested positive for Salmonella by real-time PCR. Thirty-three samples tested negative by culture and positive by real-time PCR. These results indicate that the portable real-time PCR system appears to be a useful tool for detecting Salmonella in raw milk. Additionally, the combination of enrichment and real-time PCR techniques used in this study can yield results in 24 h, compared with the 48 to 72 h required for traditional culture.

Depending on the preparation method, we find two different structures of the Pb/Ge(111) system at a nominal coverage of 4 / 3 monolayer that exhibit different melting points. One is the well studied beta phase that melts at 270 degrees C, but the other is a new and metastable phase that melts at 330 degrees C. Using surface x-ray diffraction the atomic structure of both phases is found to be surprisingly similar. The difference in melting points can be explained by the distribution of the excess Pb present on the surface, which has a direct effect on the vacancy density. We propose a modified phase diagram, in which the melting temperature of the beta phase depends strongly on coverage.

Forty crossbred steers were used to determine the effects of carbohydrate supply site on the indigenous bacteria of the gastrointestinal tract. Steers were fitted with ruminal and abomasal infusion catheters and assigned randomly to one of eight groups in a complete randomized block design. The experimental period was 36 d. Treatments included: 1) a pelleted basal diet fed at 0.163 Mcal ME x (kg BW(0.75)) x 1 x d(-1) (LE); 2) the basal diet fed at 0.215 Mcal ME x (kg BW(0.75)) (-1) x d(-1) (HE); 3) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with ruminal infusion of starch hydrolysate (SH) (RSH); 4) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of SH (ASH); and 5) the basal diet fed at 0.163 Mcal ME x (kg BW(0.75))(-1) x d(-1) with abomasal infusion of glucose (AG). The total volume ofinfusate (5 kg x site(-1) x d(-1)) was equalized across treatments and infusion sites by infusion of water. Glucose and SH were infused at rates of 14.35 and 12.64 g x (kg BW(0.75)) x d(-1), respectively. Ruminal, cecal, and fecal samples were obtained on d 36. Ruminal pH was low (5.79) in LE steers and unaffected (P > 0.10) by increased energy intake or carbohydrate infusion. Cecal and fecal pH were 6.93 and 7.00, respectively, for LE steers. Increasing energy intake (P < 0.10) and the rate of carbohydrate infusion (P < 0.01) significantly decreased cecal and fecal pH compared with LE. Ruminal counts of anaerobic bacteria in LE steers were 8.99 log10 cells/g and abomasal carbohydrate infusion had no affect (P > 0.10) on these numbers. However, ASH and AG steers had approximately 1.5 log10 cells/g more (P < 0.01) cecal and fecal anaerobic populations. Ruminal, cecal, and fecal aerobic bacterial counts were 40, 22, and 23%, respectively, lower than anaerobic counts. Generally, aerobic counts responded similarly to the anaerobic counts. Less than 1% of the anaerobic bacteria enumerated in the rumen, cecum, and feces were coliforms, and 97% of the coliforms were Escherichia coli. Carbohydrate infusions resulted in only numerical increases in fecal coliform and E. coli concentrations (P > 0.10). Fecal E. coli were highly acid sensitive in all steers, with less than 1% surviving a 1-h exposure to low pH (2.0). This suggests that cecal or fecal pH is not a good indicator of acid resistance, and it supports the concept that there are other factors that may induce acid resistance.

The objective of this work was to test the ability of various available quick tests to determine ammonia concentration of poultry litters. A total of 136 samples was collected from brood chambers of poultry houses. Samples were equally divided between surface samples (top 25 mm) and core samples. Samples were frozen until analysis but received no further processing. Samples were analyzed for ammonia by autoanalyzer (standard) and several quick tests (conductivity, Quantofix N-Volumeter, and Reflectoquant). In addition, samples were analyzed by near-infrared spectroscopy by scanning samples using a large-sample transport device on a FOSS-NIRSystems model 6500 (64 co-added scans from 400 to 2,498 nm). Results showed that, although ammonia could be determined with reasonable accuracy by near-infrared spectroscopy using data in the 1,100 to 2,498 nm spectral range (final calibration R2 of approximately 0.90), none of the quick tests, including near-infrared, worked as well as previously found with dairy manures. The best results were found using the Quantofix or Reflectoquant (R2 of approximately 0.75), and conductivity worked only with the core samples (R2 of approximately 0.75). It is believed that interferences due to the presence of uric acid (spectroscopy, Quantofix, and Reflectoquant) and sodium bisulfate used to treat the litter (conductivity) were the cause of the decreased accuracies as compared to results achieved previously with dairy manures.

