Mycelial biomass and concentration of loline alkaloids driven by complex population structure in Epichloë uncinata and meadow fescue (Schedonorus pratensis).

Many efforts have been made to select and isolate naturally occurring animal-friendly Epichloë strains for later reinfection into elite cultivars. Often this process involves large-scale screening of Epichloë-infected wild grass populations where strains are characterized and alkaloids measured. Here, we describe for the first time the use of genotyping-by-sequencing (GBS) on a collection of 217 Epichloë-infected grasses (7 S. arundinaceum, 4 L. perenne, and 206 S. pratensis). This genotyping strategy is cheaper than complete genome sequencing, is suitable for a large number of individuals, and, when applied to endophyte-infected grasses, conveniently genotypes both organisms. In total, 6273 single nucleotide polymorphisms (SNPs) in the endophyte data set and 38 323 SNPs in the host data set were obtained. Our findings reveal a composite structure with three distinct endophyte clusters unrelated to the three main S. pratensis gene pools that have most likely spread from different glacial refugia in Eurasia. All three gene pools can establish symbiosis with E. uncinata. A comparison of the endophyte clusters with microsatellite-based fingerprinting of the same samples allows a quick test to discriminate between these clusters using two simple sequence repeats (SSRs). Concentrations of loline alkaloids and mycelial biomass are correlated and differ significantly among the plant and endophyte subpopulations; one endophyte strain has higher levels of lolines than others, and one specific host genotype is particularly suitable to host E. uncinata. These findings pave the way for targeted artificial inoculations of specific host-endophyte combinations to boost loline production in the symbiota and for genome association studies with the aim of isolating genes involved in the compatibility between meadow fescue and E. uncinata.

Transcriptome sequencing of Festulolium accessions under salt stress.

OBJECTIVES: The objective of this study was to establish transcriptome assemblies of Festulolium hybrids under salt stress, and identify genes regulated across the hybrids in response to salt stress. The development of transcriptome assemblies for Festulolium hybrids and cataloguing of genes regulated under salt stress will facilitate further downstream studies. RESULTS: Plants were grown at three salt concentrations (0.5%, 1% and 1.5%) and phenotypic and transcriptomic data was collected. Salt stress was confirmed by progressive loss of green leaves as salt concentration increased from 0 to 1.5%. We generated de-novo transcriptome assemblies for two Festulolium pabulare festucoid genotypes, for a single Festulolium braunii genotype, and a single F. pabulare loloid genotype. We also identified 1555 transcripts that were up regulated and 1264 transcripts that were down regulated in response to salt stress in the Festulolium hybrids. Some of the identified transcripts showed significant sequence similarity with genes known to be regulated during salt and other abiotic stresses.

Ambient and at-the-ear occupational noise exposure and serum lipid levels.

OBJECTIVES: Occupational and residential noise exposure has been related to increased risk of cardiovascular disease. Alteration of serum lipid levels has been proposed as a possible causal pathway. The objective of this study was to investigate the relation between ambient and at-the-ear occupational noise exposure and serum levels of total cholesterol, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and triglycerides when accounting for well-established predictors of lipid levels. METHODS: This cross-sectional study included 424 industrial workers and 84 financial workers to obtain contrast in noise exposure levels. They provided a serum sample and wore portable dosimeters that every 5-s recorded ambient noise exposure levels during a 24-h period. We extracted measurements obtained during work and calculated the full-shift mean ambient noise level. For 331 workers who kept a diary on the use of a hearing protection device (HPD), we subtracted 10 dB from every noise recording obtained during HPD use and estimated the mean full-shift noise exposure level at the ear. RESULTS: Mean ambient noise level was 79.9 dB (A) [range 55.0-98.9] and the mean estimated level at the ear 77.8 dB (A) [range 55.0-94.2]. Ambient and at-the-ear noise levels were strongly associated with increasing levels of triglycerides, cholesterol-HDL ratio, and decreasing levels of HDL-cholesterol, but only in unadjusted analyses that did not account for HPD use and other risk factors. CONCLUSION: No associations between ambient or at-the-ear occupational noise exposure and serum lipid levels were observed. This indicates that a causal pathway between occupational and residential noise exposure and cardiovascular disease does not include alteration of lipid levels.

