Research Note: Repetitive element-based polymerase chain reaction genotyping improves efficiency of Salmonella surveillance in a model broiler production system.

The genetic relatedness and antimicrobial susceptibility profiles of Salmonella isolated from poultry and their environment were determined. One broiler breeder flock (BBF1) and 2 broiler flocks (BF1 and BF2) were reared over a 1.75-year period on the same poultry research farm. Hatching eggs were obtained from BBF1 to produce BF1 chicks, while BF2 chicks were progeny of a separate, unsampled broiler breeder flock. BF1 and BF2 were reared in the same housing facilities but 6 mo apart. Salmonella isolates were collected via litter sock sampling (BF1), cecal excision (BF1 and BF2), or cloacal swabs (BBF1). Serotyping identified Salmonella enterica subsp. enterica serovar Altona (SA) in BBF1 and S. enterica subsp. enterica serovar Senftenberg (SS) in BF1 and BF2. Genotypic fingerprinting was achieved with Rep-PCR using the (GTG)5 primer and revealed sequence homology among Senftenberg isolates from BF1 and BF2. For each isolate, the minimum inhibitory concentration was determined for 27 antimicrobial agents using Sensititre plates with formularies specific to antimicrobials used in poultry production or those used to control gram negative pathogens. Isolates from the 3 flocks were resistant to clindamycin, erythromycin, novobiocin, penicillin, and tylosin tartrate and demonstrated intermediate resistance to azithromycin, florfenicol, and spectinomycin. These data demonstrated that serovar Altona and Senftenberg were harbored by poultry, the latter appeared to persist in broiler flocks, and both serotypes shared similar patterns of antimicrobial susceptibility in an integrated research operation. In the case of multiple Salmonella isolates, combining genotypic fingerprinting methods with serotyping of representative isolates would reduce the number of samples required for serotyping and more clearly identify relatedness of isolates. These methods facilitate effective surveillance in poultry production systems, thus allowing for implementation of precise Salmonella control measures.

The effects of coarse corn and refined functional carbohydrates on the live performance and cecal Salmonella prevalence in coccidiosis-vaccinated broilers1.

The interaction between corn particle size and feed additives as it pertains to broiler live performance has been overlooked. This study evaluated the effects of corn particle size and refined-functional carbohydrates (RFC; 100 g/MT) on live performance and Salmonella prevalence in coccidiosis-vaccinated broilers. The following treatments were applied: fine corn (FC), coarse corn (CC), FC+RFC, CC+RFC, and CC+SAL (salinomycin). A natural, non-experimental necrotic enteritis (NE) outbreak began at 12 D of age, and mortality was impacted by dietary treatments. The use of RFC was observed to increase NE-associated mortality compared to broilers fed CC+SAL (P ≤ 0.10). At 19 D, greater than 50% of all broilers were found to be Salmonella-positive; however, at 48 D the use of RFC was shown to decrease cecal Salmonella prevalence. Although differences in early mortality were observed, coccidiosis-vaccinated broilers fed CC or CC+RFC exhibited similar BW and FCR as broilers fed CC+SAL at 48 D (P ≤ 0.05). These data suggested that CC use after 10 D may provide value in a production system free of antibiotic growth promoters and coccidiostats by ameliorating live performance losses associated with coccidiosis vaccination. Further research is warranted to determine how RFC and CC specifically affect Eimeria cycling and the immune response following coccidiosis vaccination and an NE challenge.

The effect of refined functional carbohydrates from enzymatically hydrolyzed yeast on the transmission of environmental Salmonella Senftenberg among broilers and proliferation in broiler housing.