Animal agriculture is a significant source of atmospheric ammonia. Ammonia (NH3) volatilization represents a loss of plant available N to the farmer and a potential contributor to eutrophication in low-nitrogen input ecosystems. This research evaluated on-farm slurry treatments of alum or zeolite and compared three diets for lactating dairy cows in their effectiveness to reduce NH3 emissions. NH3 emissions were compared using a group of mobile wind tunnels. The addition of 2.5% alum or 6.25% zeolite to barn-stored dairy slurry reduced NH3 volatilization by 60% and 55%, respectively, compared to untreated slurry. The alum conserved NH3 by acidifying the slurry to below pH 5, while the zeolite conserved ammonia by lowering the solution-phase nitrogen through cation exchange. The use of alum or zeolite also reduced soluble phosphorus in the slurry. NH3 loss from fresh manure collected from lactating dairy cows was not affected by three diets containing the same level of crude protein but differing in forage source (orchardgrass silage vs. alfalfa silage) or neutral detergent fiber (NDF) content (30% vs. 35% NDF). NH3 losses from the freshly excreted manures occurred very rapidly and included the urea component plus some unidentified labile organic nitrogen sources. NH3 conservation strategies for fresh manures will have to be active within the first few hours after excretion in order to be most effective. The use of alum or zeolites as an on-farm amendment to dairy slurry offers the potential for significantly reducing NH3 emissions.

Ureteral injury from blunt abdominal trauma is very uncommon and is reported most often in children. We report a case mid-ureteral transection following blunt abdominal trauma that resulted in nephrectomy. There was also an associated aortic dissection. The pathophysiology, epidemiology, diagnosis, and treatment of blunt ureteral injury are also discussed.

The objective of this study was to investigate the feasibility of using near-infrared reflectance spectroscopy (NIRS) to determine nutrient concentrations in dairy manures. We assayed diverse dairy manures (n = 107), collected from dairy farms in the northeastern United States (CT, MD, NY, PA, and VA) by conventional means and NIRS for total C, total N, NH3-N, moisture, P, K, and pH. Samples were scanned from 400 to 2498 nm in polyethylene bags on a FOSS-NIR-Systems Model 6500 scanning monochromator equipped with a sample transport device. We developed calibrations using a one-out cross validation procedure under partial least-squares regression. Preliminary results showed that eight samples were outliers either because of inaccurate conventional analysis or because they were uncharacteristic (i.e., two samples had moisture content below 72%, while all others were above 78%). These outliers were removed from further consideration. Final calibration results with the remaining 99 samples demonstrated that NIRS can accurately determine the moisture (r2 = 0.945, root mean squared deviation or RMSD = 1.0%), total C (r2 = 0.950, RMSD = 0.40%), total N (r2 = 0.956, RMSD = 0.030%), and NH3-N (r2 = 0.967, RMSD = 0.013%) concentrations, but not P or K concentrations in dairy manures. In conclusion, NIRS was shown to be a viable alternative to conventional analysis procedures for determining moisture, total C, total N, and NH3-N in a very diverse set of dairy manures.

