Real-time quantitative PCR measurement of ileal Lactobacillus salivarius populations from broiler chickens to determine the influence of farming practices

A real-time quantitative PCR assay targeting a 16S-23S intergenic spacer region sequence was devised to measure the sizes of populations of Lactobacillus salivarius present in ileal digesta collected from broiler chickens. This species has been associated with deconjugation of bile salts in the small bowel and reduced broiler productivity. The assay was tested as a means of monitoring the sizes of L. salivarius populations from broilers fed diets with different compositions, maintained at different stocking densities, or given the antimicrobial drugs bacitracin and monensin in the feed. Stocking densities did not influence the numbers of L. salivarius cells in the ileum. A diet containing meat and bone meal reduced the size of the L. salivarius population relative to that of chickens given the control diet, as did administration of bacitracin and monensin in the feed. These changes in the target bacterial population were associated with improved broiler weight gain.

Use of quantitative real-time PCR to estimate maize endogenous DNA degradation after cooking and extrusion or in food products

Polymerase chain reaction (PCR) is being used increasingly to detect DNA sequences for food quality testing for GM content, microbial contamination, and ingredient content. However, food processing often results in DNA degradation and therefore may affect the suitability of PCR or even DNA sequence detection for food quality assurance. This paper describes a novel approach using quantitative real-time PCR (qPCR) to estimate the extent of DNA degradation. With use of two maize endogenous nuclear sequences, sets of four qPCR assays were developed to amplify target sequences ranging from<100 bp to approximately 1000 bp. The maize nuclear sequences used encode chloroplastic glyceraldehyde-3-phosphate dehydrogenase and cell wall invertase. The utility of the qPCR approach for quantifying the effective concentration of maize DNA that is needed to amplify variable length DNA sequences was demonstrated using samples of maize cornmeal cooked in water for variable times, extrusion products developed using different barrel temperature and torque settings, and a range of food products from supermarket shelves. Results showed that maize DNA was substantially degraded by a number of processing procedures, including cooking for 5 min or more, extrusion at high temperatures and/or high torque settings, and in most processed foods from supermarket shelves. Processing also reduced the effective concentration of DNA sequences capable of directing amplification of the <100 bp assays as well, particularly after popping of popping corn or extrusion at a combination of high temperature and torque settings. The approach for quantifying DNA degradation described in this paper may also be of use in disciplines where understanding the extent of DNA degradation is important, such as in environmental, forensic, or historical samples.

Starvation period and age affect the response of female Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) to odor and visual cues

The effects of starvation or age on the walking or flying response of female Frankliniella occidentalis to visual and/or odor cues in two types of olfactometer were examined in the laboratory. The response of walking thrips starved for 0, 1, 4, or 24h to an odor cue (1microl of 10% p-anisaldehyde) was examined in a Y-tube olfactometer. The take-off and landing response of thrips (unknown age) starved for 0, 1, 4, 24, 48 or 72h, or of thrips of different ages (2-3 days or 10-13 days post-adult emergence) starved for 24h, to a visual cue (98 cm(2) yellow sticky trap) and/or an odor cue (0.5 or 1.0 ml p-anisaldehyde) was examined in a wind tunnel. More thrips walked up the odor-laden arm in the Y-tube when starved for at least 4h (76%) than satiated thrips (58.7%) or those starved for 1h (62.7%, P<0.05). In the wind tunnel experiments the percentage of thrips to fly or land on the sticky trap increased between satiated thrips (7.3% to fly, 3.3% on trap) and those starved for 4h (81.2% to fly, 29% on trap) and decreased between thrips starved for 48 (74.5% to fly, 23% on trap) and 72 h (56.5% to fly, 15.5% on trap, P<0.05). Fewer younger thrips (38.8%) landed on a sticky trap containing a yellow visual cue of, those that flew, than older thrips (70.4%, P<0.05), although a similar percentage of thrips flew regardless of age or type of cue present in the wind tunnel (average 44%, P>0.05).

Identification of all chromosome arms and their involvement in meiotic homoeologous associations at metaphase I in 2 Hordeum vulgare L. x Hordeum bulbosum L. hybrids

We have identified all Hordeum bulbosum chromosomes in 2 diploid Hordeum vulgare x Hordeum bulbosum hybrids using suitable probes and fluorescence in situ hybridization. Using the parental idiograms allowed us to carry out a full analysis of chromosome associations among all chromosome arms in the hybrids. Association frequencies were generally lower for the short arms than for the long arms. There were also significant differences among the chromosome arms in association frequencies, partly correlated with the absolute length of the chromosome arm, as well as with the frequency of recombinant lines, which were recovered from partially fertile interspecific hybrids. The H. bulbosum idiogram will be useful for further chromosome association studies and will enable the identification of H. bulbosum chromosomes involved in chromosome addition or substitution lines.