Hatching eggs collected from resident broiler breeders at 48 wk of age were used to produce male and female chicks that were assigned sex separately to 96 new litter pens and fed either a 0 or 50 g/MT RFC (refined functional carbohydrate feed additive derived from yeast) diet. There were 24 replicate pens of 12 broilers each per diet per sex. Feed intake and BW were determined at 14, 28, and 42 d of age. Litter was sampled by pen using sterile socks at 35 d and tested for Salmonella spp. using an enzyme linked fluorescence assay method. Salmonella spp. was isolated from 7 of 48 control-fed broiler pens but no RFC-fed pens (P ≤ 0.05). Thereafter, 48 males and 48 females were selected based on litter Salmonella presence and RFC treatment. The cecas of these broilers were aseptically excised after feed withdrawal and lairage and tested for presence of Salmonella spp. There were 18 of the 48 control-fed broilers confirmed positive from litter-positive pens but none from litter-negative pens fed RFC. The serovar of litter and cecal Salmonella isolates was Salmonella enterica subsp. enterica serovar Senftenberg (S. Senftenberg). Female broilers that were fed RFC exhibited greater BW at 28 d (P ≤ 0.05) and 42 d (P ≤ 0.05) while RFC-fed males exhibited improved feed efficiency during the 15-28 d period (P = 0.06). These data demonstrated that dietary RFC reduced the prevalence of Salmonella in the litter and ceca of broilers when fed continuously while not being detrimental to broiler live performance.

Effect of refined functional carbohydrates from enzymatically hydrolyzed yeast on the presence of Salmonella spp. in the ceca of broiler breeder females.

Broiler breeders hatched from Salmo-nella negative grandparents received either zero or 50 g/MT of refined functional carbohydrates (RFC) in their diets from d of placement to end of lay. There were no other treatments used. Pullets and cockerels were reared separately in an enclosed litter-floor house to 21 wk of age when 28 randomly selected pullets from each diet were transferred to individual cages for an additional 14 d before they were killed, and their ceca were excised aseptically and tested for Salmonella spp. The remaining birds were transferred to a two-thirds slat and one-third litter curtain-sided laying house. There were 8 pens of 60 to 65 females and 8 to 18 males, depending upon flock age and housing type, fed each diet, and there was no effort made to isolate pens from typical daily foot traffic between pens. At 51 wk of age, male progeny broiler chicks were hatched and received either zero or 50 g/MT of RFC to complete a 2 × 2 design with 4 replicate pens of 12 males per interaction. All broilers were tested for cecal Salmonella spp. at 34 d of age. Ceca were collected from 30 breeder hens from each treatment at 64 wk of age and tested for Salmonella spp. Of the ceca sampled at 23 wk from the control pullets, 71.4% were found to contain Salmonella spp., while none of the ceca from the RFC pullets tested positive. Of the ceca sampled from the control hens at 64 wk, 40% were found to contain Salmonella spp., while none of the ceca from the RFC hens tested positive. Salmonella spp. was isolated from broilers in one pen of the control broilers that were also progeny of control breeders out of 4 replicates but not from any pens in which the breeders had been fed RFC. These data demonstrated that RFC reduced natural Salmonella spp. colonization of broiler breeder hen and broiler progeny ceca during a complete production cycle.

EphA4 activity causes cell shape change and a loss of cell polarity in Xenopus laevis embryos.

The Eph family of receptor tyrosine kinases and their ephrin ligands are believed to limit cell-cell interactions during embryonic development via a repulsive mechanism. Little is known, however, about the intracellular effects of Eph signaling that lead to cellular repulsion. We have used scanning and transmission electron microscopy to examine the effects of EphA4 catalytic activity on cells in early embryos of Xenopus laevis. We show that ectopic EphA4 catalytic activity in superficial blastula cells leads to a more rounded cellular morphology, a loss of apical microvilli, and a loss of the apical/basolateral boundary, in addition to the previously reported loss of cell adhesion. These effects indicate that these epithelial cells have lost their apical/basolateral polarity. We also show that EphA4 catalytic activity causes a preferential loss of adherens junctions, compared to tight junctions. Furthermore, EphA4 catalytic activity was found to result in a change in filamentous actin levels in blastomeres. These results taken together suggest that the actin cytoskeleton might be a target of EphA4 signaling.

High-fat diet elevates blood pressure and cerebrovascular muscle Ca(2+) current.