Manure nutrient analyses performed rapidly on the farm could be useful for nutrient management programs. The objective of this experiment was to evaluate six quick tests for their accuracy in estimating total manure N or NH4+-N. The quick tests included the hydrometer, electrical conductivity meter and pen, reflectometer, Agros N Meter, and Quantofix-N-Volumeter. The hydrometer was used to estimate total N, while the remaining tests were used to estimate NH4+-N. Samples (107) were collected from dairy farms in five northeastern states. Samples were analyzed for total N and NH4+-N by traditional laboratory methods and using each of the quick tests. Manure compositions ranged from 1.4 to 38.6% dry matter (DM), 0.9 to 9.5 kg/m3 total N, and 0.3 to 4.7 kg/m3 NH4+-N. The estimated concentration of total N or NH4+-N determined by each quick test was regressed against laboratory-determined values. The hydrometer did not estimate total N accurately. The strongest relationship for estimation of NH4+-N was with the Quantofix-N-Volumeter followed by the Agros N Meter, the reflectometer, and the electrical conductivity meter and pen. When the samples were split into high (>12%) and low (< or =12%) DM groups, in all cases the r2 for the regression equation was higher for the low DM group than for the high DM group. The Agros N Meter, the reflectometer, and the conductivity meter and pen did not perform well for the high DM group. These data indicate that several quick tests are viable options for measuring NH4+-N concentrations in dairy slurries and solids.

ICAM-3 is a preferred counterreceptor for the leukocyte alpha(L)beta2 integrin. It activates T cells through outside-in signaling, but polymorphonuclear leukocytes (PMN) are reported to be refractory to ICAM-3 stimulation. We found that engagement of ICAM-3 by a mAb (CAL3.10), which binds in the region where alpha(L)beta2 integrin binds, activates PMN homotypic aggregation and adhesion to surfaces. These functional changes were due to ICAM-3 outside-in signaling because aggregation and adhesion were beta2 integrin-dependent, tyrosine kinase and protein kinase C activities were activated, and there was a reorganization of the cytoskeleton. This reorganization and kinase activity was required for ICAM-3-, but not FMLP-, induced aggregation. This is not an Fc-mediated event as an appropriate anti-ICAM-3 F(ab')2 fragment still induced aggregation. Another anti-ICAM-3 Ab (HP2/19), which activates T cells, did not activate PMN. Strikingly, anti-ICAM-3 did not induce degranulation or cause an increase in surface beta2 integrin expression, so adhesion and aggregation were due solely to the activation of the constitutively expressed beta2 integrins. Aggregation in response to ICAM-3, but not FMLP, was compromised at lower cell densities, showing that beta2 integrin recruitment enhances aggregation under suboptimal conditions. We conclude that engagement of ICAM-3 stimulates PMN as well as T cells, but that the appropriate epitope varies between these two cells. ICAM-3 outside-in signaling reorganizes the cytoskeleton without causing degranulation, induces serine and tyrosine kinase activation, and activates existing surface beta2 integrins to a proadhesive state.

ICAM-3 is expressed at high levels on myeloid leukocytes, but its function on these cells is unknown. We tested the hypothesis that it transduces outside-in proinflammatory signals using immobilized mAbs to engage ICAM-3 on freshly isolated human monocytes and neutrophils. Two immobilized Abs that recognize epitopes in the extracellular domain 1 of ICAM-3, which is critical for recognition by the alphaL/beta2 integrin, potently induced secretion of MIP-1alpha, IL-8, and MCP-1 by monocytes and triggered IL-8 secretion by neutrophils. These chemokines are products of immediate-early genes that are induced when myeloid cells are activated. Chemokine secretion induced by "triggering" Abs was greater than that induced by isotype-matched immobilized Abs against ICAM-1, ICAM-2, PECAM-1, control Igs, or immobilized control proteins. Coengagement of ICAM-3 and Fc receptors (FcgammaRI or FcgammaRII) was required for maximal chemokine secretion by monocytes. Microscopy documented that there is also dramatic spreading of monocytes when surface ICAM-3 is engaged by immobilized Abs. Spreading was induced by Fab and F(ab')2 fragments of triggering anti-ICAM-3 mAb, demonstrating direct outside-in signaling, but was not required for chemokine secretion. These experiments indicate that ICAM-3 may transmit outside-in signals when it is engaged by beta2 integrins during myeloid cell-cell interactions in inflammatory lesions. Binding of Fc receptors by Ig in the local environment can amplify the responses.