Prevalence and heritability of symptomatic syringomyelia in Cavalier King Charles Spaniels and long-term outcome in symptomatic and asymptomatic littermates.

BACKGROUND: Syringomyelia (SM) is common in the Cavalier King Charles Spaniel (CKCS). Dogs with syringes express clinical signs or might be clinically silent. OBJECTIVES: To investigate the prevalence and heritability of symptomatic SM, the association between clinical signs and magnetic resonance imaging (MRI) findings, and long-term outcome. ANIMALS: All CKCS registered in the Danish Kennel Club in 2001 (n = 240). METHODS: A cross-sectional questionnaire-based prevalence study validated by telephone interviews and clinically investigated clinical signs of SM. Dogs were 6 years at the time of investigation. A prospective observational litter study including clinical investigations, MRI and 5-year follow-up of symptomatic and asymptomatic siblings. Heritability was estimated based on the scale of liability in the study population and litter cohort. RESULTS: The cross-sectional study estimated a prevalence of symptomatic SM at 15.4% in the population. Thirteen symptomatic and 9 asymptomatic siblings participated in the litter study. Spinal cord syringes were confirmed in 21 of 22 littermates (95%). Syrinx diameter and mean syrinx : spinal cord ratio were significantly correlated with clinical signs (P < .01). Estimated heritability of symptomatic SM was 0.81. Symptomatic SM motivated euthanasia in 20%. Dogs with syringes, which expressed no clinical signs at the age of 6, remained asymptomatic in 14/15 cases (93%). CONCLUSIONS AND CLINICAL IMPORTANCE: The prevalence of symptomatic SM is high and genetics have a high impact on clinical disease expression. Further investigations of factors influencing the outbreak threshold of clinical signs of SM are desirable.

Randomized study comparing endoscopic ultrasound-guided Trucut biopsy and fine needle aspiration with high suction.

OBJECTIVES: Endoscopic ultrasound (EUS)-guided Trucut biopsy (TCB) enables acquisition of tissue cores for histological assessment. Because of the rigid needle and the spring mechanism, tissue acquisition can be difficult from regions that require sharp angulation of the echoendoscope. Fine needle aspiration with high suction (FNAHS) has been proposed as a method to obtain histological tissue cores while affording the flexibility to obtain specimens even with extreme endoscope angulation. The objective was to compare prospectively these two methods in their ability to obtain specimens for histological assessment and in their diagnostic accuracy, including cytological diagnosis when achieved. METHODS: Eighty lesions in 77 patients were amenable to transoesophageal, transgastric or transrectal biopsy and were randomized to TCB (n = 44) or FNAHS (n = 36). Each specimen was assessed for adequacy (scoring system where a score of 0 was no material, 1-2 was considered cytological, and 3-5 was considered histological). Follow-up information was obtained to establish a gold standard final diagnosis. RESULTS: The median histological scores for FNAHS and TCB were 2 and 5, respectively. Histological cores were obtained in 95.3% of TCB, as opposed to 27.8% in the FNAHS group (P < 0.0001). Although the diagnostic accuracy for TCB was greater than that for FNAHS (88.3% and 77.8%, respectively), this was not statistically significant (P = 0.24). CONCLUSION: If histological information is required, TCB is superior to FNAHS. The difference in diagnostic accuracy did not reach statistical significance due to low numbers and the fact that FNAHS often enabled a cytological diagnosis.

A meta-analysis comparing the effect of vaccines against Mycoplasma hyopneumoniae on daily weight gain in pigs.

Our aims were to evaluate the published literature concerning the effect of swine vaccination against Mycoplasma hyopneumoniae on the average daily weight gain (ADWG). This was done by re-evaluating the influence of selected factors on ADWG by a meta-analysis of published studies from 1991 to 1999, fulfilling certain inclusion criteria. With ADWG as the outcome, an analysis of variance was performed for such variables as treatment, vaccination schedule, age during study, housing system and publication quality. Each clinical trial was considered as a random effect and the numbers of pigs in each trial were weightings. Of 63 published studies, 16 describing three commercial vaccines fulfilled the criteria for the meta-analysis. Due to few studies with one of the vaccines (n=3), only two vaccines were included. Vaccinated pigs gained an average of 592g (S.E.=15) with Stellamune and 590g (S.E.=15) with Suvaxyne compared to non-vaccinated pigs that gained an average of 569g (S.E.=14)(P<0.01) when adjusted for age during the study. Vaccine type, vaccination schedule, housing system and publication quality were not significantly associated with ADWG.