Dietary fat contributes to the elevation of blood pressure and increases the risk of stroke and coronary artery disease. Previous observations have shown that voltage-gated Ca(2+) current density is significantly increased in hypertension and can be affected by free fatty acids (FAs). We hypothesized that a diet of elevated fat level would lead to an increase in blood pressure, an elevation of L-type Ca(2+) current, and an increase in saturated FA content in vascular smooth muscle cell membranes. Male Osborne-Mendel rats were fed normal rat chow or a high-fat diet (Ob/HT group) for 8 weeks. Blood pressures in the Ob/HT group increased moderately from 122.5+/-0.7 to 134.4+/-0.8 mm Hg (P<0.05, n=26). Voltage-clamp examination of cerebral arterial cells revealed significantly elevated L-type Ca(2+) current density in the Ob/HT group. Voltage-dependent inactivation of the Ob/HT L-type channels was significantly delayed. Total serum FA contents were significantly elevated in the Ob/HT group, and HPLC analyses of fractional pools of FAs from segments of abdominal aorta revealed that arachidonic acid levels were elevated in the phospholipid fraction in Ob/HT. No differences in vascular membrane cholesterol contents were noted. Plasma cholesterol was significantly elevated in portal venous and cardiac blood samples from Ob/HT rats. These findings suggest that an elevation of plasma FAs may contribute to the development of hypertension via a process involving the elevation of Ca(2+) current density and an alteration of channel kinetics in the vascular smooth muscle membrane.

Inhibitors of V-type ATPases, bafilomycin A1 and concanamycin A, protect against beta-amyloid-mediated effects on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction.

The functional viability of cells can be evaluated using a number of different assay determinants. One common assay involves exposing cells to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), which is converted intracellularly to a colored formazan precipitate and often used to assess amyloid peptide-induced cytotoxic effects. The MTT assay was employed to evaluate the role of endosomal uptake and lysosomal acidification in amyloid peptide-treated differentiated PC12 cell cultures using selective vacuolar-type (V-type) ATPase inhibitors. The macrolides bafilomycin A1 (BAF) and concanamycin A (CON) block lysosomal acidification through selective inhibition of the V-type ATPase. Treating nerve growth factor-differentiated PC12 cells with nanomolar concentrations of BAF or CON provides complete protection against the effects of beta-amyloid peptides Abeta(1-42), Abeta(1-40), and Abeta(25-35) and of amylin on MTT dye conversion. These macrolides do not inhibit peptide aggregation, act as antioxidants, or inhibit Abeta uptake by cells. Measurements of lysosomal acidification reveal that the concentrations of BAF and CON effective in reversing Abeta-mediated MTT dye conversion also reverse lysosomal pH. These results suggest that lysosomal acidification is necessary for Abeta effects on MTT dye conversion.

Scar-associated malignant melanoma and squamous carcinoma in situ.

The development of cutaneous neoplasms is a known sequela of chronic scars, squamous carcinoma being most common. We have described an elderly patient with both squamous carcinoma in situ and malignant melanoma in different scars. The coexistence of the lesions suggests a common pathogenesis.

Reforming Medicare: the limited framework of political discourse on equity and economy.

Medicare, the major program that organizes the delivery and financing of health care for the elderly in the United States, is being rapidly and significantly changed in order to bring Federal expenditures for health care under control. Questions of 'equity', 'justice' and 'access to health care' (that have long been associated with liberal ideology) have lost discursive currency within the realm of acceptable political debate that now focuses on 'economy' and the restoration of 'competitive market forces' to the health care industry (a point of view associated with conservative ideology). Pluralistic analyses of American health care policy most often focus on the differences between liberals and conservatives and could only explain the current bipartisan effort to reorganize Medicare as a defeat for liberals and as a vindication for the conservative perspective during a period of economic crisis. This essay develops the alternative point of view that American political debate on health care, among and between liberals and conservatives, has always taken place within a space bracketed by well defined limits established by widespread support for the market model of health care. The strength and dominance of this model that organizes and supports the private production of health care for profit is far more important in explaining the continuity in American health care policy over time and the recent policy adjustments than any examination of ideological differences between political conservatives and liberals. After analyzing the limited framework of debate structured by the market model of health care, this paper critically examines the recent changes in Medicare and challenges the market model on empirical grounds. Finally, the author returns to a discussion of the implications of these changes for equity and justice.