Reduced metaphase I associations between the short arms of homologous chromosomes in a Hordeum vulgare L. x H. bulbosum L. diploid hybrid influences the frequency of recombinant progeny

Hordeum vulgare (cultivated barley) x H. bulbosum (bulbous barley grass) hybrids have been used to obtain disease-resistant recombinant lines (RLs). The RLs contain chromatin transferred from the wild species mostly onto the long arms of recipient barley chromosomes. To determine whether differences in meiotic metaphase I (MI) associations between the long and short arms of homologous chromosomes can account for the preponderance of introgressions on the long arms, we carried out fluorescent in situ hybridisation on MI chromosome preparations obtained from pollen mother cells of a diploid interspecific hybrid. By using various probes, we established that MI associations between the long arms occurred more frequently than between the short arms for the five chromosomes tested.

Quantification of progeny classes in two facultatively apomictic accessions of Hieracium

Hieracium is an established model system for studying the cytological and genetic basis of gametophytic apomixis. In common with most known apomicts, the formation of 'maternal seed' is not exclusive in Hieracium, as apomixis operates in conjunction with a low level of sexuality. When this occurs the form of apomixis is described as 'facultative'. The formation of maternal seed in these plants is characterised by the avoidance of meiosis followed by the parthenogenetic development of an unreduced egg cell. In some ovules, however, meiosis does proceed, and sometimes the fertilisation of an egg cell presages embryogenesis. As a result, this mechanism of facultative apomixis leads to the formation of several different types of progeny, each representing a unique combination of meiosis/apomeiosis and fertilisation/parthenogenesis. Furthermore, fertilisation may involve either self or non-self pollen, leading to the recognition of six progeny classes from each individual plant. To facilitate an understanding of these processes we have developed a method for identifying individuals from different progeny classes based on the inheritance of introduced heterologous marker genes. This technique permits the screening of many thousands of seedlings at germination, and the consequent isolation of individuals associated with rare classes. Progeny profiles were determined for two apomictic accessions of Hieracium. Both were found to develop approximately 2.5% of their seed from meiotically derived eggs under the experimental conditions used and to have a rate of hybridity of approximately 2%. Evidence was also found for the action of a self-incompatibility mechanism operating in these plants despite the autonomous nature of apomixis in Hieracinum. As a demonstration of the utility of this approach, a study was conducted of polyembryony in one accession. The results indicate that there was a 7 fold greater likelihood that a meiotically derived seedling would arise in a polyembryonic seed than in a single-embryo seed. This indicates that facultative apomixis in Hieracium not only results from the simultaneous occurrence of sexual and asexual seed formation in the same capitulum as previously demonstrated, but most often as parallel processes within the same ovule.

Ruptured ectopic pregnancy after elective termination of intrauterine pregnancy discovered by use of ultrasonography in the emergency department

The authors report a case of a 27-year-old female who was diagnosed as having a ruptured ectopic pregnancy approximately 12 hours after an elective termination of an intrauterine pregnancy (IUP) was performed. Multiple previous evaluations by an obstetrician for a chief complaint of abdominal pain revealed an IUP but did not disclose the underlying pathology. The ectopic pregnancy was identified by the emergency physician's use of ultrasound in the emergency department.

Electrocautery-ignited endotracheal tube fire: case report

The risk of fire in the airway associated with laser surgery is well known, but there are reports of endotracheal tube fires ignited by electrocautery, particularly during pharyngeal surgery or tracheostomy or both. This uncommon complication has potentially devastating consequences. Surgeons undertaking these procedures should be aware of this complication and be familiar with measures to avoid them. We present a case report of an electrocautery-ignited endotracheal tube fire during an elective tracheostomy, which resulted in the patient's death.

Effect of a comprehensive program to reduce needlestick injuries

The Arlington Hospital Needlestick Injury (NSI) Prevention Program was created to protect healthcare workers from NSI and to assess the effectiveness of our interventions. Interventions included revising NSI policy and procedures. The average NSI rate dropped from 109 to 43 per year after the interventions, over a period of 4 years.

Evaluation of the Vidas Chlamydia test to detect and verify Chlamydia trachomatis in urogenital specimens

The Vidas Chlamydia test (CHL) is an automated enzyme-linked immunofluorescence assay for the detection of Chlamydia trachomatis. Positive and equivocal results are confirmed with a blocking assay. A mouse monoclonal antibody directed against the chlamydial lipopolysaccharides was used for the test. The CHL assay is widely used in Europe, but U.S. experience with it is limited. Three clinical test sites (The Arlington Hospital, Arlington, Va., Indiana University, Indianapolis, and the University of California, San Francisco) compared CHL with tissue culture (TC) for the identification of chlamydia in urogenital specimens (2,453 females and 850 males). True positives (TP) were defined as either TC positive or TC negative and CHL positive by a positive direct fluorescent-antibody assay or PCR test. Overall prevalence was 5.5% for females, 10.3% for male urethral swabs, and 10.7% for combined male TC urethral swabs and CHL with first catch urine (FCU) specimens. Compared to TP, CHL and TC had sensitivities of 89.6 and 94.1% with female cervical swabs and 90.9 and 86.4% with male urethral swabs, respectively. CHL sensitivity was 81.2 for male FCU specimens and 77.7% for matching male TC swabs. There were relatively few false-positive results, with all specificities being >99.4%. With the blocking assay, Vidas CHL specificity was >99.7%. However, male FCU specimen sensitivity was compromised because 9.2% (7 of 76) of the TP were initially positive but were not confirmed. An improvement in the Vidas blocking assay is needed before we can recommend its use with male urine. Alternatively, one could argue that the specificity of the test is so high that a confirmatory assay is not needed. For male and female swabs, the Vidas CHL assay has a performance that is similar to that of TC.