Discharge of the newborn within 24 to 48 hours after birth makes it more difficult to detect some congenital malformations and increases the need for careful examination and review of the history of the pregnancy, delivery, and nursery course. Progressive physiologic changes after birth, especially in the cardiovascular system, precede the development of signs indicative of disease for certain congenital malformations. Discharge before these changes occur may delay their detection because the newborn is not being monitored by medical or nursing caregivers. The AAP Committee on the Fetus and Newborn has published guidelines for criteria for safe discharge and follow-up evaluation to help create a safe situation for such early discharges. Some specific observations at birth may lead to earlier diagnosis. Careful attention to subtle differences between the initial and follow-up examination, such as a changing cardiac murmur or quality of pulses or abdominal fullness, may provide clues to the diagnosis of congenital malformations. Coordinated suck and swallow with successful feeding and passage of stool and urine within 24 hours after birth should occur before discharge. Reports of feeding difficulties should be reviewed. Although a thorough examination is facilitated by a sleeping infant, documentation of a normal pitched cry helps in the evaluation of the upper airway. Parents should be counseled about signs of illness that warrant medical attention, and early follow-up is needed to detect problems early enough to intervene effectively. In addition, although passage of a feeding tube through each nare and to the stomach with aspiration and measurement of gastric volume is not a routine procedure in the well, term newborn, this may be a useful early diagnostic tool in infants with signs or a maternal or nursery history suggestive of nasal or GI obstruction.

When mixed ruminal bacteria were starved in vitro for 24 h, cellular ATP decreased, but there was little change in cell protein. Starved ruminal bacteria derived most of their ATP from cellular polysaccharide. Because polysaccharide declined at a first-order rate of 23%/h, it was possible to estimate the endogenous polysaccharide utilization rate at various stages of starvation by multiplying the amount of utilizable polysaccharide remaining at each time point by 0.23. The bacteria initially had a rate of soluble carbohydrate fermentation that was > 717 micrograms of hexose equivalent/mg of protein per h. Starvation had little impact on the rate of soluble carbohydrate fermentation until 8 to 12 h, and the endogenous polysaccharide utilization rate was < 10 micrograms of hexose/mg of protein per h. The bacteria digested ball-milled cellulose at a rate of 24 micrograms of hexose/mg of protein per h for 8 to 12 h. Even bacteria that had been starved for 24 h fermented cellulose at a rate of 16 micrograms of hexose/mg of protein per h. The rate of methane production was initially 70 nmol of methane/mg of protein per min. Short periods of starvation (< 12 h) had little impact on methane production, but longer times caused an almost complete inhibition of methanogenesis. The rate of amino acid deamination was initially 31 nmol of ammonia/mg of protein per min, and the critical phase of starvation was again 8 to 12 h. Ruminal bacteria that were harvested at 24 h after feeding had 10-fold less polysaccharide than did bacteria that were harvested at 2 h after feeding, but this polysaccharide supported high rates of soluble carbohydrate and cellulose fermentation, deamination, and methane production.

The efficacy of a benzodiazepine was compared with that of a neuroleptic for the rapid tranquilization of patients presenting at a psychiatric emergency room service. Thirty-seven highly agitated patients exhibiting psychotic symptoms were randomly assigned to receive either 2 mg lorazepam or 5 mg haloperidol as needed every 30 min for 4 h. Administration route was either intramuscular injection or oral concentrate. Symptom ratings were conducted each hour using double-blind procedures. Both medications reduced symptom ratings on the Brief Psychiatric Rating Scale and Global Clinical Impression of Overall Symptom Severity Scale. Global Clinical Impression scores for the two medication groups did not differ significantly either at baseline or at 4 h after entry into the study. However, Global Clinical Impression scores of patients in the lorazepam group were less severe at intermittent ratings. The groups did not differ on the Brief Psychiatric Rating Scale at any rating time. No differences were found either in the number of doses administered or in the administration route selected. Given the potential for severe extrapyramidal symptoms developing hours or days after a single dose of haloperidol, lorazepam may provide an excellent alternative for the rapid tranquilization of the acutely agitated psychotic patient in the emergency room setting.