Characteristics of a human epidermal squamous carcinoma cell line at different extracellular calcium concentrations.

A continuous line derived from a human skin squamous cell carcinoma has been grown in media of high, normal and low Ca2+ concentrations. The growth rate was unaffected by the Ca2+ levels even though morphological changes were observed. Desmosomes were absent at low Ca2+ and areas of cell piling were observed at high Ca2+. Cell protein staining patterns on polyacrylamide gels were identical for cells grown at the three Ca2+ levels. The variations were minor for the glycoproteins reacted with 125I-conA. Lactoperoxidase iodination revealed changes in cell surface proteins, most markedly in the emergence of new proteins at high Ca2+.

Diagnosis of Legionella micdadei pneumonia from cytologic specimens.

Legionella micdadei is a recently described opportunistic pulmonary pathogen that produces an acute, suppurative pneumonia in patients receiving steroid therapy. Most prospective diagnoses have been made by open lung biopsy. We present a case in which the diagnosis was made from cytologic material. The clinicopathologic features of L. micdadei pneumonia are discussed, and criteria for diagnosis from cytologic specimens are presented.

Fine needle aspiration of thoracic extramedullary hematopoiesis.

Thoracic manifestations of extramedullary hematopoiesis (EMH) are well known clinically, radiologically and pathologically; it is generally confirmed histologically by open biopsy or postmortem examination. We report a case of EMH diagnosed by percutaneous fine needle aspiration (FNA) in a patient with long-standing, acquired, sideroblastic anemia. The aspirate was very cellular and composed of normal bone marrow elements with an erythroid to myeloid cell ratio of 3 to 1. Megakaryocytes were abundant but constituted less than 1% of the total cell population. This case illustrates that the diagnosis of EMH is possible by FNA and that thoracotomy for diagnostic purposes can be circumvented.

Megakaryocytic leukemia; identification utilizing anti-factor VIII immunoperoxidase.

Coagulation Factor VIII is produced by endothelial cells and megakaryocytes. Antibody directed against Factor VIII or its associated antigens has been shown to be a sensitive marker for both normal and neoplastic endothelial cells. Its use to identify neoplastic megakaryocytes has not been described. We used immunoperoxidase localization of Factor VIII to identify megakaryocytes and immature megakaryocytic precursors in a case of megakaryocytic leukemia.

Opportunistic pneumonia: a clinicopathological study of five cases caused by an unidentified acid-fast bacterium.

Five patients had opportunistic pulmonary infection caused by acid-fast bacilli, unusual clinical presentations and a unique pathological picture. Clinically, these cases mimicked septic pulmonary emboli or bacterial pneumonia. The infection was temporally related to high-dose corticosteroid therapy, given for renal-transplant rejection in four patients and for therapy of lymphocytic lymphoma in one. Histologic sections of lung-biopsy or autopsy material showed an acute suppurative pneumonia with dense alveolar infiltration by neutrophils, without granuloma formation or caseous necrosis. Predominantly intracellular acid-fast bacilli were present. The organism failed to grow in culture on routine bacterial, fungal and mycobacterial mediums. This unusual and possibly new acid-fast organism is a probable cause of suppurative pneumonia in impaired hosts receiving corticosteroid therapy.

Separation of epidermal layers of the newborn rat.

A method is presented for the separation of epidermal strata by the successive elimination of either the basal or basal and spinous cells with 0.24 M NH4Cl at pH 9.5. Histologic evidence suggests that the residual epidermal strata obtained after incubation of the skin with NH4Cl are reproducible; hence, this technique circumvents loss of granular layer histidine-rich protein inherent with trypsin separation and provides an effective procedure for biochemical analysis of arginine-rich and lysine-rich proteins in the various differentiating epidermal cells.