Cellular immunity to cartilage aggrecan core protein in patients with rheumatoid arthritis and non-arthritic controls

OBJECTIVE

To identify antigen(s) among purified deglycosylated aggrecan peptides spanning the chondroitin sulphate domain that may be responsible for the initiation or perpetuation of the autoimmune responses in rheumatoid arthritis (RA).

METHODS

Aggrecan was purified from human articular cartilage and deglycosylated with either bacterial glycosidases or trifluoromethanesulphonic acid (TFMS). Twelve overlapping peptides (15 residues) spanning the chondroitin sulphate domain with N-terminal residues offset by three amino acids were synthesised. T cell responses to these antigens in RA patients and age matched controls were assessed in vitro by antigen specific T cell proliferation assays.

RESULTS

Enzymically deglycosylated aggrecan (EDA) stimulated proliferation of T cells isolated from the peripheral blood in a greater proportion of patients with RA than controls. In a subset (12.5%) of RA patients, the magnitude of stimulation lay outside the control range. T cell proliferative responses to TFMS treated aggrecan were greater than, but well correlated with, responses to EDA. T cells from 15 patients were also stimulated with the pooled synthetic peptides. Four of seven patients who demonstrated T cell reactivity to EDA (seven of 15) also showed enhanced T cell proliferation to synthetic peptides.

CONCLUSION

These data suggest that an autoantigenic T cell epitope may lie within the chondroitin sulphate domain of aggrecan.

Use of 0.3% triclosan (Bacti-Stat) to eradicate an outbreak of methicillin-resistant Staphylococcus aureus in a neonatal nursery

BACKGROUND

Once established in an institution, methicillin-resistant Staphylococcus aureus (MRSA) outbreaks have proved difficult to eradicate, despite intensive infection control measures. This report describes the nosocomial infection with MRSA of 22 male infants in a neonatal nursery during a 7-month period and the infection control procedures that effectively brought this outbreak under control and eliminated recurrence for more than 3 1/2 years.

METHODS

After a single index case of bullous impetigo caused by MRSA in a neonate discharged from the nursery 2 weeks previously, an additional 18 cases of MRSA skin infections were clustered in a 7-week period. Aggressive infection control measures were instituted, including changes in umbilical cord care, circumcision procedures, diapers, handwashing, gloves, gowns, linens, disinfection, placement in cohorts of neonates and staff, surveillance, and monitoring.

RESULTS

These measures were not effective in slowing the outbreak. The single additional measure of changing handwashing and bathing soap to a preparation containing 0.3% triclosan (Bacti-Stat) was associated with the immediate termination of the acute phase of the MRSA outbreak.

CONCLUSION

The nursery has remained free of MRSA for more than 3 1/2 years, attesting to the success of our program.

Resistance of cowpea [Vigna unguiculata (L.) Walp.] to Striga gesnerioides (Willd.) Vatke, a parasitic angiosperm

An in vitro growth system was used to investigate the expression of resistance of cowpea [Vigna unguiculata (L.) Walp.] varieties B301 and 58-57 to the angiosperm parasite Striga gesnerioides (Willd.) Vatke. Variety Blackeye was included in experiments as a susceptible control. Seeds of S. gesnerioides germinated on the roots of all varieties. Two different mechanisms of resistance were expressed in B301 and 58-57 after penetration of host roots by parasite radicles. The first mechanism was expressed in both varieties; host tissue around invading Striga radicles became necrotic in association with the early death of the parasite and lack of tubercle formation. On variety 58-57, the necrosis response was expressed only when the roots were inoculated with Striga from Burkina Faso but Striga from Mali successfully parasitized the roots of variety 58-57. The second mechanism was observed only on variety B301. Striga radicles infected cowpea roots, tubercles were formed but remained at 1-2 mm in diameter with very limited stem growth. No further development of the parasite occurred in vitro or when infected cowpeas were grown in soil or vermiculite. Similarities between the expression of resistance of cowpea to Striga and ot plants to plant pathogenic fungi are discussed.

Dosage effects of pulsed steroid therapy on serum cortisol levels in oral and maxillofacial surgery patients

The purpose of this study was to determine the effects of two dosage regimens of dexamethasone on the serum cortisol levels of a group of patients undergoing major maxillofacial surgical procedures. Analysis of the data demonstrated that the use of dexamethasone, 10 to 20 mg intravenously given every 3 hours intraoperatively and every 4 hours postoperatively over 24 hours, followed by a repository dose of 80 mg of intramuscular methylprednisolone, causes short-term serum cortisol suppression. The maximum depression occurred on postoperative day 3; normal levels were restored by postoperative day 7. Therefore, pulsed therapy can be considered relatively safe when known contraindications have been considered.