The predominant ruminal bacteria that were obtained from a 10(8) dilution of ruminal fluid could be maintained as a mixed population for long periods as long as the bacteria were provided with a complex mixture of carbohydrates. Growth of predominant ruminal bacteria in carbohydrate-limited, ammonia-excess, continuous cultures (0.07/h) had a low requirement for maintenance energy, but the nongrowth energy dissipation of ammonia-limited, carbohydrate-excess, predominant ruminal bacteria was approximately 10-fold higher (0.96 vs. 0.09 mg of hexose equivalent/mg of protein per h, respectively). Mathematical derivations indicated that this additional nongrowth energy dissipation could be accommodated by an energy spilling function that was independent of the growth rate. Peptides and amino acids had little impact on the yield of carbohydrate-limited, ammonia-excess, continuous cultures (0.07/ h), but amino N greatly increased the growth rate and yield of excess-energy batch cultures. The change in growth rate and yield that was dependent on amino N indicated that the energy-excess batch cultures had the same capacity to spill energy as did the ammonia-limited, carbohydrate-excess, predominant ruminal bacteria (0.80 vs. 0.86 mg of hexose equivalent/mg of protein per h, respectively). When the energy-excess batch cultures were provided with amino N, the growth rate increased, the difference in anabolic and catabolic rates was smaller, and less energy was spilled.

A steady-state model of the production, absorption, passage, and concentration of ruminal VFA and pH is developed from published literature data and is structured to use the feed descriptions and inputs from the net carbohydrate and protein system. Included are the effects of pH on growth rate and yield of structural and non-structural carbohydrate-fermenting bacteria; production of acetate, propionate, butyrate, lactate, and methane; conversion of lactate to VFA; ruminal absorption of acids; and prediction of ruminal pH from dietary measures and from ruminal buffering and acidity. The root mean square error of predicted total VFA concentration was 12 mM. Individual VFA fractions were inadequately predicted. In a review of literature data, effective NDF (eNDF) provided a better correlation with ruminal pH than forage or NDF. Digestion rate of NDF remained at normal levels above pH 6.2, which corresponds to a minimum eNDF of 20% of dietary DM. Further research is needed to determine the individual VFA produced from carbohydrate fractions at various pH, the appropriateness of partitioning the starch and pectin carbohydrate pool into slowly and rapidly degraded fractions, and the effect on microbial yield, total tract digestibility, and predicted energy values of feeds.

Gram-negative, ionophore-resistant ruminal bacteria and Gram-positive, ionophore-sensitive species bound similar amounts of [14C]lasalocid, but neither group bound large amounts of [14C]monensin. Membrane vesicles also bound more lasalocid than monensin (P < .05). The binding was first-order at low cell or vesicle concentrations and saturable at high cell or vesicle densities. Streptococcus bovis was inhibited by both monensin and lasalocid (5 microM), but cells that were re-incubated in medium lacking ionophore grew rapidly. Lasalocid-treated cells grew very slowly when they were resuspended in fresh medium. Based on these results, it seemed that lasalocid had a higher affinity for bacterial membranes than monensin. Mixed bacteria, however, bound nearly equal amounts of [14C]monensin and [14C]lasalocid (P > .05). Monensin binding was greatly reduced when the mixed ruminal bacteria were pretreated with Tris+EDTA (P < .05), but Tris+EDTA did not affect the binding of lasalocid. Mixed ruminal protozoa always took up more lasalocid than monensin (P < .05), but feed particles bound equal amounts of [14C]lasalocid and [14C]monensin (P > .05). Based on the binding capacity of mixed ruminal bacteria, ruminal protozoa, and feed particles, there would be little free ionophore in ruminal fluid.

The question of toxic interactions resulting from combinations of lithium and neuroleptic drugs is largely based on anecdotal reports. We replicated the methods of Miller and Menninger (1987) who reported that 27% of manic patients on treatment with lithium and neuroleptics developed toxicity. We found no cases of neurotoxicity as defined in the earlier report. Pharmacologic mechanisms and differences in the clinical findings of the two studies are discussed.