Fine-needle aspiration cytology of pancreatoblastoma.

Pancreatoblastoma is a rare pancreatic neoplasm seen most commonly in the pediatric age group. We report on the aspiration cytology and immunohistochemical findings of a pancreatoblastoma in a 16-yr-old male.

A TERMINAL FLOWER1-like gene from perennial ryegrass involved in floral transition and axillary meristem identity.

Control of flowering and the regulation of plant architecture have been thoroughly investigated in a number of well-studied dicot plants such as Arabidopsis, Antirrhinum, and tobacco. However, in many important monocot seed crops, molecular information on plant reproduction is still limited. To investigate the regulation of meristem identity and the control of floral transition in perennial ryegrass (Lolium perenne) we isolated a ryegrass TERMINAL FLOWER1-like gene, LpTFL1, and characterized it for its function in ryegrass flower development. Perennial ryegrass requires a cold treatment of at least 12 weeks to induce flowering. During this period a decrease in LpTFL1 message was detected in the ryegrass apex. However, upon subsequent induction with elevated temperatures and long-day photoperiods, LpTFL1 message levels increased and reached a maximum when the ryegrass apex has formed visible spikelets. Arabidopsis plants overexpressing LpTFL1 were significantly delayed in flowering and exhibited dramatic changes in architecture such as extensive lateral branching, increased growth of all vegetative organs, and a highly increased trichome production. Furthermore, overexpression of LpTFL1 was able to complement the phenotype of the severe tfl1-14 mutant of Arabidopsis. Analysis of the LpTFL1 promoter fused to the UidA gene in Arabidopsis revealed that the promoter is active in axillary meristems, but not the apical meristem. Therefore, we suggest that LpTFL1 is a repressor of flowering and a controller of axillary meristem identity in ryegrass.

The role of fine-needle aspiration cytology in the evaluation of metastatic clear cell tumors.

BACKGROUND: Clear cell tumors (CCTs) occur as primary neoplasms in a number of anatomic sites. Due to their overlapping morphologic features, these tumors can be challenging for the cytologist, particularly when they present as metastatic lesions. METHODS: Forty-nine fine-needle aspirations (FNA) of metastatic CCTs from 46 patients (age range, 29-87 years; mean, 64 years) were reviewed retrospectively. In addition to the routine smears and cell block preparations, ancillary studies were performed in selected cases. Clinical and/or histologic follow-up was obtained for all patients. RESULTS: The sites of the 49 FNAs were the lung (12 cases), lymph nodes (9 cases), liver (7 cases), bone (7 cases), soft tissue (4 cases), pelvis (2 cases), adrenal gland (2 cases), pancreas (1 case), thyroid (2 cases), peritoneum (2 cases), and vagina (1 case). Twenty-seven patients had a previous history of a CCT and the FNA material in these cases was consistent with a metastasis. The primary anatomic sites in these cases were the kidney (20 cases), ovary (2 cases), salivary gland (1 case), and cervix (1 case). On light microscopy, these tumors had a similar appearance and often were indistinguishable. Nineteen patients did not have a prior history of malignancy; 12 of these patients had a concurrent renal mass and the diagnosis of metastatic renal cell carcinoma was made. The anatomic site of origin of seven of the ten remaining tumors (kidney [2 cases], lung [2 cases], ovary [1 case], germ cell [1 case], and endometrium [1 case]) was established through immunocytochemical studies of cytologic material and clinical follow-up. CONCLUSIONS: FNA plays an important role in the diagnosis of metastatic CCT. Cytologic examination, ancillary studies, and clinical information can establish the anatomic site of origin in the majority (95%) of cases, precluding the necessity of obtaining additional tissue. Cancer (Cancer Cytopathol)

Blocking Gibbs sampling for linkage analysis in large pedigrees with many loops.