Strain SR, a monensin-sensitive, ammonia-producing ruminal bacterium, grew rapidly on arginine and lysine, but only if sodium was present. Arginine transport could be driven by either an electrical potential or a chemical gradient of sodium. Arginine was converted to ornithine, and it appeared that ornithine efflux created a sodium gradient which in turn drove arginine transport. There was a linear decline in arginine transport as pH was decreased from 7.5 to 5.5, and the cells did not grow at a pH less than 6.0. The Eadie-Hofstee plot was biphasic, and arginine could also be taken by a high-capacity diffusion mechanism. Because arginine was a strong inhibitor of lysine transport and lysine was a weak inhibitor of arginine transport, it appeared that both lysine and arginine were taken up by an arginine-lysine carrier which had a preference for arginine. The rate of lysine fermentation was always proportional to the extracellular lysine concentration, and facilitated diffusion was the dominant mechanism of lysine transport. When SR was grown in continuous culture on arginine or lysine, the theoretical maximal growth yield was similar (13 g of cells per mol of ATP), but the apparent maintenance energy requirement for arginine was greater than lysine (9.4 versus 4.4 mmol of ATP per g of cells per h). On the basis of differences in yield and maintenance energy, it appeared that active arginine transport accounted for approximately 40% of the total ATP.

Older studies on neuroleptic pharmacokinetics had problems in methodology and laboratory techniques. High performance liquid chromatography (HPLC) and combinations of techniques are used now. Clozapine levels are related to dose, age, sex, and smoking. Fluphenazine decanoate gives more predictable levels than oral, and 25 mg/2 weeks is associated with the lowest relapse rate. A therapeutic window with haloperidol is not well established; increased side effects at higher doses may account for the worsening seen. Half-lives much longer than previously quoted are now described. Children and the elderly are more susceptible to side effects of neuroleptics. Studies of the neuroleptic threshold and brain imaging indicate that doses used today are excessive. Nonresponders can distort dose effect relationships. Plasma levels are not useful routinely; they are of use in ruling out pharmacokinetic factors in nonresponse and when side effects are severe.

Prospective data of cardiovascular mortality in relation to the systolic blood pressure of women are scarce, especially when combined with other risk factors. The association between systolic blood pressure and cardiovascular mortality was therefore studied in a 10-year follow-up of a population of 13,740 Dutch women, born between 1911 and 1925 who participated in a population-based breast cancer screening project (the DOM Project). Age-adjusted mortality rates over the 10-year follow-up period suggest a J-shaped pattern of cardiovascular mortality according to level of systolic blood pressure. Age-adjusted total cardiovascular, coronary, and cerebrovascular mortality rate ratios were significantly greater than 1.0 among women with elevated systolic blood pressure. Within categories of other risk factors (obesity index, diabetes mellitus, current smoking, and use of antihypertensive medicines) the age-adjusted cardiovascular rate ratios did not show confounding by any of these variables. A very high increase in cardiovascular mortality was observed among hypertensive diabetic women. This study shows that elevated systolic blood pressure is associated with increased rates of cardiovascular mortality for women in this age group.

The dissociation and association behaviour of 70-S ribosomes of Escherichia coli has been studied. It has been shown that the dissociation-association reaction can be both a real dynamic equilibrium and a non-equilibrium reaction, dependent upon the ionic conditions of the solvent. At relatively high ionic strength (I = 0.15 M or more) the dissociation-association reaction is an equilibrium reaction, whereas at lower ionic strength (I = 0.1 M or less) there is no dynamic equilibrium between 70-S ribosomes and its subunits. In the latter case a hysteresis in the dissociation-association reaction is observed. Whether there is a dynamic equilibrium or not can be demonstrated by a single centrifugation experiment, using the analytical ultracentrifuge.

When the therapeutic alliance between physician or psychotherapist, and epileptic patient is seriously disrupted (non-compliance) group psychotherapy is capable of bringing about marked changes in coping with the epileptic condition. Even a brief therapy of 20 sessions with epileptic young people undergoing initial vocational training contributes to their learning to perceive problems present in their vocational-social development, as well as various disease phenomena and therapeutic possibilities. Eight young adults aged 18-20 years who had been referred to the Annedore Leber Vocational Training Centre for psychological and neurological examination suffered from frequent seizures, which had in each case been attributable to non-compliance. On completion of therapy, serum levels of anti-epileptic drugs had reached the therapeutic range. None of them failed to complete their vocational training.