We apply the method of "blocking Gibbs" sampling to a problem of great importance and complexity-linkage analysis. Blocking Gibbs sampling combines exact local computations with Gibbs sampling, in a way that complements the strengths of both. The method is able to handle problems with very high complexity, such as linkage analysis in large pedigrees with many loops, a task that no other known method is able to handle. New developments of the method are outlined, and it is applied to a highly complex linkage problem in a human pedigree.

Problems with determination of noncommunicating classes for Monte Carlo Markov chain applications in pedigree analysis.

Exact calculations for probabilities on complex pedigrees are computationally intensive and very often infeasible. Markov chain Monte Carlo methods are frequently used to approximate probabilities and likelihoods of interest. However, when a locus with more than two alleles is considered, the underlying Markov chain is not guaranteed to be irreducible and the results of such analyses are unreliable. A method for finding the noncommunicating classes of the Markov chain would be very useful in designing algorithms that can jump between these classes. In this paper, we will examine some existing work on this problem and point out its limitations. We will also comment on the difficulty of developing a useful algorithm.

Mucinous tumors of the ovary: interobserver diagnostic variability and utility of sectioning protocols.

OBJECTIVES: To determine the interobserver variability of the subclassification of ovarian mucinous tumors and the utility of different sectioning protocols. METHODS: Six pathologists retrospectively reclassified 73 mucinous tumors (30 adenomas, 22 low malignant potential tumors, and 21 carcinomas). Using probabilities, the accuracy of limited sectioning protocols was compared with that of a one section per centimeter protocol. RESULTS: The mean kappa statistic was 0.56, indicating only good agreement. Although a limited sectioning protocol would result in misdiagnosing cases of stage IA carcinoma as a low malignant potential tumor, the overall prognosis of patients with low malignant potential tumors would not markedly change. The prognosis of a patient with a low malignant potential tumor using limited sectioning was within the prognostic range owing to interobserver variability alone. CONCLUSIONS: We conclude that extensive sectioning of ovarian mucinous tumors has limited benefit.

Telecytology: diagnostic accuracy in cervical-vaginal smears.

Although cervical-vaginal telecytology is a promising tool, diagnostic accuracy has not been extensively evaluated. The authors examined the accuracy of five cytotechnologists who retrospectively reviewed 50 cervical-vaginal smears using the video monitor, and 2 months later, using the light microscope. Accuracy was expressed in terms of crude agreement with the original diagnosis and number of false positives (FPs) and false negatives (FNs). With a greater than one step difference as discrepant, the group crude agreement using the video monitor and the light microscope was 85.6% and 95.6%, respectively. The group number of FNs and FPs for the light microscope was 8 and 7, respectively, and for the video monitor was 34 and 7, respectively. There was a wide range of individual performance. We conclude that accuracy of telecytology is high, but less than that of light microscopy. The major reason for lower telecytologic accuracy was undercalling dysplasia.

Low-grade transitional cell carcinoma of the urinary bladder: application of select cytologic criteria to improve diagnostic accuracy [corrected].

The cytologic diagnosis of low-grade transitional cell carcinoma of the bladder is difficult, and the reported sensitivity of a positive diagnosis ranges from 0 to 73%. Using regression analysis, our laboratory previously reported the criteria of increased nuclear/cytoplasmic ratios, irregular nuclear membranes, and cytoplasmic homogeneity as indicative of low-grade transitional cell carcinoma. To examine the validity of these criteria, six observers examined 88 bladder-wash specimens (39 transitional cell carcinomas and 49 benign) and, using the selected criteria, graded each wash for the probability of malignancy. Diagnostic accuracy was measured using the receiver operating characteristic curve and the likelihood ratio. Overall observer accuracy was 76%, the sensitivity of a definitive negative diagnosis was 82%, and the specificity of a definitive positive diagnosis was 96%. We conclude that key cytologic criteria can be learned and effectively applied with high accuracy. Observer variation in diagnostic categories might reflect different confidence levels and probabilities of transitional cell carcinoma.