Amino terminal sequence analyses were performed on the H and L chains of the idiotypically related IgMlambda and IgGkappa paraproteins isolated from the sera of a patient, Br. The N-terminal 41 residues of the Br k-chain belonged to the Vkiii subgroup, and L chains derived from BrIgMlambda revealed a blocked N-terminus characteristics of lambda-chains. Comparative sequence analysis of the Br mu- and gamma-chains indicated that, although both possessed an unblocked N-terminal glutamic acid, the respective VH regions belonged to seperate subgroups. The N-terminal 27 residues of the Br mu-chain reflected a typical VHiii subgroup sequence. The Br gamma-chain sequence demonstrated a VHI pattern with an unblocked N-terminus. These structural data stand in contrast to previously reported serologic evidence, which indicated that the BrIgMlambda and BrIgGkappa proteins possessed highly similar Vh-associated idiotypic determinants. Final interpretation of these findings of similar Vh idiotypic determinants expressed by H chains belonging to seperate Vh subgroups must await complete sequence analysis of hypervariable segments of the Br gamma- and mu-chains.

This study investigates the developmental potential of the extraembryonic mesodermal cells of the early chick blastoderm. [3H]Thymidine-labeled mesodermal fragments from the extraembryonic area pellucida (AP) and area opaca vasculosa (AOV) were transplanted into the AP or AOV of nonlabeled host blastoderms in culture, and their fate followed autoradiographically. All the homotopically transplanted mesodermal cells differentiated in accordance with their normal fates. However, not all the heterotopically transplanted mesodermal cells did so, for some of the stage 8 AP extraembryonic mesodermal cells (normally nonerythropoietic) gave rise to blood cells when transplanted into the AOV. We also observed that the stage 4-5 AOV mesoderm continues to migrate peripherally when heterotopically transplanted into the AP, at a time when the AP mesodermal cells are nonmigratory. In support of our premise that the stage 8-9 AP extraembryonic mesoderm has the potential to form blood, we observed a clear-cut production of hemoglobin when the latter mesoderm was co-cultured on coverslips with stage 4 AOV endoderm.

We use a standing-drop culturing method to investigate the effect on mesodermal erythropoiesis of ectoderm and endoderm from the area opaca vasculosa (AOV) and area pellucida (AP) of stage-4 chick blastoderms. We find that ectoderm from the AOV and ectoderm and endoderm from the AP exert an inhibitory influence on mesodermal erythropoiesis. This inhibitory influence is coupled with the tendency of the explants to spread out and become flattened in culture. In contrast, endoderm from the AOV is found to be stimulatory, in agreement with previous studies. We correlate these in vitro inhibitory and stimulatory influences with the morphogenetic patterns that occur during normal development.

Investigators have previously reported good retention, antifertility efficacy, and oviduct polymer compatibility in rabbit oviducts in studies of both short-term and chronic occlusion with high viscosity silicone polymer. The present study attempts to determine the chronic effects of the silicone polymer installed into the oviducts of 10 rhesus monkeys. Unlike former studies with rabbits, the polymer was installed into the fimbrial end of the monkey's oviducts because of the complexity of the uterotubal junction's musculature. Studies with light and scanning electron microscopy were conducted to examine tissue reaction to plug retention. Despite our major modification of the installation technique, we obtained a retention rate of 50%. In addition, there was no evidence of inflammation or tissue distortion, and the polymer plugs were not affected by menstrual bleeding.

This scanning electron- and light-microscopic study traces the morphogenesis of the yolk-sac vascular system and extraembryonic coelom in the chick blastoderm. The fate of the mesodermal cells in both the area opaca vasculosa (AOV) and the area pellucida (AP) is followed, and the cellular patterning in these two areas is compared. We describe new details of the formation of coelom lining in the AOV, and new observations of the tendency of the intravascular blood island cells of the AOV to become flattened and attenuated. The morphogenesis of the blood system and coelom is analyzed in terms of polarized morphological patterns with coordinates in two modes:proximodistal (from the AP to the AOV) and dorsoventral (from the ectoderm to the endoderm). By highlighting differences in the methods of formation of blood vessels and coelom lining in the AP and AOV, this paper resolves some paradoxes in the literature.

An effective filariasis research and control programme has been recently established in Tahiti. This article describes the methods used for preliminary investigation of the clinical manifestations of the disease, the prevalence of the parasite and the role of the vector mosquitos. Control was effected by eliminating mosquito breeding-places and administering diethylcarbamazine to the population. An estimate is made of the costs and comparative value of the various procedures which were tried.